Use of a Walk Through Time to Facilitate Student Understandings of the Geological Time Scale

NASA Astrophysics Data System (ADS)

Shipman, H. L.

2004-12-01

Students often have difficulties in appreciating just how old the earth and the universe are. While they can simply memorize a number, they really do not understand just how big that number really is, in comparison with other, more familiar student referents like the length of a human lifetime or how long it takes to eat a pizza. (See, e.g., R.D. Trend 2001, J. Research in Science Teaching 38(2): 191-221) Students, and members of the general public, also display such well-known misconceptions as the "Flintstone chronology" of believing that human beings and dinosaurs walked the earth at the same time. (In the classic American cartoon "The Flintstones," human beings used dinosaurs as draft animals. As scientists we know this is fiction, but not all members of the public understand that.) In an interdisciplinary undergraduate college class that dealt with astronomy, cosmology, and biological evolution, I used a familiar activity to try to improve student understanding of the concept of time's vastness. Students walked through a pre-determined 600-step path which provided a spatial analogy to the geological time scale. They stopped at various points and engaged in some pre-determined discussions and debates. This activity is as old as the hills, but reports of its effectiveness or lack thereof are quite scarce. This paper demonstrates that this activity was effective for a general-audience, college student population in the U.S. The growth of student understandings of the geological time scale was significant as a result of this activity. Students did develop an understanding of time's vastness and were able to articulate this understanding in various ways. This growth was monitored through keeping track of several exam questions and through pre- and post- analysis of student writings. In the pre-writings, students often stated that they had "no idea" about how to illustrate the size of the geological time scale to someone else. While some post-time walk responses simply restated what was done in the walk through time, some students were able to develop their own ways of conceptualizing the vastness of the geological time scale. A variety of findings from student understandings will be presented. This work has been supported in part by the Distinguished Scholars Program of the National Science Foundation (DUE-0308557).

Once in a Million Years: Teaching Geologic Time

ERIC Educational Resources Information Center

Lewis, Susan E.; Lampe, Kristen A.; Lloyd, Andrew J.

2005-01-01

The authors advocate that students frequently lack fundamental numerical literacy on the order of millions or billions, and that this comprehension is critical to grasping key evolutionary concepts related to the geologic time scale, the origin and diversification of life on earth, and other concepts such as the national debt, human population…

Map of surficial deposits and materials in the eastern and central United States (east of 102 degrees West longitude)

USGS Publications Warehouse

Fullerton, David S.; Bush, Charles A.; Pennell, Jean N.

2003-01-01

This data set contains surficial geologic units in the Eastern and Central United States, as well as a glacial limit line showing the position of maximum glacial advance during various geologic time periods. The geologic units represent surficial deposits and other surface materials that accumulated or formed during the past 2+ million years, such as soils, alluvium, and glacial deposits. These surface materials are referred to collectively by many geologists as regolith, the mantle of fragmented and generally unconsolidated material that overlies the bedrock foundation of a continent. This data set and the printed map produced from it, U.S. Geological Survey (USGS) Geologic Investigation Series I-2789, were based on 31 published maps in the USGS's Quaternary Geologic Atlas of the United States map series (USGS Miscellaneous Investigations Series I-1420). The data were compiled at 1:1,000,000 scale, to be viewed as a digital map at 1:2,000,000 nominal scale and to be printed as a conventional paper map at 1:2,500,000 scale.

Decoupling processes and scales of shoreline morphodynamics

USGS Publications Warehouse

Hapke, Cheryl J.; Plant, Nathaniel G.; Henderson, Rachel E.; Schwab, William C.; Nelson, Timothy R.

2016-01-01

Behavior of coastal systems on time scales ranging from single storm events to years and decades is controlled by both small-scale sediment transport processes and large-scale geologic, oceanographic, and morphologic processes. Improved understanding of coastal behavior at multiple time scales is required for refining models that predict potential erosion hazards and for coastal management planning and decision-making. Here we investigate the primary controls on shoreline response along a geologically-variable barrier island on time scales resolving extreme storms and decadal variations over a period of nearly one century. An empirical orthogonal function analysis is applied to a time series of shoreline positions at Fire Island, NY to identify patterns of shoreline variance along the length of the island. We establish that there are separable patterns of shoreline behavior that represent response to oceanographic forcing as well as patterns that are not explained by this forcing. The dominant shoreline behavior occurs over large length scales in the form of alternating episodes of shoreline retreat and advance, presumably in response to storms cycles. Two secondary responses include long-term response that is correlated to known geologic variations of the island and the other reflects geomorphic patterns with medium length scale. Our study also includes the response to Hurricane Sandy and a period of post-storm recovery. It was expected that the impacts from Hurricane Sandy would disrupt long-term trends and spatial patterns. We found that the response to Sandy at Fire Island is not notable or distinguishable from several other large storms of the prior decade.

Velocity Model Analysis Based on Integrated Well and Seismic Data of East Java Basin

NASA Astrophysics Data System (ADS)

Mubin, Fathul; Widya, Aviandy; Eka Nurcahya, Budi; Nurul Mahmudah, Erma; Purwaman, Indro; Radityo, Aryo; Shirly, Agung; Nurwani, Citra

2018-03-01

Time to depth conversion is an important processof seismic interpretationtoidentify hydrocarbonprospectivity. Main objectives of this research are to minimize the risk of error in geometry and time to depth conversion. Since it’s using a large amount of data and had been doing in the large scale of research areas, this research can be classified as a regional scale research. The research was focused on three horizons time interpretation: Top Kujung I, Top Ngimbang and Basement which located in the offshore and onshore areas of east Java basin. These three horizons was selected because they were assumed to be equivalent to the rock formation, which is it has always been the main objective of oil and gas exploration in the East Java Basin. As additional value, there was no previous works on velocity modeling for regional scale using geological parameters in East Java basin. Lithology and interval thickness were identified as geological factors that effected the velocity distribution in East Java Basin. Therefore, a three layer geological model was generated, which was defined by the type of lithology; carbonate (layer 1: Top Kujung I), shale (layer 2: Top Ngimbang) and Basement. A statistical method using three horizons is able to predict the velocity distribution on sparse well data in a regional scale. The average velocity range for Top Kujung I is 400 m/s - 6000 m/s, Top Ngimbang is 500 m/s - 8200 m/s and Basement is 600 m/s - 8000 m/s. Some velocity anomalies found in Madura sub-basin area, caused by geological factor which identified as thick shale deposit and high density values on shale. Result of velocity and depth modeling analysis can be used to define the volume range deterministically and to make geological models to prospect generation in details by geological concept.

Rheological behavior of the crust and mantle in subduction zones in the time-scale range from earthquake (minute) to mln years inferred from thermomechanical model and geodetic observations

NASA Astrophysics Data System (ADS)

Sobolev, Stephan; Muldashev, Iskander

2016-04-01

The key achievement of the geodynamic modelling community greatly contributed by the work of Evgenii Burov and his students is application of "realistic" mineral-physics based non-linear rheological models to simulate deformation processes in crust and mantle. Subduction being a type example of such process is an essentially multi-scale phenomenon with the time-scales spanning from geological to earthquake scale with the seismic cycle in-between. In this study we test the possibility to simulate the entire subduction process from rupture (1 min) to geological time (Mln yr) with the single cross-scale thermomechanical model that employs elasticity, mineral-physics constrained non-linear transient viscous rheology and rate-and-state friction plasticity. First we generate a thermo-mechanical model of subduction zone at geological time-scale including a narrow subduction channel with "wet-quartz" visco-elasto-plastic rheology and low static friction. We next introduce in the same model classic rate-and state friction law in subduction channel, leading to stick-slip instability. This model generates spontaneous earthquake sequence. In order to follow in details deformation process during the entire seismic cycle and multiple seismic cycles we use adaptive time-step algorithm changing step from 40 sec during the earthquake to minute-5 year during postseismic and interseismic processes. We observe many interesting deformation patterns and demonstrate that contrary to the conventional ideas, this model predicts that postseismic deformation is controlled by visco-elastic relaxation in the mantle wedge already since hour to day after the great (M>9) earthquakes. We demonstrate that our results are consistent with the postseismic surface displacement after the Great Tohoku Earthquake for the day-to-4year time range.

Large-scale mapping of landslides in the epicentral area Loma Prieta earthquake of October 17, 1989, Santa Cruz County

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spittler, T.E.; Sydnor, R.H.; Manson, M.W.

1990-01-01

The Loma Prieta earthquake of October 17, 1989 triggered landslides throughout the Santa Cruz Mountains in central California. The California Department of Conservation, Division of Mines and Geology (DMG) responded to a request for assistance from the County of Santa Cruz, Office of Emergency Services to evaluate the geologic hazard from major reactivated large landslides. DMG prepared a set of geologic maps showing the landslide features that resulted from the October 17 earthquake. The principal purpose of large-scale mapping of these landslides is: (1) to provide county officials with regional landslide information that can be used for timely recovery ofmore » damaged areas; (2) to identify disturbed ground which is potentially vulnerable to landslide movement during winter rains; (3) to provide county planning officials with timely geologic information that will be used for effective land-use decisions; (4) to document regional landslide features that may not otherwise be available for individual site reconstruction permits and for future development.« less

Maximum rates of climate change are systematically underestimated in the geological record.

PubMed

Kemp, David B; Eichenseer, Kilian; Kiessling, Wolfgang

2015-11-10

Recently observed rates of environmental change are typically much higher than those inferred for the geological past. At the same time, the magnitudes of ancient changes were often substantially greater than those established in recent history. The most pertinent disparity, however, between recent and geological rates is the timespan over which the rates are measured, which typically differ by several orders of magnitude. Here we show that rates of marked temperature changes inferred from proxy data in Earth history scale with measurement timespan as an approximate power law across nearly six orders of magnitude (10(2) to >10(7) years). This scaling reveals how climate signals measured in the geological record alias transient variability, even during the most pronounced climatic perturbations of the Phanerozoic. Our findings indicate that the true attainable pace of climate change on timescales of greatest societal relevance is underestimated in geological archives.

How Do Novice and Expert Learners Represent, Understand, and Discuss Geologic Time?

NASA Astrophysics Data System (ADS)

Layow, Erica Amanda

This dissertation examined the representations novice and expert learners constructed for the geologic timescale. Learners engaged in a three-part activity. The purpose was to compare novice learners' representations to those of expert learners. This provided insight into the similarities and differences between their strategies for event ordering, assigning values and scale to the geologic timescale model, as well as their language and practices to complete the model. With a qualitative approach to data analysis informed by an expert-novice theoretical framework grounded in phenomenography, learner responses comprised the data analyzed. These data highlighted learners' metacognitive thoughts that might not otherwise be shared through lectures or laboratory activities. Learners' responses were analyzed using a discourse framework that positioned learners as knowers. Novice and expert learners both excelled at ordering and discussing events before the Phanerozoic, but were challenged with events during the Phanerozoic. Novice learners had difficulty assigning values to events and establishing a scale for their models. Expert learners expressed difficulty with determining a scale because of the size of the model, yet eventually used anchor points and unitized the model to establish a scale. Despite challenges constructing their models, novice learners spoke confidently using claims and few hedging phrases indicating their confidence in statements made. Experts used more hedges than novices, however the hedging comments were made about more complex conceptions. Using both phenomenographic and discourse analysis approaches for analysis foregrounded learners' discussions of how they perceived geologic time and their ways of knowing and doing. This research is intended to enhance the geoscience community's understanding of the ways novice and expert learners think and discuss conceptions of geologic time, including the events and values of time, and the strategies used to determine accuracy of scale. This knowledge will provide a base from which to support geoscience curriculum development at the university level, specifically to design activities that will not only engage and express learners' metacognitive scientific practices, but to encourage their construction of scientific identities and membership in the geoscience community.

Hands On Earth Science.

ERIC Educational Resources Information Center

Weisgarber, Sherry L.; Van Doren, Lisa; Hackathorn, Merrianne; Hannibal, Joseph T.; Hansgen, Richard

This publication is a collection of 13 hands-on activities that focus on earth science-related activities and involve students in learning about growing crystals, tectonics, fossils, rock and minerals, modeling Ohio geology, geologic time, determining true north, and constructing scale-models of the Earth-moon system. Each activity contains…

The contributions of Ranger photographs to understanding the geology of the moon

NASA Technical Reports Server (NTRS)

Trask, N. J.

1972-01-01

Vidicon photographs returned to earth by Rangers 7, 8, and 9 in 1964 and 1965 were used to study the details of lunar geologic units previously recognized from earth-based telescopic photographs and to make geologic maps at a variety of scales. The photographs from each mission changed continuously in scale as the spacecraft approached impact. The final frames had resolutions some 1,000 times better than the best earthbased photographs. Lunar stratigraphic units mapped at a scale of 1:1,000,000 displayed, at these larger scales, differences in properties and, possibly, in ages, but a clear-cut stratigraphic succession of subunits was not apparent. The plains-forming materials in both terra and mare were divisible into units mainly on the basis of the differences in the total number of superposed craters and in the relative number of craters of various morphologic types.

Using an Artificial Rock Outcrop to Teach Geology

ERIC Educational Resources Information Center

Totten, Iris

2005-01-01

Teaching Earth science without exposure to rock outcrops limits students depth of understanding of Earth's processes, limits the concept of scale from their spatial visualization imaging, and distorts their perception of geologic time (Totten 2003). Through a grant funded by the National Science Foundation, an artificial rock outcrop was…

How-to-Do-It. How Long Is a Long Time?

ERIC Educational Resources Information Center

McComas, William F.

1990-01-01

Presented is an activity designed to help students understand and appreciate the scale and order of the geologic timetable and begin to infer a relationship between biologic, chemical, and geological events. Procedures, background information, student worksheets with answers, and a list of materials are included. (CW)

A global cyclostratigraphic framework constrains the timing and pacing of environmental changes over the Late Devonian (Frasnian - Famennian) mass extinction

NASA Astrophysics Data System (ADS)

De Vleeschouwer, David; Da Silva, Anne-Christine; Day, James E.; Whalen, Michael; Claeys, Philippe

2016-04-01

Milankovitch cycles (obliquity, eccentricity and precession) result in changes in the distribution of solar energy over seasons, as well as over latitudes, on time scales of ten thousands of years to millions of years. These changing patterns in insolation have induced significant variations in Earth's past climate over the last 4.5 billion years. Cyclostratigraphy and astrochronology utilize the geologic imprint of such quasi-cyclic climatic variations to measure geologic time. In recent years, major improvements of the Geologic Time Scale have been proposed through the application of cyclostratigraphy, mostly for the Mesozoic and Cenozoic (Gradstein et al., 2012). However, the field of Paleozoic cyclostratigraphy and astrochronology is still in its infancy and the application of cyclostratigraphic techniques in the Paleozoic allows for a whole new range of research questions. For example, unraveling the timing and pacing of environmental changes over the Late Devonian mass extinction on a 105-year time-scale concerns such a novel research question. Here, we present a global cyclostratigraphic framework for late Frasnian to early Famennian climatic and environmental change, through the integration of globally distributed sections. The backbone of this relative time scale consists of previously published cyclostratigraphies for western Canada and Poland (De Vleeschouwer et al., 2012; De Vleeschouwer et al., 2013). We elaborate this Euramerican base by integrating new proxy data -interpreted in terms of astronomical climate forcing- from the Iowa basin (USA, magnetic susceptibility and carbon isotope data) and Belgium (XRF and carbon isotope data). Next, we expand this well-established cyclostratigraphic framework towards the Paleo-Tethys Ocean, using magnetic susceptibility and carbon isotope records from the Fuhe section in South China (Whalen et al., 2015). The resulting global cyclostratigraphic framework implies an important refinement of the late Frasnian to early Famennian stratigraphy, but also allows for an evaluation of the role of astronomical forcing in perturbing the global carbon cycle and pacing anoxic conditions throughout the Late Devonian mass extinction event. The late Frasnian anoxic Kellwasser events, for example, each represent only a portion of a 405-kyr eccentricity cycle, with the onset of both events separated by 500-600 kyr. References: De Vleeschouwer, D., Whalen, M. T., Day, J. E., and Claeys, P., 2012, Cyclostratigraphic calibration of the Frasnian (Late Devonian) time scale (western Alberta, Canada): Geological Society of America Bulletin, v. 124, no. 5-6, p. 928-942. De Vleeschouwer, D., Rakociński, M., Racki, G., Bond, D. P., Sobień, K., and Claeys, P., 2013, The astronomical rhythm of Late-Devonian climate change (Kowala section, Holy Cross Mountains, Poland): Earth and Planetary Science Letters, v. 365, p. 25-37. Gradstein, F. M., Ogg, J. G., Schmitz, M., and Ogg, G., 2012, The Geologic Time Scale 2012 2-Volume Set, Elsevier. Whalen, M. T., Śliwiński, M. G., Payne, J. H., Day, J. E., Chen, D., and da Silva, A.-C., 2015, Chemostratigraphy and magnetic susceptibility of the Late Devonian Frasnian-Famennian transition in western Canada and southern China: implications for carbon and nutrient cycling and mass extinction: Geological Society, London, Special Publications, v. 414.

Unsupervised learning on scientific ocean drilling datasets from the South China Sea

NASA Astrophysics Data System (ADS)

Tse, Kevin C.; Chiu, Hon-Chim; Tsang, Man-Yin; Li, Yiliang; Lam, Edmund Y.

2018-06-01

Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South China Sea. Compared to studies on similar datasets, but using supervised learning methods which are designed to make predictions based on sample training data, unsupervised learning methods require no a priori information and focus only on the input data. In this study, popular unsupervised learning methods including K-means, self-organizing maps, hierarchical clustering and random forest were coupled with different distance metrics to form exploratory data clusters. The resulting data clusters were externally validated with lithologic units and geologic time scales assigned to the datasets by conventional methods. Compact and connected data clusters displayed varying degrees of correspondence with existing classification by lithologic units and geologic time scales. K-means and self-organizing maps were observed to perform better with lithologic units while random forest corresponded best with geologic time scales. This study sets a pioneering example of how unsupervised machine learning methods can be used as an automatic processing tool for the increasingly high volume of scientific ocean drilling data.

Recent Geologic Mapping Results for the Polar Regions of Mars

NASA Technical Reports Server (NTRS)

tanaka, K. L.; Kolb, E. J.

2008-01-01

The polar regions of Mars include the densest data coverage for the planet because of the polar orbits of MGS, ODY, and MEX. Because the geology of the polar plateaus has been among the most dynamic on the planet in recent geologic time, the data enable the most detailed and complex geologic investigations of any regions on Mars, superseding previous, even recent, mapping efforts [e.g., 1-3]. Geologic mapping at regional and local scales is revealing that the stratigraphy and modificational histories of polar materials by various processes are highly complex at both poles. Here, we describe some of our recent results in polar geologic mapping and how they address the geologic processes involved and implications for polar climate history.

Porphyry copper deposit tract definition - A global analysis comparing geologic map scales

USGS Publications Warehouse

Raines, G.L.; Connors, K.A.; Chorlton, L.B.

2007-01-01

Geologic maps are a fundamental data source used to define mineral-resource potential tracts for the first step of a mineral resource assessment. Further, it is generally believed that the scale of the geologic map is a critical consideration. Previously published research has demonstrated that the U.S. Geological Survey porphyry tracts identified for the United States, which are based on 1:500,000-scale geology and larger scale data and published at 1:1,000,000 scale, can be approximated using a more generalized 1:2,500,000-scale geologic map. Comparison of the USGS porphyry tracts for the United States with weights-of-evidence models made using a 1:10,000,000-scale geologic map, which was made for petroleum applications, and a 1:35,000,000-scale geologic map, which was created as context for the distribution of porphyry deposits, demonstrates that, again, the USGS US porphyry tracts identified are similar to tracts defined on features from these small scale maps. In fact, the results using the 1:35,000,000-scale map show a slightly higher correlation with the USGS US tract definition, probably because the conceptual context for this small-scale map is more appropriate for porphyry tract definition than either of the other maps. This finding demonstrates that geologic maps are conceptual maps. The map information shown in each map is selected and generalized for the map to display the concepts deemed important for the map maker's purpose. Some geologic maps of small scale prove to be useful for regional mineral-resource tract definition, despite the decrease in spatial accuracy with decreasing scale. The utility of a particular geologic map for a particular application is critically dependent on the alignment of the intention of the map maker with the application. ?? International Association for Mathematical Geology 2007.

Using Relational Reasoning to Learn about Scientific Phenomena at Unfamiliar Scales

ERIC Educational Resources Information Center

Resnick, Ilyse; Davatzes, Alexandra; Newcombe, Nora S.; Shipley, Thomas F.

2016-01-01

Many scientific theories and discoveries involve reasoning about extreme scales, removed from human experience, such as time in geology, size in nanoscience. Thus, understanding scale is central to science, technology, engineering, and mathematics. Unfortunately, novices have trouble understanding and comparing sizes of unfamiliar large and small…

Using Relational Reasoning to Learn about Scientific Phenomena at Unfamiliar Scales

ERIC Educational Resources Information Center

Resnick, Ilyse; Davatzes, Alexandra; Newcombe, Nora S.; Shipley, Thomas F.

2017-01-01

Many scientific theories and discoveries involve reasoning about extreme scales, removed from human experience, such as time in geology and size in nanoscience. Thus, understanding scale is central to science, technology, engineering, and mathematics. Unfortunately, novices have trouble understanding and comparing sizes of unfamiliar large and…

GTSnext: towards a next generation of the geological time scale over the last 100 millions years. (Invited)

NASA Astrophysics Data System (ADS)

Kuiper, K.; Condon, D.; Hilgen, F.; Laskar, J.; Mezger, K.; Pälike, H.; Quidelleur, X.; Schaltegger, U.; Sprovieri, M.; Storey, M.; Wijbrans, J. R.

2009-12-01

The principal scientific objective of the Marie Curie Initial Trainings Network GTSnext is to establish the next generation standard Geological Time Scale with unprecedented accuracy, precision and resolution through integration and intercalibration of state-of-the-art numerical dating techniques. Such time scales underlie all fields in the Earth Sciences and their application will significantly contribute to a much enhanced understanding of Earth System evolution. During the last decade deep marine successions were successfully employed to establish an astronomical tuning for the entire Neogene, as incorporated in the standard Geological Time Scale (ATNTS2004). In GTSnext we aim to fine-tune this Neogene time scale, before it can reliably be used to accurately determine phase relations between astronomical forcing and climate response in the Neogene and possibly also the Oligocene. Radio-isotopic dating of late Neogene ash layers offers excellent opportunities for gaining insight into isotope systematics via their independent dating by astronomical tuning. An example of this synergy is the development of astronomically calibrated standards for 40Ar/39Ar geochronology. The cross-calibration between the different methods might also yield information on the fundamental problem of potential residence times in U/Pb dating. Extension of the astronomical time scale into the Paleogene seems limited to ~40 Ma due to the accuracy of the current astronomical solution. However, the 405 kyr eccentricity component is very stable permitting its use in time scale calibrations back to 250 Ma using only this frequency. This cycle is strong and well developed in Oligocene and even Eocene records. Phase relations between cyclic paleo-climate records and the 405 kyr eccentricity cycle are typically straightforward and unambiguous. Therefore, a first-order tuning to ~405 kyr eccentricity can only be revised by shifting the tuning with (multiples of) ~405 kyr. Isotopic age constraints of both U/Pb and 40Ar/39Ar will be used to anchor floating astronomical tunings, but absolute uncertainties in isotopic ages should be less than ± 200 kyr. The Cretaceous is famous for its remarkable cyclic successions of marine pelagic sediments which bear the unmistakable imprint of astronomical climate forcing. As a consequence floating astrochronologies which are based on number of cycles have been developed for significant portions of the Cretaceous, covering a number of geological stages. Unfortunately, such floating time scales provide us only with the duration of stages but not with their age. However, due to significant improvements in numerical astronomical solutions for the Solar System and in the accuracy of radio-isotopic dating we will try to establish a tuned time scale for the Late Cretaceous. Classical cyclic sections in Europe (e.g. Sopelana, Spain) will be used for the tuning, but lack ash beds. Therefore, radio-isotopic age constraints necessary for the tuning will come from ash beds in the Western Interior Basin in North America. Here we will present the first results of the GTSnext project.

Preliminary Integrated Geologic Map Databases for the United States: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island and Vermont

USGS Publications Warehouse

Nicholson, Suzanne W.; Dicken, Connie L.; Horton, John D.; Foose, Michael P.; Mueller, Julia A.L.; Hon, Rudi

2006-01-01

The rapid growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national scale digital geologic maps that have standardized information about geologic age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. Although two digital geologic maps (Schruben and others, 1994; Reed and Bush, 2004) of the United States currently exist, their scales (1:2,500,000 and 1:5,000,000) are too general for many regional applications. Most states have digital geologic maps at scales of about 1:500,000, but the databases are not comparably structured and, thus, it is difficult to use the digital database for more than one state at a time. This report describes the result for a seven state region of an effort by the U.S. Geological Survey to produce a series of integrated and standardized state geologic map databases that cover the entire United States. In 1997, the United States Geological Survey's Mineral Resources Program initiated the National Surveys and Analysis (NSA) Project to develop national digital databases. One primary activity of this project was to compile a national digital geologic map database, utilizing state geologic maps, to support studies in the range of 1:250,000- to 1:1,000,000-scale. To accomplish this, state databases were prepared using a common standard for the database structure, fields, attribution, and data dictionaries. For Alaska and Hawaii new state maps are being prepared and the preliminary work for Alaska is being released as a series of 1:250,000 scale quadrangle reports. This document provides background information and documentation for the integrated geologic map databases of this report. This report is one of a series of such reports releasing preliminary standardized geologic map databases for the United States. The data products of the project consist of two main parts, the spatial databases and a set of supplemental tables relating to geologic map units. The datasets serve as a data resource to generate a variety of stratigraphic, age, and lithologic maps. This documentation is divided into four main sections: (1) description of the set of data files provided in this report, (2) specifications of the spatial databases, (3) specifications of the supplemental tables, and (4) an appendix containing the data dictionaries used to populate some fields of the spatial database and supplemental tables.

Ways forward in quantifying data uncertainty in geological databases

NASA Astrophysics Data System (ADS)

Kint, Lars; Chademenos, Vasileios; De Mol, Robin; Kapel, Michel; Lagring, Ruth; Stafleu, Jan; van Heteren, Sytze; Van Lancker, Vera

2017-04-01

Issues of compatibility of geological data resulting from the merging of many different data sources and time periods may jeopardize harmonization of data products. Important progress has been made due to increasing data standardization, e.g., at a European scale through the SeaDataNet and Geo-Seas data management infrastructures. Common geological data standards are unambiguously defined, avoiding semantic overlap in geological data and associated metadata. Quality flagging is also applied increasingly, though ways in further propagating this information in data products is still at its infancy. For the Belgian and southern Netherlands part of the North Sea, databases are now rigorously re-analyzed in view of quantifying quality flags in terms of uncertainty to be propagated through a 3D voxel model of the subsurface (https://odnature.naturalsciences.be/tiles/). An approach is worked out to consistently account for differences in positioning, sampling gear, analysis procedures and vintage. The flag scaling is used in the interpolation process of geological data, but will also be used when visualizing the suitability of geological resources in a decision support system. Expert knowledge is systematically revisited as to avoid totally inappropriate use of the flag scaling process. The quality flagging is also important when communicating results to end-users. Therefore, an open data policy in combination with several processing tools will be at the heart of a new Belgian geological data portal as a platform for knowledge building (KB) and knowledge management (KM) serving the marine geoscience, the policy community and the public at large.

Tiny Molybdenites Tell Diffusion Tales

NASA Astrophysics Data System (ADS)

Stein, H. J.; Hannah, J. L.

2014-12-01

Diffusion invokes micron-scale exchange during crystal growth and dissolution in magma chambers on short time-scales. Fundamental to interpreting such data are assumptions on magma-fluid dynamics at all scales. Nevertheless, elemental diffusion profiles are used to estimate time scales for magma storage, eruption, and recharge. An underutilized timepiece to evaluate diffusion and 3D mobility of magmatic fluids is high-precision Re-Os dating of molybdenite. With spatially unique molybdenite samples from a young ore system (e.g., 1 Ma) and a double Os spike, analytical errors of 1-3 ka unambiguously separate events in time. Re-Os ages show that hydrous shallow magma chambers locally recharge and expel Cu-Mo-Au-silica as superimposed stockwork vein networks at time scales less than a few thousand years [1]. Re-Os ages provide diffusion rates controlled by a dynamic crystal mush, accumulation and expulsion of metalliferous fluid, and magma reorganization after explosive crystallization events. Importantly, this approach has broad application far from ore deposits. Here, we use Re-Os dating of molybdenite to assess time scales for generating and diffusing metals through the deep crust. To maximize opportunity for chemical diffusion, we use a continental-scale Sveconorwegian mylonite zone for the study area. A geologically constrained suite of molybdenite samples was acquired from quarry exposures. Molybdenite, previously unreported, is extremely scarce. Tiny but telling molybdenites include samples from like occurrences to assure geologic accuracy in Re-Os ages. Ages range from mid-Mesoproterozoic to mid-Neoproterozoic, and correspond to early metamorphic dehydration of a regionally widespread biotite-rich gneiss, localized melting of gneiss to form cm-m-scale K-feldspar ± quartz pods, development of vapor-rich, vuggy mm stringers that serve as volatile collection surfaces in felsic leucosomes, and low-angle (relative to foliation) cross-cutting cm-scale quartz veins. Re-Os ages and detailed geologic observation document a 200 m.y. history of metal liberation and diffusion through oxidation. [1] Stein, H.J. (2014) Dating and Tracing the History of Ore Formation, in Holland, H.D. & Turekian, K.K. (eds) Treatise on Geochemistry, 2nd Ed. 13: 87-118, Oxford: Elsevier.

Geologic map of the Chewelah 30' x 60' Quadrangle, Washington and Idaho

USGS Publications Warehouse

Miller, F.K.

2001-01-01

This data set maps and describes the geology of the Chewelah 30' X 60' quadrangle, Washington and Idaho. Created using Environmental Systems Research Institute's ARC/INFO software, the data base consists of the following items: (1) a map coverage containing geologic contacts and units, (2) a point coverage containing site-specific geologic structural data, (3) two coverages derived from 1:100,000 Digital Line Graphs (DLG); one of which represents topographic data, and the other, cultural data, (4) two line coverages that contain cross-section lines and unit-label leaders, respectively, and (5) attribute tables for geologic units (polygons), contacts (arcs), and site-specific data (points). In addition, the data set includes the following graphic and text products: (1) A PostScript graphic plot-file containing the geologic map, topography, cultural data, and two cross sections, and on a separate sheet, a Correlation of Map Units (CMU) diagram, an abbreviated Description of Map Units (DMU), modal diagrams for granitic rocks, an index map, a regional geologic and structure map, and a key for point and line symbols; (2) PDF files of the Readme text-file and expanded Description of Map Units (DMU), and (3) this metadata file. The geologic map database contains original U.S. Geological Survey data generated by detailed field observation and by interpretation of aerial photographs. The map was compiled from geologic maps of eight 1:48,000 15' quadrangle blocks, each of which was made by mosaicing and reducing the four constituent 7.5' quadrangles. These 15' quadrangle blocks were mapped chiefly at 1:24,000 scale, but the detail of the mapping was governed by the intention that it was to be compiled at 1:48,000 scale. The compilation at 1:100,000 scale entailed necessary simplification in some areas and combining of some geologic units. Overall, however, despite a greater than two times reduction in scale, most geologic detail found on the 1:48,000 maps is retained on the 1:100,000 map. Geologic contacts across boundaries of the eight constituent quadrangles required minor adjustments, but none significant at the final 1:100,000 scale. The geologic map was compiled on a base-stable cronoflex copy of the Chewelah 30' X 60' topographic base and then scribed. The scribe guide was used to make a 0.007 mil-thick blackline clear-film, which was scanned at 1200 DPI by Optronics Specialty Company, Northridge, California. This image was converted to vector and polygon GIS layers and minimally attributed by Optronics Specialty Company. Minor hand-digitized additions were made at the USGS. Lines, points, and polygons were subsequently edited at the USGS by using standard ARC/INFO commands. Digitizing and editing artifacts significant enough to display at a scale of 1:100,000 were corrected. Within the database, geologic contacts are represented as lines (arcs), geologic units as polygons, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum.

What is the Anthropocene?

USGS Publications Warehouse

Edwards, Lucy E.

2015-01-01

So far, however, the term “Anthropocene” has not been integrated into the official Geologic Time Scale, which geologists use to divide the past into named blocks based on the rock record. In 2016 or thereabouts, the International Commission on Stratigraphy—the scientific body that maintains the official Geologic Time Scale—will consider a proposal to formalize a definition of this term. It’s a decision that has both semantic and scientific implications and may have legal implications as well.

Phytoplankton Diversity and Geologically Relevant Carbon: Using metagenomics to determine phytoplankton biomarker production

NASA Astrophysics Data System (ADS)

Kodner, R. B.; Armbrust, E.

2008-12-01

Phytoplankton play an important role in the global carbon cycle, on short and long time scales. On long time scales, organic carbon, especially recalcitrant forms of biomass such as lipids, can be preserved and thus sequestered in sediments and rocks on geologic time scales. If the preserved lipids have some taxonomic specificity, they can be used as fossil biomarkers to characterize the community of organisms that contributed to ancient carbon sinks. Currently, it is not well understood how well the complex mixture of organic compounds preserved in geological carbon sinks represents the original community that produced those molecules or how the diversity of organism in a community is reflected in the lipid biomarkers they collectively synthesize. We have begun to investigate these questions by characterizing lipid biomarker production in modern phytoplankton communities with metagenomic data sets. Here we evaluate the information on community biomarker biosynthesis gathered from this type of data set using sterols as a case study. We have identified genes involved in sterol biosynthesis in a number of metagenomes and placed these genes in a phylogenetic context using a method designed to deal with short metagenomic sequences. The degree of taxonomic diversity of biomarker production measured with gene sequences can be more specific than lipid analysis alone.

Geologic map of the Bobs Flat Quadrangle, Eureka County, Nevada

USGS Publications Warehouse

Peters, Stephen G.

2003-01-01

Map Scale: 1:24,000 Map Type: colored geologic map A 1:24,000-scale, full-color geologic map of the Bobs Flat Quadrangle in Eureka County with one cross section and descriptions of 28 geologic units. Accompanying text describes the geologic history and structural geology of the quadrangle.

Volcanoes: observations and impact

USGS Publications Warehouse

Thurber, Clifford; Prejean, Stephanie G.

2012-01-01

Volcanoes are critical geologic hazards that challenge our ability to make long-term forecasts of their eruptive behaviors. They also have direct and indirect impacts on human lives and society. As is the case with many geologic phenomena, the time scales over which volcanoes evolve greatly exceed that of a human lifetime. On the other hand, the time scale over which a volcano can move from inactivity to eruption can be rather short: months, weeks, days, and even hours. Thus, scientific study and monitoring of volcanoes is essential to mitigate risk. There are thousands of volcanoes on Earth, and it is impractical to study and implement ground-based monitoring at them all. Fortunately, there are other effective means for volcano monitoring, including increasing capabilities for satellite-based technologies.

Geologic map of the Priest Rapids 1:100,000 quadrangle, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reidel, S.P.; Fecht, K.R.

1993-09-01

This map of the Priest Rapids 1:100,000-scale quadrangle, Washington, shows the geology of one of fifteen complete or partial 1:100,000-scale quadrangles that cover the southeast quadrant of Washington. Geologic maps of these quadrangles have been compiled by geologists with the Washington Division of Geology and Earth Resources (DGER) and Washington State University and are the principal data sources for a 1:250,000scale geologic map of the southeast quadrant of Washington, which is in preparation. Eleven of those quadrangles are being released as DGER open-file reports (listed below). The map of the Wenatchee quadrangle has been published by the US Geological Surveymore » (Tabor and others, 1982), and the Moses Lake (Gulick, 1990a), Ritzville (Gulick, 1990b), and Rosalia (Waggoner, 1990) quadrangles have already been released. The geology of the Priest Rapids quadrangle has not previously been compiled at 1:100,000 scale. Furthermore, this is the first 1:100,000 or smaller scale geologic map of the area to incorporate both bedrock and surficial geology. This map was compiled in 1992, using published and unpublished geologic maps as sources of data.« less

The role of topography on catchment‐scale water residence time

USGS Publications Warehouse

McGuire, K.J.; McDonnell, Jeffery J.; Weiler, M.; Kendall, C.; McGlynn, B.L.; Welker, J.M.; Seibert, J.

2005-01-01

The age, or residence time, of water is a fundamental descriptor of catchment hydrology, revealing information about the storage, flow pathways, and source of water in a single integrated measure. While there has been tremendous recent interest in residence time estimation to characterize watersheds, there are relatively few studies that have quantified residence time at the watershed scale, and fewer still that have extended those results beyond single catchments to larger landscape scales. We examined topographic controls on residence time for seven catchments (0.085–62.4 km2) that represent diverse geologic and geomorphic conditions in the western Cascade Mountains of Oregon. Our primary objective was to determine the dominant physical controls on catchment‐scale water residence time and specifically test the hypothesis that residence time is related to the size of the basin. Residence times were estimated by simple convolution models that described the transfer of precipitation isotopic composition to the stream network. We found that base flow mean residence times for exponential distributions ranged from 0.8 to 3.3 years. Mean residence time showed no correlation to basin area (r2 < 0.01) but instead was correlated (r2 = 0.91) to catchment terrain indices representing the flow path distance and flow path gradient to the stream network. These results illustrate that landscape organization (i.e., topography) rather than basin area controls catchment‐scale transport. Results from this study may provide a framework for describing scale‐invariant transport across climatic and geologic conditions, whereby the internal form and structure of the basin defines the first‐order control on base flow residence time.

Database for the geologic map of the Chelan 30-minute by 60-minute quadrangle, Washington (I-1661)

USGS Publications Warehouse

Tabor, R.W.; Frizzell, V.A.; Whetten, J.T.; Waitt, R.B.; Swanson, D.A.; Byerly, G.R.; Booth, D.B.; Hetherington, M.J.; Zartman, R.E.

2006-01-01

This digital map database has been prepared by R. W. Tabor from the published Geologic map of the Chelan 30-Minute Quadrangle, Washington. Together with the accompanying text files as PDF, it provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The authors mapped most of the bedrock geology at 1:100,000 scale, but compiled Quaternary units at 1:24,000 scale. The Quaternary contacts and structural data have been much simplified for the 1:100,000-scale map and database. The spatial resolution (scale) of the database is 1:100,000 or smaller. This database depicts the distribution of geologic materials and structures at a regional (1:100,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Database for the geologic map of the Snoqualmie Pass 30-minute by 60-minute quadrangle, Washington (I-2538)

USGS Publications Warehouse

Tabor, R.W.; Frizzell, V.A.; Booth, D.B.; Waitt, R.B.

2006-01-01

This digital map database has been prepared by R.W. Tabor from the published Geologic map of the Snoqualmie Pass 30' X 60' Quadrangle, Washington. Together with the accompanying text files as PDF, it provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The authors mapped most of the bedrock geology at 1:100,000 scale, but compiled Quaternary units at 1:24,000 scale. The Quaternary contacts and structural data have been much simplified for the 1:100,000-scale map and database. The spatial resolution (scale) of the database is 1:100,000 or smaller. This database depicts the distribution of geologic materials and structures at a regional (1:100,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Geologic Map of the Wenatchee 1:100,000 Quadrangle, Central Washington: A Digital Database

USGS Publications Warehouse

Tabor, R.W.; Waitt, R.B.; Frizzell, V.A.; Swanson, D.A.; Byerly, G.R.; Bentley, R.D.

2005-01-01

This digital map database has been prepared by R.W. Tabor from the published Geologic map of the Wenatchee 1:100,000 Quadrangle, Central Washington. Together with the accompanying text files as PDF, it provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The authors mapped most of the bedrock geology at 1:100,000 scale, but compiled Quaternary units at 1:24,000 scale. The Quaternary contacts and structural data have been much simplified for the 1:100,000-scale map and database. The spatial resolution (scale) of the database is 1:100,000 or smaller. This database depicts the distribution of geologic materials and structures at a regional (1:100,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

a Walk Through Earth's Time

NASA Astrophysics Data System (ADS)

Turrin, B. D.; Turrin, M.

2012-12-01

After "What is this rock?" the most common questions that is asked of Geologists is "How old is this rock/fossil?" For geologists considering ages back to millions of years is routine. Sorting and cataloguing events into temporal sequences is a natural tendency for all humans. In fact, it is an everyday activity for humans, i.e., keeping track of birthdays, anniversaries, appointments, meetings, AGU abstract deadlines etc… However, the time frames that are most familiar to the non scientist (seconds, minutes, hours, days, years) generally extend to only a few decades or at most centuries. Yet the vast length of time covered by Earth's history, 4.56 billion years, greatly exceeds these timeframes and thus is commonly referred to as "Deep Time". This is a challenging concept for most students to comprehend as it involves temporal and abstract thinking, yet it is key to their successful understanding of numerous geologic principles. We have developed an outdoor learning activity for general Introductory Earth Science courses that incorporates several scientific and geologic concepts such as: linear distance or stratigraphic thickness representing time, learning about major events in Earth's history and locating them in a scaled temporal framework, field mapping, abstract thinking, scaling and dimensional analysis, and the principles of radio isotopic dating. The only supplies needed are readily available in local hardware stores i.e. a 300 ft. surveyor's tape marked in feet, and tenths and hundredths of a foot, and the student's own introductory geology textbook. The exercise employs a variety of pedagogical learning modalities, including traditional lecture-based, the use of Art/Drawing, use of Visualization, Collaborative learning, and Kinesthetic and Experiential learning. Initially the students are exposed to the concept of "Deep Time" in a short conventional introductory lecture; this is followed by a 'field day'. Prior to the field exercise, students work with their textbook selecting events is Earth History that they find interesting. Using the textbook and online resources they then draw figures that represent these events. The drawing exercise reinforces the learning by having students visualize (imprinting an image) of these geologic events. Once the students have produced their drawings, the outdoor field exercise follows. Working collaboratively, the students measure and lay out a scaled linear model representing 4.56 billion years of geologic time. They then organize and place their drawings in the proper sequence on the temporal model that they have created. Once all the drawings are in place they are able to visualize the expanse of time in Earth's history. Through comparing results from a pre-test to those from a post-test we can show the gains in student understanding of Deep Time, a concept that is central to many of our geologic understandings.

Synthetic geology - Exploring the "what if?" in geology

NASA Astrophysics Data System (ADS)

Klump, J. F.; Robertson, J.

2015-12-01

The spatial and temporal extent of geological phenomena makes experiments in geology difficult to conduct, if not entirely impossible and collection of data is laborious and expensive - so expensive that most of the time we cannot test a hypothesis. The aim, in many cases, is to gather enough data to build a predictive geological model. Even in a mine, where data are abundant, a model remains incomplete because the information at the level of a blasting block is two orders of magnitude larger than the sample from a drill core, and we have to take measurement errors into account. So, what confidence can we have in a model based on sparse data, uncertainties and measurement error? Synthetic geology does not attempt to model the real world in terms of geological processes with all their uncertainties, rather it offers an artificial geological data source with fully known properties. On the basis of this artificial geology, we can simulate geological sampling by established or future technologies to study the resulting dataset. Conducting these experiments in silico removes the constraints of testing in the field or in production, and provides us with a known ground-truth against which the steps in a data analysis and integration workflow can be validated.Real-time simulation of data sources can be used to investigate crucial questions such as the potential information gain from future sensing capabilities, or from new sampling strategies, or the combination of both, and it enables us to test many "what if?" questions, both in geology and in data engineering. What would we be able to see if we could obtain data at higher resolution? How would real-time data analysis change sampling strategies? Does our data infrastructure handle many new real-time data streams? What feature engineering can be deducted for machine learning approaches? By providing a 'data sandbox' able to scale to realistic geological scenarios we hope to start answering some of these questions.

Geologic map of MTM -40252 and -40257 quadrangles, Reull Vallis region of Mars

USGS Publications Warehouse

Mest, Scott C.; Crown, David A.

2002-01-01

Mars Transverse Mercator (MTM) quadrangles -40252 and -40257 cover a portion of the highlands of Promethei Terra northeast of the Hellas basin. The map area consists of heavily cratered ancient highland materials of moderate to high relief, isolated knobs and massifs of rugged mountainous materials, extensive tracts of smooth and channeled plains, and other surficial deposits. Reull Vallis, an approximately 1,500 km-long outflow channel system, cuts through the southeast corner of the map area. Regional slopes are to the southwest, toward the Hellas basin, as indicated by Martian topographic maps and the orientations of channels along the northeast rim of the Hellas basin. The Martian highlands cover more than 60 percent of the planet's surface and are primarily in the southern hemisphere. Most of the highlands consist of rugged, densely cratered terrains believed to represent the final phase of heavy bombardment in the inner solar system about 4.0 billion years ago. Parts of the Martian highlands show evidence of extensive degradation and modification. The map area shows landforms created by numerous geologic processes, including tectonism, fluvial activity, and mass wasting. The occurrence of fluvial features, such as outflow channels and valley networks, has significant implications for past Martian conditions. Determining the geology of the highlands northeast of the Hellas basin provides a better understanding of the role and timing of volatile-driven activity in the evolution of the highlands. Photogeologic mapping at 1:500,000 scale from analysis of Viking Orbiter images complements geomorphic studies of Reull Vallis and other highland outflow systems, of drainage networks, and of highland debris aprons and regional geologic mapping studies of the highlands at the 1:2,000,000 scale and 1:1,000,000 scale. Crater size-frequency distributions have been compiled to constrain the relative ages of geologic units and determine the timing and extents of the observed geologic processes.

Geologic map of Detrital, Hualapai, and Sacramento Valleys and surrounding areas, northwest Arizona

USGS Publications Warehouse

Beard, L. Sue; Kennedy, Jeffrey; Truini, Margot; Felger, Tracey

2011-01-01

A 1:250,000-scale geologic map and report covering the Detrital, Hualapai, and Sacramento valleys in northwest Arizona is presented for the purpose of improving understanding of the geology and geohydrology of the basins beneath those valleys. The map was compiled from existing geologic mapping, augmented by digital photogeologic reconnaissance mapping. The most recent geologic map for the area, and the only digital one, is the 1:1,000,000-scale Geologic Map of Arizona. The larger scale map presented here includes significantly more detailed geology than the Geologic Map of Arizona in terms of accuracy of geologic unit contacts, number of faults, fault type, fault location, and details of Neogene and Quaternary deposits. Many sources were used to compile the geology; the accompanying geodatabase includes a source field in the polygon feature class that lists source references for polygon features. The citations for the source field are included in the reference section.

Exploring the Relationship between Students' Understanding of Conventional Time and Deep (Geologic) Time

NASA Astrophysics Data System (ADS)

Cheek, Kim A.

2013-07-01

Many geologic processes occur in the context of geologic or deep time. Students of all ages demonstrate difficulty grasping this fundamental concept which impacts their ability to acquire other geoscience concepts. A concept of deep time requires the ability to sequence events on an immense temporal scale (succession) and to judge the durations of geologic processes based on the rates at which they occur. The twin concepts of succession and duration are the same ideas that underlie a concept of conventional time. If deep time is an extension of conventional time and not qualitatively different from it, students should display similar reasoning patterns when dealing with analogous tasks over disparate temporal periods. Thirty-five US students aged 13-24 years participated in individual task-based interviews to ascertain how they thought about succession and duration in conventional and deep time. This is the first attempt to explore this relationship in the same study in over 30 years. Most students successfully completed temporal succession tasks, but there was greater variability in responses on duration tasks. Conventional time concepts appear to impact how students reason about deep time. The application of spatial reasoning to temporal tasks sometimes leads to correct responses but in other instances does not. Implications for future research and teaching strategies are discussed.

Impact phenomena as factors in the evolution of the Earth

NASA Technical Reports Server (NTRS)

Grieve, R. A. F.; Parmentier, E. M.

1984-01-01

It is estimated that 30 to 200 large impact basins could have been formed on the early Earth. These large impacts may have resulted in extensive volcanism and enhanced endogenic geologic activity over large areas. Initial modelling of the thermal and subsidence history of large terrestrial basins indicates that they created geologic and thermal anomalies which lasted for geologically significant times. The role of large-scale impact in the biological evolution of the Earth has been highlighted by the discovery of siderophile anomalies at the Cretaceous-Tertiary boundary and associated with North American microtektites. Although in neither case has an associated crater been identified, the observations are consistent with the deposition of projectile-contaminated high-speed ejecta from major impact events. Consideration of impact processes reveals a number of mechanisms by which large-scale impact may induce extinctions.

Geology and mineral resource assessment of the Venezuelan Guayana Shield at 1:500,000 scale; a digital representation of maps published by the U.S. Geological Survey

USGS Publications Warehouse

Schruben, Paul G.; Wynn, J.C.; Gray, Floyd; Cox, D.P.; Sterwart, J.H.; Brooks, W.E.

1997-01-01

This CD-ROM contains vector-based digital maps of the geology and resource assessment of the Venezuela Guayana Shield originally published as paper maps in 1993 in U. S. Geological Survey Bulletin 2062, at a scale of 1:1 million and revised in 1993-95 as separate maps at a scale of 1:500,000. Although the maps on this disc can be displayed at different scales, they are not intended to be used at any scale more detailed than 1:500,000.

Some ideas on the rock cycle: 1788-1988

NASA Astrophysics Data System (ADS)

Gregor, Bryan

1992-08-01

Hutton's procrastination on the subject of unconformities left his cyclic vision of geology in the shadows, while his success in demonstrating the igneous origin of granite led on to Classical Magmatism, a paradigm of secular evolution that reigned practically unchallenged for almost a century. When radiometric dating revealed the true extent of geologic time, a neo-Huttonian, cyclic view gained strength in Europe because of its ability to explain the salt content of the ocean and the sodium fixed in metamorphism of sediments to paragneiss, both of which had become embarrassing to the magmatists. Meantime, in North America, a quite independent movement was afoot to claim for sediments and cyclic processes their rightful place in geologic theory. It led to the acknowledgment that the cyclic and secular views of the Earth are complementary and not contradictory, and that geologic materials are recycled on varying time scales against a background of slow, secular evolution of the Earth.

CO{sub 2} Sequestration Capacity and Associated Aspects of the Most Promising Geologic Formations in the Rocky Mountain Region: Local-Scale Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laes, Denise; Eisinger, Chris; Morgan, Craig

2013-07-30

The purpose of this report is to provide a summary of individual local-­scale CCS site characterization studies conducted in Colorado, New Mexico and Utah. These site-­ specific characterization analyses were performed as part of the “Characterization of Most Promising Sequestration Formations in the Rocky Mountain Region” (RMCCS) project. The primary objective of these local-­scale analyses is to provide a basis for regional-­scale characterization efforts within each state. Specifically, limits on time and funding will typically inhibit CCS projects from conducting high-­ resolution characterization of a state-­sized region, but smaller (< 10,000 km{sup 2}) site analyses are usually possible, and suchmore » can provide insight regarding limiting factors for the regional-­scale geology. For the RMCCS project, the outcomes of these local-­scale studies provide a starting point for future local-­scale site characterization efforts in the Rocky Mountain region.« less

Supercomputer analysis of sedimentary basins.

PubMed

Bethke, C M; Altaner, S P; Harrison, W J; Upson, C

1988-01-15

Geological processes of fluid transport and chemical reaction in sedimentary basins have formed many of the earth's energy and mineral resources. These processes can be analyzed on natural time and distance scales with the use of supercomputers. Numerical experiments are presented that give insights to the factors controlling subsurface pressures, temperatures, and reactions; the origin of ores; and the distribution and quality of hydrocarbon reservoirs. The results show that numerical analysis combined with stratigraphic, sea level, and plate tectonic histories provides a powerful tool for studying the evolution of sedimentary basins over geologic time.

Database for the geologic map of the Sauk River 30-minute by 60-minute quadrangle, Washington (I-2592)

USGS Publications Warehouse

Tabor, R.W.; Booth, D.B.; Vance, J.A.; Ford, A.B.

2006-01-01

This digital map database has been prepared by R.W. Tabor from the published Geologic map of the Sauk River 30- by 60 Minute Quadrangle, Washington. Together with the accompanying text files as PDF, it provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The authors mapped most of the bedrock geology at 1:100,000 scale, but compiled most Quaternary units at 1:24,000 scale. The Quaternary contacts and structural data have been much simplified for the 1:100,000-scale map and database. The spatial resolution (scale) of the database is 1:100,000 or smaller. This database depicts the distribution of geologic materials and structures at a regional (1:100,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Time scale controversy: Accurate orbital calibration of the early Paleogene

NASA Astrophysics Data System (ADS)

Roehl, U.; Westerhold, T.; Laskar, J.

2012-12-01

Timing is crucial to understanding the causes and consequences of events in Earth history. The calibration of geological time relies heavily on the accuracy of radioisotopic and astronomical dating. Uncertainties in the computations of Earth's orbital parameters and in radioisotopic dating have hampered the construction of a reliable astronomically calibrated time scale beyond 40 Ma. Attempts to construct a robust astronomically tuned time scale for the early Paleogene by integrating radioisotopic and astronomical dating are only partially consistent. Here, using the new La2010 and La2011 orbital solutions, we present the first accurate astronomically calibrated time scale for the early Paleogene (47-65 Ma) uniquely based on astronomical tuning and thus independent of the radioisotopic determination of the Fish Canyon standard. Comparison with geological data confirms the stability of the new La2011 solution back to 54 Ma. Subsequent anchoring of floating chronologies to the La2011 solution using the very long eccentricity nodes provides an absolute age of 55.530 ± 0.05 Ma for the onset of the Paleocene/Eocene Thermal Maximum (PETM), 54.850 ± 0.05 Ma for the early Eocene ash -17, and 65.250 ± 0.06 Ma for the K/Pg boundary. The new astrochronology presented here indicates that the intercalibration and synchronization of U/Pb and 40Ar/39Ar radioisotopic geochronology is much more challenging than previously thought.

Time scale controversy: Accurate orbital calibration of the early Paleogene

NASA Astrophysics Data System (ADS)

Westerhold, Thomas; RöHl, Ursula; Laskar, Jacques

2012-06-01

Timing is crucial to understanding the causes and consequences of events in Earth history. The calibration of geological time relies heavily on the accuracy of radioisotopic and astronomical dating. Uncertainties in the computations of Earth's orbital parameters and in radioisotopic dating have hampered the construction of a reliable astronomically calibrated time scale beyond 40 Ma. Attempts to construct a robust astronomically tuned time scale for the early Paleogene by integrating radioisotopic and astronomical dating are only partially consistent. Here, using the new La2010 and La2011 orbital solutions, we present the first accurate astronomically calibrated time scale for the early Paleogene (47-65 Ma) uniquely based on astronomical tuning and thus independent of the radioisotopic determination of the Fish Canyon standard. Comparison with geological data confirms the stability of the new La2011 solution back to ˜54 Ma. Subsequent anchoring of floating chronologies to the La2011 solution using the very long eccentricity nodes provides an absolute age of 55.530 ± 0.05 Ma for the onset of the Paleocene/Eocene Thermal Maximum (PETM), 54.850 ± 0.05 Ma for the early Eocene ash -17, and 65.250 ± 0.06 Ma for the K/Pg boundary. The new astrochronology presented here indicates that the intercalibration and synchronization of U/Pb and 40Ar/39Ar radioisotopic geochronology is much more challenging than previously thought.

Global Geologic Map of Europa

NASA Technical Reports Server (NTRS)

Doggett, T.; Figueredo, P.; Greeley, R.; Hare, T.; Kolb, E.; Mullins, K.; Senske, D.; Tanaka, K.; Weiser, S.

2008-01-01

Europa, with its indications of a sub-ice ocean, is of keen interest to astrobiology and planetary geology. Knowledge of the global distribution and timing of Europan geologic units is a key step for the synthesis of data from the Galileo mission, and for the planning of future missions to the satellite. The first geologic map of Europa was produced at a hemisphere scale with low resolution Voyager data. Following the acquisition of higher resolution data by the Galileo mission, researchers have identified surface units and determined sequences of events in relatively small areas of Europa through geologic mapping using images at various resolutions acquired by Galileo's Solid State Imaging camera. These works provided a local to subregional perspective and employed different criteria for the determination and naming of units. Unified guidelines for the identification, mapping and naming of Europan geologic units were put forth by and employed in regional-to-hemispheric scale mapping which is now being expanded into a global geologic map. A global photomosaic of Galileo and Voyager data was used as a basemap for mapping in ArcGIS, following suggested methodology of all-stratigraphy for planetary mapping. The following units have been defined in global mapping and are listed in stratigraphic order from oldest to youngest: ridged plains material, Argadnel Regio unit, dark plains material, lineaments, disrupted plains material, lenticulated plains material and Chaos material.

Impact of Geological Changes on Regional and Global Economies

NASA Astrophysics Data System (ADS)

Tatiana, Skufina; Peter, Skuf'in; Vera, Samarina; Taisiya, Shatalova; Baranov, Sergey

2017-04-01

Periods of geological changes such as super continent cycle (300-500 million years), Wilson's cycles (300-900 million years), magmatic-tectonic cycle (150-200 million years), and cycles with smaller periods (22, 100, 1000 years) lead to a basic contradiction preventing forming methodology of the study of impact of geological changes on the global and regional economies. The reason of this contradiction is the differences of theoretical and methodological aspects of the Earth science and economics such as different time scales and accuracy of geological changes. At the present the geological models cannot provide accurate estimation of time and place where geological changes (strong earthquakes, volcanos) are expected. Places of feature (not next) catastrophic events are the only thing we have known. Thus, it is impossible to use the periodicity to estimate both geological changes and their consequences. Taking into accounts these factors we suggested a collection of concepts for estimating impact of possible geological changes on regional and global economies. We illustrated our approach by example of estimating impact of Tohoku earthquake and tsunami of March 2011 on regional and global economies. Based on this example we concluded that globalization processes increase an impact of geological changes on regional and global levels. The research is supported by Russian Foundation for Basic Research (Projects No. 16-06-00056, 16-32-00019, 16-05-00263A).

Geologic map of Chickasaw National Recreation Area, Murray County, Oklahoma

USGS Publications Warehouse

Blome, Charles D.; Lidke, David J.; Wahl, Ronald R.; Golab, James A.

2013-01-01

This 1:24,000-scale geologic map is a compilation of previous geologic maps and new geologic mapping of areas in and around Chickasaw National Recreation Area. The geologic map includes revisions of numerous unit contacts and faults and a number of previously “undifferentiated” rock units were subdivided in some areas. Numerous circular-shaped hills in and around Chickasaw National Recreation Area are probably the result of karst-related collapse and may represent the erosional remnants of large, exhumed sinkholes. Geospatial registration of existing, smaller scale (1:72,000- and 1:100,000-scale) geologic maps of the area and construction of an accurate Geographic Information System (GIS) database preceded 2 years of fieldwork wherein previously mapped geology (unit contacts and faults) was verified and new geologic mapping was carried out. The geologic map of Chickasaw National Recreation Area and this pamphlet include information pertaining to how the geologic units and structural features in the map area relate to the formation of the northern Arbuckle Mountains and its Arbuckle-Simpson aquifer. The development of an accurate geospatial GIS database and the use of a handheld computer in the field greatly increased both the accuracy and efficiency in producing the 1:24,000-scale geologic map.

"Tectonic Petrameter," An Alternative Method to Teaching the Geologic Time Scale

NASA Astrophysics Data System (ADS)

Posner, E. S.

2011-12-01

I have over a decade of experience as a performance poet and am now a graduate student in the geosciences. I have created a performance poem / play script, "Tectonic Petrameter," as an alternative method of teaching the geologic time scale. "The Archean came next and it was a blast. Tectonic plates were smaller and they moved pretty fast. In an enthusiastic flash of ash, volcanic islands smashed together." The use of rhyme and rhythm presents a different and interdisciplinary approach to teaching Earth history that appeals to a wide range of learning styles and makes science fun, while clearly describing important concepts in geology and events in Earth history. "Now it's time to get down with the Coal Swamp Stomp! Tap your feet to the beat of the formation of peat like a plant plantation soaking up the bright heat." "Tectonic Petrameter" by itself is an illustrated spoken-word poem that leads audiences from all levels of scientific background on an excitingly educational journey through geologic time. I will perform my 10-minute memorized poem and present results from my ongoing study to assess the effectiveness of "Tectonic Petrameter" as a teaching tool in K-12 and introductory undergraduate classroom curricula. I propose that using "Tectonic Petrameter" as a performance piece and theatrical play script in K-12 and introductory undergraduate classrooms, as well as in broader community venues, may be an avenue for breaking down barriers related to teaching about Earth's long and complex history. Digital copies of "Tectonic Petrameter" will be made available to interested parties.

Earth System Stability Through Geologic Time

NASA Astrophysics Data System (ADS)

Rothman, D.; Bowring, S. A.

2015-12-01

Five times in the past 500 million years, mass extinctions haveresulted in the loss of greater than three-fourths of living species.Each of these events is associated with significant environmentalchange recorded in the carbon-isotopic composition of sedimentaryrocks. There are also many such environmental events in the geologicrecord that are not associated with mass extinctions. What makes themdifferent? Two factors appear important: the size of theenvironmental perturbation, and the time scale over which it occurs.We show that the natural perturbations of Earth's carbon cycle during thepast 500 million years exhibit a characteristic rate of change overtwo orders of magnitude in time scale. This characteristic rate isconsistent with the maximum rate that limits quasistatic (i.e., nearsteady-state) evolution of the carbon cycle. We identify this rate withmarginal stability, and show that mass extinctions occur on the fast,unstable side of the stability boundary. These results suggest thatthe great extinction events of the geologic past, and potentially a"sixth extinction" associated with modern environmental change, arecharacterized by common mechanisms of instability.

Geologic Map of the Yukon-Koyukuk Basin, Alaska

USGS Publications Warehouse

Patton, William W.; Wilson, Frederic H.; Labay, Keith A.; Shew, Nora B.

2009-01-01

This map and accompanying digital files represent part of a systematic effort to release geologic data for the United States in a uniform manner. All the geologic data in this series will be published as parts of the U.S. Geological Survey Data Series. The geologic data in this series have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale field mapping. The data are presented for use at a nominal scale of 1:500,000, although individual datasets may contain data suitable for use at larger scales. The metadata associated with each release will provide more detailed information on sources and appropriate scales for use. Associated attribute databases accompany the spatial database of the geology and are uniformly structured for ease in developing regional- and national-scale maps. The 1:500,000-scale geologic map of the Yukon-Koyukuk Basin, Alaska, covers more than 200,000 square kilometers of western Alaska or nearly 15 percent of the total land area of the state. It stretches from the Brooks Range on the north to the Kuskokwim River and lower reaches of the Yukon River on the south and from Kotzebue Sound, Seward Peninsula, and Norton Sound on the west to the Yukon-Tanana Uplands and Tanana-Kuskokwim Lowlands on the east. It includes not only the northern and central part of the basin, but also the lands that border the basin. The area is characterized by isolated clusters of hills and low mountain ranges separated by broad alluviated interior and coastal lowlands. Most of the lowlands, except those bordering Kotzebue Sound and Norton Sound, support a heavy vegetation cover. Exposures of bedrock are generally limited to rubble-strewn ridgetops and to cutbanks along the rivers. The map of the Yukon-Koyukuk Basin was prepared largely from geologic field data collected between 1953 and 1988 by the U.S. Geological Survey and published as 1:250,000-scale geologic quadrangle maps. Additional data for parts of the Wiseman, Ruby, Medfra, and Ophir quadrangles came from 1:63,360-scale quadrangle maps published by the Alaska Division of Geological and Geophysical Surveys. The map also incorporates some unpublished field data for the Ruby quadrangle collected by R.M. Chapman between 1944 and 1977 and for parts of the Tanana, Bettles, Norton Bay, and Candle quadrangles collected by W.W. Patton, Jr. and others between 1954 and 1985. Sources of geologic map data for each of the eighteen 1:250,000-scale quadrangles used in compiling this 1:500,000-scale map of the Yukon-Koyukuk Basin as well as sources of general geologic information pertaining to the entire map area are provided in the 'Sources of Information' section.

Fast laboratory-based micro-computed tomography for pore-scale research: Illustrative experiments and perspectives on the future

NASA Astrophysics Data System (ADS)

Bultreys, Tom; Boone, Marijn A.; Boone, Matthieu N.; De Schryver, Thomas; Masschaele, Bert; Van Hoorebeke, Luc; Cnudde, Veerle

2016-09-01

Over the past decade, the wide-spread implementation of laboratory-based X-ray micro-computed tomography (micro-CT) scanners has revolutionized both the experimental and numerical research on pore-scale transport in geological materials. The availability of these scanners has opened up the possibility to image a rock's pore space in 3D almost routinely to many researchers. While challenges do persist in this field, we treat the next frontier in laboratory-based micro-CT scanning: in-situ, time-resolved imaging of dynamic processes. Extremely fast (even sub-second) micro-CT imaging has become possible at synchrotron facilities over the last few years, however, the restricted accessibility of synchrotrons limits the amount of experiments which can be performed. The much smaller X-ray flux in laboratory-based systems bounds the time resolution which can be attained at these facilities. Nevertheless, progress is being made to improve the quality of measurements performed on the sub-minute time scale. We illustrate this by presenting cutting-edge pore scale experiments visualizing two-phase flow and solute transport in real-time with a lab-based environmental micro-CT set-up. To outline the current state of this young field and its relevance to pore-scale transport research, we critically examine its current bottlenecks and their possible solutions, both on the hardware and the software level. Further developments in laboratory-based, time-resolved imaging could prove greatly beneficial to our understanding of transport behavior in geological materials and to the improvement of pore-scale modeling by providing valuable validation.

Monitoring CO2 invasion processes at the pore scale using geological labs on chip.

PubMed

Morais, S; Liu, N; Diouf, A; Bernard, D; Lecoutre, C; Garrabos, Y; Marre, S

2016-09-21

In order to investigate at the pore scale the mechanisms involved during CO2 injection in a water saturated pore network, a series of displacement experiments is reported using high pressure micromodels (geological labs on chip - GLoCs) working under real geological conditions (25 < T (°C) < 75 and 4.5 < p (MPa) < 8). The experiments were focused on the influence of three experimental parameters: (i) the p, T conditions, (ii) the injection flow rates and (iii) the pore network characteristics. By using on-chip optical characterization and imaging approaches, the CO2 saturation curves as a function of either time or the number of pore volume injected were determined. Three main mechanisms were observed during CO2 injection, namely, invasion, percolation and drying, which are discussed in this paper. Interestingly, besides conventional mechanisms, two counterintuitive situations were observed during the invasion and drying processes.

Evidence for a common scale O(0.1) m that controls seabed scattering and reverberation in shallow water.

PubMed

Holland, Charles W

2012-10-01

Analysis of the spectral content of long-range reverberation yields two observations. First, there is a remarkably similar scale, O(0.1) m, between three diverse continental shelf regions. This is surprising given the complexity and diversity of geologic processes. Second, there is strong evidence that the scale is associated with heterogeneities within the sediment. Thus, sediment volume scattering, not interface scattering, controls long-range reverberation from a few hundred hertz to several kilohertz. This is also unexpected given that at long ranges the vertical grazing angles are less than the critical angle, and hence the penetration of the acoustic field into the sub-bottom is expected to be modest. The consistency of the scale, O(0.1) m, suggests an underlying feature or mechanism that is consistent across many ostensibly diverse geological settings. Neither the feature nor mechanism is known at this time.

Where in Time?

ERIC Educational Resources Information Center

Pecore, John; Sacks, David

2005-01-01

In this article, the authors describe an activity developed to assist students with constructing their own understanding of Earth's history and provide questions to help teach the geologic time scale. The lesson is aligned to the following National Science Education Standards: Science as Inquiry, Earth's History, and Nature of Science. While…

Geologic map of the Richland 1:100,000 quadrangle, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reidel, S.P.; Fecht, K.R.

1993-09-01

This map of the Richland 1:100,000-scale quadrangle, Washington, shows the geology of one of fifteen complete or partial 1:100,000-scale quadrangles that cover the southeast quadrant of Washington. Geologic maps of these quadrangles have been compiled by geologists with the Washington Division of Geology and Earth Resources (DGER) and Washington State University and are the principal data sources for a 1:250,000-scale geologic map of the southeast quadrant of Washington, which is in preparation. Eleven of these quadrangles are being released as DGER open-file reports. The map of the Wenatchee quadrangle has been published by the US Geological Survey, and the Mosesmore » Lake, Ritzville quadrangles have already been released.« less

Field reconnaissance geologic mapping of the Columbia Hills, Mars, based on Mars Exploration Rover Spirit and MRO HiRISE observations

NASA Astrophysics Data System (ADS)

Crumpler, L. S.; Arvidson, R. E.; Squyres, S. W.; McCoy, T.; Yingst, A.; Ruff, S.; Farrand, W.; McSween, Y.; Powell, M.; Ming, D. W.; Morris, R. V.; Bell, J. F., III; Grant, J.; Greeley, R.; DesMarais, D.; Schmidt, M.; Cabrol, N. A.; Haldemann, A.; Lewis, Kevin W.; Wang, A. E.; Schröder, C.; Blaney, D.; Cohen, B.; Yen, A.; Farmer, J.; Gellert, R.; Guinness, E. A.; Herkenhoff, K. E.; Johnson, J. R.; Klingelhöfer, G.; McEwen, A.; Rice, J. W., Jr.; Rice, M.; deSouza, P.; Hurowitz, J.

2011-07-01

Chemical, mineralogic, and lithologic ground truth was acquired for the first time on Mars in terrain units mapped using orbital Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (MRO HiRISE) image data. Examination of several dozen outcrops shows that Mars is geologically complex at meter length scales, the record of its geologic history is well exposed, stratigraphic units may be identified and correlated across significant areas on the ground, and outcrops and geologic relationships between materials may be analyzed with techniques commonly employed in terrestrial field geology. Despite their burial during the course of Martian geologic time by widespread epiclastic materials, mobile fines, and fall deposits, the selective exhumation of deep and well-preserved geologic units has exposed undisturbed outcrops, stratigraphic sections, and structural information much as they are preserved and exposed on Earth. A rich geologic record awaits skilled future field investigators on Mars. The correlation of ground observations and orbital images enables construction of a corresponding geologic reconnaissance map. Most of the outcrops visited are interpreted to be pyroclastic, impactite, and epiclastic deposits overlying an unexposed substrate, probably related to a modified Gusev crater central peak. Fluids have altered chemistry and mineralogy of these protoliths in degrees that vary substantially within the same map unit. Examination of the rocks exposed above and below the major unconformity between the plains lavas and the Columbia Hills directly confirms the general conclusion from remote sensing in previous studies over past years that the early history of Mars was a time of more intense deposition and modification of the surface. Although the availability of fluids and the chemical and mineral activity declined from this early period, significant later volcanism and fluid convection enabled additional, if localized, chemical activity.

Field Reconnaissance Geologic Mapping of the Columbia Hills, Mars: Results from MER Spirit and MRO HiRISE Observations

USGS Publications Warehouse

Crumpler, L.S.; Arvidson, R. E.; Squyres, S. W.; McCoy, T.; Yingst, A.; Ruff, S.; Farrand, W.; McSween, Y.; Powell, M.; Ming, D. W.; Morris, R.V.; Bell, J.F.; Grant, J.; Greeley, R.; DesMarais, D.; Schmidt, M.; Cabrol, N.A.; Haldemann, A.; Lewis, Kevin W.; Wang, A.E.; Schroder, C.; Blaney, D.; Cohen, B.; Yen, A.; Farmer, J.; Gellert, Ralf; Guinness, E.A.; Herkenhoff, K. E.; Johnson, J. R.; Klingelhofer, G.; McEwen, A.; Rice, J. W.; Rice, M.; deSouza, P.; Hurowitz, J.

2011-01-01

Chemical, mineralogic, and lithologic ground truth was acquired for the first time on Mars in terrain units mapped using orbital Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (MRO HiRISE) image data. Examination of several dozen outcrops shows that Mars is geologically complex at meter length scales, the record of its geologic history is well exposed, stratigraphic units may be identified and correlated across significant areas on the ground, and outcrops and geologic relationships between materials may be analyzed with techniques commonly employed in terrestrial field geology. Despite their burial during the course of Martian geologic time by widespread epiclastic materials, mobile fines, and fall deposits, the selective exhumation of deep and well-preserved geologic units has exposed undisturbed outcrops, stratigraphic sections, and structural information much as they are preserved and exposed on Earth. A rich geologic record awaits skilled future field investigators on Mars. The correlation of ground observations and orbital images enables construction of a corresponding geologic reconnaissance map. Most of the outcrops visited are interpreted to be pyroclastic, impactite, and epiclastic deposits overlying an unexposed substrate, probably related to a modified Gusev crater central peak. Fluids have altered chemistry and mineralogy of these protoliths in degrees that vary substantially within the same map unit. Examination of the rocks exposed above and below the major unconformity between the plains lavas and the Columbia Hills directly confirms the general conclusion from remote sensing in previous studies over past years that the early history of Mars was a time of more intense deposition and modification of the surface. Although the availability of fluids and the chemical and mineral activity declined from this early period, significant later volcanism and fluid convection enabled additional, if localized, chemical activity.

Enhancement of a Virtual Geology Field Guide of Georgia Initiative Using Gigapan© and ArcGIS Online's Story Map

NASA Astrophysics Data System (ADS)

Mobasher, K.; Turk, H. J.; Witherspoon, W.; Tate, L.; Hoynes, J.

2015-12-01

A GIS geology geodatabase of Georgia was developed using ArcGIS 10.2. The geodatabase for each physiographic provinces of Georgia contains fields designed to store information regarding geologic features. Using ArcGIS online, the virtual field guide is created which provides an interactive learning experience for students to allow in real time photography, description, mapping and sharing their observations with the instructor and peers. Gigapan© facilitates visualizing geologic features at different scales with high resolutions and in their larger surrounding context. The classroom applications of the Gigapan© are limitless when teaching students the entire range of geologic structures from showcasing crystalline structures of minerals to understanding the geological processes responsible for formation of an entire mountain range. The addition of the Story Map enhances the virtual experience when you want to present a geo-located story point narrative featuring images or videos. The virtual field component and supplementary Gigapan© imagery coupled with Story Map added significantly to the detailed realism of virtual field guide further allowing students to more fully understand geological concepts at various scales. These technologies peaked students interest and facilitated their learning and preparation to function more effectively in the geosciences by developing better observations and new skills. These technologies facilitated increased student engagement in the geosciences by sharing, enhancing and transferring lecture information to actual field knowledge and experiences. This enhanced interactive learning experience not only begins to allow students to understand and recognize geologic features in the field but also increased their collaboration, enthusiasm and interest in the discipline. The increased interest and collaboration occurred as students assisted in populating a geologic geodatabase of Georgia.

Comparison of SLAR images and small-scale, low-sun aerial photographs.

NASA Technical Reports Server (NTRS)

Clark, M. M.

1971-01-01

A comparison of side-looking airborne radar (SLAR) images and black and white aerial photos of similar scale and illumination of an area in the Mojave Desert of California shows that aerial photos yield far more information about geology than do SLAR images because of greater resolution, tonal range, and geometric fidelity, and easier use in stereo. Nevertheless, radar can differentiate some materials or surfaces that aerial photos cannot; thus, they should be considered as complementary, rather than competing tools in geologic investigations. The most significant advantage of SLAR, however, is its freedom from the stringent conditions of weather, date, and time that are required by small-scale aerial photos taken with a specified direction and angle of illumination. Indeed, in low latitudes, SLAR is the only way to obtain small-scale images with low illumination from certain directions; moreover, in areas of nearly continuous cloudiness, radar may be the only practical source of small-scale images.

Hydrology of the Helena area bedrock, west-central Montana, 1993-98; with a section on geologic setting and a generalized bedrock geologic map

USGS Publications Warehouse

Thamke, Joanna N.; Reynolds, Mitchell W.

2000-01-01

The Generalized Bedrock Geologic Map of the Helena Area, West-Central Montana (plate 1 in the report) provides an intermediate-scale overview of bedrock in the Helena area. The geologic map has been compiled at a scale of 1:100,000 from the most widely available sources of geologic map information (see index to geologic mapping on pl. 1). That information has been updated by M.W. Reynolds for this report with more recent geologic mapping and field revision of published maps. All well locations and all bedrock units penetrated during drilling have been confirmed on geologic maps at the largest scale available. Source geologic maps are all at scales larger than 1:100,000 scale. Care has been taken to ensure accurate representation of the original geology at the compilation scale. However, positional accuracy of some features might be somewhat diminished at the smaller scale of the base map when compared with the original data source. Also, line thicknesses for contacts and faults necessarily assume a greater width, relative to the real geologic feature, at the scale of the generalized map than on any original map. The map is not intended for large-scale, site-specific detailed planning. Bedrock units throughout the Helena area are generally covered by young surficial deposits such as alluvium, colluvium, glacial debris, or windblown sediment. Thickness of such deposits varies from veneers through which the underlying bedrock is clearly discernible to major thicknesses that conceal all underlying bedrock and structure. Boundaries of major accumulations of surficial deposits are attributed separately from bedrock contacts. These boundaries should not be considered precise at the map scale or at larger scales. Boundaries shown may be less accurate positionally than bedrock contacts and faults because (1) surficial deposits commonly thin to a knife edge; (2) different mappers will interpret the edge differently when drawing a boundary; or (3) the original geologic map maker was concerned principally with bedrock units and structure and thus overlooked, or did not originally map as consistently, some surficial deposits. Veneers of surficial sediment, when saturated, can be local sources of recharge to underlying bedrock. Use of the generalized map to define their distribution does not substitute for site specific mapping of such deposits. Specific knowledge is needed to determine the water-bearing properties of the geologic units at and surrounding a site because the units, including the igneous and metamorphic rocks, have internal differences in stratigraphy, composition, mineralogy and grain size or crystallinity. These differences, together with structural imprints such as faults, folds, and the spacing, orientation, degree of openness of fractures, and extent and type of mineral filling in fractures and faults, all affect the ability of rocks to store and transmit water.

Cross-Scale Modelling of Subduction from Minute to Million of Years Time Scale

NASA Astrophysics Data System (ADS)

Sobolev, S. V.; Muldashev, I. A.

2015-12-01

Subduction is an essentially multi-scale process with time-scales spanning from geological to earthquake scale with the seismic cycle in-between. Modelling of such process constitutes one of the largest challenges in geodynamic modelling today.Here we present a cross-scale thermomechanical model capable of simulating the entire subduction process from rupture (1 min) to geological time (millions of years) that employs elasticity, mineral-physics-constrained non-linear transient viscous rheology and rate-and-state friction plasticity. The model generates spontaneous earthquake sequences. The adaptive time-step algorithm recognizes moment of instability and drops the integration time step to its minimum value of 40 sec during the earthquake. The time step is then gradually increased to its maximal value of 5 yr, following decreasing displacement rates during the postseismic relaxation. Efficient implementation of numerical techniques allows long-term simulations with total time of millions of years. This technique allows to follow in details deformation process during the entire seismic cycle and multiple seismic cycles. We observe various deformation patterns during modelled seismic cycle that are consistent with surface GPS observations and demonstrate that, contrary to the conventional ideas, the postseismic deformation may be controlled by viscoelastic relaxation in the mantle wedge, starting within only a few hours after the great (M>9) earthquakes. Interestingly, in our model an average slip velocity at the fault closely follows hyperbolic decay law. In natural observations, such deformation is interpreted as an afterslip, while in our model it is caused by the viscoelastic relaxation of mantle wedge with viscosity strongly varying with time. We demonstrate that our results are consistent with the postseismic surface displacement after the Great Tohoku Earthquake for the day-to-year time range. We will also present results of the modeling of deformation of the upper plate during multiple earthquake cycles at times of hundred thousand and million years and discuss effect of great earthquakes in changing long-term stress field in the upper plate.

Time Scale Optimization and the Hunt for Astronomical Cycles in Deep Time Strata

NASA Astrophysics Data System (ADS)

Meyers, Stephen R.

2016-04-01

A valuable attribute of astrochronology is the direct link between chronometer and climate change, providing a remarkable opportunity to constrain the evolution of the surficial Earth System. Consequently, the hunt for astronomical cycles in strata has spurred the development of a rich conceptual framework for climatic/oceanographic change, and has allowed exploration of the geologic record with unprecedented temporal resolution. Accompanying these successes, however, has been a persistent skepticism about appropriate astrochronologic testing and circular reasoning: how does one reliably test for astronomical cycles in stratigraphic data, especially when time is poorly constrained? From this perspective, it would seem that the merits and promise of astrochronology (e.g., a geologic time scale measured in ≤400 kyr increments) also serves as its Achilles heel, if the confirmation of such short rhythms defies rigorous statistical testing. To address these statistical challenges in astrochronologic testing, a new approach has been developed that (1) explicitly evaluates time scale uncertainty, (2) is resilient to common problems associated with spectrum confidence level assessment and 'multiple testing', and (3) achieves high statistical power under a wide range of conditions (it can identify astronomical cycles when present in data). Designated TimeOpt (for "time scale optimization"; Meyers 2015), the method employs a probabilistic linear regression model framework to investigate amplitude modulation and frequency ratios (bundling) in stratigraphic data, while simultaneously determining the optimal time scale. This presentation will review the TimeOpt method, and demonstrate how the flexible statistical framework can be further extended to evaluate (and optimize upon) complex sedimentation rate models, enhancing the statistical power of the approach, and addressing the challenge of unsteady sedimentation. Meyers, S. R. (2015), The evaluation of eccentricity-related amplitude modulation and bundling in paleoclimate data: An inverse approach for astrochronologic testing and time scale optimization, Paleoceanography, 30, doi:10.1002/ 2015PA002850.

Application of remote sensor data to geologic analysis of the Bonanza Test Site Colorado

NASA Technical Reports Server (NTRS)

Lee, K. (Compiler)

1973-01-01

A geologic map of the Bonanza Test Site is nearing completion. Using published large scale geologic maps from various sources, the geology of the area is being compiled on a base scaled at 1:250,000. Sources of previously published geologic mapping include: (1) USGS Bulletins; (2) professional papers and geologic quadrangle maps; (3) Bureau of Mines reports; (4) Colorado School of Mines quarterlies; and (5) Rocky Mountain Association of Geologist Guidebooks. This compilation will be used to evaluate ERTS, Skylab, and remote sensing underflight data.

Database for the geologic map of the Mount Baker 30- by 60-minute quadrangle, Washington (I-2660)

USGS Publications Warehouse

Tabor, R.W.; Haugerud, R.A.; Hildreth, Wes; Brown, E.H.

2006-01-01

This digital map database has been prepared by R.W. Tabor from the published Geologic map of the Mount Baker 30- by 60-Minute Quadrangle, Washington. Together with the accompanying text files as PDF, it provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The authors mapped most of the geology at 1:100,000. The Quaternary contacts and structural data have been much simplified for the 1:100,000-scale map and database. The spatial resolution (scale) of the database is 1:100,000 or smaller. This database depicts the distribution of geologic materials and structures at a regional (1:100,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Preliminary Geologic Map of the North-Central Part of the Alamosa 30' x 60' Quadrangle, Alamosa, Conejos and Costilla Counties, Colorado

USGS Publications Warehouse

Machette, Michael N.; Thompson, Ren A.; Brandt, Theodore R.

2008-01-01

This geologic map presents new polygon (geologic map unit contacts) and line (terrace and lacustrine spit/barrier bar) vector data for a map comprised of four 7.5' quadrangles in the north-central part of the Alamosa, Colorado, 30' x 60' quadrangle. The quadrangles include Baldy, Blanca, Blanca SE, and Lasauses. The map database, compiled at 1:50,000 scale from new 1:24,000-scale mapping, provides geologic coverage of an area of current hydrogeologic, tectonic, and stratigraphic interest. The mapped area is located primarily in Costilla County, but contains portions of Alamosa and Conejos Counties, and includes the town of Blanca in its northeastern part. The map area is mainly underlain by surficial geologic materials (fluvial and lacustrine deposits, and eolian sand), but Tertiary volcanic and volcaniclastic rocks crop out in the San Luis Hills, which are in the central and southern parts of the mapped area. The surficial geology of this area has never been mapped at any scale greater than 1:250,000 (broad reconnaissance), so this new map provides important data for ground-water assessments, engineering geology, and the Quaternary geologic history of the San Luis Basin. Newly discovered shoreline deposits are of particular interest (sands and gravels) that are associated with the high-water stand of Lake Alamosa, a Pliocene to middle Pleistocene lake that occupied the San Luis basin prior to its overflow and cutting of a river gorge through the San Luis Hills. After the lake drained, the Rio Grande system included Colorado drainages for the first time since the Miocene (>5.3 Ma). In addition, Servilleta Basalt, which forms the Basaltic Hills on the east margin of the map area, is dated at 3.79+or-0.17 Ma, consistent with its general age range of 3.67-4.84 Ma. This map provides new geologic information for better understanding ground-water flow paths in and adjacent to the Rio Grande system. The map abuts U.S. Geological Survey Open File Report 2005-1392 (a map of the northwestern part of the Alamosa 30' x 60' quadrangle map) to the west and U.S. Geological Survey Scientific Investigations Map 2965 (Fort Garland 7.5' quadrangle) to the east.

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States

USGS Publications Warehouse

Horton, John D.; San Juan, Carma A.; Stoeser, Douglas B.

2017-06-30

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (https://doi. org/10.5066/F7WH2N65) represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies and assessments, such as those that provide geochemistry, remote sensing, or geophysical data. The SGMC is a compilation of the individual U.S. Geological Survey releases of the Preliminary Integrated Geologic Map Databases for the United States. The SGMC geodatabase also contains updated data for seven States and seven entirely new State geologic maps that have been added since the preliminary databases were published. Numerous errors have been corrected and enhancements added to the preliminary datasets using thorough quality assurance/quality control procedures. The SGMC is not a truly integrated geologic map database because geologic units have not been reconciled across State boundaries. However, the geologic data contained in each State geologic map have been standardized to allow spatial analyses of lithology, age, and stratigraphy at a national scale.

Fractional Progress Toward Understanding the Fractional Diffusion Limit: The Electromagnetic Response of Spatially Correlated Geomaterials

NASA Astrophysics Data System (ADS)

Weiss, C. J.; Beskardes, G. D.; Everett, M. E.

2016-12-01

In this presentation we review the observational evidence for anomalous electromagnetic diffusion in near-surface geophysical exploration and how such evidence is consistent with a detailed, spatially-correlated geologic medium. To date, the inference of multi-scale geologic correlation is drawn from two independent methods of data analysis. The first of which is analogous to seismic move-out, where the arrival time of an electromagnetic pulse is plotted as a function of transmitter/receiver separation. The "anomalous" diffusion is evident by the fractional-order power law behavior of these arrival times, with an exponent value between unity (pure diffusion) and 2 (lossless wave propagation). The second line of evidence comes from spectral analysis of small-scale fluctuations in electromagnetic profile data which cannot be explained in terms of instrument, user or random error. Rather, the power-law behavior of the spectral content of these signals (i.e., power versus wavenumber) and their increments reveals them to lie in a class of signals with correlations over multiple length scales, a class of signals known formally as fractional Brownian motion. Numerical results over simulated geology with correlated electrical texture - representative of, for example, fractures, sedimentary bedding or metamorphic lineation - are consistent with the (albeit limited, but growing) observational data, suggesting a possible mechanism and modeling approach for a more realistic geology. Furthermore, we show how similar simulated results can arise from a modeling approach where geologic texture is economically captured by a modified diffusion equation containing exotic, but manageable, fractional derivatives. These derivatives arise physically from the generalized convolutional form for the electromagnetic constitutive laws and thus have merit beyond mere mathematical convenience. In short, we are zeroing in on the anomalous, fractional diffusion limit from two converging directions: a zooming down of the macroscopic (fractional derivative) view; and, a heuristic homogenization of the atomistic (brute force discretization) view.

Lunar Geologic Mapping: A Preliminary Map of a Portion of the LQ-10 ("Marius") Quadrangle

NASA Technical Reports Server (NTRS)

Gregg, T. K. P.; Yingst, R. A.

2009-01-01

Since the first lunar mapping program ended in the 1970s, new topographical, multispectral, elemental and albedo imaging datasets have become available (e.g., Clementine, Lunar Prospector, Galileo). Lunar science has also advanced within the intervening time period. A new systematic lunar geologic mapping effort endeavors to build on the success of earlier mapping programs by fully integrating the many disparate datasets using GIS software and bringing to bear the most current understanding of lunar geologic history. As part of this program, we report on a 1:2,500,000-scale preliminary map of a subset of Lunar Quadrangle 10 ("LQ-10" or the "Marius Quadrangle," see Figures 1 and 2), and discuss the first-order science results. By generating a geologic map of this region, we can constrain the stratigraphic and geologic relationships between features, revealing information about the Moon s chemical and thermal evolution.

The Dynamic Earth.

ERIC Educational Resources Information Center

Siever, Raymond

1983-01-01

Discusses how the earth is a dynamic system that maintains itself in a steady state. Areas considered include large/small-scale earth motions, geologic time, rock and hydrologic cycles, and other aspects dealing with the changing face of the earth. (JN)

Potassium-argon (argon-argon), structural fabrics

USGS Publications Warehouse

Cosca, Michael A.; Rink, W. Jack; Thompson, Jereon

2014-01-01

Definition: 40Ar/39Ar geochronology of structural fabrics: The application of 40Ar/39Ar methods to date development of structural fabrics in geologic samples. Introduction: Structural fabrics develop during rock deformation at variable pressures (P), temperatures (T), fluid compositions (X), and time (t). Structural fabrics are represented in rocks by features such as foliations and shear zones developed at the mm to km scale. In ideal cases, the P-T-X history of a given structural fabric can be constrained using stable isotope, cation exchange, and/or mineral equilibria thermobarometry (Essene 1989). The timing of structural fabric development can be assessed qualitatively using geologic field observations or quantitatively using isotope-based geochronology. High-precision geochronology of the thermal and fluid flow histories associated with structural fabric development can answer fundamental geologic questions including (1) when hydrothermal fluids transported and deposited ore minerals, ...

Geologic utility of small-scale airphotos

NASA Technical Reports Server (NTRS)

Clark, M. M.

1969-01-01

The geologic value of small scale airphotos is emphasized by describing the application of high altitude oblique and 1:120,000 to 1:145,000 scale vertical airphotos to several geologic problems in California. These examples show that small-scale airphotos can be of use to geologists in the following ways: (1) high altitude, high oblique airphotos show vast areas in one view; and (2) vertical airphotos offer the most efficient method of discovering the major topographic features and structural and lithologic characteristics of terrain.

Geologic map of the Willow Creek Reservoir SE Quadrangle, Elko, Eureka, and Lander Counties, Nevada

USGS Publications Warehouse

Wallace, Alan R.

2003-01-01

Map Scale: 1:24,000 Map Type: colored geologic map A 1:24,000-scale, full-color geologic map of the Willow CreekReservoir 7.5-minute SE Quadrangle in Elko, Eureka, and LanderCounties, Nevada, with two cross sections and descriptions of 24 rock units. Accompanying text discusses the geology, paleogeography, and formation of the Ivanhoe Hg-Au district.

Introduction to the special issue on “Understanding and predicting change in the coastal ecosystems of the northern Gulf of Mexico”

USGS Publications Warehouse

Brock, John C.; Barras, John A.; Williams, S. Jeffress

2013-01-01

The coastal region of the northern Gulf of Mexico owes its current landscape structure to an array of tectonic, erosional and depositional, climatic, geochemical, hydrological, ecological, and human processes that have resulted in some of the world's most complex, dynamic, productive, and threatened ecosystems. Catastrophic hurricane landfalls, ongoing subsidence and erosion exacerbated by sea-level rise, disintegration of barrier island chains, and high rates of wetland loss have called attention to the vulnerability of northern Gulf coast ecosystems, habitats, built infrastructure, and economy to natural and anthropogenic threats. The devastating hurricanes of 2005 (Katrina and Rita) motivated the U.S. Geological Survey Coastal and Marine Geology Program and partnering researchers to pursue studies aimed at understanding and predicting landscape change and the associated storm hazard vulnerability of northern Gulf coast region ecosystems and human communities. Attaining this science goal requires increased knowledge of landscape evolution on geologic, historical, and human time scales, and analysis of the implications of such changes in the natural and built components of the landscape for hurricane impact susceptibility. This Special Issue of the Journal of Coastal Research communicates northern Gulf of Mexico research results that (1) improve knowledge of prior climates and depositional environments, (2) assess broad regional ecosystem structure and change over Holocene to human time scales, (3) undertake process studies and change analyses of dynamic landscape components, and (4) integrate framework, climate, variable time and spatial scale mapping, monitoring, and discipline-specific process investigations within interdisciplinary studies.

Facilitating the exploitation of ERTS imagery using snow enhancement techniques

NASA Technical Reports Server (NTRS)

Wobber, F. J. (Principal Investigator); Martin, K. R.; Sheffield, C.; Russell, O.; Amato, R. V.

1973-01-01

The author has identified the following significant results. EarthSat has established an effective mail-based method for obtaining timely ground truth (snow depth) information over an extensive area. The method is both efficient and inexpensive compared with the cost of a similarly scaled direct field checking effort. Additional geological information has been acquired which is not shown in geological maps in the area. Excellent quality snow-free ERTS-1 transparencies of the test areas have been received and are being analyzed.

Tectonic and climatic considerations for deep geological disposal of radioactive waste: A UK perspective.

PubMed

McEvoy, F M; Schofield, D I; Shaw, R P; Norris, S

2016-11-15

Identifying and evaluating the factors that might impact on the long-term integrity of a deep Geological Disposal Facility (GDF) and its surrounding geological and surface environment is central to developing a safety case for underground disposal of radioactive waste. The geological environment should be relatively stable and its behaviour adequately predictable so that scientifically sound evaluations of the long-term radiological safety of a GDF can be made. In considering this, it is necessary to take into account natural processes that could affect a GDF or modify its geological environment up to 1millionyears into the future. Key processes considered in this paper include those which result from plate tectonics, such as seismicity and volcanism, as well as climate-related processes, such as erosion, uplift and the effects of glaciation. Understanding the inherent variability of process rates, critical thresholds and likely potential influence of unpredictable perturbations represent significant challenges to predicting the natural environment. From a plate-tectonic perspective, a one million year time frame represents a very short segment of geological time and is largely below the current resolution of observation of past processes. Similarly, predicting climate system evolution on such time-scales, particularly beyond 200ka AP is highly uncertain, relying on estimating the extremes within which climate and related processes may vary with reasonable confidence. The paper highlights some of the challenges facing a deep geological disposal program in the UK to review understanding of the natural changes that may affect siting and design of a GDF. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Exploring the "what if?" in geology through a RESTful open-source framework for cloud-based simulation and analysis

NASA Astrophysics Data System (ADS)

Klump, Jens; Robertson, Jess

2016-04-01

The spatial and temporal extent of geological phenomena makes experiments in geology difficult to conduct, if not entirely impossible and collection of data is laborious and expensive - so expensive that most of the time we cannot test a hypothesis. The aim, in many cases, is to gather enough data to build a predictive geological model. Even in a mine, where data are abundant, a model remains incomplete because the information at the level of a blasting block is two orders of magnitude larger than the sample from a drill core, and we have to take measurement errors into account. So, what confidence can we have in a model based on sparse data, uncertainties and measurement error? Our framework consist of two layers: (a) a ground-truth layer that contains geological models, which can be statistically based on historical operations data, and (b) a network of RESTful synthetic sensor microservices which can query the ground-truth for underlying properties and produce a simulated measurement to a control layer, which could be a database or LIMS, a machine learner or a companies' existing data infrastructure. Ground truth data are generated by an implicit geological model which serves as a host for nested models of geological processes as smaller scales. Our two layers are implemented using Flask and Gunicorn, which are open source Python web application framework and server, the PyData stack (numpy, scipy etc) and Rabbit MQ (an open-source queuing library). Sensor data is encoded using a JSON-LD version of the SensorML and Observations and Measurements standards. Containerisation of the synthetic sensors using Docker and CoreOS allows rapid and scalable deployment of large numbers of sensors, as well as sensor discovery to form a self-organized dynamic network of sensors. Real-time simulation of data sources can be used to investigate crucial questions such as the potential information gain from future sensing capabilities, or from new sampling strategies, or the combination of both, and it enables us to test many "what if?" questions, both in geology and in data engineering. What would we be able to see if we could obtain data at higher resolution? How would real-time data analysis change sampling strategies? Does our data infrastructure handle many new real-time data streams? What feature engineering can be deducted for machine learning approaches? By providing a 'data sandbox' able to scale to realistic geological scenarios we hope to start answering some of these questions. Faults happen in real world networks. Future work will investigate the effect of failure on dynamic sensor networks and the impact on the predictive capability of machine learning algorithms.

Preliminary Geologic Map of the Buxton 7.5' Quadrangle, Washington County, Oregon

USGS Publications Warehouse

Dinterman, Philip A.; Duvall, Alison R.

2009-01-01

This map, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits of the Buxton 7.5-minute quadrangle. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:24,000 or smaller. This plot file and accompanying database depict the distribution of geologic materials and structures at a regional (1:24,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains new information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Unification of small and large time scales for biological evolution: deviations from power law.

PubMed

Chowdhury, Debashish; Stauffer, Dietrich; Kunwar, Ambarish

2003-02-14

We develop a unified model that describes both "micro" and "macro" evolutions within a single theoretical framework. The ecosystem is described as a dynamic network; the population dynamics at each node of this network describes the "microevolution" over ecological time scales (i.e., birth, ageing, and natural death of individual organisms), while the appearance of new nodes, the slow changes of the links, and the disappearance of existing nodes accounts for the "macroevolution" over geological time scales (i.e., the origination, evolution, and extinction of species). In contrast to several earlier claims in the literature, we observe strong deviations from power law in the regime of long lifetimes.

Geologic history of central Chryse Planitia and the Viking 1 landing site, Mars

NASA Technical Reports Server (NTRS)

Craddock, Robert A.; Crumpler, L. S.; Aubele, Jayne C.

1993-01-01

A 1:500,000 scale geologic mapping was undertaken to synthesize the broad-scale geology of Chryse Planitia with the local geology of the Viking 1 landing site. The geology of Mars Transverse Mercators (MTM's) 20047 and 25047 has been presented previously. As part of the goals for the Mars Geologic Mapping program, the rational and scientific objectives for a return mission to Chryse Planitia and the Viking 1 Lander have also been presented. However, in mapping central Chryse Planitia our principle objective was to determine the depositional and erosional history of the Chryse Planitia basin. These results are presented.

The STRATAFORM Project: U.S. Geological Survey geotechnical studies

USGS Publications Warehouse

Minasian, Diane L.; Lee, Homa J.; Locat, Jaques; Orzech, Kevin M.; Martz, Gregory R.; Israel, Kenneth

2001-01-01

This report presents physical property logs of core samples from an offshore area near Eureka, CA. The cores were obtained as part of the STRATAFORM Program (Nittrouer and Kravitz, 1995, 1996), a study investigating how present sedimentation and sediment transport processes influence long-term stratigraphic sequences preserved in the geologic record. The core samples were collected during four separate research cruises to the northern California study area, and data shown in the logs of the cores were collected using a multi-sensor whole core logger. The physical properties collected are useful in identifying stratigraphic units, ground-truthing acoustic imagery and sub-bottom profiles, and in understanding mass movement processes. STRATA FORmation on Margins was initiated in 1994 by the Office of Naval Research, Marine Geology and Geophysics Department as a coordinated multi-investigator study of continental-margin sediment transport processes and stratigraphy (Nittrouer and Kravitz, 1996). The program is investigating the stratigraphic signature of the shelf and slope parts of the continental margins, and is designed to provide a better understanding of the sedimentary record and a better prediction of strata. Specifically, the goals of the STRATAFORM Program are to (Nittrouer and Kravitz, 1995): - determine the geological relevance of short-term physical processes that erode, transport, and deposit particles and those processes that subsequently rework the seabed over time scales - improve capabilities for identifying the processes that form the strata observed within the upper ~100 m of the seabed commonly representing 104-106 years of sedimentation. - synthesize this knowledge and bridge the gap between time scales of sedimentary processes and those of sequence stratigraphy. The STRATAFORM Program is divided into studies of the continental shelf and the continental slope; the geotechnical group within the U.S. Geological Survey provides support to both parts of the project.

Before you make the data interoperable you have to make the people interoperable

NASA Astrophysics Data System (ADS)

Jackson, I.

2008-12-01

In February 2006 a deceptively simple concept was put forward. Could we use the International Year of Planet Earth 2008 as a stimulus to begin the creation of a digital geological map of the planet at a target scale of 1:1 million? Could we design and initiate a project that uniquely mobilises geological surveys around the world to act as the drivers and sustainable data providers of this global dataset? Further, could we synergistically use this geoscientist-friendly vehicle of creating a tangible geological map to accelerate progress of an emerging global geoscience data model and interchange standard? Finally, could we use the project to transfer know-how to developing countries and reduce the length and expense of their learning curve, while at the same time producing geoscience maps and data that could attract interest and investment? These aspirations, plus the chance to generate a global digital geological dataset to assist in the understanding of global environmental problems and the opportunity to raise the profile of geoscience as part of IYPE seemed more than enough reasons to take the proposal to the next stage. In March 2007, in Brighton, UK, 81 delegates from 43 countries gathered together to consider the creation of this global interoperable geological map dataset. The participants unanimously agreed the Brighton "Accord" and kicked off "OneGeology", an initiative that now has the support of more than 85 nations. Brighton was never designed to be a scientific or technical meeting: it was overtly about people and their interaction - would these delegates, with their diverse cultural and technical backgrounds, be prepared to work together to achieve something which, while technically challenging, was not complex in the context of leading edge geoscience informatics. Could we scale up what is a simple informatics model at national level, to deliver global coverage and access? The major challenges for OneGeology (and the deployment of interoperability) are rarely scientific or technical; they were and are the significantly more difficult logistical and "geopolitical - cultural" issues. OneGeology has grown and progressed rapidly to be an international project. It has not only achieved its first phase scientific and technical goals in launching its web map portal with map data from 30 nations at the International Geological Congress in August 2008, but has also attracted substantial scientific, public and media interest around the world. OneGeology is, in every sense, a child of its time - an agile Internet paradigm - a project whose informatics interoperability goals are in reality the total project ethos. The project has been allowed to grow and extend just as fast and as wide as its actors agree to take it, for the most part free from the territoriality and bureaucracy that all too often inhibit such initiatives. It is beyond doubt that a conventionally run (and thus constrained) OneGeology would not have achieved its goals. The OneGeology team has taken enormous strides in a very short space of time and the achievements are considerable. But some new challenges now arise. How will we sustain the project? Where do we take it next? Can OneGeology continue its "liberal" modus operandi? How should we fund and provide continuity for a growing and thus more demanding infrastructure and user base. Should we expand the portal to include map data from academia, commerce and the public (and how to maintain authentication if one does that?) How fast do we increase the sophistication of the informatics and the resolution and diversity of the data? The presentation will describe OneGeology, its current status and the technical and cultural issues involved in trying to move forward interoperability on a global scale.

Tracing Biosignature Preservation of Geothermally Silicified Microbial Textures into the Geological Record.

PubMed

Campbell, Kathleen A; Lynne, Bridget Y; Handley, Kim M; Jordan, Sacha; Farmer, Jack D; Guido, Diego M; Foucher, Frédéric; Turner, Susan; Perry, Randall S

2015-10-01

New Zealand and Argentine (Late Jurassic-Recent) siliceous hot-spring deposits (sinter) reveal preservation pathways of environmentally controlled, microbe-dominated sedimentary facies over geological time scales. Texturally distinctive, laminated to thinly layered, dense and vertically oriented, microtubular "palisade" fabric is common in low-temperature (<40°C) sinter-apron terraces. In modern hot springs, the dark green to brown, sheathed, photosynthetic cyanobacterium Calothrix spp. (family Rivulariaceae) constructs felted palisade mats in shallow terrace(tte) pools actively accreting opaline silica. The resulting stacked layers of silicified coarse filaments-a stromatolite-are highly porous and readily modified by postdepositional environmental perturbations, secondary silica infill, and diagenetic silica phase mineral transformations (opal-A to quartz). Fossil preservation quality is affected by relative timing of silicification, and later environmental and geological events. A systematic approach was used to characterize palisade fabric in sinters of different ages to refine tools for recognizing biosignatures in extreme environments and to track their long-term preservation pathways into the geological record. Molecular techniques, scanning electron microscopy, Raman spectrometry, X-ray powder diffraction, petrography, and lipid biomarker analyses were applied. Results indicate that microbial communities vary at the micron scale and that early and rapid silicification is paramount to long-term preservation, especially where minimal postdepositional disturbance follows fossilization. Overall, it appears that the most robust biomarkers of fossil microbial activity in hot-spring deposits are their characteristic macro- and microtextures and laser micro-Raman identified carbon. Studies of Phanerozoic geothermal deposits with mineralized microbial components are relevant analogs for Precambrian geobiology because early life is commonly preserved as microbial microfossils and biofilms in silica, some of it hydrothermal in origin. Yet the diagenetic "movie" has already been run. Hence, studying younger sinters of a range of ages provides an opportunity to "play it again" and follow the varied influences on biosignatures into the deep-time geological record.

A new reference frame for astronomically-tuned Plio-Pleistocene climate variability derived from a benthic oxygen isotope splice of the Mediterranean

NASA Astrophysics Data System (ADS)

Lourens, L. J.; Ziegler, M.; Konijnendijk, T. Y. M.; Hilgen, F. J.; Bos, R.; Beekvelt, B.; van Loevezijn, A.; Collin, S.

2017-12-01

The astronomical theory of climate has revolutionized our understanding of past climate change and the development of highly accurate geologic time scales for the entire Cenozoic. Most of this understanding has come from the construction of astronomically tuned global ocean benthic foraminiferal oxygen isotope (δ18O) stacked record, derived by the international drilling operations of DSDP, ODP and IODP. The tuning includes fixed phase relationships between the obliquity and precession cycles and the inferred high-latitude climate, i.e. glacial-interglacial, response, which hark back to SPECMAP, using simple ice sheet models and a limited number of radiometric dates. This approach was largely implemented in the widely applied LR04 stack, though LR04 assumed shorter response times for the smaller ice caps during the Pliocene. In the past decades, an astronomically calibrated time scale for the Pliocene and Pleistocene of the Mediterranean has been developed, which has become the reference for the standard Geologic Time Scale. Typical of the Mediterranean marine sediments are the cyclic lithological alternations, reflecting the interference between obliquity and precession-paced low latitude climate variability, such as the African monsoon. Here we present the first benthic foraminiferal based oxygen isotope record of the Mediterranean reference scale, which strikingly mirrors the LR04. We will use this record to discuss the assumed open ocean glacial-interglacial related phase relations over the past 5.3 million years.

Presentation of a High Resolution Time Lapse 3D Groundwater Model of Metsähovi for Calculating the Gravity Effect of Groundwater in Local Scale

NASA Astrophysics Data System (ADS)

Hokkanen, T. M.; Hartikainen, A.; Raja-Halli, A.; Virtanen, H.; Makinen, J.

2015-12-01

INTRODUCTION The aim of this study is to construct a fine resolution time lapse groundwater (GW) model of Metsähovi (MH). GW, geological, and soil moisture (SM) data were collected for several years to achieve the goal. The knowledge of the behavior of the GW at local scale is essential for superconductive gravimeter (SG) investigations performing in MH. DESCRIPTION OF THE DATA Almost 50 sensors have been recorded SM data some 6 years with 1 to 5 minutes sampling frequency. The GW table has been monitored, both in bedrock and in soil, in many stages with all together 15 piezometers. Two geological sampling campaigns were conducted to get the knowledge of hydrological properties of soil in the study area of 200×200 m2 around SG station in MH. PRINCIPLE OF TIME LAPSE 3D HYDROGEOLOGICAL MODEL The model of study site consists of the surfaces of ground and bedrock gridded with 2×2 m2 resolution. The height of GW table was interpolated to 2×2×0.1 m3 grid between GW and SM monitoring points. Close to the outline of the study site and areas lacking of sensors GW table was defined by extrapolation and considering the geological information of the area. The bedrock porosity is 2% and soil porosity determined by geological information and SM recordings is from 5 to 35%. Only fully saturated media is considered in the time lapse model excluding unsaturated one. BENEFICIERS With a new model the fluctuation of GW table can be followed with ranging time lapses from 1 minute to 1 month. The gravity effect caused by the variation of GW table can be calculated more accurate than before in MH. Moreover, the new model can be validated and refined by measured gravity, i.e. hydrological model can be improved by SG recordings (Figure 1).

Geologic mapping of Argyre Planitia

NASA Technical Reports Server (NTRS)

Gorsline, Donn S.; Parker, Timothy J.

1995-01-01

This report describes the results from the geologic mapping of the central and southern Argyre basin of Mars. At the Mars Geologic Mapper's Meeting in Flagstaff during July, 1993, Dave Scott (United States Geological Survey, Mars Geologic Mapping Steering Committee Chair) recommended that all four quadrangles be combined into a single 1:1,000,000 scale map for publication. It was agreed that this would be cost-effective and that the decrease in scale would not compromise the original science goals of the mapping. Tim Parker completed mapping on the 1:500,000 scale base maps, for which all the necessary materials had already been produced, and included the work as a chapter in his dissertation, which was completed in the fall of 1994. Geologic mapping of the two southernmost quadrangles (MTM -55036 and MTM -55043; MTM=Mars Transverse Mercator) was completed as planned during the first year of work. These maps and a detailed draft of the map text were given a preliminary review by Dave Scott during summer, 1993. Geologic mapping of the remaining two quadrangles (MTM -50036 and MTM -50043) was completed by summer, 1994. Results were described at the Mars Geologic Mappers Meeting, held in Pocatello, Idaho, during July, 1994. Funds for the third and final year of the project have been transferred to the Jet Propulsion Laboratory, where Tim Parker will revise and finalize all maps and map text for publication by the United States Geological Survey at the 1:1,000,000 map scale.

Reconstructing relative genome size of vascular plants through geological time.

PubMed

Lomax, Barry H; Hilton, Jason; Bateman, Richard M; Upchurch, Garland R; Lake, Janice A; Leitch, Ilia J; Cromwell, Avery; Knight, Charles A

2014-01-01

The strong positive relationship evident between cell and genome size in both animals and plants forms the basis of using the size of stomatal guard cells as a proxy to track changes in plant genome size through geological time. We report for the first time a taxonomic fine-scale investigation into changes in stomatal guard-cell length and use these data to infer changes in genome size through the evolutionary history of land plants. Our data suggest that many of the earliest land plants had exceptionally large genome sizes and that a predicted overall trend of increasing genome size within individual lineages through geological time is not supported. However, maximum genome size steadily increases from the Mississippian (c. 360 million yr ago (Ma)) to the present. We hypothesise that the functional relationship between stomatal size, genome size and atmospheric CO2 may contribute to the dichotomy reported between preferential extinction of neopolyploids and the prevalence of palaeopolyploidy observed in DNA sequence data of extant vascular plants. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Publications - PDF 99-24A | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Alaska, scale 1:63,360 (6.9 M) Keywords Ar-Ar; Bedrock; Bedrock Geology; Generalized; Geologic; Geologic Map; Geology; Gold; Lode; Non-Metals; Paleontology; Plutonic; Plutonic Hosted; STATEMAP Project

Evaluating Experience-Based Geologic Field Instruction: Lessons Learned from A Large-Scale Eye-Tracking Experiment

NASA Astrophysics Data System (ADS)

Tarduno, J. A.; Walders, K.; Bono, R. K.; Pelz, J.; Jacobs, R.

2015-12-01

A course centered on experience-based learning in field geology has been offered ten times at the University of Rochester. The centerpiece of the course is a 10-day field excursion to California featuring a broad cross-section of the geology of the state, from the San Andreas Fault to Death Valley. Here we describe results from a large-scale eye-tracking experiment aimed at understanding how experts and novices acquire visual geologic information. One ultimate goal of the project is to determine whether expert gaze patterns can be quantified to improve the instruction of beginning geology students. Another goal is to determine if aspects of the field experience can be transferred to the classroom/laboratory. Accordingly, ultra-high resolution segmented panoramic images have been collected at key sites visited during the field excursion. We have found that strict controls are needed in the field to obtain meaningful data; this often involves behavior atypical of geologists (e.g. limiting the field of view prior to data collection and placing time limits on scene viewing). Nevertheless some general conclusions can be made from a select data set. After an initial quick search, experts tend to exhibit scanning behavior that appears to support hypothesis testing. Novice fixations appear to define a scattered search pattern and/or one distracted by geologic noise in a scene. Noise sources include modern erosion features and vegetation. One way to quantify noise is through the use of saliency maps. With the caveat that our expert data set is small, our preliminary analysis suggests that experts tend to exhibit top-down behavior (indicating hypothesis driven responses) whereas novices show bottom-up gaze patterns, influenced by more salient features in a scene. We will present examples and discuss how these observations might be used to improve instruction.

Field reconnaissance geologic mapping of the Columbia Hills, Mars, based on Mars Exploration Rover Spirit and MRO HiRISE observations

USGS Publications Warehouse

Crumpler, L.S.; Arvidson, R. E.; Squyres, S. W.; McCoy, T.; Yingst, A.; Ruff, S.; Farrand, W.; McSween, Y.; Powell, M.; Ming, D. W.; Morris, R.V.; Bell, J.F.; Grant, J.; Greeley, R.; DesMarais, D.; Schmidt, M.; Cabrol, N.A.; Haldemann, A.; Lewis, K.W.; Wang, A.E.; Schroder, C.; Blaney, D.; Cohen, B.; Yen, A.; Farmer, J.; Gellert, Ralf; Guinness, E.A.; Herkenhoff, K. E.; Johnson, J. R.; Klingelhfer, G.; McEwen, A.; Rice, J.W.; Rice, M.; deSouza, P.; Hurowitz, J.

2011-01-01

Chemical, mineralogic, and lithologic ground truth was acquired for the first time on Mars in terrain units mapped using orbital Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (MRO HiRISE) image data. Examination of several dozen outcrops shows that Mars is geologically complex at meter length scales, the record of its geologic history is well exposed, stratigraphic units may be identified and correlated across significant areas on the ground, and outcrops and geologic relationships between materials may be analyzed with techniques commonly employed in terrestrial field geology. Despite their burial during the course of Martian geologic time by widespread epiclastic materials, mobile fines, and fall deposits, the selective exhumation of deep and well-preserved geologic units has exposed undisturbed outcrops, stratigraphic sections, and structural information much as they are preserved and exposed on Earth. A rich geologic record awaits skilled future field investigators on Mars. The correlation of ground observations and orbital images enables construction of a corresponding geologic reconnaissance map. Most of the outcrops visited are interpreted to be pyroclastic, impactite, and epiclastic deposits overlying an unexposed substrate, probably related to a modified Gusev crater central peak. Fluids have altered chemistry and mineralogy of these protoliths in degrees that vary substantially within the same map unit. Examination of the rocks exposed above and below the major unconformity between the plains lavas and the Columbia Hills directly confirms the general conclusion from remote sensing in previous studies over past years that the early history of Mars was a time of more intense deposition and modification of the surface. Although the availability of fluids and the chemical and mineral activity declined from this early period, significant later volcanism and fluid convection enabled additional, if localized, chemical activity. Copyright ?? 2011 by the American Geophysical Union.

Radio-astrochronology of the Agrio Formation (Neuquén Basin, Argentina) to reduce the uncertainties of the geological time scale in Early Cretaceous times

NASA Astrophysics Data System (ADS)

Martinez, Mathieu; Beatriz, Aguirre-Urreta; Marina, Lescano; Julieta, Omarini; Maisa, Tunik; Thomas, Frederichs; Anna-Leah, Nickl; Heiko, Pälike

2017-04-01

Important discrepancies between the numerical ages stated by the Geological Time Scale 2016 and radio-astrochronological works have been reported in the last years (Aguirre-Urreta et al., 2015; Martinez et al., 2015; Ogg et al., 2016). Large uncertainties notably exist for the Valanginian-Hauterivian stages for which the recently provided timescales are still debated. Here, we present an astronomical calibration for the Agrio Formation (Neuquén Basin, Argentina) to better constraint the durations of the Valanginian and the Hauterivian stages. The formation is divided into a lower and an upper member (called Pilmatué and Agua de la Mula members, respectively) composed of marl-limestone alternations deposited in a semi-pelagic to outer ramp environment and related to an orbital forcing (Sagasti, 2005). A rapidly (<0.5 myr) deposited member of continental sandstone, separates these two members. A total of 2130 bulk-rock samples have been collected each 25 cm and their mass-corrected magnetic susceptibility has been measured to detect lithological cycles. Spectral analyses were performed using the multi-taper method and the time-frequency weighted fast Fourier transform. In the lower part of the Pilmatué Member (Lower Agrio), the record of the 405-kyr eccentricity cycle is obvious but its amplitude promptly decreases at younger intervals. However, the orbital cycles of precession, obliquity and 100-kyr eccentricity are recorded, allowing the duration of the Pilmatué Member to be assessed at 4.70 myr. Anchoring this duration to the CA-ID-TIMS age of 130.39 ± 0.16 Ma provided in the Pilmatué Member, the age of this member ranges from 133.76 to 129.07 ± 0.16 Ma. The age of the top of the Lower Agrio slightly overlaps the age of the base of the Upper Agrio (129.09 ± 0.16 Ma). Such an overlap falls in the range of the uncertainties in the CA-ID-TIMS ages. First correlations to the Tethyan area suggest that the early Hauterivian has a duration of 2.1 myr, falling in the range of uncertainty mentioned by Martinez et al. (2015) (2.5 ± 0.4 myr), but being much longer than the duration of 1.21 myr proposed in the geological time scale 2016 (Ogg et al., 2016), suggesting the duration of the Hauterivian stage has to be increased by, at least, 0.9 myr for the next compilation. References: Aguirre-Urreta, B., et al., 2015. Filling the gap: new precise Early Cretaceous radioisotopic ages from the Andes. Geological Magazine 152, 557-564. Martinez, M., et al., 2015. Astrochronology of the Valanginian-Hauterivian stages (Early Cretaceous): chronological relationships between the Paraná-Etendeka large igneous province, the Weissert and the Faraoni events. Global and Planetary Change 131, 158-173. Ogg, J.G., et al., 2016. A Concise Geological Time Scale 2016. Elsevier B.V., 243 pp. Sagasti, G., 2005. Hemipelagic record of orbitally-induced dilution cycles in Lower Cretaceous sediments of the Neuquén Basin, in Veiga, G.D., Spaletti, L.A., Howell, J.A. and Schwarz E. (Eds.). The Neuquén Basin, Argentina: A Case Study in Sequence Stratigraphy and Basin Dynamics. Geological Society, London, Special Publications 252, 231-250.

Methane on the Move: natural greenhouse gas emissions over geological time

NASA Astrophysics Data System (ADS)

Horsfield, B.; di Primio, R.; Kroeger, K. F.; Schicks, J. M.

2008-12-01

The mass of organic carbon in sedimentary basins amounts to a staggering 1016 tons, dwarfing the mass contained in coal, oil, gas and all living systems by ten thousand-fold. The changing fate of this giant mass during subsidence and uplift, via chemical, physical and biological processes, is known to ultimately control fossil energy resource occurrence worldwide. But what has been overlooked and/or ignored until now is its enormous capacity for driving global climate: only a tiny degree of leakage, particularly when focussed through the clathrate cycle, can result in high greenhouse gas emissions. Understanding the workings of sedimentary basins in time and space is fundamental to gaining insights into Earth's climate. Here we shall present an integrated framework based on petroleum system modelling that will ultimately quantify methane migration and emission from one hundred of the world's most prolific petroliferous sedimentary basins. Timing of hydrocarbon generation from globally occurring prolific Jurassic and Cretaceous source rocks is regarded to be the key factor in quantifying gas release. Combined thermogenic and biogenic methane fluxes are the base for prediction of gas hydrate formation through time and space, by application of kinetics developed in the laboratory to geological scenarios. Results are calibrated in basin scale by emission structure evaluation (mud volcanoes, carbonate mounds, pockmarks) and on a global scale by proxy data from sedimentary archives and local atmospheric data. Identifying potential climate feedback processes over a geological time line that spans the Cenozoic requires a comprehensive understanding of source-sink relationships by coupling these feedstock fluxes with gas hydrate stability considerations, deep biosphere activity, ocean and atmosphere modelling

Digital geologic map and GIS database of Venezuela

USGS Publications Warehouse

Garrity, Christopher P.; Hackley, Paul C.; Urbani, Franco

2006-01-01

The digital geologic map and GIS database of Venezuela captures GIS compatible geologic and hydrologic data from the 'Geologic Shaded Relief Map of Venezuela,' which was released online as U.S. Geological Survey Open-File Report 2005-1038. Digital datasets and corresponding metadata files are stored in ESRI geodatabase format; accessible via ArcGIS 9.X. Feature classes in the geodatabase include geologic unit polygons, open water polygons, coincident geologic unit linework (contacts, faults, etc.) and non-coincident geologic unit linework (folds, drainage networks, etc.). Geologic unit polygon data were attributed for age, name, and lithologic type following the Lexico Estratigrafico de Venezuela. All digital datasets were captured from source data at 1:750,000. Although users may view and analyze data at varying scales, the authors make no guarantee as to the accuracy of the data at scales larger than 1:750,000.

MyDTW - Dynamic Time Warping program for stratigraphical time series

NASA Astrophysics Data System (ADS)

Kotov, Sergey; Paelike, Heiko

2017-04-01

One of the general tasks in many geological disciplines is matching of one time or space signal to another. It can be classical correlation between two cores or cross-sections in sedimentology or marine geology. For example, tuning a paleoclimatic signal to a target curve, driven by variations in the astronomical parameters, is a powerful technique to construct accurate time scales. However, these methods can be rather time-consuming and can take ours of routine work even with the help of special semi-automatic software. Therefore, different approaches to automate the processes have been developed during last decades. Some of them are based on classical statistical cross-correlations such as the 'Correlator' after Olea [1]. Another ones use modern ideas of dynamic programming. A good example is as an algorithm developed by Lisiecki and Lisiecki [2] or dynamic time warping based algorithm after Pälike [3]. We introduce here an algorithm and computer program, which are also stemmed from the Dynamic Time Warping algorithm class. Unlike the algorithm of Lisiecki and Lisiecki, MyDTW does not lean on a set of penalties to follow geological logics, but on a special internal structure and specific constrains. It differs also from [3] in basic ideas of implementation and constrains design. The algorithm is implemented as a computer program with a graphical user interface using Free Pascal and Lazarus IDE and available for Windows, Mac OS, and Linux. Examples with synthetic and real data are demonstrated. Program is available for free download at http://www.marum.de/Sergey_Kotov.html . References: 1. Olea, R.A. Expert systems for automated correlation and interpretation of wireline logs // Math Geol (1994) 26: 879. doi:10.1007/BF02083420 2. Lisiecki L. and Lisiecki P. Application of dynamic programming to the correlation of paleoclimate records // Paleoceanography (2002), Volume 17, Issue 4, pp. 1-1, CiteID 1049, doi: 10.1029/2001PA000733 3. Pälike, H. Extending the astronomical calibration of the Geological Time Scale PhD thesis, University of Cambridge, (2002)

'Cape capture': Geologic data and modeling results suggest the holocene loss of a Carolina Cape

USGS Publications Warehouse

Thieler, E.R.; Ashton, A.D.

2011-01-01

For more than a century, the origin and evolution of the set of cuspate forelands known as the Carolina Capes-Hatteras, Lookout, Fear, and Romain-off the eastern coast of the United States have been discussed and debated. The consensus conceptual model is not only that these capes existed through much or all of the Holocene transgression, but also that their number has not changed. Here we describe bathymetric, lithologic, seismic, and chronologic data that suggest another cape may have existed between Capes Hatteras and Lookout during the early to middle Holocene. This cape likely formed at the distal end of the Neuse-Tar-Pamlico fiuvial system during the early Holocene transgression, when this portion of the shelf was fiooded ca. 9 cal (calibrated) kyr B.P., and was probably abandoned by ca. 4 cal kyr B.P., when the shoreline attained its present general configuration. Previously proposed mechanisms for cape formation suggest that the large-scale, rhythmic pattern of the Carolina Capes arose from a hydrodynamic template or the preexisting geologic framework. Numerical modeling, however, suggests that the number and spacing of capes can be dynamic, and that a coast can self-organize in response to a high-angle-wave instability in shoreline shape. In shoreline evolution model simulations, smaller cuspate forelands are subsumed by larger neighbors over millennial time scales through a process of 'cape capture.' The suggested former cape in Raleigh Bay represents the first interpreted geological evidence of dynamic abandonment suggested by the self-organization hypothesis. Cape capture may be a widespread process in coastal environments with large-scale rhythmic shoreline features; its preservation in the sedimentary record will vary according to geologic setting, physical processes, and sea-level history. ?? 2011 Geological Society of America.

Evidence for Enhanced Matrix Diffusion in Geological Environment

NASA Astrophysics Data System (ADS)

Sato, Kiminori; Fujimoto, Koichiro; Nakata, Masataka; Shikazono, Naotatsu

2013-01-01

Molecular diffusion in rock matrix, called as matrix diffusion, has been appreciated as a static process for elemental migration in geological environment that has been acknowledged in the context of geological disposal of radioactive waste. However, incomprehensible enhancement of matrix diffusion has been reported at a number of field test sites. Here, the matrix diffusion of saline water at Horonobe, Hokkaido, Japan is highlighted directly probing angstrom-scale pores on a field scale up to 1 km by positron--positronium annihilation spectroscopy. The first application of positron--positronium annihilation spectroscopy to field-scale geophysical research reveals the slight variation of angstrom-scale pores influenced by saline water diffusion with complete accuracy. We found widely interconnected 3 Å pores, which offer the pathway of saline water diffusion with the highly enhanced effective matrix diffusion coefficient of 4× 10-6 cm2 s-1. The present findings provide unambiguous evidence that the angstrom-scale pores enhance effective matrix diffusion on a field scale in geological environment.

Geologic Mapping of the Lunar South Pole Quadrangle (LQ-30)

NASA Technical Reports Server (NTRS)

Mest, S. C.; Berman, D. C.; Petro, N. E.

2010-01-01

In this study we use recent image, spectral and topographic data to map the geology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-7]. The overall objective of this research is to constrain the geologic evolution of LQ-30 (60 -90 S, 0 - 180 ) with specific emphasis on evaluation of a) the regional effects of impact basin formation, and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Determining the geologic history of LQ-30 and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of potential resources (e.g., H, Fe, Th) and their relationships with surface materials.

Geological Interpretation of PSInSAR Data at Regional Scale

PubMed Central

Meisina, Claudia; Zucca, Francesco; Notti, Davide; Colombo, Alessio; Cucchi, Anselmo; Savio, Giuliano; Giannico, Chiara; Bianchi, Marco

2008-01-01

Results of a PSInSAR™ project carried out by the Regional Agency for Environmental Protection (ARPA) in Piemonte Region (Northern Italy) are presented and discussed. A methodology is proposed for the interpretation of the PSInSAR™ data at the regional scale, easy to use by the public administrations and by civil protection authorities. Potential and limitations of the PSInSAR™ technique for ground movement detection on a regional scale and monitoring are then estimated in relationship with different geological processes and various geological environments. PMID:27873940

Negative Emissions Technology

NASA Astrophysics Data System (ADS)

Day, Danny

2006-04-01

Although `negative emissions' of carbon dioxide need not, in principle, involve use of biological processes to draw carbon out of the atmosphere, such `agricultural' sequestration' is the only known way to remove carbon from the atmosphere on time scales comparable to the time scale for anthropogenic increases in carbon emissions. In order to maintain the `negative emissions' the biomass must be used in such a way that the resulting carbon dioxide is separated and permanently sequestered. Two options for sequestration are in the topsoil and via geologic carbon sequestration. The former has multiple benefits, but the latter also is needed. Thus, although geologic carbon sequestration is viewed skeptically by some environmentalists as simply a way to keep using fossil fuels---it may be a key part of reversing accelerating climate forcing if rapid climate change is beginning to occur. I will first review the general approach of agricultural sequestration combined with use of resulting biofuels in a way that permits carbon separation and then geologic sequestration as a negative emissions technology. Then I discuss the process that is the focus of my company---the EPRIDA cycle. If deployed at a sufficiently large scale, it could reverse the increase in CO2 concentrations. I also estimate of benefits --carbon and other---of large scale deployment of negative emissions technologies. For example, using the EPRIDA cycle by planting and soil sequestering carbon in an area abut In 3X the size of Texas would remove the amount of carbon that is being accumulated worldwide each year. In addition to the atmospheric carbon removal, the EPRIDA approach also counters the depletion of carbon in the soil---increasing topsoil and its fertility; reduces the excess nitrogen in the water by eliminating the need for ammonium nitrate fertilizer and reduces fossil fuel reliance by providing biofuel and avoiding natural gas based fertilizer production.

An Integrated Geologic Framework for EarthScope's USArray

NASA Astrophysics Data System (ADS)

Tikoff, Basil; van der Pluijm, Ben; Hibbard, Jim; Keller, George Randy; Mogk, David; Selverstone, Jane; Walker, Doug

2006-06-01

The GeoFrame initiative is a new geologic venture that focuses on the construction, stabilization, and modification of the North American continent through time. The initiative's goals can be achieved through systematic integration of geologic knowledge-and particularly geologic time-with the unprecedented Earth imaging to be collected under the USArray program of EarthScope (http://www.earthscope.org/usarray). The GeoFrame initiative encourages a cooperative community approach to collecting and sharing data and will take a coast-to-coast perspective of the continent, focusing not only on the major geologic provinces, but also on the boundaries between these provinces. GeoFrame also offers a tangible, `you can see it and touch it' basis for a national approach to education and outreach in the Earth sciences. The EarthScope project is a massive undertaking to investigate the structure and evolution of the North American continent. Sponsored by the U.S. National Science Foundation (NSF), EarthScope uses modern observational, analytical, and telecommunications technologies to establish fundamental and applied research in the Earth's dynamics, contributing to natural resource exploration and development, the mitigation of geologic hazards and risk, and a greater public understanding of solid Earth systems. One part of this project is USArray, a moving, continent-scale network of seismic stations designed to provide a foundation for the study of the lithosphere and deep Earth.

Inner shelf morphologic controls on the dynamics of the beach and bar system, Fire Island, New York

USGS Publications Warehouse

Hapke, Cheryl J.; Schwab, William C.; Gayes, Paul T.; McCoy, Clay; Viso, Richard; Lentz, Erika E.; Rosati, Julie D.; Wang, Ping; Roberts, Tiffany M.

2011-01-01

The mechanism of sediment exchange between offshore sand ridges and the beach at Fire Island, New York is largely unknown. However, recent evidence from repeat nearshore bathymetry surveys, coupled with the complex but consistent bar morphology and patterns of shoreline change demonstrate that there is a feedback occurring between the regional geologic framework and modern processes. Analysis of bathymetric survey data provides direct confirmation that the offshore ridges are connected to the shoreface and are spatially persistent. The fixed nature of the nearshore morphology is further supported by time series camera data that indicate persistent bars with breaks that re-form in the same locations. A long-term time series of shoreline change shows distinct zones of erosion and accretion that are pervasive over time scales greater than a half-century, and their length-scales are similar to the spacing of the offshore ridge-trough system. The first-order geologic framework is responsible for the existence and locations of the ridges and troughs, which then influence the morphodynamics of the beach and bar system.

Mass Extinctions and Biosphere-Geosphere Stability

NASA Astrophysics Data System (ADS)

Rothman, Daniel; Bowring, Samuel

2015-04-01

Five times in the past 500 million years, mass extinctions have resulted in the loss of greater than three-fourths of living species. Each of these events is associated with significant environmental change recorded in the carbon-isotopic composition of sedimentary rocks. There are also many such environmental events in the geologic record that are not associated with mass extinctions. What makes them different? Two factors appear important: the size of the environmental perturbation, and the time scale over which it occurs. We show that the natural perturbations of Earth's carbon cycle during the past 500 million years exhibit a characteristic rate of change over two orders of magnitude in time scale. This characteristic rate is consistent with the maximum rate that limits quasistatic (i.e., near steady-state) evolution of the carbon cycle. We identify this rate with marginal stability, and show that mass extinctions occur on the fast, unstable side of the stability boundary. These results suggest that the great extinction events of the geologic past, and potentially a "sixth extinction" associated with modern environmental change, are characterized by common mechanisms of instability.

Global Change and the Earth System

NASA Astrophysics Data System (ADS)

Pollack, Henry N.

2004-08-01

The Earth system in recent years has come to mean the complex interactions of the atmosphere, biosphere, lithosphere and hydrosphere, through an intricate network of feedback loops. This system has operated over geologic time, driven principally by processes with long time scales. Over the lifetime of the solar system, the Sun has slowly become more radiant, and the geography of continents and oceans basins has evolved via plate tectonics. This geography has placed a first-order constraint on the circulation of ocean waters, and thus has strongly influenced regional and global climate. At shorter time scales, the Earth system has been influenced by Milankovitch orbital factors and occasional exogenous events such as bolide impacts. Under these influences the system chugged along for eons, until some few hundred thousand years ago, when one remarkable species evolved: Homo sapiens. As individuals, humans are of course insignificant in shaping the Earth system, but collectively the six billion human occupants of the planet now rival ``natural'' processes in modifying the Earth system. This profound human influence underlies the dubbing of the present epoch of geologic history as the ``Anthropocene.''

Global Warming in Geologic Time

ScienceCinema

Archer, David

2018-01-01

The notion is pervasive in the climate science community and in the public at large that the climate impacts of fossil fuel CO2 release will only persist for a few centuries. This conclusion has no basis in theory or models of the atmosphere / ocean carbon cycle, which we review here. The largest fraction of the CO2 recovery will take place on time scales of centuries, as CO2 invades the ocean, but a significant fraction of the fossil fuel CO2, ranging in published models in the literature from 20-60%, remains airborne for a thousand years or longer. Ultimate recovery takes place on time scales of hundreds of thousands of years, a geologic longevity typically associated in public perceptions with nuclear waste. The glacial / interglacial climate cycles demonstrate that ice sheets and sea level respond dramatically to millennial-timescale changes in climate forcing. There are also potential positive feedbacks in the carbon cycle, including methane hydrates in the ocean, and peat frozen in permafrost, that are most sensitive to the long tail of the fossil fuel CO2 in the atmosphere.

The application of geography markup language (GML) to the geological sciences

NASA Astrophysics Data System (ADS)

Lake, Ron

2005-11-01

GML 3.0 became an adopted specification of the Open Geospatial Consortium (OGC) in January 2003, and is rapidly emerging as the world standard for the encoding, transport and storage of all forms of geographic information. This paper looks at the application of GML to one of the more challenging areas of automated geography, namely the geological sciences. Specific features of GML of interest to geologists are discussed and then illustrated through a series of geological case studies. We conclude the paper with a discussion of anticipated geological web services that GML will enable. GML is written in XML and makes use of XML Schema for extensibility. It can be used both to represent or model geographic objects and to transport them across the Internet. In this way it serves as the foundation for all manner of geographic web services. Unlike vertical application grammars such as LandXML, GML was intended to define geographic application languages, and hence is applicable to any geographic domain including forestry, environmental sciences, geology and oceanography. This paper provides a review of the basic features of GML that are fundamental to the geological sciences including geometry, coverages, observations, reference systems and temporality. These constructs are then employed in a series of simple geological case studies including structural geological description, surficial geology, representation of geological time scales, mineral occurrences, geohazards and geochemical reconnaissance.

Geomorphic effectiveness of a long profile shape and the role of inherent geological controls in the Himalayan hinterland area of the Ganga River basin, India

NASA Astrophysics Data System (ADS)

Sonam; Jain, Vikrant

2018-03-01

Long profiles of rivers provide a platform to analyse interaction between geological and geomorphic processes operating at different time scales. Identification of an appropriate model for river long profile becomes important in order to establish a quantitative relationship between the profile shape, its geomorphic effectiveness, and inherent geological characteristics. This work highlights the variability in the long profile shape of the Ganga River and its major tributaries, its impact on stream power distribution pattern, and role of the geological controls on it. Long profile shapes are represented by the sum of two exponential functions through the curve fitting method. We have shown that coefficients of river long profile equations are governed by the geological characteristics of subbasins. These equations further define the spatial distribution pattern of stream power and help to understand stream power variability in different geological terrains. Spatial distribution of stream power in different geological terrains successfully explains spatial variability in geomorphic processes within the Himalayan hinterland area. In general, the stream power peaks of larger rivers lie in the Higher Himalaya, and rivers in the eastern hinterland area are characterised by the highest magnitude of stream power.

Scale Determinants of Fiscal Investment in Geological Exploration: Evidence from China

PubMed Central

Lu, Linna; Lei, Yalin

2013-01-01

With the continued growth in demand for mineral resources and China's efforts in increasing investment in geological prospecting, fiscal investment in geological exploration becomes a research hotspot. This paper examines the yearly relationship among fiscal investment in geological exploration of the current term, that of the last term and prices of mining rights over the period 1999–2009. Hines and Catephores' investment acceleration model is applied to describe the scale determinants of fiscal investment in geological exploration which are value-added of mining rights, value of mining rights and fiscal investment in the last term. The results indicate that when value-added of mining rights, value of mining rights or fiscal investment in the last term moves at 1 unit, fiscal investment in the current term will move 0.381, 1.094 or 0.907 units respectively. In order to determine the scale of fiscal investment in geological exploration for the current year, the Chinese government should take fiscal investment in geological exploration for the last year and the capital stock of the previous investments into account. In practice, combination of government fiscal investment in geological exploration with its performance evaluation can create a virtuous circle of capital management mechanism. PMID:24204652

Scale determinants of fiscal investment in geological exploration: evidence from China.

PubMed

Lu, Linna; Lei, Yalin

2013-01-01

With the continued growth in demand for mineral resources and China's efforts in increasing investment in geological prospecting, fiscal investment in geological exploration becomes a research hotspot. This paper examines the yearly relationship among fiscal investment in geological exploration of the current term, that of the last term and prices of mining rights over the period 1999-2009. Hines and Catephores' investment acceleration model is applied to describe the scale determinants of fiscal investment in geological exploration which are value-added of mining rights, value of mining rights and fiscal investment in the last term. The results indicate that when value-added of mining rights, value of mining rights or fiscal investment in the last term moves at 1 unit, fiscal investment in the current term will move 0.381, 1.094 or 0.907 units respectively. In order to determine the scale of fiscal investment in geological exploration for the current year, the Chinese government should take fiscal investment in geological exploration for the last year and the capital stock of the previous investments into account. In practice, combination of government fiscal investment in geological exploration with its performance evaluation can create a virtuous circle of capital management mechanism.

A Hydrostratigraphic System for Modeling Groundwater Flow and Radionuclide Migration at the Corrective Action Unit Scale, Nevada Test Site and Surrounding Areas, Clark, Lincoln, and Nye Counties, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prothro, Lance; Drellack Jr., Sigmund; Mercadante, Jennifer

2009-01-31

Underground Test Area (UGTA) corrective action unit (CAU) groundwater flow and contaminant transport models of the Nevada Test Site (NTS) and vicinity are built upon hydrostratigraphic framework models (HFMs) that utilize the hydrostratigraphic unit (HSU) as the fundamental modeling component. The delineation and three-dimensional (3-D) modeling of HSUs within the highly complex geologic terrain that is the NTS requires a hydrostratigraphic system that is internally consistent, yet flexible enough to account for overlapping model areas, varied geologic terrain, and the development of multiple alternative HFMs. The UGTA CAU-scale hydrostratigraphic system builds on more than 50 years of geologic and hydrologicmore » work in the NTS region. It includes 76 HSUs developed from nearly 300 stratigraphic units that span more than 570 million years of geologic time, and includes rock units as diverse as marine carbonate and siliciclastic rocks, granitic intrusives, rhyolitic lavas and ash-flow tuffs, and alluvial valley-fill deposits. The UGTA CAU-scale hydrostratigraphic system uses a geology-based approach and two-level classification scheme. The first, or lowest, level of the hydrostratigraphic system is the hydrogeologic unit (HGU). Rocks in a model area are first classified as one of ten HGUs based on the rock’s ability to transmit groundwater (i.e., nature of their porosity and permeability), which at the NTS is mainly a function of the rock’s primary lithology, type and degree of postdepositional alteration, and propensity to fracture. The second, or highest, level within the UGTA CAU-scale hydrostratigraphic system is the HSU, which is the fundamental mapping/modeling unit within UGTA CAU-scale HFMs. HSUs are 3-D bodies that are represented in the finite element mesh for the UGTA groundwater modeling process. HSUs are defined systematically by stratigraphically organizing HGUs of similar character into larger HSUs designations. The careful integration of stratigraphic information in the development of HSUs is important to assure individual HSUs are internally consistent, correlatable, and mappable throughout all the model areas.« less

Digital geologic map and Landsat image map of parts of Loralai, Sibi, Quetta, and Khuzar Divisions, Balochistan Province, west-central Pakistan

USGS Publications Warehouse

Maldonado, Florian; Menga, Jan Mohammad; Khan, Shabid Hasan; Thomas, Jean-Claude

2011-01-01

This generalized digital geologic map of west-central Pakistan is a product of the Balochistan Coal-Basin Synthesis Study, which was part of a cooperative program of the Geological Survey of Pakistan and the United States Geological Survey. The original nondigital map was published by Maldonado and others (1998). Funding was provided by the Government of Pakistan and the United States Agency for International Development. The sources of geologic map data are primarily 1:253,440-scale geologic maps obtained from Hunting Survey Corporation (1961) and the geologic map of the Muslim Bagh Ophiolite Complex and Bagh Complex area. The geology was modified based on reconnaissance field work and photo interpretation of 1:250,000-scale Landsat Thematic Mapper photo image. The descriptions and thicknesses of map units were based on published and unpublished reports and converted to U.S. Geological Survey format. In the nomenclature of the Geological Survey of Pakistan, there is both an Urak Group and an Urak Formation.

Geologic maps of the eastern Alaska Range, Alaska (1:63,360 scale)

USGS Publications Warehouse

Nokleberg, Warren J.; Aleinikoff, John N.; Bond, Gerard C.; Ferrians, Oscar J.; Herzon, Paige L.; Lange, Ian M.; Miyaoka, Ronny T.; Richter, Donald H.; Schwab, Carl E.; Silva, Steven R.; Smith, Thomas E.; Zehner, Richard E.

2015-01-01

This report provides a description of map units for a suite of 44 inch-to-mile (1:63,360-scale) geologic quadrangle maps of the eastern Alaska Range. This report also contains a geologic and tectonic summary and a comprehensive list of references pertaining to geologic mapping and specialized studies of the region. In addition to the geologic maps of the eastern Alaska Range, this package includes a list of map units and an explanation of map symbols and abbreviations. The geologic maps display detailed surficial and bedrock geology, structural and stratigraphic data, portrayal of the active Denali fault that bisects the core of the east–west-trending range, and portrayal of other young faults along the north and south flanks of the range.

Large earthquake rates from geologic, geodetic, and seismological perspectives

NASA Astrophysics Data System (ADS)

Jackson, D. D.

2017-12-01

Earthquake rate and recurrence information comes primarily from geology, geodesy, and seismology. Geology gives the longest temporal perspective, but it reveals only surface deformation, relatable to earthquakes only with many assumptions. Geodesy is also limited to surface observations, but it detects evidence of the processes leading to earthquakes, again subject to important assumptions. Seismology reveals actual earthquakes, but its history is too short to capture important properties of very large ones. Unfortunately, the ranges of these observation types barely overlap, so that integrating them into a consistent picture adequate to infer future prospects requires a great deal of trust. Perhaps the most important boundary is the temporal one at the beginning of the instrumental seismic era, about a century ago. We have virtually no seismological or geodetic information on large earthquakes before then, and little geological information after. Virtually all-modern forecasts of large earthquakes assume some form of equivalence between tectonic- and seismic moment rates as functions of location, time, and magnitude threshold. That assumption links geology, geodesy, and seismology, but it invokes a host of other assumptions and incurs very significant uncertainties. Questions include temporal behavior of seismic and tectonic moment rates; shape of the earthquake magnitude distribution; upper magnitude limit; scaling between rupture length, width, and displacement; depth dependence of stress coupling; value of crustal rigidity; and relation between faults at depth and their surface fault traces, to name just a few. In this report I'll estimate the quantitative implications for estimating large earthquake rate. Global studies like the GEAR1 project suggest that surface deformation from geology and geodesy best show the geography of very large, rare earthquakes in the long term, while seismological observations of small earthquakes best forecasts moderate earthquakes up to about magnitude 7. Regional forecasts for a few decades, like those in UCERF3, could be improved by calibrating tectonic moment rate to past seismicity rates. Century-long forecasts must be speculative. Estimates of maximum magnitude and rate of giant earthquakes over geologic time scales require more than science.

Digital geologic map data for the Ozark National Scenic Riverways and adjacent areas along the Current River and Jacks Fork, Missouri

USGS Publications Warehouse

Weary, David J.; Orndorff, Randall C.; Harrison, Richard W.; Weems, Robert E.

2016-09-23

The geology of the Ozark National Scenic Riverways (ONSR) in southern Missouri has been mapped at 1:24,000 scale. This endeavor was achieved through the combined efforts of U.S. Geological Survey and Missouri Geological Survey individual quadrangle mapping and additional fieldwork by the authors of this report. Geologic data covering the area of the ONSR and a 1-mile (1.6-kilometer) buffer zone surrounding the park, as well as geologic data from a few key adjoining areas, have been compiled into a single, seamless geographic information system database. The intent is to provide base geologic information for natural science research and land management in the park and surrounding areas. The data are served online at ScienceBase (https://www.sciencebase.gov/catalog/), where they are provided in Environmental Systems Research Institute (ESRI) file geodatabase format, and are accompanied by metadata files. These data can be accessed at: http://dx.doi.org/10.5066/F7CJ8BKB. Additional detailed geologic information about the ONSR and surrounding areas is available in the separate 1:24,000-scale quadrangle maps and in a 1:100,000-scale map and report on the regional geology.

Geologic map of the Reyes Peak quadrangle, Ventura County, California

USGS Publications Warehouse

Minor, Scott A.

2004-01-01

New 1:24,000-scale geologic mapping in the Cuyama 30' x 60' quadrangle, in support of the USGS Southern California Areal Mapping Project (SCAMP), is contributing to a more complete understanding of the stratigraphy, structure, and tectonic evolution of the complex junction area between the NW-trending Coast Ranges and EW-trending western Transverse Ranges. The 1:24,000-scale geologic map of the Reyes Peak quadrangle, located in the eastern part of the Cuyama map area, is the final of six contiguous 7 ?' quadrangle geologic maps compiled for a more detailed portrayal and reevaluation of geologic structures and rock units shown on previous maps of the region (Carman, 1964; Dibblee, 1972; Vedder and others, 1973). SCAMP digital geologic maps of the five other contiguous quadrangles have recently been published (Minor, 1999; Kellogg, 1999, 2003; Stone and Cossette, 2000; Kellogg and Miggins, 2002). This digital compilation presents a new geologic map database for the Reyes Peak 7?' quadrangle, which is located in southern California about 75 km northwest of Los Angeles. The map database is at 1:24,000-scale resolution.

A study of the usefulness of Skylab EREP data for earth resources studies in Australia

NASA Technical Reports Server (NTRS)

Lambert, B. P.; Benson, M. L.; Borough, C. J.; Myers, B. J.; Maffi, C. E.; Simpson, C. J.; Perry, W. J.; Burns, K. L.; Shepherd, J.; Beattie, R. (Principal Investigator)

1975-01-01

The author has identified the following significant results. In subhumid, vegetated areas, S190B photography: (1) has a potentially operational role in detecting lineaments in 1:100,000 scale geological mapping and in major civil engineering surveys; (2) is of limited value for regional lithological mapping at 1:500,000 scale; and (3) provided much useful synoptic information and some detailed information of direct value to the mapping of nonmineral natural resources such as vegetation, land soil, and water. In arid, well exposed areas, S190B photography could be used: (1) with a limited amount of field traverses, to produce reliable 1:500,000 scale geological maps of sedimentary sequences; (2) to update superficial geology on 1:250,000 scale maps; and (3) together with the necessary field studies, to prepare landform, soil, and vegetation maps at 1:1,000,000 scale. Skylab photography was found to be more useful than LANDSAT images for small scale mapping of geology and land types, and for the revision of topographic maps at 1:100,000 scale, because of superior spatial resolution and stereoscopic coverage.

Fractals in geology and geophysics

NASA Technical Reports Server (NTRS)

Turcotte, Donald L.

1989-01-01

The definition of a fractal distribution is that the number of objects N with a characteristic size greater than r scales with the relation N of about r exp -D. The frequency-size distributions for islands, earthquakes, fragments, ore deposits, and oil fields often satisfy this relation. This application illustrates a fundamental aspect of fractal distributions, scale invariance. The requirement of an object to define a scale in photograhs of many geological features is one indication of the wide applicability of scale invariance to geological problems; scale invariance can lead to fractal clustering. Geophysical spectra can also be related to fractals; these are self-affine fractals rather than self-similar fractals. Examples include the earth's topography and geoid.

An Exercise on Magnetic-Anomaly Profiles and the Geomagnetic Polar-Reversal Time Scale.

ERIC Educational Resources Information Center

Shea, James Herbert

1988-01-01

Develops an exercise in which students use magnetic-profile data gathered in the South Pacific to test the Vine-Matthews-Morley hypothesis. Uses the Eltanin 19N and 20N profiles. Relates the exercise to 20 current geology texts. (MVL)

Simulation of geothermal water extraction in heterogeneous reservoirs using dynamic unstructured mesh optimisation

NASA Astrophysics Data System (ADS)

Salinas, P.; Pavlidis, D.; Jacquemyn, C.; Lei, Q.; Xie, Z.; Pain, C.; Jackson, M.

2017-12-01

It is well known that the pressure gradient into a production well increases with decreasing distance to the well. To properly capture the local pressure drawdown into the well a high grid or mesh resolution is required; moreover, the location of the well must be captured accurately. In conventional simulation models, the user must interact with the model to modify grid resolution around wells of interest, and the well location is approximated on a grid defined early in the modelling process.We report a new approach for improved simulation of near wellbore flow in reservoir scale models through the use of dynamic mesh optimisation and the recently presented double control volume finite element method. Time is discretized using an adaptive, implicit approach. Heterogeneous geologic features are represented as volumes bounded by surfaces. Within these volumes, termed geologic domains, the material properties are constant. Up-, cross- or down-scaling of material properties during dynamic mesh optimization is not required, as the properties are uniform within each geologic domain. A given model typically contains numerous such geologic domains. Wells are implicitly coupled with the domain, and the fluid flows is modelled inside the wells. The method is novel for two reasons. First, a fully unstructured tetrahedral mesh is used to discretize space, and the spatial location of the well is specified via a line vector, ensuring its location even if the mesh is modified during the simulation. The well location is therefore accurately captured, the approach allows complex well trajectories and wells with many laterals to be modelled. Second, computational efficiency is increased by use of dynamic mesh optimization, in which an unstructured mesh adapts in space and time to key solution fields (preserving the geometry of the geologic domains), such as pressure, velocity or temperature, this also increases the quality of the solutions by placing higher resolution where required to reduce an error metric based on the Hessian of the field. This allows the local pressure drawdown to be captured without user¬ driven modification of the mesh. We demonstrate that the method has wide application in reservoir ¬scale models of geothermal fields, and regional models of groundwater resources.

The “Anthropocene” epoch: Scientific decision or political statement?

USGS Publications Warehouse

Finney, Stanley C.; Edwards, Lucy E.

2016-01-01

The proposal for the “Anthropocene” epoch as a formal unit of the geologic time scale has received extensive attention in scientific and public media. However, most articles on the Anthropocene misrepresent the nature of the units of the International Chronostratigraphic Chart, which is produced by the International Commission on Stratigraphy (ICS) and serves as the basis for the geologic time scale. The stratigraphic record of the Anthropocene is minimal, especially with its recently proposed beginning in 1945; it is that of a human lifespan, and that definition relegates considerable anthropogenic change to a “pre-Anthropocene.” The utility of the Anthropocene requires careful consideration by its various potential users. Its concept is fundamentally different from the chronostratigraphic units that are established by ICS in that the documentation and study of the human impact on the Earth system are based more on direct human observation than on a stratigraphic record. The drive to officially recognize the Anthropocene may, in fact, be political rather than scientific.

Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

DOE PAGES

Mirus, Benjamin B.; Halford, Keith J.; Sweetkind, Donald; ...

2016-02-18

The suitability of geologic frameworks for extrapolating hydraulic conductivity (K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks providemore » the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. As a result, testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.« less

Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

USGS Publications Warehouse

Mirus, Benjamin B.; Halford, Keith J.; Sweetkind, Donald; Fenelon, Joseph M.

2016-01-01

The suitability of geologic frameworks for extrapolating hydraulic conductivity (K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks provide the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. Testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.

Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mirus, Benjamin B.; Halford, Keith J.; Sweetkind, Donald

The suitability of geologic frameworks for extrapolating hydraulic conductivity (K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks providemore » the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. As a result, testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.« less

Geological heritage under strong urbanization pressure: El-Mokattam and Abu Roash as examples from Cairo, Egypt

NASA Astrophysics Data System (ADS)

AbdelMaksoud, Kholoud M.; Al-Metwaly, Wael M.; Ruban, Dmitry A.; Yashalova, Natalia N.

2018-05-01

Urban geological heritage is prone to anthropogenic pressure linked to urbanization. In order to understand the necessity of conservation of such a heritage located in two areas of Cairo (Egypt), namely El-Mokattam and Abu Roash, their assessment is undertaken. It is established that the both areas possess geological heritage. As much as five types of the latter are represented in each of them. The most important in El-Mokattam is geomorphological type (the Mokattam Mountain itself), and the most important in Abu Roash are palaeogeographical (facies and palaeoecosystems) and structural (outcrop-scale fold and faults) types. In the both areas, the geological heritage is destroyed because of rapid and often uncontrolled (even illegal) urbanization. According to the results of the satellite images interpretation, the urban area has grown by 1.4 times in El-Mokattam and 3.4 times in Abu Roash during the period of 2000-2017 when many unique objects were damaged and destroyed. Some aesthetic properties have been also lost, which has decreased the important of these objects to tourists, as well as many students and researchers. Assigning official protected status and possible geopark creation can facilitate efficient conservation of the urban geological heritage of Cairo.

Adaptive dynamics on an environmental gradient that changes over a geological time-scale.

PubMed

Fortelius, Mikael; Geritz, Stefan; Gyllenberg, Mats; Toivonen, Jaakko

2015-07-07

The standard adaptive dynamics framework assumes two timescales, i.e. fast population dynamics and slow evolutionary dynamics. We further assume a third timescale, which is even slower than the evolutionary timescale. We call this the geological timescale and we assume that slow climatic change occurs within this timescale. We study the evolution of our model population over this very slow geological timescale with bifurcation plots of the standard adaptive dynamics framework. The bifurcation parameter being varied describes the abiotic environment that changes over the geological timescale. We construct evolutionary trees over the geological timescale and observe both gradual phenotypic evolution and punctuated branching events. We concur with the established notion that branching of a monomorphic population on an environmental gradient only happens when the gradient is not too shallow and not too steep. However, we show that evolution within the habitat can produce polymorphic populations that inhabit steep gradients. What is necessary is that the environmental gradient at some point in time is such that the initial branching of the monomorphic population can occur. We also find that phenotypes adapted to environments in the middle of the existing environmental range are more likely to branch than phenotypes adapted to extreme environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

An evaluation of the carbon sequestration potential of the Cambro-Ordovician Strata of the Illinois and Michigan basins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leetaru, Hannes

2014-12-01

The studies summarized herein were conducted during 2009–2014 to investigate the utility of the Knox Group and St. Peter Sandstone deeply buried geologic strata for underground storage of carbon dioxide (CO 2), a practice called CO 2 sequestration (CCS). In the subsurface of the midwestern United States, the Knox and associated strata extend continuously over an area approaching 500,000 sq. km, about three times as large as the State of Illinois. Although parts of this region are underlain by the deeper Mt. Simon Sandstone, which has been proven by other Department of Energy-funded research as a resource for CCS, themore » Knox strata may be an additional CCS resource for some parts of the Midwest and may be the sole geologic storage (GS) resource for other parts. One group of studies assembles, analyzes, and presents regional-scale and point-scale geologic information that bears on the suitability of the geologic formations of the Knox for a CCS project. New geologic and geo-engineering information was developed through a small-scale test of CO 2 injection into a part of the Knox, conducted in western Kentucky. These studies and tests establish the expectation that, at least in some locations, geologic formations within the Knox will (a) accept a commercial-scale flow rate of CO 2 injected through a drilled well; (b) hold a commercial-scale mass of CO 2 (at least 30 million tons) that is injected over decades; and (c) seal the injected CO 2 within the injection formations for hundreds to thousands of years. In CCS literature, these three key CCS-related attributes are called injectivity, capacity, and containment. The regional-scale studies show that reservoir and seal properties adequate for commercial-scale CCS in a Knox reservoir are likely to extend generally throughout the Illinois and Michigan Basins. Information distinguishing less prospective subregions from more prospective fairways is included in this report. Another group of studies report the results of reservoir flow simulations that estimate the progress and outcomes of hypothetical CCS projects carried out within the Knox (particularly within the Potosi Dolomite subunit, which, in places, is highly permeable) and within the overlying St. Peter Sandstone. In these studies, the regional-scale information and a limited amount of detailed data from specific boreholes is used as the basis for modeling the CO 2 injection process (dynamic modeling). The simulation studies were conducted progressively, with each successive study designed to refine the conclusions of the preceding one or to answer additional questions. The simulation studies conclude that at Decatur, Illinois or a geologically similar site, the Potosi Dolomite reservoir may provide adequate injectivity and capacity for commercial-scale injection through a single injection well. This conclusion depends on inferences from seismic-data attributes that certain highly permeable horizons observed in the wells represent laterally persistent, porous vuggy zones that are vertically more common than initially evident from wellbore data. Lateral persistence of vuggy zones is supported by isotopic evidence that the conditions that caused vug development (near-surface processes) were of regional rather than local scale. Other studies address aspects of executing and managing a CCS project that targets a Knox reservoir. These studies cover well drilling, public interactions, representation of datasets and conclusions using geographic information system (GIS) platforms, and risk management.« less

Preliminary integrated geologic map databases for the United States: Digital data for the geology of southeast Alaska

USGS Publications Warehouse

Gehrels, George E.; Berg, Henry C.

2006-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set of 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

DIGITAL GEOLOGIC MAP OF SHERMAN QUADRANGLE, NORTH CENTRAL TEXAS (CD-ROM)

EPA Science Inventory

This compact disc contains digital data sets of the surficial geology and geologic faults for the 1:250,000-scale Sherman quadrangle, North Central Texas, and can be used to make geologic maps, and determine approximate areas and locations of various geologic units. The source d...

Finite-difference time-domain modelling of through-the-Earth radio signal propagation

NASA Astrophysics Data System (ADS)

Ralchenko, M.; Svilans, M.; Samson, C.; Roper, M.

2015-12-01

This research seeks to extend the knowledge of how a very low frequency (VLF) through-the-Earth (TTE) radio signal behaves as it propagates underground, by calculating and visualizing the strength of the electric and magnetic fields for an arbitrary geology through numeric modelling. To achieve this objective, a new software tool has been developed using the finite-difference time-domain method. This technique is particularly well suited to visualizing the distribution of electromagnetic fields in an arbitrary geology. The frequency range of TTE radio (400-9000 Hz) and geometrical scales involved (1 m resolution for domains a few hundred metres in size) involves processing a grid composed of millions of cells for thousands of time steps, which is computationally expensive. Graphics processing unit acceleration was used to reduce execution time from days and weeks, to minutes and hours. Results from the new modelling tool were compared to three cases for which an analytic solution is known. Two more case studies were done featuring complex geologic environments relevant to TTE communications that cannot be solved analytically. There was good agreement between numeric and analytic results. Deviations were likely caused by numeric artifacts from the model boundaries; however, in a TTE application in field conditions, the uncertainty in the conductivity of the various geologic formations will greatly outweigh these small numeric errors.

Evaluation of Lithofacies Up-Scaling Methods for Probabilistic Prediction of Carbon Dioxide Behavior

NASA Astrophysics Data System (ADS)

Park, J. Y.; Lee, S.; Lee, Y. I.; Kihm, J. H.; Kim, J. M.

2017-12-01

Behavior of carbon dioxide injected into target reservoir (storage) formations is highly dependent on heterogeneities of geologic lithofacies and properties. These heterogeneous lithofacies and properties basically have probabilistic characteristics. Thus, their probabilistic evaluation has to be implemented properly into predicting behavior of injected carbon dioxide in heterogeneous storage formations. In this study, a series of three-dimensional geologic modeling is performed first using SKUA-GOCAD (ASGA and Paradigm) to establish lithofacies models of the Janggi Conglomerate in the Janggi Basin, Korea within a modeling domain. The Janggi Conglomerate is composed of mudstone, sandstone, and conglomerate, and it has been identified as a potential reservoir rock (clastic saline formation) for geologic carbon dioxide storage. Its lithofacies information are obtained from four boreholes and used in lithofacies modeling. Three different up-scaling methods (i.e., nearest to cell center, largest proportion, and random) are applied, and lithofacies modeling is performed 100 times for each up-scaling method. The lithofacies models are then compared and analyzed with the borehole data to evaluate the relative suitability of the three up-scaling methods. Finally, the lithofacies models are converted into coarser lithofacies models within the same modeling domain with larger grid blocks using the three up-scaling methods, and a series of multiphase thermo-hydrological numerical simulation is performed using TOUGH2-MP (Zhang et al., 2008) to predict probabilistically behavior of injected carbon dioxide. The coarser lithofacies models are also compared and analyzed with the borehole data and finer lithofacies models to evaluate the relative suitability of the three up-scaling methods. Three-dimensional geologic modeling, up-scaling, and multiphase thermo-hydrological numerical simulation as linked methodologies presented in this study can be utilized as a practical probabilistic evaluation tool to predict behavior of injected carbon dioxide and even to analyze its leakage risk. This work was supported by the Korea CCS 2020 Project of the Korea Carbon Capture and Sequestration R&D Center (KCRC) funded by the National Research Foundation (NRF), Ministry of Science and ICT (MSIT), Korea.

A sensitivity analysis on seismic tomography data with respect to CO2 saturation of a CO2 geological sequestration field

NASA Astrophysics Data System (ADS)

Park, Chanho; Nguyen, Phung K. T.; Nam, Myung Jin; Kim, Jongwook

2013-04-01

Monitoring CO2 migration and storage in geological formations is important not only for the stability of geological sequestration of CO2 but also for efficient management of CO2 injection. Especially, geophysical methods can make in situ observation of CO2 to assess the potential leakage of CO2 and to improve reservoir description as well to monitor development of geologic discontinuity (i.e., fault, crack, joint, etc.). Geophysical monitoring can be based on wireline logging or surface surveys for well-scale monitoring (high resolution and nallow area of investigation) or basin-scale monitoring (low resolution and wide area of investigation). In the meantime, crosswell tomography can make reservoir-scale monitoring to bridge the resolution gap between well logs and surface measurements. This study focuses on reservoir-scale monitoring based on crosswell seismic tomography aiming describe details of reservoir structure and monitoring migration of reservoir fluid (water and CO2). For the monitoring, we first make a sensitivity analysis on crosswell seismic tomography data with respect to CO2 saturation. For the sensitivity analysis, Rock Physics Models (RPMs) are constructed by calculating the values of density and P and S-wave velocities of a virtual CO2 injection reservoir. Since the seismic velocity of the reservoir accordingly changes as CO2 saturation changes when the CO2 saturation is less than about 20%, while when the CO2 saturation is larger than 20%, the seismic velocity is insensitive to the change, sensitivity analysis is mainly made when CO2 saturation is less than 20%. For precise simulation of seismic tomography responses for constructed RPMs, we developed a time-domain 2D elastic modeling based on finite difference method with a staggered grid employing a boundary condition of a convolutional perfectly matched layer. We further make comparison between sensitivities of seismic tomography and surface measurements for RPMs to analysis resolution difference between them. Moreover, assuming a similar reservoir situation to the CO2 storage site in Nagaoka, Japan, we generate time-lapse tomographic data sets for the corresponding CO2 injection process, and make a preliminary interpretation of the data sets.

Issues of scale, location and geologic terrain related to Salt Lake City and Baltimore-Washington metropolitan areas

USGS Publications Warehouse

Cleaves, E.T.; Godfrey, A.E.; ,

2004-01-01

Planning and development of expanding metropolitan regions require consideration of earth science issues related to issues involving scale, space (location), geologic terrain and physiographic units, and information transfer. This paper explores these matters with examples from the Salt Lake City, Utah area and Mid-Atlantic region of Baltimore-Washington that include water supply and natural hazards (earthquakes, landslides, and sinkholes.) Information transfer methods using physiographic units at national, regional, local and site scales serve to communicate relevant geologic constraint and natural resource information.

Towards a High-resolution Time Scale for the Early Devonian

NASA Astrophysics Data System (ADS)

Dekkers, M. J.; da Silva, A. C.

2017-12-01

High-resolution time scales are crucial to understand Earth's history in detail. The construction of a robust geological time scale, however, inevitably becomes increasingly harder further back in time. Uncertainties associated with anchor radiometric ages increase in size, not speaking of the mere presence of suitable datable strata. However, durations of stages can be tightly constrained by making use of cyclic expressions in sediments, an approach that revolutionized the Cenozoic time scale. When precisely determined durations are stitched together, ultimately, a very precise time scale is the result. For the Mesozoic and Paleozoic an astronomical solution as a tuning target is not available but the dominant periods of eccentricity, obliquity and precession are reasonably well constrained for the entire Phanerozoic which enables their detection by means of spectral analysis. Eccentricity is time-invariant and is used as the prime building block. Here we focus on the Early Devonian, on its lowermost three stages: the Lochkovian, Pragian and Emsian. The uncertainties on the Devonian stage boundaries are currently in the order of several millions of years. The preservation of climatic cycles in diagenetically or even anchimetamorphically affected successions, however, is essential. The fit of spectral peak ratios with those calculated for orbital cycles, is classically used as a strong argument for a preserved climatic signal. Here we use primarily the low field magnetic susceptibility (MS) as proxy parameter, supported by gamma-ray spectrometry to test for consistency. Continuous Wavelet Transform, Evolutive Harmonic Analysis, Multitaper Method, and Average Spectral Misfit are used to reach an optimal astronomical interpretation. We report on classic Early Devonian sections from the Czech Republic: the Pozar-CS (Lochkovian and Pragian), Pod Barrandovem (Pragian and Lower Emsian), and Zlichov (Middle-Upper Emsian). Also a Middle-Upper Emsian section from the US (Road 199 section, Kingston, New York) will be targeted. Strata display Milankovitch cycles to a varying visible degree but spectral analysis of MS with supporting magnetic property tests enables to constrain durations up to an order of magnitude more precise than in the current (2012) Geological Time Scale.

Global geological map of Venus

NASA Astrophysics Data System (ADS)

Ivanov, Mikhail A.; Head, James W.

2011-10-01

The surface area of Venus (∼460×106 km2) is ∼90% of that of the Earth. Using Magellan radar image and altimetry data, supplemented by Venera-15/16 radar images, we compiled a global geologic map of Venus at a scale of 1:10 M. We outline the history of geological mapping of the Earth and planets to illustrate the importance of utilizing the dual stratigraphic classification approach to geological mapping. Using this established approach, we identify 13 distinctive units on the surface of Venus and a series of structures and related features. We present the history and evolution of the definition and characterization of these units, explore and assess alternate methods and approaches that have been suggested, and trace the sequence of mapping from small areas to regional and global scales. We outline the specific defining nature and characteristics of these units, map their distribution, and assess their stratigraphic relationships. On the basis of these data, we then compare local and regional stratigraphic columns and compile a global stratigraphic column, defining rock-stratigraphic units, time-stratigraphic units, and geological time units. We use superposed craters, stratigraphic relationships and impact crater parabola degradation to assess the geologic time represented by the global stratigraphic column. Using the characteristics of these units, we interpret the geological processes that were responsible for their formation. On the basis of unit superposition and stratigraphic relationships, we interpret the sequence of events and processes recorded in the global stratigraphic column. The earliest part of the history of Venus (Pre-Fortunian) predates the observed surface geological features and units, although remnants may exist in the form of deformed rocks and minerals. We find that the observable geological history of Venus can be subdivided into three distinctive phases. The earlier phase (Fortunian Period, its lower stratigraphic boundary cannot be determined with the available data sets) involved intense deformation and building of regions of thicker crust (tessera). This was followed by the Guineverian Period. Distributed deformed plains, mountain belts, and regional interconnected groove belts characterize the first part and the vast majority of coronae began to form during this time. The second part of the Guineverian Period involved global emplacement of vast and mildly deformed plains of volcanic origin. A period of global wrinkle ridge formation largely followed the emplacement of these plains. The third phase (Atlian Period) involved the formation of prominent rift zones and fields of lava flows unmodified by wrinkle ridges that are often associated with large shield volcanoes and, in places, with earlier-formed coronae. Atlian volcanism may continue to the present. About 70% of the exposed surface of Venus was resurfaced during the Guineverian Period and only about 16% during the Atlian Period. Estimates of model absolute ages suggest that the Atlian Period was about twice as long as the Guineverian and, thus, characterized by significantly reduced rates of volcanism and tectonism. The three major phases of activity documented in the global stratigraphy and geological map, and their interpreted temporal relations, provide a basis for assessing the geodynamical processes operating earlier in Venus history that led to the preserved record.

Preliminary bedrock geologic map of the Seward Peninsula, Alaska, and accompanying conodont data

USGS Publications Warehouse

Till, Alison B.; Dumoulin, Julie A.; Werdon, Melanie B.; Bleick, Heather A.

2010-01-01

This 1:500,000-scale geologic map depicts the bedrock geology of Seward Peninsula, western Alaska, on the North American side of the Bering Strait. The map encompasses all of the Teller, Nome, Solomon, and Bendeleben 1:250,000-scale quadrangles, and parts of the Shishmaref, Kotzebue, Candle, and Norton Bay 1:250,000-scale quadrangles (sheet 1; sheet 2). The geologic map is presented on Sheet 1. The pamphlet includes an introductory text, unit descriptions, tables of geochronologic data, and an appendix containing conodont (microfossil) data and a text about those data. Sheet 2 shows metamorphic and tectonic units, conodont color alteration indices, key metamorphic minerals, and locations of geochronology samples listed in the pamphlet.

CONSIDERATIONS FOR A REGULATORY FRAMEWORK FOR LARGE-SCALE GEOLOGIC SEQUESTRATION OF CARBON DIOXIDE: A NORTH AMERICAN PERSPECTIVE

EPA Science Inventory

Large scale geologic sequestration (GS) of carbon dioxide poses a novel set of challenges for regulators. This paper focuses on the unique needs of large scale GS projects in light of the existing regulatory regimes in the United States and Canada and identifies several differen...

The Role of Geologic Mapping in NASA PDSI Planning

NASA Astrophysics Data System (ADS)

Williams, D. A.; Skinner, J. A.; Radebaugh, J.

2017-12-01

Geologic mapping is an investigative process designed to derive the geologic history of planetary objects at local, regional, hemispheric or global scales. Geologic maps are critical products that aid future exploration by robotic spacecraft or human missions, support resource exploration, and provide context for and help guide scientific discovery. Creation of these tools, however, can be challenging in that, relative to their terrestrial counterparts, non-terrestrial planetary geologic maps lack expansive field-based observations. They rely, instead, on integrating diverse data types wth a range of spatial scales and areal coverage. These facilitate establishment of geomorphic and geologic context but are generally limited with respect to identifying outcrop-scale textural details and resolving temporal and spatial changes in depositional environments. As a result, planetary maps should be prepared with clearly defined contact and unit descriptions as well as a range of potential interpretations. Today geologic maps can be made from images obtained during the traverses of the Mars rovers, and for every new planetary object visited by NASA orbital or flyby spacecraft (e.g., Vesta, Ceres, Titan, Enceladus, Pluto). As Solar System Exploration develops and as NASA prepares to send astronauts back to the Moon and on to Mars, the importance of geologic mapping will increase. In this presentation, we will discuss the past role of geologic mapping in NASA's planetary science activities and our thoughts on the role geologic mapping will have in exploration in the coming decades. Challenges that planetary mapping must address include, among others: 1) determine the geologic framework of all Solar System bodies through the systematic development of geologic maps at appropriate scales, 2) develop digital Geographic Information Systems (GIS)-based mapping techniques and standards to assist with communicating map information to the scientific community and public, 3) develop public awareness of the role and application of geologic map-information to the resolution of national issues relevant to planetary science and eventual off-planet resource assessments, 4) use topical science to drive mapping in areas likely to be determined vital to the welfare of endeavors related to planetary science and exploration.

Improved Strength and Damage Modeling of Geologic Materials

NASA Astrophysics Data System (ADS)

Stewart, Sarah; Senft, Laurel

2007-06-01

Collisions and impact cratering events are important processes in the evolution of planetary bodies. The time and length scales of planetary collisions, however, are inaccessible in the laboratory and require the use of shock physics codes. We present the results from a new rheological model for geological materials implemented in the CTH code [1]. The `ROCK' model includes pressure, temperature, and damage effects on strength, as well as acoustic fluidization during impact crater collapse. We demonstrate that the model accurately reproduces final crater shapes, tensile cracking, and damaged zones from laboratory to planetary scales. The strength model requires basic material properties; hence, the input parameters may be benchmarked to laboratory results and extended to planetary collision events. We show the effects of varying material strength parameters, which are dependent on both scale and strain rate, and discuss choosing appropriate parameters for laboratory and planetary situations. The results are a significant improvement in models of continuum rock deformation during large scale impact events. [1] Senft, L. E., Stewart, S. T. Modeling Impact Cratering in Layered Surfaces, J. Geophys. Res., submitted.

Geologic map and map database of parts of Marin, San Francisco, Alameda, Contra Costa, and Sonoma counties, California

USGS Publications Warehouse

Blake, M.C.; Jones, D.L.; Graymer, R.W.; digital database by Soule, Adam

2000-01-01

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (mageo.txt, mageo.pdf, or mageo.ps), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:62,500 or smaller general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (mageo.txt, mageo.pdf, or mageo.ps), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:62,500 or smaller.

Resurfacing event observed in Morpheos basin (Eridania Planitia) and the implications to the formation and timing of Waikato and Reull Valles, Mars

NASA Astrophysics Data System (ADS)

Kostama, V.-P.; Kukkonen, S.; Raitala, J.

2017-06-01

The large scale outflow channels of the Hellas impact basin are characteristic to its eastern rim region. Although the majority of the valles are located in the large-scale topographic trough connecting Hesperia Planum and Hellas basin, the most far-reaching of them, Reull Vallis is situated to the south-southeast of this trough cutting through Promethei Terra. Reull Vallis and the general geology of the region has been studied in the past, but new higher resolution image data enables us to look into the details of the features implicating the fluvial history of the region. Photogeological mapping using the available data and extensive crater counting utilizing CTX, HiRISE and HRSC provided new insights to the timing of the regional events and episodes. The study resulted in more detailed age constraints compared to the previous results from Viking images. These calculations and the geological study of the upper WMR system (Waikato Vallis - Morpheos basin - Reull Vallis) region and southern Hesperia Planum enabled us to estimate the time-frame of the (fluid) infilling of this reservoir to a model time period of 3.67-3.52 Ga which is thus also the time of the visible activity of the upper Reull Vallis and Waikato Vallis outflow channels. The results also more explicitly defined the size of previously identified Morpheos basin (confined to the 500-550 m contour lines). We also present a geological analysis of the upper parts of the WMR system, and using the observations and calculations, present an updated view of the evolution of the system and associated region.

Bedrock geologic map of Vermont

USGS Publications Warehouse

Ratcliffe, Nicholas M.; Stanley, Rolfe S.; Gale, Marjorie H.; Thompson, Peter J.; Walsh, Gregory J.; With contributions by Hatch, Norman L.; Rankin, Douglas W.; Doolan, Barry L.; Kim, Jonathan; Mehrtens, Charlotte J.; Aleinikoff, John N.; McHone, J. Gregory; Cartography by Masonic, Linda M.

2011-01-01

The Bedrock Geologic Map of Vermont is the result of a cooperative agreement between the U.S. Geological Survey (USGS) and the State of Vermont. The State's complex geology spans 1.4 billion years of Earth's history. The new map comes 50 years after the most recent map of the State by Charles G. Doll and others in 1961 and a full 150 years since the publication of the first geologic map of Vermont by Edward Hitchcock and others in 1861. At a scale of 1:100,000, the map shows an uncommon level of detail for State geologic maps. Mapped rock units are primarily based on lithology, or rock type, to facilitate derivative studies in multiple disciplines. The 1961 map was compiled from 1:62,500-scale or smaller maps. The current map was created to integrate more detailed (1:12,000- to 1:24,000-scale) modern and older (1:62,500-scale) mapping with the theory of plate tectonics to provide a framework for geologic, tectonic, economic, hydrogeologic, and environmental characterization of the bedrock of Vermont. The printed map consists of three oversize sheets (52 x 76 inches). Sheets 1 and 2 show the southern and northern halves of Vermont, respectively, and can be trimmed and joined so that the entire State can be displayed as a single entity. These sheets also include 10 cross sections and a geologic structure map. Sheet 3 on the front consists of descriptions of 486 map units, a correlation of map units, and references cited. Sheet 3 on the back features a list of the 195 sources of geologic map data keyed to an index map of 7.5-minute quadrangles in Vermont, as well as a table identifying ages of rocks dated by uranium-lead zircon geochronology.

Hydrogeologic controls on streamflow sensitivity to climate variation

Treesearch

Anne Jefferson; Anne Nolin; Sarah Lewis; Christina Tague

2008-01-01

Climate models project warmer temperatures for the north-west USA, which will result in reduced snowpacks and decreased summer streamflow. This paper examines how groundwater, snowmelt, and regional climate patterns control discharge at multiple time scales, using historical records from two watersheds with contrasting geological properties and drainage efficiencies....

Influences of spatial scale and soil permeability on relationships between land cover and baseflow stream nutrient concentrations

EPA Science Inventory

The Little Miami River (LMR) basin, dominated by agriculture, contains two geologically-distinct regions; a glaciated northern till plain with soils three times more permeable than a southern, pre-Wisconsinan drift plain. The influences of two landscape measures, percent row crop...

Updating the planetary time scale: focus on Mars

USGS Publications Warehouse

Tanaka, Kenneth L.; Quantin-Nataf, Cathy

2013-01-01

Formal stratigraphic systems have been developed for the surface materials of the Moon, Mars, Mercury, and the Galilean satellite Ganymede. These systems are based on geologic mapping, which establishes relative ages of surfaces delineated by superposition, morphology, impact crater densities, and other relations and features. Referent units selected from the mapping determine time-stratigraphic bases and/or representative materials characteristic of events and periods for definition of chronologic units. Absolute ages of these units in some cases can be estimated using crater size-frequency data. For the Moon, the chronologic units and cratering record are calibrated by radiometric ages measured from samples collected from the lunar surface. Model ages for other cratered planetary surfaces are constructed primarily by estimating cratering rates relative to that of the Moon. Other cratered bodies with estimated surface ages include Venus and the Galilean satellites of Jupiter. New global geologic mapping and crater dating studies of Mars are resulting in more accurate and detailed reconstructions of its geologic history.

A geologic analysis of the Side-Looking Airborne Radar imagery of southern New England

USGS Publications Warehouse

Banks, Paul T.

1975-01-01

Analysis of the side looking airborn radar imagery of Massachusetts, Connecticut and Rhode Island indicates that radar shows the topography in great detail. Since bedrock geologic features are frequently expressed in the topography the radar lends itself to geologic interpretation. The radar was studied by comparisons with field mapped geologic data first at a scale of approximately 1:125,000 and then at a scale of 1:500,000. The larger scale comparison revealed that faults, minor faults, joint sets, bedding and foliation attitudes, lithology and lithologic contacts all have a topographic expression interpretable on the imagery. Surficial geologic features were far less visible on the imagery over most of the area studied. The smaller scale comparisons revealed a pervasive, near orthogonal fracture set cutting all types and ages of rock and trending roughly N40?E and N30?W. In certain places the strike of bedding and foliation attitudes and some lithologic Contacts were visible in addition to the fractures. Fracturing in southern New England is apparently far more important than has been previously recognized. This new information, together with the visibility of many bedding and foliation attitudes and lithologic contacts, indicates the importance of radar imagery in improving the geologic interpretation of an area.

A comparison of Gemini and ERTS imagery obtained over southern Morocco

NASA Technical Reports Server (NTRS)

Blodget, H. W.; Anderson, A. T.

1973-01-01

A mosaic constructed from three ERTS MSS band 5 images enlarged to 1:500,000 compares favorably with a similar scale geologic map of southern Morocco, and a near-similar scale Gemini 5 photo pair. A comparative plot of lineations and generalized geology on the three formats show that a significantly greater number of probable fractures are visible on the ERTS imagery than on the Gemini photography, and that both orbital formats show several times more lineaments than were previously mapped. A plot of mineral occurrences on the structural overlays indicates that definite structure-mineralization relationships exist; this finding is used to define underdeveloped areas which are prospective for mineralization. More detailed mapping is possible using MSS imagery than on Gemini 5 photographs, and in addition, the ERTS format is not restricted to limited coverage.

Overview of geology and tectonic evolution of the Baikal-Tuva area.

PubMed

Gladkochub, Dmitry; Donskaya, Tatiana

2009-01-01

This chapter provides the results of geological investigations of the main tectonic units of the Baikal-Tuva region (southwestern part of Siberia) during the last decades: the ancient Siberian craton and adjacent areas of the Central Asian Orogenic belt. In the framework of these main units we describe small-scale blocks (terranes) with focus on details of their inner structure and evolution through time. As well as describing the geology and tectonics of the area studied, we give an overview of underwater sediments, neotectonics, and some phenomena of history and development of the Baikal, Khubsugul, Chargytai, and Tore-Chol Lakes basins of the Baikal-Tuva region. It is suggested that these lakes' evolution was controlled by neotectonic processes, modern seismic activity, and global climate changes.

A Long, Long Time Ago: Student Perceptions of Geologic Time Using a 45.6-foot-long Timeline

NASA Astrophysics Data System (ADS)

Gehman, J. R.; Johnson, E. A.

2008-12-01

In this study we investigated preconceptions of geologic time held by students in five large (50-115 students each) sections of introductory geology and Earth science courses. Students were randomly divided into groups of eleven individuals, and each group was assigned a separate timeline made from a roll of adding machine paper. Students were encouraged to work as a group to place the eleven geological or biological events where they thought they should belong on their timeline based only on their previous knowledge of geologic time. Geologic events included "Oldest Known Earth Rock" and "The Colorado River Begins to Form the Grand Canyon" while biological events included such milestones as "First Fish," "Dinosaurs go Extinct," and "First Modern Humans." Students were asked in an anonymous survey how they decided to place the events on the timeline in this initial exercise. After the eleven event cards were clipped to the timeline and marks were made to record the initial location of each event, students returned to the classroom and were provided with a scale and the correct dates for the events. Each paper timeline was 45.6 ft. long to represent the 4.56 billion years of Earth history (each one-foot-wide floor tile in the hallways outside the classroom equals 100 million years). Student then returned to their timelines and moved the event cards to the correct locations. At the end of the exercise, survey questions and the paper timelines with the markings of the original position of geologic events were collected and compiled. Analysis of the timeline data based on previous knowledge revealed that no group of students arranged all of the events in the proper sequence, although several groups misplaced only two events in relative order. Students consistently placed events further back in time than their correct locations based on absolute age dates. The survey revealed that several student groups used one "old" event such as the "First Dinosaurs Appear" or "Oldest Known Earth Rock" as a marker from which they based relative placement of other events on the timeline. The most recent events including "First Modern Humans" showed the greatest percentage error of placement.

Geologic Map and Map Database of Eastern Sonoma and Western Napa Counties, California

USGS Publications Warehouse

Graymer, R.W.; Brabb, E.E.; Jones, D.L.; Barnes, J.; Nicholson, R.S.; Stamski, R.E.

2007-01-01

Introduction This report contains a new 1:100,000-scale geologic map, derived from a set of geologic map databases (Arc-Info coverages) containing information at 1:62,500-scale resolution, and a new description of the geologic map units and structural relations in the map area. Prepared as part of the San Francisco Bay Region Mapping Project, the study area includes the north-central part of the San Francisco Bay region, and forms the final piece of the effort to generate new, digital geologic maps and map databases for an area which includes Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Santa Cruz, Solano, and Sonoma Counties. Geologic mapping in Lake County in the north-central part of the map extent was not within the scope of the Project. The map and map database integrates both previously published reports and new geologic mapping and field checking by the authors (see Sources of Data index map on the map sheet or the Arc-Info coverage eswn-so and the textfile eswn-so.txt). This report contains new ideas about the geologic structures in the map area, including the active San Andreas Fault system, as well as the geologic units and their relations. Together, the map (or map database) and the unit descriptions in this report describe the composition, distribution, and orientation of geologic materials and structures within the study area at regional scale. Regional geologic information is important for analysis of earthquake shaking, liquifaction susceptibility, landslide susceptibility, engineering materials properties, mineral resources and hazards, as well as groundwater resources and hazards. These data also assist in answering questions about the geologic history and development of the California Coast Ranges.

A Comparison of Geodetic and Geologic Rates Prior to Large Strike-Slip Earthquakes: A Diversity of Earthquake-Cycle Behaviors?

NASA Astrophysics Data System (ADS)

Dolan, James F.; Meade, Brendan J.

2017-12-01

Comparison of preevent geodetic and geologic rates in three large-magnitude (Mw = 7.6-7.9) strike-slip earthquakes reveals a wide range of behaviors. Specifically, geodetic rates of 26-28 mm/yr for the North Anatolian fault along the 1999 MW = 7.6 Izmit rupture are ˜40% faster than Holocene geologic rates. In contrast, geodetic rates of ˜6-8 mm/yr along the Denali fault prior to the 2002 MW = 7.9 Denali earthquake are only approximately half as fast as the latest Pleistocene-Holocene geologic rate of ˜12 mm/yr. In the third example where a sufficiently long pre-earthquake geodetic time series exists, the geodetic and geologic rates along the 2001 MW = 7.8 Kokoxili rupture on the Kunlun fault are approximately equal at ˜11 mm/yr. These results are not readily explicable with extant earthquake-cycle modeling, suggesting that they may instead be due to some combination of regional kinematic fault interactions, temporal variations in the strength of lithospheric-scale shear zones, and/or variations in local relative plate motion rate. Whatever the exact causes of these variable behaviors, these observations indicate that either the ratio of geodetic to geologic rates before an earthquake may not be diagnostic of the time to the next earthquake, as predicted by many rheologically based geodynamic models of earthquake-cycle behavior, or different behaviors characterize different fault systems in a manner that is not yet understood or predictable.

Tiny timekeepers witnessing high-rate exhumation processes.

PubMed

Zhong, Xin; Moulas, Evangelos; Tajčmanová, Lucie

2018-02-02

Tectonic forces and surface erosion lead to the exhumation of rocks from the Earth's interior. Those rocks can be characterized by many variables including peak pressure and temperature, composition and exhumation duration. Among them, the duration of exhumation in different geological settings can vary by more than ten orders of magnitude (from hours to billion years). Constraining the duration is critical and often challenging in geological studies particularly for rapid magma ascent. Here, we show that the time information can be reconstructed using a simple combination of laser Raman spectroscopic data from mineral inclusions with mechanical solutions for viscous relaxation of the host. The application of our model to several representative geological settings yields best results for short events such as kimberlite magma ascent (less than ~4,500 hours) and a decompression lasting up to ~17 million years for high-pressure metamorphic rocks. This is the first precise time information obtained from direct microstructural observations applying a purely mechanical perspective. We show an unprecedented geological value of tiny mineral inclusions as timekeepers that contributes to a better understanding on the large-scale tectonic history and thus has significant implications for a new generation of geodynamic models.

Structural lineaments of Gaspe from ERTS imagery

NASA Technical Reports Server (NTRS)

Steffensen, R.

1973-01-01

A test study was conducted to assess the value of ERTS images for mapping geologic features of the Gaspe Peninsula, Quebec. The specific objectives of the study were: 1) to ascertain the best procedure to follow in order to obtain valuable geologic data as a result of interpretation; and 2) to indicate in which way these data could relate to mineral exploration. Of the four spectral bands of the Multispectral scanner, the band from 700 to 800 nanometers, which seems to possess the best informational content for geologic study, was selected for analysis. The original ERTS image at a scale of 1:3,700,000 was enlarged about 15 times and reproduced on film. Geologically meaningful lines, called structural lineaments, were outlined and classified according to five categories: morpho-lithologic boundaries, morpho-lithologic lineaments, fault traces, fracture zones and undefined lineaments. Comparison with the geologic map of Gaspe shows that morpho-lithologic boundaries correspond to contacts between regional stratigraphic units. Morpholithologic lineaments follow bedding trends, whereas fracture traces appear as sets of parallel lineaments, intersecting at high angles the previous category of lineaments. Fault traces mark more precisely the location of faults already mapped and spot the presence of presumable faults, not indicated on the geologic map.

Global geologic mapping of Mars: The western equatorial region

USGS Publications Warehouse

Scott, D.H.

1985-01-01

Global geologic mapping of Mars was originally accomplished following acquisition of orbital spacecraft images from the Mariner 9 mission. The mapping program represented a joint enterprise by the U.S. Geological Survey and other planetary scientists from universities in the United States and Europe. Many of the Mariner photographs had low resolution or poor albedo contrast caused by atmospheric haze and high-sun angles. Some of the early geologic maps reflect these deficiencies in their poor discrimination and subdivision of rock units. New geologic maps made from higher resolution and better quality Viking images also represent a cooperative effort, by geologists from the U.S. Geological Survey, Arizona State University, and the University of London. This second series of global maps consists of three parts: 1) western equatorial region, 2) eastern equatorial region, and 3) north and south polar regions. These maps, at 1:15 million scale, show more than 60 individual rock-stratigraphic units assigned to three Martian time-stratigraphic systems. The first completed map of the series covers the western equatorial region of Mars. Accompanying the map is a description of the sequence and distribution of major tectonic, volcanic, and fluvial episodes as recorded in the stratigraphic record. ?? 1985.

Geologic and topographic maps of the Kabul South 30' x 60' quadrangle, Afghanistan

USGS Publications Warehouse

Bohannon, Robert G.

2010-01-01

This report consists of two map sheets, this pamphlet, and a collection of database files. Sheet 1 is the geologic map with three highly speculative cross sections, and sheet 2 is a topographic map that comprises all the support data for the geologic map. Both maps (sheets 1 and 2) are produced at 1:100,000-scale and are provided in Geospatial PDF format that preserves the georegistration and original layering. The database files include images of the topographic hillshade (shaded relief) and color-topography files used to create the topographic maps, a copy of the Landsat image, and a gray-scale basemap. Vector data from each of the layers that comprise both maps are provided in the form of Arc/INFO shapefiles. Most of the geologic interpretations and all of the topographic data were derived exclusively from images. A variety of image types were used, and each image type corresponds to a unique view of the geology. The geologic interpretations presented here are the result of comparing and contrasting between the various images and making the best uses of the strengths of each image type. A limited amount of fieldwork, in the spring of 2004 and the fall of 2006, was carried out within the quadrangle, but all the war-related dangers present in Afghanistan restricted its scope, duration, and utility. The maps that are included in this report represent works-in-progress in that they are simply intended to be the best possible product for the time available and conditions that exist during the early phases of reconstruction in Afghanistan. This report has been funded by the United States Agency for International Development (USAID) as a part of several broader programs that USAID designed to stimulate growth in the energy and mineral sectors of the Afghan economy. The main objective is to provide maps that will be used by scientists of the Afghan Ministry of Mines, the Afghanistan Geological Survey, and the Afghan Geodesy and Cartography Head Office in their efforts to rebuild the energy and mineral sectors of their economy. The U.S. Geological Survey has also produced a variety of geological, topographic, Landsat natural-color, and Landsat false-color maps covering Afghanistan at the 1:250,000 scale. These maps may be used to compliment the information presented here. For more information about USGS activities in Afghanistan, visit the USGS Projects in Afghanistan Web site at http://afghanistan.cr.usgs.gov/ For scientific questions or comments, please send inquiries to Robert G. Bohannon.

Geologic and Topographic Maps of the Kabul North 30' x 60' Quadrangle, Afghanistan

USGS Publications Warehouse

Bohannon, Robert G.

2010-01-01

This report consists of two map sheets, this pamphlet, and a collection of database files. Sheet 1 is the geologic map with two highly speculative cross sections, and sheet 2 is a topographic map that comprises all the support data for the geologic map. Both maps (sheets 1 and 2) are produced at 1:100,000-scale and are provided in GeoPDF format that preserves the georegistration and original layering. The database files include images of the topographic hillshade (shaded relief) and color-topography files used to create the topographic maps, a copy of the Landsat image, and a gray-scale basemap. Vector data from each of the layers that comprise both maps are provided in the form of Arc/INFO shapefiles. Most of the geologic interpretations and all of the topographic data were derived exclusively from images. A variety of image types were used, and each image type corresponds to a unique view of the geology. The geologic interpretations presented here are the result of comparing and contrasting between the various images and making the best uses of the strengths of each image type. A limited amount of fieldwork, in the spring of 2004 and the fall of 2006, was carried out within the quadrangle, but all the war-related dangers present in Afghanistan restricted its scope, duration, and utility. The maps that are included in this report represent works-in-progress in that they are simply intended to be the best possible product for the time available and conditions that exist during the early phases of reconstruction in Afghanistan. This report has been funded by the United States Agency for International Development (USAID) as a part of several broader programs that USAID designed to stimulate growth in the energy and mineral sectors of the Afghan economy. The main objective is to provide maps that will be used by scientists of the Afghan Ministry of Mines, the Afghanistan Geological Survey, and the Afghan Geodesy and Cartography Head Office in their efforts to rebuild the energy and mineral sectors of their economy. The U.S. Geological Survey has also produced a variety of geological, topographic, Landsat natural-color, and Landsat false-color maps covering Afghanistan at the 1:250,000 scale. These maps may be used to compliment the information presented here. For more information about USGS activities in Afghanistan, visit the USGS Projects in Afghanistan Web site at http://gisdata.usgs.net/Website/Afghan/ For scientific questions or comments, please send inquiries to Robert G. Bohannon.

About the geologic map in the National Atlas of the United States of America

USGS Publications Warehouse

Reed, John C.; Bush, Charles A.

2007-01-01

Introduction The geologic map in the National Atlas of the United States of America shows the age, distribution, and general character of the rocks that underlie the Nation, including Alaska, Hawaii, Puerto Rico, and the Virgin Islands (but excluding other small island possessions). (The National Atlas of the United States can be accessed at URL http://nationalatlas.gov/natlas/Natlasstart.asp.) The map depicts the bedrock that lies immediately beneath soils or surficial deposits except where these deposits are so thick and extensive that the type of bedrock beneath them can only be inferred by deep drilling or geophysical methods, or both. Thus, it does not show the extensive glacial deposits of the North Central and Northeastern States, the deep residuum of the Southeastern and South Central States, the relatively thin alluvium along many major rivers and basins, and extensive eolian deposits on the high plains. However, it does show, in a general way, the thick alluvial deposits along the lower Mississippi River and on the Atlantic and Gulf Coastal Plains, and in the deep basins of the western cordillera. The rocks are classified as either sedimentary, volcanic, plutonic, or metamorphic, and their geologic ages are given in terms using a simplified version of the 1999 Geological Society of America geologic time scale. In some places rocks depicted as sedimentary are interlayered with volcanic rocks, including tuff, volcanic breccia, and volcanic flows. Conversely, many of the rocks shown as volcanic include interlayered sedimentary rocks. Plutonic rocks are classified by age and as granitic, intermediate, mafic, or ultramafic, but no similar classification has been attempted for the volcanic rocks in this version of the map. Where sedimentary or volcanic rocks have been metamorphosed but still retain clear evidence of their depositional age and origin, the extent of the metamorphism is shown by a pattern. Where the metamorphism has been so intense that the rocks bear little resemblance to the rocks from which they were derived, they are mapped as gneiss, but the age given is generally the age of the original rocks. The map in the National Atlas is a generalization of a new geologic map of North America that has recently been published by the Geological Society of America. The original compilation was prepared at a scale of 1:2,500,000 for publication at a scale of 1:5,000,000. This generalized version is intended for viewing at scales between about 1:10,000,000 and 1:7,500,000.

On the upscaling of process-based models in deltaic applications

NASA Astrophysics Data System (ADS)

Li, L.; Storms, J. E. A.; Walstra, D. J. R.

2018-03-01

Process-based numerical models are increasingly used to study the evolution of marine and terrestrial depositional environments. Whilst a detailed description of small-scale processes provides an accurate representation of reality, application on geological timescales is restrained by the associated increase in computational time. In order to reduce the computational time, a number of acceleration methods are combined and evaluated for a schematic supply-driven delta (static base level) and an accommodation-driven delta (variable base level). The performance of the combined acceleration methods is evaluated by comparing the morphological indicators such as distributary channel networking and delta volumes derived from the model predictions for various levels of acceleration. The results of the accelerated models are compared to the outcomes from a series of simulations to capture autogenic variability. Autogenic variability is quantified by re-running identical models on an initial bathymetry with 1 cm added noise. The overall results show that the variability of the accelerated models fall within the autogenic variability range, suggesting that the application of acceleration methods does not significantly affect the simulated delta evolution. The Time-scale compression method (the acceleration method introduced in this paper) results in an increased computational efficiency of 75% without adversely affecting the simulated delta evolution compared to a base case. The combination of the Time-scale compression method with the existing acceleration methods has the potential to extend the application range of process-based models towards geologic timescales.

Excerpts from selected LANDSAT 1 final reports in geology

NASA Technical Reports Server (NTRS)

Short, N. M.; Smith, A.; Baker, R.

1976-01-01

The standard formats for the summaries of selected LANDSAT geological data are presented as checklists. These include: (1) value of LANDSAT data to geology, (2) geologic benefits, (3) follow up studies, (4) cost benefits, (5) optimistic working scales, (6) statistical analysis, and (7) enhancement effects.

Controls on Water Storage, Mixing and Release in a Nested Catchment Set-up with Clean and Mixed Physiographic Characteristics

NASA Astrophysics Data System (ADS)

Pfister, L.; McDonnell, J.; Hissler, C.; Martínez-Carreras, N.; Klaus, J.

2015-12-01

With catchment water storage being only rarely determined, storage dynamics remain largely unknown to date. However, storage bears considerable potential for catchment inter-comparison exercises, as well as it is likely to have an important role in regulating catchment functions. Catchment comparisons across a wide range of environments and scales will help to increase our understanding of relationships between storage dynamics and catchment processes. With respect to the potential of catchment storage for bringing new momentum to catchment classification and catchment processes understanding we currently investigate spatial and temporal variability of dynamic storage in a nested catchment set-up (16 catchments) of the Alzette River basin (Luxembourg, Europe), covering a wide range of geological settings, catchment areas, contrasted landuse, and hydro-meteorological and tracer series. We define catchment storage as the total amount of water stored in a control volume, delimited by the catchment's topographical boundaries and depth of saturated and unsaturated zones. Complementary storage assessments (via input-output dynamics of natural tracers, geographical sounding, groundwater level measurements, soil moisture measurements, hydrometry) are carried out for comparison purposes. In our nested catchment set-up we have (1) assessed dependencies between geology, catchment permeability and winter runoff coefficients, (2) calculated water balance derived catchment storage and mixing potential and quantified how dynamic storage differs between catchments and scales, and (3) examined how stream baseflow dD (as a proxy for baseflow transit time) and integrated flow measures (like the flow duration curve) relate to bedrock geology. Catchments with higher bedrock permeability exhibited larger storage capacities and eventually lower average winter runoff coefficients. Over a time-span of 11 years, all catchments re-produced the same winter runoff coefficients year after year, regardless of their bedrock geology, permeability and winter season storage filling ratios. Ultimately, catchment organisation in our area of interest (i.e. geology, permeability, flowpath length) appeared to have a strong control on winter runoff coefficients, catchment storage and subsequently baseflow dD.

Tectonic Reorganization of the Western Pacific in Eocene Time: Missing Pieces in the Subduction Initiation Puzzle

NASA Astrophysics Data System (ADS)

Bloomer, S. H.; Stern, R. J.

2002-12-01

The initiation of subduction is probably the geologic process most responsible for large-scale changes in the motions and interactions of plates. To the extent that subduction drives mantle convection, the initiation of subduction also drives major changes in the convection of the mantle. The mechanisms of subduction initiation remain, however, obscure, but it is becoming increasingly clear that Eocene sequences in the western Pacific provide an outstanding opportunity to study this phenomenon. The major subduction zones of the western Pacific (Tonga, Mariana, Izu, Bonin) all first produced volcanic products in early Eocene time (55-48 Ma). The similarity of timing and of the characteristics of these margins suggests that there may be a common process involved. There is no evidence in the forearc crust of any of these convergent margins for proximity to a continental margin at the time of initiation. Current models of plate motion (particularly given recent reinterpretations of the Hawaiian hotspot bend) show no major plate reorganization that might have provided excess compressional stress across the western Pacific margins. The only mechanically viable mechanism for subduction initiation in the region appears to be spontaneous failure due to gravitational instability of cold, old oceanic lithosphere. There are a number of geologic and geophysical unknowns in assessing the viability of such spontaneous nucleation. The lithosphere becomes stronger as it ages as well as becoming denser. Failure of such crust to form a nascent subduction zone requires a crustal weakness such as a fault and a mechanism to decrease the bending strength of the plate. Paleomagnetic data and plate reconstructions for both the IBM and the Tonga-Kermedec region provide no clear answer to these issues and in fact conflict with interpretations placing large transform faults at the site of subduction nucleation. The large-scale rotations inferred from those data for the IBM conflict, or at least complicate, geologic observations around the Philippine Sea. We will review the currrent structural, mechanical, and geologic constraints on pre-subduction geometry of the western Pacific and will discuss the most essential problems to be solved if we are to constrain how subduction began in the Pacific in Eocene time.

Rates of CO2 Mineralization in Geological Carbon Storage.

PubMed

Zhang, Shuo; DePaolo, Donald J

2017-09-19

Geologic carbon storage (GCS) involves capture and purification of CO 2 at industrial emission sources, compression into a supercritical state, and subsequent injection into geologic formations. This process reverses the flow of carbon to the atmosphere with the intention of returning the carbon to long-term geologic storage. Models suggest that most of the injected CO 2 will be "trapped" in the subsurface by physical means, but the most risk-free and permanent form of carbon storage is as carbonate minerals (Ca,Mg,Fe)CO 3 . The transformation of CO 2 to carbonate minerals requires supply of the necessary divalent cations by dissolution of silicate minerals. Available data suggest that rates of transformation are highly uncertain and difficult to predict by standard approaches. Here we show that the chemical kinetic observations and experimental results, when they can be reduced to a single cation-release time scale that describes the fractional rate at which cations are released to solution by mineral dissolution, show sufficiently systematic behavior as a function of pH, fluid flow rate, and time that the rates of mineralization can be estimated with reasonable certainty. The rate of mineralization depends on both the abundance (determined by the reservoir rock mineralogy) and the rate at which cations are released from silicate minerals by dissolution into pore fluid that has been acidified with dissolved CO 2 . Laboratory-measured rates and field observations give values spanning 8 to 10 orders of magnitude, but when they are evaluated in the context of a reservoir-scale reactive transport simulation, this range becomes much smaller. The reservoir scale simulations provide limits on the applicable conditions under which silicate mineral dissolution and subsequent carbonate mineral precipitation are likely to occur (pH 4.5 to 6, fluid flow velocity less than 5 m/year, and 50-100 years or more after the start of injection). These constraints lead to estimates of 200 to 2000 years for conversion of 60-90% of injected CO 2 when the reservoir rock has a sufficient volume fraction of divalent cation-bearing silicate minerals and confirms that when reservoir rock mineralogy is not favorable the fraction of CO 2 converted to carbonate minerals is minimal over 10 4 years. A sufficient amount of reactive minerals is typically about 20% by volume. Our approach may allow for rapid evaluation of mineralization potential of subsurface storage reservoirs and illustrates how reservoir scale modeling can be integrated with other observations to address key issues relating to engineering of geologic systems.

Geologic map of the Great Smoky Mountains National Park region, Tennessee and North Carolina

USGS Publications Warehouse

Southworth, Scott; Schultz, Art; Aleinikoff, John N.; Merschat, Arthur J.

2012-01-01

The geology of the Great Smoky Mountains National Park region of Tennessee and North Carolina was studied from 1993 to 2003 as part of a cooperative investigation by the U.S. Geological Survey with the National Park Service (NPS). This work resulted in a 1:100,000-scale geologic map derived from mapping that was conducted at scales of 1:24,000 and 1:62,500. The geologic data are intended to support cooperative investigations with the NPS, the development of a new soil map by the Natural Resources Conservation Service, and the All Taxa Biodiversity Inventory. In response to a request by the NPS, we mapped previously unstudied areas, revised the geology where problems existed, and developed a map database for use in interdisciplinary research, land management, and interpretive programs for park visitors.

Digital Data for the reconnaissance geologic map for the Kuskokwim Bay Region of Southwest Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Hults, Chad P.; Mohadjer, Solmaz; Coonrad, Warren L.; Shew, Nora B.; Labay, Keith A.

2008-01-01

INTRODUCTION The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Laboratory Modelling of Volcano Plumbing Systems: a review

NASA Astrophysics Data System (ADS)

Galland, Olivier; Holohan, Eoghan P.; van Wyk de Vries, Benjamin; Burchardt, Steffi

2015-04-01

Earth scientists have, since the XIX century, tried to replicate or model geological processes in controlled laboratory experiments. In particular, laboratory modelling has been used study the development of volcanic plumbing systems, which sets the stage for volcanic eruptions. Volcanic plumbing systems involve complex processes that act at length scales of microns to thousands of kilometres and at time scales from milliseconds to billions of years, and laboratory models appear very suitable to address them. This contribution reviews laboratory models dedicated to study the dynamics of volcano plumbing systems (Galland et al., Accepted). The foundation of laboratory models is the choice of relevant model materials, both for rock and magma. We outline a broad range of suitable model materials used in the literature. These materials exhibit very diverse rheological behaviours, so their careful choice is a crucial first step for the proper experiment design. The second step is model scaling, which successively calls upon: (1) the principle of dimensional analysis, and (2) the principle of similarity. The dimensional analysis aims to identify the dimensionless physical parameters that govern the underlying processes. The principle of similarity states that "a laboratory model is equivalent to his geological analogue if the dimensionless parameters identified in the dimensional analysis are identical, even if the values of the governing dimensional parameters differ greatly" (Barenblatt, 2003). The application of these two steps ensures a solid understanding and geological relevance of the laboratory models. In addition, this procedure shows that laboratory models are not designed to exactly mimic a given geological system, but to understand underlying generic processes, either individually or in combination, and to identify or demonstrate physical laws that govern these processes. From this perspective, we review the numerous applications of laboratory models to understand the distinct key features of volcanic plumbing systems: dykes, cone sheets, sills, laccoliths, caldera-related structures, ground deformation, magma/fault interactions, and explosive vents. Barenblatt, G.I., 2003. Scaling. Cambridge University Press, Cambridge. Galland, O., Holohan, E.P., van Wyk de Vries, B., Burchardt, S., Accepted. Laboratory modelling of volcanic plumbing systems: A review, in: Breitkreuz, C., Rocchi, S. (Eds.), Laccoliths, sills and dykes: Physical geology of shallow level magmatic systems. Springer.

Geological control of floristic composition in Amazonian forests

PubMed Central

Higgins, Mark A; Ruokolainen, Kalle; Tuomisto, Hanna; Llerena, Nelly; Cardenas, Glenda; Phillips, Oliver L; Vásquez, Rodolfo; Räsänen, Matti

2011-01-01

Aim Conservation and land-use planning require accurate maps of patterns in species composition and an understanding of the factors that control them. Substantial doubt exists, however, about the existence and determinants of large-area floristic divisions in Amazonia. Here we ask whether Amazonian forests are partitioned into broad-scale floristic units on the basis of geological formations and their edaphic properties. Location Western and central Amazonia. Methods We used Landsat imagery and Shuttle Radar Topography Mission (SRTM) digital elevation data to identify a possible floristic and geological discontinuity of over 300 km in northern Peru. We then used plant inventories and soil sampling to document changes in species composition and soil properties across this boundary. Data were obtained from 138 sites distributed along more than 450 km of road and river. On the basis of our findings, we used broad-scale Landsat and SRTM mosaics to identify similar patterns across western and central Amazonia. Results The discontinuity identified in Landsat and SRTM data corresponded to a 15-fold change in soil cation concentrations and an almost total change in plant species composition. This discontinuity appears to be caused by the widespread removal of cation-poor surface sediments by river incision to expose cation-rich sediments beneath. Examination of broad-scale Landsat and SRTM mosaics indicated that equivalent processes have generated a north–south discontinuity of over 1500 km in western Brazil. Due to similarities with our study area, we suggest that this discontinuity represents a chemical and ecological limit between western and central Amazonia. Main conclusions Our findings suggest that Amazonian forests are partitioned into large-area units on the basis of geological formations and their edaphic properties. The evolution of these units through geological time may provide a general mechanism for biotic diversification in Amazonia. These compositional units, moreover, may correspond to broad-scale functional units. The existence of large-area compositional and functional units would suggest that protected-area, carbon sequestration, and other land-use strategies in Amazonia be implemented on a region-by-region basis. The methods described here can be used to map these patterns, and thus enable effective conservation and management of Amazonian forests. PMID:22247585

Preliminary integrated geologic map databases for the United States: Digital data for the reconnaissance bedrock geologic map for the northern Alaska peninsula area, southwest Alaska

USGS Publications Warehouse

,

2006-01-01

he growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Preliminary integrated geologic map databases for the United States: Digital data for the reconnaissance geologic map of the western Aleutian Islands, Alaska

USGS Publications Warehouse

,

2006-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO Exportfiles/ and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Digital data for the geology of the Southern Brooks Range, Alaska

USGS Publications Warehouse

Till, Alison B.; Dumoulin, Julie A.; Harris, Anita G.; Moore, Thomas E.; Bleick, Heather A.; Siwiec, Benjamin; Labay, Keith A.; Wilson, Frederic H.; Shew, Nora B.

2008-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. The files named __geol contain geologic polygons and line (contact) attributes; files named __fold contain fold axes; files named __lin contain lineaments; and files named __dike contain dikes as lines. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Digital Data for the reconnaissance geologic map for Prince William Sound and the Kenai Peninsula, Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Hults, Chad P.; Labay, Keith A.; Shew, Nora B.

2007-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. The files named __geol contain geologic polygons and line (contact) attributes; files named __fold contain fold axes; files named __lin contain lineaments; and files named __dike contain dikes as lines. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Preliminary integrated geologic map databases for the United States: Digital data for the generalized bedrock geologic map, Yukon Flats region, east-central Alaska

USGS Publications Warehouse

Till, Alison B.; Dumoulin, Julie A.; Phillips, Jeffrey D.; Stanley, Richard G.; Crews, Jessie

2006-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Preliminary integrated geologic map databases for the United States: Digital data for the reconnaissance geologic map of the lower Yukon River region, Alaska

USGS Publications Warehouse

,

2006-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

The GPlates Portal: Cloud-Based Interactive 3D Visualization of Global Geophysical and Geological Data in a Web Browser.

PubMed

Müller, R Dietmar; Qin, Xiaodong; Sandwell, David T; Dutkiewicz, Adriana; Williams, Simon E; Flament, Nicolas; Maus, Stefan; Seton, Maria

2016-01-01

The pace of scientific discovery is being transformed by the availability of 'big data' and open access, open source software tools. These innovations open up new avenues for how scientists communicate and share data and ideas with each other and with the general public. Here, we describe our efforts to bring to life our studies of the Earth system, both at present day and through deep geological time. The GPlates Portal (portal.gplates.org) is a gateway to a series of virtual globes based on the Cesium Javascript library. The portal allows fast interactive visualization of global geophysical and geological data sets, draped over digital terrain models. The globes use WebGL for hardware-accelerated graphics and are cross-platform and cross-browser compatible with complete camera control. The globes include a visualization of a high-resolution global digital elevation model and the vertical gradient of the global gravity field, highlighting small-scale seafloor fabric such as abyssal hills, fracture zones and seamounts in unprecedented detail. The portal also features globes portraying seafloor geology and a global data set of marine magnetic anomaly identifications. The portal is specifically designed to visualize models of the Earth through geological time. These space-time globes include tectonic reconstructions of the Earth's gravity and magnetic fields, and several models of long-wavelength surface dynamic topography through time, including the interactive plotting of vertical motion histories at selected locations. The globes put the on-the-fly visualization of massive data sets at the fingertips of end-users to stimulate teaching and learning and novel avenues of inquiry.

The GPlates Portal: Cloud-Based Interactive 3D Visualization of Global Geophysical and Geological Data in a Web Browser

PubMed Central

Müller, R. Dietmar; Qin, Xiaodong; Sandwell, David T.; Dutkiewicz, Adriana; Williams, Simon E.; Flament, Nicolas; Maus, Stefan; Seton, Maria

2016-01-01

The pace of scientific discovery is being transformed by the availability of ‘big data’ and open access, open source software tools. These innovations open up new avenues for how scientists communicate and share data and ideas with each other and with the general public. Here, we describe our efforts to bring to life our studies of the Earth system, both at present day and through deep geological time. The GPlates Portal (portal.gplates.org) is a gateway to a series of virtual globes based on the Cesium Javascript library. The portal allows fast interactive visualization of global geophysical and geological data sets, draped over digital terrain models. The globes use WebGL for hardware-accelerated graphics and are cross-platform and cross-browser compatible with complete camera control. The globes include a visualization of a high-resolution global digital elevation model and the vertical gradient of the global gravity field, highlighting small-scale seafloor fabric such as abyssal hills, fracture zones and seamounts in unprecedented detail. The portal also features globes portraying seafloor geology and a global data set of marine magnetic anomaly identifications. The portal is specifically designed to visualize models of the Earth through geological time. These space-time globes include tectonic reconstructions of the Earth’s gravity and magnetic fields, and several models of long-wavelength surface dynamic topography through time, including the interactive plotting of vertical motion histories at selected locations. The globes put the on-the-fly visualization of massive data sets at the fingertips of end-users to stimulate teaching and learning and novel avenues of inquiry. PMID:26960151

Statistical modeling of the long-range-dependent structure of barrier island framework geology and surface geomorphology

NASA Astrophysics Data System (ADS)

Weymer, Bradley A.; Wernette, Phillipe; Everett, Mark E.; Houser, Chris

2018-06-01

Shorelines exhibit long-range dependence (LRD) and have been shown in some environments to be described in the wave number domain by a power-law characteristic of scale independence. Recent evidence suggests that the geomorphology of barrier islands can, however, exhibit scale dependence as a result of systematic variations in the underlying framework geology. The LRD of framework geology, which influences island geomorphology and its response to storms and sea level rise, has not been previously examined. Electromagnetic induction (EMI) surveys conducted along Padre Island National Seashore (PAIS), Texas, United States, reveal that the EMI apparent conductivity (σa) signal and, by inference, the framework geology exhibits LRD at scales of up to 101 to 102 km. Our study demonstrates the utility of describing EMI σa and lidar spatial series by a fractional autoregressive integrated moving average (ARIMA) process that specifically models LRD. This method offers a robust and compact way of quantifying the geological variations along a barrier island shoreline using three statistical parameters (p, d, q). We discuss how ARIMA models that use a single parameter d provide a quantitative measure for determining free and forced barrier island evolutionary behavior across different scales. Statistical analyses at regional, intermediate, and local scales suggest that the geologic framework within an area of paleo-channels exhibits a first-order control on dune height. The exchange of sediment amongst nearshore, beach, and dune in areas outside this region are scale independent, implying that barrier islands like PAIS exhibit a combination of free and forced behaviors that affect the response of the island to sea level rise.

Developing seismogenic source models based on geologic fault data

USGS Publications Warehouse

Haller, Kathleen M.; Basili, Roberto

2011-01-01

Calculating seismic hazard usually requires input that includes seismicity associated with known faults, historical earthquake catalogs, geodesy, and models of ground shaking. This paper will address the input generally derived from geologic studies that augment the short historical catalog to predict ground shaking at time scales of tens, hundreds, or thousands of years (e.g., SSHAC 1997). A seismogenic source model, terminology we adopt here for a fault source model, includes explicit three-dimensional faults deemed capable of generating ground motions of engineering significance within a specified time frame of interest. In tectonically active regions of the world, such as near plate boundaries, multiple seismic cycles span a few hundred to a few thousand years. In contrast, in less active regions hundreds of kilometers from the nearest plate boundary, seismic cycles generally are thousands to tens of thousands of years long. Therefore, one should include sources having both longer recurrence intervals and possibly older times of most recent rupture in less active regions of the world rather than restricting the model to include only Holocene faults (i.e., those with evidence of large-magnitude earthquakes in the past 11,500 years) as is the practice in tectonically active regions with high deformation rates. During the past 15 years, our institutions independently developed databases to characterize seismogenic sources based on geologic data at a national scale. Our goal here is to compare the content of these two publicly available seismogenic source models compiled for the primary purpose of supporting seismic hazard calculations by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) and the U.S. Geological Survey (USGS); hereinafter we refer to the two seismogenic source models as INGV and USGS, respectively. This comparison is timely because new initiatives are emerging to characterize seismogenic sources at the continental scale (e.g., SHARE in the Euro-Mediterranean, http://www.share-eu.org/; EMME in the Middle East, http://www.emme-gem.org/) and global scale (e.g., GEM, http://www.globalquakemodel.org/; Anonymous 2008). To some extent, each of these efforts is still trying to resolve the level of optimal detail required for this type of compilation. The comparison we provide defines a common standard for consideration by the international community for future regional and global seismogenic source models by identifying the necessary parameters that capture the essence of geological fault data in order to characterize seismogenic sources. In addition, we inform potential users of differences in our usage of common geological/seismological terms to avoid inappropriate use of the data in our models and provide guidance to convert the data from one model to the other (for detailed instructions, see the electronic supplement to this article). Applying our recommendations will permit probabilistic seismic hazard assessment codes to run seamlessly using either seismogenic source input. The USGS and INGV database schema compare well at a first-level inspection. Both databases contain a set of fields representing generalized fault three-dimensional geometry and additional fields that capture the essence of past earthquake occurrences. Nevertheless, there are important differences. When we further analyze supposedly comparable fields, many are defined differently. These differences would cause anomalous results in hazard prediction if one assumes the values are similarly defined. The data, however, can be made fully compatible using simple transformations.

Publications - RI 2001-1A | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS RI 2001-1A Publication Details Title: Bedrock geologic map of the Chulitna region the Chulitna region, southcentral Alaska: Alaska Division of Geological & Geophysical Surveys ; Other Oversized Sheets Sheet 1 Bedrock geologic map of the Chulitna region, southcentral Alaska, scale 1

Romanian contribution to research infrastructure database for EPOS

NASA Astrophysics Data System (ADS)

Ionescu, Constantin; Craiu, Andreea; Tataru, Dragos; Balan, Stefan; Muntean, Alexandra; Nastase, Eduard; Oaie, Gheorghe; Asimopolos, Laurentiu; Panaiotu, Cristian

2014-05-01

European Plate Observation System - EPOS is a long-term plan to facilitate integrated use of data, models and facilities from mainly distributed existing, but also new, research infrastructures for solid Earth Science. In EPOS Preparatory Phase were integrated the national Research Infrastructures at pan European level in order to create the EPOS distributed research infrastructures, structure in which, at the present time, Romania participates by means of the earth science research infrastructures of the national interest declared on the National Roadmap. The mission of EPOS is to build an efficient and comprehensive multidisciplinary research platform for solid Earth Sciences in Europe and to allow the scientific community to study the same phenomena from different points of view, in different time periods and spatial scales (laboratory and field experiments). At national scale, research and monitoring infrastructures have gathered a vast amount of geological and geophysical data, which have been used by research networks to underpin our understanding of the Earth. EPOS promotes the creation of comprehensive national and regional consortia, as well as the organization of collective actions. To serve the EPOS goals, in Romania a group of National Research Institutes, together with their infrastructures, gathered in an EPOS National Consortium, as follows: 1. National Institute for Earth Physics - Seismic, strong motion, GPS and Geomagnetic network and Experimental Laboratory; 2. National Institute of Marine Geology and Geoecology - Marine Research infrastructure and Euxinus integrated regional Black Sea observation and early-warning system; 3. Geological Institute of Romania - Surlari National Geomagnetic Observatory and National lithoteque (the latter as part of the National Museum of Geology) 4. University of Bucharest - Paleomagnetic Laboratory After national dissemination of EPOS initiative other Research Institutes and companies from the potential stakeholders group also show their interest to participate in the EPOS National Consortium.

Better Preserved on Mars than on Earth

NASA Image and Video Library

2017-02-13

In many ways, Mars bears remarkable similarities to Earth, but in some ways it is drastically different. Scientists often use Earth as an example, or analog, to help us to understand the geologic history of the Red Planet. As we continue to study Mars, it is vitally important to remember in what ways it differs from Earth. One very apparent way, readily observed from orbit, has to do with its preservation of numerous craters of all sizes, which are densest in its Southern hemisphere. Earth has comparatively little preserved craters -- about 1,000 to 1,500 times fewer -- due to very active geologic processes, especially involving water. When it comes to impact craters, there are some things that can no longer be observed on Earth, but can be observed on Mars. This color composite shows one such example. It covers a portion of the northern central peak of an unnamed, 20-kilometer crater that contains abundant fragmental bedrock called "breccia." The geological relationships here suggest that these breccias include ones formed by the host crater, and others formed from numerous impacts in the distant past. Because there are fewer craters preserved on Earth, terrestrial central uplifts do not expose bedrock formed by previous craters. It may have been the case in the past, but such craters were destroyed over geologic time. The map is projected here at a scale of 25 centimeters (9.9 inches) per pixel. [The original image scale is 28 centimeters (11 inches) per pixel (with 1 x 1 binning); objects on the order of 82 centimeters (32 inches) across are resolved.] North is up. http://photojournal.jpl.nasa.gov/catalog/PIA21455

Geologic remote sensing study of the Hayden pass-Orient Mine Area, Northern Sangre de Cristo Mountains, Colorado

NASA Technical Reports Server (NTRS)

Wychgram, D. C.

1972-01-01

Remote sensor data from a NASA Convair 990 radar flight and Mission 101 and 105 have been interpreted and evaluated. Based on interpretation of the remote sensor data, a geologic map has been prepared and compared with a second geologic map, prepared from interpretation of both remote sensor data and field data. Comparison of the two maps gives one indication of the usefulness and reliability of the remote sensor data. Color and color infrared photography provided the largest amount of valuable information. Multiband photography was of lesser value and side-looking radar imagery provided no new information that was not available on small scale photography. Thermal scanner imagery proved to be a very specialized remote sensing tool that should be applied to areas of low relief and sparse vegetation where geologic features produce known or suspected thermal contrast. Low sun angle photography may be a good alternative to side-looking radar imagery but must be flown with critical timing.

Geologic Mapping in the Hesperia Planum Region of Mars

NASA Technical Reports Server (NTRS)

Gregg, Tracy K. P.; Crown, David A.

2010-01-01

Hesperia Planum, characterized by a high concentration of mare-type wrinkle ridges and ridge rings, encompasses > 2 million square km in the southern highlands of Mars. The most common interpretation is that the plains were emplaced as "flood" lavas with total thicknesses of <3 km [4-10]. The wrinkle ridges on its surface make Hesperia Planum the type locale for "Hesperian-aged ridged plains" on Mars, and wrinkle-ridge formation occurred in more than one episode. Hesperia Planum s stratigraphic position and crater-retention age define the base of the Hesperian System. However, preliminary results of geologic mapping reveal that the whole of Hesperia Planum is unlikely to be composed of the same materials, emplaced at the same geologic time. To unravel these complexities, we are generating a 1:1.5M-scale geologic map of Hesperia Planum and its surroundings. To date, we have identified 4 distinct plains units within Hesperia Planum and are attempting to determine the nature and relative ages of these materials.

Southern California Earthquake Center Geologic Vertical Motion Database

NASA Astrophysics Data System (ADS)

Niemi, Nathan A.; Oskin, Michael; Rockwell, Thomas K.

2008-07-01

The Southern California Earthquake Center Geologic Vertical Motion Database (VMDB) integrates disparate sources of geologic uplift and subsidence data at 104- to 106-year time scales into a single resource for investigations of crustal deformation in southern California. Over 1800 vertical deformation rate data points in southern California and northern Baja California populate the database. Four mature data sets are now represented: marine terraces, incised river terraces, thermochronologic ages, and stratigraphic surfaces. An innovative architecture and interface of the VMDB exposes distinct data sets and reference frames, permitting user exploration of this complex data set and allowing user control over the assumptions applied to convert geologic and geochronologic information into absolute uplift rates. Online exploration and download tools are available through all common web browsers, allowing the distribution of vertical motion results as HTML tables, tab-delimited GIS-compatible text files, or via a map interface through the Google Maps™ web service. The VMDB represents a mature product for research of fault activity and elastic deformation of southern California.

Insights into soil carbon dynamics across climatic and geologic gradients from time-series and fraction-specific radiocarbon analysis

NASA Astrophysics Data System (ADS)

van der Voort, Tessa Sophia; Hagedorn, Frank; Zell, Claudia; McIntyre, Cameron; Eglinton, Tim

2016-04-01

Understanding the interaction between soil organic matter (SOM) and climatic, geologic and ecological factors is essential for the understanding of potential susceptibility and vulnerability to climate and land use change. Radiocarbon constitutes a powerful tool for unraveling SOM dynamics and is increasingly used in studies of carbon turnover. The complex and inherently heterogeneous nature of SOM renders it challenging to assess the processes that govern SOM stability by solely looking at the bulk signature on a plot-scale level. This project combines bulk radiocarbon measurements on a regional-scale spanning wide climatic and geologic gradients with a more in-depth approach for a subset of locations. For this subset, time-series and carbon pool-specific radiocarbon data has been acquired for both topsoil and deeper soils. These well-studied sites are part of the Long-Term Forest Ecosystem Research (LWF) program of the Swiss Federal Institute for Forest, Snow and Landscape research (WSL). Statistical analysis was performed to examine relationships of radiocarbon signatures with variables such as temperature, precipitation and elevation. Bomb-curve modeling was applied determine carbon turnover using time-series data. Results indicate that (1) there is no significant correlation between Δ14C signature and environmental conditions except a weak positive correlation with mean annual temperature, (2) vertical gradients in Δ14C signatures in surface and deeper soils are highly similar despite covering disparate soil-types and climatic systems, and (3) radiocarbon signatures vary significantly between time-series samples and carbon pools. Overall, this study provides a uniquely comprehensive dataset that allows for a better understanding of links between carbon dynamics and environmental settings, as well as for pool-specific and long-term trends in carbon (de)stabilization.

Geologic Mapping of V-19

NASA Technical Reports Server (NTRS)

Martin, P.; Stofan, E. R.; Guest, J. E.

2009-01-01

A geologic map of the Sedna Planitia (V-19) quadrangle is being completed at the 1:5,000,000 scale as part of the NASA Planetary Geologic Mapping Program, and will be submitted for review by September 2009.

Preliminary Geologic Map of the Cook Inlet Region, Alaska-Including Parts of the Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia, Mount Katmai, and Afognak 1:250,000-scale Quadrangles

USGS Publications Warehouse

Wilson, Frederic H.; Hults, Chad P.; Schmoll, Henry R.; Haeussler, Peter J.; Schmidt, Jeanine M.; Yehle, Lynn A.; Labay, Keith A.; Shew, Nora B.

2009-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. The files named __geol contain geologic polygons and line (contact) attributes; files named __fold contain fold axes; files named __lin contain lineaments; and files named __dike contain dikes as lines. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Elevations and distances in the United States

USGS Publications Warehouse

,

1991-01-01

The information in this booklet was compiled to answer inquiries received by the U.S. Geological Survey from students; teachers; writers; editors; publishers of encyclopedias, almanacs, and other reference books; and people in many other fields of work. The elevations of features and distances between points in the United States were determined from surveys and topographic maps of the U.S. Geological Survey or obtained from other sources. In most cases, the elevations were determined from surveys and from 1:24,000- and 1:25,000-scale, 7.5-minute topographic quadrangle maps. In Alaska, information was taken from 1:63,360-scale, 15-minute topographic quadrangle maps. In a few cases, data were obtained from older, 1:62,500-scale, 15-minute maps; these maps are being replaced with larger-scale 7.5-minute coverage. Further information about U.S. Geological Survey products can be obtained from: U.S. Geological Survey, Earth Science Information Center, 507 National Center, Reston, VA 22092 or phone 703-860-6045.

Ground-water recharge in the arid and semiarid southwestern United States - Climatic and geologic framework: Chapter A in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Stonestrom, David A.; Harrill, James R.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Niño and Pacific Decadal Oscillations strongly but irregularly control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of multidecadal droughts unlike any in the modern instrumental record. Anthropogenically induced climate change likely will reduce ground-water recharge through diminished snowpack at higher elevations, and perhaps through increased drought. Future changes in El Niño and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Land-use modifications influence ground-water recharge directly through vegetation, irrigation, and impermeable area, and indirectly through climate change. High ranges bounding the study area—the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east—provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive Paleozoic aquifers in mountainous recharge areas, and distinct modes of recharge in the Colorado Plateau and Basin and Range subregions.

Triton Blushes: A Clue to Global Warming?

NASA Technical Reports Server (NTRS)

Buratti, B. J.; Hicks, M. D.; Newburn, R. L., Jr.

1998-01-01

The large Neptunian satellite Triton is a geologically active body that apparently undergoes complex seasonal changes in its 165 year journey around the sun. Because it is the vehicle for the seasonal transport of volatiles, Triton's atmosphere is expected to undergo large changes in temperature and pressure on a time scale of decades.

An Introductory-Geology Exercise on the Polar-Reversal Time Scale.

ERIC Educational Resources Information Center

Shea, James Herbert

1986-01-01

Presents a three-part exercise which provides undergraduates with opportunities to work with data related to the earth's magnetic field. Includes student materials for activities in determining the history of the earth's magnetic field, in finding the general pattern of declination, and for looking for a polar reversal history. (ML)

Ripples in the Ripples

NASA Technical Reports Server (NTRS)

2004-01-01

This image taken by the Mars Exploration Rover Opportunity shows the dunes that line the floor of 'Endurance Crater.' Small-scale ripples on top of the larger dune waves suggest that these dunes may have been active in geologically recent times. The image was taken by the rover's panoramic camera on sol 198 (August 14, 2004).

Bedrock geologic map of the Seward Peninsula, Alaska, and accompanying conodont data

USGS Publications Warehouse

Till, Alison B.; Dumoulin, Julie A.; Werdon, Melanie B.; Bleick, Heather A.

2011-01-01

This 1:500,000-scale geologic map depicts the bedrock geology of Seward Peninsula, western Alaska, on the North American side of the Bering Strait. The map encompasses all of the Teller, Nome, Solomon, and Bendeleben 1:250,000-scale quadrangles, and parts of the Shishmaref, Kotzebue, Candle, and Norton Bay 1:250,000-scale quadrangles (sh. 1; sh. 2). The geologic map is presented on Sheet 1. The pamphlet includes an introductory text, detailed unit descriptions, tables of geochronologic data, and an appendix containing conodont (microfossil) data and a text explaining those data. Sheet 2 shows metamorphic and tectonic units, conodont color alteration indices, key metamorphic minerals, and locations of geochronology samples listed in the pamphlet. The map area covers 74,000 km2, an area slightly larger than West Virginia or Ireland.

Recharge and Groundwater Flow Within an Intracratonic Basin, Midwestern United States.

PubMed

Panno, Samuel V; Askari, Zohreh; Kelly, Walton R; Parris, Thomas M; Hackley, Keith C

2018-01-01

The conservative nature of chloride (Cl - ) in groundwater and the abundance of geochemical data from various sources (both published and unpublished) provided a means of developing, for the first time, a representation of the hydrogeology of the Illinois Basin on a basin-wide scale. The creation of Cl - isocons superimposed on plan view maps of selected formations and on cross sections across the Illinois Basin yielded a conceptual model on a basin-wide scale of recharge into, groundwater flow within and through the Illinois Basin. The maps and cross sections reveal the infiltration and movement of freshwater into the basin and dilution of brines within various geologic strata occurring at basin margins and along geologic structures. Cross-formational movement of brines is also seen in the northern part of the basin. The maps and cross sections also show barriers to groundwater movement created by aquitards resulting in areas of apparent isolation/stagnation of concentrated brines within the basin. The distribution of Cl - within the Illinois Basin suggests that the current chemical composition of groundwater and distribution of brines within the basin is dependent on five parameters: (1) presence of bedrock exposures along basin margins; (2) permeability of geologic strata and their distribution relative to one another; (3) presence or absence of major geologic structures; (4) intersection of major waterways with geologic structures, basin margins, and permeable bedrock exposures; and (5) isolation of brines within the basin due to aquitards, inhomogeneous permeability, and, in the case of the deepest part of the basin, brine density effects. © 2017, National Ground Water Association.

Relative Time-scale for Channeling Events Within Chaotic Terrains, Margaritifer Sinus, Mars

NASA Technical Reports Server (NTRS)

Janke, D.

1985-01-01

A relative time scale for ordering channel and chaos forming events was constructed for areas within the Margaritifer Sinus region of Mars. Transection and superposition relationships of channels, chaotic terrain, and the surfaces surrounding them were used to create the relative time scale; crater density studies were not used. Channels and chaos in contact with one another were treated as systems. These systems were in turn treated both separately (in order to understand internal relationships) and as members of the suite of Martian erosional forms (in order to produce a combined, master time scale). Channeling events associated with chaotic terrain development occurred over an extended geomorphic period. The channels can be divided into three convenient groups: those that pre-date intercrater plains development post-plains, pre-chasma systems; and those associated with the development of the Vallis Marineris chasmata. No correlations with cyclic climatic changes, major geologic events in other regions on Mars, or triggering phenomena (for example, specific impact events) were found.

3-D imaging of large scale buried structure by 1-D inversion of very early time electromagnetic (VETEM) data

USGS Publications Warehouse

Aydmer, A.A.; Chew, W.C.; Cui, T.J.; Wright, D.L.; Smith, D.V.; Abraham, J.D.

2001-01-01

A simple and efficient method for large scale three-dimensional (3-D) subsurface imaging of inhomogeneous background is presented. One-dimensional (1-D) multifrequency distorted Born iterative method (DBIM) is employed in the inversion. Simulation results utilizing synthetic scattering data are given. Calibration of the very early time electromagnetic (VETEM) experimental waveforms is detailed along with major problems encountered in practice and their solutions. This discussion is followed by the results of a large scale application of the method to the experimental data provided by the VETEM system of the U.S. Geological Survey. The method is shown to have a computational complexity that is promising for on-site inversion.

Barrier island facies models and recognition criteria

NASA Astrophysics Data System (ADS)

Mulhern, J.; Johnson, C. L.

2017-12-01

Barrier island outcrops record transgressive shoreline motion at geologic timescales, providing integral clues to understanding how coastlines respond to rising sea levels. However, barrier island deposits are difficult to recognize. While significant progress has been made in understanding the modern coastal morphodynamics, this insight is not fully leveraged in existing barrier island facies models. Excellent outcrop exposures of the paralic Upper Cretaceous Straight Cliffs Formation of southern Utah provide an opportunity to revise facies models and recognition criteria for barrier island deposits. Preserved barrier islands are composed of three main architectural elements (shorefaces, tidal inlets, and tidal channels) which occur independently or in combination to create larger-scale barrier island deposits. Barrier island shorefaces record progradation, while barrier island tidal inlets record lateral migration, and barrier island tidal channels record aggradation within the tidal inlet. Four facies associations are used to describe and characterize these barrier island architectural elements. Barrier islands occur in association with backarrier fill and internally contain lower and upper shoreface, high-energy upper shoreface, and tidal channel facies. Barrier islands bound lagoons or estuaries, and are distinguished from other shoreface deposits by their internal facies and geometry, association with backbarrier facies, and position within transgressive successions. Tidal processes, in particular tidal inlet migration and reworking of the upper shoreface, also distinguish barrier island deposits. Existing barrier island models highlight the short term heterogeneous and dynamic nature of barrier island systems, yet overlook processes tied to geologic time scales, such as multi-directional motion, erosion, and reworking, and their expressions in preserved barrier island strata. This study uses characteristic outcrop expressions of barrier island successions to exemplify how modern morphodynamic concepts can be combined with geologic time-scale processes to update understanding of ancient barrier island motion and preservation.

A Synthesis of Paleo-Present Stress and Structural Evolution in the Western Anadarko Basin

NASA Astrophysics Data System (ADS)

Gragg, E.; van Wijk, J.

2017-12-01

This research uses a compilation of geological and geophysical data from literature and public databases paired with new seismic, petrophysical and core analyses to deduce the stress and structural histories of the western Anadarko Basin from 1.3 Ga to present day. Paleo-stress fields are vital to understand fold-faulting styles, fracture networks, and the evolution of stratigraphic mechanics through time. These are features that can drastically influence paleo-present fluid migration and accumulations in the subsurface. This work is conducted in an effort to characterize risks to commercial-scale geologic carbon storage via CO2 Enhanced Oil Recovery. We conducted palinspastic restorations on a field-scale fault system using a 3D seismic survey, and also used a fault database produced by the Oklahoma Geological Survey in the analysis. Preliminary results indicate that stress field reorganization occurred multiple times, and is related to a variety of orogenic and epeirogenic events. Sparse age data allow us to constrain at least four of these stress field phases: 1) Mid-Proterozoic crustal grain development; 2) Cambrian Southern Oklahoma Aulacogen; 3) Late Mississippian orogeny, and Pennsylvanian epeirogeny; and 4) Cenozoic Laramide convergence. Stress states influence faulting style and fracture development that can impact CO2 storage and production performance. Future work will explore anthropogenic effects of prior and future production on the stress states and structures at the field scale via the construction of a 3D mechanical earth model coupled to flow simulators. Funding for this project is provided by the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) through the Southwest Partnership on Carbon Sequestration (SWP) under Award No. DE-FC26-05NT42591.

VOSGES, a long and rich geologic history

NASA Astrophysics Data System (ADS)

Dominique, Carteaux; Cyrille, Delangle; Sophie, Demangel

2015-04-01

The study of geology in scientific classes is often too theoretical and abstract for the pupils. How can teachers make the link between some samples of rocks observed in a practical class and the geologic story of the region? There's nothing better than outdoor education to establish a relationship between the rock observed in macroscopic and microscopic scale in the classroom,with the outcrop scale and the landscape scale in the field: all of them are the result of a fascinating geologic history.Our pupils are lucky enough to live at the heart of a modest mountain massif that has a very rich geologic story: the massif from Vosges situated in the east of France. During two expeditions we show the students all the following tectonic processes: Accretion at the scale of the landscape with the Rhenish Ditch (tectonic and volcanic markers) Obductionis observed due to ophiolites found in the massive of Thalhorn (peridotite, gabbro and sedimentary marine rocks of great depth). Collisionis illuminated with numerous sites like the schists of Steige, the phyllite of Villé, the gneisses of Climont. Subductionis captured bystudying the outcrops of magmatic rocks within the continental crust (andesite, diorite, granodiorite). At each of the stops we have the students, from a hand sample, to findits story in a more global context. So the theory becomes reality. A study of thin slides of rocks observed on the ground finishes these exits and so various scales of understanding are approached. The long and rich geologic history of Vosges maybe reconstituted on hundreds of million years, allowing certainly giving another aspect to the living environment of our pupils.

Scarp development in the Valles Marineris

NASA Technical Reports Server (NTRS)

Patton, P. C.

1984-01-01

The scarps along the margins of the Vales Marineris display a complex assemblage of forms that have been related to a variety of mass wasting and sapping processes. These scarp segments display variations in the degree of development of spur and gully topography, the number and density of apparent sapping features and the frequency of large scale landslides which reflect the age, geology and processes of slope development throughout the Valles Marineris. This regional analysis should provide more information on the geologic evolution of the Valles Marineris as well as new insight into the relative importance of different processes in the development of the scarp forms. In order to evaluate the regional variation in scarp form and the influence of time and structure on scarp development geomorphic mapping and morphometric analysis of geologically distinct regions of Valles Marineris is being undertaken.

Martian planetwide crater distributions - Implications for geologic history and surface processes

NASA Technical Reports Server (NTRS)

Soderblom, L. A.; Condit, C. D.; West, R. A.; Herman, B. M.; Kreidler, T. J.

1974-01-01

Three different diameter size ranges are considered in connection with the Martian crater distribution, taking into account small craters from 0.6 to 1.2 km, intermediate-sized craters from 4 to 10 km, and large craters with diameters exceeding 20 km. One of the objectives of the investigation reported is to establish the effects of eolian processes in the modification of craters in the different size ranges. Another objective is concerned with a description of the genetic relationships among the three size ranges of craters. Observables related to the relative age of geologic provinces are to be separated from observables related to geographic variations in eolian transport and deposition. Lunar and Martian cratering histories are compared as a basis for establishing relative and absolute time scales for the geological evolution of Mars.

Large-Scale In-situ Experiments to Determine Geochemical Alterations and Microbial Activities at the Geological Repository

NASA Astrophysics Data System (ADS)

Choung, S.; Francis, A. J.; Um, W.; Choi, S.; Kim, S.; Park, J.; Kim, S.

2013-12-01

The countries that have generated nuclear power have facing problems on the disposal of accumulated radioactive wastes. Geological disposal method has been chosen in many countries including Korea. A safety issue after the closure of geological repository has been raised, because microbial activities lead overpressure in the underground facilities through gas production. In particular, biodegradable organic materials derived from low- and intermediate-level radioactive wastes play important role on microbial activities in the geological repository. This study performed large scale in-situ experiments using organic wastes and groundwater, and investigated geochemical alteration and microbial activities at early stage (~63 days) as representative of the period, after closure of the geological repository. The geochemical alteration controlled significantly the microorganism types and populations. Database of the biogeochemical alteration facilitates prediction of radionuclides' mobility and establishment of remedial strategy against unpredictable accidents and hazards at early stage right after closure of the geological repository.

Geologic Map of the Tucson and Nogales Quadrangles, Arizona (Scale 1:250,000): A Digital Database

USGS Publications Warehouse

Peterson, J.A.; Berquist, J.R.; Reynolds, S.J.; Page-Nedell, S. S.; Digital database by Oland, Gustav P.; Hirschberg, Douglas M.

2001-01-01

The geologic map of the Tucson-Nogales 1:250,000 scale quadrangle (Peterson and others, 1990) was digitized by U.S. Geological Survey staff and University of Arizona contractors at the Southwest Field Office, Tucson, Arizona, in 2000 for input into a geographic information system (GIS). The database was created for use as a basemap in a decision support system designed by the National Industrial Minerals and Surface Processes project. The resulting digital geologic map database can be queried in many ways to produce a variety of geologic maps. Digital base map data files (topography, roads, towns, rivers and lakes, etc.) are not included; they may be obtained from a variety of commercial and government sources. Additionally, point features, such as strike and dip, were not captured from the original paper map and are not included in the database. This database is not meant to be used or displayed at any scale larger than 1:250,000 (for example, 1:100,000 or 1:24,000). The digital geologic map graphics and plot files that are provided in the digital package are representations of the digital database. They are not designed to be cartographic products.

Pressure Variations in Metamorphic Rocks: Implications for the Interpretation of Petrographic Observations

NASA Astrophysics Data System (ADS)

Tajčmanová, Lucie

2014-05-01

Metamorphic petrologists and structural geologists, using direct measurements, bring the only direct observational constrains for validating geodynamic models. Therefore, petrological and structural geological observations are essential for the quality and reproducibility of geodynamic reconstructions and models. One of the important assumptions for geodynamic reconstructions arises from the pressure and temperature estimates in the petrology analysis. Pressure is commonly converted to depth through the equation for lithostatic pressure and so the original position of the rock sample within the Earth's interior can be constrained. The current assumption that the studied sample corresponds to uniform pressure may not be correct, and if so, it has serious implications. Increasing evidence from analytical data shows that pressure is not constant even on a grain scale, posing new challenges because, if ignored, it leads to an incorrect use of petrology data in constraining geodynamic models. Well known examples of the preservation of coesite and diamond in a host mineral like garnet show that high pressure inclusions are preserved during decompression. Tajčmanová et al. (2014) has shown that grain-scale pressure variations can develop and that these pressure variations allow compositional zoning in minerals preserved over geological time scales. A new unconventional barometric method based on equilibrium under pressure variations has been developed . Such pressure variations are also connected with differences in fluid pressure in open systems and can be thus observed at all scales. Tajčmanová L., Podladchikov Y., Powell R., Moulas E., Vrijmoed J. and Connolly J. (2014). Grain scale pressure variations and chemical equilibrium in high-grade metamorphic rocks.Journal of Metamorphic Geology, doi:10.1111/jmg.12066 This work was supported by ERC starting grant 335577 to Lucie Tajcmanova

Planetary Geologic Mapping Handbook - 2010. Appendix

NASA Technical Reports Server (NTRS)

Tanaka, K. L.; Skinner, J. A., Jr.; Hare, T. M.

2010-01-01

Geologic maps present, in an historical context, fundamental syntheses of interpretations of the materials, landforms, structures, and processes that characterize planetary surfaces and shallow subsurfaces. Such maps also provide a contextual framework for summarizing and evaluating thematic research for a given region or body. In planetary exploration, for example, geologic maps are used for specialized investigations such as targeting regions of interest for data collection and for characterizing sites for landed missions. Whereas most modern terrestrial geologic maps are constructed from regional views provided by remote sensing data and supplemented in detail by field-based observations and measurements, planetary maps have been largely based on analyses of orbital photography. For planetary bodies in particular, geologic maps commonly represent a snapshot of a surface, because they are based on available information at a time when new data are still being acquired. Thus the field of planetary geologic mapping has been evolving rapidly to embrace the use of new data and modern technology and to accommodate the growing needs of planetary exploration. Planetary geologic maps have been published by the U.S. Geological Survey (USGS) since 1962. Over this time, numerous maps of several planetary bodies have been prepared at a variety of scales and projections using the best available image and topographic bases. Early geologic map bases commonly consisted of hand-mosaicked photographs or airbrushed shaded-relief views and geologic linework was manually drafted using mylar bases and ink drafting pens. Map publishing required a tedious process of scribing, color peel-coat preparation, typesetting, and photo-laboratory work. Beginning in the 1990s, inexpensive computing, display capability and user-friendly illustration software allowed maps to be drawn using digital tools rather than pen and ink, and mylar bases became obsolete. Terrestrial geologic maps published by the USGS now are primarily digital products using geographic information system (GIS) software and file formats. GIS mapping tools permit easy spatial comparison, generation, importation, manipulation, and analysis of multiple raster image, gridded, and vector data sets. GIS software has also permitted the development of projectspecific tools and the sharing of geospatial products among researchers. GIS approaches are now being used in planetary geologic mapping as well. Guidelines or handbooks on techniques in planetary geologic mapping have been developed periodically. As records of the heritage of mapping methods and data, these remain extremely useful guides. However, many of the fundamental aspects of earlier mapping handbooks have evolved significantly, and a comprehensive review of currently accepted mapping methodologies is now warranted. As documented in this handbook, such a review incorporates additional guidelines developed in recent years for planetary geologic mapping by the NASA Planetary Geology and Geophysics (PGG) Program's Planetary Cartography and Geologic Mapping Working Group's (PCGMWG) Geologic Mapping Subcommittee (GEMS) on the selection and use of map bases as well as map preparation, review, publication, and distribution. In light of the current boom in planetary exploration and the ongoing rapid evolution of available data for planetary mapping, this handbook is especially timely.

Preliminary geologic map of the Townsend 30' x 60' quadrangle, Montana

USGS Publications Warehouse

Reynolds, Mitchell W.; Brandt, Theodore R.

2006-01-01

The geologic map of the Townsend quadrangle, scale 1:100,000, was made as part of the Montana Investigations Project to provide new information on the stratigraphy, structure, and geologic history of this geologically complex area in west-central Montana. The quadrangle encompasses about 4,200 square km (1,640 square mi).

A Biological Perspective on the Meaning of Time

NASA Technical Reports Server (NTRS)

Rothschild, Lynn J.

2014-01-01

We have become impatient waiting for a web page to load, but the first member of our species evolved about 150,000 years ago - a geological instant as brief and as transitory as a text message. The shortest generation time of a bacterium is a sprint at under ten minutes, whereas a 200-year old whale, turtle or tree is not unknown. Life is a phenomenon that integrates processes ranging from the near instantaneous reactions of photosynthesis to the more stately pace of evolution. Here I will elucidate these processes with radically different time scales that go to creating and maintaining the diversity of life on earth, the clocks that nature uses to time them, and how modern biology is being used to alter the natural time scales.

Internet-based information system of digital geological data providing

NASA Astrophysics Data System (ADS)

Yuon, Egor; Soukhanov, Mikhail; Markov, Kirill

2015-04-01

One of the Russian Federal аgency of mineral resources problems is to provide the geological information which was delivered during the field operation for the means of federal budget. This information should be present in the current, conditional form. Before, the leading way of presenting geological information were paper geological maps, slices, borehole diagrams reports etc. Technologies of database construction, including distributed databases, technologies of construction of distributed information-analytical systems and Internet-technologies are intensively developing nowadays. Most of geological organizations create their own information systems without any possibility of integration into other systems of the same orientation. In 2012, specialists of VNIIgeosystem together with specialists of VSEGEI started the large project - creating the system of providing digital geological materials with using modern and perspective internet-technologies. The system is based on the web-server and the set of special programs, which allows users to efficiently get rasterized and vectorised geological materials. These materials are: geological maps of scale 1:1M, geological maps of scale 1:200 000 and 1:2 500 000, the fragments of seamless geological 1:1M maps, structural zoning maps inside the seamless fragments, the legends for State geological maps 1:200 000 and 1:1 000 000, full author's set of maps and also current materials for international projects «Atlas of geological maps for Circumpolar Arctic scale 1:5 000 000» and «Atlas of Geologic maps of central Asia and adjacent areas scale 1:2 500 000». The most interesting and functional block of the system - is the block of providing structured and well-formalized geological vector materials, based on Gosgeolkart database (NGKIS), managed by Oracle and the Internet-access is supported by web-subsystem NGKIS, which is currently based on MGS-Framework platform, developed by VNIIgeosystem. One of the leading elements is the web-service, which realizes the interaction of all parts of the system and controls whole the way of the request from the user to the database and back, adopted to the GeoSciML and EarthResourceML view. The experience of creation the Internet-based information system of digital geological data providing, and also previous works, including the developing of web-service of NGKIS-system, allows to tell, that technological realization of presenting Russian geological-cartographical data with using of international standards is possible. While realizing, it could be some difficulties, associated with geological material depth. Russian informational geological model is more deep and wide, than foreign. This means the main problem of using international standards and formats: Russian geological data presentation is possible only with decreasing the data detalisation. But, such a problem becomes not very important, if the service publishes also Russian vocabularies, not associated with international vocabularies. In this case, the international format could be the interchange format to change data between Russian users. The integration into the international projects reaches developing of the correlation schemes between Russian and foreign classificators and vocabularies.

‘Cape capture’: Geologic data and modeling results suggest the Holocene loss of a Carolina Cape

USGS Publications Warehouse

Thieler, E. Robert; Ashton, Andrew D.

2011-01-01

For more than a century, the origin and evolution of the set of cuspate forelands known as the Carolina Capes—Hatteras, Lookout, Fear, and Romain—off the eastern coast of the United States have been discussed and debated. The consensus conceptual model is not only that these capes existed through much or all of the Holocene transgression, but also that their number has not changed. Here we describe bathymetric, lithologic, seismic, and chronologic data that suggest another cape may have existed between Capes Hatteras and Lookout during the early to middle Holocene. This cape likely formed at the distal end of the Neuse-Tar-Pamlico fluvial system during the early Holocene transgression, when this portion of the shelf was flooded ca. 9 cal (calibrated) kyr B.P., and was probably abandoned by ca. 4 cal kyr B.P., when the shoreline attained its present general configuration. Previously proposed mechanisms for cape formation suggest that the large-scale, rhythmic pattern of the Carolina Capes arose from a hydrodynamic template or the preexisting geologic framework. Numerical modeling, however, suggests that the number and spacing of capes can be dynamic, and that a coast can self-organize in response to a high-angle-wave instability in shoreline shape. In shoreline evolution model simulations, smaller cuspate forelands are subsumed by larger neighbors over millennial time scales through a process of ‘cape capture.’ The suggested former cape in Raleigh Bay represents the first interpreted geological evidence of dynamic abandonment suggested by the self-organization hypothesis. Cape capture may be a widespread process in coastal environments with large-scale rhythmic shoreline features; its preservation in the sedimentary record will vary according to geologic setting, physical processes, and sea-level history.

Digital Geologic Map of the Rosalia 1:100,000 Quadrangle, Washington and Idaho: A Digital Database for the 1990 S.Z. Waggoner Map

USGS Publications Warehouse

Derkey, Pamela D.; Johnson, Bruce R.; Lackaff, Beatrice B.; Derkey, Robert E.

1998-01-01

The geologic map of the Rosalia 1:100,000-scale quadrangle was compiled in 1990 by S.Z. Waggoner of the Washington state Division of Geology and Earth Resources. This data was entered into a geographic information system (GIS) as part of a larger effort to create regional digital geology for the Pacific Northwest. The intent was to provide a digital geospatial database for a previously published black and white paper geologic map. This database can be queried in many ways to produce a variety of geologic maps. Digital base map data files are not included: they may be obtained from a variety of commercial and government sources. This database is not meant to be used or displayed at any scale larger than 1:100,000 (e.g., 1:62,500 or 1:24,000) as it has been somewhat generalized to fit the 1:100,000 scale map. The map area is located in eastern Washington and extends across the state border into western Idaho. This open-file report describes the methods used to convert the geologic map data into a digital format, documents the file structures, and explains how to download the digital files from the U.S. Geological Survey public access World Wide Web site on the Internet. We wish to thank J. Eric Schuster of the Washington Division of Geology and Earth Resources for providing the original stable-base mylar and the funding for it to be scanned. We also thank Dick Blank and Barry Moring of the U.S. Geological Survey for reviewing the manuscript and digital files, respectively.

Lunar Geologic Mapping Program: 2008 Update

NASA Technical Reports Server (NTRS)

Gaddis, L.; Tanaka, K.; Skinner, J.; Hawke, B. R.

2008-01-01

The NASA Lunar Geologic Mapping Program is underway and a mappers handbook is in preparation. This program for systematic, global lunar geologic mapping at 1:2.5M scale incorporates digital, multi-scale data from a wide variety of sources. Many of these datasets have been tied to the new Unified Lunar Control Network 2005 [1] and are available online. This presentation summarizes the current status of this mapping program, the datasets now available, and how they might be used for mapping on the Moon.

Astronomical tuning and carbon isotope stratigraphy of the Maastrichtian in Sopelana and Zumaia (Basque country, N-Spain)

NASA Astrophysics Data System (ADS)

Batenburg, S. J.; Gale, A. S.; Hilgen, F. J.; Hüsing, S. K.; Laskar, J.; Orue-Etxebarria, X.; Sprovieri, M.; Voigt, S.

2012-04-01

Astronomical tuning has led to significant refinement of the Geological Time Scale for the Cenozoic, however the Late Cretaceous time scale still has potential errors of ~0.5 Myr. The Basque sections of Sopelana and Zumaia (N-Spain) provide a high-resolution sedimentary archive encompassing the Maastrichtian up to the Cretaceous/Paleogene boundary. Rhythmic limestone-marl alternations, deposited in a hemipelagic setting, reflect the influence of the periodicities of eccentricity modulated precession. Starting from a K/Pg boundary age of 66.0 Ma, consecutive 405-kyr minima are tuned to the new astronomical solution La2011. This orbital tuning, together with the expression of individual precessional cycles, allows for unprecedented refinement of the Geologic Time Scale for the Maastrichtian with errors <100 kyr. The cyclostratigraphic interpretation is thoroughly tested by time series analysis of magnetic susceptibility and colour reflectance data. A cyclostratigraphic framework and orbital tuning of the Zumaia section has recently been obtained. This is extended further back in time by correlation to the Sopelana section by recognition of orbital patterns and marker beds. The total amount of time represented by the two sections is 5 Myr. The lower boundary falls within chron C32N1n, almost reaching the Campanian/Maastrichtian boundary. Magnetostratigraphic and biostratigraphic data allow for application of the cyclostratigraphic framework worldwide, and comparison to previously published Maastrichtian time scales. Additionally, we present an orbitally tuned bulk carbon isotope curve. The high resolution and large amplitude of shifts in δ13C on the 405-kyr and 1.2-Myr scales enables correlation to deep marine oceanic sites, several sections from the Boreal chalk sea and Italy and, importantly, the Campanian/Maastrichtian boundary GSSP at Tercis, France. This will provide a globally applicable cyclostratigraphic framework for the entire Maastrichtian. We will discuss the implications for the orbital pacing theory of the late Cretaceous climate system. Furthermore we will elaborate on the enigmatic presence of a strong 1.2-Myr cyclicity in lithological and proxy record data and its possible relation to carbon cycle dynamics and/or orbital forcing.

Separation and imaging diffractions by a sparsity-promoting model and subspace trust-region algorithm

NASA Astrophysics Data System (ADS)

Yu, Caixia; Zhao, Jingtao; Wang, Yanfei; Wang, Chengxiang; Geng, Weifeng

2017-03-01

The small-scale geologic inhomogeneities or discontinuities, such as tiny faults, cavities or fractures, generally have spatial scales comparable to or even smaller than the seismic wavelength. Therefore, the seismic responses of these objects are coded in diffractions and an attempt to high-resolution imaging can be made if we can appropriately image them. As the amplitudes of reflections can be several orders of magnitude larger than those of diffractions, one of the key problems of diffraction imaging is to suppress reflections and at the same time to preserve diffractions. A sparsity-promoting method for separating diffractions in the common-offset domain is proposed that uses the Kirchhoff integral formula to enforce the sparsity of diffractions and the linear Radon transform to formulate reflections. A subspace trust-region algorithm that can provide globally convergent solutions is employed for solving this large-scale computation problem. The method not only allows for separation of diffractions in the case of interfering events but also ensures a high fidelity of the separated diffractions. Numerical experiment and field application demonstrate the good performance of the proposed method in imaging the small-scale geological features related to the migration channel and storage spaces of carbonate reservoirs.

Harmonisation of geological data to support geohazard mapping: the case of eENVplus project

NASA Astrophysics Data System (ADS)

Cipolloni, Carlo; Krivic, Matija; Novak, Matevž; Pantaloni, Marco; Šinigoj, Jasna

2014-05-01

In the eENVplus project, which aims is to unlock huge amounts of environmental datamanaged by the national and regional environmental agencies and other public and private organisations, we have developed a cross-border pilot on the geological data harmonisation through the integration and harmonisation of existing services. The pilot analyses the methodology and results of the OneGeology-Europe project, elaborated at the scale of 1:1M, to point out difficulties and unsolved problems highlighted during the project. This preliminary analysis is followed by a comparison of two geological maps provided by the neighbouring countries with the objective to compare and define the geometric and semantic anomalous contacts between geological polygons and lines in the maps. This phase will be followed by a detailed scale geological map analysis aimed to solve the anomalies identified in the previous phase. The two Geological Surveys involved into the pilot will discuss the problems highlighted during this phase. Subsequently the semantic description will be redefined and the geometry of the polygons in geological maps will be redrawn or adjusted according to a lithostratigraphic approach that takes in account the homogeneity of age, lithology, depositional environment and consolidation degree of geological units. The two Geological Surveys have decided to apply the harmonisation process on two different dataset: the first is represented by the Geological Map at the scale of 1:1,000,000, partially harmonised within the OneGeology-Europe project that will be re-aligned with GE INSPIRE data model to produce data and services compliant with INSPIRE target schema. The main target of Geological Surveys is to produce data and web services compliant with the wider international schema, where there are more options to provide data, with specific attributes that are important to obtain the geohazard map as in the case of this pilot project; therefore we have decided to apply GeoSciML 3.2 schema to the dataset that represents Geological Map at the scale of 1:100,000. Within the pilot will be realised two main geohazard examples with a semi-automatized procedure based on a specific tool component integrated in the client: a landslide susceptibility map and a potential flooding map. In this work we want to present the first results obtained with use case geo-processing procedure in the first test phase, where we have developed a dataset compliant with GE INSPIRE to perform the landslide and flooding susceptibility maps.

Publications - RI 2001-1D | Alaska Division of Geological & Geophysical

Science.gov Websites

-geologic map of the Chulitna region, southcentral Alaska, scale 1:63,360 (16.0 M) Digital Geospatial Data Digital Geospatial Data Chulitna region engineering geology Data File Format File Size Info Download

Completion of the 1:1,500,000-Scale Geologic Map of Western Libya Montes and Northwestern Tyrrhena Terra

NASA Astrophysics Data System (ADS)

Huff, A. E.; Skinner, J. A.

2018-06-01

Final progress report on the 1:1,500,000-scale mapping of western Libya Montes and northwestern Tyrrhena Terra. The final unit names, labels, and descriptions are reported as well as the methodology for age determinations and brief geologic history.

43 CFR 3482.3 - Mining operations maps.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and up-to-date maps of the mine, drawn to scales acceptable to the authorized officer. Before a mine... boundary lines; surface buildings; dip of the coal bed(s); true north; map scale; map explanation; location...; geologic conditions as determined from outcrops, drill holes, exploration, or mining; any unusual geologic...

43 CFR 3482.3 - Mining operations maps.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and up-to-date maps of the mine, drawn to scales acceptable to the authorized officer. Before a mine... boundary lines; surface buildings; dip of the coal bed(s); true north; map scale; map explanation; location...; geologic conditions as determined from outcrops, drill holes, exploration, or mining; any unusual geologic...

43 CFR 3482.3 - Mining operations maps.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and up-to-date maps of the mine, drawn to scales acceptable to the authorized officer. Before a mine... boundary lines; surface buildings; dip of the coal bed(s); true north; map scale; map explanation; location...; geologic conditions as determined from outcrops, drill holes, exploration, or mining; any unusual geologic...

Exploratory visualization of earth science data in a Semantic Web context

NASA Astrophysics Data System (ADS)

Ma, X.; Fox, P. A.

2012-12-01

Earth science data are increasingly unlocked from their local 'safes' and shared online with the global science community as well as the average citizen. The European Union (EU)-funded project OneGeology-Europe (1G-E, www.onegeology-europe.eu) is a typical project that promotes works in that direction. The 1G-E web portal provides easy access to distributed geological data resources across participating EU member states. Similar projects can also be found in other countries or regions, such as the geoscience information network USGIN (www.usgin.org) in United States, the groundwater information network GIN-RIES (www.gw-info.net) in Canada and the earth science infrastructure AuScope (www.auscope.org.au) in Australia. While data are increasingly made available online, we currently face a shortage of tools and services that support information and knowledge discovery with such data. One reason is that earth science data are recorded in professional language and terms, and people without background knowledge cannot understand their meanings well. The Semantic Web provides a new context to help computers as well as users to better understand meanings of data and conduct applications. In this study we aim to chain up Semantic Web technologies (e.g., vocabularies/ontologies and reasoning), data visualization (e.g., an animation underpinned by an ontology) and online earth science data (e.g., available as Web Map Service) to develop functions for information and knowledge discovery. We carried out a case study with data of the 1G-E project. We set up an ontology of geological time scale using the encoding languages of SKOS (Simple Knowledge Organization System) and OWL (Web Ontology Language) from W3C (World Wide Web Consortium, www.w3.org). Then we developed a Flash animation of geological time scale by using the ActionScript language. The animation is underpinned by the ontology and the interrelationships between concepts of geological time scale are visualized in the animation. We linked the animation and the ontology to the online geological data of 1G-E project and developed interactive applications. The animation was used to show legends of rock age layers in geological maps dynamically. In turn, these legends were used as control panels to filter out and generalize geospatial features of certain rock ages on map layers. We tested the functions with maps of various EU member states. As a part of the initial results, legends for rock age layers of EU individual national maps were generated respectively, and the functions for filtering and generalization were examined with the map of United Kingdom. Though new challenges are rising in the tests, like those caused by synonyms (e.g., 'Lower Cambrian' and 'Terreneuvian'), the initial results achieved the designed goals of information and knowledge discovery by using the ontology-underpinned animation. This study shows that (1) visualization lowers the barrier of ontologies, (2) integrating ontologies and visualization adds value to online earth science data services, and (3) exploratory visualization supports the procedure of data processing as well as the display of results.

Use of geological mapping tools to improve the hydraulic performance of SuDS.

PubMed

Bockhorn, Britta; Klint, Knud Erik Strøyberg; Jensen, Marina Bergen; Møller, Ingelise

2015-01-01

Most cities in Denmark are situated on low permeable clay rich deposits. These sediments are of glacial origin and range among the most heterogeneous, with hydraulic conductivities spanning several orders of magnitude. This heterogeneity has obvious consequences for the sizing of sustainable urban drainage systems (SuDS). We have tested methods to reveal geological heterogeneity at field scale to identify the most suitable sites for the placement of infiltration elements and to minimize their required size. We assessed the geological heterogeneity of a clay till plain in Eastern Jutland, Denmark measuring the shallow subsurface resistivity with a geoelectrical multi-electrode system. To confirm the resistivity data we conducted a spear auger mapping. The exposed sediments ranged from clay tills over sandy clay tills to sandy tills and correspond well to the geoelectrical data. To verify the value of geological information for placement of infiltration elements we carried out a number of infiltration tests on geologically different areas across the field, and we observed infiltration rates two times higher in the sandy till area than in the clay till area, thus demonstrating that the hydraulic performance of SuDS can be increased considerably and oversizing avoided if field geological heterogeneity is revealed before placing SuDS.

Mars exploration rover geologic traverse by the spirit rover in the plains of Gusev crater, Mars

USGS Publications Warehouse

Crumpler, L.S.; Squyres, S. W.; Arvidson, R. E.; Bell, J.F.; Blaney, D.; Cabrol, N.A.; Christensen, P.R.; DesMarais, D.J.; Farmer, J.D.; Fergason, R.; Golombek, M.P.; Grant, F.D.; Grant, J. A.; Greeley, R.; Hahn, B.; Herkenhoff, K. E.; Hurowitz, J.A.; Knudson, A.T.; Landis, G.A.; Li, R.; Maki, J.; McSween, H.Y.; Ming, D. W.; Moersch, J.E.; Payne, M.C.; Rice, J.W.; Richter, L.; Ruff, S.W.; Sims, M.; Thompson, S.D.; Tosca, N.; Wang, A.; Whelley, P.; Wright, S.P.; Wyatt, M.B.

2005-01-01

The Spirit rover completed a 2.5 km traverse across gently sloping plains on the floor of Gusev crater from its location on the outer rim of Bonneville crater to the lower slopes of the Columbia Hills, Mars. Using the Athena suite of instruments in a transect approach, a systematic series of overlapping panoramic mosaics, remote sensing observations, surface analyses, and trenching operations documented the lateral variations in landforms, geologic materials, and chemistry of the surface throughout the traverse, demonstrating the ability to apply the techniques of field geology by remote rover operations. Textures and shapes of rocks within the plains are consistent with derivation from impact excavation and mixing of the upper few meters of basaltic lavas. The contact between surrounding plains and crater ejecta is generally abrupt and marked by increases in clast abundance and decimeter-scale steps in relief. Basaltic materials of the plains overlie less indurated and more altered rock types at a time-stratigraphic contact between the plains and Columbia Hills that occurs over a distance of one to two meters. This implies that regional geologic contacts are well preserved and that Earth-like field geologic mapping will be possible on Mars despite eons of overturn by small impacts. ?? 2005 Geological Society of America.

Influences of geomorphology and geology on alpine treeline in the American West - More important than climatic influences?

USGS Publications Warehouse

Butler, D.R.; Malanson, G.P.; Walsh, S.J.; Fagre, D.B.

2007-01-01

The spatial distribution and pattern of alpine treeline in the American West reflect the overarching influences of geological history, lithology and structure, and geomorphic processes and landforms, and geologic and geomorphic factors—both forms and processes—can control the spatiotemporal response of the ecotone to climate change. These influences occur at spatial scales ranging from the continental scale to fine scale processes and landforms at the slope scale. Past geomorphic influences, particularly Pleistocene glaciation, have also left their impact on treeline, and treelines across the west are still adjusting to post-Pleistocene conditions within Pleistocene-created landforms. Current fine scale processes include solifluction and changes on relict solifluction and digging by animals. These processes should be examined in detail in future studies to facilitate a better understanding of where individual tree seedlings become established as a primary response of the ecotone to climate change.

Reconnaissance geologic map of Kodiak Island and adjacent islands, Alaska

USGS Publications Warehouse

Wilson, Frederic H.

2013-01-01

Kodiak Island and its adjacent islands, located on the west side of the Gulf of Alaska, contain one of the largest areas of exposure of the flysch and melange of the Chugach terrane of southern Alaska. However, in the past 25 years, only detailed mapping covering small areas in the archipelago has been done. This map and its associated digital files (Wilson and others, 2005) present the best available mapping compiled in an integrated fashion. The map and associated digital files represent part of a systematic effort to release geologic map data for the United States in a uniform manner. The geologic data have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale field mapping. The map data are presented for use at a nominal scale of 1:500,000, although individual datasets (see Wilson and others, 2005) may contain data suitable for use at larger scales.

Geologic Map of the Central Marysvale Volcanic Field, Southwestern Utah

USGS Publications Warehouse

Rowley, Peter D.; Cunningham, Charles G.; Steven, Thomas A.; Workman, Jeremiah B.; Anderson, John J.; Theissen, Kevin M.

2002-01-01

The geologic map of the central Marysvale volcanic field, southwestern Utah, shows the geology at 1:100,000 scale of the heart of one of the largest Cenozoic volcanic fields in the Western United States. The map shows the area of 38 degrees 15' to 38 degrees 42'30' N., and 112 degrees to 112 degrees 37'30' W. The Marysvale field occurs mostly in the High Plateaus, a subprovince of the Colorado Plateau and structurally a transition zone between the complexly deformed Great Basin to the west and the stable, little-deformed main part of the Colorado Plateau to the east. The western part of the field is in the Great Basin proper. The volcanic rocks and their source intrusions in the volcanic field range in age from about 31 Ma (Oligocene) to about 0.5 Ma (Pleistocene). These rocks overlie sedimentary rocks exposed in the mapped area that range in age from Ordovician to early Cenozoic. The area has been deformed by thrust faults and folds formed during the late Mesozoic to early Cenozoic Sevier deformational event, and later by mostly normal faults and folds of the Miocene to Quaternary basin-range episode. The map revises and updates knowledge gained during a long-term U.S. Geological Survey investigation of the volcanic field, done in part because of its extensive history of mining. The investigation also was done to provide framework geologic knowledge suitable for defining geologic and hydrologic hazards, for locating hydrologic and mineral resources, and for an understanding of geologic processes in the area. A previous geologic map (Cunningham and others, 1983, U.S. Geological Survey Miscellaneous Investigations Series I-1430-A) covered the same area as this map but was published at 1:50,000 scale and is obsolete due to new data. This new geologic map of the central Marysvale field, here published as U.S. Geological Survey Geologic Investigations Series I-2645-A, is accompanied by gravity and aeromagnetic maps of the same area and the same scale (Campbell and others, 1999, U.S. Geological Survey Geologic Investigations Series I-2645-B).

Publications - RI 2013-2 | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS RI 2013-2 Publication Details Title: Surficial-geologic map of the Livengood area, central Burns, P.A.C., 2013, Surficial-geologic map of the Livengood area, central Alaska: Alaska Division of Sheet 1 Surficial-geologic map of the Livengood area, central Alaska, scale 1:50,000 (30.0 M) Digital

Assessing the evolutionary history of the class Synurophyceae (Heterokonta) using molecular, morphometric, and paleobiological approaches.

PubMed

Siver, Peter A; Jo, Bok Yeon; Kim, Jong Im; Shin, Woongghi; Lott, Anne Marie; Wolfe, Alexander P

2015-06-01

Heterokont algae of the class Synurophyceae, characterized by distinctive siliceous scales that cover the surface of the cell, are ecologically important in inland waters, yet their evolutionary history remains enigmatic. We explore phylogenetic relationships within this group of algae relative to geologic time, with a focus on evolution of siliceous components. We combined an expansive five-gene and time-calibrated molecular phylogeny of synurophyte algae with an extensive array of fossil specimens from the middle Eocene to infer evolutionary trends within the group. The group originated in the Jurassic approximately 157 million years ago (Ma), with the keystone genera Mallomonas and Synura diverging during the Early Cretaceous at 130 Ma. Mallomonas further splits into two major subclades, signaling the evolution of the V-rib believed to aid in the spacing and organization of scales on the cell covering. Synura also diverges into two primary subclades, separating taxa with forward-projecting spines on the scale from those with a keel positioned on the scale proper. Approximately one third of the fossil species are extinct, whereas the remaining taxa are linked to modern congeners. The taxonomy of synurophytes, which relies extensively on the morphology of the siliceous components, is largely congruent with molecular analyses. Scales of extinct synurophytes were significantly larger than those of modern taxa and may have played a role in their demise. In contrast, many fossil species linked to modern lineages were smaller in the middle Eocene, possibly reflecting growth in the greenhouse climatic state that characterized this geologic interval. © 2015 Botanical Society of America, Inc.

Chemical analyses (raw laboratory data) and locality index maps of the Confederate Gulch area, Broadwater and Meagher Counties, Montana

USGS Publications Warehouse

,

1975-01-01

Analysis of the side looking airborn radar imagery of Massachusetts, Connecticut and Rhode Island indicates that radar shows the topography in great detail. Since bedrock geologic features are frequently expressed in the topography the radar lends itself to geologic interpretation. The radar was studied by comparisons with field mapped geologic data first at a scale of approximately 1:125,000 and then at a scale of 1:500,000. The larger scale comparison revealed that faults, minor faults, joint sets, bedding and foliation attitudes, lithology and lithologic contacts all have a topographic expression interpretable on the imagery. Surficial geologic features were far less visible on the imagery over most of the area studied. The smaller scale comparisons revealed a pervasive, near orthogonal fracture set cutting all types and ages of rock and trending roughly N40?E and N30?W. In certain places the strike of bedding and foliation attitudes and some lithologic Contacts were visible in addition to the fractures. Fracturing in southern New England is apparently far more important than has been previously recognized. This new information, together with the visibility of many bedding and foliation attitudes and lithologic contacts, indicates the importance of radar imagery in improving the geologic interpretation of an area.

GIS representation of coal-bearing areas in Antarctica

USGS Publications Warehouse

Merrill, Matthew D.

2016-03-11

Understanding the distribution of coal-bearing geologic units in Antarctica provides information that can be used in sedimentary, geomorphological, paleontological, and climatological studies. This report is a digital compilation of information on Antarctica’s coal-bearing geologic units found in the literature. It is intended to be used in small-scale spatial geographic information system (GIS) investigations and as a visual aid in the discussion of Antarctica’s coal resources or in other coal-based geologic investigations. Instead of using spatially insignificant point markers to represent large coal-bearing areas, this dataset uses polygons to represent actual coal-bearing lithologic units. Specific locations of coal deposits confirmed from the literature are provided in the attribution for the coal-bearing unit polygons. Coal-sample-location data were used to confirm some reported coal-bearing geology. The age and extent of the coal deposits indicated in the literature were checked against geologic maps ranging from local scale at 1:50,000 to Antarctic continental scale at 1:5,000,000; if satisfactory, the map boundaries were used to generate the polygons for the coal-bearing localities.

Integration of geological remote-sensing techniques in subsurface analysis

USGS Publications Warehouse

Taranik, James V.; Trautwein, Charles M.

1976-01-01

Geological remote sensing is defined as the study of the Earth utilizing electromagnetic radiation which is either reflected or emitted from its surface in wavelengths ranging from 0.3 micrometre to 3 metres. The natural surface of the Earth is composed of a diversified combination of surface cover types, and geologists must understand the characteristics of surface cover types to successfully evaluate remotely-sensed data. In some areas landscape surface cover changes throughout the year, and analysis of imagery acquired at different times of year can yield additional geological information. Integration of different scales of analysis allows landscape features to be effectively interpreted. Interpretation of the static elements displayed on imagery is referred to as an image interpretation. Image interpretation is dependent upon: (1) the geologist's understanding of the fundamental aspects of image formation, and (2.) his ability to detect, delineate, and classify image radiometric data; recognize radiometric patterns; and identify landscape surface characteristics as expressed on imagery. A geologic interpretation integrates surface characteristics of the landscape with subsurface geologic relationships. Development of a geologic interpretation from imagery is dependent upon: (1) the geologist's ability to interpret geomorphic processes from their static surface expression as landscape characteristics on imagery, (2) his ability to conceptualize the dynamic processes responsible for the evolution 6f interpreted geologic relationships (his ability to develop geologic models). The integration of geologic remote-sensing techniques in subsurface analysis is illustrated by development of an exploration model for ground water in the Tucson area of Arizona, and by the development of an exploration model for mineralization in southwest Idaho.

Dealing with Big Numbers: Representation and Understanding of Magnitudes outside of Human Experience

ERIC Educational Resources Information Center

Resnick, Ilyse; Newcombe, Nora S.; Shipley, Thomas F.

2017-01-01

Being able to estimate quantity is important in everyday life and for success in the STEM disciplines. However, people have difficulty reasoning about magnitudes outside of human perception (e.g., nanoseconds, geologic time). This study examines patterns of estimation errors across temporal and spatial magnitudes at large scales. We evaluated the…

Albedo Neutron Dosimetry in a Deep Geological Disposal Repository for High-Level Nuclear Waste.

PubMed

Pang, Bo; Becker, Frank

2017-04-28

Albedo neutron dosemeter is the German official personal neutron dosemeter in mixed radiation fields where neutrons contribute to personal dose. In deep geological repositories for high-level nuclear waste, where neutrons can dominate the radiation field, it is of interest to investigate the performance of albedo neutron dosemeter in such facilities. In this study, the deep geological repository is represented by a shielding cask loaded with spent nuclear fuel placed inside a rock salt emplacement drift. Due to the backscattering of neutrons in the drift, issues concerning calibration of the dosemeter arise. Field-specific calibration of the albedo neutron dosemeter was hence performed with Monte Carlo simulations. In order to assess the applicability of the albedo neutron dosemeter in a deep geological repository over a long time scale, spent nuclear fuel with different ages of 50, 100 and 500 years were investigated. It was found out, that the neutron radiation field in a deep geological repository can be assigned to the application area 'N1' of the albedo neutron dosemeter, which is typical in reactors and accelerators with heavy shielding. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Geologic Mapping of the Marius Quadrangle, the Moon

NASA Technical Reports Server (NTRS)

Gregg, Tracy K. P.; Yingst, Aileen

2008-01-01

The authors seek to construct a 1:2,500,000-scale map of Lunar Quadrangle 10 (LQ10 or the Marius Quadrangle) to address outstanding questions about the Moon's volcanologic history and the role of impact basins in lunar geologic evolution. The selected quadrangle contains Aristarchus plateau and the Marius hills, Reiner Gamma, and Hevelius crater. By generating a geologic map of this region, we can constrain the temporal (and possibly genetic) relations between these features, revealing more information about the Moon's chemical and thermal evolution. Although many of these individual sites have been investigated using Lunar Orbiter, Clementine, Lunar Prospector and Galileo data, no single investigation has yet attempted to constrain the stratigraphic and geologic relationships between these features. Furthermore, we will be able to compare our unit boundaries on the eastern boundary of the proposed map area with those already mapped in the Copernicus Quadrangle. Geologic mapping of the Marius Quadrangle would provide insight to the following questions: the origin, evolution, and distribution of mare volcanism; the timing and effects of the major basin-forming impacts on lunar crustal stratigraphy; and, the Moon's important resources, where they are concentrated, and how they can be accessed.

Resources for Teaching About Evolution from the U.S. Geological Survey

NASA Astrophysics Data System (ADS)

Gordon, L. C.

2001-12-01

As a scientific research agency, the U.S. Geological Survey (USGS) is in an ideal position to provide scientific information and resources to educators. The USGS is not a curriculum developer, nor an expert in pedagogy, yet the USGS does have a wealth of scientific information on subjects such as fossils, geologic time, biological resources and plate tectonics that naturally come in to play in the teaching of evolution. Among USGS resources are the general interest pamphlets Geologic Time, Dinosaurs: Facts And Fiction, Our Changing Continent, and Fossils Rocks, and Time, and its accompanying poster, Fossils Through Time. In addition to printed versions, the pamphlets are available at no cost on the Internet at http://pubs.usgs.gov/gip/. The popular booklet, This Dynamic Earth: The Story of Plate Tectonics, available at http://pubs.usgs.gov/publications/text/dynamic.html, touches on evolution-related subjects such as Alfred Wegener's use of fossils to develop his theory of continental drift, "polar" dinosaur fossils found in Australia, marine fossils in the rocks of the Himalayas, and the use of fossil ages to determine rates of plate motions. Paleontological research at the USGS is highlighted on the Internet at http://geology.er.usgs.gov/paleo/. The web site includes links to technical publications, profiles of scientists, a geologic time scale, a glossary, information on important fossil groups, and a list of non-USGS references on fossils: all very useful to educators. A wealth of biological information and data can be found in the National Biological Information Infrastructure (NBII), a multi-agency collaborative program led by the USGS. In addition to data on the Nation's biological resources, the NBII web site http://www.nbii.gov/ includes a section on systematics and scientific names (helpful for illustrating the evolutionary relationships among living organisms), and links to non-USGS curriculum materials. A fact sheet, Unveiling the NBII as a Teaching Resource, is available at http://www.nbii.gov/about/pubs/factsheet/pdf/education.pdf. Evolution is a key theme in the scope of many USGS research activities. From the evolution of living organisms, to the evolution of geological materials and landforms, the USGS is a rich source of current, accurate, and relevant scientific information for teachers in today's classroom.

Effects of multi-scale environmental characteristics on agricultural stream biota in eastern Wisconsin

USGS Publications Warehouse

Fitzpatrick, F.A.; Scudder, B.C.; Lenz, B.N.; Sullivan, D.J.

2001-01-01

The U.S. Geological Survey examined 25 agricultural streams in eastern Wisconsin to determine relations between fish, invertebrate, and algal metrics and multiple spatial scales of land cover, geologic setting, hydrologic, aquatic habitat, and water chemistry data. Spearman correlation and redundancy analyses were used to examine relations among biotic metrics and environmental characteristics. Riparian vegetation, geologic, and hydrologic conditions affected the response of biotic metrics to watershed agricultural land cover but the relations were aquatic assemblage dependent. It was difficult to separate the interrelated effects of geologic setting, watershed and buffer land cover, and base flow. Watershed and buffer land cover, geologic setting, reach riparian vegetation width, and stream size affected the fish IBI, invertebrate diversity, diatom IBI, and number of algal taxa; however, the invertebrate FBI, percentage of EPT, and the diatom pollution index were more influenced by nutrient concentrations and flow variability. Fish IBI scores seemed most sensitive to land cover in the entire stream network buffer, more so than watershed-scale land cover and segment or reach riparian vegetation width. All but one stream with more than approximately 10 percent buffer agriculture had fish IBI scores of fair or poor. In general, the invertebrate and algal metrics used in this study were not as sensitive to land cover effects as fish metrics. Some of the reach-scale characteristics, such as width/depth ratios, velocity, and bank stability, could be related to watershed influences of both land cover and geologic setting. The Wisconsin habitat index was related to watershed geologic setting, watershed and buffer land cover, riparian vegetation width, and base flow, and appeared to be a good indicator of stream quality. Results from this study emphasize the value of using more than one or two biotic metrics to assess water quality and the importance of environmental characteristics at multiple scales.

Augmenting comprehension of geological relationships by integrating 3D laser scanned hand samples within a GIS environment

NASA Astrophysics Data System (ADS)

Harvey, A. S.; Fotopoulos, G.; Hall, B.; Amolins, K.

2017-06-01

Geological observations can be made on multiple scales, including micro- (e.g. thin section), meso- (e.g. hand-sized to outcrop) and macro- (e.g. outcrop and larger) scales. Types of meso-scale samples include, but are not limited to, rocks (including drill cores), minerals, and fossils. The spatial relationship among samples paired with physical (e.g. granulometric composition, density, roughness) and chemical (e.g. mineralogical and isotopic composition) properties can aid in interpreting geological settings, such as paleo-environmental and formational conditions as well as geomorphological history. Field samples are collected along traverses in the area of interest based on characteristic representativeness of a region, predetermined rate of sampling, and/or uniqueness. The location of a sample can provide relative context in seeking out additional key samples. Beyond labelling and recording of geospatial coordinates for samples, further analysis of physical and chemical properties may be conducted in the field and laboratory. The main motivation for this paper is to present a workflow for the digital preservation of samples (via 3D laser scanning) paired with the development of cyber infrastructure, which offers geoscientists and engineers the opportunity to access an increasingly diverse worldwide collection of digital Earth materials. This paper describes a Web-based graphical user interface developed using Web AppBuilder for ArcGIS for digitized meso-scale 3D scans of geological samples to be viewed alongside the macro-scale environment. Over 100 samples of virtual rocks, minerals and fossils populate the developed geological database and are linked explicitly with their associated attributes, characteristic properties, and location. Applications of this new Web-based geological visualization paradigm in the geosciences demonstrate the utility of such a tool in an age of increasing global data sharing.

Geologic Mapping of V-19, V-28, and V-53

NASA Technical Reports Server (NTRS)

Stofan, E. R.; Martin, P.; Guest, J. E.

2008-01-01

The Sedna Planitia Quadrangle (V-19) extend from 25 deg N - 50 deg N latitude, 330 deg - 0 deg longitude. The quadrangle contains the northern-most portion of western Eistla Regio and the Sedna Planitia lowlands. Geologic maps of Sedna Planitia (V-199), Hecate Chasma (V-28) quadrangles have been completed at the 1:5,000,000 scale as part of the NASA Planetary Geologic Mapping Program. All quadrangles (V-53, V-28 and V-19) have been reviewed at lease once and will be resubmitted. In V-28 and V-53, more plains materials units have been mapped than in previously mapped quadrangles V-46 and V-39. V-19 is more comparable to these latter maps in terms of numbers of plains units. In V-28, all of the plains materials units to the south of the rift have an unusually high concentration of volcanic edifices, which both predate and postdate the units. A similar situation is seen in V-53 and V-19, where small edifice formation is not confined to any specific time period. In the two chasma-related quadrangles, coronae are located along the rift, as well as to the north and the south of the rifts. Coronae in both quadrangles exhibit all forms of corona topographic shapes, including depressions, rimmed depressions, plateaus and domes. In V-28 and V-53, some coronae along the rift do not have much associated volcanism; coronae with the most volcanism in these quadrangles are located at least 500 km off the rifts or on the Themis Regio highland. All three quadrangles have very horizontal stratigraphic columns, as limited contact between units prevents clear age determinations. While this results in the appearance that all units formed at the same time, the use of hachured columns for each unit illustrates the limited nature of our stratigraphic knowledge in these quadrangles, allowing for numerous possible geologic histories. The scale of resurfacing in these quadrangles is on the scale of 100s of kilometers, consistent with the fact that they lie in the most volcanic region of Venus.

Final Stages of the 1:24,000-Scale Geologic Mapping of Basin Deposits Exposed in Hadriacus Cavi, Mars

NASA Astrophysics Data System (ADS)

Skinner, J. A.; Fortezzo, C. M.

2018-06-01

This abstract presents a brief summary of the surface and section characteristics of a type area for stratified deposits exposed in Hadriacus Cavi (78.0°E, –27.3°N), Mars based on 1:24,000 scale geologic mapping and stratigraphic analyses.

Preliminary geologic map of the island of Saipan, Commonwealth of the Northern Mariana Islands

USGS Publications Warehouse

Weary, David J.; Burton, William C.

2011-01-01

This map provides an update and reinterpretation of the geology of the island of Saipan. The geology of the island was previously documented in 1956 in U.S. Geological Survey (USGS) Professional Paper 280-A by Preston E. Cloud, Jr., and others. This report includes a geologic map at a scale of 1:20,000. The fieldwork for this project was performed in 2006 and 2007.

A digital geologic map database for the state of Oklahoma

USGS Publications Warehouse

Heran, William D.; Green, Gregory N.; Stoeser, Douglas B.

2003-01-01

This dataset is a composite of part or all of the 12 1:250,000 scale quadrangles that make up Oklahoma. The result looks like a geologic map of the State of Oklahoma. But it is only an Oklahoma shaped map clipped from the 1:250,000 geologic maps. This is not a new geologic map. No new mapping took place. The geologic information from each quadrangle is available within the composite dataset.

Earth Science Studies in Support of Public Policy Development and Land Stewardship - Headwaters Province, Idaho and Montana

USGS Publications Warehouse

U.S. Geological Survey Headwaters Province Project Team Edited by Lund, Karen

2007-01-01

The USGS Headwaters Province project in western Montana and northern and central Idaho was designed to provide geoscience data and interpretations to Federal Land Management Agencies and to respond to specific concerns of USDA Forest Service Regions 1 and 4. The project has emphasized development of digital geoscience data, GIS analyses, topical studies, and new geologic interpretations. Studies were designed to more completely map lithologic units and determine controls of deformation, magmatism, and mineralizing processes. Topical studies of geologic basement control on these processes include study of regional metallogenic patterns and their relation to the composition and architecture of underlying, unexposed basement; timing of igneous and hydrothermal systems, to identify regionally important metallogenic magmatism; and the geologic setting of Proterozoic strata, to better understand how their sedimentary basins developed and to define the origin of sediment-hosted mineral deposits. Interrelated products of the project are at complementary scales.

Surface and subsurface geologic risk factors to ground water affecting brownfield redevelopment potential.

PubMed

Kaufman, Martin M; Murray, Kent S; Rogers, Daniel T

2003-01-01

A model is created for assessing the redevelopment potential of brownfields. The model is derived from a space and time conceptual framework that identifies and measures the surface and subsurface risk factors present at brownfield sites. The model then combines these factors with a contamination extent multiplier at each site to create an index of redevelopment potential. Results from the application of the model within an urbanized watershed demonstrate clear differences between the redevelopment potential present within five different near-surface geologic units, with those units containing clay being less vulnerable to subsurface contamination. With and without the extent multiplier, the total risk present at the brownfield sites within all the geologic units is also strongly correlated to the actual costs of remediation. Thus, computing the total surface and subsurface risk within a watershed can help guide the remediation efforts at broad geographic scales, and prioritize the locations for redevelopment.

U.S. Geological Survey DLG-3 and Bureau of the Census TIGER data. Development and GIS applications

USGS Publications Warehouse

Batten, Lawrence G.

1990-01-01

The U.S. Geological Survey has been actively developing digital cartographic and geographic data and standards since the early 1970's. One product is Digital Line Graph data, which offer a consistently accurate source of base category geographic information. The Bureau of the Census has combined their Dual Independent Map Encoding data with the Geological Survey's 1:100,000-scale Digital Line Graph data to prepare for the 1990 decennial census. The resulting Topologically Integrated Geographic Encoding and Referencing data offer a wealth of information. A major area of research using these data is in transportation analysis. The attributes associated with Digital Line Graphs can be used to determine the average travel times along each segment. Geographic information system functions can then be used to optimize routes through the network and to generate street name lists. Additional aspects of the subject are discussed.

E-4 Central Kentucky to the Carolina Trough

USGS Publications Warehouse

Rankin, Douglas W.; Dillon, William P.; Black, D.F.B.; Boyer, S.E.; Daniels, David L.; Goldsmith, R.; Grow, J.A.; Horton, J. Wright; Hutchinson, Deborah R.; Klitgord, Kim D.; McDowell, R.C.; Milton, D.J.; Owens, J.P.; Phillips, Jeffrey D.; Bayer, K.C.; Butler, John R.; Elliott, D.W.; Milici, Robert C.

1991-01-01

E-4 is one of eight Geodynamics transects that cross the Atlantic margin of North America between Georgia and Newfoundland. Five of the transects are in the United States and three are in Canada. Transect E-4, which is 110 km wide and more than 1,100 km long, extends from the stable North American craton just west of the Grenville front near Lexington, Kentucky southeastward across Cape Fear, North Carolina, on the Atlantic coast to oceanic crust east of the Blake Spur magnetic anomaly. Like all of the other U.S. Atlantic coast transects, it crosses Cambrian and Jurassic continental margins of North America as well as the Appalachian orogen. The display, based upon published information, portrays the geology, tectonic style and geophysical expression of this segment of the eastern North American continental margin and interprets its Phanerozoic history. The Decade of North American Geology 1983 geologic time scale (Palmer, 1983) is used throughout the display and text.

Crustal-scale geological and thermal models of the Beaufort-Mackenzie Basin, Arctic Canada

NASA Astrophysics Data System (ADS)

Sippel, Judith; Scheck-Wenderoth, Magdalena; Kröger, Karsten; Lewerenz, Björn

2010-05-01

The Beaufort-Mackenzie Basin is a petroliferous province in northwest Arctic Canada and one of the best-known segments of the Arctic Ocean margin due to decades of exploration. Our study is part of the programme MOM (Methane On the Move), which aims to quantify the methane contribution from natural petroleum systems to the atmosphere over geological times. Models reflecting the potential of a sedimentary basin to release methane require well-assessed boundary conditions such as the crustal structure and large-scale temperature variation. We focus on the crustal-scale thermal field of the Beaufort-Mackenzie Basin. This Basin has formed on a post-rift, continental margin which, during the Late Cretaceous and Tertiary, developed into the foreland of the North American Cordilleran foldbelt providing space for the accumulation of up to 16 km of foreland deposits. We present a 3D geological model which integrates the present topography, depth maps of Upper Cretaceous and Tertiary horizons (Kroeger et al., 2008, 2009), tops of formations derived from interpreted 2D reflection seismic lines and 284 boreholes (released by the National Energy Board of Canada), and the sequence stratigraphic framework established by previous studies (e.g. Dixon et al., 1996). To determine the position and geometry of the crust-mantle boundary, an isostatic calculation (Airýs model) is applied to the geological model. We present different crustal-scale models combining isostatic modelling, published deep reflection and refraction seismic lines (e.g. Stephenson et al., 1994; O'Leary et al., 1995), and calculations of the 3D conductive thermal field. References: Dixon, J., 1996. Geological Atlas of the Beaufort-Mackenzie Area, Geological Survey of Canada Miscellaneous Report, 59, Ottawa, 173 pp. Kroeger, K.F., Ondrak, R., di Primio, R. and Horsfield, B., 2008. A three-dimensional insight into the Mackenzie Basin (Canada): Implications for the thermal history and hydrocarbon generation potential of Tertiary deltaic sequences, AAPG Bulletin, 92(2): 225-247. Kroeger, K.F., di Primio, R. and Horsfield, B., (2009). Hydrocarbon flow modeling in complex structures (Mackenzie Basin, Canada), AAPG Bulletin, 93(9): 1-25. O'Leary, D.M., Ellis, R.M., Stephenson, R.A., Lane, L.S. and Zelt, C.A., 1995. Crustal structure of the northern Yukon and Mackenzie Delta, northwestern Canada, Journal of Geophysical Research 100(B7): 9905-9920. Stephenson, R.A., Coflin, K.C., Lane, L.S. and Dietrich, J.R., 1994. Crustal structure and tectonics of the southeastern Beaufort Sea continental margin, Tectonics, 13(2): 389-400.

Geological hazard monitoring system in Georgia

NASA Astrophysics Data System (ADS)

Gaprindashvili, George

2017-04-01

Georgia belongs to one of world's most complex mountainous regions according to the scale and frequency of Geological processes and damage caused to population, farmlands, and Infrastructure facilities. Geological hazards (landslide, debrisflow/mudflow, rockfall, erosion and etc.) are affecting many populated areas, agricultural fields, roads, oil and gas pipes, high-voltage electric power transmission towers, hydraulic structures, and tourist complexes. Landslides occur almost in all geomorphological zones, resulting in wide differentiation in the failure types and mechanisms and in the size-frequency distribution. In Georgia, geological hazards triggered by: 1. Activation of highly intense earthquakes; 2. Meteorological events provoking the disaster processes on the background of global climatic change; 3. Large-scale Human impact on the environment. The prediction and monitoring of Geological Hazards is a very wide theme, which involves different researchers from different spheres. Geological hazard monitoring is essential to prevent and mitigate these hazards. In past years in Georgia several monitoring system, such as Ground-based geodetic techniques, Debrisflow Early Warning System (EWS) were installed on high sensitive landslide and debrisflow areas. This work presents description of Geological hazard monitoring system in Georgia.

Digital geologic map of part of the Thompson Falls 1:100,000 quadrangle, Idaho

USGS Publications Warehouse

Lewis, Reed S.; Derkey, Pamela D.

1999-01-01

The geology of the Thompson Falls 1:100,000 quadrangle, Idaho was compiled by Reed S. Lewis in 1997 onto a 1:100,000-scale greenline mylar of the topographic base map for input into a geographic information system (GIS). The resulting digital geologic map GIS can be queried in many ways to produce a variety of geologic maps. Digital base map data files (topography, roads, towns, rivers and lakes, etc.) are not included: they may be obtained from a variety of commercial and government sources. This database is not meant to be used or displayed at any scale larger than 1:100,000 (e.g., 1:62,500 or 1:24,000). The map area is located in north Idaho. This open-file report describes the geologic map units, the methods used to convert the geologic map data into a digital format, the Arc/Info GIS file structures and relationships, and explains how to download the digital files from the U.S. Geological Survey public access World Wide Web site on the Internet.

Evaluation of geophysical techniques for the detection of paleochannels in the Oakland area of eastern Nebraska as part of the Eastern Nebraska Water Resource Assessment

USGS Publications Warehouse

Abraham, Jared D.; Bedrosian, Paul A.; Asch, Theodore H.; Ball, Lyndsay B.; Cannia, James C.; Phillips, Jeffery D.; Lackey, Susan

2012-01-01

Surface audio-magnetotelluric and time-domain electromagnetic methods achieved sufficient depth of penetration and indicated that the paleochannel was much more complex than the original geological model. Simulated and observed gravity anomalies indicate that imaging sand and gravel aquifers near Oakland, Nebraska, would be difficult due to the complex basement density contrasts. Interpretation of the magnetic data indicates no magnetic sources from geologic units above the bedrock surface. Based upon the analysis and interpretation of the four methods evaluated, we suggest a large-scale survey using a high-powered time-domain airborne system. This is the most efficient and cost-effective path forward for the Eastern Nebraska Water Assessment group to map paleochannels that lie beneath thick clay-rich glacial tills.

Surficial Geologic Map of the Great Smoky Mountains National Park Region, Tennessee and North Carolina

USGS Publications Warehouse

Southworth, Scott; Schultz, Art; Denenny, Danielle; Triplett, James

2004-01-01

The Surficial Geology of the Great Smoky Mountains National Park Region, Tennessee and North Carolina was mapped from 1993 to 2003 under a cooperative agreement between the U.S. Geological Survey (USGS) and the National Park Service (NPS). This 1:100,000-scale digital geologic map was compiled from 2002 to 2003 from unpublished field investigations maps at 1:24,000-scale. The preliminary surficial geologic data and map support cooperative investigations with NPS, the U.S. Natural Resource Conservation Service, and the All Taxa Biodiversity Inventory (http://www.dlia.org/) (Southworth, 2001). Although the focus of our work was within the Park, the geology of the surrounding area is provided for regional context. Surficial deposits document the most recent part of the geologic history of this part of the western Blue Ridge and eastern Tennessee Valley of the Valley and Ridge of the Southern Appalachians. Additionally, there is great variety of surficial materials, which directly affect the different types of soil and associated flora and fauna. The surficial deposits accumulated over tens of millions of years under varied climatic conditions during the Cenozoic era and resulted from a composite of geologic processes.

Geologic map of the Callville Bay Quadrangle, Clark County, Nevada, and Mohave County, Arizona

USGS Publications Warehouse

Anderson, R. Ernest

2003-01-01

Report: 139 Map Scale: 1:24,000 Map Type: colored geologic map A 1:24,000-scale, full-color geologic map and four cross sections of the Callville Bay 7-minute quadrangle in Clark County, Nevada and Mohave County, Arizona. An accompanying text describes 21 stratigraphic units of Paleozoic and Mesozoic sedimentary rocks and 40 units of Cenozoic sedimentary, volcanic, and intrusive rocks. It also discusses the structural setting, framework, and history of the quadrangle and presents a model for its tectonic development.

Chirp subbottom profile data collected in 2015 from the northern Chandeleur Islands, Louisiana

USGS Publications Warehouse

Forde, Arnell S.; DeWitt, Nancy T.; Fredericks, Jake J.; Miselis, Jennifer L.

2018-01-30

As part of the Barrier Island Evolution Research project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted a nearshore geophysical survey around the northern Chandeleur Islands, Louisiana, in September 2015. The objective of the project is to improve the understanding of barrier island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual time scales (1–5 years). Collecting geophysical data can help researchers identify relations between the geologic history of the islands and their present day morphology and sediment distribution. High-resolution geophysical data collected along this rapidly changing barrier island system can provide a unique time-series dataset to further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over medium-term time scales (months to years). Subbottom profile data were collected in September 2015 offshore of the northern Chandeleur Islands, during USGS Field Activity Number 2015-331-FA. Data products, including raw digital chirp subbottom data, processed subbottom profile images, survey trackline map, navigation files, geographic information system data files and formal Federal Geographic Data Committee metadata, and Field Activity Collection System and operation logs are available for download.

Ground-water flow in low permeability environments

USGS Publications Warehouse

Neuzil, Christopher E.

1986-01-01

Certain geologic media are known to have small permeability; subsurface environments composed of these media and lacking well developed secondary permeability have groundwater flow sytems with many distinctive characteristics. Moreover, groundwater flow in these environments appears to influence the evolution of certain hydrologic, geologic, and geochemical systems, may affect the accumulation of pertroleum and ores, and probably has a role in the structural evolution of parts of the crust. Such environments are also important in the context of waste disposal. This review attempts to synthesize the diverse contributions of various disciplines to the problem of flow in low-permeability environments. Problems hindering analysis are enumerated together with suggested approaches to overcoming them. A common thread running through the discussion is the significance of size- and time-scale limitations of the ability to directly observe flow behavior and make measurements of parameters. These limitations have resulted in rather distinct small- and large-scale approaches to the problem. The first part of the review considers experimental investigations of low-permeability flow, including in situ testing; these are generally conducted on temporal and spatial scales which are relatively small compared with those of interest. Results from this work have provided increasingly detailed information about many aspects of the flow but leave certain questions unanswered. Recent advances in laboratory and in situ testing techniques have permitted measurements of permeability and storage properties in progressively “tighter” media and investigation of transient flow under these conditions. However, very large hydraulic gradients are still required for the tests; an observational gap exists for typical in situ gradients. The applicability of Darcy's law in this range is therefore untested, although claims of observed non-Darcian behavior appear flawed. Two important nonhydraulic flow phenomena, osmosis and ultrafiltration, are experimentally well established in prepared clays but have been incompletely investigated, particularly in undisturbed geologic media. Small-scale experimental results form much of the basis for analyses of flow in low-permeability environments which occurs on scales of time and size too large to permit direct observation. Such large-scale flow behavior is the focus of the second part of the review. Extrapolation of small-scale experimental experience becomes an important and sometimes controversial problem in this context. In large flow systems under steady state conditions the regional permeability can sometimes be determined, but systems with transient flow are more difficult to analyze. The complexity of the problem is enhanced by the sensitivity of large-scale flow to the effects of slow geologic processes. One-dimensional studies have begun to elucidate how simple burial or exhumation can generate transient flow conditions by changing the state of stress and temperature and by burial metamorphism. Investigation of the more complex problem of the interaction of geologic processes and flow in two and three dimensions is just beginning. Because these transient flow analyses have largely been based on flow in experimental scale systems or in relatively permeable systems, deformation in response to effective stress changes is generally treated as linearly elastic; however, this treatment creates difficulties for the long periods of interest because viscoelastic deformation is probably significant. Also, large-scale flow simulations in argillaceous environments generally have neglected osmosis and ultrafiltration, in part because extrapolation of laboratory experience with coupled flow to large scales under in situ conditions is controversial. Nevertheless, the effects are potentially quite important because the coupled flow might cause ultra long lived transient conditions. The difficulties associated with analysis are matched by those of characterizing hydrologic conditions in tight environments; measurements of hydraulic head and sampling of pore fluids have been done only rarely because of the practical difficulties involved. These problems are also discussed in the second part of this paper.

Basic Research Needs for Geosciences: Facilitating 21st Century Energy Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

DePaolo, D. J.; Orr, F. M.; Benson, S. M.

2007-06-01

To identify research areas in geosciences, such as behavior of multiphase fluid-solid systems on a variety of scales, chemical migration processes in geologic media, characterization of geologic systems, and modeling and simulation of geologic systems, needed for improved energy systems.

Characterisation and quantification of groundwater-surface water interactions along an alluvial stream using geophysical, hydraulic and tracer methods

NASA Astrophysics Data System (ADS)

Rumph Frederiksen, R.; Rasmussen, K. R.; Christensen, S.

2015-12-01

Qualifying and quantifying water, nutrient and contaminant exchange at the groundwater-surface water interface are becoming increasingly important for water resources management. The objectives of this study are to characterise an alluvial stream using geophysics in addition to traditional geological and geomorphological data and quantify the groundwater seepage to the stream on point-to-reach scale using both hydraulic and tracer methods. We mapped the very shallow subsurface along an alluvial stream using a GCM system (DUALEM421S, an electromagnetic system that can be operated behind a boat or towed behind a motorized vehicle) as well as using geological logs from a large number of old wells. Furthermore we made geomorphological observations through digital maps (old topographical maps and aerial photos) and field observations. We measured stream discharge (quasi-) simultaneously at several positions along the stream using both an Ott-C31 propeller instrument and an Acoustic Doppler Current Profiler instrument. The measurements were made during dry summer periods when baseflow is expected to be the dominating contribution to streamflow. Preliminary findings show that the GCM system reveals small-scale structures not seen with other data types. Furthermore, based on the GCM results and stream discharge results we have identified gaining, losing and zero exchange sections of the stream. During late summer 2015 we will collect additional hydrological data in order to support or modify our preliminary findings. To further investigate the spatial and temporal variations of the groundwater-surface water interactions along the stream we will measure groundwater seepage to the stream using: seepage meter (point-scale) DTS (reach-scale) temperature stick measurements (point-in-space-and-time-scale) temperature loggers installed in the streambed (month-scale) The measurement sites are chosen based on our geophysical, geological, and geomorphological mapping as well as our stream discharge measurements.

Using improved technology for widespread application of a geological carbon sequestration study

NASA Astrophysics Data System (ADS)

Raney, J.

2013-12-01

The Kansas Geological Survey is part of an ongoing collaboration between DOE-NETL, academia, and the petroleum industry to investigate the feasibility of carbon utilization and storage in Kansas. Latest findings in the 25,000 mi2 study area in southern Kansas estimate CO2 storage capacity ranges from 8.8 to 75.5 billion metric tons in a deep Lower Orodovican-age Arbuckle saline aquifer. In addition, an estimated 100 million tonnes of CO2 could be used for extracting additional oil from Kansas' fields, making transitions to carbon management economic. This partnership has a rare opportunity to synchronize abundant, yet previously disseminated knowledge into a cohesive scientific process to optimize sequestration site selection and implementation strategies. Following a thorough characterization, a small-scale CO2 injection of 70,000 tonnes will be implemented in Wellington Field in Sumner County, including a five-plot miscible CO2-EOR flood of a Mississippian reservoir followed by the underlying Arbuckle saline aquifer. Best practices and lessons learned from the field study will improve estimates on CO2 storage capacity, plume migration models, and identify potential leakage pathways to pursue safe and effective geological carbon sequestration at commercial scales. A highly accessible and multifunctional online database is being developed throughout the study that integrates all acquired geological, physical, chemical, and hydrogeologic knowledge. This public database incorporates tens of thousands of data points into easily viewable formats for user downloads. An Interactive Project Map Viewer is a key mechanism to present the scientific research, and will delineate compartment candidates and reservoirs matching reference criteria or user defined attributes. This tool uses a familiar pan and zoom interface to filter regional project data or scale down to detailed digitized information from over 3,300 carefully selected preexisting Kansas wells. A Java-based log analysis program can combine public LAS data with privately owned digital petrophysical information to create refined cross sections with details on lithology and geochemistry. The interactive mapper displays geophysical surveys such as depth and time converted 3D seismic, gravity, magnetic, remote sensing, simulations, regional geologic base layers, and launches web-based well profile tools. Geocelluar models that demonstrate porosity, fault boundaries, seal continuity, and other hydrostratigraphic parameters will illustrate the presence of aquifers and caprocks. Dynamic models will use this input to simulate in situ CO2 plume migration and entrapment mechanisms over time. Additional outreach activities such as core workshops that showcase geological samples, conference presentations to describe technology experiences, and publishing peer-review journal articles will ensure the scientific research is delivered to the general public and useful in academia. Next steps will seek to enhance the current 3D depiction of the subsurface, leading to a direct visual connection between conceptual models and their supporting scientific evidence. Together, these tools aim to unite various industries to perform streamlined data analysis leading to a greater understanding of future geological carbon utilization and storage.

Relationships between plate convergence, the earthquake cycle, and long-term accumulation of net tectonic deformation at island arcs; not so simple as it seems

NASA Astrophysics Data System (ADS)

Taylor, F. W.; Lavier, L. L.; Bevis, M. G.; Thirumalai, K.; Frohlich, C. A.

2012-12-01

Over million-year time scales, what is the relationship between the meter-scale vertical displacements that occur in individual large subduction-zone earthquakes, and the observed topography and geology of island arcs? Because the geographic distribution of vertical displacements associated with the earthquake cycle sometimes mimics topography, it is tempting to assume that vertical deformation simply accrues as the coseismic part of the cycle that is preserved from one event to another. However, our research in the Central New Hebrides and Western Solomon arcs demonstrates that truly permanent tectonic deformation is a step farther removed from the earthquake cycle than we originally assumed. By precisely dating of coral reef terraces we are able to evaluate vertical deformation over time scales of 10,000 to 100,000 years. This analysis indicates that these arcs undergo episodes of hundreds of meters of subsidence and uplift over time scales of tens of thousands of years. Thus what remains in the geologic record is potentially providing invaluable information about more fundamental processes than the elastic earthquake cycle. These longer-term episodes of vertical motion may act in many arcs throughout the world, but evidence of them may be poorly preserved outside of tropical regions where corals along island coastlines provide a record of their occurrence.In our presentation we will describe the tectonic behavior observed in the Central New Hebrides and Western Solomons. We will speculate about some possible mechanisms that explain how the subduction process generates longer-term episodes of subsidence and uplift, and make suggestions about future observations that could better constrain the nature of these processes.

Planetary Geologic Mapping Handbook - 2009

NASA Technical Reports Server (NTRS)

Tanaka, K. L.; Skinner, J. A.; Hare, T. M.

2009-01-01

Geologic maps present, in an historical context, fundamental syntheses of interpretations of the materials, landforms, structures, and processes that characterize planetary surfaces and shallow subsurfaces (e.g., Varnes, 1974). Such maps also provide a contextual framework for summarizing and evaluating thematic research for a given region or body. In planetary exploration, for example, geologic maps are used for specialized investigations such as targeting regions of interest for data collection and for characterizing sites for landed missions. Whereas most modern terrestrial geologic maps are constructed from regional views provided by remote sensing data and supplemented in detail by field-based observations and measurements, planetary maps have been largely based on analyses of orbital photography. For planetary bodies in particular, geologic maps commonly represent a snapshot of a surface, because they are based on available information at a time when new data are still being acquired. Thus the field of planetary geologic mapping has been evolving rapidly to embrace the use of new data and modern technology and to accommodate the growing needs of planetary exploration. Planetary geologic maps have been published by the U.S. Geological Survey (USGS) since 1962 (Hackman, 1962). Over this time, numerous maps of several planetary bodies have been prepared at a variety of scales and projections using the best available image and topographic bases. Early geologic map bases commonly consisted of hand-mosaicked photographs or airbrushed shaded-relief views and geologic linework was manually drafted using mylar bases and ink drafting pens. Map publishing required a tedious process of scribing, color peel-coat preparation, typesetting, and photo-laboratory work. Beginning in the 1990s, inexpensive computing, display capability and user-friendly illustration software allowed maps to be drawn using digital tools rather than pen and ink, and mylar bases became obsolete. Terrestrial geologic maps published by the USGS now are primarily digital products using geographic information system (GIS) software and file formats. GIS mapping tools permit easy spatial comparison, generation, importation, manipulation, and analysis of multiple raster image, gridded, and vector data sets. GIS software has also permitted the development of project-specific tools and the sharing of geospatial products among researchers. GIS approaches are now being used in planetary geologic mapping as well (e.g., Hare and others, 2009). Guidelines or handbooks on techniques in planetary geologic mapping have been developed periodically (e.g., Wilhelms, 1972, 1990; Tanaka and others, 1994). As records of the heritage of mapping methods and data, these remain extremely useful guides. However, many of the fundamental aspects of earlier mapping handbooks have evolved significantly, and a comprehensive review of currently accepted mapping methodologies is now warranted. As documented in this handbook, such a review incorporates additional guidelines developed in recent years for planetary geologic mapping by the NASA Planetary Geology and Geophysics (PGG) Program s Planetary Cartography and Geologic Mapping Working Group s (PCGMWG) Geologic Mapping Subcommittee (GEMS) on the selection and use of map bases as well as map preparation, review, publication, and distribution. In light of the current boom in planetary exploration and the ongoing rapid evolution of available data for planetary mapping, this handbook is especially timely.

Geological and Geographical Atlas of Colorado and portions of adjacent territory

USGS Publications Warehouse

Hayden, Ferdinand Vandeveer; Bien, Julius

1881-01-01

Sheets I-IV are triangulations, drainage, land classification, and geologic maps of Colorado west of longitude 102°, on the scale of 12 miles to the inch. Sheets V-XVI are topographic (contour) and geologic maps of Colorado and adjacent States, between meridians 104° 30' and 109° 30' and parallels 36° 45' and 40° 30', on the scale of 4 miles to the inch. Sheets XVII and XVIII contain three geologic sections across the State, west of the longitude 104° 30'. Sheets XIX and XX are panoramic views of the Pikes Peak group, Sawatch Range, central portion of West Elk Mountains, Twin Lakes, southwestern border of the Mesa Verde, San Juan Mountains, and La Plata Mountains.

Geological and Geographical Atlas of Colorado and portions of adjacent territory

USGS Publications Warehouse

Hayden, Ferdinand Vandeveer; Bien, Julius

1877-01-01

Sheets I-IV are triangulations, drainage, land classification, and geologic maps of Colorado west of longitude 102°, on the scale of 12 miles to the inch. Sheets V-XVI are topographic (contour) and geologic maps of Colorado and adjacent States, between meridians 104° 30' and 109° 30' and parallels 36° 45' and 40° 30', on the scale of 4 miles to the inch. Sheets XVII and XVIII contain three geologic sections across the State, west of the longitude 104° 30'. Sheets XIX and XX are panoramic views of the Pikes Peak group, Sawatch Range, central portion of West Elk Mountains, Twin Lakes, southwestern border of the Mesa Verde, San Juan Mountains, and La Plata Mountains.

Peculiarity of Seismicity in the Balakend-Zagatal Region, Azerbaijan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ismail-Zadeh, Tahir T.

2006-03-23

The study of seismicity in the Balakend-Zagatal region demonstrates a temporal correlation of small events in the region with the moderate events in Caucasus for the time interval of 1980 to 1990. It is shown that the processes resulting in deformation and tectonic movements of main structural elements of the Caucasus region are internal and are not related to large-scale tectonic processes. A week dependence of the regional movements on the large-scale motion of the lithospheric plates and microplates is apparent from another geological and geodetic data as well.

Geology and resource assessment of Costa Rica at 1:500,000 scale; a digital representation of maps of the U.S. Geological Survey's 1987 Folio I-1865

USGS Publications Warehouse

Schruben, Paul G.

1996-01-01

This CD-ROM contains digital versions of the geology and resource assessment maps of Costa Rica originally published by the U.S. Geological Survey (USGS), the Direccion General de Geologia, Minas e Hidrocarburos, and the Universidad de Costa Rica in 1987 at a scale of 1:500,000 in USGS Folio I-1865. The following layers of the map are available on the CD-ROM: geology, favorable domains for selected deposit types, Bouguer gravity, isostatic gravity, mineral deposits, and rock geochemistry sample points. Some of the layers are provided in the following formats: ArcView 1 for Windows and UNIX, ARC/INFO 6.1.2 Export, Digital Line Graph (DLG) Optional, and Drawing Exchange File (DXF). This CD-ROM was produced in accordance with the ISO 9660 and Apple Computer's HFS standards.

Geology and resource assessment of Costa Rica at 1:500,000 scale; a digital representation of maps of the U.S. Geological Survey's 1987 folio I-1865

USGS Publications Warehouse

Schruben, Paul G.

1997-01-01

This CD-ROM contains digital versions of the geology and resource assessment maps of Costa Rica originally published in USGS Folio I-1865 (U.S. Geological Survey, the Direccion General de Geologia, Minas e Hidrocarburos, and the Universidad de Costa Rica, 1987) at a scale of 1:500,000. The following layers are available on the CD-ROM: geology and faults; favorable domains for selected deposit types; Bouguer gravity data; isostatic gravity contours; mineral deposits, prospects, and occurrences; and rock geochemistry sample points. For DOS users, the CD-ROM contains MAPPER, a user-friendly map display program. Some of the maps are also provided in the following additional formats on the CD-ROM: (1) ArcView 1 and 3, (2) ARC/INFO 6.1.2 Export, (3) Digital Line Graph (DLG) Optional, and (4) Drawing Exchange File (DXF.)

The GPlates Portal: Cloud-based interactive 3D and 4D visualization of global geological and geophysical data and models in a browser

NASA Astrophysics Data System (ADS)

Müller, Dietmar; Qin, Xiaodong; Sandwell, David; Dutkiewicz, Adriana; Williams, Simon; Flament, Nicolas; Maus, Stefan; Seton, Maria

2017-04-01

The pace of scientific discovery is being transformed by the availability of 'big data' and open access, open source software tools. These innovations open up new avenues for how scientists communicate and share data and ideas with each other, and with the general public. Here, we describe our efforts to bring to life our studies of the Earth system, both at present day and through deep geological time. The GPlates Portal (portal.gplates.org) is a gateway to a series of virtual globes based on the Cesium Javascript library. The portal allows fast interactive visualization of global geophysical and geological data sets, draped over digital terrain models. The globes use WebGL for hardware-accelerated graphics and are cross-platform and cross-browser compatible with complete camera control. The globes include a visualization of a high-resolution global digital elevation model and the vertical gradient of the global gravity field, highlighting small-scale seafloor fabric such as abyssal hills, fracture zones and seamounts in unprecedented detail. The portal also features globes portraying seafloor geology and a global data set of marine magnetic anomaly identifications. The portal is specifically designed to visualize models of the Earth through geological time. These space-time globes include tectonic reconstructions of the Earth's gravity and magnetic fields, and several models of long-wavelength surface dynamic topography through time, including the interactive plotting of vertical motion histories at selected locations. The portal has been visited over half a million times since its inception in October 2015, as tracked by google analytics, and the globes have been featured in numerous media articles around the world. This demonstrates the high demand for fast visualization of global spatial big data, both for the present-day as well as through geological time. The globes put the on-the-fly visualization of massive data sets at the fingertips of end-users to stimulate teaching and learning and novel avenues of inquiry. This technology offers many future opportunities for providing additional functionality, especially on-the-fly big data analytics. Müller, R.D., Qin, X., Sandwell, D.T., Dutkiewicz, A., Williams, S.E., Flament, N., Maus, S. and Seton, M, 2016, The GPlates Portal: Cloud-based interactive 3D visualization of global geophysical and geological data in a web browser, PLoS ONE 11(3): e0150883. doi:10.1371/ journal.pone.0150883

Self-dissimilar landscapes: Revealing the signature of geologic constraints on landscape dissection via topologic and multi-scale analysis

NASA Astrophysics Data System (ADS)

Danesh-Yazdi, Mohammad; Tejedor, Alejandro; Foufoula-Georgiou, Efi

2017-10-01

Climatic or geologic controls, such as tectonics or glacial drainage, might impose constraints on landscape self-organization resulting in spatial patterns of rivers and valleys which do not obey the typical self-similar relationships found in most landscapes. The goal of this study is to quantify how such geologic constraints express themselves on channel network topology, spatial heterogeneity of drainage patterns, and emergence of preferred scales of landscape dissection. We use as an example a basin located in the Upper Midwestern United States where successive glaciations over the past thousand years have led to a pronounced spatially anisotropic channel network structure which defeats most scaling laws of fluvial landscapes. This is contrasted with another river basin in the North-Central U.S. which has been organized under the absence of major geologic influences and follows a typical self-similar channel network organization. We show how the geologic constraints have imposed a competition for space which is captured in the slope-local drainage density probabilistic structure, in the failure of self-similarity in basin-wide river network topology, and in the length-area scaling relationship being not typical of fluvial landscapes. Via a two-dimensional wavelet analysis and synthesis, we demonstrate the occurrence of a gap in the power spectrum which corresponds to the presence of preferred scales of organization, and characterize them through multi-scale detrending. The developed methodologies can be useful in advancing our geomorphologic understanding of how external controls might manifest themselves in creating a landscape dissection that is outside the norm and how this dissection can be studied objectively for understanding cause and effect.

Geologic map of the Hiller Mountain Quadrangle, Clark County, Nevada, and Mohave County, Arizona

USGS Publications Warehouse

Howard, Keith A.; Hook, Simon; Phelps, Geoffrey A.; Block, Debra L.

2003-01-01

Map Scale: 1:24,000 Map Type: colored geologic map The Hiller Mountains Quadrangle straddles Virgin Canyon in the eastern part of Lake Mead. Proterozoic gneisses and granitoid rocks underlie much of the quadrangle. They are overlain by upper Miocene basin-filling deposits of arkosic conglomerate, basalt, and the overlying Hualapai Limestone. Inception of the Colorado River followed deposition of the Hualapai Limestone and caused incision of the older rocks. Fluvial gravel deposits indicate various courses of the early river across passes through highlands of the Gold Butte-Hiller Mountains-White Hills structural block. Faults and tilted rocks in the quadrangle record tectonic extension that climaxed in middle Miocene time.

Quaternary geophysical framework of the northeastern North Carolina coastal system

USGS Publications Warehouse

Thieler, E.R.; Foster, D.S.; Mallinson, D.M.; Himmelstoss, E.A.; McNinch, J.E.; List, J.H.; Hammar-Klose, E.S.

2013-01-01

The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that mapped the Quaternary geologic framework of the estuaries, barrier islands, and inner continental shelf. This information provides a basis to understand the linkage between geologic framework, physical processes, and coastal evolution at time scales from storm events to millennia. The study area attracts significant tourism to its parks and beaches, contains a number of coastal communities, and supports a local fishing industry, all of which are impacted by coastal change. Knowledge derived from this research program can be used to mitigate hazards and facilitate effective management of this dynamic coastal system.

LONG TERM STABILITY STUDY AT FNAL AND SLAC USING BINP DEVELOPED HYDROSTATIC LEVEL SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seryi, Andrei

2003-05-28

Long term ground stability is essential for achieving the performance goals of the Next Linear Collider. To characterize ground motion on relevant time scales, measurements have been performed at three geologically different locations using a hydrostatic level system developed specifically for these studies. Comparative results from the different sites are presented in this paper.

Historical changes in pool habitats in the Columbia River basin

Treesearch

Bruce A. McIntosh; James R. Sedell; Russell F. Thurow; Sharon E. Clarke; Gwynn L. Chandler

1995-01-01

Knowledge of how stream habitats change over time in natural and human-influenced ecosystems at large, regional scales is currently limited. A historical stream survey (1934-1945) was compared to current surveys to assess changes in pool habitats in the Columbia River basin. Streams from across the basin, representing a wide range of geologies, stream sizes and land-...

Exotic ecosystems: where root disease is not a beneficial component of temperate conifer forests

Treesearch

William J. Otrosina

2003-01-01

Forest tree species and ecosystems ahve evolved under climatic, geological, and biological forces over eons of time. The present flora represents the sum of these selective forces that have acted upon ancestral and modern species. Adaptations to climatic factors, soils, insects, diseases, and a host of disturbance events, operating at a variety of scales, ahve forged...

The interoperability skill of the Geographic Portal of the ISPRA - Geological Survey of Italy

NASA Astrophysics Data System (ADS)

Pia Congi, Maria; Campo, Valentina; Cipolloni, Carlo; Delogu, Daniela; Ventura, Renato; Battaglini, Loredana

2010-05-01

The Geographic Portal of Geological Survey of Italy (ISPRA) available at http://serviziogeologico.apat.it/Portal was planning according to standard criteria of the INSPIRE directive. ArcIMS services and at the same time WMS and WFS services had been realized to satisfy the different clients. For each database and web-services the metadata had been wrote in agreement with the ISO 19115. The management architecture of the portal allow it to encode the clients input and output requests both in ArcXML and in GML language. The web-applications and web-services had been realized for each database owner of Land Protection and Georesources Department concerning the geological map at the scale 1:50.000 (CARG Project) and 1:100.000, the IFFI landslide inventory, the boreholes due Law 464/84, the large-scale geological map and all the raster format maps. The portal thus far published is at the experimental stage but through the development of a new graphical interface achieves the final version. The WMS and WFS services including metadata will be re-designed. The validity of the methodology and the applied standards allow to look ahead to the growing developments. In addition to this it must be borne in mind that the capacity of the new geological standard language (GeoSciML), which is already incorporated in the web-services deployed, will be allow a better display and query of the geological data according to the interoperability. The characteristics of the geological data demand for the cartographic mapping specific libraries of symbols not yet available in a WMS service. This is an other aspect regards the standards of the geological informations. Therefore at the moment were carried out: - a library of geological symbols to be used for printing, with a sketch of system colors and a library for displaying data on video, which almost completely solves the problems of the coverage point and area data (also directed) but that still introduces problems for the linear data (solutions: ArcIMS services from Arcmap projects or a specific SLD implementation for WMS services); - an update of "Guidelines for the supply of geological data" in a short time will be published; - the Geological Survey of Italy is officially involved in the IUGS-CGI working group for the processing and experimentation on the new GeoSciML language with the WMS/WFS services. The availability of geographic informations occurs through the metadata that can be distributed online so that search engines can find them through specialized research. The collected metadata in catalogs are structured in a standard (ISO 19135). The catalogs are a ‘common' interface to locate, view and query data and metadata services, web services and other resources. Then, while working in a growing sector of the environmental knowledgement the focus is to collect the participation of other subjects that contribute to the enrichment of the informative content available, so as to be able to arrive to a real portal of national interest especially in case of disaster management.

Accelerated Weathering of Waste Glass at 90°C with the Pressurized Unsaturated Flow (PUF) Apparatus: Implications for Predicting Glass Corrosion with a Reactive Transport Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, Eric M.; Bacon, Diana H.

2009-09-21

The interest in the long-term durability of waste glass stems from the need to predict radionuclide release rates from the corroding glass over geologic time-scales. Several long-term test methods have been developed to accelerate the glass-water reaction [drip test, vapor hydration test, product consistency test-B, and pressurized unsaturated flow (PUF)]. Currently, the PUF test is the only method that can mimic the unsaturated hydraulic properties expected in a subsurface disposal facility and simultaneously monitor the glass-water reaction. PUF tests are being conducted to accelerate the weathering of glass and validate the model parameters being used to predict long-term glass behavior.more » One dimensional reactive chemical transport simulations of glass dissolution and secondary phase formation during a 1.5-year long PUF experiment was conducted with the subsurface transport over reactive multi-phases (STORM) code. Results show that parameterization of the computer model by combining direct laboratory measurements and thermodynamic data provides an integrated approach to predicting glass behavior over geologic-time scales.« less

A new scheme for velocity analysis and imaging of diffractions

NASA Astrophysics Data System (ADS)

Lin, Peng; Peng, Suping; Zhao, Jingtao; Cui, Xiaoqin; Du, Wenfeng

2018-06-01

Seismic diffractions are the responses of small-scale inhomogeneities or discontinuous geological features, which play a vital role in the exploitation and development of oil and gas reservoirs. However, diffractions are generally ignored and considered as interference noise in conventional data processing. In this paper, a new scheme for velocity analysis and imaging of seismic diffractions is proposed. Two steps compose of this scheme in our application. First, the plane-wave destruction method is used to separate diffractions from specular reflections in the prestack domain. Second, in order to accurately estimate migration velocity of the diffractions, the time-domain dip-angle gathers are derived from a Kirchhoff-based angle prestack time migration using separated diffractions. Diffraction events appear flat in the dip-angle gathers when imaged above the diffraction point with selected accurate migration velocity for diffractions. The selected migration velocity helps to produce the desired prestack imaging of diffractions. Synthetic and field examples are applied to test the validity of the new scheme. The diffraction imaging results indicate that the proposed scheme for velocity analysis and imaging of diffractions can provide more detailed information about small-scale geologic features for seismic interpretation.

Geologic map of MTM -45252 and-45257 quadrangles, Reull Vallis region of Mars

USGS Publications Warehouse

Mest, Scott C.; Crown, David A.

2003-01-01

Mars Transverse Mercator (MTM) quadrangles -45252 and -45257 (latitude 42.5° S. to 47.5°S., longitude 250° W. to 260° W.) cover a portion of the highlands of Promethei Terra east of Hellas basin. The map area consists of heavily cratered ancient highland materials having moderate to high relief, isolated knobs and massifs of rugged mountainous material, and extensive tracts of smooth and channeled plains. Part of the ~1,500-km-long Reull Vallis outflow system is within the map area. The area also contains surficial deposits, such as the prominent large debris aprons that commonly surround highland massifs. Regional slopes are to the west, toward the Hellas basin, as indicated by topographic maps of Mars. Approximately 60 percent of the surface of Mars is covered by rugged, heavily cratered terrains believed to represent the effects of heavy bombardment in the inner solar system about 4.0 billion years ago. Much of this terrain, including that within the map area, records a long history of modification by tectonism, fluvial processes, mass wasting, and eolian activity. The presence of fluvial features to the east of Hellas basin, including Reull Vallis and other smaller channels, has significant implications for past environmental conditions. The degraded terrains surrounding Hellas basin provide constraints on the role and timing of volatile-driven activity in the evolution of the highlands. Current photogeologic mapping at 1:500,000 scale (see also Mest and Crown, 2002) from analysis of Viking Orbiter images complements previous geomorphic studies of Reull Vallis and other highland outflow systems, drainage networks, and highland debris aprons, as well as regional geologic mapping studies and geologic mapping of Hellas basin as a whole at 1:5,000,000 scale. Viking Orbiter image coverage of the map area generally ranges from 160 to 220 m/pixel; the central part of the map area is covered by higher resolution images of about 47 m/pixel. Crater size-frequency distributions have been compiled to constrain the relative ages of geologic units and determine the timing and duration of inferred geologic processes.

Time scales of critical events around the Cretaceous-Paleogene boundary.

PubMed

Renne, Paul R; Deino, Alan L; Hilgen, Frederik J; Kuiper, Klaudia F; Mark, Darren F; Mitchell, William S; Morgan, Leah E; Mundil, Roland; Smit, Jan

2013-02-08

Mass extinctions manifest in Earth's geologic record were turning points in biotic evolution. We present (40)Ar/(39)Ar data that establish synchrony between the Cretaceous-Paleogene boundary and associated mass extinctions with the Chicxulub bolide impact to within 32,000 years. Perturbation of the atmospheric carbon cycle at the boundary likely lasted less than 5000 years, exhibiting a recovery time scale two to three orders of magnitude shorter than that of the major ocean basins. Low-diversity mammalian fauna in the western Williston Basin persisted for as little as 20,000 years after the impact. The Chicxulub impact likely triggered a state shift of ecosystems already under near-critical stress.

Geologic uncertainty in a regulatory environment: An example from the potential Yucca Mountain nuclear waste repository site

NASA Astrophysics Data System (ADS)

Rautman, C. A.; Treadway, A. H.

1991-11-01

Regulatory geologists are concerned with predicting the performance of sites proposed for waste disposal or for remediation of existing pollution problems. Geologic modeling of these sites requires large-scale expansion of knowledge obtained from very limited sampling. This expansion induces considerable uncertainty into the geologic models of rock properties that are required for modeling the predicted performance of the site. One method for assessing this uncertainty is through nonparametric geostatistical simulation. Simulation can produce a series of equiprobable models of a rock property of interest. Each model honors measured values at sampled locations, and each can be constructed to emulate both the univariate histogram and the spatial covariance structure of the measured data. Computing a performance model for a number of geologic simulations allows evaluation of the effects of geologic uncertainty. A site may be judged acceptable if the number of failures to meet a particular performance criterion produced by these computations is sufficiently low. A site that produces too many failures may be either unacceptable or simply inadequately described. The simulation approach to addressing geologic uncertainty is being applied to the potential high-level nuclear waste repository site at Yucca Mountain, Nevada, U.S.A. Preliminary geologic models of unsaturated permeability have been created that reproduce observed statistical properties reasonably well. A spread of unsaturated groundwater travel times has been computed that reflects the variability of those geologic models. Regions within the simulated models exhibiting the greatest variability among multiple runs are candidates for obtaining the greatest reduction in uncertainty through additional site characterization.

Geologic controls on regional and local erosion rates of three northern Gulf of Mexico barrier-island systems

USGS Publications Warehouse

Twitchell, David C.; Flocks, James G.; Pendleton, Elizabeth; Baldwin, Wayne E.

2013-01-01

The stratigraphy of sections of three barrier island systems in the northeastern Gulf of Mexico (Apalachicola, Mississippi, and Chandeleur) have been mapped using geophysical and coring techniques to assess the influence of geologic variations in barrier lithosomes and adjoining inner shelf deposits on long-term rates of shoreline change at regional and local scales. Regional scale was addressed by comparing average geologic characteristics of the three areas with mean shoreline-change rates for each area. Regionally, differences in sand volume contained within the part of the barrier lithosome above sea level, sand volume on the inner shelf, and to a lesser extent, sediment grain size correlate with shoreline change rates. Larger sand volumes and coarser grain sizes are found where erosion rates are lower. Local scale was addressed by comparing alongshore variations in barrier island and inner shelf geology with alongshore variations in shoreline change. Locally, long-term shoreline change rates are highest directly shoreward of paleovalleys exposed on the inner shelf. While geology is not the sole explanation for observed differences in shoreline change along these three coastal regions, it is a significant contributor to change variability.

Surficial Geologic Map of the Ashby-Lowell-Sterling-Billerica 11-Quadrangle Area in Northeast-Central Massachusetts

USGS Publications Warehouse

Stone, Byron D.; Stone, Janet R.

2007-01-01

The surficial geologic map shows the distribution of nonlithified earth materials at land surface in an area of eleven 7.5-minute quadrangles (total 505 mi2) in northeast-central Massachusetts. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics (such as grain size and sedimentary structures), constructional geomorphic features, stratigraphic relationships, and age. Surficial earth materials significantly affect human use of the land, and an accurate description of their distribution is particularly important for water resources, construction aggregate resources, earth-surface hazards assessments, and land-use decisions. This compilation of surficial geologic materials is an interim product that defines the areas of exposed bedrock, and the boundaries between glacial till, glacial stratified deposits, and overlying postglacial deposits. This work is part of a comprehensive study to produce a statewide digital map of the surficial geology at a 1:24,000-scale level of accuracy. This report includes explanatory text (PDF), a regional map at 1:50,000 scale (PDF), quadrangle maps at 1:24,000 scale (PDF files), GIS data layers (ArcGIS shapefiles), metadata for the GIS layers, scanned topographic base maps (TIF), and a readme.txt file.

Surficial Geologic Map of the Salem Depot-Newburyport East-Wilmington-Rockport 16-Quadrangle Area in Northeast Massachusetts

USGS Publications Warehouse

Stone, Byron D.; Stone, Janet Radway; DiGiacomo-Cohen, Mary L.

2006-01-01

The surficial geologic map shows the distribution of nonlithified earth materials at land surface in an area of 16 7.5-minute quadrangles (total 658 mi2) in northeast Massachusetts. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics (grain size, sedimentary structures, mineral and rock-particle composition), constructional geomorphic features, stratigraphic relationships, and age. Surficial earth materials significantly affect human use of the land, and an accurate description of their distribution is particularly important for water resources, construction aggregate resources, earth-surface hazards assessments, and land-use decisions. This compilation of surficial geologic materials is an interim product that defines the areas of exposed bedrock, and the boundaries between glacial till, glacial stratified deposits, and overlying postglacial deposits. This work is part of a comprehensive study to produce a statewide digital map of the surficial geology at a 1:24,000-scale level of accuracy. This report includes explanatory text (PDF), a regional map at 1:50,000 scale (PDF), quadrangle maps at 1:24,000 scale (PDF files), GIS data layers (ArcGIS shapefiles), metadata for the GIS layers, scanned topographic base maps (TIF), and a readme.txt file.

Horizontal sliding of kilometre-scale hot spring area during the 2016 Kumamoto earthquake

PubMed Central

Tsuji, Takeshi; Ishibashi, Jun’ichiro; Ishitsuka, Kazuya; Kamata, Ryuichi

2017-01-01

We report horizontal sliding of the kilometre-scale geologic block under the Aso hot springs (Uchinomaki area) caused by vibrations from the 2016 Kumamoto earthquake (Mw 7.0). Direct borehole observations demonstrate the sliding along the horizontal geological formation at ~50 m depth, which is where the shallowest hydrothermal reservoir developed. Owing to >1 m northwest movement of the geologic block, as shown by differential interferometric synthetic aperture radar (DInSAR), extensional open fissures were generated at the southeastern edge of the horizontal sliding block, and compressional deformation and spontaneous fluid emission from wells were observed at the northwestern edge of the block. The temporal and spatial variation of the hot spring supply during the earthquake can be explained by the horizontal sliding and borehole failures. Because there was no strain accumulation around the hot spring area prior to the earthquake and gravitational instability could be ignored, the horizontal sliding along the low-frictional formation was likely caused by seismic forces from the remote earthquake. The insights derived from our field-scale observations may assist further research into geologic block sliding in horizontal geological formations. PMID:28218298

Application of Research on the Metallogenic Background in the Assessment of Mineral Resources Potentiality

NASA Astrophysics Data System (ADS)

Jia, D.; Feng, Y.; Liu, J.; Yao, X.; Zhang, Z.; Ye, T.

2017-12-01

1. Working BackgroundCurrent Status of Geological Prospecting: Detecting boundaries and bottoms, making ore search nearby; Seeing the stars, not seeing the Moon; Deep prospecting, undesirable results. The reasons of these problems are the regional metallogenic backgroud unclear and the metallogenic backgroud of the exploration regions unknown. Accordingly, Development and Research Center, CGS organized a geological setting research, in detail investigate metallogenic geological features and acquire mineralization information. 2. Technical SchemeCore research content is prediction elements of Metallogenic Structure. Adopt unified technical requirements from top to bottom, and technical route from bottom to top; Divide elements of mineral forecast and characteristics of geological structure into five elements for research and expression; Make full use of geophysical, geochemical and remote sensing inferences for the interpretation of macro information. After eight years the great project was completed. 3. Main AchievementsInnovation of basic maps compilation content of geological background, reinforce of geological structure data base of potentiality valuation. Preparation of geotectonic facies maps in different scales and professions, providing brand-new geologic background for potentiality assessment, promoting Chinese geotectonic research to the new height. Preparation of 3,375 geological structure thematic base maps of detecting working area in 6 kinds of prediction methods, providing base working maps, rock assemblage, structure of the protolith of geologic body / mineralization / ore controlling for mineral prediction of 25 ores. Enrichment and development of geotectonic facies analysis method, establishment of metallogenic background research thoughts and approach system for assessment of national mineral resources potentiality for the first time. 4. Application EffectOrientation——More and better results with less effort. Positioning——Have a definite object in view. Heart calm down——Confidence.

Digital geologic map of McAlester-Texarkana quadrangles, southeastern Oklahoma

USGS Publications Warehouse

Cederstrand, J.R.

1997-01-01

This data set consists of digital data and accompanying documentation of the surficial geology of the 1:250,000-scale McAlester and Texarkana quadrangles, Oklahoma. The original data are from the Geologic Map, sheet 1 of 4, included in Oklahoma Geological Survey publication, Reconnaissance of the water resources of the McAlester and Texarkana quadrangles, southeastern Oklahoma, Hydrologic Atlas 9, Marcher and Bergman, 1983. The geology was compiled by M.V. Marcher and D.L. Bergman, 1971, and revised by R.O. Fay, 1978.

Geologic Storage at the Basin Scale: Region-Based Basin Modeling, Powder River Basin (PRB), NE Wyoming and SE Montana

NASA Astrophysics Data System (ADS)

Melick, J. J.; Gardner, M. H.

2008-12-01

Carbon capture and storage from the over 2000 power plants is estimated at 3-5 GT/yr, which requires large- scale geologic storage of greenhouse gasses in sedimentary basins. Unfortunately, determination of basin scale storage capacity is currently based on oversimplified geologic models that are difficult to validate. Simplification involves reducing the number of geologic parameters incorporated into the model, modeling with large grid cells, and treatment of subsurface reservoirs as homogeneous media. The latter problem reflects the focus of current models on fluid and/or fluid-rock interactions rather than fluid movement and migration pathways. For example, homogeneous models over emphasize fluid behavior, like the buoyancy of super-critical CO2, and hence overestimate leakage rates. Fluid mixing and fluid-rock interactions cannot be assessed with models that only investigate these reactions at a human time scale. Preliminary and conservative estimates of the total pore volume for the PRB suggest 200 GT of supercritical CO2 can be stored in this typical onshore sedimentary basin. The connected pore volume (CPV) however is not included in this estimate. Geological characterization of the CPV relates subsurface storage units to the most prolific reservoir classes (RCs). The CPV, number of well penetrations, supercritical storage area, and potential leakage pathways characterize each RC. Within each RC, a hierarchy of stratigraphic cycles is populated with stationary sedimentation regions that control rock property distributions by correlating environment of deposition (EOD) to CPV. The degree to which CPV varies between RCs depends on the geology and attendant heterogeneity retained in the fluid flow model. Region-based modeling of the PRB incorporates 28000 wells correlated across a 70,000 Km2 area, 2 km thick on average. Within this basin, five of the most productive RCs were identified from production history and placed in a fourfold stratigraphic framework (second- through fourth-order cycles). Within the small- scale 4th-order sequences (30-150-m thick, 16 total), sedimentation regions, each corresponding to an EOD, are defined by thickness, lithology and core-calibrated well-log patterns. This talk illustrates the workflow by focusing on one of the 16 layers in the basin-scale model. Isopach maps from this sample layer conform to depositional patterns confirmed through definition of five core-calibrated, well-log defined sedimentation regions. Lithology distributions also conform to thickness trends in nearshore deltas, but not in offshore regions, where sand-rich and sheet-like, but thin-bedded sandstones are flanked by mud-rich intervals of equivalent thickness. These maps represent sedimentation patterns confined by basal erosional sequence boundary and basin-wide bentonite, yet containing up to seven high-frequency sequence boundaries. To illustrate over simplification problems in this same layer, a 14000 km2 sample area is 600 km3 and using standard averaging methods, which are considered to be geologic in origin, the CPV is 16 km3. However, averaging increases connectivity with high CPV more uniformly distributed; significantly, the key mud belt region separating nearshore from offshore sandstones is not represented. Region-based modeling of this layer yields 13 km3 (110 Bbl). Furthermore, significant vertical leakage may exist from the 20000 well penetrations and faults and fractures along the western basin margin. This example illustrates the importance of accurately characterizing heterogeneity and distributing CPV using sedimentation regions.

Pore-scale observation and 3D simulation of wettability effects on supercritical CO2 - brine immiscible displacement in drainage

NASA Astrophysics Data System (ADS)

Hu, R.; Wan, J.; Chen, Y.

2016-12-01

Wettability is a factor controlling the fluid-fluid displacement pattern in porous media and significantly affects the flow and transport of supercritical (sc) CO2 in geologic carbon sequestration. Using a high-pressure micromodel-microscopy system, we performed drainage experiments of scCO2 invasion into brine-saturated water-wet and intermediate-wet micromodels; we visualized the scCO2 invasion morphology at pore-scale under reservoir conditions. We also performed pore-scale numerical simulations of the Navier-Stokes equations to obtain 3D details of fluid-fluid displacement processes. Simulation results are qualitatively consistent with the experiments, showing wider scCO2 fingering, higher percentage of scCO2 and more compact displacement pattern in intermediate-wet micromodel. Through quantitative analysis based on pore-scale simulation, we found that the reduced wettability reduces the displacement front velocity, promotes the pore-filling events in the longitudinal direction, delays the breakthrough time of invading fluid, and then increases the displacement efficiency. Simulated results also show that the fluid-fluid interface area follows a unified power-law relation with scCO2 saturation, and show smaller interface area in intermediate-wet case which suppresses the mass transfer between the phases. These pore-scale results provide insights for the wettability effects on CO2 - brine immiscible displacement in geologic carbon sequestration.

Geologic map of the Grand Canyon 30' x 60' quadrangle, Coconino and Mohave Counties, northwestern Arizona

USGS Publications Warehouse

Billingsley, G.H.

2000-01-01

This digital map database, compiled from previously published and unpublished data as well as new mapping by the author, represents the general distribution of bedrock and surficial deposits in the map area. Together with the accompanying pamphlet, it provides current information on the geologic structure and stratigraphy of the Grand Canyon area. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:100,000 or smaller.

Multidisciplinary geoscientific experiments in central Europe

NASA Technical Reports Server (NTRS)

Bannert, D. (Principal Investigator)

1974-01-01

The author has identified the following significant results. Studies were carried out in the fields of geology-pedology, coastal dynamics, geodesy-cartography, geography, and data processing. In geology-pedology, a comparison of ERTS image studies with extensive ground data led to a better understanding of the relationship between vegetation, soil, bedrock, and other geologic features. Findings in linear tectonics gave better insight in orogeny and ore deposit development for prospecting. Coastal studies proved the value of ERTS images for the updating of nautical charts, as well as small scale topographic maps. A plotter for large scale high speed image generation from CCT was developed.

Approximate Seismic Diffusive Models of Near-Receiver Geology: Applications from Lab Scale to Field

NASA Astrophysics Data System (ADS)

King, Thomas; Benson, Philip; De Siena, Luca; Vinciguerra, Sergio

2017-04-01

This paper presents a novel and simple method of seismic envelope analysis that can be applied at multiple scales, e.g. field, m to km scale and laboratory, mm to cm scale, and utilises the diffusive approximation of the seismic wavefield (Wegler, 2003). Coefficient values for diffusion and attenuation are obtained from seismic coda energies and are used to describe the rate at which seismic energy is scattered and attenuated into the local medium around a receiver. Values are acquired by performing a linear least squares inversion of coda energies calculated in successive time windows along a seismic trace. Acoustic emission data were taken from piezoelectric transducers (PZT) with typical resonance frequency of 1-5MHz glued around rock samples during deformation laboratory experiments carried out using a servo-controlled triaxial testing machine, where a shear/damage zone is generated under compression after the nucleation, growth and coalescence of microcracks. Passive field data were collected from conventional geophones during the 2004-2008 eruption of Mount St. Helens volcano (MSH), USA where a sudden reawakening of the volcanic activity and a new dome growth has occurred. The laboratory study shows a strong correlation between variations of the coefficients over time and the increase of differential stress as the experiment progresses. The field study links structural variations present in the near-surface geology, including those seen in previous geophysical studies of the area, to these same coefficients. Both studies show a correlation between frequency and structural feature size, i.e. landslide slip-planes and microcracks, with higher frequencies being much more sensitive to smaller scale features and vice-versa.

Geologic Mapping of the Beta-Atla-Themis (BAT) Region of Venus: A Progress Report

NASA Technical Reports Server (NTRS)

Bleamaster, Leslie F., III

2009-01-01

The BAT province is of particular interest with respect to evaluating Venus geologic, tectonic, and volcanic history and provides tests of global paradigms regarding her thermal evolution. The BAT is "ringed" by volcano-tectonic troughs (Parga, Hecate, and Devana Chasmata), has an anomalously high-density of volcanic features with concentrations 2-4 times the global average [1], and is spatially coincident with "young terrain" as illustrated by Average Surface Model Ages [2, 3]. The BAT province is key to understanding Venus current volcanic and tectonic modes, which may provide insight for evaluating Venus historical record. Several quadrangles, two 1:5,000,000 scale - Isabella (V-50) Quadrangle and Devana Chasma (V-29) Quadrangle and two 1:10,000,000 scale - Helen Planitia (I-2477) and Guinevere Planitia (I-2457), are in various stages of production (Figure 1). This abstract will report on their levels of completion as well as highlight some current results and outstanding issues.

Land-use changes and the physical habitat of streams - a review with emphasis on studies within the U.S. Geological Survey Federal-State Cooperative Program

USGS Publications Warehouse

Jacobson, Robert B.; Femmer, Suzanne R.; McKenney, Rose A.

2001-01-01

Understanding the links between land-use changes and physical stream habitat responses is of increasing importance to guide resource management and stream restoration strategies. Transmission of runoff and sediment to streams can involve complex responses of drainage basins, including time lags, thresholds, and cumulative effects. Land-use induced runoff and sediment yield often combine with channel-scale disturbances that decrease flow resistance and erosion resistance, or increase stream energy. The net effects of these interactions on physical stream habitat—depth, velocity, substrate, cover, and temperature—are a challenge to predict. Improved diagnosis and predictive understanding of future change usually require multifaceted, multi-scale, and multidisciplinary studies based on a firm understanding of the history and processes operating in a drainage basin. The U.S. Geological Survey Federal-State Cooperative Program has been instrumental in fostering studies of the links between land use and stream habitat nationwide.

Database for the geologic map of upper Eocene to Holocene volcanic and related rocks in the Cascade Range, Washington

USGS Publications Warehouse

Barron, Andrew D.; Ramsey, David W.; Smith, James G.

2014-01-01

This digital database contains information used to produce the geologic map published as Sheet 1 in U.S. Geological Survey Miscellaneous Investigations Series Map I-2005. (Sheet 2 of Map I-2005 shows sources of geologic data used in the compilation and is available separately). Sheet 1 of Map I-2005 shows the distribution and relations of volcanic and related rock units in the Cascade Range of Washington at a scale of 1:500,000. This digital release is produced from stable materials originally compiled at 1:250,000 scale that were used to publish Sheet 1. The database therefore contains more detailed geologic information than is portrayed on Sheet 1. This is most noticeable in the database as expanded polygons of surficial units and the presence of additional strands of concealed faults. No stable compilation materials exist for Sheet 1 at 1:500,000 scale. The main component of this digital release is a spatial database prepared using geographic information systems (GIS) applications. This release also contains links to files to view or print the map sheet, main report text, and accompanying mapping reference sheet from Map I-2005. For more information on volcanoes in the Cascade Range in Washington, Oregon, or California, please refer to the U.S. Geological Survey Volcano Hazards Program website.

Geology of Unga Island and the northwestern part of Popof Island: Chapter 2 in A geological and geophysical study of the gold-silver vein system of Unga Island, Southwestern Alaska

USGS Publications Warehouse

Riehle, James R.; Wilson, Frederic H.; Shew, Nora B.; White, Willis H.

1999-01-01

The first geologic map of Unga Island was published by Atwood (1911; scale 1:250,000), who correctly inferred the middle Tertiary age of the volcanic rocks and made the important distinction between the lava flows and the intrusive domes. Although Burk's (1964) reconnaissance map of the Alaska Peninsula (scale 1:250,000) has been modified in some respects, it does correct Atwood's map by replacing the Kenai Formation on northwestern Unga Island with the Unga Conglomerate and by recognizing the older Stepovak Formation elsewhere on Unga and Popof Islands.U.S. Geological Survey (USGS) field studies that were focused on the mineral-resource potential of the Alaska Peninsula began in the late 1970's. These studies led to a geologic map of the Port Moller quadrangle--including Unga Island--at 1:250,000 scale (Wilson and others, 1995), as well as summaries of mineral occurrences and geochronological studies (Wilson and others, 1988, 1994) and a formal revision of the stratigraphic units of the Alaska Peninsula (Detterman and others, 1996). As follow-up to the regional studies, a detailed study of the vein systems on Unga Island was undertaken as a collaborative effort between USGS and private industry (White and Queen, 1989). The fieldwork leading to the present report and geologic map was started in 1978 (Riehle and others, 1982) and was completed as part of the vein study. The objective was a better understanding of the geologic setting of the vein systems: the geologic history of the host rocks, the structural controls on the veins, and the types of processes that likely caused the mineralization.

Universal Linear Scaling of Permeability and Time for Heterogeneous Fracture Dissolution

NASA Astrophysics Data System (ADS)

Wang, L.; Cardenas, M. B.

2017-12-01

Fractures are dynamically changing over geological time scale due to mechanical deformation and chemical reactions. However, the latter mechanism remains poorly understood with respect to the expanding fracture, which leads to a positively coupled flow and reactive transport processes, i.e., as a fracture expands, so does its permeability (k) and thus flow and reactive transport processes. To unravel this coupling, we consider a self-enhancing process that leads to fracture expansion caused by acidic fluid, i.e., CO2-saturated brine dissolving calcite fracture. We rigorously derive a theory, for the first time, showing that fracture permeability increases linearly with time [Wang and Cardenas, 2017]. To validate this theory, we resort to the direct simulation that solves the Navier-Stokes and Advection-Diffusion equations with a moving mesh according to the dynamic dissolution process in two-dimensional (2D) fractures. We find that k slowly increases first until the dissolution front breakthrough the outbound when we observe a rapid k increase, i.e., the linear time-dependence of k occurs. The theory agrees well with numerical observations across a broad range of Peclet and Damkohler numbers through homogeneous and heterogeneous 2D fractures. Moreover, the theory of linear scaling relationship between k and time matches well with experimental observations of three-dimensional (3D) fractures' dissolution. To further attest to our theory's universality for 3D heterogeneous fractures across a broad range of roughness and correlation length of aperture field, we develop a depth-averaged model that simulates the process-based reactive transport. The simulation results show that, regardless of a wide variety of dissolution patterns such as the presence of dissolution fingers and preferential dissolution paths, the linear scaling relationship between k and time holds. Our theory sheds light on predicting permeability evolution in many geological settings when the self-enhancing process is relevant. References: Wang, L., and M. B. Cardenas (2017), Linear permeability evolution of expanding conduits due to feedback between flow and fast phase change, Geophys. Res. Lett., 44(9), 4116-4123, doi: 10.1002/2017gl073161.

The Mediterranean Plio-Pleistocene: A reference frame for astronomically paced low and high latitude climate changes (Jean Baptiste Lamarck Medal Lecture)

NASA Astrophysics Data System (ADS)

Lourens, Lucas

2016-04-01

The astronomical theory of climate has revolutionized our understanding of past climate change and the development of highly accurate geologic time scales for the entire Cenozoic. Most of this understanding has started with the construction of high-resolution stable oxygen isotope (18O) records from planktonic and benthic foraminifera of open ocean deep marine sediments explored by the international drilling operations of DSDP, ODP and IODP. These efforts culminated into global ocean isotopic stacked records, which give a clear picture of the evolution of the climate state through time. Fundamental for these reconstructions are the assumptions made between the astronomical forcing and the tuned time series and the accuracy of the astronomical solution. In the past decades, an astronomically calibrated time scale for the Pliocene and Pleistocene of the Mediterranean has been developed, which has become the reference for the standard Geologic Time Scale. Characteristic of the studied marine sediments are the cyclic lithological alternations, reflecting the interference between obliquity and precession-paced low latitude climate variability. These interference patterns allowed to evaluate the accuracy of astronomical solutions and to constrain the dynamical ellipticity of the Earth and tidal dissipation by the Sun and the Moon, which in turn provided the backbone for the widely applied LR04 open ocean benthic isotope stack of the past 5 Myr. So far, the assumed time lags between orbital forcing and the global climate response as reflected in LR04 have not been tested, while these assumptions hark back to SPECMAP, using simple ice sheet models and a limited number of radiometric dates. In addition, LR04 adopted a shorter response time for the smaller ice caps during the Pliocene. Here I present the first benthic 18O record of the Mediterranean reference scale, which strikingly mirrors the LR04. I will use this record to discuss the assumed phase relations and its potential to constrain global sea level changes and their cause over the past 5.3 million years.

A Model for the Decrease in Amplitude of Carbon Isotope Excursions Throughout the Phanerozoic

NASA Astrophysics Data System (ADS)

Bachan, A.; Lau, K. V.; Saltzman, M.; Thomas, E.; Kump, L. R.; Payne, J.

2016-12-01

The geological cycling of carbon ties the ocean-­atmosphere carbon pool to Earth's biosphere and sedimentary reservoirs. Perturbations to this coupled system are recorded in the carbon-isotopic (δ13C) composition of marine carbonates. Large amplitude δ13C variations with durations of 0.5 - 10 m.y. are typically treated as individual events and interpreted accordingly. However, a recent compilation of Phanerozoic data reveals a decline in the variance of the δ13C record over time, suggesting a common underlying control. Here we propose that the redox structure of the continental shelves was a key determinant of the sensitivity of the geologic carbon cycle: when oxygen minimum zones (OMZs) were large, shallow, and prone to expansion, recurrent physical forcings (such as sea level and tectonics) would have had the capacity to drive large changes in the areal extent of OMZs, resulting in a strong leverage on δ13C values. Using a simple model of the geologic carbon cycle, we demonstrate that interactions between the carbon and phosphate cycles can result in amplification of recurrent forcings with periods in the 0.5 - 10 m.y. range. Thus, rather than requiring that physical forcings have their largest amplitude of variation on those time scales, enhanced sensitivity of the carbon cycle can account for the characteristic duration of δ13C excursions. Biologically mediated aspects of geologic carbon cycling, including the depth of bioturbation and evolution of pelagic calcifiers, likely drove a decline in the depth and extent of ocean anoxia over the Phanerozoic resulting in the stabilization of the geologic carbon cycle.

The 1:3M geologic map of Mercury: progress and updates

NASA Astrophysics Data System (ADS)

Galluzzi, Valentina; Guzzetta, Laura; Mancinelli, Paolo; Giacomini, Lorenza; Malliband, Christopher C.; Mosca, Alessandro; Wright, Jack; Ferranti, Luigi; Massironi, Matteo; Pauselli, Cristina; Rothery, David A.; Palumbo, Pasquale

2017-04-01

After the end of Mariner 10 mission a 1:5M geologic map of seven of the fifteen quadrangles of Mercury [Spudis and Guest, 1988] was produced. The NASA MESSENGER mission filled the gap by imaging 100% of the planet with a global average resolution of 200 m/pixel and this led to the production of a global 1:15M geologic map of the planet [Prockter et al., 2016]. Despite the quality gap between Mariner 10 and MESSENGER images, no global geological mapping project with a scale larger than 1:5M has been proposed so far. Here we present the status of an ongoing project for the geologic mapping of Mercury at an average output scale of 1:3M based on the available MESSENGER data. This project will lead to a fuller grasp of the planet's stratigraphy and surface history. Completing such a product for Mercury is an important goal in preparation for the forthcoming ESA/JAXA BepiColombo mission to aid selection of scientific targets and to provide context for interpretation of new data. At the time of this writing, H02 Victoria [Galluzzi et al., 2016], H03 Shakespeare [Guzzetta et al., 2016] and H04 Raditladi [Mancinelli et al., 2016] have been completed and H05 Hokusai [Rothery et al., 2017], H06 Kuiper [Giacomini et al., 2017], H07 Beethoven and H10 Derain [Malliband et al., 2017] are being mapped. The produced geologic maps were merged using the ESRI ArcGIS software adjusting discontinuous contacts along the quadrangle boundaries. Contact discrepancies were reviewed and discussed among the mappers of adjoining quadrangles in order to match the geological interpretation and provide a unique consistent stratigraphy. At the current stage, more than 20% of Mercury has now a complete 1:3M map and more than 40% of the planet will be covered soon by the maps that are being prepared. This research was supported by the Italian Space Agency (ASI) within the SIMBIOSYS project (ASI-INAF agreement no. I/022/10/0). References Galluzzi V. et al. (2016). Geology of the Victoria Quadrangle (H02), Mercury. J. Maps, 12, 226-238. Giacomini L. et al. (2017). Geological mapping of the Kuiper quadrangle (H06) of Mercury. EGU General Assembly 2017, Abs. #14574. Guzzetta L. et al. (2016). Geologic map of the Shakespeare Quadrangle (H03) of Mercury. 88th Congress of the Italian Geological Society, 7-9 Sep 2016, Naples. Malliband C.C. et al. (2017). Preliminary results of 1:3million geological mapping of the Mercury quadrangle H-10 (Derain). XLVIII LPSC Abs., #1476. Mancinelli P. et al. (2016). Geology of the Raditladi Quadrangle, Mercury (H04). J. Maps, 12, 190-202. Prockter L. M. et al. (2016). The First Global Geological Map of Mercury. XLVII LPSC., Abs. #1245. Rothery D. A. et al. (2017). Geological mapping of the Hokusai (H05) quadrangle of Mercury. XLVIII LPSC, Abs. #1406. Spudis P. D. and Guest J. E. (1988). Stratigraphy and geologic history of Mercury. In: Vilas F., Chapman, C. R. and Matthews M. S. Eds., Mercury, 118-164. The University of Arizona Press, Tucson.

Observation to Theory in Deep Subsurface Microbiology Research: Can We Piece It Together?

NASA Astrophysics Data System (ADS)

Colwell, F. S.; Thurber, A. R.

2016-12-01

Three decades of observations of microbes in deep environments have led to startling discoveries of life in the subsurface. Now, a few theoretical frameworks exist that help to define Stygian life. Temperature, redox gradients, productivity (e.g., in the overlying ocean), and microbial power requirements are thought to determine the distribution of microbes in the subsurface. Still, we struggle to comprehend the spatial and temporal spectra of Earth processes that define how deep microbe communities survive. Stommel diagrams, originally used to guide oceanographic sampling, may be useful in depicting the subsurface where microbial communities are impacted by co-occurring spatial and temporal phenomena that range across exponential scales. Spatially, the geological settings that influence the activity and distribution of microbes range from individual molecules or minerals all the way up to the planetary-scale where geological formations, occupying up to 105 km3, dictate the bio- and functional geography of microbial communities. Temporally, life in the subsurface may respond in time units familiar to humans (e.g., seconds to days) or to events that unfold over hundred millennial time periods. While surface community dynamics are underpinned by solar and lunar cycles, these cycles only fractionally dictate survival underground where phenomena like tectonic activity, isostatic rebound, and radioactive decay are plausible drivers of microbial life. Geological or planetary processes that occur on thousand or million year cycles could be uniquely important to microbial viability in the subsurface. Such an approach aims at a holistic comprehension of the interaction of Earth system dynamics with microbial ecology.

The value of ERTS-1 imagery in resource inventorization on a national scale in South Africa

NASA Technical Reports Server (NTRS)

Malan, O. G.; Macvicar, C. N.; Edwards, D.; Temperley, B. N.; Claassen, L.

1974-01-01

It has been shown that ERTS imagery, particularly in the form of 1:500,000 scale false color photolithographic prints, can contribute very significantly towards facilitating and accelerating (dramatically, in some cases) resource surveys and geologic mapping. Fire mapping on a national scale becomes a feasability; numerous new geologic features, particularly lineaments, have been discovered, land use can be mapped efficiently on a regional scale and degraded areas identified. The first detailed tectonic and geomorphological maps of the Republic of South Africa will be published mainly owing to the availability of ERTS images.

Solar System Chaos and its climatic and biogeochemical consequences

NASA Astrophysics Data System (ADS)

Ikeda, M.; Tada, R.; Ozaki, K.; Olsen, P. E.

2017-12-01

Insolation changes caused by changes in Earth's orbital parameters are the main driver of climatic variations, whose pace has been used for astronomically-calibrated geologic time scales of high accuracy to understand Earth system dynamics. However, the astrophysical models beyond several tens of million years ago have large uncertainty due to chaotic behavior of the Solar System, and its impact on amplitude modulation of multi-Myr-scale orbital variations and consequent climate changes has become the subject of debate. Here we show the geologic constraints on the past chaotic behavior of orbital cycles from early Mesozoic monsoon-related records; the 30-Myr-long lake level records of the lacustrine sequence in Newark-Hartford basins (North America) and 70-Myr-long biogenic silica (BSi) burial flux record of pelagic deep-sea chert sequence in Inuyama area (Japan). BSi burial flux of chert could be considered as proportional to the dissolved Si (DSi) input from chemical weathering on timescales longer than the residence time of DSi ( 100 kyr), because chert could represent a major sink for oceanic dissolved silica (Ikeda et al., 2017).These geologic records show multi-Myr cycles with similar frequency modulations of eccentricity solution of astronomical model La2010d (Laskar et al., 2011) compared with other astronomical solutions, but not exactly same. Our geologic records provide convincing evidence for the past chaotic dynamical behaviour of the Solar System and new and challenging additional constraints for astrophysical models. In addition, we find that ˜10 Myr cycle detected in monsoon proxies and their amplitude modulation of ˜2 Myr cycle may be related to the amplitude modulation of ˜2 Myr eccentricity cycle through non-linear process(es) of Earth system dynamics, suggesting possible impact of the chaotic behavior of Solar planets on climate change. Further impact of multi-Myr orbital cycles on global biogeochemical cycles will be discussed.

Impacts of preferential flow on coastal groundwater-surface water interactions: The heterogeneous volcanic aquifer of Hawaii

NASA Astrophysics Data System (ADS)

Geng, X.; Kreyns, P.; Koneshloo, M.; Michael, H. A.

2017-12-01

Groundwater flow and salt transport processes are important for protection of coastal water resources and ecosystems. Geological heterogeneity has been recognized as a key factor affecting rates and patterns of groundwater flow and the evolution of subsurface salinity distributions in coastal aquifers. The hydrogeologic system of the volcanic Hawaiian Islands is characterized by lava flows that can form continuous, connected geologic structures in subsurface. Understanding the role of geological heterogeneity in aquifer salinization and water exchange between aquifers and the ocean is essential for effective assessment and management of water resources in the Hawaii islands. In this study, surface-based geostatistical techniques were adopted to generate geologically-realistic, statistically equivalent model realizations of the hydrogeologic system on the Big Island of Hawaii. The density-dependent groundwater flow and solute transport code SEAWAT was used to perform 3D simulations to investigate subsurface flow and salt transport through these random realizations. Flux across the aquifer-ocean interface, aquifer salinization, and groundwater flow pathways and associated transit times were quantified. Numerical simulations of groundwater pumping at various positions in the aquifers were also conducted, and associated impacts on saltwater intrusion rates were evaluated. Results indicate the impacts of continuous geologic features on large-scale groundwater processes in coastal aquifers.

Applying petrophysical models to radar travel time and electrical resistivity tomograms: Resolution-dependent limitations

USGS Publications Warehouse

Day-Lewis, F. D.; Singha, K.; Binley, A.M.

2005-01-01

Geophysical imaging has traditionally provided qualitative information about geologic structure; however, there is increasing interest in using petrophysical models to convert tomograms to quantitative estimates of hydrogeologic, mechanical, or geochemical parameters of interest (e.g., permeability, porosity, water content, and salinity). Unfortunately, petrophysical estimation based on tomograms is complicated by limited and variable image resolution, which depends on (1) measurement physics (e.g., electrical conduction or electromagnetic wave propagation), (2) parameterization and regularization, (3) measurement error, and (4) spatial variability. We present a framework to predict how core-scale relations between geophysical properties and hydrologic parameters are altered by the inversion, which produces smoothly varying pixel-scale estimates. We refer to this loss of information as "correlation loss." Our approach upscales the core-scale relation to the pixel scale using the model resolution matrix from the inversion, random field averaging, and spatial statistics of the geophysical property. Synthetic examples evaluate the utility of radar travel time tomography (RTT) and electrical-resistivity tomography (ERT) for estimating water content. This work provides (1) a framework to assess tomograms for geologic parameter estimation and (2) insights into the different patterns of correlation loss for ERT and RTT. Whereas ERT generally performs better near boreholes, RTT performs better in the interwell region. Application of petrophysical models to the tomograms in our examples would yield misleading estimates of water content. Although the examples presented illustrate the problem of correlation loss in the context of near-surface geophysical imaging, our results have clear implications for quantitative analysis of tomograms for diverse geoscience applications. Copyright 2005 by the American Geophysical Union.

Development of a New Analog Test System Capable of Modeling Tectonic Deformation Incorporating the Effects of Pore Fluid Pressure

NASA Astrophysics Data System (ADS)

Zhang, M.; Nakajima, H.; Takeda, M.; Aung, T. T.

2005-12-01

Understanding and predicting the tectonic deformation within geologic strata has been a very important research subject in many fields such as structural geology and petroleum geology. In recent years, such research has also become a fundamental necessity for the assessment of active fault migration, site selection for geological disposal of radioactive nuclear waste and exploration for methane hydrate. Although analog modeling techniques have played an important role in the elucidation of the tectonic deformation mechanisms, traditional approaches have typically used dry materials and ignored the effects of pore fluid pressure. In order for analog models to properly depict the tectonic deformation of the targeted, large-prototype system within a small laboratory-scale configuration, physical properties of the models, including geometry, force, and time, must be correctly scaled. Model materials representing brittle rock behavior require an internal friction identical to the prototype rock and virtually zero cohesion. Granular materials such as sand, glass beads, or steel beads of dry condition have been preferably used for this reason in addition to their availability and ease of handling. Modeling protocols for dry granular materials have been well established but such model tests cannot account for the pore fluid effects. Although the concept of effective stress has long been recognized and the role of pore-fluid pressure in tectonic deformation processes is evident, there have been few analog model studies that consider the effects of pore fluid movement. Some new applications require a thorough understanding of the coupled deformation and fluid flow processes within the strata. Taking the field of waste management as an example, deep geological disposal of radioactive waste has been thought to be an appropriate methodology for the safe isolation of the wastes from the human environment until the toxicity of the wastes decays to non-hazardous levels. For the deep geological disposal concept, besides containing the wastes with engineering methods such as the glassification of the radioactive wastes, the geological formation itself is expected to serve as a natural barrier that retards migration of radionuclides. To evaluate the long-term safety of deep geological disposal, a better understanding of the fate and transport of radionuclides in a geologically heterogeneous environment is necessary. To meet such requirements, a new analog test sandbox model system was developed. This model system allows the pore fluid flows to be controlled during the model tests and permits the study of flow and transport phenomena in the deformed heterogeneous model. One- or two-dimensional fluid flow is controlled using a side-wall piston. Deformation processes can be observed through a transparent front panel, and pore fluid movement can be also visualized using a color tracer. In this study, the scaling requirements for analog modeling, including pore water pressure, are discussed based on the theory of dimensional analysis, supplemented by data from a series of laboratory shear tests, and a detailed description of the model system. Preliminary experimental results are presented.

Basic Research Needs for Electrical Energy Storage. Report of the Basic Energy Sciences Workshop on Electrical Energy Storage, April 2-4, 2007

DOE R&D Accomplishments Database

Goodenough, J. B.; Abruna, H. D.; Buchanan, M. V.

2007-04-04

To identify research areas in geosciences, such as behavior of multiphase fluid-solid systems on a variety of scales, chemical migration processes in geologic media, characterization of geologic systems, and modeling and simulation of geologic systems, needed for improved energy systems.

Geologic map of the Cucamonga Peak 7.5' quadrangle, San Bernardino County, California

USGS Publications Warehouse

Morton, D.M.; Matti, J.C.; Digital preparation by Koukladas, Catherine; Cossette, P.M.

2001-01-01

a. This Readme; includes in Appendix I, data contained in fif_met.txt b. The same graphic as plotted in 2 above. (Test plots have not produced 1:24,000-scale map sheets. Adobe Acrobat pagesize setting influences map scale.) The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Miscellaneous Investigations Series (I-series) maps but has not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. Even though this is an author-prepared report, every attempt has been made to closely adhere to the stratigraphic nomenclature of the U. S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above). If roads in some areas, especially forest roads that parallel topographic contours, do not show well on plots of the geologic map, we recommend use of the USGS Cucamonga Peak 7.5’ topographic quadrangle in conjunction with the geologic map.

Geologic map of the Telegraph Peak 7.5' quadrangle, San Bernardino County, California

USGS Publications Warehouse

Morton, D.M.; Woodburne, M.O.; Foster, J.H.; Morton, Gregory; Cossette, P.M.

2001-01-01

a. This Readme; includes in Appendix I, data contained in fif_met.txt b. The same graphic as plotted in 2 above. Test plots have not produced 1:24,000-scale map sheets. Adobe Acrobat pagesize setting influences map scale. The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Miscellaneous Investigations Series (I-series) maps but has not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. Even though this is an author-prepared report, every attempt has been made to closely adhere to the stratigraphic nomenclature of the U. S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above). If roads in some areas, especially forest roads that parallel topographic contours, do not show well on plots of the geologic map, we recommend use of the USGS Telegraph Peak 7.5’ topographic quadrangle in conjunction with the geologic map.

Changes in Geologic Time Understanding in a Class for Preservice Teachers

ERIC Educational Resources Information Center

Teed, Rebecca; Slattery, William

2011-01-01

The paradigm of geologic time is built on complex concepts, and students master it in multiple steps. Concepts in Geology is an inquiry-based geology class for preservice teachers at Wright State University. The instructors used the Geoscience Concept Inventory (GCI) to determine if students' understanding of key ideas about geologic time and…

A Global Geologic Map of Europa

NASA Astrophysics Data System (ADS)

Janelle Leonard, Erin; Patthoff, Donald Alex; Senske, David A.; Collins, Geoffrey

2017-10-01

Understanding the global scale geology of Europa is paramount to gaining insight into the potential habitability of this icy world. To this end, work is ongoing to complete a global geological map at the scale of 1:15 million that incorporates data at all resolutions collected by the Voyager and Galileo missions. The results of this work will aid the Europa Clipper mission, now in formulation, by providing a framework for collaborative and synergistic science investigations.To understand global geologic and tectonic relations, a total of 10 geologic units have been defined. These include: Low Albedo Ridge Material (lam)—low albedo material that irregularly surrounds large (>20 km) ridge structures; Ridged plains (pr)—distributed over all latitudes and characterized by subparallel to cross-cutting ridges and troughs visible at high resolution (<100 m/px); Band material (b)—linear to curvilinear zones with a distinct, abrupt albedo change from the surrounding region; Crater material (c), Continuous Crater Ejecta (ce) and Discontinuous Crater Ejecta (dce)—features associated with impact craters including the site of the impact, crater material, and the fall-out debris respectively; Low Albedo Chaos (chl), Mottled Albedo Chaos (chm) and High Albedo Chaos (chh)—disrupted terrain with a relatively uniform low albedo, patchy/variegated albedo, and uniform high albedo appearance respectively; Knobby Chaos (chk) - disrupted terrain with rough and blocky texture occurring in the high latitudes.In addition to the geologic units, our mapping also includes structural features—Ridges, Cycloids, Undifferentiated Linea, Crater Rims, Depression Margins, Dome Margins and Troughs. We also introduce a point feature (at the global scale), Microchaos, to denote small (<10 km) patches of discontinuous chaos material. The completed map will constrain the distribution of different Europa terrains and provide a general stratigraphic framework to assess the geologic history of Europa from the regional to the global scale.

The First USGS Global Geologic Map of Europa

NASA Astrophysics Data System (ADS)

Leonard, E. J.; Patthoff, D. A.; Senske, D.; Collins, G. C.

2017-12-01

Understanding the global scale geology of Europa is paramount to gaining insight into the potential habitability of this icy world. To this end, work is ongoing to complete a global geological map at the scale of 1:15 million that incorporates data at all resolutions collected by the Voyager and Galileo missions. The results of this work will aid the Europa Clipper mission, now in formulation, by providing a framework for collaborative and synergistic science investigations. To understand global geologic and tectonic relations, a total of 10 geologic units have been defined. These include: Low Albedo Ridge Material (lam)—low albedo material that irregularly surrounds large (>20 km) ridge structures; Ridged plains (pr)—distributed over all latitudes and characterized by subparallel to cross-cutting ridges and troughs visible at high resolution (<100 m/px); Band material (b)—linear to curvilinear zones with a distinct, abrupt albedo change from the surrounding region; Crater material (c), Continuous Crater Ejecta (ce) and Discontinuous Crater Ejecta (dce)—features associated with impact craters including the site of the impact, crater material, and the fall-out debris respectively; Low Albedo Chaos (chl), Mottled Albedo Chaos (chm) and High Albedo Chaos (chh)—disrupted terrain with a relatively uniform low albedo, patchy/variegated albedo, and uniform high albedo appearance respectively; Knobby Chaos (chk) - disrupted terrain with rough and blocky texture occurring in the high latitudes. In addition to the geologic units, our mapping also includes structural features—Ridges, Cycloids, Undifferentiated Linea, Crater Rims, Depression Margins, Dome Margins and Troughs. We also introduce a point feature (at the global scale), Microchaos, to denote small (<10 km) patches of discontinuous chaos material. The completed map will constrain the distribution of different Europa terrains and provide a general stratigraphic framework to assess the geologic history of Europa from the regional to the global scale. Here, we present the map submitted to the USGS for review.

Geologic Map of the Frederick 30' x 60' Quadrangle, Maryland, Virginia, and West Virginia

USGS Publications Warehouse

Southworth, Scott; Brezinski, David K.; Drake, Avery Ala; Burton, William C.; Orndorff, Randall C.; Froelich, Albert J.; Reddy, James E.; Denenny, Danielle; Daniels, David L.

2007-01-01

The Frederick 30? ? 60? quadrangle lies within the Potomac River watershed of the Chesapeake Bay drainage basin. The map area covers parts of Montgomery, Howard, Carroll, Frederick, and Washington Counties in Maryland; Loudoun, Clarke, and Fairfax Counties in Virginia; and Jefferson and Berkeley Counties in West Virginia. Many geologic features (such as faults and folds) are named for geographic features that may or may not be shown on the 1:100,000-scale base map. The geology of the Frederick 30? ? 60? quadrangle, Maryland, Virginia, and West Virginia, was first mapped on the 32 1:24,000-scale 7.5-minute quadrangle base maps between 1989 and 1994. The geologic data were compiled manually at 1:100,000 scale in 1997 and were digitized between 1998 and 1999. The geologic map and database may be used to support activities such as land-use planning, soil mapping, groundwater availability and quality studies, identifying aggregate resources, and conducting engineering and environmental studies. The map area covers distinct geologic provinces and sections of the central Appalachian region that are defined by unique bedrock and resulting landforms. From west to east, the provinces include the Great Valley section of the Valley and Ridge province, the Blue Ridge province, and the Piedmont province; in the extreme southeastern corner, a small part of the Coastal Plain province is present. The Piedmont province is divided into several sections; from west to east, hey are the Frederick Valley synclinorium, the Culpeper and Gettysburg basins, the Sugarloaf Mountain anticlinorium, the Westminster terrane, and the Potomac terrane. The geology of the Frederick quadrangle is discussed by geologic province and sections; the geologic units within each province are discussed from oldest to youngest. Where applicable, the discussion includes information on tectonic origins. For more information concerning the report, please contact the author.

Geologic map of the Wildcat Lake 7.5' quadrangle: Kitsap and Mason counties, Washington

USGS Publications Warehouse

Haeussler, Peter J.; Clark, Kenneth P.

2000-01-01

The Wildcat Lake quadrangle lies in the forearc of the Cascadia subduction zone, about 20-km east of the Cascadia accretionary complex exposed in the Olympic Mountains (Tabor and Cady, 1978),and about 100-km west of the axis of the Cascades volcanic arc. The quadrangle lies near the middle of the Puget Lowland, which typically has elevations less than 600 feet (183 m), but on Gold Mountain, in the center of the quadrangle, the elevation rises to 1761 feet (537 m). This anomalously high topography also provides a glimpse of the deeper crust beneath the Lowland. Exposed on Green and Gold Mountains are rocks related to the Coast Range basalt terrane. This terrane consists of Eocene submarine and subaerial tholeiitic basalt of the Crescent Formation, which probably accreted to the continental margin in Eocene time (Snavely and others, 1968). The Coast Range basalt terrane may have originated as an oceanic plateau or by oblique marginal rifting (Babcock and others, 1992), but its subsequent emplacement history is complex (Wells and others, 1984). In southern Oregon, onlapping strata constrain the suturing to have occured by 50 Ma; but on southern Vancouver Island where the terrane-bounding Leech River fault is exposed, Brandon and Vance (1992) concluded suturing to North America occurred in the broad interval between 42 and 24 Ma. After emplacement of the Coast Range basalt terrane, the Cascadia accretionary complex,exposed in the Olympic Mountains west of the quadrangle,developed by frontal accretion and underplating (e.g., Clowes and others, 1987). The Seattle basin, part of which lies to the north of Green Mountain, also began to develop in late Eocene time due to forced flexural subsidence along the Seattle fault zone (Johnson and others, 1994). Domal uplift of the accretionary complex beneath the Olympic Mountains occurred after approximately 18 million years ago (Brandon and others, 1998). Ice-sheet glaciation during Quaternary time reshaped the topography of the quadrangle, and approximately two-thirds of the map area is covered with Quaternary deposits related to the last glaciation. Geophysical studies and regional mapping indicate the Seattle fault lies north of Green Mountain. This fault produced a large earthquake about 1000 years ago and may pose a significant earthquake hazard (Bucknam and others, 1992; Atwater and Moore, 1992; Karlin and Abella,1992; Schuster and others, 1992; Jacoby and others, 1992). We found no evidence of Holocene faulting in the Wildcat Lake quadrangle. Geologic mapping within and marginal to the quadrangle began with Willis (1898), who described glacial deposits in Puget Sound. Weaver (1937) correlated volcanic rocks in the quadrangle to the Eocene Metchosin Volcanics on Vancouver Island. Sceva (1957), Garling and Moleenar (1965), and Deeter (1978) all focused on mapping and understanding the Quaternary stratigraphy of the Kitsap Peninsula, but they also examined bedrock in the quadrangle. Reeve (1979) was the first to examine the igneous rocks on Green and Gold Mountains in some detail, and Clark (1989) significantly improved Reeve's (1979) mapping. Clark's (1989) mapping was conducted soon after extensive logging on the mountains. A surficial geologic map of the Seattle 1:100,000-scale quadrangle, which includes the Wildcat Lake 1:24,000-scale quadrangle, was published by Yount and others (1993). Yount and Gower (1991) also published a bedrock geologic map of the Seattle quadrangle. Geologic mapping for this report was conducted by Haeussler in the spring and summer of 1998 and in the winter of 1999. We could not substantially improve upon the bedrock mapping of Clark (1989) and thus it is incorporated into this map. Well data in the southeastern corner of the map area also helped to constrain the surficial mapping (Geomatrix Consultants, 1997). In addition, 1995 vintage 1:12,000-scale aerial photographs were used in mapping Quaternary deposits. Geologic time scale is that of Berggeren and others (1995).

The Surface of Venus

NASA Astrophysics Data System (ADS)

Ivanov, M. A.; Head, J. W.

2018-03-01

This chapter reviews the conditions under which the basic landforms of Venus formed, interprets their nature, and analyzes their local, regional, and global age relationships. The strong greenhouse effect on Venus causes hyper-dry, almost stagnant near-surface environments. These conditions preclude water-driven, and suppress wind-related, geological processes; thus, the common Earth-like water-generated geological record of sedimentary materials does not currently form on Venus. Three geological processes are important on the planet: volcanism, tectonics, and impact cratering. The small number of impact craters on Venus ( 1,000) indicates that their contribution to resurfacing is minor. Volcanism and tectonics are the principal geological processes operating on Venus during its observable geologic history. Landforms of the volcanic and tectonic nature have specific morphologies, which indicate different modes of formation, and their relationships permit one to establish their relative ages. Analysis of these relationships at the global scale reveals that three distinct regimes of resurfacing comprise the observable geologic history of Venus: (1) the global tectonic regime, (2) the global volcanic regime, and (3) the network rifting-volcanism regime. During the earlier global tectonic regime, tectonic resurfacing dominated. Tectonic deformation at this time caused formation of strongly tectonized terrains such as tessera, and deformational belts. Exposures of these units comprise 20% of the surface of Venus. The apparent beginning of the global tectonic regime is related to the formation of tessera, which is among the oldest units on Venus. The age relationships among the tessera structures indicate that this terrain is the result of crustal shortening. During the global volcanic regime, volcanism overwhelmed tectonic activity and caused formation of vast volcanic plains that compose 60% of the surface of Venus. The plains show a clear stratigraphic sequence from older shield plains to younger regional plains. The distinctly different morphologies of the plains indicate different volcanic formation styles ranging from eruption through broadly distributed local sources of shield plains to the volcanic flooding of regional plains. The density of impact craters on units of the tectonic and volcanic regimes suggests that these regimes characterized about the first one-third of the visible geologic history of Venus. During this time, 80%–85% of the surface of the planet was renovated. The network rifting-volcanism regime characterized the last two-thirds of the visible geologic history of Venus. The major components of the regime include broadly synchronous lobate plains and rift zones. Although the network rifting-volcanism regime characterized 2/3 of the visible geologic history of Venus, only 15%–20% of the surface was resurfaced during this time. This means that the level of endogenous activity during this time has dropped by about an order of magnitude compared with the earlier regimes.

Geologic map of the Stephens City quadrangle, Clark, Frederick, and Warren Counties, Virginia

USGS Publications Warehouse

Weary, D.J.; Orndorff, R.C.; Aleman-Gonzalez, W.

2006-01-01

The Stephens City 1:24,000-scale quadrangle is one of several quadrangles in Frederick County, Virginia being mapped by geologists from the U.S. Geological Survey in Reston, VA with funding from the National Cooperative Geologic Mapping Program. This work is part of a project being lead by the U.S. Geological Survey Water Resources Discipline, Virginia District, to investigate the geologic framework and groundwater resources of Frederick County as well as other areas in the northern Shenandoah Valley of Virginia and West Virginia.

GeoSciML version 3: A GML application for geologic information

NASA Astrophysics Data System (ADS)

International Union of Geological Sciences., I. C.; Richard, S. M.

2011-12-01

After 2 years of testing and development, XML schema for GeoSciML version 3 are now ready for application deployment. GeoSciML draws from many geoscience data modelling efforts to establish a common suite of feature types to represent information associated with geologic maps (materials, structures, and geologic units) and observations including structure data, samples, and chemical analyses. After extensive testing and use case analysis, in December 2008 the CGI Interoperability Working Group (IWG) released GeoSciML 2.0 as an application schema for basic geological information. GeoSciML 2.0 is in use to deliver geologic data by the OneGeology Europe portal, the Geological Survey of Canada Groundwater Information Network (wet GIN), and the Auscope Mineral Resources portal. GeoSciML to version 3.0 is updated to OGC Geography Markup Language v3.2, re-engineered patterns for association of element values with controlled vocabulary concepts, incorporation of ISO19156 Observation and Measurement constructs for representing numeric and categorical values and for representing analytical data, incorporation of EarthResourceML to represent mineral occurrences and mines, incorporation of the GeoTime model to represent GSSP and stratigraphic time scale, and refactoring of the GeoSciML namespace to follow emerging ISO practices for decoupling of dependencies between standardized namespaces. These changes will make it easier for data providers to link to standard vocabulary and registry services. The depth and breadth of GeoSciML remains largely unchanged, covering the representation of geologic units, earth materials and geologic structures. ISO19156 elements and patterns are used to represent sampling features such as boreholes and rock samples, as well as geochemical and geochronologic measurements. Geologic structures include shear displacement structures (brittle faults and ductile shears), contacts, folds, foliations, lineations and structures with no preferred orientation (e.g. 'miarolitic cavities'). The Earth material package allows for the description of both individual components, such as minerals, and compound materials, such as rocks or unconsolidated materials. Provision is made for alteration, weathering, metamorphism, particle geometry, fabric, and petrophysical descriptions. Mapped features describe the shape of the geological features using standard GML geometries, such as polygons, lines, points or 3D volumes. Geological events provide the age, process and environment of formation of geological features. The Earth Resource section includes features to represent mineral occurrences and mines and associated human activities independently. This addition allows description of resources and reserves that can comply with national and internationally accepted reporting codes. GeoSciML v3 is under consideration as the data model for INSPIRE annex 2 geologic reporting in Europe.

Remote sensing of permafrost and geological hazards in Alaska

NASA Technical Reports Server (NTRS)

Ferrians, O. J., Jr. (Principal Investigator)

1973-01-01

The author has identified the following significant results. The study of the ERTS-1 imagery of Alaska indicates the following: that areas of different topographic expression affecting the distribution and character of permafrost can be distinguished clearly; that on the Arctic North Slope, regional differences in the distribution and character of permafrost-related oriented thaw lakes can be observed; that the distribution of certain types of geologic materials having a significant effect on the character of permafrost can be delineated on a regional scale; and that the resolution of the imagery is adequate to identify large scale geologic hazards such as landslides, glacier-dammed lakes, aufeis fields, etc. The information concerning the distribution and character of permafrost and geologic hazards to the gained in accomplishing the objectives of this project will be an invaluable aid in solving engineering-geologic and environmental problems related to route and site selection for structures such as roads, railroads, pipelines, and large installations; to distribution of natural construction materials; and to construction and maintenance.

Multi-criteria Resource Mapping and its Relevance in the Assessment of Habitat Changes

NASA Astrophysics Data System (ADS)

Van Lancker, V. R.; Kint, L.; van Heteren, S.

2016-02-01

Mineral and geological resources can be considered to be non-renewable on time scales relevant for decision makers. Once exhausted by humans, they are not replenished rapidly enough by nature, meaning that truly sustainable resource exploitation is not possible. Comprehensive knowledge on the distribution, composition and dynamics of geological resources and on the environmental impact of aggregate extraction is therefore critical. For the Belgian and southern Netherlands part of the North Sea, being representative of a typical sandbank system, a 4D resource decision-support system is being developed that links 3D geological models with environmental impact models. Aim is to quantify natural and man-made changes and to define from these sustainable exploitation thresholds. These are needed to ensure that recovery from perturbations is rapid and secure, and that the range of natural variation is maintained, a prerequisite stated in Europe's Marine Strategy Framework Directive, the environmental pillar of Europe's Maritime Policy. The geological subsurface is parameterised using a voxel modelling approach. Primarily, the voxels, or volume blocks of information, are constrained by the geology, based on coring and seismic data, but they are open to any resource-relevant information. The primary geological data entering the voxels are subdued to uncertainty modelling, a necessary step to produce data products with confidence limits. The presentation will focus on the novelty this approach brings for seabed and habitat mapping. In our model this is the upper voxel, providing the advantage of having a dynamical coupling to the geology and a suite of environmental parameters. In the context of assessing habitat changes, this coupling enables to account for spatial and temporal variability, seabed heterogeneity, as well as data uncertainty. The project is funded by Belgian Science Policy and is further valorised through EMODnet-Geology (DG MARE).

Surficial Geologic Map of the Clinton-Concord-Grafton-Medfield 12-Quadrangle Area in East Central Massachusetts

USGS Publications Warehouse

Stone, Janet R.; Stone, Byron D.

2006-01-01

The surficial geologic map shows the distribution of nonlithified earth materials at land surface in an area of twelve 7.5-minute quadrangles (total 660 square miles) in east-central Massachusetts. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics (grain size, sedimentary structures, mineral and rock-particle composition), constructional geomorphic features, stratigraphic relationships, and age. Surficial earth materials significantly affect human use of the land, and an accurate description of their distribution is particularly important for water resources, construction aggregate resources, earth-surface hazards assessments, and land-use decisions. This compilation of surficial geologic materials is an interim product that defines the areas of exposed bedrock, and the boundaries between glacial till, glacial stratified deposits, and overlying postglacial deposits. This work is part of a comprehensive study to produce a statewide digital map of the surficial geology at a 1:24,000-scale level of accuracy. This report includes explanatory text (PDF), a regional map at 1:50,000 scale (PDF), quadrangle maps at 1:24,000 scale (12 PDF files), GIS data layers (ArcGIS shapefiles), scanned topographic base maps (TIF), metadata for the GIS layers, and a readme.txt file.

Geologic map and map database of the Palo Alto 30' x 60' quadrangle, California

USGS Publications Warehouse

Brabb, E.E.; Jones, D.L.; Graymer, R.W.

2000-01-01

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (pamf.ps, pamf.pdf, pamf.txt), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:62,500 or smaller.

Geologic map and map database of western Sonoma, northernmost Marin, and southernmost Mendocino counties, California

USGS Publications Warehouse

Blake, M.C.; Graymer, R.W.; Stamski, R.E.

2002-01-01

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (wsomf.ps, wsomf.pdf, wsomf.txt), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:62,500 or smaller.

Geophysics of Martian Periglacial Processes

NASA Technical Reports Server (NTRS)

Mellon, Michael T.

2004-01-01

Through the examination of small-scale geologic features potentially related to water and ice in the martian subsurface (specifically small-scale polygonal ground and young gully-like features), determine the state, distribution and recent history of subsurface water and ice on Mars. To refine existing models and develop new models of near-surface water and ice, and develop new insights about the nature of water on Mars as manifested by these geologic features. Through an improved understanding of potentially water-related geologic features, utilize these features in addressing questions about where to best search for present day water and what space craft may encounter that might facilitate or inhibit the search for water.

Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators.

PubMed

Pimiento, Catalina; Balk, Meghan A

2015-06-01

The extinct shark Carcharocles megalodon is one of the largest marine apex predators ever to exist. Nonetheless, little is known about its body-size variations through time and space. Here, we studied the body-size trends of C. megalodon through its temporal and geographic range to better understand its ecology and evolution. Given that this species was the last of the megatooth lineage, a group of species that shows a purported size increase through time, we hypothesized that C. megalodon also displayed this trend, increasing in size over time and reaching its largest size prior to extinction. We found that C. megalodon body-size distribution was left-skewed (suggesting a long-term selective pressure favoring larger individuals), and presented significant geographic variation (possibly as a result of the heterogeneous ecological constraints of this cosmopolitan species) over geologic time. Finally, we found that stasis was the general mode of size evolution of C. megalodon (i.e., no net changes over time), contrasting with the trends of the megatooth lineage and our hypothesis. Given that C. megalodon is a relatively long-lived species with a widely distributed fossil record, we further used this study system to provide a deep-time perspective to the understanding of the body-size trends of marine apex predators. For instance, our results suggest that (1) a selective pressure in predatory sharks for consuming a broader range of prey may favor larger individuals and produce left-skewed distributions on a geologic time scale; (2) body-size variations in cosmopolitan apex marine predators may depend on their interactions with geographically discrete communities; and (3) the inherent characteristics of shark species can produce stable sizes over geologic time, regardless of the size trends of their lineages.

Geothermal Energy Resources of Navy/Marine Corps Installations on the Atlantic and Gulf Coastal Plain.

DTIC Science & Technology

1980-03-01

Geological Survey ( AAPG -USGS) thermal gradient map of North America, at a scale of 1:5,000,000, gives the hypothesized average depth (by contours) in...file reports; USGS topographic and geologic maps; AAPG -USGS special geologic maps; APL/JHU reports; VPI-SU progress re- ports to DOE/DGE; technical

Overview of geology, hydrology, geomorphology, and sediment budget of the Deschutes River Basin, Oregon.

Treesearch

Jim E. O' Connor; Gordon E. Grant; Tana L. Haluska

2003-01-01

Within the Deschutes River basin of central Oregon, the geology, hydrology, and physiography influence geomorphic and ecologic processes at a variety of temporal and spatial scales. Hydrologic and physiographic characteristics of the basin are related to underlying geologic materials. In the southwestern part of the basin, Quaternary volcanism and tectonism has created...

Publications - RI 2001-1B | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS RI 2001-1B Publication Details Title: Geologic map of the Chulitna region, southcentral , M.L., Reifenstuhl, R.R., and Clough, J.G., 2001, Geologic map of the Chulitna region, southcentral of the Chulitna region, southcentral Alaska, scale 1:63,360 (12.0 M) Digital Geospatial Data Digital

Geologic map of the Great Smoky Mountains National Park region, Tennessee and North Carolina

USGS Publications Warehouse

Southworth, Scott; Schultz, Art; Denenny, Danielle

2005-01-01

The geology of the Great Smoky Mountain National Park (GSMNP) region of Tennessee and North Carolina was studied from 1993 to 2003 as part of a cooperative investigation with the National Park Service (NPS). This work has been compiled as a 1:100,000-scale map derived from mapping done at 1:24,000 and 1:62,500 scale. The geologic data are intended to support cooperative investigations with NPS, the development of a new soil map by the Natural Resources Conservation Service, and the All Taxa Biodiversity Inventory (http://www.discoverlifeinamerica.org/). At the request of NPS, we mapped areas previously not visited, revised the geology where stratigraphic and structural problems existed, and developed a map database for use in interdisciplinary research, land management, and interpretive programs for park visitors.

Sculpting Mountains: Interactive Terrain Modeling Based on Subsurface Geology.

PubMed

Cordonnier, Guillaume; Cani, Marie-Paule; Benes, Bedrich; Braun, Jean; Galin, Eric

2018-05-01

Most mountain ranges are formed by the compression and folding of colliding tectonic plates. Subduction of one plate causes large-scale asymmetry while their layered composition (or stratigraphy) explains the multi-scale folded strata observed on real terrains. We introduce a novel interactive modeling technique to generate visually plausible, large scale terrains that capture these phenomena. Our method draws on both geological knowledge for consistency and on sculpting systems for user interaction. The user is provided hands-on control on the shape and motion of tectonic plates, represented using a new geologically-inspired model for the Earth crust. The model captures their volume preserving and complex folding behaviors under collision, causing mountains to grow. It generates a volumetric uplift map representing the growth rate of subsurface layers. Erosion and uplift movement are jointly simulated to generate the terrain. The stratigraphy allows us to render folded strata on eroded cliffs. We validated the usability of our sculpting interface through a user study, and compare the visual consistency of the earth crust model with geological simulation results and real terrains.

Geologic map of the Themis Regio quadrangle (V-53), Venus

USGS Publications Warehouse

Stofan, Ellen R.; Brian, Antony W.

2012-01-01

The Themis Regio quadrangle (V-53), Venus, has been geologically mapped at 1:5,000,000 scale as part of the NASA Planetary Geologic Mapping Program. The quadrangle extends from lat 25° to 50° S. and from long 270° to 300° E. and encompasses the Themis Regio highland, the surrounding plains, and the southernmost extension of Parga Chasmata. Themis Regio is a broad regional topographic high with a diameter of about 2,000 km and a height of about 0.5 km that has been interpreted previously as a hotspot underlain by a mantle plume. The Themis rise is dominated by coronae and lies at the terminus of the Parga Chasmata corona chain. Themis Regio is the only one of the three corona-dominated rises that contains significant extensional deformation. Fractures and grabens are much less common than along the rest of Parga Chasmata and are embayed by corona-related flows in places. Rift and corona formation has overlapped in time at Themis Regio.

Development of performance assessment methodology for nuclear waste isolation in geologic media

NASA Astrophysics Data System (ADS)

Bonano, E. J.; Chu, M. S. Y.; Cranwell, R. M.; Davis, P. A.

The burial of nuclear wastes in deep geologic formations as a means for their disposal is an issue of significant technical and social impact. The analysis of the processes involved can be performed only with reliable mathematical models and computer codes as opposed to conducting experiments because the time scales associated are on the order of tens of thousands of years. These analyses are concerned primarily with the migration of radioactive contaminants from the repository to the environment accessible to humans. Modeling of this phenomenon depends on a large number of other phenomena taking place in the geologic porous and/or fractured medium. These are ground-water flow, physicochemical interactions of the contaminants with the rock, heat transfer, and mass transport. Once the radionuclides have reached the accessible environment, the pathways to humans and health effects are estimated. A performance assessment methodology for a potential high-level waste repository emplaced in a basalt formation has been developed for the U.S. Nuclear Regulatory Commission.

Regional stratigraphy and subsurface geology of Cenozoic deposits, Gulf Coastal Plain, south-central United States

USGS Publications Warehouse

Hosman, R.L.

1991-01-01

Although Cenozoic deposits are not uniformly differentiated, interstate correlations of major Paleocene and Eocene units are generally established throughout the area. Younger deposits are not as well differentiated. Some stratigraphic designations made at surface exposures cannot be extended into the sub-surface, and the scarcity of distinct geologic horizons has hampered differentiation on a regional scale. The complexities of facies development in Oligocene and younger coastal deposits preclude the development of extensive recognizable horizons needed for stratigraphic applications. Coastal deposits are a heterogeneous assemblage of deltaic, lagoonal, lacustrine, palustrine, eolian, and fluvial clastic facies and local calcareous reef facies. Even major time boundaries, as between geologic series, are not fully resolved. Surficial Quaternary deposits overlie the truncated subcrops of Tertiary strata and generally are distinguishable, although some contacts between Pleistocene and underlying Pliocene deposits have been a ?lstoncal source of controversy. Glacially related terraces are characteristic of the Pleistocene Epoch, and alluvium of aggrading streams typifies the Holocene. 

Report of the USGS Coastal and Marine Geology Modeling Workshop, Pacific Marine Science Center, Santa Cruz, CA, March 22-23, 2005

USGS Publications Warehouse

Sherwood, Christopher R.

2006-01-01

A U.S. Geological Survey (USGS) Coastal and Marine Geology (CMG) Modeling Workshop was held to discuss the general topic of coastal modeling, defined broadly to include circulation, waves, sediment transport, water quality, ecology, sediment diagenesis, morphology change, and coastal evolution, on scales ranging from seconds and a few centimeters (individual ripples) to centuries (coastal evolution) and thousands of kilometers (tsunami propagation). The workshop was convened at the suggestion of CMG Program Management to improve communication among modelers and model users, assess modeling-related activities being conducted at the three centers (Florida Integrated Science Center, FISC; Pacific Marine Science Center; PMSC; and Woods Hole Science Center; WHSC), and develop goals, strategies, and plans for future modeling activities. The workshop represents a step toward developing a five-year strategic plan, and was timed to provide input for the FY06 prospectus. The workshop was held at the USGS Pacific Marine Science Center in Santa Cruz on March 22-23, 2005.

New geologic mapping of the northwestern Willamette Valley, Oregon, and its American Viticultural Areas (AVAs)—A foundation for understanding their terroir

USGS Publications Warehouse

Wells, Ray E.; Haugerud, Ralph A.; Niem, Alan; Niem, Wendy; Ma, Lina; Madin, Ian; Evarts, Russell C.

2018-04-10

A geologic map of the greater Portland, Oregon, metropolitan area is planned that will document the region’s complex geology (currently in review: “Geologic map of the greater Portland metropolitan area and surrounding region, Oregon and Washington,” by Wells, R.E., Haugerud, R.A., Niem, A., Niem, W., Ma, L., Evarts, R., Madin, I., and others). The map, which is planned to be published as a U.S. Geological Survey Scientific Investigations Map, will consist of 51 7.5′ quadrangles covering more than 2,500 square miles, and it will represent more than 100 person-years of geologic mapping and studies. The region was mapped at the relatively detailed scale of 1:24,000 to improve understanding of its geology and its earthquake hazards. More than 100 geologic map units will record the 50-million-year history of volcanism, sedimentation, folding, and faulting above the Cascadia Subduction Zone. The geology contributes to the varied terroir of four American Viticultural Areas (AVAs) in the northwestern Willamette Valley: the Yamhill-Carlton, Dundee Hills, Chehalem Mountains, and Ribbon Ridge AVAs. Terroir is defined as the environmental conditions, especially climate and soils, that influence the quality and character of a region’s crops—in this case, grapes for wine.On this new poster (“New geologic mapping of the northwestern Willamette Valley, Oregon, and its American Viticultural Areas (AVAs)—A foundation for understanding their terroir”), we present the geologic map at a reduced scale (about 1:175,000) to show the general distribution of geologic map units, and we highlight, discuss, and illustrate six major geologic events that helped shape the region and form its terrior. We also discuss the geologic elements that contribute to the character of each of the four AVAs in the northwestern Willamette Valley.

A recipe for consistent 3D management of velocity data and time-depth conversion using Vel-IO 3D

NASA Astrophysics Data System (ADS)

Maesano, Francesco E.; D'Ambrogi, Chiara

2017-04-01

3D geological model production and related basin analyses need large and consistent seismic dataset and hopefully well logs to support correlation and calibration; the workflow and tools used to manage and integrate different type of data control the soundness of the final 3D model. Even though seismic interpretation is a basic early step in such workflow, the most critical step to obtain a comprehensive 3D model useful for further analyses is represented by the construction of an effective 3D velocity model and a well constrained time-depth conversion. We present a complex workflow that includes comprehensive management of large seismic dataset and velocity data, the construction of a 3D instantaneous multilayer-cake velocity model, the time-depth conversion of highly heterogeneous geological framework, including both depositional and structural complexities. The core of the workflow is the construction of the 3D velocity model using Vel-IO 3D tool (Maesano and D'Ambrogi, 2017; https://github.com/framae80/Vel-IO3D) that is composed by the following three scripts, written in Python 2.7.11 under ArcGIS ArcPy environment: i) the 3D instantaneous velocity model builder creates a preliminary 3D instantaneous velocity model using key horizons in time domain and velocity data obtained from the analysis of well and pseudo-well logs. The script applies spatial interpolation to the velocity parameters and calculates the value of depth of each point on each horizon bounding the layer-cake velocity model. ii) the velocity model optimizer improves the consistency of the velocity model by adding new velocity data indirectly derived from measured depths, thus reducing the geometrical uncertainties in the areas located far from the original velocity data. iii) the time-depth converter runs the time-depth conversion of any object located inside the 3D velocity model The Vel-IO 3D tool allows one to create 3D geological models consistent with the primary geological constraints (e.g. depth of the markers on wells). The workflow and Vel-IO 3D tool have been developed and tested for the construction of the 3D geological model of a flat region, 5700 km2 in area, located in the central part of the Po Plain (Northern Italy) in the frame of the European funded Project GeoMol. The study area was covered by a dense dataset of seismic lines (ca. 12000 km) and exploration wells (130 drilling), mainly deriving from oil and gas exploration activities. The interpretation of the seismic dataset leads to the construction of a 3D model in time domain that has been depth converted using Vel-IO 3D, with a 4 layer-cake 3D instantaneous velocity model. The resulting final 3D geological model, composed of 15 horizons and 150 faults, has been used for basin analysis at regional scale, for geothermal assessment, and for the update of the seismotectonic knowledge of the Po Plain. The Vel-IO 3D has been further used for the depth conversion of the accretionary prism of the Calabrian subduction (Southern Italy) and for a basin scale analysis of the Po Plain Plio-Pleistocene evolution. Maesano F.E. and D'Ambrogi C., (2017), Computers and Geosciences, doi: 10.1016/j.cageo.2016.11.013 Vel-IO 3D is available at: https://github.com/framae80/Vel-IO3D

Publications - PIR 2004-3B | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS PIR 2004-3B Publication Details Title: Bedrock geologic map of the Livengood SW C-3 and SE C ., Newberry, R.J., Werdon, M.B., and Hicks, S.A., 2004, Bedrock geologic map of the Livengood SW C-3 and SE C geologic map of the Livengood SW C-3 and SE C-4 quadrangles, Tolovana mining district, Alaska, scale 1

Spatial Digital Database for the Geologic Map of Oregon

USGS Publications Warehouse

Walker, George W.; MacLeod, Norman S.; Miller, Robert J.; Raines, Gary L.; Connors, Katherine A.

2003-01-01

Introduction This report describes and makes available a geologic digital spatial database (orgeo) representing the geologic map of Oregon (Walker and MacLeod, 1991). The original paper publication was printed as a single map sheet at a scale of 1:500,000, accompanied by a second sheet containing map unit descriptions and ancillary data. A digital version of the Walker and MacLeod (1991) map was included in Raines and others (1996). The dataset provided by this open-file report supersedes the earlier published digital version (Raines and others, 1996). This digital spatial database is one of many being created by the U.S. Geological Survey as an ongoing effort to provide geologic information for use in spatial analysis in a geographic information system (GIS). This database can be queried in many ways to produce a variety of geologic maps. This database is not meant to be used or displayed at any scale larger than 1:500,000 (for example, 1:100,000). This report describes the methods used to convert the geologic map data into a digital format, describes the ArcInfo GIS file structures and relationships, and explains how to download the digital files from the U.S. Geological Survey public access World Wide Web site on the Internet. Scanned images of the printed map (Walker and MacLeod, 1991), their correlation of map units, and their explanation of map symbols are also available for download.

The key to commercial-scale geological CO2 sequestration: Displaced fluid management

USGS Publications Warehouse

Surdam, R.C.; Jiao, Z.; Stauffer, P.; Miller, T.

2011-01-01

The Wyoming State Geological Survey has completed a thorough inventory and prioritization of all Wyoming stratigraphic units and geologic sites capable of sequestering commercial quantities of CO2 (5-15 Mt CO 2/year). This multi-year study identified the Paleozoic Tensleep/Weber Sandstone and Madison Limestone (and stratigraphic equivalent units) as the leading clastic and carbonate reservoir candidates for commercial-scale geological CO2 sequestration in Wyoming. This conclusion was based on unit thickness, overlying low permeability lithofacies, reservoir storage and continuity properties, regional distribution patterns, formation fluid chemistry characteristics, and preliminary fluid-flow modeling. This study also identified the Rock Springs Uplift in southwestern Wyoming as the most promising geological CO2 sequestration site in Wyoming and probably in any Rocky Mountain basin. The results of the WSGS CO2 geological sequestration inventory led the agency and colleagues at the UW School of Energy Resources Carbon Management Institute (CMI) to collect available geologic, petrophysical, geochemical, and geophysical data on the Rock Springs Uplift, and to build a regional 3-D geologic framework model of the Uplift. From the results of these tasks and using the FutureGen protocol, the WSGS showed that on the Rock Springs Uplift, the Weber Sandstone has sufficient pore space to sequester 18 billion tons (Gt) of CO2, and the Madison Limestone has sufficient pore space to sequester 8 Gt of CO2. ?? 2011 Published by Elsevier Ltd.

Solute transport in crystalline rocks at Aspö--I: geological basis and model calibration.

PubMed

Mazurek, Martin; Jakob, Andreas; Bossart, Paul

2003-03-01

Water-conducting faults and fractures were studied in the granite-hosted Aspö Hard Rock Laboratory (SE Sweden). On a scale of decametres and larger, steeply dipping faults dominate and contain a variety of different fault rocks (mylonites, cataclasites, fault gouges). On a smaller scale, somewhat less regular fracture patterns were found. Conceptual models of the fault and fracture geometries and of the properties of rock types adjacent to fractures were derived and used as input for the modelling of in situ dipole tracer tests that were conducted in the framework of the Tracer Retention Understanding Experiment (TRUE-1) on a scale of metres. After the identification of all relevant transport and retardation processes, blind predictions of the breakthroughs of conservative to moderately sorbing tracers were calculated and then compared with the experimental data. This paper provides the geological basis and model calibration, while the predictive and inverse modelling work is the topic of the companion paper [J. Contam. Hydrol. 61 (2003) 175]. The TRUE-1 experimental volume is highly fractured and contains the same types of fault rocks and alterations as on the decametric scale. The experimental flow field was modelled on the basis of a 2D-streamtube formalism with an underlying homogeneous and isotropic transmissivity field. Tracer transport was modelled using the dual porosity medium approach, which is linked to the flow model by the flow porosity. Given the substantial pumping rates in the extraction borehole, the transport domain has a maximum width of a few centimetres only. It is concluded that both the uncertainty with regard to the length of individual fractures and the detailed geometry of the network along the flowpath between injection and extraction boreholes are not critical because flow is largely one-dimensional, whether through a single fracture or a network. Process identification and model calibration were based on a single uranine breakthrough (test PDT3), which clearly showed that matrix diffusion had to be included in the model even over the short experimental time scales, evidenced by a characteristic shape of the trailing edge of the breakthrough curve. Using the geological information and therefore considering limited matrix diffusion into a thin fault gouge horizon resulted in a good fit to the experiment. On the other hand, fresh granite was found not to interact noticeably with the tracers over the time scales of the experiments. While fracture-filling gouge materials are very efficient in retarding tracers over short periods of time (hours-days), their volume is very small and, with time progressing, retardation will be dominated by altered wall rock and, finally, by fresh granite. In such rocks, both porosity (and therefore the effective diffusion coefficient) and sorption K(d)s are more than one order of magnitude smaller compared to fault gouge, thus indicating that long-term retardation is expected to occur but to be less pronounced. Copyright 2002 Elsevier Science B.V.

Spatiotemporal Thinking in the Geosciences

NASA Astrophysics Data System (ADS)

Shipley, T. F.; Manduca, C. A.; Ormand, C. J.; Tikoff, B.

2011-12-01

Reasoning about spatial relations is a critical skill for geoscientists. Within the geosciences different disciplines may reason about different sorts of relationships. These relationships may span vastly different spatial and temporal scales (from the spatial alignment in atoms in crystals to the changes in the shape of plates). As part of work in a research center on spatial thinking in STEM education, we have been working to classify the spatial skills required in geology, develop tests for each spatial skill, and develop the cognitive science tools to promote the critical spatial reasoning skills. Research in psychology, neurology and linguistics supports a broad classification of spatial skills along two dimensions: one versus many objects (which roughly translates to object- focused and navigation focused skills) and static versus dynamic spatial relations. The talk will focus on the interaction of space and time in spatial cognition in the geosciences. We are working to develop measures of skill in visualizing spatiotemporal changes. A new test developed to measure visualization of brittle deformations will be presented. This is a skill that has not been clearly recognized in the cognitive science research domain and thus illustrates the value of interdisciplinary work that combines geosciences with cognitive sciences. Teaching spatiotemporal concepts can be challenging. Recent theoretical work suggests analogical reasoning can be a powerful tool to aid student learning to reason about temporal relations using spatial skills. Recent work in our lab has found that progressive alignment of spatial and temporal scales promotes accurate reasoning about temporal relations at geological time scales.

Preliminary integrated geologic map databases for the United States : Central states : Montana, Wyoming, Colorado, New Mexico, Kansas, Oklahoma, Texas, Missouri, Arkansas, and Louisiana

USGS Publications Warehouse

Stoeser, Douglas B.; Green, Gregory N.; Morath, Laurie C.; Heran, William D.; Wilson, Anna B.; Moore, David W.; Van Gosen, Bradley S.

2005-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and lithology information. Such maps can be conveniently used to generate derivative maps for purposes including mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This Open-File Report is a preliminary version of part of a series of integrated state geologic map databases that cover the entire United States. The only national-scale digital geologic maps that portray most or all of the United States for the conterminous U.S. are the digital version of the King and Beikman (1974a, b) map at a scale of 1:2,500,000, as digitized by Schruben and others (1994) and the digital version of the Geologic Map of North America (Reed and others, 2005a, b) compiled at a scale of 1:5,000,000 which is currently being prepared by the U.S. Geological Survey. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. In a few cases, new digital compilations were prepared (e.g. OH, SC, SD) or existing paper maps were digitized (e.g. KY, TX). For Alaska and Hawaii, new regional maps are being compiled and ultimately new state maps will be produced. The digital geologic maps are presented in standardized formats as ARC/INFO (.e00) export files and as ArcView shape (.shp) files. Accompanying these spatial databases are a set of five supplemental data tables that relate the map units to detailed lithologic and age information. The maps for the CONUS have been fitted to a common set of state boundaries based on the 1:100,000 topographic map series of the United States Geological Survey (USGS). When the individual state maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps. No attempt has been made to reconcile differences in mapped geology across state lines. This is the first version of this product and it will be subsequently updated to include four additional states (North Dakota, South Dakota, Nebraska, and Iowa)

Geologic Map of the Thaumasia Region, Mars

USGS Publications Warehouse

Dohm, Janes M.; Tanaka, Kenneth L.; Hare, Trent M.

2001-01-01

The geology of the Thaumasia region (fig. 1, sheet 3) includes a wide array of rock materials, depositional and erosional landforms, and tectonic structures. The region is dominated by the Thaumasia plateau, which includes central high lava plains ringed by highly deformed highlands; the plateau may comprise the ancestral center of Tharsis tectonism (Frey, 1979; Plescia and Saunders, 1982). The extensive structural deformation of the map region, which is without parallel on Mars in both complexity and diversity, occurred largely throughout the Noachian and Hesperian periods (Tanaka and Davis, 1988; Scott and Dohm, 1990a). The deformation produced small and large extensional and contractional structures (fig. 2, sheet 3) that resulted from stresses related to the formation of Tharsis (Frey, 1979; Wise and others, 1979; Plescia and Saunders, 1982; Banerdt and others, 1982, 1992; Watters and Maxwell, 1986; Tanaka and Davis, 1988; Francis, 1988; Watters, 1993; Schultz and Tanaka, 1994), from magmatic-driven uplifts, such as at Syria Planum (Tanaka and Davis, 1988; Dohm and others, 1998; Dohm and Tanaka, 1999) and central Valles Marineris (Dohm and others, 1998, Dohm and Tanaka, 1999), and from the Argyre impact (Wilhelms, 1973; Scott and Tanaka, 1986). In addition, volcanic, eolian, and fluvial processes have highly modified older surfaces in the map region. Local volcanic and tectonic activity often accompanied episodes of valley formation. Our mapping depicts and describes the diverse terrains and complex geologic history of this unique ancient tectonic region of Mars. The geologic (sheet 1), paleotectonic (sheet 2), and paleoerosional (sheet 3) maps of the Thaumasia region were compiled on a Viking 1:5,000,000-scale digital photomosaic base. The base is a combination of four quadrangles: the southeast part of Phoenicis Lacus (MC–17), most of the southern half of Coprates (MC–18), a large part of Thaumasia (MC–25), and the northwest margin of Argyre (MC–26). The medium-resolution Viking images used for mapping and base preparation also formed the basis of the 1:2,000,000 scale subquadrangle series. Earlier geologic maps of all or parts of the region include: (1) maps of the Phoenicis Lacus, Coprates, Thaumasia, and Argyre quadrangles at 1:5,000,000 scale based mainly on Mariner 9 images (respectively, Masursky and others, 1978; McCauley, 1978; McGill, 1978; and Hodges, 1980), (2) the global map of Mars at 1:25,000,000 (Scott and Carr, 1978) compiled largely from the 1:5,000,000 scale geologic maps, (3) maps showing lava flows in the Tharsis region at 1:2,000,000 scale compiled from Viking and Mariner 9 images (Scott, 1981; Scott and Tanaka, 1981a, b; Scott and others, 1981), (4) the map of the western equatorial region of Mars at 1:15,000,000 scale based on Viking images (Scott and Tanaka, 1986), and (5) the map of the Valles Marineris region at 1:2,000,000 scale compiled from Viking images (Witbeck and others, 1991). The previous maps have described the overall geology and geomorphology of the region but have not unraveled the detailed stratigraphy and complex evolution of this unique and geologically diverse martian province. The main purpose of this comprehensive mapping project is to reconstruct the stratigraphic, structural, and erosional histories of the Thaumasia region. The region is the last major province of the Tharsis region to undergo detailed structural mapping using Viking images; its history is essential to documenting the overall tectonic history of Tharsis. Other provinces of Tharsis that have been structurally mapped include Syria Planum (Tanaka and Davis, 1988), Tempe Terra and Ulysses Patera (Scott and Dohm, 1990b), and Alba Patera (Tanaka, 1990). Another primary mapping objective is to determine the region's volcanic history and assess the relations among fault systems and volcanoes (Wise and others, 1979; Scott and Tanaka, 1980; Whitford-Stark, 1982; Scott and Dohm, 1990a). A secondary mapping objective is to determine the distribution and ages of valleys. In our study, we incorporated detailed photogeologic mapping, comprehensive crater statistics (table 1), and geologic, paleotectonic, and paleoerosional Geographic Information System (GIS) databases. Sheets 1–3 show geologic units, faults and other significant structures, and valleys, respectively. To help unravel the complex geologic history of the Thaumasia region, we transferred the highly detailed geologic unit, paleotectonic, and paleoerosional information of sheets 1–3 into a multilayered GIS database for comparative analysis. The geologic information was transferred from hard copy into a digital format by scanning at 25 micron resolution on a drum scanner. The 2-bit scanned image was then converted to an x,y coordinate system using ARC/INFO's vectorization routine. The geologic unit, structural, and erosional data were transformed into the original map projection, Lambert Conformal. The average transformation root mean square error was 0.25 km (acceptable for the Thaumasia map base at 1:5,000,000 scale). After transformation, the features were properly attributed and tediously checked. Once digitized, the map data can be transformed into any map projection depending on the type of data analysis. For example, the equal-area sinusoidal projection was used for determining the precise area of geologic units (table 1). In addition to the geologic map and its attendant stratigraphic section, correlation chart, and description of map units, we include text sections that clarify the histories and temporal, spatial, and causal relations of the various geologic units and landforms of the Thaumasia region. The geologic summary section defines the sequence of major geologic events.

Map scale effects on estimating the number of undiscovered mineral deposits

USGS Publications Warehouse

Singer, D.A.; Menzie, W.D.

2008-01-01

Estimates of numbers of undiscovered mineral deposits, fundamental to assessing mineral resources, are affected by map scale. Where consistently defined deposits of a particular type are estimated, spatial and frequency distributions of deposits are linked in that some frequency distributions can be generated by processes randomly in space whereas others are generated by processes suggesting clustering in space. Possible spatial distributions of mineral deposits and their related frequency distributions are affected by map scale and associated inclusions of non-permissive or covered geological settings. More generalized map scales are more likely to cause inclusion of geologic settings that are not really permissive for the deposit type, or that include unreported cover over permissive areas, resulting in the appearance of deposit clustering. Thus, overly generalized map scales can cause deposits to appear clustered. We propose a model that captures the effects of map scale and the related inclusion of non-permissive geologic settings on numbers of deposits estimates, the zero-inflated Poisson distribution. Effects of map scale as represented by the zero-inflated Poisson distribution suggest that the appearance of deposit clustering should diminish as mapping becomes more detailed because the number of inflated zeros would decrease with more detailed maps. Based on observed worldwide relationships between map scale and areas permissive for deposit types, mapping at a scale with twice the detail should cut permissive area size of a porphyry copper tract to 29% and a volcanic-hosted massive sulfide tract to 50% of their original sizes. Thus some direct benefits of mapping an area at a more detailed scale are indicated by significant reductions in areas permissive for deposit types, increased deposit density and, as a consequence, reduced uncertainty in the estimate of number of undiscovered deposits. Exploration enterprises benefit from reduced areas requiring detailed and expensive exploration, and land-use planners benefit from reduced areas of concern. ?? 2008 International Association for Mathematical Geology.

Geology of Point Reyes National Seashore and vicinity, California: a digital database

USGS Publications Warehouse

Clark, Jospeh C.; Brabb, Earl E.

1997-01-01

This Open-File report is a digital geologic map database. This pamphlet serves to introduce and describe the digital data. There is no paper map included in the Open-File report. The report does include, however, a PostScript plot file containing an image of the geologic map sheet with explanation, as well as the accompanying text describing the geology of the area. For those interested in a paper plot of information contained in the database or in obtaining the PostScript plot files, please see the section entitled 'For Those Who Aren't Familiar With Digital Geologic Map Databases' below. This digital map database, compiled from previously published and unpublished data and new mapping by the authors, represents the general distribution of surficial deposits and rock units in Point Reyes and surrounding areas. Together with the accompanying text file (pr-geo.txt or pr-geo.ps), it provides current information on the stratigraphy and structural geology of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:48,000 or smaller.

A proposal to conduct a Caribbean plate project involving the application of space technology to the study of Caribbean geology

NASA Technical Reports Server (NTRS)

Wadge, G. (Editor)

1981-01-01

The Caribbean plate project is designed to improve current understanding of geological resources and geological hazards within the Caribbean region. Models of mineral occurrence and genesis (including energy resources) on a regional scale, which contribute to nonrenewable resource investigations. Models of lithospheric stress and strain on a regional scale, which contribute to forecasting geological hazards such as earthquakes and major volcanic eruptions are developed. Geological information is synthesize, and research tools provided by space technology the study of the Earth's crust are used. The project was organized in a thematic fashion, to focus on specific geological aspects of the Caribbean plate which are considered to be key factors in developing the types of models described. The project adopts a synoptic perspective in seeking to characterize the three dimensional structure, composition, state of stress, and evolution of the entire Caribbean plate. Geological information derived from analysis of space acquired data is combined with information provided by conventional methods to obtain insight into the structure, composition, and evolution of the Earth's crust. In addition, very long baseline interferometry and laser ranging techniques, which are also based upon the use of space technology, obtain information concerning crustal motion that, in turn, provides insight into the distribution and localization of crustal stress.

The Study of Effects of Time Variations in the Earth's Gravity Field on Geodetic Satellites

NASA Technical Reports Server (NTRS)

Shum, C. K.

1998-01-01

The temporal variations in the Earth's gravity field are the consequences of complex interactions between atmosphere, ocean, solid Earth, hydrosphere and cryosphere. The signal ranges from several hours to 18.6 years to geological time scale. The direct and indirect consequences of these variations are manifested in such phenomena as changes in the global sea level and in the global climate pattern. These signals produce observable geodetic satellites. The primary objectives of the proposed effects on near-Earth orbiting investigation include (1) the improved determination of the time-varying gravity field parameters (scale from a few hour to 18.6 year and secular) using long-term satellite laser rs ranging (SLR) observations to multiple geodetic satellites, and (2) the enhanced understanding of these variations with their associated meteorological and geophysical consequences.

Measuring Student Knowledge of Landscapes and Their Formation Timespans

ERIC Educational Resources Information Center

Jolley, Alison; Jones, Francis; Harris, Sara

2013-01-01

Geologic time is a crucial component of any geoscientist's training. Essential knowledge of geologic time includes rates of geologic processes and the associated time it takes for geologic features to form, yet measuring conceptual thinking abilities in these domains is challenging. We describe development and initial application of the Landscape…

Measuring Student Understanding of Geological Time

ERIC Educational Resources Information Center

Dodick, Jeff; Orion, Nir

2003-01-01

There have been few discoveries in geology more important than "deep time"--the understanding that the universe has existed for countless millennia, such that man's existence is confined to the last milliseconds of the metaphorical geological clock. The influence of deep time is felt in a variety of sciences including geology, cosmology,…

Geological mapping of the moon

NASA Technical Reports Server (NTRS)

Markov, M. S.; Sukhanov, A. L.; Trifonov, V. G.; Florenskiy, P. V.; Shkerin, L. M.

1974-01-01

Compilation and labelling of geological and morphological charts on a scale of 1:1,000,000 are discussed with emphasis on the regions of Maria Tranquilitatis, Crisium, Fecunditatis, Humorum and Nukium as well as certain prominent craters.

Students' Understanding of Large Numbers as a Key Factor in Their Understanding of Geologic Time

ERIC Educational Resources Information Center

Cheek, Kim A.

2012-01-01

An understanding of geologic time is comprised of 2 facets. Events in Earth's history can be placed in relative and absolute temporal succession on a vast timescale. Rates of geologic processes vary widely, and some occur over time periods well outside human experience. Several factors likely contribute to an understanding of geologic time, one of…

Will Somebody do the Dishes? Weathering Analogies, Geologic Processes and Geologic Time

NASA Astrophysics Data System (ADS)

Stelling, P.; Wuotila, S.; Giuliani, M.

2006-12-01

A good analogy is one of the most powerful tools in any instructors' arsenal, and encouraging students to explore the links between an analogy and a scientific concept can cement both ideas in a student's mind. A common analogy for weathering and erosion processes is doing the dishes. Oxidation, hydration, and solution reactions can be intimidating on the chalkboard but easily understood in the context of cleaning up after dinner. Rather than present this analogy as a lecture demonstration, students are encouraged to experimentally determine which type of weathering works best on their dirty dishes. The experiment must use at least four identically dirty dishes: three experimental dishes and one control dish. The experimental dishes are subjected to simulated weathering and erosion processes of the student's design. Common techniques developed by students are cold or warm water baths, baths with and without acid (lemon juice or soda), and freeze-thaw cycles. Occasionally creative experiments result in unexpected discoveries, such the inefficiency of abrasion from wind-blown sand, especially when compared to soaking dishes in Canadian Whiskey. The effectiveness of each experimental run is determined by comparison to the control plate after loose debris is removed from each. The dish with the smallest aerial extent of remaining food is the declared the most effective. Discussion sections of the experimental write-up includes a description of which geologic processes were being simulated in each experiment, comparisons of the effectiveness of each techniques, and statements of how these experiments differ from reality. In order to advance this project, a second stage of the assignment, a direct comparison of weathering and erosion techniques on food and on geologic materials, will be added this fall. Ideally, students will empirically derive erosion rates and calculate the time required to remove the volume of material represented by a geologically important feature, such as Mt. Rainier or the Grand Canyon. In the end, students completing this project gain an understanding of how geologic processes work, the time scales required, the differences between analogies and the real thing, and arguably the most important aspect, a best-practices approach to doing the dishes.

From spatially variable streamflow to distributed hydrological models: Analysis of key modeling decisions

NASA Astrophysics Data System (ADS)

Fenicia, Fabrizio; Kavetski, Dmitri; Savenije, Hubert H. G.; Pfister, Laurent

2016-02-01

This paper explores the development and application of distributed hydrological models, focusing on the key decisions of how to discretize the landscape, which model structures to use in each landscape element, and how to link model parameters across multiple landscape elements. The case study considers the Attert catchment in Luxembourg—a 300 km2 mesoscale catchment with 10 nested subcatchments that exhibit clearly different streamflow dynamics. The research questions are investigated using conceptual models applied at hydrologic response unit (HRU) scales (1-4 HRUs) on 6 hourly time steps. Multiple model structures are hypothesized and implemented using the SUPERFLEX framework. Following calibration, space/time model transferability is tested using a split-sample approach, with evaluation criteria including streamflow prediction error metrics and hydrological signatures. Our results suggest that: (1) models using geology-based HRUs are more robust and capture the spatial variability of streamflow time series and signatures better than models using topography-based HRUs; this finding supports the hypothesis that, in the Attert, geology exerts a stronger control than topography on streamflow generation, (2) streamflow dynamics of different HRUs can be represented using distinct and remarkably simple model structures, which can be interpreted in terms of the perceived dominant hydrologic processes in each geology type, and (3) the same maximum root zone storage can be used across the three dominant geological units with no loss in model transferability; this finding suggests that the partitioning of water between streamflow and evaporation in the study area is largely independent of geology and can be used to improve model parsimony. The modeling methodology introduced in this study is general and can be used to advance our broader understanding and prediction of hydrological behavior, including the landscape characteristics that control hydrologic response, the dominant processes associated with different landscape types, and the spatial relations of catchment processes. This article was corrected on 14 MAR 2016. See the end of the full text for details.

A framework for predicting global silicate weathering and CO2 drawdown rates over geologic time-scales.

PubMed

Hilley, George E; Porder, Stephen

2008-11-04

Global silicate weathering drives long-time-scale fluctuations in atmospheric CO(2). While tectonics, climate, and rock-type influence silicate weathering, it is unclear how these factors combine to drive global rates. Here, we explore whether local erosion rates, GCM-derived dust fluxes, temperature, and water balance can capture global variation in silicate weathering. Our spatially explicit approach predicts 1.9-4.6 x 10(13) mols of Si weathered globally per year, within a factor of 4-10 of estimates of global silicate fluxes derived from riverine measurements. Similarly, our watershed-based estimates are within a factor of 4-18 (mean of 5.3) of the silica fluxes measured in the world's ten largest rivers. Eighty percent of total global silicate weathering product traveling as dissolved load occurs within a narrow range (0.01-0.5 mm/year) of erosion rates. Assuming each mol of Mg or Ca reacts with 1 mol of CO(2), 1.5-3.3 x 10(8) tons/year of CO(2) is consumed by silicate weathering, consistent with previously published estimates. Approximately 50% of this drawdown occurs in the world's active mountain belts, emphasizing the importance of tectonic regulation of global climate over geologic timescales.

Numerical Simulation of Potential Groundwater Contaminant Pathways from Hydraulically Fractured Oil Shale in the Nevada Basin and Range Province

NASA Astrophysics Data System (ADS)

Rybarski, S.; Pohll, G.; Pohlmann, K.; Plume, R.

2014-12-01

In recent years, hydraulic fracturing (fracking) has become an increasingly popular method for extraction of oil and natural gas from tight formations. Concerns have been raised over a number of environmental risks associated with fracking, including contamination of groundwater by fracking fluids, upwelling of deep subsurface brines, and methane migration. Given the potentially long time scale for contaminant transport associated with hydraulic fracturing, numerical modeling remains the best practice for risk assessment. Oil shale in the Humboldt basin of northeastern Nevada has now become a target for hydraulic fracturing operations. Analysis of regional and shallow groundwater flow is used to assess several potential migration pathways specific to the geology and hydrogeology of this basin. The model domain in all simulations is defined by the geologic structure of the basin as determined by deep oil and gas well bores and formation outcrops. Vertical transport of gaseous methane along a density gradient is simulated in TOUGH2, while fluid transport along faults and/or hydraulic fractures and lateral flow through more permeable units adjacent to the targeted shale are modeled in FEFLOW. Sensitivity analysis considers basin, fault, and hydraulic fracturing parameters, and results highlight key processes that control fracking fluid and methane migration and time scales under which it might occur.

Effects on the mobility of metals from acidification caused by possible CO₂ leakage from sub-seabed geological formations.

PubMed

de Orte, Manoela Romanó; Sarmiento, Aguasanta M; Basallote, Maria Dolores; Rodríguez-Romero, Araceli; Riba, Inmaculada; Delvalls, Angel

2014-02-01

Carbon dioxide capture and storage (CCS) in submarine geological formations has been proposed as a mitigation measure for the prevention of global warming. However, leakage of CO2 to overlying sediments may occur over time, leading to various effects on ecosystems. Laboratory-scale experiments were performed, involving direct release of carbon dioxide into sediment, inside non-pressurized chambers, in order to provide data on the possible effects of CO2 leakage from geological storage sites on the fate of several metals. Marine sediments from three sites with different levels of contamination were sampled and submitted to acidification by means of CO2 injection. The experiment lasted 10 days and sediment samples were collected at the beginning and end of the experiment and pore water was extracted for metal analysis. The results revealed that mobility of metals from sediment to pore water depends on the site, metal and length of time exposed. Mobilization of the metals Al, Fe, Zn, Co, Pb and Cu increases with acidification, and this response generally increases with time of exposure to CO2 injection. The geochemical model applied suggests that acidification also influences the speciation of metals, transforming metals and metalloids, like As, into species much more toxic to biota. The data obtained from this study will be useful for calculating the potential risk of CCS activities to the marine environment. © 2013.

Subsurface to substrate: dual-scale micro/nanofluidic networks for investigating transport anomalies in tight porous media.

PubMed

Kelly, Shaina A; Torres-Verdín, Carlos; Balhoff, Matthew T

2016-08-07

Micro/nanofluidic experiments in synthetic representations of tight porous media, often referred to as "reservoir-on-a-chip" devices, are an emerging approach to researching anomalous fluid transport trends in energy-bearing and fluid-sequestering geologic porous media. We detail, for the first time, the construction of dual-scale micro/nanofluidic devices that are relatively large-scale, two-dimensional network representations of granular and fractured nanoporous media. The fabrication scheme used in the development of the networks on quartz substrates (master patterns) is facile and replicable: transmission electron microscopy (TEM) grids with lacey carbon support film were used as shadow masks in thermal evaporation/deposition and reactive ion etch (RIE) was used for hardmask pattern transfer. The reported nanoscale network geometries are heterogeneous and composed of hydraulically resistive paths (throats) meeting at junctures (pores) to mimic the low topological connectivity of nanoporous sedimentary rocks such as shale. The geometry also includes homogenous microscale grid patterns that border the nanoscale networks and represent microfracture pathways. Master patterns were successfully replicated with a sequence of polydimethylsiloxane (PDMS) and Norland Optical Adhesive (NOA) 63 polymers. The functionality of the fabricated quartz and polymer nanofluidic devices was validated with aqueous imbibition experiments and differential interference contrast microscopy. These dual-scale fluidic devices are promising predictive tools for hypothesis testing and calibration against bulk fluid measurements in tight geologic, biologic, and synthetic porous material of similar dual-scale pore structure. Applications to shale/mudrock transport studies in particular are focused on herein.

Publications - RI 97-15B | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS RI 97-15B Publication Details Title: Interpretive geologic bedrock map of the Tanana B-1 ., 1997, Interpretive geologic bedrock map of the Tanana B-1 Quadrangle, central Alaska: Alaska Division bedrock map of the Tanana B-1 Quadrangle, Central Alaska, scale 1:63,360 (8.3 M) Digital Geospatial Data

Geologic map of the eastern part of the Challis National Forest and vicinity, Idaho

USGS Publications Warehouse

Wilson, A.B.; Skipp, B.A.

1994-01-01

The paper version of the Geologic Map of the eastern part of the Challis National Forest and vicinity, Idaho was compiled by Anna Wilson and Betty Skipp in 1994. The geology was compiled on a 1:250,000 scale topographic base map. TechniGraphic System, Inc. of Fort Collins Colorado digitized this map under contract for N.Shock. G.Green edited and prepared the digital version for publication as a GIS database. The digital geologic map database can be queried in many ways to produce a variety of geologic maps.

Large-scale Thermo-Hydro-Mechanical Simulations in Complex Geological Environments

NASA Astrophysics Data System (ADS)

Therrien, R.; Lemieux, J.

2011-12-01

The study of a potential deep repository for radioative waste disposal in Canada context requires simulation capabilities for thermo-hydro-mechanical processes. It is expected that the host rock for the deep repository will be subjected to a variety of stresses during its lifetime such as in situ stresses in the rock, stressed caused by excavation of the repository and thermo-mechanical stresses. Another stress of concern for future Canadian climates will results from various episodes of glaciation. In that case, it can be expected that over 3 km of ice may be present over the land mass, which will create a glacial load that will be transmitted to the underlying geological materials and therefore impact their mechanical and hydraulic responses. Glacial loading will affect pore fluid pressures in the subsurface, which will in turn affect groundwater velocities and the potential migration of radionuclides from the repository. In addition, permafrost formation and thawing resulting from glacial advance and retreat will modify the bulk hydraulic of the geological materials and will have a potentially large impact on groundwater flow patterns, especially groundwater recharge. In the context of a deep geological repository for spent nuclear fuel, the performance of the repository to contain the spent nuclear fuel must be evaluated for periods that span several hundred thousand years. The time-frame for thermo-hydro-mechanical simulations is therefore extremely long and efficient numerical techniques must be developed. Other challenges are the representation of geological formations that have potentially complex geometries and physical properties and may contain fractures. The spatial extent of the simulation domain is also very large and can potentially reach the size of a sedimentary basin. Mass transport must also be considered because the fluid salinity in a sedimentary basin can be highly variable and the effect of fluid density on groundwater flow must be accounted for. Adding mass transport with density effect introduces further non-linearities in the governing equations, thus leading to increased simulation times. We will present challenges and current developments related to this topic in the Canadian context. Current efforts aim at improving simulation capabilities for large-scale 3D thermo-hydro-mechanical simulation in complex geologic materials. One topic of interest is to evaluate the appropriateness of simplifying the effect of glacial loading by using a one-dimensional hydro-mechanical representation that assumes purely vertical strain as opposed to the much more computationally intensive 3D representation.

SECARB Commercial Scale CO 2 Injection and Optimization of Storage Capacity in the Southeastern United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koperna, George J.; Pashin, Jack; Walsh, Peter

The Commercial Scale Project is a US DOE/NETL funded initiative aimed at enhancing the knowledge-base and industry’s ability to geologically store vast quantities of anthropogenic carbon. In support of this goal, a large-scale, stacked reservoir geologic model was developed for Gulf Coast sediments centered on the Citronelle Dome in southwest Alabama, the site of the SECARB Phase III Anthropogenic Test. Characterization of regional geology to construct the model consists of an assessment of the entire stratigraphic continuum at Citronelle Dome, from surface to the depth of the Donovan oil-bearing formation. This project utilizes all available geologic data available, which includes:more » modern geophysical well logs from three new wells drilled for SECARB’s Anthropogenic Test; vintage logs from the Citronelle oilfield wells; porosity and permeability data from whole core and sidewall cores obtained from the injection and observation wells drilled for the Anthropogenic Test; core data obtained from the SECARB Phase II saline aquifer injection test; regional core data for relevant formations from the Geological Survey of Alabama archives. Cross sections, isopach maps, and structure maps were developed to validate the geometry and architecture of the Citronelle Dome for building the model, and assuring that no major structural defects exist in the area. A synthetic neural network approach was used to predict porosity using the available SP and resistivity log data for the storage reservoir formations. These data are validated and applied to extrapolate porosity data over the study area wells, and to interpolate permeability amongst these data points. Geostatistical assessments were conducted over the study area. In addition to geologic characterization of the region, a suite of core analyses was conducted to construct a depositional model and constrain caprock integrity. Petrographic assessment of core was conducted by OSU and analyzed to build a depositional framework for the region and provide modern day analogues. Stability of the caprock over several test parameters was conducted by UAB to yield comprehensive measurements on long term stability of caprocks. The detailed geologic model of the full earth volume from surface thru the Donovan oil reservoir is incorporated into a state-of-the-art reservoir simulation conducted by the University of Alabama at Birmingham (UAB) to explore optimization of CO 2 injection and storage under different characterizations of reservoir flow properties. The application of a scaled up geologic modeling and reservoir simulation provides a proof of concept for the large scale volumetric modeling of CO 2 injection and storage the subsurface.« less

Regional geology subprogram: Geological interpretation of ERTS imagery of the occidental region of Bolivia

NASA Technical Reports Server (NTRS)

Brockmann, C. E. (Principal Investigator); Ayllon, R. B.

1973-01-01

The author has identified the following significant results. Using ERTS-1 imagery, it is possible to delimit great lithological units, folds, lineaments, faults, and in lesser degree unconformities. In the morphological aspect, the images show clearly the relief necessary for geological interpretation. The ERTS-1 images are important for the preparation of the geological and tectonic map of Bolivia, on a 1:1 million scale, if conventional methods of work are used as a base.

Geologic Reconnaissance and Lithologic Identification by Remote Sensing

DTIC Science & Technology

remote sensing in geologic reconnaissance for purposes of tunnel site selection was studied further and a test case was undertaken to evaluate this geological application. Airborne multispectral scanning (MSS) data were obtained in May, 1972, over a region between Spearfish and Rapid City, South Dakota. With major effort directed toward the analysis of these data, the following geologic features were discriminated: (1) exposed rock areas, (2) five separate rock groups, (3) large-scale structures. This discrimination was accomplished by ratioing multispectral channels.

Geology and religion - historical perspective and current problems

NASA Astrophysics Data System (ADS)

Kölbl-Ebert, Martina

2010-05-01

Today, when referring to the relationship between geology and religion, people usually at once think of Christian (and other) fundamentalists and their chronic palaeontological illiteracy leading to Creationism, to Intelligent Design, and a distrust of science in general among them most prominently geology, palaeontology and evolutionary biology. Thus the relationship of geology and religion is usually considered to be under strain. In former times things used to be quite different, and for most of human history the observation of geological phenomena and the acquisition of geological expertise was intimately connected with religious ideas. The Judeo-Christian sense of a finite Earth history prepared the ground for accepting the Earth's different strata as testimony to the development of our globe through time. It was this religious, theological framework, from which the early geology started to evolve. However, with increasing observations there was a growing mismatch between what was expected according to ancient, scriptural authorities and the actual data. The release of geology from religious connotations or associations was a development closely connected with the Enlightenment, when geology and religion started to drift apart not with a violent rupture but in a subtle and sometimes circuitous manner. However, outside the group of people with geological expertise, not all was smooth and peaceful, and some conservative clergymen as well as laypersons were rather shocked by the new ideas that came with geology: the immensity of the timescale, a dynamic Earth, not just a ruin shaped by the Deluge, and a dynamic biology too with the Darwinian theory of evolution, which was founded in part on palaeontological evidence and the assumption of a long geological time scale. Nevertheless and interestingly the Creationism we face today is a rather recent phenomenon influenced by a number of motives, most of them philosophical and theological in nature. And so, the current debate, if there has to be one, should not be about geology versus theology but about enlightenment versus fundamentalism. It is important that geologists should be aware that many theologians are just as appalled by the recent rise of Christian fundamentalism as they are. Probably the best remedy is to engage in dialogue with those many open-minded philosophers and theologians rather than frighten them off with a militant atheist stance, bearing in mind that dialogue requires first of all respect for the intellectual achievements of the other but also a common language to avoid misunderstandings. Two seemingly trivial words, "chance" and "design", often seem to be the core of such misunderstandings. While for a palaeontologist or biologist, it is quite possible to talk about chance and design within an evolutionary framework, e.g. undirected mutations and natural selection leading to the body-plan of certain organisms, i.e. chance and necessity leading to design, these two terms exclude each other for most theologians. "Design" for them is synonymous to "purpose", while a chance event in theology is per definition without sense and purpose. Whenever we as scientists talk of "chance", a theologian suspects that we explicitly exclude god, while we are convinced that we have not made any statement about god at all.

Are seismic waiting time distributions universal?

NASA Astrophysics Data System (ADS)

Davidsen, Jörn; Goltz, Christian

2004-11-01

We show that seismic waiting time distributions in California and Iceland have many features in common as, for example, a power-law decay with exponent α ~ 1.1 for intermediate and with exponent γ ~ 0.6 for short waiting times. While the transition point between these two regimes scales proportionally with the size of the considered area, the full distribution is not universal and depends in a non-trivial way on the geological area under consideration and its size. This is due to the spatial distribution of epicenters which does not form a simple mono-fractal. Yet, the dependence of the waiting time distributions on the threshold magnitude seems to be universal.

Quaternary geologic map of the Wolf Point 1° × 2° quadrangle, Montana and North Dakota

USGS Publications Warehouse

Fullerton, David S.; Colton, Roger B.; Bush, Charles A.

2016-09-08

The Wolf Point quadrangle encompasses approximately 16,084 km2 (6,210 mi2). The northern boundary is the Montana/Saskatchewan (U.S.-Canada) boundary. The quadrangle is in the Northern Plains physiographic province and it includes the Peerless Plateau and Flaxville Plain. The primary river is the Missouri River.The map units are surficial deposits and materials, not landforms. Deposits that comprise some constructional landforms (for example, ground-moraine deposits, end-moraine deposits, and stagnation-moraine deposits, all composed of till) are distinguished for purposes of reconstruction of glacial history. Surficial deposits and materials are assigned to 23 map units on the basis of genesis, age, lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized in pedology or agronomy.  Rather, it is a generalized map of soils recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed.  Glaciotectonic (ice-thrust) structures and deposits are mapped separately, represented by a symbol. The surficial deposits are glacial, ice-contact, glaciofluvial, alluvial, lacustrine, eolian, colluvial, and mass-movement deposits.Till of late Wisconsin age is represented by three map units. Till of Illinoian age also is mapped.  Till deposited during pre-Illinoian glaciations is not mapped, but is widespread in the subsurface.  Linear ice-molded landforms (primarily drumlins), shown by symbol, indicate directions of ice flow during late Wisconsin and Illinoian glaciations. The Quaternary geologic map of the Wolf Point quadrangle, northeastern Montana and North Dakota, was prepared to provide a database for compilation of a Quaternary geologic map of the Regina 4° × 6° quadrangle, United States and Canada, at scale 1:1,000,000, for the U.S. Geological Survey Quaternary Geologic Atlas of the United States map series.  This map was compiled from data from many sources, at several different map scales.  That information was generalized and simplified, and then transferred to a base map at 1:250,000 scale to serve as the base for final reduction to 1:1,000,000, the nominal reading scale of maps in the Quaternary Geologic Atlas of the United States map series.  This map is the generalized and simplified 1:250,000 scale compilation.  Letter symbols for the map units are those used for the same units in the Quaternary Geologic Atlas of the United States map series. The map summarizes new, and selected published and unpublished, geologic information for public use and for use by Federal, State, and local governmental agencies for land use planning, including assessment of natural resources, natural hazards, recreation potential, and land use management.  It also is a base from which a variety of maps relating to earth surface processes and Quaternary geologic history can be derived.

Investigation of Non-Linear Dynamics of the Rock Massive,Using Seismological Catalogue data and Induction Electromagnetic Monitoring Data in a Rock Burst Mine.

NASA Astrophysics Data System (ADS)

Hachay, O. A.; Khachay, O. Y.; Klimko, V. K.; Shipeev, O. V.

2012-04-01

Geological medium is an open dynamical system, which is influenced on different scales by natural and man-made impacts, which change the medium state and lead as a result to a complicated many ranked hierarchic evolution. That is the subject of geo synergetics. Paradigm of physical mesomechanics, which was advanced by academician Panin V.E. and his scientific school, which includes the synergetic approach is a constructive method for research and changing the state of heterogenic materials [1]. That result had been obtained on specimens of different materials. In our results of research of no stationary geological medium in a frame of natural experiments in real rock massifs, which are under high man-made influence it was shown, that the state dynamics can be revealed with use synergetics in hierarchic medium. Active and passive geophysical monitoring plays a very important role for research of the state of dynamical geological systems. It can be achieved by use electromagnetic and seismic fields. Our experience of that research showed the changing of the system state reveals on the space scales and times in the parameters, which are linked with the peculiarities of the medium of the second or higher ranks [2-5]. Results of seismological and electromagnetic information showed the mutual additional information on different space-time levels of rock massive state, which are energetic influenced by explosions, used in mining technology. It is revealed a change of nonlinearity degree in time of the massive state by active influence on it. The description of massive movement in a frame of linear dynamical system does not satisfy the practical situation. The received results are of great significance because for the first time we could find the coincidences with the mathematical theory of open systems and experimental natural results with very complicated structure. On that base we developed a new processing method for the seismological information which can be used in real time for estimation of the disaster degree changing in mine massive. The work was supported by the grant RFBR 10-05-00013. 1. Panin,V.E. et all. 1995. Physical mesomechanics and computer construction of materials . Novosibirsk.: Nauka, SIFR. V.1 pp. 350. 2. Hachay, O.A. 2006. "The problem of the research of redistribution of stress and phase states of massive between high man-made influences," Mining information and analytic bulletin, 5:109-115. 3. Hachay, O.A. and Khachay, O.Yu. 2008. "Theoretical approaches for system of geophysical state control validation of geological medium by man-made influence," Mining information and analytic bulletin 1:161-169. 4. Hachay, O.A., and Khachay, O.Yu. 2009. "Results of electromagnetic and seismic monitoring of the state of rock massive by use the approach of the open dynamical systems,"presented at the EGU2009 - EGU General Assembly 2009, session: Thermo- hydro- mechanical coupling in stressed rock, 19 April 19 - 24 April 2009. 5. Hachay, O.A. "Synergetic events in geological medium and nonlinear features of wave propagation," presented at the EGU2009 - EGU General Assembly 2009, session: Solid Earth geocomplexity: surface processes, morphology and natural resources over wide ranges of scale, 19 April 19 - 24 April 2009.

Sedimentary Geology Context and Challenges for Cyberinfrastructure Data Management

NASA Astrophysics Data System (ADS)

Chan, M. A.; Budd, D. A.

2014-12-01

A cyberinfrastructure data management system for sedimentary geology is crucial to multiple facets of interdisciplinary Earth science research, as sedimentary systems form the deep-time framework for many geoscience communities. The breadth and depth of the sedimentary field spans research on the processes that form, shape and affect the Earth's sedimentary crust and distribute resources such as hydrocarbons, coal, and water. The sedimentary record is used by Earth scientists to explore questions such as the continental crust evolution, dynamics of Earth's past climates and oceans, evolution of the biosphere, and the human interface with Earth surface processes. Major challenges to a data management system for sedimentary geology are the volume and diversity of field, analytical, and experimental data, along with many types of physical objects. Objects include rock samples, biological specimens, cores, and photographs. Field data runs the gamut from discrete location and spatial orientation to vertical records of bed thickness, textures, color, sedimentary structures, and grain types. Ex situ information can include geochemistry, mineralogy, petrophysics, chronologic, and paleobiologic data. All data types cover multiple order-of-magnitude scales, often requiring correlation of the multiple scales with varying degrees of resolution. The stratigraphic framework needs dimensional context with locality, time, space, and depth relationships. A significant challenge is that physical objects represent discrete values at specific points, but measured stratigraphic sections are continuous. In many cases, field data is not easily quantified, and determining uncertainty can be difficult. Despite many possible hurdles, the sedimentary community is anxious to embrace geoinformatic resources that can provide better tools to integrate the many data types, create better search capabilities, and equip our communities to conduct high-impact science at unprecedented levels.

The Depositional and Erosional History of Northwestern Aeolis Mons, Gale Crater, Mars: Insights from Detailed 1:2K Geologic Mapping

NASA Astrophysics Data System (ADS)

Edgar, L. A.; Calef, F. J., III; Thomson, B. J.

2017-12-01

The Mars Science Laboratory (MSL) Curiosity rover is currently exploring the stratigraphy exposed in Aeolis Mons, the central mound of Gale crater. Gale crater has been the target of numerous remote sensing studies, aimed at understanding the origin and evolution of the mound, informally known as Mt. Sharp. A number of efforts have produced geologic maps of the mound and the MSL traverse path, in order to investigate the stratigraphic relationships between different sedimentary units. However, a scale gap exists between local mapping and stratigraphic analyses of the area explored by Curiosity and regional mapping of Aeolis Mons. As Curiosity explores the northwest flank of Aeolis Mons, there is a critical need for investigations to bridge this gap to enable rover-scale observations to be tied to orbital interpretations. This study is focused on detailed geologic mapping and stratigraphic correlations for the northwest flank of Aeolis Mons, including an area that the Curiosity rover will likely explore. The study region covers a 5.8 x 10 km area from approximately 137.27 to 137.44 °E and -4.70 to -4.82 °N. A 25 cm/pixel mosaic produced from images acquired by the High Resolution Imaging Science Experiment (HiRISE) camera provides a basemap for all mapping, and topographic information is provided by a HiRISE 1 m Digital Terrain Model. Preliminary digital geologic mapping was carried out at a scale of 1:10,000 to provide a framework for detailed geologic mapping efforts. Higher-resolution geologic mapping was then conducted at a scale of 1:2,000, and type localities were identified. As a result of newer, higher-resolution datasets that are now available and more narrowly focused mapping, we identify a number of new geologic units. Erosional remnants of some units point to a substantial erosional history. Collectively, the stratigraphy records diverse sedimentary environments and more variability in the depositional and erosional histories than previously identified. This study helps bridge the gap between previous mapping efforts and detailed rover-scale mapping, and will enable rover observations to be more closely tied to orbital interpretations across the northwest flank of Aeolis Mons.

Precomputing upscaled hydraulic conductivity for complex geological structures

NASA Astrophysics Data System (ADS)

Mariethoz, G.; Jha, S. K.; George, M.; Maheswarajah, S.; John, V.; De Re, D.; Smith, M.

2013-12-01

3D geological models are built to capture the geological heterogeneity at a fine scale. However groundwater modellers are often interested in the hydraulic conductivity (K) values at a much coarser scale to reduce the numerical burden. Upscaling is used to assign conductivity to large volumes, which necessarily causes a loss of information. Recent literature has shown that the connectivity in the channelized structures is an important feature that needs to be taken into account for accurate upscaling. In this work we study the effect of channel parameters, e.g. width, sinuosity, connectivity etc. on the upscaled values of the hydraulic conductivity and the associated uncertainty. We devise a methodology that derives correspondences between a lithological description and the equivalent hydraulic conductivity at a larger scale. The method uses multiple-point geostatistics simulations (MPS) and parameterizes the 3D structures by introducing continuous rotation and affinity parameters. Additional statistical characterization is obtained by transition probabilities and connectivity measures. Equivalent hydraulic conductivity is then estimated by solving a flow problem for the entire heterogeneous domain by applying steady state flow in horizontal and vertical directions. This is systematically performed for many random realisations of the small scale structures to enable a probability distribution for the equivalent upscaled hydraulic conductivity. This process allows deriving systematic relationships between a given depositional environment and precomputed equivalent parameters. A modeller can then exploit the prior knowledge of the depositional environment and expected geological heterogeneity to bypass the step of generating small-scale models, and directly work with upscaled values.

Geologic map of the Galaxias quadrangle (MTM 35217) of Mars

USGS Publications Warehouse

De Hon, Rene A.; Mouginis-Mark, Peter J.; Brick, Eugene E.

1999-01-01

The Galaxias region (MTM 35217) is one of a series of 1:500,000-scale science study areas on Mars sponsored by NASA's Planetary Geology and Geophysics Program. Situated near the northern limit of lava flows associated with Elysium Mons, this region includes a mixture of volcanic and nonvolcanic terrains. The region is also of interest for the fluvial systems that originate along the distal margins of the Elysium lava flows. Resolution of Viking Orbiter images used to prepare the base map ranges from 40 to 160 m/pixel. High-resolution frames (40 to 80 m/pixel) are found in the southeastern part of the map area and along the north edge of the quadrangle, but over half the quadrangle is included in medium-resolution frames (150 m/pixel). Two 8 m/pixel, very high resolution scenes are available (see fig. 1). Interpretation is complicated by variable resolution and sun angles that vary from east to west illumination on different images. Mapping methods and principles are adapted from those developed for lunar photogeologic mapping by Shoemaker and Hackman (1962), refined by Wilhelms (1972), and successfully applied by many workers to a variety of planetary surfaces. Mapping units are distinguished by topography and texture and are ranked by relative age on the basis of superposition and transection relations. Material units are assigned to time-stratigraphic systems defined by Scott and Carr (1978) and Tanaka (1986). This area is included within earlier maps that used Mariner 9 images at 1:5,000,000 scale (Elston, 1979) and globally at 1:25,000,000 scale (Scott and Carr, 1978). Regional maps based on the much higher resolutions of Viking Orbiter allowed more detailed discrimination of materials by Greeley and Guest (1987) at 1:15,000,000 scale and Tanaka and others (1992) at 1:5,000,000 scale. Some map units on this 1:500,000-scale map correspond to, or are partially equivalent to, units on the larger scale maps of Greeley and Guest (1987) and Tanaka and others (1992). Established terminology is used where feasible, but the scale of this map requires that some new units be introduced and that some previous terminology be redefined. Photogeologic methods are limited; therefore, more than one geologic explanation is given for some material units that do not readily lend themselves to an unequivocal interpretation.

Geologic Mapping Investigations of Alba Mons, Mars

NASA Astrophysics Data System (ADS)

Crown, D. A.; Berman, D. C.; Scheidt, S. P.; Hauber, E.

2018-06-01

Geologic mapping of the summit region and western flank of Alba Mons at 1:1M-scale is revealing sequences of volcanic, tectonic, impact, and degradation processes that have formed and modified the northernmost of the Tharsis volcanoes.

Publications - RI 2001-1C | Alaska Division of Geological & Geophysical

Science.gov Websites

map of the Chulitna region, southcentral Alaska, scale 1:63,360 (7.5 M) Digital Geospatial Data Digital Geospatial Data Chulitna region surficial geology Data File Format File Size Info Download

Wetlands for Wastewater: a Visual Approach to Microbial Dynamics

NASA Astrophysics Data System (ADS)

Joubert, L.; Wolfaardt, G.; Du Plessis, K.

2007-12-01

The complex character of distillery wastewater comprises high concentrations of sugars, lignins, hemicelluloses, dextrans, resins, polyphenols and organic acids which are recalcitrant to biodegradation. Microorganisms play a key role in the production and degradation of organic matter, environmental pollutants, and cycling of nutrients and metals. Due to their short life cycles microbes respond rapidly to external nutrient loading, with major consequences for the stability of biological systems. We evaluated the feasibility of wetlands to treat winery and distillery effluents in experimental systems based on constructed wetlands, including down-scaled on-site distillery wetlands, small-scale controlled greenhouse systems, and bench-scale mesocosms. Chemical, visual and molecular fingerprinting (t-RFLP) techniques were applied to study the dynamics of planktonic and attached (biofilm) communities at various points in wetlands of different size, retention time and geological substrate, and under influence of shock nutrient loadings. Variable- Pressure Scanning Electron Microscopy (VP-SEM) was applied to visualize microbial colonization, morphotype diversity and distribution, and 3D biofilm architecture. Cross-taxon and predator-prey interactions were markedly influenced by organic loading, while the presence of algae affected microbial community composition and biofilm structure. COD removal varied with geological substrate, and was positively correlated with retention time in gravel wetlands. Planktonic and biofilm communities varied markedly in different regions of the wetland and over time, as indicated by whole-community t-RFLP and VP-SEM. An integrative visual approach to community dynamics enhanced data retrieval not afforded by molecular techniques alone. The high microbial diversity along spatial and temporal gradients, and responsiveness to the physico-chemical environment, suggest that microbial communities maintain metabolic function by modifying species composition in response to fluctuations in their environment. It seems apparent that microbial community plasticity may indeed be the distinguishing characteristic of a successful wetland system.

Generalized geologic map of bedrock lithologies and surficial deposits in the Great Smoky Mountains National Park region, Tennessee and North Carolina

USGS Publications Warehouse

Southworth, Scott; Schultz, Art; Denenny, Danielle

2005-01-01

The geology of the Great Smoky Mountain National Park (GSMNP) region of Tennessee and North Carolina was studied from 1993 to 2003 as part of a cooperative investigation with the National Park Service (NPS). This work has been compiled as a 1:100,000-scale map derived from mapping done at 1:24,000 and 1:62,500 scale. The geologic data are intended to support cooperative investigations with NPS, the development of a new soil map by the Natural Resources Conservation Service, and the All Taxa Biodiversity Inventory (http://www.discoverlifeinamerica.org/). At the request of NPS, we mapped areas previously not visited, revised the geology where stratigraphic and structural problems existed, and developed a map database for use in interdisciplinary research, land management, and interpretive programs for park visitors.

Geological-structural interpretation using products of remote sensing in the region of Carrancas, Minas Gerais, Brazil

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Dossantos, A. R.; Dosanjos, C. E.; Barbosa, M. P.; Veneziani, P.

1982-01-01

The efficiency of some criteria developed for the utilization of small scale and low resolution remote sensing products to map geological and structural features was demonstrated. Those criteria were adapted from the Logical Method of Photointerpretation which consists of textural qualitative analysis of landforms and drainage net patterns. LANDSAT images of channel 5 and 7, 4 LANDSAT-RBV scenes, and 1 radar mosiac were utilized. The region of study is characterized by supracrustal metassediments (quartzites and micaschist) folded according to a "zig-zag" pattern and gnaissic basement. Lithological-structural definition was considered outstanding when compared to data acquired during field work, bibliographic data and geologic maps acquired in larger scales.

How do we know about Earth's history? Constructing the story of Earth's geologic history by collecting and interpreting evidence based scenarios.

NASA Astrophysics Data System (ADS)

Ruthford, Steven; DeBari, Susan; Linneman, Scott; Boriss, Miguel; Chesbrough, John; Holmes, Randall; Thibault, Allison

2013-04-01

Beginning in 2003, faculty from Western Washington University, Skagit Valley Community College, local public school teachers, and area tribal college members created an innovative, inquiry based undergraduate geology curriculum. The curriculum, titled "Energy and Matter in Earth's Systems," was supported through various grants and partnerships, including Math and Science Partnership and Noyce Teacher Scholarship grants from the National Science Foundation. During 2011, the authors wrote a geologic time unit for the curriculum. The unit is titled, "How Do We Know About Earth's History?" and has students actively investigate the concepts related to geologic time and methods for determining age. Starting with reflection and assessment of personal misconceptions called "Initial Ideas," students organize a series of events into a timeline. The unit then focuses on the concepts of relative dating, biostratigraphy, and historical attempts at absolute dating, including uniformitarianism, catastrophism, Halley and Joly's Salinity hypothesis, and Kelvin's Heat Loss model. With limited lecture and text, students then dive into current understandings of the age of the Earth, which include radioactive decay rates and radiometric dating. Finally, using their newfound understanding, students investigate a number of real world scenarios and create a timeline of events related to the geologic history of the Earth. The unit concludes with activities that reinforce the Earth's absolute age and direct students to summarize what they have learned by reorganizing the timeline from the "Initial Ideas" and sharing with the class. This presentation will include the lesson materials and findings from one activity titled, "The Earth's Story." The activity is located midway through the unit and begins with reflection on the question, "What are the major events in the Earth's history and when did they happen?" Students are directed to revisit the timeline of events from the "Initial Ideas" activity at the beginning of the unit. After the review and reflection, students collect and interpret six evidence based scenarios dealing with the absolute ages of various rocks, including moon and meteorite samples, microfossil data, banded iron formations, plant and animal fossils, tectonic movement, extinction events, and human migration. The scenarios are dated and allow students to have a more complete view of geologic time. Using this more complete view, students are prompted to revisit and reorganize the timeline from the "Initial Ideas." By the end of the lesson, students will demonstrate a more complete understanding of the age of the Earth, the geologic time scale, and the role of biotic factors in Earth's systems.

Charles Lyell and scientific thinking in geology

NASA Astrophysics Data System (ADS)

Virgili, Carmina

2007-07-01

Charles Lyell (1797-1875) was born at Kinnordy, Scotland. His father, an amateur botanist, and his grandfather, a navigator, gave him very soon a taste for the observation of the Nature. He went to the Oxford University to study classical literature, but he also followed the geological course of William Buckland. After having been employed as jurist for some years, in 1827 he decided on a career of geologist and held the chair of geology of the King's College of London, from 1831 on. He was a contemporary of Cuvier, Darwin, von Humboldt, Hutton, Lavoisier, and was elected 'membre correspondant' of the 'Académie des sciences, France', in January 1862. Charles Lyell is one of the eminent geologists who initiated the scientific thinking in geology, in which his famous volumes of the Principles of Geology were taken as the authority. These reference volumes are based on multiple observations and field works collected during numerous fieldtrips in western Europe (principally Spain, France, and Italy) and North America. To his name are attached, among others: ( i) the concept of uniformitarism (or actualism), which was opposed to the famous catastrophism, in vogue at that time, and which may be summarized by the expression "The present is the key to the past"; ( ii) the division of the Tertiary in three series denominated Eocene, Miocene, and Pliocene, due to the study of the age of strata by fossil faunas; ( iii) the theory according to which the orogenesis of a mountain chain, as the Pyrenees, results from different pulsations on very long time scales and was not induced by a unique pulsation during a short and intense period. The uniformity of the laws of Nature is undeniably a principle Charles Lyell was the first to state clearly and to apply to the study of the whole Earth's crust, which opened a new era in geology.

The past is the key to the future

USGS Publications Warehouse

Doe, B.R.

1983-01-01

A new major frontier of geological research, which was initiated in the 1970's, involves predicting future geologic trends or events through study of the present and past, rather than trying to understand the past, often using what one knows about the present. Like most scientific frontiers, this one began from practical considerations-environmental concerns. The lack of formal recognition of this frontier results from fragmentation among many Federal agencies and highly focused mission-oriented programs (e.g., earthquake prediction, CO2, nuclear-energy safety, etc.). Most programs aim to predict only the next 50-100 years, but much longer periods of the past need to be studied to do this. Nuclear-waste disposal has sometimes been considered in terms of the next million years, a period of time permitting significant and broad geologic changes. Decreasing public interest in environmental concerns relegates many questions from the realm of applied research back to that of basic research. Most of these questions are so fascinating, however, that the frontier is still worth pursuing. Such questions include whether a phenomenon will or will not take place and the rates at which it can develop (e.g., how fast do rifts form, how fast can a caldera event begin, and how quickly can a glacial maximum arrive?). Common elements of all studies include the historic record, trends in the Quaternary, analogues in various periods of the geologic time scale, and allowance for phenomena never experienced before. Other examples of studies include the Cretaceous as a period of a climatic extreme, an especially interesting time period; establishing the amount of paleocloudiness, a particularly challenging and important research area; acid rain as a possible new phenomenon. Geochemistry has much to contribute to this frontier science. ?? 1983.

Proxemy Research Grant NAG5-10263 Closeout Report

NASA Technical Reports Server (NTRS)

Stofan, Ellen R.

2002-01-01

Proxemy Research had a grant from NASA to perform science research of upwelling and volcanism on Venus. This was a 5 year Presidential Early Career Award to E. Stofan, entitled "Upwelling and volcanism: Constraints from regional studies and geologic mapping." Here we summarize the scientific progress and accomplishments of this grant. Scientific publications and abstracts of presentations are indicated in the final section. This was a very productive grant and the progress that was made is summarized. Attention is drawn to the publications, abstracts, and talks given in each year. Volcanism and tectonism are the dominant geological processes that have shaped the surface of Venus, as revealed by the Magellan data. However, the development of a global geologic history for Venus has caused considerable debate (e.g., Head and Basilevsky, 1996; Guest and Stofan, 1999). The lack of global time horizons on Venus, such as that provided by impact craters on most bodies and the fossil record on Earth, make developing global stratigraphies for Venus difficult, if not impossible, with current datasets. Before the geologic history of Venus can be determined and used as a constraint on potential lithospheric thickness variations through time, it is necessary to perform detailed stratigraphic studies on a local to regional scale. In addition, detailed studies of specific types of venusian features and terrains, such as coronae, volcanic rises, and large lava flow fields, may help to constrain the lithospheric thickness and its potential variations in time and space. This report describes progress made during the five year award under a Presidential Early Career Award for Scientists and Engineers which allows researchers freedom to explore new areas of research.

Hazardous geology zoning and influence factorsin the near-shore shallow strata and seabed surfaceof the modern Yellow River Delta, China

NASA Astrophysics Data System (ADS)

Li, P.

2016-12-01

In this study, on the basis of 3,200 km shallow stratigraphic section and sidescan sonar data of the coastal area of the Yellow River Delta, we delineated and interpreted a total of seven types of typical hazardous geologies, including the hazardous geology in the shallow strata (buried ancient channel and strata disturbance) and hazardous geology in the seabed surface strata (pit, erosive residual body, sand patch, sand wave and scour channel). We selected eight parameters representing the development scale of the hazardous geology as the zoning indexes, including the number of hazardous geology types, pit depth, height of erosive residual body, length of scour channel, area of sand patch, length of sand wave, width of the buried ancient channel and depth of strata disturbance, and implemented the grid processing of the research area to calculate the arithmetic sum of the zoning indexes of each unit grid one by one. We then adopted the clustering analysis method to divide the near-shore waters of the Yellow River Delta into five hazardous geology areas, namely the serious erosion disaster area controlled by Diaokou lobe waves, hazardous geology area of multi-disasters under the combined action of the Shenxiangou lobe river wave flow, accumulation type hazardous geology area controlled by the current estuary river, hazardous geology area of single disaster in the deep water area and potential hazardous geology area of the Chengdao Oilfield. All four of the main factors affecting the development of hazardous geology, namely the diffusion and movement of sediment flux of the Yellow River water entering the sea, seabed stability, bottom sediment type and distribution, as well as the marine hydrodynamic characteristics, show significant regional differentiation characteristics and laws. These characteristics and laws are consistent with the above-mentioned zoning results, in which the distribution, scale and genetic mechanism of hazardous geology are considered comprehensively. This indicates that the hazardous geology zoning based on the cluster analysis is a new attempt in research regarding the hazardous geology zoning of the near-shore waters of the modern Yellow River Delta and that this type of zoning has a high level of reasonability.

The High Resolution Stereo Camera (HRSC): 10 Years of Imaging Mars

NASA Astrophysics Data System (ADS)

Jaumann, R.; Neukum, G.; Tirsch, D.; Hoffmann, H.

2014-04-01

The HRSC Experiment: Imagery is the major source for our current understanding of the geologic evolution of Mars in qualitative and quantitative terms.Imaging is required to enhance our knowledge of Mars with respect to geological processes occurring on local, regional and global scales and is an essential prerequisite for detailed surface exploration. The High Resolution Stereo Camera (HRSC) of ESA's Mars Express Mission (MEx) is designed to simultaneously map the morphology, topography, structure and geologic context of the surface of Mars as well as atmospheric phenomena [1]. The HRSC directly addresses two of the main scientific goals of the Mars Express mission: (1) High-resolution three-dimensional photogeologic surface exploration and (2) the investigation of surface-atmosphere interactions over time; and significantly supports: (3) the study of atmospheric phenomena by multi-angle coverage and limb sounding as well as (4) multispectral mapping by providing high-resolution threedimensional color context information. In addition, the stereoscopic imagery will especially characterize landing sites and their geologic context [1]. The HRSC surface resolution and the digital terrain models bridge the gap in scales between highest ground resolution images (e.g., HiRISE) and global coverage observations (e.g., Viking). This is also the case with respect to DTMs (e.g., MOLA and local high-resolution DTMs). HRSC is also used as cartographic basis to correlate between panchromatic and multispectral stereo data. The unique multi-angle imaging technique of the HRSC supports its stereo capability by providing not only a stereo triplet but also a stereo quintuplet, making the photogrammetric processing very robust [1, 3]. The capabilities for three dimensional orbital reconnaissance of the Martian surface are ideally met by HRSC making this camera unique in the international Mars exploration effort.

Analogues to features and processes of a high-level radioactive waste repository proposed for Yucca Mountain, Nevada

USGS Publications Warehouse

Simmons, Ardyth M.; Stuckless, John S.; with a Foreword by Abraham Van Luik, U.S. Department of Energy

2010-01-01

Natural analogues are defined for this report as naturally occurring or anthropogenic systems in which processes similar to those expected to occur in a nuclear waste repository are thought to have taken place over time periods of decades to millennia and on spatial scales as much as tens of kilometers. Analogues provide an important temporal and spatial dimension that cannot be tested by laboratory or field-scale experiments. Analogues provide one of the multiple lines of evidence intended to increase confidence in the safe geologic disposal of high-level radioactive waste. Although the work in this report was completed specifically for Yucca Mountain, Nevada, as the proposed geologic repository for high-level radioactive waste under the U.S. Nuclear Waste Policy Act, the applicability of the science, analyses, and interpretations is not limited to a specific site. Natural and anthropogenic analogues have provided and can continue to provide value in understanding features and processes of importance across a wide variety of topics in addressing the challenges of geologic isolation of radioactive waste and also as a contribution to scientific investigations unrelated to waste disposal. Isolation of radioactive waste at a mined geologic repository would be through a combination of natural features and engineered barriers. In this report we examine analogues to many of the various components of the Yucca Mountain system, including the preservation of materials in unsaturated environments, flow of water through unsaturated volcanic tuff, seepage into repository drifts, repository drift stability, stability and alteration of waste forms and components of the engineered barrier system, and transport of radionuclides through unsaturated and saturated rock zones.

What happens when catchments get excited? Exploring the link between hydrologic states and responses across spatial scales

NASA Astrophysics Data System (ADS)

Wrede, S.; Lyon, S. W.; Martinez-Carreras, N.; Pfister, L.; Uhlenbrook, S.

2010-12-01

Investigating relationships between dynamic hydrologic states and associated hydrologic responses of catchments is essential for a better understanding and conceptualization of hydrologic functioning and classification across spatial scales. Nevertheless, the question of “What happens when catchments get excited?” still remains unanswered for most catchments to date. This is especially true with regard to underlying landscape controls and how their relative importance can shift given the state of the various storages in a catchment. To help answering this question, we combined hydrometric and tracer approaches with landscape analysis in 24 nested catchments in Luxembourg, Europe with contrasting bedrock geology ranging from 0.5 to 1091 km2. In our study we discerned two major hydrological states (dry and wet) for each basin according to slope changes in double mass curves of cumulated discharge and precipitation. For each of these states the long-term (i.e. interannual) response of catchment behavior was characterized using conventional runoff signatures, such as master recession curves and average lag time between rainfall and runoff response. We found significantly different hydrologic responses for different hydrologic states of the catchments. These are typified by faster flow recessions, but longer average lag times during wet states and slower flow recessions, but shorter lag times during dry states. Dominating landscape controls on hydrological responses differed during these distinct hydrologic states and were identified as variables related to geology (percentage of impervious bedrock area) and soils (average soil depth), indicating different controls on hydrologic processes under different hydrologic states. Clustering of biweekly conductivity and silica stream water concentration data of the catchments further illustrated the dominant control of the geology on stream chemistry and revealed similar patterns during different hydrologic states. Our findings demonstrate that hydrologic response and their associated controls are closely linked to the dynamic hydrologic states of the catchments and hence should not be neglected in catchment modeling and classification approaches.

Chaotic evolution of the long-period Milankovitch cycle during the early Mesozoic: independent evidences from the Newark lacustrine sequence (North America) and the pelagic bedded chert sequence (Japan)

NASA Astrophysics Data System (ADS)

Ikeda, M.; Olsen, P. E.; Tada, R.

2012-12-01

The correlation of Earth's orbital parameters with climatic variations has been used to generate astronomically calibrated geologic time scales of high accuracy. However, because of the chaotic behavior of the solar planets, the orbital models have a large uncertainty beyond several tens of million years in the past. This chaotic behavior also causes the long-period astronomical cycles (> 0.5 Myr periodicity) to modulate their frequency and amplitude. In other words, their modulation patterns could be potential constraints for the orbital models. Here we report the first geologic constraints on the timing of frequency transition and amplitude modulation of the ~ 2 Myr long eccentricity cycles during the early Mesozoic. We examined the lake level records of the early Mesozoic Newark lacustrine sequence in North America and the biogenic silica burial rate of the pelagic bedded chert sequence in the Inuyama area, Japan, which are proven to be reflect the astronomical cycle (Olsen, 1986; Olsen and Kent, 1996; Ikeda et al., 2010). The time scales of the two sequences were orbitally calibrated with the end-Triassic mass extinction interval as the age anchor, covering ~ 30 Myr and ~ 65 Myr, respectively (Olsen et al., 2011; Ikeda et al., 2010, in prep). We find that the frequency modulation of ~ 2 Myr cycle between 2.4 Myr to 1.6 Myr cycle have occurred at least the Middle to Late Triassic. In addition, the ~ 2 Myr cycle modulate its amplitude with ~ 10 Myr periodicity with in-phase relation between the two. Similar modulation patterns of ~ 2 Myr cycles from the two independent geologic records indicate convincing evidences for the chaotic behavior of the Solar planets. Because these modulation patterns are different from the results of the orbital models by Laskar et al. (2004, 2011), our records will provide the new and challenging constraints for the orbital models in terms of chaotic behavior of Solar planets.

Geologic map and guide of the island of Oahu, Hawaii

USGS Publications Warehouse

Stearns, Harold T.

1939-01-01

This bulletin, although designated Bulletin 2, is actually the fourth of a series published by the Division of Hydrography of the Territory of Hawaii. All four of the bulletins thus far published relate to the geology and ground-water resources of the island of Oahu.1 Together they present the results obtained on this island in the program of ground-water investigation of the Territory that has been conducted in cooperation with the Geological Survey, of the United States Department of the Interior. Bulletin 5 which is in preparation will describe the progress made in developing the ground-water resources of Oahu since Bulletin 1 was issued. In Bulletin 2 is presented the detailed geologic map of Oahu that has resulted from this investigation. The base for this map is the new topographic map of Oahu prepared by the Topographic Branch of the Geological Survey. This bulletin also contains a guide to the geology along the main highways, which can be used advantageously in connection with the geologic map. For 18 years the writer has had the great privilege of working under the technical direction of Mr. 0. E. Meinzer, geologist in charge of the Division of Ground Water, U. S. Geological Survey. Nearly two decades ago Mr. Meinzer envisioned the great benefits that the people of Hawaii would derive from a thorough study of the groundwater resources of these islands. He also recognized that a full knowledge of these resources could be obtained only by a complete understanding of the geology of the islands and the processes which formed them. This bulletin is one of a series that has been made possible largely as a result of his broad vision. Credit is due Mr. W. 0 . Clark for the location of all the dikes shown on plate 2 in the headwaters of Kamananui Stream near the north end of the Koolau Range, and to Dr. C. K. Wentworth for about a dozen dikes north of Kaimuki. Messrs. 0. E. Meinzer, G. R. Mansfield, M. H. Carson, G. A. Macdonald, and S. H. Elbert kindly criticized the manuscript. Mr. Harry L. Taeuber designed the cover and with James Y. Nitta prepared the illustrations. Their work has greatly enriched this bulletin. The topographic maps of 15-minute quadrangles, on a scale of 1 to 20,000 (approximately 3 inches to the mile), were used in the field as a base for the geologic mapping. The data were then transferred to the new topographic map of Oahu, which is on a scale of 1 to 62,500. The resulting geologic map is reproduced as plate 2 (in pocket) of this report. Some of the outcrops are too small to be shown on this smaller map. Plate 2 of this report was listed as plate 2 in Bulletin 1, which was, however, published without the map because of the time required to prepare and engrave the topographic base and the geologic map. The geologic structure sections at the bottom of plate 2 were not described in Bulletin 1, but are discussed below.

To assess the value of satellite imagery in resource evaluation on a national scale. [South Africa

NASA Technical Reports Server (NTRS)

Malan, O. G. (Principal Investigator)

1973-01-01

The author has identified the following significant results. It has been shown that ERTS imagery, particularly in the form of 1:500,000 scale false color photolithographic prints, can contribute very significantly towards facilitating and accelerating (dramatically, in the case of vegetation) resource surveys and geologic mapping. Fire mapping on a national scale becomes a feasibility, numerous new geologic features, particularly lineaments, have been discovered, land use can be mapped efficiently on a regional scale and degraded areas identified. The first detailed tectonic and geomorphological maps of the Republic of South Africa will be published in the near future mainly owing to the availability of ERTS-1 imagery.

Lattice Boltzmann-Based Approaches for Pore-Scale Reactive Transport

DOE PAGES

Yoon, Hongkyu; Kang, Qinjun; Valocchi, Albert J.

2015-07-29

Here an important geoscience and environmental applications such as geologic carbon storage, environmental remediation, and unconventional oil and gas recovery are best understood in the context of reactive flow and multicomponent transport in the subsurface environment. The coupling of chemical and microbiological reactions with hydrological and mechanical processes can lead to complex behaviors across an enormous range of spatial and temporal scales. These coupled responses are also strongly influenced by the heterogeneity and anisotropy of the geologic formations. Reactive transport processes can change the pore morphology at the pore scale, thereby leading to nonlinear interactions with advective and diffusive transport,more » which can strongly influence larger-scale properties such as permeability and dispersion.« less

Beta Regio - Phoebe Regio on Venus: Geologic mapping with the Magellan data

NASA Technical Reports Server (NTRS)

Nikishin, A. M.; Borozdin, V. K.; Bobina, N. N.; Burba, G. A.

1993-01-01

The geologic maps of C1-15N283 and C1-00N283 sheets were produced (preliminary versions) with Magellan SAR images. This work was undertaken as a part of Russia's contribution into C1 geologic mapping efforts. The scale of the original maps is 1:8,000,000, and the maps are reproduced here at a reduced size.

Onshore and offshore geologic map of the Coal Oil Point area, southern California

USGS Publications Warehouse

Dartnell, Pete; Conrad, James E.; Stanley, Richard G.; Guy R. Cochrane, Guy R.

2011-01-01

Geologic maps that span the shoreline and include both onshore and offshore areas are potentially valuable tools that can lead to a more in depth understanding of coastal environments. Such maps can contribute to the understanding of shoreline change, geologic hazards, both offshore and along-shore sediment and pollutant transport. They are also useful in assessing geologic and biologic resources. Several intermediate-scale (1:100,000) geologic maps that include both onshore and offshore areas (herein called onshore-offshore geologic maps) have been produced of areas along the California coast (see Saucedo and others, 2003; Kennedy and others, 2007; Kennedy and Tan, 2008), but few large-scale (1:24,000) maps have been produced that can address local coastal issues. A cooperative project between Federal and State agencies and universities has produced an onshore-offshore geologic map at 1:24,000 scale of the Coal Oil Point area and part of the Santa Barbara Channel, southern California (fig. 1). As part of the project, the U.S. Geological Survey (USGS) and the California Geological Survey (CGS) hosted a workshop (May 2nd and 3rd, 2007) for producers and users of coastal map products (see list of participants) to develop a consensus on the content and format of onshore-offshore geologic maps (and accompanying GIS files) so that they have relevance for coastal-zone management. The USGS and CGS are working to develop coastal maps that combine geospatial information from offshore and onshore and serve as an important tool for addressing a broad range of coastal-zone management issues. The workshop was divided into sessions for presentations and discussion of bathymetry and topography, geology, and habitat products and needs of end users. During the workshop, participants reviewed existing maps and discussed their merits and shortcomings. This report addresses a number of items discussed in the workshop and details the onshore and offshore geologic map of the Coal Oil Point area. Results from this report directly address issues raised in the California Ocean Protection Act (COPA) Five Year Strategic Plan. For example, one of the guiding principles of the COPA five-year strategic plan is to 'Recognize the interconnectedness of the land and the sea, supporting sustainable uses of the coast and ensuring the health of ecosystems.' Results from this USGS report directly connect the land and sea with the creation of both a seamless onshore and offshore digital terrain model (DTM) and geologic map. One of the priority goals (and objectives) of the COPA plan is to 'monitor and map the ocean environment to provide data about conditions and trends.' Maps within this report provide land and sea geologic information for mapping and monitoring nearshore sediment processes, pollution transport, and sea-level rise and fall.

First ERTS-1 results in southeastern France: Geology, sedimentology, pollution at sea

NASA Technical Reports Server (NTRS)

Fontanel, A.; Guillemot, J.; Guy, M.

1973-01-01

Results obtained by four ERTS projects in southeastern France are summarized. With regard to geology, ERTS photos of Western Alps are very useful for tectonic interpretation because large features are clearly visible on these photographs even though they are often hidden by small complicated structures if studied on large scale documents. The 18-day repetition coverage was not obtained, and time-varying sedimentological surveys were impossible. Nevertheless, it was possible to delineate the variations of the shorelines in the Rhone Delta for a period covering the least 8,000 years. Some instances of industries discharging pollutant products at sea were detected, as well as very large anomalies of unknown origin. Some examples of coherent optical processing have been made in order to bring out tectonic features in the Alps mountains.

Forensic geoscience: applications of geology, geomorphology and geophysics to criminal investigations

NASA Astrophysics Data System (ADS)

Ruffell, Alastair; McKinley, Jennifer

2005-03-01

One hundred years ago Georg Popp became the first scientist to present in court a case where the geological makeup of soils was used to secure a criminal conviction. Subsequently there have been significant advances in the theory and practice of forensic geoscience: many of them subsequent to the seminal publication of "Forensic Geology" by Murray and Tedrow [Murray, R., Tedrow, J.C.F. 1975 (republished 1986). Forensic Geology: Earth Sciences and Criminal Investigation. Rutgers University Press, New York, 240 pp.]. Our review places historical development in the modern context of how the allied disciplines of geology (mineralogy, sedimentology, microscopy), geophysics, soil science, microbiology, anthropology and geomorphology have been used as tool to aid forensic (domestic, serious, terrorist and international) crime investigations. The latter half of this paper uses the concept of scales of investigation, from large-scale landforms through to microscopic particles as a method of categorising the large number of geoscience applications to criminal investigation. Forensic geoscience has traditionally used established non-forensic techniques: 100 years after Popp's seminal work, research into forensic geoscience is beginning to lead, as opposed to follow other scientific disciplines.

Surficial geologic map of the Gates of the Arctic National Park and Preserve, Alaska

USGS Publications Warehouse

Hamilton, Thomas D.; Labay, Keith A.

2011-01-01

The surfical geologic map incorporates parts of ten surficial geologic maps previously published at 1:250,000 scale. In addition, a small part of the buffer zone mapped in the southwest corner of the map area was compiled from unpublished surficial geologic mapping of the Shungnak 1:250,000-scale quadrangle. Each of those individual maps was developed from (1) aerial and surface observations of morphology and composition of unconsolidated deposits, (2) tracing the distribution and interrelation of terraces, abandoned meltwater channels, moraines, abandoned lake beds, and other landforms, (3) stratigraphic study of exposures along lake shores and river bluffs, (4) examination of sediments and soil profiles in auger borings and test pits, and exposed in roadcuts and placer workings, and (5) analysis of previously published geologic maps and reports. The map units used for those maps and employed in the present compilation are defined on the basis of their physical character, genesis, and age. Relative and absolute ages of the map units were determined from their geographic locations and from their stratigraphic positions and radiocarbon ages.

Preliminary Modelling of the Effect of Impurity in CO2 Streams on the Storage Capacity and the Plume Migration in Pohang Basin, Korea

NASA Astrophysics Data System (ADS)

Park, Yongchan; Choi, Byoungyoung; Shinn, Youngjae

2015-04-01

Captured CO2 streams contain various levels of impurities which vary depending on the combustion technology and CO2 sources such as a power plant and iron and steel production processes. Common impurities or contaminants are non-condensable gases like nitrogen, oxygen and hydrogen, and are also air pollutants like sulphur and nitrogen oxides. Specifically for geological storage, the non-condensable gases in CO2 streams are not favourable because they can decrease density of the injected CO2 stream and can affect buoyancy of the plume. However, separation of these impurities to obtain the CO2 purity higher than 99% would greatly increase the cost of capture. In 2010, the Korean Government announced a national framework to develop CCS, with the aim of developing two large scale integrated CCS projects by 2020. In order to achieve this goal, a small scale injection project into Pohang basin near shoreline has begun which is seeking the connection with a capture project, especially at a steel company. Any onshore sites that are suitable for the geological storage are not identified by this time so we turned to the shallow offshore Pohang basin where is close to a large-scale CO2 source. Currently, detailed site surveys are being undertaken and the collected data were used to establish a geological model of the basin. In this study, we performed preliminary modelling study on the effect of impurities on the geological storage using the geological model. Using a potential compositions of impurities in CO2 streams from the steel company, we firstly calculated density and viscosity of CO2 streams as a function of various pressure and temperature conditions with CMG-WINPROP and then investigated the effect of the non-condensable gases on storage capacity, injectivity and plume migrations with CMG-GEM. Further simulations to evaluate the areal and vertical sweep efficiencies by impurities were perform in a 2D vertical cross section as well as in a 3D simulation grid. Also, pressure increases caused by the impurities and the partitioning between CO2 and other non-condensable gases were explored. In addition, the possibility of using these contaminants as a tracer were examined.

Flash-Flood hydrological simulations at regional scale. Scale signature on road flooding vulnerability

NASA Astrophysics Data System (ADS)

Anquetin, Sandrine; Vannier, Olivier; Ollagnier, Mélody; Braud, Isabelle

2015-04-01

This work contributes to the evaluation of the dynamics of the human exposure during flash-flood events in the Mediterranean region. Understanding why and how the commuters modify their daily mobility in the Cévennes - Vivarais area (France) is the long-term objective of the study. To reach this objective, the methodology relies on three steps: i) evaluation of daily travel patterns, ii) reconstitution of road flooding events in the region based on hydrological simulation at regional scale in order to capture the time evolution and the intensity of flood and iii) identification of the daily fluctuation of the exposition according to road flooding scenarios and the time evolution of mobility patterns. This work deals with the second step. To do that, the physically based and non-calibrated hydrological model CVN (Vannier, 2013) is implemented to retrieve the hydrological signature of past flash-flood events in Southern France. Four past events are analyzed (September 2002; September 2005 (split in 2 different events); October 2008). Since the regional scale is investigated, the scales of the studied catchments range from few km2 to few hundreds of km2 where many catchments are ungauged. The evaluation is based on a multi-scale approach using complementary observations coming from post-flood experiments (for small and/or ungaugged catchments) and operational hydrological network (for larger catchments). The scales of risk (time and location of the road flooding) are also compared to observed data of road cuts. The discussion aims at improving our understanding on the hydrological processes associated with road flooding vulnerability. We specifically analyze runoff coefficient and the ratio between surface and groundwater flows at regional scale. The results show that on the overall, the three regional simulations provide good scores for the probability of detection and false alarms concerning road flooding (1600 points are analyzed for the whole region). Our evaluation procedure provides new insights on the active hydrological processes at small scales (catchments area < 10 km²) since these small scales, distributed over the whole region, are analyzed through road cuts data and post-flood field investigations. As shown in Vannier (2013), the signature of the altered geological layer is significant on the simulated discharges. For catchments under schisty geology, the simulated discharge, whatever the catchment size, is usually overestimated. Vannier, O, 2013, Apport de la modélisation hydrologique régionale à la compréhension des processus de crue en zone méditerranéenne, PhD-Thesis (in French), Grenoble University.

How Darcy's equation is linked to the linear reservoir at catchment scale

NASA Astrophysics Data System (ADS)

Savenije, Hubert H. G.

2017-04-01

In groundwater hydrology two simple linear equations exist that describe the relation between groundwater flow and the gradient that drives it: Darcy's equation and the linear reservoir. Both equations are empirical at heart: Darcy's equation at the laboratory scale and the linear reservoir at the watershed scale. Although at first sight they show similarity, without having detailed knowledge of the structure of the underlying aquifers it is not trivial to upscale Darcy's equation to the watershed scale. In this paper, a relatively simple connection is provided between the two, based on the assumption that the groundwater system is organized by an efficient drainage network, a mostly invisible pattern that has evolved over geological time scales. This drainage network provides equally distributed resistance to flow along the streamlines that connect the active groundwater body to the stream, much like a leaf is organized to provide all stomata access to moisture at equal resistance.

Coral adaptation and acclimatization: A most ingenious paradox

USGS Publications Warehouse

Buddemeier, R.W.; Smith, S.V.

1999-01-01

SYNOPSIS. Reef corals and the communities they form evidently possess effective mechanisms of adaptation and acclimation that have ensured their survival and recurrence over geologic time. Current reef degradation suggests that these mechanisms are being taxed beyond their limits; understanding of the problem is hampered by serious inadequacies in our understanding of physiological stress responses, the range and implications of reproductive strategies, and the mechanisms of calcification and algal symbiosis. Reef community and population responses to environmental change appear substantially different on different time scales, and a combination of short-term perspectives and definitional confusion complicates interpretation and prediction of reef responses. Calcium carbonate saturation state is now recognized as a potentially important control of reef calcification, which means that rising atmospheric CO, represents a direct threat to reef ecosystems on a global scale.

Ultra-Long Time Dynamics of Contaminant Plume Mixing Induced by Transient Forcing Factors in Geologic Formations

NASA Astrophysics Data System (ADS)

Rajabi, F.; Battiato, I.

2016-12-01

Long term predictions of the impact of anthropogenic stressors on the environment is essential to reduce the risks associated with processes such as CO2 sequestration and nuclear waste storage in the subsurface. On the other hand, transient forcing factors (e.g. time-varying injection or pumping rate) with evolving heterogeneity of time scales spanning from days to years can influence transport phenomena at the pore scale. A comprehensive spatio-temporal prediction of reactive transport in porous media under time-dependent forcing factors for thousands of years requires the formulation of continuum scale models for time-averages. Yet, as every macroscopic model, time-averaged models can loose predictivity and accuracy when certain conditions are violated. This is true whenever lack of temporal and spatial scale separation occurs and it makes the continuum scale equation a poor assumption for the processes at the pore scale. In this work, we consider mass transport of a dissolved species undergoing a heterogeneous reaction and subject to time-varying boundary conditions in a periodic porous medium. By means of homogenization method and asymptotic expansion technique, we derive a macro-time continuum-scale equation as well as expressions for its effective properties. Our analysis demonstrates that the dynamics at the macro-scale is strongly influenced by the interplay between signal frequency at the boundary and transport processes at the pore level. In addition, we provide the conditions under which the space-time averaged equations accurately describe pore-scale processes. To validate our theoretical predictions, we consider a thin fracture with reacting walls and transient boundary conditions at the inlet. Our analysis shows a good agreement between numerical simulations and theoretical predictions. Furthermore, our numerical experiments show that mixing patterns of the contaminant plumes at the pore level strongly depend on the signal frequency.

Ganymede’s stratigraphy and crater distributions in Voyager and Galileo SSI images: results from the anti-jovian hemisphere

NASA Astrophysics Data System (ADS)

Wagner, Roland Josef; Schmedemann, Nico; Stephan, Katrin; Werner, Stephanie; Ivanov, Boris A.; Roatsch, Thomas; Jaumann, Ralf; Palumbo, Pasquale

2017-10-01

Crater size distributions are a valuable tool in planetary stratigraphy to derive the sequence of geologic events. In this study, we extend our previous work [1] in Ganymede’s sub-jovian hemisphere to the anti-jovian hemisphere. For geologic mapping, the map by [2] is used as a reference. Our study provides groundwork for the upcoming imaging by the JANUS camera aboard ESA’s JUICE mission [3]. Voyager-2 images are reprocessed using a map scale of 700 m/pxl achieved for parts of the anti-jovian hemisphere. To obtain relative ages from crater frequencies, we apply an updated crater scaling law for cratering into icy targets in order to derive a crater production function for Ganymede [1]. Also, we adopt the Poisson timing analysis method discussed and implemented recently [4] to obtain relative (and absolute model) ages. Results are compared to those from the sub-jovian hemisphere [1] as well as to support and/or refine the global stratigraphic system by [2]. Further emphasis is placed on local target areas in the anti-jovian hemisphere imaged by Galileo SSI at regional map scales of 100 to 300 m/pxl in order to study local geologic effects and processes. These areas incorporate (1) dark and (2) light tectonized materials, and (3) impact crater materials including an area with numerous secondaries from ray crater Osiris. References: [1] Wagner R. et al. (2014), DPS meeting #46, abstract 418.09. [2] Collins G. et al. (2013), U.S.G.S. Sci. Inv. Map 3237. [3] Della Corte V. et al. (2014), Proc. SPIE 9143, doi:10.1117/12.2056353. [4] Michael G. et al. (2016), Icarus 277, 279-285.

Quaternary Geology and Liquefaction Susceptibility, San Francisco, California 1:100,000 Quadrangle: A Digital Database

USGS Publications Warehouse

Knudsen, Keith L.; Noller, Jay S.; Sowers, Janet M.; Lettis, William R.

1997-01-01

This Open-File report is a digital geologic map database. This pamphlet serves to introduce and describe the digital data. There are no paper maps included in the Open-File report. The report does include, however, PostScript plot files containing the images of the geologic map sheets with explanations, as well as the accompanying text describing the geology of the area. For those interested in a paper plot of information contained in the database or in obtaining the PostScript plot files, please see the section entitled 'For Those Who Aren't Familiar With Digital Geologic Map Databases' below. This digital map database, compiled from previously unpublished data, and new mapping by the authors, represents the general distribution of surficial deposits in the San Francisco bay region. Together with the accompanying text file (sf_geo.txt or sf_geo.pdf), it provides current information on Quaternary geology and liquefaction susceptibility of the San Francisco, California, 1:100,000 quadrangle. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:100,000 or smaller. The content and character of the database, as well as three methods of obtaining the database, are described below.

Summary of space imagery studies in Utah and Nevada. [using LANDSAT 1, EREP, and Skylab imagery

NASA Technical Reports Server (NTRS)

Jensen, M. L.; Laylander, P.

1975-01-01

LANDSAT-1, Skylab, and RB-57 imagery acquired within days of each other of the San Rafael swell enabled geological mapping of individual formations of the southern portion of this broad anticlinal feature in eastern Utah. Mapping at a scale of 1/250,000 on an enhanced and enlarged S-190B image resulted in a geological map showing correlative mappable features that are indicated on the geological map of Utah at the same scale. An enhanced enlargement of an S-190B color image at a scale of 1/19,200 of the Bingham Porphyry Copper deposit allowed comparison of a geological map of the area with the space imagery map as fair for the intrusion boundaries and total lack of quality for mapping the sediments. Hydrothermal alteration is only slightly evident on space imagery at Bingham but in the Tintic mining district and the volcanic piles of the Keg and Thomas ranges, Utah, hydrothermal alteration is readily mapped on color enlargements of S-190B (SL-3, T3-3N Tr-2). A mercury soil-gas analyzer was developed for locating hidden mineralized zones which were suggested from space imagery.

Estimating the power-law distribution of Earth electrical conductivity from low-frequency, controlled-source electromagnetic responses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beskardes, G. D.; Weiss, Chester J.; Everett, M. E.

Electromagnetic responses reflect the interaction between applied electromagnetic fields and heterogeneous geoelectrical structures. Here by quantifying the relationship between multi-scale electrical properties and the observed electromagnetic response is therefore important for meaningful geologic interpretation. Furthermore, we present here examples of near-surface electromagnetic responses whose spatial fluctuations appear on all length scales, are repeatable and fractally distributed, suggesting that the spatial fluctuations may be considered as “geologic noise”.

Estimating the power-law distribution of Earth electrical conductivity from low-frequency, controlled-source electromagnetic responses

DOE PAGES

Beskardes, G. D.; Weiss, Chester J.; Everett, M. E.

2016-11-30

Electromagnetic responses reflect the interaction between applied electromagnetic fields and heterogeneous geoelectrical structures. Here by quantifying the relationship between multi-scale electrical properties and the observed electromagnetic response is therefore important for meaningful geologic interpretation. Furthermore, we present here examples of near-surface electromagnetic responses whose spatial fluctuations appear on all length scales, are repeatable and fractally distributed, suggesting that the spatial fluctuations may be considered as “geologic noise”.

Global Analysis of the Shallow Geology of Large-Scale Ocean Slopes.

DTIC Science & Technology

1983-05-01

nannoplankton. Ben- thonic forams are common in lesser amounts and pteropods may occur in warm climates at depths less than 3000 m. Siliceous...Foraminifera and nannoplankton dominate. In warm waters, carbo- nate reefs may grow in shallow depths on the tops of subsiding volcanoes (Menard...Paleozoic E Eocene A A Horizon O Oligocene Where two labels ore hyphenated (ie. M-E), the time boundary dates between the two ages. - Acoustic Basement

FUSION-Guided Hypothesis Development Leads to the Identification of N⁶,N⁶-Dimethyladenosine, a Marine-Derived AKT Pathway Inhibitor. | Office of Cancer Genomics

Cancer.gov

Chemicals found in nature have evolved over geological time scales to productively interact with biological molecules, and thus represent an effective resource for pharmaceutical development. Marine-derived bacteria are rich sources of chemically diverse, bioactive secondary metabolites, but harnessing this diversity for biomedical benefit is limited by challenges associated with natural product purification and determination of biochemical mechanism.

Development of a Protocol and a Screening Tool for Selection of DNAPL Source Area Remediation

DTIC Science & Technology

2012-02-01

the different remedial time frames used in the modeling case studies. • Matrix Diffusion: Modeling results demonstrated that in fractured rock ...being used for the ISCO, EISB and SEAR fractured rock numerical simulations at the field scale. Figure 2-4 presents the distribution of intrinsic...sedimentary limestone, sandstone, and shale, igneous basalts and granites, and metamorphous rock . For the modeling sites, three general geologies are

Discussion on the 3D visualizing of 1:200 000 geological map

NASA Astrophysics Data System (ADS)

Wang, Xiaopeng

2018-01-01

Using United States National Aeronautics and Space Administration Shuttle Radar Topography Mission (SRTM) terrain data as digital elevation model (DEM), overlap scanned 1:200 000 scale geological map, program using Direct 3D of Microsoft with C# computer language, the author realized the three-dimensional visualization of the standard division geological map. User can inspect the regional geology content with arbitrary angle, rotating, roaming, and can examining the strata synthetical histogram, map section and legend at any moment. This will provide an intuitionistic analyzing tool for the geological practitioner to do structural analysis with the assistant of landform, dispose field exploration route etc.

Geology of the Terra Cimmeria-Utopia Planitia Highland Lowland Transitional Zone: Final Technical Approach and Scientific Results

NASA Technical Reports Server (NTRS)

Skinner, J. A., Jr.; Tanaka, K. L.

2010-01-01

The southern Utopia highland-lowland transitional zone extends from northern Terra Cimmeria to southern Utopia Planitia and contains broad, bench-like platforms with depressions, pitted cones, tholi, and lobate flows. The locally occurring geologic units and landforms contrast other transitional regions and record a spatially partitioned geologic history. We systematically delineated and described the geologic units and landforms of the southern Utopia-Cimmeria highland-lowland transitional zone for the production of a 1:1,000,000-scale geologic map (MTMs 10237, 15237, 20237, 10242, 15242, 20242, 10247, 15247, and 20247). Herein, we present technical and scientific results of this mapping project.

Multiscale magmatic cyclicity, duration of pluton construction, and the paradoxical relationship between tectonism and plutonism in continental arcs

NASA Astrophysics Data System (ADS)

de Saint Blanquat, Michel; Horsman, Eric; Habert, Guillaume; Morgan, Sven; Vanderhaeghe, Olivier; Law, Richard; Tikoff, Basil

2011-03-01

The close relationship between crustal magmatism, an expression of heat dissipation, and tectonics, an expression of stress dissipation, leads to the question of their mutual relationships. Indeed, the low viscosity of magmas and the large viscosity contrast between magmas and surrounding rocks favor strain localization in magmas, and then possible "magmatic" initiation of structures at a wide range of scales. However, new data about 3-d pluton shape and duration of pluton construction perturb this simple geological image, and indicate some independence between magmatism and tectonics. In some cases we observe a direct genetic link and strong arguments for physical interactions between magmas and tectonics. In other cases, we observe an absence of these interactions and it is unclear how magma transfer and emplacement are related to lithospheric-plate dynamics. A simple explanation of this complexity follows directly from the pulsed, incremental assembly of plutons and its spatial and temporal characteristics. The size of each pluton is related to a magmatic pulsation at a particular time scale, and each of these coupled time/space scales is related to a specific process: in small plutons, we can observe the incremental process, the building block of plutons; in larger plutons, the incremental process is lost, and the pulsation, which consists of a cycle of injections at different timescales, must be related to the composition and thermal regime of the source region, itself driving magmatic processes (melting, segregation, and transfer) that interact with tectonic boundary conditions. The dynamics of pulsed magmatism observed in plutonic systems is then a proxy for deep lithospheric and magmatic processes. From our data and a review of published work, we find a positive corelation between volume and duration of pluton construction. The larger a pluton, the longer its construction time. Large/fast or small/slow plutons have not been identified to date. One consequence of this observation is that plutonic magmatic fluxes seem to be comparable from one geodynamic setting to another and also over various geologic time spans. A second consequence of this correlation is that small plutons, which are constructed in a geologically short length of time, commonly record little about tectonic conditions, and result only from the interference between magma dynamics and the local geologic setting. The fast rate of magma transfer in the crust (on the order of cm/s) relative to tectonic rates (on the order of cm/yr) explain why the incremental process of pluton construction is independent of - but not insensitive to - the tectonic setting. However, in large plutonic bodies, which correspond to longer duration magmatic events, regional deformation has time to interact with the growing pluton and can be recorded within the pluton-wall rock structure. Magma transfer operates at a very short timescale (comparable to volcanic timescales), which can be sustained over variable periods, depending on the fertility of the magma source region and its ability to feed the system. The fast operation of magmatic processes relative to crustal tectonic processes ensures that the former control the system from below.

The use of ERTS/LANDSAT imagery in relation to airborne remote sensing for terrain analysis in Western Queensland, Australia

NASA Technical Reports Server (NTRS)

Cole, M. M. (Principal Investigator); Owen-Jones, E. S.

1976-01-01

The author has identified the following significant results. LANDSAT 1 and 2 imagery contrast the geology of the Cloncurry-Dobbyn and the Gregory River-Mt. Isa areas very clearly. Known major structural features and lithological units are clearly displayed while, hitherto unknown lineaments were revealed. Throughout this area, similar rock types produce similar spectral signatures, e.g. quartzites produce light signatures, iron rich rocks produce dark signatures. More geological data are discernible at the 1:50,000 scale than on the 1:250,000 scale. Ore horizons may be identified at the 1:50,000 scale, particularly where they are associated with iron rich rocks. On the level plains north of Cloncurry, distinctive spectral signatures produced by the combined reflectances of plant cover, soils, and geology, distinguish different types of superficial deposits. Existing and former channels of the Cloncurry and Williams Rivers are distinguished at the 1:50,000 scale on both the LANDSAT 1 and 2 imagery. On the Cloncurry Plains, fence lines are discernible on the 1:50,000 LANDSAT 2 imagery.

Cratering time scales for the Galilean satellites

NASA Technical Reports Server (NTRS)

Shoemaker, E. M.; Wolfe, R. F.

1982-01-01

An attempt is made to estimate the present cratering rate for each Galilean satellite within the correct order of magnitude and to extend the cratering rates back into the geologic past on the basis of evidence from the earth-moon system. For collisions with long and short period comets, the magnitudes and size distributions of the comet nuclei, the distribution of their perihelion distances, and the completeness of discovery are addressed. The diameters and masses of cometary nuclei are assessed, as are crater diameters and cratering rates. The dynamical relations between long period and short period comets are discussed, and the population of Jupiter-crossing asteroids is assessed. Estimated present cratering rates on the Galilean satellites are compared and variations of cratering rate with time are considered. Finally, the consistency of derived cratering time scales with the cratering record of the icy Galilean satellites is discussed.

Optimal variable-grid finite-difference modeling for porous media

NASA Astrophysics Data System (ADS)

Liu, Xinxin; Yin, Xingyao; Li, Haishan

2014-12-01

Numerical modeling of poroelastic waves by the finite-difference (FD) method is more expensive than that of acoustic or elastic waves. To improve the accuracy and computational efficiency of seismic modeling, variable-grid FD methods have been developed. In this paper, we derived optimal staggered-grid finite difference schemes with variable grid-spacing and time-step for seismic modeling in porous media. FD operators with small grid-spacing and time-step are adopted for low-velocity or small-scale geological bodies, while FD operators with big grid-spacing and time-step are adopted for high-velocity or large-scale regions. The dispersion relations of FD schemes were derived based on the plane wave theory, then the FD coefficients were obtained using the Taylor expansion. Dispersion analysis and modeling results demonstrated that the proposed method has higher accuracy with lower computational cost for poroelastic wave simulation in heterogeneous reservoirs.

Field Geology/Processes

NASA Technical Reports Server (NTRS)

Allen, Carlton; Jakes, Petr; Jaumann, Ralf; Marshall, John; Moses, Stewart; Ryder, Graham; Saunders, Stephen; Singer, Robert

1996-01-01

The field geology/process group examined the basic operations of a terrestrial field geologist and the manner in which these operations could be transferred to a planetary lander. Four basic requirements for robotic field geology were determined: geologic content; surface vision; mobility; and manipulation. Geologic content requires a combination of orbital and descent imaging. Surface vision requirements include range, resolution, stereo, and multispectral imaging. The minimum mobility for useful field geology depends on the scale of orbital imagery. Manipulation requirements include exposing unweathered surfaces, screening samples, and bringing samples in contact with analytical instruments. To support these requirements, several advanced capabilities for future development are recommended. Capabilities include near-infrared reflectance spectroscopy, hyper-spectral imaging, multispectral microscopy, artificial intelligence in support of imaging, x ray diffraction, x ray fluorescence, and rock chipping.

U.S. Geological Survey coastal and marine geology research; recent highlights and achievements

USGS Publications Warehouse

Williams, S. Jeffress; Barnes, Peter W.; Prager, Ellen J.

2000-01-01

The USGS Coastal and Marine Geology Program has large-scale national and regional research projects that focus on environmental quality, geologic hazards, natural resources, and information transfer. This Circular highlights recent scientific findings of the program, which play a vital role in the USGS endeavor to understand human interactions with the natural environment and to determine how the fundamental geologic processes controlling the Earth work. The scientific knowledge acquired through USGS research and monitoring is critically needed by planners, government agencies, and the public. Effective communication of the results of this research will enable the USGS Coastal and Marine Geology Program to play an integral part in assisting the Nation in responding the pressing Earth science challenges of the 21st century.

Digital geologic map of the Spokane 1:100,000 quadrangle, Washington and Idaho: a digital database for the 1990 N.L. Joseph map

USGS Publications Warehouse

Johnson, Bruce R.; Derkey, Pamela D.

1998-01-01

Geologic data from the geologic map of the Spokane 1:100,000-scale quadrangle compiled by Joseph (1990) were entered into a geographic information system (GIS) as part of a larger effort to create regional digital geology for the Pacific Northwest. The map area is located in eastern Washington and extends across the state border into western Idaho (Fig. 1). This open-file report describes the methods used to convert the geologic map data into a digital format, documents the file structures, and explains how to download the digital files from the U.S. Geological Survey public access World Wide Web site on the Internet.

National Uranium Resource Evaluation. Volume 1. Summary of the geology and uranium potential of Precambrian conglomerates in southeastern Wyoming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karlstrom, K.E.; Houston, R.S.; Flurkey, A.J.

1981-02-01

A series of uranium-, thorium-, and gold-bearing conglomerates in Late Archean and Early Proterozoic metasedimentary rocks have been discovered in southern Wyoming. The mineral deposits were found by applying the time and strata bound model for the origin of uranium-bearing quartz-pebble conglomerates to favorable rock types within a geologic terrane known from prior regional mapping. No mineral deposits have been discovered that are of current (1981) economic interest, but preliminary resource estimates indicate that over 3418 tons of uranium and over 1996 tons of thorium are present in the Medicine Bow Mountains and that over 440 tons of uranium andmore » 6350 tons of thorium are present in Sierra Madre. Sampling has been inadequate to determine gold resources. High grade uranium deposits have not been detected by work to date but local beds of uranium-bearing conglomerate contain as much as 1380 ppM uranium over a thickness of 0.65 meters. This project has involved geologic mapping at scales from 1/6000 to 1/50,000 detailed sampling, and the evaluation of 48 diamond drill holes, but the area is too large to fully establish the economic potential with the present information. This first volume summarizes the geologic setting and geologic and geochemical characteristics of the uranium-bearing conglomerates. Volume 2 contains supporting geochemical data, lithologic logs from 48 drill holes in Precambrian rocks, and drill site geologic maps and cross-sections from most of the holes. Volume 3 is a geostatistical resource estimate of uranium and thorium in quartz-pebble conglomerates.« less

Carleton College Geology Department: Seventy Years of Planning for Change

NASA Astrophysics Data System (ADS)

Savina, M. E.; Davidson, C.

2003-12-01

On the back of a fire door leading to the Carleton geology lounge and classroom, students have painted a geologic time scale representing the history of the geology department from its establishment in 1933 to its present configuration. Along the way, Laurence McKinley Gould, George Gibson, Duncan Stewart VII, Leonard Wilson, Eiler Henrickson, Ed Buchwald, Shelby Boardman, Mary Savina, David Bice, Clem Shearer, Bereket Haileab, Clint Cowan, Cam Davidson, Jenn Macalady and a host of other faculty have contributed to an excellent undergraduate program. Features that have maintained the strength of the program over the years include: Outstanding support staff (Betty Bray and Tim Vick); Weekly department meetings that include discussion of department goals and pedagogy, including attention to giving students the tools to complete the major and capstone project; Regular department retreats that allow more comprehensive discussion; Encouraging different teaching styles among the faculty; A curriculum that emphasizes active learning from day one in introductory geology through the senior capstone experience; Involving students in the department, from planning field trips to hiring to TAs; Increasing student role models by having sophomore, junior and senior majors in most courses; Emphasizing the liberal arts character of geology, rather than pre-professional; Bringing alumni back to campus on a regular basis; Publishing an annual alumni newsletter and maintaining a department web site; Creating a social and intellectual space within the department for students and faculty; Making a particular effort to be welcoming and affirming to people of all colors, ethnicities, affectional orientations and gender identities;

Geologic Mapping of the Lunar South Pole, Quadrangle LQ-30: Volcanic History and Stratigraphy of Schroedinger Basin

NASA Technical Reports Server (NTRS)

Mest, S. C.; Berman, D. C.; Petro, N. E.

2009-01-01

In this study we use recent images and topographic data to map the geology and geomorphology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-4] in accordance with the Lunar Geologic Mapping Program. Mapping of LQ-30 began during Mest's postdoctoral appointment and has continued under the PG&G Program, from which funding became available in February 2009. Preliminary map-ping and analyses have been done using base materials compiled by Mest, but properly mosaicked and spatially registered base materials are being compiled by the USGS and should be received by the end of June 2009. The overall objective of this research is to constrain the geologic evolution of the lunar South Pole (LQ-30: 60deg -90deg S, 0deg - +/-180deg ) with specific emphasis on evaluation of a) the regional effects of basin formation on the structure and composition of the crust and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Constraining the geologic history of the lunar South Pole and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the vertical and lateral structure of the lunar regolith and crust, assessing the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of resources (e.g., H, Fe, Th) and their relationships with surface materials.

"Days of future passed" - climate change and carbon cycle history (Jean Baptiste Lamarck Medal Lecture)

NASA Astrophysics Data System (ADS)

Weissert, Helmut

2013-04-01

With the beginning of the fossil fuel age in the 19th century mankind has become an important geological agent on a global scale. For the first time in human history action of man has an impact on global biogeochemical cycles. Increasing CO2 concentrations will result in a perturbation of global carbon cycling coupled with climate change. Investigations of past changes in carbon cycling and in climate will improve our predictions of future climate. Increasing atmospheric CO2 concentrations will drive climate into a mode of operation, which may resemble climate conditions in the deep geological past. Pliocene climate will give insight into 400ppm world with higher global sea level than today. Doubling of pre-industrial atmospheric CO2 levels will shift the climate system into a state resembling greenhouse climate in the Early Cenozoic or even in the Cretaceous. Carbon isotope geochemistry serves as tool for tracing the pathway of the carbon cycle through geological time. Globally registered negative C-isotope anomalies in the C-isotope record are interpreted as signatures of rapid addition (103 to a few 104 years) of CO2 to the ocean-atmosphere system. Positive C-isotope excursions following negative spikes record the slow post-perturbation recovery of the biosphere at time scales of 105 to 106 years. Duration of C-cycle perturbations in earth history cannot be directly compared with rapid perturbation characterizing the Anthropocene. However, the investigation of greenhouse pulses in the geological past provides insight into different climate states, it allows to identify tipping points in past climate systems and it offers the opportunity to learn about response reactions of the biosphere to rapid changes in global carbon cycling. Sudden injection of massive amounts of carbon dioxide into the atmosphere is recorded in C-isotope record of the Early Cretaceous. The Aptian carbon cycle perturbation triggered changes in temperature and in global hydrological cycling. Changes in physical and chemical oceanography are reflected in widespread black shale deposition ("Oceanic Anoxic Event 1a"), in carbonate platform drowning and in biocalcification crises. "Days of future passed" (Moody Blues, 1967) reminds us that the past provides essential information needed for decisions to be made in the interest of mankind's future.

Multi-Scale Observation of Time-Variable Interactions of a Stream and its Valley Bottom During a Storm Event

NASA Astrophysics Data System (ADS)

Hixson, J.; Ward, A. S.; Schmadel, N.

2015-12-01

The exchange of water and solutes across the stream-hyporheic-riparian-hillslope continuum is controlled by the interaction of dynamic hydrological processes with the underlying geological setting. Our current understanding of exchange processes is primarily based on field observations collected during baseflow conditions, with few studies considering time-variable stream-aquifer interactions during storm events. We completed ten sets of four in-stream tracer slug injections during and after a large storm event in a headwater catchment at the H.J. Andrews Experimental Forest, Oregon. The injections were performed in three adjacent 50-meter study reaches, enabling comparison of spatial heterogeneity in transport processes. Reach-scale data demonstrate apparent trends with discharge in both transient storage and long-term storage (commonly "channel water balance"). Comparison of flowpath-scale observations from a network of monitoring wells to reach-scale observations showed that the advective timescale changed with discharge making it difficult to infer process from simple, reach-scale tracer studies. Overall, our results highlight the opportunities and challenges for interpretation of multi-scale solute tracer data along the stream-hyporheic-riparian-hillslope continuum.

Database for the Geologic Map of the Skykomish River 30-Minute by 60-Minute Quadrangle, Washington (I-1963)

USGS Publications Warehouse

Tabor, R.W.; Frizzell, V.A.; Booth, D.B.; Waitt, R.B.; Whetten, J.T.; Zartman, R.E.

2006-01-01

This digital map database has been prepared from the published geologic map of the Skykomish River 30- by 60-minute quadrangle by the senior author. Together with the accompanying text files as PDF, it provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The authors mapped most of the bedrock geology at 1:100,000 scale, but compiled Quaternary units at 1:24,000 scale. The Quaternary contacts and structural data have been much simplified for the 1:100,000-scale map and database. The spatial resolution (scale) of the database is 1:100,000 or smaller. From the eastern-most edges of suburban Seattle, the Skykomish River quadrangle stretches east across the low rolling hills and broad river valleys of the Puget Lowland, across the forested foothills of the North Cascades, and across high meadowlands to the bare rock peaks of the Cascade crest. The Straight Creek Fault, a major Pacific Northwest structure which almost bisects the quadrangle, mostly separates unmetamorphosed and low-grade metamorphic Paleozoic and Mesozoic oceanic rocks on the west from medium- to high-grade metamorphic rocks on the east. Within the quadrangle the lower grade rocks are mostly Mesozoic melange units. To the east, the higher-grade terrane is mostly the Chiwaukum Schist and related gneisses of the Nason terrane and invading mid-Cretaceous stitching plutons. The Early Cretaceous Easton Metamorphic Suite crops out on both sides of the Straight Creek fault and records it's dextral displacement. On the south margin of the quadrangle, the fault separates the lower Eocene Swauk Formation on the east from the upper Eocene and Oligocene(?) Naches Formation and, farther north, its correlative Barlow Pass Volcanics the west. Stratigraphically equivalent rocks of the Puget Group crop out farther to the west. Rocks of the Cascade magmatic arc are mostly represented by Miocene and Oligocene plutons, including the Grotto, Snoqualmie, and Index batholiths. Alpine river valleys in the quadrangle record multiple advances and retreats of alpine glaciers. Multiple advances of the Cordilleran ice sheet, originating in the mountains of British Columbia, Canada, have left an even more complex sequence of outwash and till along the western mountain front, up these same alpine river valleys, and over the Puget Lowland. This database and accompanying plot files depict the distribution of geologic materials and structures at a regional (1:100,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains new information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Geologic map of Yosemite National Park and vicinity, California

USGS Publications Warehouse

Huber, N.K.; Bateman, P.C.; Wahrhaftig, Clyde

1989-01-01

This digital map database represents the general distribution of bedrock and surficial deposits of the Yosemite National Park vicinity. It was produced directly from the file used to create the print version in 1989. The Yosemite National Park region is comprised of portions of 15 7.5 minute quadrangles. The original publication of the map in 1989 included the map, described map units and provided correlations, as well as a geologic summary and references, all on the same sheet. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:125,000 or smaller.

Geologic map and map database of northeastern San Francisco Bay region, California, [including] most of Solano County and parts of Napa, Marin, Contra Costa, San Joaquin, Sacramento, Yolo, and Sonoma Counties

USGS Publications Warehouse

Graymer, Russell Walter; Jones, David Lawrence; Brabb, Earl E.

2002-01-01

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (nesfmf.ps, nesfmf.pdf, nesfmf.txt), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:62,500 or smaller.

Geologic Mapping of the Medusae Fossae Formation, Mars, and the Northern Lowland Plains, Venus

NASA Technical Reports Server (NTRS)

Zimbelman, J. R.

2010-01-01

This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geologic maps, generated under an earlier PGG mapping grant.

USGS national surveys and analysis projects: Preliminary compilation of integrated geological datasets for the United States

USGS Publications Warehouse

Nicholson, Suzanne W.; Stoeser, Douglas B.; Wilson, Frederic H.; Dicken, Connie L.; Ludington, Steve

2007-01-01

The growth in the use of Geographic nformation Systems (GS) has highlighted the need for regional and national digital geologic maps attributed with age and rock type information. Such spatial data can be conveniently used to generate derivative maps for purposes that include mineral-resource assessment, metallogenic studies, tectonic studies, human health and environmental research. n 1997, the United States Geological Survey’s Mineral Resources Program initiated an effort to develop national digital databases for use in mineral resource and environmental assessments. One primary activity of this effort was to compile a national digital geologic map database, utilizing state geologic maps, to support mineral resource studies in the range of 1:250,000- to 1:1,000,000-scale. Over the course of the past decade, state databases were prepared using a common standard for the database structure, fields, attributes, and data dictionaries. As of late 2006, standardized geological map databases for all conterminous (CONUS) states have been available on-line as USGS Open-File Reports. For Alaska and Hawaii, new state maps are being prepared, and the preliminary work for Alaska is being released as a series of 1:500,000-scale regional compilations. See below for a list of all published databases.

Geologic map of the San Bernardino North 7.5' quadrangle, San Bernardino County, California

USGS Publications Warehouse

Miller, F.K.; Matti, J.C.

2001-01-01

3. Portable Document Format (.pdf) files of: a. This Readme; includes an Appendix, containing data found in sbnorth_met.txt . b. The Description of Map Units identical to that found on the plot of the PostScript file. c. The same graphic as plotted in 2 above. (Test plots from this .pdf do not produce 1:24,000-scale maps. Use Adobe Acrobat pagesize setting to control map scale.) The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Miscellaneous Investigations Series (I-series) maps. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. Even though this is an author-prepared report, every attempt has been made to closely adhere to the stratigraphic nomenclature of the U. S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above). If roads in some areas, especially forest roads that parallel topographic contours, do not show well on plots of the geologic map, we recommend use of the USGS San Bernardino North 7.5’ topographic quadrangle in conjunction with the geologic map.

Structure and kinematics of segment-scale crustal accretion processes in Iceland and implications for analogous mid-ocean ridge systems

NASA Astrophysics Data System (ADS)

Siler, Drew Lorenz

2011-12-01

The sub-surface geologic structure of the crust is controlled by the magmatic and tectonic processes that construct the crust during plate spreading. As a result, geologic structure provides constraints on the processes that occur during plate spreading. The crust of the Skagi region of northern Iceland, where this study was focused, was accreted by magmatic construction to Iceland ˜7-10 Ma and subsequently glacially eroded, exhuming ˜1-3 km of structural relief. Continuous spreading-parallel and spreading-orthogonal mountain ranges expose the crust accreted at discrete spreading segments, the fundamental intervals upon which plate spreading and crustal accretion occur. As a result, Skagi is an ideal location to employ geologic structure analysis to study magmatic rifting processes. Within spreading segments structural patterns vary significantly between segment centers and distal fissure swarms. While segment centers are characterized by focused magmatic construction and km-scale sub-volcanic subsidence, fissure swarms are characterized by limited magmatic construction, minor sub-axial subsidence and lateral dike injection. Such along-strike variation indicates that both magma in the upper crust and gabbroic material in the lower crust must be redistributed along-strike within spreading segments during plate spreading. Material flow is directed from beneath segment centers towards distal fissure swarms. At the regional scale, each spreading segment is a structurally discrete interval of Iceland's Neovolcanic Zone. As a result of west-northwestward movement of Iceland relative to the Iceland hotspot, the rift zone axis has progressively relocated to the east-southeast with time, leaving a series of abandoned rift zones throughout western Iceland. A compilation of published K/Ar and 40Ar/39Ar age data and geologic data from across northern Iceland shows that rift relocation occurs via frequent (2-3 Ma), small-scale (˜20 km) rift propagations rather than rare, 100s of km 'rift jumps' as is conventional models suggest. The structure relationships we define in the Icelandic crust are similar to that of other magmatic rift systems including Mid-Ocean Ridges, continental rifts and ancient volcanic rift margins. As such, we suggest that many of the crustal accretion processes we have inferred from Icelandic data may be important in these analogous environments as well.

Characterizing spatial and temporal variability in methane gas-flux dynamics of subtropical wetlands in the Big Cypress National Preserve, Florida

NASA Astrophysics Data System (ADS)

Sirianni, M.; Comas, X.; Shoemaker, B.

2017-12-01

Wetland methane emissions are highly variable both in space and time, and are controlled by changes in certain biogeochemical controls (i.e. organic matter availability; redox potential) and/or other environmental factors (i.e. soil temperature; water level). Consequently, hot spots (areas with disproportionally high emissions) may develop where biogeochemical and environmental conditions are especially conducive for enhancing certain microbial processes such as methanogenesis. The Big Cypress National Preserve is a collection of subtropical wetlands in southwestern Florida, including extensive forested (cypress, pine, hardwood) and sawgrass ecosystems that dry and flood annually in response to rainfall. In addition to rainfall, hydroperiod, fire regime, elevation above mean sea level, dominant vegetation type and underlying geological controls contribute to the development and evolution of organic and calcitic soils found throughout the Preserve. Currently, the U.S. Geological Survey employs eddy covariance methods within the Preserve to quantify carbon and methane exchanges over several spatially extensive vegetation communities. While eddy covariance towers are a convenient tool for measuring gas exchanges at the ecosystem scale, their spatially extensive footprint (hundreds of meters) may mask smaller scale spatial variabilities that may be conducive to the development of hot spots. Similarly, temporal resolution (i.e. sampling effort) at scales smaller that the eddy covariance measurement footprint is important since low resolution data may overlook rapid emission events and the temporal variability of discrete hot spots. In this work, we intend to estimate small-scale contributions of organic and calcitic soils to gas exchanges measured by the eddy covariance towers using a unique combination of ground penetrating radar (GPR), capacitance probes, gas traps, and time-lapse photography. By using an array of methods that vary in spatio-temporal resolution, we hope to better understand the uncertainties associated with measuring wetland methane fluxes across different spatial and temporal scales. Our results have implications for characterizing and refining methane flux estimates in subtropical peat soils that could be used for climate models.

Early Paleogene Orbital Variations in Atmospheric CO2 and New Astronomical Solutions

NASA Astrophysics Data System (ADS)

Zeebe, R. E.

2017-12-01

Geologic records across the globe show prominent variations on orbital time scales during numerous epochs going back hundreds of millions of years. The origin of the Milankovic cycles are variations in orbital parameters of the bodies of the Solar System. On long time scales, the orbital variations can not be computed analytically because of the chaotic nature of the Solar System. Thus, numerical solutions are used to estimate changes in, e.g., Earth's orbital parameters in the past. The orbital solutions represent the backbone of cyclostratigraphy and astrochronology, now widely used in geology and paleoclimatology. Hitherto only two solutions for Earth's eccentricity appear to be used in paleoclimate studies, provided by two different groups that integrated the full Solar System equations over the past >100 Myr. In this presentation, I will touch on the basic physics behind, and present new results of, accurate Solar System integrations for Earth's eccentricity over the past hundred million years. I will discuss various limitations within the framework of the present simulations and compare the results to existing solutions. Furthermore, I will present new results from practical applications of such orbital solutions, including effects of orbital forcing on coupled climate- and carbon cycle variations. For instance, we have recently revealed a mechanism for a large lag between changes in carbon isotope ratios and eccentricity at the 400-kyr period, which has been observed in Paleocene, Oligocene, and Miocene sections. Finally, I will present the first estimates of orbital-scale variations in atmospheric CO2 during the early Paleogene.

Geology of the Cape Mendocino, Eureka, Garberville, and Southwestern Part of the Hayfork 30 x 60 Minute Quadrangles and Adjacent Offshore Area, Northern California

USGS Publications Warehouse

McLaughlin, Robert J.; Ellen, S.D.; Blake, M.C.; Jayko, Angela S.; Irwin, W.P.; Aalto, K.R.; Carver, G.A.; Clarke, S.H.; Barnes, J.B.; Cecil, J.D.; Cyr, K.A.

2000-01-01

Introduction These geologic maps and accompanying structure sections depict the geology and structure of much of northwestern California and the adjacent continental margin. The map area includes the Mendocino triple junction, which is the juncture of the North American continental plate with two plates of the Pacific ocean basin. The map area also encompasses major geographic and geologic provinces of northwestern California. The maps incorporate much previously unpublished geologic mapping done between 1980 and 1995, as well as published mapping done between about 1950 and 1978. To construct structure sections to mid-crustal depths, we integrate the surface geology with interpretations of crustal structure based on seismicity, gravity and aeromagnetic data, offshore structure, and seismic reflection and refraction data. In addition to describing major geologic and structural features of northwestern California, the geologic maps have the potential to address a number of societally relevant issues, including hazards from earthquakes, landslides, and floods and problems related to timber harvest, wildlife habitat, and changing land use. All of these topics will continue to be of interest in the region, as changing land uses and population density interact with natural conditions. In these interactions, it is critical that the policies and practices affecting man and the environment integrate an adequate understanding of the geology. This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (ceghmf.ps, ceghmf.pdf, ceghmf.txt), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:100,000 or smaller.

Geological Mapping of the Debussy Quadrangle (H-14) Preliminary Results

NASA Astrophysics Data System (ADS)

Pegg, D. L.; Rothery, D. A.; Balme, M. R.; Conway, S. J.

2018-05-01

We present the current status of geological mapping of the Debussy quadrangle. Mapping underway as part of a program to map the entire planet at a scale of 1:3M using MESSENGER data in preparation for the BepiColombo mission.

Building a Geologic Map of Neptune's Moon Triton

NASA Astrophysics Data System (ADS)

Martin, E. S.; Patthoff, D. A.; Bland, M. T.; Watters, T. R.; Collins, G. C.; Becker, T.

2018-06-01

Triton serves as a bridge between KBOs and icy satellites, and characterization of its terrains is important for advancing comparative planetological studies. We aim to create a geologic map of the Neptune-facing side of Triton at a scale of 1:5M.

OneGeology: Making the World’s Geological Map Data Accessible Online

NASA Astrophysics Data System (ADS)

Broome, H.; Jackson, I.; Robida, F.; Thorleifson, H.

2009-12-01

OneGeology (http://onegeology.org) is a successful international initiative of the geological surveys of the world and the flagship project of the ‘International Year of Planet Earth’. Its aim is to provide dynamic web access to geological map data covering the world, creating a focus for accessing geological information for everyone. Thanks to the enthusiasm and support of participating nations the initiative has progressed rapidly and geological surveys and the many users of their data are excited about this ground-breaking project. Currently 10 international geoscience organizations have endorsed the initiative and more than 109 countries have agreed to participate. OneGeology works with whatever digital format is available in each country. The target scale is 1:1 million, but the project is pragmatic and accepts a range of scales and the best available data. The initiative recognizes that different nations have differing abilities to participate and transfer of know-how to those who need it is a key aspect of the approach. A key contributor to the success of OneGeology has been its utilization of the latest new web technology and an emerging data exchange standard for geological map data called GeoSciML. GeoSciML (GeoScience Markup Language) is a schema written in GML (Geography Markup Language) for geological data. GeoSciML has the ability to represent both the geography (geometries e.g. polygons, lines and points) and geological attribution in a clear and structured format. OneGeology was launched March 2007 at the inaugural workshop in Brighton England. At that workshop the 43 participating nations developed a declaration of a common objective and principles called the “Brighton Accord” (http://onegeology.org/what_is/accord.html) . Work was initiated immediately and the resulting OneGeology Portal was launched at the International Geological Congress in Oslo in August 2008 by Simon Winchester, author of “The Map that Changed the World”. Since the successful launch, OneGeology participants have continued working both to increase national participation and content, and to put in place a more formal governance structure to oversee the long term evolution of the initiative. OneGeology is an example of collaboration in action and is both multilateral and multinational. In 2007, a group of motivated geoscientists and data managers identified an opportunity and took the initiative to engage their peers to work in concert to achieve a shared objective. OneGeology has facilitated collaborative development of an Internet site that provides unprecedented online access to global geological map data.

3D Geological Model for "LUSI" - a Deep Geothermal System

NASA Astrophysics Data System (ADS)

Sohrabi, Reza; Jansen, Gunnar; Mazzini, Adriano; Galvan, Boris; Miller, Stephen A.

2016-04-01

Geothermal applications require the correct simulation of flow and heat transport processes in porous media, and many of these media, like deep volcanic hydrothermal systems, host a certain degree of fracturing. This work aims to understand the heat and fluid transport within a new-born sedimentary hosted geothermal system, termed Lusi, that began erupting in 2006 in East Java, Indonesia. Our goal is to develop conceptual and numerical models capable of simulating multiphase flow within large-scale fractured reservoirs such as the Lusi region, with fractures of arbitrary size, orientation and shape. Additionally, these models can also address a number of other applications, including Enhanced Geothermal Systems (EGS), CO2 sequestration (Carbon Capture and Storage CCS), and nuclear waste isolation. Fractured systems are ubiquitous, with a wide-range of lengths and scales, making difficult the development of a general model that can easily handle this complexity. We are developing a flexible continuum approach with an efficient, accurate numerical simulator based on an appropriate 3D geological model representing the structure of the deep geothermal reservoir. Using previous studies, borehole information and seismic data obtained in the framework of the Lusi Lab project (ERC grant n°308126), we present here the first 3D geological model of Lusi. This model is calculated using implicit 3D potential field or multi-potential fields, depending on the geological context and complexity. This method is based on geological pile containing the geological history of the area and relationship between geological bodies allowing automatic computation of intersections and volume reconstruction. Based on the 3D geological model, we developed a new mesh algorithm to create hexahedral octree meshes to transfer the structural geological information for 3D numerical simulations to quantify Thermal-Hydraulic-Mechanical-Chemical (THMC) physical processes.

Geologic map of the Devore 7.5' quadrangle, San Bernardino County, California

USGS Publications Warehouse

Morton, Douglas M.; Matti, Jonathan C.

2001-01-01

This Open-File Report contains a digital geologic map database of the Devore 7.5' quadrangle, San Bernardino County, California, that includes: 1. ARC/INFO (Environmental Systems Research Institute) version 7.2.1 coverages of the various components of the geologic map 2. A PostScript (.ps) file to plot the geologic map on a topographic base, containing a Correlation of Map Units diagram, a Description of Map Units, an index map, and a regional structure map 3. Portable Document Format (.pdf) files of: a. This Readme; includes an Appendix, containing metadata details found in devre_met.txt b. The same graphic as plotted in 2 above. (Test plots from this .pdf do not produce 1:24,000-scale maps. Adobe Acrobat page-size settings control map scale.) The Correlation of Map Units and Description of Map Units are in the editorial format of USGS Miscellaneous Investigations Series maps (I-maps) but have not been edited to comply with I-map standards. Within the geologic-map data package, map units are identified by such standard geologic-map criteria as formation name, age, and lithology. Even though this is an author-prepared report, every attempt has been made to closely adhere to the stratigraphic nomenclature of the U.S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above). If roads in some areas, especially forest roads that parallel topographic contours, do not show well on plots of the geologic map, we recommend use of the USGS Devore 7.5’ topographic quadrangle in conjunction with the geologic map.

Geologic map of the Fifteenmile Valley 7.5' quadrangle, San Bernardino County, California

USGS Publications Warehouse

Miller, F.K.; Matti, J.C.

2001-01-01

Open-File Report OF 01-132 contains a digital geologic map database of the Fifteenmile Valley 7.5’ quadrangle, San Bernardino County, California that includes: 1. ARC/INFO (Environmental Systems Research Institute, http://www.esri.com) version 7.2.1 coverages of the various elements of the geologic map. 2. A PostScript file to plot the geologic map on a topographic base, and containing a Correlation of Map Units diagram, a Description of Map Units, an index map, and a regional structure map. 3. Portable Document Format (.pdf) files of: a. This Readme; includes in Appendix I, data contained in fif_met.txt b. The same graphic as plotted in 2 above. (Test plots have not produced 1:24,000-scale map sheets. Adobe Acrobat pagesize setting influences map scale.) The Correlation of Map Units (CMU) and Description of Map Units (DMU) is in the editorial format of USGS Miscellaneous Investigations Series (I-series) maps. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. Even though this is an author-prepared report, every attempt has been made to closely adhere to the stratigraphic nomenclature of the U. S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above). If roads in some areas, especially forest roads that parallel topographic contours, do not show well on plots of the geologic map, we recommend use of the USGS Fifteenmile Valley 7.5’ topographic quadrangle in conjunction with the geologic map.

Megascale processes: Natural disasters and human behavior

USGS Publications Warehouse

Kieffer, S.W.; Barton, P.; Chesworth, W.; Palmer, A.R.; Reitan, P.; Zen, E.-A.

2009-01-01

Megascale geologic processes, such as earthquakes, tsunamis, volcanic eruptions, floods, and meteoritic impacts have occurred intermittently throughout geologic time, and perhaps on several planets. Unlike other catastrophes discussed in this volume, a unique process is unfolding on Earth, one in which humans may be the driving agent of megadisasters. Although local effects on population clusters may have been catastrophic in the past, human societies have never been interconnected globally at the scale that currently exists. We review some megascale processes and their effects in the past, and compare present conditions and possible outcomes. We then propose that human behavior itself is having effects on the planet that are comparable to, or greater than, these natural disasters. Yet, unlike geologic processes, human behavior is potentially under our control. Because the effects of our behavior threaten the stability, or perhaps even existence, of a civilized society, we call for the creation of a body to institute coherent global, credible, scientifi cally based action that is sensitive to political, economic, religious, and cultural values. The goal would be to institute aggressive monitoring, identify and understand trends, predict their consequences, and suggest and evaluate alternative actions to attempt to rescue ourselves and our ecosystems from catastrophe. We provide a template modeled after several existing national and international bodies. ?? 2009 The Geological Society of America.

Dione's spectral and geological properties

USGS Publications Warehouse

Stephan, K.; Jaumann, R.; Wagner, R.; Clark, R.N.; Cruikshank, D.P.; Hibbitts, C.A.; Roatsch, T.; Hoffmann, H.; Brown, R.H.; Filiacchione, G.; Buratti, B.J.; Hansen, G.B.; McCord, T.B.; Nicholson, P.D.; Baines, K.H.

2010-01-01

We present a detailed analysis of the variations in spectral properties across the surface of Saturn's satellite Dione using Cassini/VIMS data and their relationships to geological and/or morphological characteristics as seen in the Cassini/ISS images. This analysis focuses on a local region on Dione's anti-saturnian hemisphere that was observed by VIMS with high spatial resolution during orbit 16 in October 2005. The results are incorporated into a global context provided by VIMS data acquired within Cassini's first 50 orbits. Our results show that Dione's surface is dominated by at least one global process. Bombardment by magnetospheric particles is consistent with the concentration of dark material and enhanced CO2 absorption on the trailing hemisphere of Dione independent of the geology. Local regions within this terrain indicate a special kind of resurfacing that probably is related to large-scale impact process. In contrast, the enhanced ice signature on the leading side is associated with the extended ejecta of the fresh impact crater Creusa (???49??N/76??W). Although no geologically active regions could be identified, Dione's tectonized regions observed with high spatial resolution partly show some clean H2O ice implying that tectonic processes could have continued into more recent times. ?? 2009 Elsevier Inc. All rights reserved.

Geologic time

USGS Publications Warehouse

Newman, William L.

2000-01-01

The Earth is very old 4 1/2 billion years or more according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.

Geologic Map and Map Database of the Oakland Metropolitan Area, Alameda, Contra Costa, and San Francisco Counties, California

USGS Publications Warehouse

Graymer, R.W.

2000-01-01

Introduction This report contains a new geologic map at 1:50,000 scale, derived from a set of geologic map databases containing information at a resolution associated with 1:24,000 scale, and a new description of geologic map units and structural relationships in the mapped area. The map database represents the integration of previously published reports and new geologic mapping and field checking by the author (see Sources of Data index map on the map sheet or the Arc-Info coverage pi-so and the textfile pi-so.txt). The descriptive text (below) contains new ideas about the Hayward fault and other faults in the East Bay fault system, as well as new ideas about the geologic units and their relations. These new data are released in digital form in conjunction with the Federal Emergency Management Agency Project Impact in Oakland. The goal of Project Impact is to use geologic information in land-use and emergency services planning to reduce the losses occurring during earthquakes, landslides, and other hazardous geologic events. The USGS, California Division of Mines and Geology, FEMA, California Office of Emergency Services, and City of Oakland participated in the cooperative project. The geologic data in this report were provided in pre-release form to other Project Impact scientists, and served as one of the basic data layers for the analysis of hazard related to earthquake shaking, liquifaction, earthquake induced landsliding, and rainfall induced landsliding. The publication of these data provides an opportunity for regional planners, local, state, and federal agencies, teachers, consultants, and others outside Project Impact who are interested in geologic data to have the new data long before a traditional paper map could be published. Because the database contains information about both the bedrock and surficial deposits, it has practical applications in the study of groundwater and engineering of hillside materials, as well as the study of geologic hazards and the academic research on the geologic history and development of the region.

The role of impact cratering for Mars sample return

NASA Technical Reports Server (NTRS)

Schultz, P. H.

1988-01-01

The preserved cratering record of Mars indicates that impacts play an important role in deciphering Martian geologic history, whether as a mechanism to modify the lithosphere and atmosphere or as a tool to sample the planet. The various roles of impact cratering in adding a broader understanding of Mars through returned samples are examined. Five broad roles include impact craters as: (1) a process in response to a different planetary localizer environment; (2) a probe for excavating crustal/mantle materials; (3) a possible localizer of magmatic and hydrothermal processes; (4) a chronicle of changes in the volcanic, sedimentary, atmospheric, and cosmic flux history; and (5) a chronometer for extending the geologic time scale to unsampled regions. The evidence for Earth-like processes and very nonlunar styles of volcanism and tectonism may shift the emphasis of a sampling strategy away from equally fundamental issues including crustal composition, unit ages, and climate history. Impact cratering not only played an important active role in the early Martian geologic history, it also provides an important tool for addressing such issues.

Three-Dimensional Online Visualization and Engagement Tools for the Geosciences

NASA Astrophysics Data System (ADS)

Cockett, R.; Moran, T.; Pidlisecky, A.

2013-12-01

Educational tools often sacrifice interactivity in favour of scalability so they can reach more users. This compromise leads to tools that may be viewed as second tier when compared to more engaging activities performed in a laboratory; however, the resources required to deliver laboratory exercises that are scalable is often impractical. Geoscience education is well situated to benefit from interactive online learning tools that allow users to work in a 3D environment. Visible Geology (http://3ptscience.com/visiblegeology) is an innovative web-based application designed to enable visualization of geologic structures and processes through the use of interactive 3D models. The platform allows users to conceptualize difficult, yet important geologic principles in a scientifically accurate manner by developing unique geologic models. The environment allows students to interactively practice their visualization and interpretation skills by creating and interacting with their own models and terrains. Visible Geology has been designed from a user centric perspective resulting in a simple and intuitive interface. The platform directs students to build there own geologic models by adding beds and creating geologic events such as tilting, folding, or faulting. The level of ownership and interactivity encourages engagement, leading learners to discover geologic relationships on their own, in the context of guided assignments. In January 2013, an interactive geologic history assignment was developed for a 700-student introductory geology class at The University of British Columbia. The assignment required students to distinguish the relative age of geologic events to construct a geologic history. Traditionally this type of exercise has been taught through the use of simple geologic cross-sections showing crosscutting relationships; from these cross-sections students infer the relative age of geologic events. In contrast, the Visible Geology assignment offers students a unique experience where they first create their own geologic events allowing them to directly see how the timing of a geologic event manifests in the model and resulting cross-sections. By creating each geologic event in the model themselves, the students gain a deeper understanding of the processes and relative order of events. The resulting models can be shared amongst students, and provide instructors with a basis for guiding inquiry to address misconceptions. The ease of use of the assignment, including automatic assessment, made this tool practical for deployment in this 700 person class. The outcome of this type of large scale deployment is that students, who would normally not experience a lab exercise, gain exposure to interactive 3D thinking. Engaging tools and software that puts the user in control of their learning experiences is critical for moving to scalable, yet engaging, online learning environments.

Geological Corrections in Gravimetry

NASA Astrophysics Data System (ADS)

Mikuška, J.; Marušiak, I.

2015-12-01

Applying corrections for the known geology to gravity data can be traced back into the first quarter of the 20th century. Later on, mostly in areas with sedimentary cover, at local and regional scales, the correction known as gravity stripping has been in use since the mid 1960s, provided that there was enough geological information. Stripping at regional to global scales became possible after releasing the CRUST 2.0 and later CRUST 1.0 models in the years 2000 and 2013, respectively. Especially the later model provides quite a new view on the relevant geometries and on the topographic and crustal densities as well as on the crust/mantle density contrast. Thus, the isostatic corrections, which have been often used in the past, can now be replaced by procedures working with an independent information interpreted primarily from seismic studies. We have developed software for performing geological corrections in space domain, based on a-priori geometry and density grids which can be of either rectangular or spherical/ellipsoidal types with cells of the shapes of rectangles, tesseroids or triangles. It enables us to calculate the required gravitational effects not only in the form of surface maps or profiles but, for instance, also along vertical lines, which can shed some additional light on the nature of the geological correction. The software can work at a variety of scales and considers the input information to an optional distance from the calculation point up to the antipodes. Our main objective is to treat geological correction as an alternative to accounting for the topography with varying densities since the bottoms of the topographic masses, namely the geoid or ellipsoid, generally do not represent geological boundaries. As well we would like to call attention to the possible distortions of the corrected gravity anomalies. This work was supported by the Slovak Research and Development Agency under the contract APVV-0827-12.

Steady, modest slip over multiple earthquake cycles on the Owens Valley and Little Lake fault zones

NASA Astrophysics Data System (ADS)

Amos, C. B.; Haddon, E. K.; Burgmann, R.; Zielke, O.; Jayko, A. S.

2015-12-01

A comprehensive picture of current plate-boundary deformation requires integration of short-term geodetic records with longer-term geologic strain. Comparing rates of deformation across these time intervals highlights potential time-dependencies in both geodetic and geologic records and yields critical insight into the earthquake deformation process. The southern Walker Lane Belt in eastern California represents one location where short-term strain recorded by geodesy apparently outpaces longer-term geologic fault slip measured from displaced rocks and landforms. This discrepancy persists both for individual structures and across the width of the deforming zone, where ~1 cm/yr of current dextral shear exceeds Quaternary slip rates summed across individual faults. The Owens Valley and Little Lake fault systems form the western boundary of the southern Walker Lane and host a range of published slip rate estimates from ~1 - 7 mm/yr over varying time intervals based on both geodetic and geologic measurements. New analysis of offset geomorphic piercing lines from airborne lidar and field measurements along the Owens Valley fault provides a snapshot of deformation during individual earthquakes and over many seismic cycles. Viewed in context of previously reported ages from pluvial and other landforms in Owens Valley, these offsets suggest slip rates of ~0.6 - 1.6 mm/yr over the past 103 - 105 years. Such rates agree with similar estimates immediately to the south on the Little Lake fault, where lidar measurements indicate dextral slip averaging ~0.6 - 1.3 mm/yr over comparable time intervals. Taken together, these results suggest steady, modest slip in the absence of significant variations over the Mid-to-Late Quaternary for a ~200 km span of the southwestern Walker Lane. Our findings argue against the presence of long-range fault interactions and slip-rate variations for this portion of the larger, regional fault network. This result also suggests that faster slip-rate estimates from geodetic measurements reflect transients over much shorter time scales. Additionally, the persistence of relatively faster geodetic shear in comparison with time-averaged fault slip leaves open the possibility of significant off-fault deformation or slip on subsidiary structures across the Owens Valley.

CO2 storage capacity estimates from fluid dynamics (Invited)

NASA Astrophysics Data System (ADS)

Juanes, R.; MacMinn, C. W.; Szulczewski, M.

2009-12-01

We study a sharp-interface mathematical model for the post-injection migration of a plume of CO2 in a deep saline aquifer under the influence of natural groundwater flow, aquifer slope, gravity override, and capillary trapping. The model leads to a nonlinear advection-diffusion equation, where the diffusive term describes the upward spreading of the CO2 against the caprock. We find that the advective terms dominate the flow dynamics even for moderate gravity override. We solve the model analytically in the hyperbolic limit, accounting rigorously for the injection period—using the true end-of-injection plume shape as an initial condition. We extend the model by incorporating the effect of CO2 dissolution into the brine, which—we find—is dominated by convective mixing. This mechanism enters the model as a nonlinear sink term. From a linear stability analysis, we propose a simple estimate of the convective dissolution flux. We then obtain semi-analytic estimates of the maximum plume migration distance and migration time for complete trapping. Our analytical model can be used to estimate the storage capacity (from capillary and dissolution trapping) at the geologic basin scale, and we apply the model to various target formations in the United States. Schematic of the migration of a CO2 plume at the geologic basin scale. During injection, the CO2 forms a plume that is subject to gravity override. At the end of the injection, all the CO2 is mobile. During the post-injection period, the CO2 migrates updip and also driven by regional groundwater flow. At the back end of the plume, where water displaces CO2, the plume leaves a wake or residual CO2 due to capillary trapping. At the bottom of the moving plume, CO2 dissolves into the brine—a process dominated by convective mixing. These two mechanisms—capillary trapping and convective dissolution—reduce the size of the mobile plume as it migrates. In this communication, we present an analytical model that predicts the migration distance and time for complete trapping. This is used to estimate storage capacity of geologic formations at the basin scale.

Towards a Millennial Time-scale Vertical Deformation Field in Taiwan

NASA Astrophysics Data System (ADS)

Bordovaos, P. A.; Johnson, K. M.

2015-12-01

Pete Bordovalos and Kaj M. Johnson To better understand the feedbacks between erosion and deformation in Taiwan, we need constraints on the millennial time-scale vertical field. Dense GPS and leveling data sets in Taiwan provide measurements of the present-day vertical deformation field over the entire Taiwan island. However, it is unclear how much of this vertical field is transient (varies over earthquake cycle) or steady (over millennial time scale). A deformation model is required to decouple transient from steady deformation. This study takes a look at how the 82 mm/yr of convergence motion between the Eurasian plate and the Philippine Sea plate is distributed across the faults on Taiwan. We build a plate flexure model that consists of all known active faults and subduction zones cutting through an elastic plate supported by buoyancy. We use horizontal and vertical GPS data, leveling data, and geologic surface uplift rates with a Monte Carlo probabilistic inversion method to infer fault slip rates and locking depths on all faults. Using our model we examine how different fault geometries influence the estimates of distribution of slip along faults and deformation patterns.

Predicting redox conditions in groundwater at a regional scale

USGS Publications Warehouse

Tesoriero, Anthony J.; Terziotti, Silvia; Abrams, Daniel B.

2015-01-01

Defining the oxic-suboxic interface is often critical for determining pathways for nitrate transport in groundwater and to streams at the local scale. Defining this interface on a regional scale is complicated by the spatial variability of reaction rates. The probability of oxic groundwater in the Chesapeake Bay watershed was predicted by relating dissolved O2 concentrations in groundwater samples to indicators of residence time and/or electron donor availability using logistic regression. Variables that describe surficial geology, position in the flow system, and soil drainage were important predictors of oxic water. The probability of encountering oxic groundwater at a 30 m depth and the depth to the bottom of the oxic layer were predicted for the Chesapeake Bay watershed. The influence of depth to the bottom of the oxic layer on stream nitrate concentrations and time lags (i.e., time period between land application of nitrogen and its effect on streams) are illustrated using model simulations for hypothetical basins. Regional maps of the probability of oxic groundwater should prove useful as indicators of groundwater susceptibility and stream susceptibility to contaminant sources derived from groundwater.

Geology of the conterminous United States at 1:2,500,000 scale a digital representation of the 1974 P.B. King and H.M. Beikman map

USGS Publications Warehouse

Schruben, Paul G.; Arndt, Raymond E.; Bawiec, Walter J.

1998-01-01

This CD-ROM contains a digital version of the Geologic Map of the United States, originally published at a scale of 1:2,500,000 (King and Beikman, 1974b). It excludes Alaska and Hawaii. In addition to the graphical formats, the map key is included in ASCII text. A geographic information system (GIS) allows combining and overlaying of layers for analysis of spatial relations not readily apparent in the standard paper publication. This disc contains only geology. However, digital data on geology, geophysics, and geochemistry can be combined to create useful derivative products-- for example, see Phillips and others (1993). This CD-ROM contains a copy of the text and figures from Professional Paper 901 by King and Beikman (1974a). This text describes the historical background of the map, details of the compilation process, and limitations to interpretation. The digital version of the text can be searched for keywords or phrases.

Integrated analysis of remote sensing products from basic geological surveys. [Brazil

NASA Technical Reports Server (NTRS)

Dasilvafagundesfilho, E. (Principal Investigator)

1984-01-01

Recent advances in remote sensing led to the development of several techniques to obtain image information. These techniques as effective tools in geological maping are analyzed. A strategy for optimizing the images in basic geological surveying is presented. It embraces as integrated analysis of spatial, spectral, and temporal data through photoptic (color additive viewer) and computer processing at different scales, allowing large areas survey in a fast, precise, and low cost manner.

Bedrock geologic map of the Hartland and North Hartland quadrangles, Windsor County, Vermont, and Sullivan and Grafton Counties, New Hampshire

USGS Publications Warehouse

Walsh, Gregory J.

2016-08-16

This report consists of sheets 1 and 2 as well as an online geographic information systems database that includes contacts of bedrock geologic units, faults, outcrops, structural geologic information, and photographs. Sheet 2 of this report shows three cross sections, a tectonic map, and two brittle features maps that show measured outcrop-scale strike and dip results with summary stereonets and rose diagrams.

Geologic Mapping of the Medusae Fossae Formation on Mars and the Northern Lowland Plains of Venus

NASA Technical Reports Server (NTRS)

Zimbelman, J. R.

2009-01-01

This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geo-logic maps, generated under an earlier PGG mapping grant.

A multi-scale permafrost investigation along the Alaska Highway Corridor based on airborne electromagnetic and auxiliary geophysical data

NASA Astrophysics Data System (ADS)

Minsley, B. J.; Kass, M. A.; Bloss, B.; Pastick, N.; Panda, S. K.; Smith, B. D.; Abraham, J. D.; Burns, L. E.

2012-12-01

More than 8000 square kilometers of airborne electromagnetic (AEM) data were acquired along the Alaska Highway Corridor in 2005-2006 by the Alaska Department of Natural Resources Division of Geological and Geophysical Surveys. Because this large AEM dataset covers diverse geologic and permafrost settings, it is an excellent testbed for studying the electrical geophysical response from a wide range of subsurface conditions. These data have been used in several recent investigations of geology, permafrost, and infrastructure along the highway corridor. In this study, we build on existing interpretations of permafrost features by re-inverting the AEM data using traditional least squares inversion techniques as well as recently developed stochastic methods aimed at quantifying uncertainty in geophysical data. Ground-based geophysical measurements, including time-domain electromagnetic soundings, surface nuclear magnetic resonance soundings, and shallow frequency-domain electromagnetic profiles, have also been acquired to help validate and extend the AEM interpretations. Here, we focus on the integration of different types of data to yield an improved characterization of permafrost, including: methods to discriminate between geologic and thermal controls on resistivity; identifying relationships between shallow resistivity and active layer thickness by incorporating auxiliary remote sensing data and ground-based measurements; quantifying apparent slope-aspect-resistivity relationships, where south-facing slopes appear less resistive than north-facing slopes within similar geologic settings; and investigating an observed decrease in resistivity beneath several areas associated with recent fires.

Lithology and aggregate quality attributes for the digital geologic map of Colorado

USGS Publications Warehouse

Knepper, Daniel H.; Green, Gregory N.; Langer, William H.

1999-01-01

This geologic map was prepared as a part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Colorado (Tweto 1979). Consequently the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the state base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1979 geologic map.

OneGeology Web Services and Portal as a global geological SDI - latest standards and technology

NASA Astrophysics Data System (ADS)

Duffy, Tim; Tellez-Arenas, Agnes

2014-05-01

The global coverage of OneGeology Web Services (www.onegeology.org and portal.onegeology.org) achieved since 2007 from the 120 participating geological surveys will be reviewed and issues arising discussed. Recent enhancements to the OneGeology Web Services capabilities will be covered including new up to 5 star service accreditation scheme utilising the ISO/OGC Web Mapping Service standard version 1.3, core ISO 19115 metadata additions and Version 2.0 Web Feature Services (WFS) serving the new IUGS-CGI GeoSciML V3.2 geological web data exchange language standard (http://www.geosciml.org/) with its associated 30+ IUGS-CGI available vocabularies (http://resource.geosciml.org/ and http://srvgeosciml.brgm.fr/eXist2010/brgm/client.html). Use of the CGI simpelithology and timescale dictionaries now allow those who wish to do so to offer data harmonisation to query their GeoSciML 3.2 based Web Feature Services and their GeoSciML_Portrayal V2.0.1 (http://www.geosciml.org/) Web Map Services in the OneGeology portal (http://portal.onegeology.org). Contributing to OneGeology involves offering to serve ideally 1:1000,000 scale geological data (in practice any scale now is warmly welcomed) as an OGC (Open Geospatial Consortium) standard based WMS (Web Mapping Service) service from an available WWW server. This may either be hosted within the Geological Survey or a neighbouring, regional or elsewhere institution that offers to serve that data for them i.e. offers to help technically by providing the web serving IT infrastructure as a 'buddy'. OneGeology is a standards focussed Spatial Data Infrastructure (SDI) and works to ensure that these standards work together and it is now possible for European Geological Surveys to register their INSPIRE web services within the OneGeology SDI (e.g. see http://www.geosciml.org/geosciml/3.2/documentation/cookbook/INSPIRE_GeoSciML_Cookbook%20_1.0.pdf). The Onegeology portal (http://portal.onegeology.org) is the first port of call for anyone wishing to discover the availability of global geological web services and has new functionality to view and use such services including multiple projection support. KEYWORDS : OneGeology; GeoSciML V 3.2; Data exchange; Portal; INSPIRE; Standards; OGC; Interoperability; GeoScience information; WMS; WFS; Cookbook.

Biotic transitions in global marine diversity

NASA Technical Reports Server (NTRS)

Miller, A. I.

1998-01-01

Long-term transitions in the composition of Earth's marine biota during the Phanerozoic have historically been explained in two different ways. One view is that they were mediated through biotic interactions among organisms played out over geologic time. The other is that mass extinctions transcended any such interactions and governed diversity over the long term by resetting the relative diversities of higher taxa. However, a growing body of evidence suggests that macroevolutionary processes effecting biotic transitions during background times were not fundamentally different from those operating during mass extinctions. Physical perturbations at many geographic scales combined to produce the long-term trajectory of Phanerozoic diversity.

Major- and Trace-Element Concentrations in Soils from Northern California: Results from the Geochemical Landscapes Project Pilot Study

USGS Publications Warehouse

Morrison, Jean M.; Goldhaber, Martin B.; Holloway, JoAnn M.; Smith, David B.

2008-01-01

In 2004, the U.S. Geological Survey (USGS), the Geological Survey of Canada (GSC), and the Mexican Geological Survey (Servicio Geologico Mexicano, or SGM) initiated pilot studies in preparation for a soil geochemical survey of North America called the Geochemical Landscapes Project. The purpose of this project is to provide a better understanding of the variability in chemical composition of soils in North America. The data produced by this survey will be used to construct baseline geochemical maps for regions within the continent. Two initial pilot studies were conducted: (1) a continental-scale study involving a north-south and east-west transect across North America and (2) a regional-scale study. The pilot studies were intended to test and refine sample design, sampling protocols, and field logistics for the full continental soils geochemical survey. Smith and others (2005) reported the results from the continental-scale pilot study. The regional-scale California study was designed to represent more detailed, higher resolution geochemical investigations in a region of particular interest that was identified from the low-sample-density continental-scale survey. A 20,000-km2 area of northern California (fig. 1), representing a wide variety of topography, climate, and ecoregions, was chosen for the regional-scale pilot study. This study area also contains diverse geology and soil types and supports a wide range of land uses including agriculture in the Sacramento Valley, forested areas in portions of the Sierra Nevada, and urban/suburban centers such as Sacramento, Davis, and Stockton. Also of interest are potential effects on soil geochemistry from historical hard rock and placer gold mining in the foothills of the Sierra Nevada, historical mercury mining in the Coast Range, and mining of base-metal sulfide deposits in the Klamath Mountains to the north. This report presents the major- and trace-element concentrations from the regional-scale soil geochemical survey in northern California.

A reconnaissance method for delineation of tracts for regional-scale mineral-resource assessment based on geologic-map data

USGS Publications Warehouse

Raines, G.L.; Mihalasky, M.J.

2002-01-01

The U.S. Geological Survey (USGS) is proposing to conduct a global mineral-resource assessment using geologic maps, significant deposits, and exploration history as minimal data requirements. Using a geologic map and locations of significant pluton-related deposits, the pluton-related-deposit tract maps from the USGS national mineral-resource assessment have been reproduced with GIS-based analysis and modeling techniques. Agreement, kappa, and Jaccard's C correlation statistics between the expert USGS and calculated tract maps of 87%, 40%, and 28%, respectively, have been achieved using a combination of weights-of-evidence and weighted logistic regression methods. Between the experts' and calculated maps, the ranking of states measured by total permissive area correlates at 84%. The disagreement between the experts and calculated results can be explained primarily by tracts defined by geophysical evidence not considered in the calculations, generalization of tracts by the experts, differences in map scales, and the experts' inclusion of large tracts that are arguably not permissive. This analysis shows that tracts for regional mineral-resource assessment approximating those delineated by USGS experts can be calculated using weights of evidence and weighted logistic regression, a geologic map, and the location of significant deposits. Weights of evidence and weighted logistic regression applied to a global geologic map could provide quickly a useful reconnaissance definition of tracts for mineral assessment that is tied to the data and is reproducible. ?? 2002 International Association for Mathematical Geology.

Archive of digital chirp subbottom profile data collected during USGS cruise 11BIM01 Offshore of the Chandeleur Islands, Louisiana, June 2011

USGS Publications Warehouse

Forde, Arnell S.; Dadisman, Shawn V.; Miselis, Jennifer L.; Flocks, James G.; Wiese, Dana S.

2013-01-01

From June 3 to 13, 2011, the U.S. Geological Survey conducted a geophysical survey to investigate the geologic controls on barrier island framework and long-term sediment transport along the oil spill mitigation sand berm constructed at the north end and just offshore of the Chandeleur Islands, LA. This effort is part of a broader USGS study, which seeks to better understand barrier island evolution over medium time scales (months to years). This report serves as an archive of unprocessed digital chirp subbottom data, trackline maps, navigation files, Geographic Information System (GIS) files, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FGDC) metadata. Gained (showing a relative increase in signal amplitude) digital images of the seismic profiles are also provided.

The scaling law of climate change and its relevance to assessing (palaeo)biological responses

NASA Astrophysics Data System (ADS)

Kiessling, Wolfgang; Eichenseer, Kilian

2014-05-01

It is often argued that current rates of climate change are unprecedented in the geological past. At the same time, the magnitudes of change were often much greater in deep time than they are in history. The most severe global warming in the Phanerozoic, with dramatic consequences for life, probably occurred across the Permian-Triassic (P-T) boundary when an increase of tropical water temperatures of 15° C has been observed to occur over a timespan 0.8 myr (Sun et al. 2012), whereas global ocean warming over the last 50 years was 0.35° C (Burrows et al. 2011). When transforming these data into rates of change the P-T rate was roughly 370 times smaller than the current rate. We argue that the smaller rates of change inferred from geological proxy records are due to a scaling effect, that is, rates of climate change generally decrease with timespan of observation. We compiled from the published literature data on measured or inferred temperature changes and the timespans over which these changes were assessed. Our compilation currently comprises 120 values and covers timespans from 20 to 107 years. A log-log plot of timespan versus rate of temperature change depicts a highly significant correlation (r2 = 0.95) of a power-law relationship with an exponent of -0.87. Warming trends show a slightly lower exponent (-0.84) than cooling trends (-0.89) but the explained variance is better for the scaling of warming trends. Importantly, the scaled warming trend across the P-T boundary is higher than the current rates of warming. Similar scaling effects are well explored for sediment accumulation rates (Sadler 1981) and evolutionary rates (Gingerich 1993). These have been interpreted as being due to breaks in sedimentation and periods of stasis or transient reversals, respectively. In case of climate change, transient reversals in general trends are the most likely explanation for the scaling relationship. Even relatively rapid intervals of warming, such as the Pleistocene interglacials, are not monotonic, but punctuated by short-term cooling intervals. The fossil record tells us that biodiversity responded dramatically to ancient intervals of climate warming. We can now see that the apparently slower rates of change in some mass extinctions (Permian-Triassic, Triassic-Jurassic) were greater than today when the scaling law is considered. This reassures us that studying deep time patterns of organismic response to climate change is a worthwhile endeavor that is relevant for predicting the future. References Burrows, M. T., Schoeman, D. S., Buckley, L. B., Moore, P., Poloczanska, E. S., Brander, K. M., Brown, C., Bruno, J. F., Duarte, C. M., Halpern, B. S., Holding, J., Kappel, C. V., Kiessling, W., O'Connor, M. I., Pandolfi, J. M., Parmesan, C., Schwing, F. B., Sydeman, W. J., and Richardson, A. J.: The pace of shifting climate in marine and terrestrial ecosystems, Science, 334, 652-655, 2011. Gingerich, P. D.: Quantification and comparison of evolutionary rates, American Journal of Science, 293A, 453-478, 1993. Sadler, P. M.: Sediment accumulation rates and the completeness of stratigraphic sections, Journal of Geology, 89, 569-584, 1981. Sun, Y., Joachimski, M. M., Wignall, P. B., Yan, C., Chen, Y., Jiang, H., Wang, L., and Lai, X.: Lethally hot temperatures during the Early Triassic greenhouse, Science, 338, 366-370, 2012.

The Handling of Hazard Data on a National Scale: A Case Study from the British Geological Survey

NASA Astrophysics Data System (ADS)

Royse, Katherine R.

2011-11-01

This paper reviews how hazard data and geological map data have been combined by the British Geological Survey (BGS) to produce a set of GIS-based national-scale hazard susceptibility maps for the UK. This work has been carried out over the last 9 years and as such reflects the combined outputs of a large number of researchers at BGS. The paper details the inception of these datasets from the development of the seamless digital geological map in 2001 through to the deterministic 2D hazard models produced today. These datasets currently include landslides, shrink-swell, soluble rocks, compressible and collapsible deposits, groundwater flooding, geological indicators of flooding, radon potential and potentially harmful elements in soil. These models have been created using a combination of expert knowledge (from both within BGS and from outside bodies such as the Health Protection Agency), national databases (which contain data collected over the past 175 years), multi-criteria analysis within geographical information systems and a flexible rule-based approach for each individual geohazard. By using GIS in this way, it has been possible to model the distribution and degree of geohazards across the whole of Britain.

The effects of geology and the impact of seasonal correction factors on indoor radon levels: a case study approach.

PubMed

Gillmore, Gavin K; Phillips, Paul S; Denman, Antony R

2005-01-01

Geology has been highlighted by a number of authors as a key factor in high indoor radon levels. In the light of this, this study examines the application of seasonal correction factors to indoor radon concentrations in the UK. This practice is based on an extensive database gathered by the National Radiological Protection Board over the years (small-scale surveys began in 1976 and continued with a larger scale survey in 1988) and reflects well known seasonal variations observed in indoor radon levels. However, due to the complexity of underlying geology (the UK arguably has the world's most complex solid and surficial geology over the shortest distances) and considerable variations in permeability of underlying materials it is clear that there are a significant number of occurrences where the application of a seasonal correction factor may give rise to over-estimated or under-estimated radon levels. Therefore, the practice of applying a seasonal correction should be one that is undertaken with caution, or not at all. This work is based on case studies taken from the Northamptonshire region and comparisons made to other permeable geologies in the UK.

Geologic map of the Middletown quadrangle, Frederick, Shenandoah, and Warren Counties, Virginia

USGS Publications Warehouse

Orndorff, Randall C.; Epstein, Jack Burton; McDowell, Robert C.

1999-01-01

The Middletown 1:24,000-scale quadrangle is one of several quadrangles in Frederick County, Virginia mapped or being mapped by geologists from the U.S. Geological Survey in Reston, VA with funding from the National Cooperative Geologic Mapping Program. This map was originally published as a paper product in 1999. It has been converted to GIS-based digital form. This work is part of a project being lead by the U.S. Geological Survey Water Resources Discipline, Virginia District, to investigate the geologic framework and groundwater resources of Frederick County as well as other areas in the northern Shenandoah Valley of Virginia and West Virginia. For more information about the Project see: http://geology.er.usgs.gov/eespteam/Karst/index.html for Geologic Discipline efforts and http://va.water.usgs.gov/va134/index.htm for Water Resources Discipline efforts.

Toward a continuous 405-kyr-calibrated Astronomical Time Scale for the Mesozoic Era

NASA Astrophysics Data System (ADS)

Hinnov, Linda; Ogg, James; Huang, Chunju

2010-05-01

Mesozoic cyclostratigraphy is being assembled into a continuous Astronomical Time Scale (ATS) tied to the Earth's cyclic orbital parameters. Recognition of a nearly ubiquitous, dominant ~400-kyr cycling in formations throughout the era has been particularly striking. Composite formations spanning contiguous intervals up to 50 myr clearly express these long-eccentricity cycles, and in some cases, this cycling is defined by third- or fourth-order sea-level sequences. This frequency is associated with the 405-kyr orbital eccentricity cycle, which provides a basic metronome and enables the extension of the well-defined Cenozoic ATS to scale the majority of the Mesozoic Era. This astronomical calibration has a resolution comparable to the 1% to 0.1% precision for radioisotope dating of Mesozoic ash beds, but with the added benefit of providing continuous stratigraphic coverage between dated beds. Extended portions of the Mesozoic ATS provide solutions to long-standing geologic problems of tectonics, eustasy, paleoclimate change, and rates of seafloor spreading.

Interpretive geologic bedrock map of the Tanana B-1 Quadrangle, Central Alaska

USGS Publications Warehouse

Reifenstuh, Rocky R.; Dover, James H.; Newberry, Rainer J.; Calutice, Karen H.; Liss, Shirley A.; Blodgett, Robert B.; Budtzen, Thomas K.; Weber, Florence R.

1997-01-01

This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes detailed bedrock, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.

Identification of Geostructures of continental crust, particularly as they relate to mineral-resource evaluation

NASA Technical Reports Server (NTRS)

Gryc, G. (Principal Investigator); Lathram, E. H.

1973-01-01

The author has identified the following significant results. Analysis of lineated lakes in the Umiat, Alaska area and comparison with known geology, gravity, and magnetic data in the the area suggest concealed structures exist at depth, possibly at or near basement, which may represent targets for petroleum exploration. Compilation of reconnaissance geologic data on 1:250,000 scale enlargements of ERTS-1 images near Corwin reveal structural and stratigraphic anomalies that suggest the Cretaceous sequence is less thick than supposed and is repeated in a series of plates superimposed by flat thrust faults. The structural style differs from that in coeval strata to the northeast, across the northwest-trending linear zone separating differing tectonic styles in older strata noted earlier. The regional extension of a fault known locally in the McCarthy area has been recognized; this fault appears to form the boundary of a significant terrane of mid-Paleozoic metamorphic rocks. ERTS-1 images are being used operationally, at 1:1,000,000 scale in the compilation of regional geologic maps, and at 1:250,000 scale in field mapping in the Brooks Range, in the study of faults in seismically active southern Alaska, in field-checking interpretations previously made from ERTS-1 imagery, and orthophoto base maps for geologic maps.

Hands-On Exercise in Environmental Structural Geology Using a Fracture Block Model.

ERIC Educational Resources Information Center

Gates, Alexander E.

2001-01-01

Describes the use of a scale analog model of an actual fractured rock reservoir to replace paper copies of fracture maps in the structural geology curriculum. Discusses the merits of the model in enabling students to gain experience performing standard structural analyses. (DDR)

Geological Modeling and Fluid Flow Simulation of Acid Gas Storage, Nugget Sandstone, Moxa Arch, Wyoming

NASA Astrophysics Data System (ADS)

Li, S.; Zhang, Y.; Zhang, X.; Du, C.

2009-12-01

The Moxa Arch Anticline is a regional-scale northwest-trending uplift in western Wyoming where geological storage of acid gases (CO2, CH4, N2, H2S, He) from ExxonMobile's Shute Creek Gas Plant is under consideration. The Nugget Sandstone, a deep saline aquifer at depths exceeding 17,170 ft, is a candidate formation for acid gas storage. As part of a larger goal of determining site suitability, this study builds three-dimensional local to regional scale geological and fluid flow models for the Nugget Sandstone, its caprock (Twin Creek Limestone), and an underlying aquifer (Ankareh Sandstone), or together, the ``Nugget Suite''. For an area of 3000 square miles, geological and engineering data were assembled, screened for accuracy, and digitized, covering an average formation thickness of ~1700 feet. The data include 900 public-domain well logs (SP, Gamma Ray, Neutron Porosity, Density, Sonic, shallow and deep Resistivity, Lithology, Deviated well logs), 784 feet of core measurements (porosity and permeability), 4 regional geological cross sections, and 3 isopach maps. Data were interpreted and correlated for geological formations and facies, the later categorized using both Neural Network and Gaussian Hierarchical Clustering algorithms. Well log porosities were calibrated with core measurements, those of permeability estimated using formation-specific porosity-permeability transforms. Using conditional geostatistical simulations (first indicator simulation of facies, then sequential Gaussian simulation of facies-specific porosity), data were integrated at the regional-scale to create a geological model from which a local-scale simulation model surrounding the Shute Creek injection site was extracted. Based on this model, full compositional multiphase flow simulations were conducted with which we explore (1) an appropriate grid resolution for accurate acid gas predictions (pressure, saturation, and mass balance); (2) sensitivity of key geological and engineering variables on model predictions. Results suggest that (1) a horizontal and vertical resolution of 1/75 and 1/5~1/2 porosity correlation length is needed, respectively, to accurately capture the flow physics and mass balance. (2) the most sensitive variables that have first order impact on model predictions (i.e., regional storage, local displacement efficiency) are boundary condition, vertical permeability, relative permeability hysteresis, and injection rate. However, all else being equal, formation brine salinity has the most important effects on the concentrations of all dissolved components. Future work will define and simulate reactions of acid gases with formation brines and rocks which are currently under laboratory investigations.

OneGeology-Europe and the new EC Directive INSPIRE - A matter of semantic subtlety?

NASA Astrophysics Data System (ADS)

Asch, K.

2009-04-01

The EC INSPIRE Directive which came into force in May 2007 set out how the Member States of the European Union would describe, discover and provide access to spatial environmental data in a harmonised way. Amongst the data sets specified in INSPIRE is geology. A fundamental question is just what is meant by ‘geology'? The question must be answered, and in some detail, if the intentions of the INSPIRE Directive to provide consistency of access are to be realised The Directive itself provides very little constraint on this definition. In it geology is described as "Geology characterised according to composition and structure. Includes bedrock, aquifers and geomorphology". The challenge for the EC and its Member States - more specifically for the geological survey community - is to convert this single line into a precise and practical specification that will deliver the outcomes intended by INSPIRE. The geological survey community is attempting to develop this specification through two complementary routes. Theme Working Groups - a generic procedure adopted by the EC that will start in May 2009 - and a new EC eContentplus project, OneGeology-Europe. Within OneGeology-Europe is a Work Package whose task is to deliver a semantic specification of "geology" at 1:1 million scale. While the initial reaction of some would be to question whether defining geology at this scale poses any significant challenges the reality is somewhat different. Fundamental questionsare: Should we specify the geology at the surface or restrict it to "bedrock" geology? Do we attempt to define the rocks chronostratigraphically, or by their lithology, perhaps even by the more regional lithostratigraphy or by genetic aspect? To what extent do we include tectonic features? How to cope with th ecomplexity of metamorphic rocks etc? These are only some of the high level questions - the devil, however, comes in the detail. How should we deal with the classification of the Pre-Cambrian rocks? What approach should we adopt to hypabyssal rocks? There are many more to approach and of course already existing vocabulararies, definitions and classifications need to be taken into account. Compounding these questions is the fact that in the absence of accepted international standards, almost every national geological survey has adopted different standards; standards which they are reluctant to concede. This presentation will outline the issues and challenges facing the geological community to define the geological classification of the OneGeology-Europe project while considering the future requirements of the EC INSPIRE Directive and provides an update on the progress in meeting those challenges.

Multi-scale variability and long-range memory in indoor Radon concentrations from Coimbra, Portugal

NASA Astrophysics Data System (ADS)

Donner, Reik V.; Potirakis, Stelios; Barbosa, Susana

2014-05-01

The presence or absence of long-range correlations in the variations of indoor Radon concentrations has recently attracted considerable interest. As a radioactive gas naturally emitted from the ground in certain geological settings, understanding environmental factors controlling Radon concentrations and their dynamics is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we re-analyze two high-resolution records of indoor Radon concentrations from Coimbra, Portugal, each of which spans several months of continuous measurements. In order to evaluate the presence of long-range correlations and fractal scaling, we utilize a multiplicity of complementary methods, including power spectral analysis, ARFIMA modeling, classical and multi-fractal detrended fluctuation analysis, and two different estimators of the signals' fractal dimensions. Power spectra and fluctuation functions reveal some complex behavior with qualitatively different properties on different time-scales: white noise in the high-frequency part, indications of some long-range correlated process dominating time scales of several hours to days, and pronounced low-frequency variability associated with tidal and/or meteorological forcing. In order to further decompose these different scales of variability, we apply two different approaches. On the one hand, applying multi-resolution analysis based on the discrete wavelet transform allows separately studying contributions on different time scales and characterize their specific correlation and scaling properties. On the other hand, singular system analysis (SSA) provides a reconstruction of the essential modes of variability. Specifically, by considering only the first leading SSA modes, we achieve an efficient de-noising of our environmental signals, highlighting the low-frequency variations together with some distinct scaling on sub-daily time-scales resembling the properties of a long-range correlated process.

Image Analysis for Facility Siting: a Comparison of Lowand High-altitude Image Interpretability for Land Use/land Cover Mapping

NASA Technical Reports Server (NTRS)

Borella, H. M.; Estes, J. E.; Ezra, C. E.; Scepan, J.; Tinney, L. R.

1982-01-01

For two test sites in Pennsylvania the interpretability of commercially acquired low-altitude and existing high-altitude aerial photography are documented in terms of time, costs, and accuracy for Anderson Level II land use/land cover mapping. Information extracted from the imagery is to be used in the evaluation process for siting energy facilities. Land use/land cover maps were drawn at 1:24,000 scale using commercially flown color infrared photography obtained from the United States Geological Surveys' EROS Data Center. Detailed accuracy assessment of the maps generated by manual image analysis was accomplished employing a stratified unaligned adequate class representation. Both 'area-weighted' and 'by-class' accuracies were documented and field-verified. A discrepancy map was also drawn to illustrate differences in classifications between the two map scales. Results show that the 1:24,000 scale map set was more accurate (99% to 94% area-weighted) than the 1:62,500 scale set, especially when sampled by class (96% to 66%). The 1:24,000 scale maps were also more time-consuming and costly to produce, due mainly to higher image acquisition costs.

Remote sensing and GIS-based prediction and assessment of copper-gold resources in Thailand

NASA Astrophysics Data System (ADS)

Yang, Shasha; Wang, Gongwen; Du, Wenhui; Huang, Luxiong

2014-03-01

Quantitative integration of geological information is a frontier and hotspot of prospecting decision research in the world. The forming process of large scale Cu-Au deposits is influenced by complicated geological events and restricted by various geological factors (stratum, structure and alteration). In this paper, using Thailand's copper-gold deposit district as a case study, geological anomaly theory is used along with the typical copper and gold metallogenic model, ETM+ remote sensing images, geological maps and mineral geology database in study area are combined with GIS technique. These techniques create ore-forming information such as geological information (strata, line-ring faults, intrusion), remote sensing information (hydroxyl alteration, iron alteration, linear-ring structure) and the Cu-Au prospect targets. These targets were identified using weights of evidence model. The research results show that the remote sensing and geological data can be combined to quickly predict and assess for exploration of mineral resources in a regional metallogenic belt.

DEVELOPMENT OF RIPARIAN ZONE INDICATORS (INT. GRANT)

EPA Science Inventory

Landscape features (e.g., land use) influence water quality characteristics on a variety of spatial scales. For example, while land use is controlled by anthropogenic features at a local scale, geologic features are set at larger spatial, and longer temporal scales. Individual ...

Three-Dimensional Geologic Map of the Hayward Fault Zone, San Francisco Bay Region, California

USGS Publications Warehouse

Phelps, G.A.; Graymer, R.W.; Jachens, R.C.; Ponce, D.A.; Simpson, R.W.; Wentworth, C.M.

2008-01-01

A three-dimensional (3D) geologic map of the Hayward Fault zone was created by integrating the results from geologic mapping, potential field geophysics, and seismology investigations. The map volume is 100 km long, 20 km wide, and extends to a depth of 12 km below sea level. The map volume is oriented northwest and is approximately bisected by the Hayward Fault. The complex geologic structure of the region makes it difficult to trace many geologic units into the subsurface. Therefore, the map units are generalized from 1:24,000-scale geologic maps. Descriptions of geologic units and structures are offered, along with a discussion of the methods used to map them and incorporate them into the 3D geologic map. The map spatial database and associated viewing software are provided. Elements of the map, such as individual fault surfaces, are also provided in a non-proprietary format so that the user can access the map via open-source software. The sheet accompanying this manuscript shows views taken from the 3D geologic map for the user to access. The 3D geologic map is designed as a multi-purpose resource for further geologic investigations and process modeling.

Geological modeling of submeter scale heterogeneity and its influence on tracer transport in a fluvial aquifer

NASA Astrophysics Data System (ADS)

Ronayne, Michael J.; Gorelick, Steven M.; Zheng, Chunmiao

2010-10-01

We developed a new model of aquifer heterogeneity to analyze data from a single-well injection-withdrawal tracer test conducted at the Macrodispersion Experiment (MADE) site on the Columbus Air Force Base in Mississippi (USA). The physical heterogeneity model is a hybrid that combines 3-D lithofacies to represent submeter scale, highly connected channels within a background matrix based on a correlated multivariate Gaussian hydraulic conductivity field. The modeled aquifer architecture is informed by a variety of field data, including geologic core sampling. Geostatistical properties of this hybrid heterogeneity model are consistent with the statistics of the hydraulic conductivity data set based on extensive borehole flowmeter testing at the MADE site. The representation of detailed, small-scale geologic heterogeneity allows for explicit simulation of local preferential flow and slow advection, processes that explain the complex tracer response from the injection-withdrawal test. Based on the new heterogeneity model, advective-dispersive transport reproduces key characteristics of the observed tracer recovery curve, including a delayed concentration peak and a low-concentration tail. Importantly, our results suggest that intrafacies heterogeneity is responsible for local-scale mass transfer.

Advances in Planetary Geology

NASA Technical Reports Server (NTRS)

Grant, John A., III; Nedell, Susan S.

1987-01-01

The surface of Mars displays a broad range of channel and valley features. There is as great a range in morphology as in scale. Some of the features of Martian geography are examined. Geomorphic mapping, crater counts on selected surfaces, and a detailed study of drainage basins are used to trace the geologic evolution of the Margaritifer Sinus Quandrangle. The layered deposits in the Valles Marineris are described in detail and the geologic processes that could have led to their formation are analyzed.

Managing Disaster in the Ionian Sea: Planning and Optimizing Logistics for Disaster Relief Operations for the Island of Kefalonia

DTIC Science & Technology

2010-06-01

surface directly (vertically) above the hypocenter (United States Geological Survey , 2009). A graphical depiction of epicenter and hypocenter appears...to their focal depth: shallow (70-300 km), intermediate (70-300 km), and deep (300-700 km) (United States Geological Survey , 1989a). The concepts of...magnitude (Mb), and moment magnitude (MW) scales (Papazachos & Papazachou, 2003, p. 39; United States Geological Survey , 2009c). All these measurement

Geologic Map of the Atlin Quadrangle, Southeastern Alaska

USGS Publications Warehouse

Brew, David A.; Himmelberg, Glen R.; Ford, Arthur B.

2009-01-01

This map presents the results of U.S. Geological Survey (USGS) geologic bedrock mapping studies in the mostly glacier covered Atlin 1:250,000-scale quadrangle, northern southeastern Alaska. These studies are part of a long-term systematic effort by the USGS to provide bedrock geologic and mineral-resource information for all of southeastern Alaska, covering all of the Tongass National Forest (including Wilderness Areas) and Glacier Bay National Park and Preserve. Some contributions to this effort are those concerned with southwesternmost part of the region, the Craig and Dixon Entrance quadrangles (Brew, 1994; 1996) and with the Wrangell-Petersburg area (Brew, 1997a-m; Brew and Grybeck, 1997; Brew and Koch, 1997). As shown on the index map (fig. 1), the study area is almost entirely in the northern Coast Mountains adjacent to British Columbia, Canada. No previous geologic map has been published for the area, although Brew and Ford (1985) included a small part of it in a preliminary compilation of the adjoining Juneau quadrangle; and Brew and others (1991a) showed the geology at 1:500,000 scale. Areas mapped nearby in British Columbia and the United States are also shown on figure 1. All of the map area is in the Coast Mountains Complex as defined by Brew and others (1995a). A comprehensive bibliography is available for this and adjacent areas (Brew, 1997n).

Geosites and geoheritage representations - a cartographic approach

NASA Astrophysics Data System (ADS)

Rocha, Joao; Brilha, José

2016-04-01

In recent years, the increasing awareness of the importance of nature conservation, particularly towards the protection, conservation and promotion of geological sites, has resulted in a wide range of scientific studies. In a certain way, the majority of geodiversity studies, geoconservation strategies and geosites inventories and geoheritage assessment projects will use, on a particular stage, a cartographic representation - a map - of the most relevant geological and geomorphological features within the area of analyses. A wide range of geosite maps and geological heritage maps have been produced but, so far, a widely accepted conceptual cartographic framework with a specific symbology for cartographic representation has not been created. In this work we debate the lack of a systematic and conceptual framework to support geoheritage and geosite mapping. It is important to create a widely accepted conceptual cartographic framework with a specific symbology to be used within maps dedicated to geoheritage and geosites. We propose a cartographic approach aiming the conceptualization and the definition of a nomenclature and symbology system to be used on both geosite and geoheritage maps. We define a symbology framework for geosite and geoheritage mapping addressed to general public and to secondary school students, in order to be used as geotouristic and didactic tools, respectively. Three different approaches to support the definition of the symbology framework were developed: i) symbols to correlate geosites with the geological time scale; ii) symbols related to each one of the 27 geological frameworks defined in the Portuguese geoheritage inventory; iii) symbols to represent groups of geosites that share common geological and geomorphological features. The use of these different symbols in a map allows a quick understanding of a set of relevant information, in addition to the usual geographical distribution of geosites in a certain area.

A paleolatitude approach to assessing surface temperature history for use in burial heating models

USGS Publications Warehouse

Barker, Charles E.

2000-01-01

Calculations using heat flow theory as well as case histories show that over geologic time scales (106 years), changes in mean annual surface temperature (Ts) on the order of 10°C penetrate kilometers deep into the crust. Thus, burial heating models of sedimentary basins, which typically span kilometers in depth and persist over geological time frames, should consider Ts history to increase their accuracy. In any case, Ts history becomes important when it changes enough to be detected by a thermal maturation index like vitrinite reflectance, a parameter widely used to constrain burial heating models. Assessment of the general temperature conditions leading to petroleum generation indicates that changes in Ts as small as 6°C can be detected by vitrinite reflectance measurements. This low temperature threshold indicates that oil and gas windows can be significantly influenced by Ts history. A review of paleoclimatic factors suggests the significant and geologically resolvable factors affecting Ts history are paleolatitude, long-term changes between cool and warm geological periods (climate mode), the degree to which a basin is removed from the sea (geographic isolation), and elevation or depth relative to sea level. Case studies using geologically realistic data ranges or different methods of estimating Ts in a burial heating model indicate a significant impact of Ts when: (1) continental drift, subduction, tectonism and erosion significantly change paleolatitude, paleoaltitude, or paleogeography; (2) strata are at, or near, maximum burial, and changes in Ts directly influence maximum burial temperature; and (3), when a significant change in Ts occurs near the opening or closing of the oil or gas windows causing petroleum generation to begin or cease. Case studies show that during the burial heating and petroleum generation phase of basin development changes in climate mode alone can influence Ts by about 15°C. At present, Ts changes from the poles to the equator by about 50°C. Thus, in extreme cases, continental drift alone can seemingly produce Ts changes on the order of 50°C over a time frame of 107 years.

Time-scale calibration by U-Pb geochronology: Examples from the Triassic Period

NASA Astrophysics Data System (ADS)

Mundil, R.

2009-05-01

U-Pb zircon geochronology, pioneered by Tom Krogh, is a cornerstone for the calibration of the time scale. Before Krogh's innovations, U-Pb geochronology was essentially limited by laboratory blank Pb (typically hundreds of nanograms) inherent in the then existing zircon dissolution and purification methods. The introduction of high pressure HF dissolution combined with miniature ion exchange columns (1) reduced the blank by orders of magnitude and allowed mass-spectrometric analyses of minute amounts of material (picograms of Pb and U). Krogh also recognized the need for minimizing the effects of Pb loss, and the introduction of the air-abrasion technique was the method of choice for two decades (2), until the development of the combined annealing and chemical abrasion technique resulted in essentially closed system zircons (3). These are the prerequisite for obtaining precise (permil-level) and accurate radio-isotopic ages of individual zircons contained in primary volcanic ash deposits, which are primary targets for the calibration of the time scale if they occur within fossil bearing sediments. A prime example is the calibration of the Triassic time scale which improved significantly using these techniques. The ages for the base and the top of the Triassic are constrained by U-Pb ages to 252.3 (4) and 201.5 Ma (5), respectively. These dates also constrain the ages of major extinction events at the Permian-Triassic and Triassic-Jurassic boundaries, and are statistically indistinguishable from ages obtained for the Siberian Traps and volcanic products from the Central Atlantic Magmatic Province, respectively, suggesting a causal link. Ages for these continental volcanics, however, are mostly from the K-Ar (40Ar/39Ar) system which requires accounting and correcting for a systematic bias of ca 1 % between U-Pb and 40Ar/39Ar isotopic ages (the 40Ar/39Ar ages being younger) (6). Robust U-Pb age constraints also exist for the Induan- Olenekian boundary (251.2 Ma, (7)) and the Early-Middle Triassic (Olenekian-Anisian) boundary (247.2 Ma, (8, 9)), resulting in a surprisingly short duration of the Early Triassic which has implications for the timing of biotic recovery and major changes in ocean chemistry during this time. Furthermore, the Anisian-Ladinian boundary is constrained to 242.0 Ma by new U-Pb and 40Ar/39Ar ages. Radio-isotopic ages for the Late Triassic are scarce and the only reliable and biostratigraphically controlled age is from an upper Carnian tuff dated to 230.9 Ma (10), yielding a duration of more than 35 Ma for the Late Triassic. The resulting time-scale is at odds with the most recent compilation (11) but arguably more accurate because it is entirely based on U-Pb analyses applied to closed-system zircons with uncertainties at the permil level or better. 1. T. E. Krogh, Geochimica et Cosmochimica Acta 37, 485 (1973); 2. T. E. Krogh, Geochimica et Cosmochimica Acta 46, 637 (1982); 3. J. M. Mattinson, Chemical Geology 220, 47 (2005); 4. R. Mundil, K. R. Ludwig, I. Metcalfe, P. R. Renne, Science 305, 1760 (2004); 5. U. Schaltegger, J. Guex, A. Bartolini, B. Schoene, M. Ovtcharova, Earth and Planetary Science Letters 267, 266 (2008); 6. R. Mundil, P. R. Renne, K. K. Min, K. R. Ludwig, in Eos Trans. AGU, Fall Meet. Suppl. (2006), vol. 87(52), pp. V21A-0543; 7. T. Galfetti et al., Earth and Planetary Science Letters 258, 593 (2007). 8. M. Ovtcharova et al., Earth and Planetary Science Letters 243, 463 (2006). 9. J. Ramezani et al., Earth and Planetary Science Letters 256, 244 (2007). 10. S. Furin et al., Geology 34, 1009 (2006); 11. J. G. Ogg, in A Geologic Time Scale 2004 F. M. Gradstein, J. G. Ogg, A. G. Smith, Eds. (University Press, Cambridge, 2004) pp. 271-306.

Geo-Engineering through Internet Informatics (GEMINI)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watney, W. Lynn; Doveton, John H.; Victorine, John R.

GEMINI will resolve reservoir parameters that control well performance; characterize subtle reservoir properties important in understanding and modeling hydrocarbon pore volume and fluid flow; expedite recognition of bypassed, subtle, and complex oil and gas reservoirs at regional and local scale; differentiate commingled reservoirs; build integrated geologic and engineering model based on real-time, iterate solutions to evaluate reservoir management options for improved recovery; provide practical tools to assist the geoscientist, engineer, and petroleum operator in making their tasks more efficient and effective; enable evaluations to be made at different scales, ranging from individual well, through lease, field, to play and regionmore » (scalable information infrastructure); and provide training and technology transfer to evaluate capabilities of the client.« less

My Pet Rock

ERIC Educational Resources Information Center

Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

2008-01-01

Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

Publications - MP 126 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

DGGS MP 126 Publication Details Title: 400 MHz ground-penetrating radar, Itkillik River, North Slope , Itkillik River, North Slope, Alaska: Alaska Division of Geological & Geophysical Surveys Miscellaneous , North Slope, Alaska, scale 1:100 (8.6 M) Keywords Fluvial; Ground-Penetrating Radar; Itkillik River

Evaluating a Geology Curriculum for Non-Majors.

ERIC Educational Resources Information Center

Boone, William J.

Two key factors affecting the success of non-major science courses are students' perceptions of topic difficulty and interest. An attitudinal survey administered to 300 college students, after completion of a college science course, evaluated their attitudes toward a geology curriculum. Using a Likert type scale students rated their level of…

Simulation of Anisotropic Rock Damage for Geologic Fracturing

NASA Astrophysics Data System (ADS)

Busetti, S.; Xu, H.; Arson, C. F.

2014-12-01

A continuum damage model for differential stress-induced anisotropic crack formation and stiffness degradation is used to study geologic fracturing in rocks. The finite element-based model solves for deformation in the quasi-linear elastic domain and determines the six component damage tensor at each deformation increment. The model permits an isotropic or anisotropic intact or pre-damaged reference state, and the elasticity tensor evolves depending on the stress path. The damage variable, similar to Oda's fabric tensor, grows when the surface energy dissipated by three-dimensional opened cracks exceeds a threshold defined at the appropriate scale of the representative elementary volume (REV). At the laboratory or wellbore scale (<1m) brittle continuum damage reflects microcracking, grain boundary separation, grain crushing, or fine delamination, such as in shale. At outcrop (1m-100m), seismic (10m-1000m), and tectonic (>1000m) scales the damaged REV reflects early natural fracturing (background or tectonic fracturing) or shear strain localization (fault process zone, fault-tip damage, etc.). The numerical model was recently benchmarked against triaxial stress-strain data from laboratory rock mechanics tests. However, the utility of the model to predict geologic fabric such as natural fracturing in hydrocarbon reservoirs was not fully explored. To test the ability of the model to predict geological fracturing, finite element simulations (Abaqus) of common geologic scenarios with known fracture patterns (borehole pressurization, folding, faulting) are simulated and the modeled damage tensor is compared against physical fracture observations. Simulated damage anisotropy is similar to that derived using fractured rock-mass upscaling techniques for pre-determined fracture patterns. This suggests that if model parameters are constrained with local data (e.g., lab, wellbore, or reservoir domain), forward modeling could be used to predict mechanical fabric at the relevant REV scale. This reference fabric also can be used as the starting material property to pre-condition subsequent deformation or fluid flow. Continuing efforts are to expand the present damage model to couple damage evolution with plasticity and with permeability for more geologically realistic simulation.

Upscaling of reaction rates in reactive transport using pore-scale reactive transport model

NASA Astrophysics Data System (ADS)

Yoon, H.; Dewers, T. A.; Arnold, B. W.; Major, J. R.; Eichhubl, P.; Srinivasan, S.

2013-12-01

Dissolved CO2 during geological CO2 storage may react with minerals in fractured rocks, confined aquifers, or faults, resulting in mineral precipitation and dissolution. The overall rate of reaction can be affected by coupled processes among hydrodynamics, transport, and reactions at the (sub) pore-scale. In this research pore-scale modeling of coupled fluid flow, reactive transport, and heterogeneous reaction at the mineral surface is applied to account for permeability alterations caused by precipitation-induced pore-blocking. This work is motivated by the observed CO2 seeps from a natural analog to geologic CO2 sequestration at Crystal Geyser, Utah. A key observation is the lateral migration of CO2 seep sites at a scale of ~ 100 meters over time. A pore-scale model provides fundamental mechanistic explanations of how calcite precipitation alters flow paths by pore plugging under different geochemical compositions and pore configurations. In addition, response function of reaction rates will be constructed from pore-scale simulations which account for a range of reaction regimes characterized by the Damkohler and Peclet numbers. Newly developed response functions will be used in a continuum scale model that may account for large-scale phenomena mimicking lateral migration of surface CO2 seeps. Comparison of field observations and simulations results will provide mechanistic explanations of the lateral migration and enhance our understanding of subsurface processes associated with the CO2 injection. This work is supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Click-On-Diagram Questions: a New Tool to Study Conceptions Using Classroom Response Systems

NASA Astrophysics Data System (ADS)

LaDue, Nicole D.; Shipley, Thomas F.

2018-06-01

Geoscience instructors depend upon photos, diagrams, and other visualizations to depict geologic structures and processes that occur over a wide range of temporal and spatial scales. This proof-of-concept study tests click-on-diagram (COD) questions, administered using a classroom response system (CRS), as a research tool for identifying spatial misconceptions. First, we propose a categorization of spatial conceptions associated with geoscience concepts. Second, we implemented the COD questions in an undergraduate introductory geology course. Each question was implemented three times: pre-instruction, post-instruction, and at the end of the course to evaluate the stability of students' conceptual understanding. We classified each instance as (1) a false belief that was easily remediated, (2) a flawed mental model that was not fully transformed, or (3) a robust misconception that persisted despite targeted instruction. Geographic Information System (GIS) software facilitated spatial analysis of students' answers. The COD data confirmed known misconceptions about Earth's structure, geologic time, and base level and revealed a novel robust misconception about hot spot formation. Questions with complex spatial attributes were less likely to change following instruction and more likely to be classified as a robust misconception. COD questions provided efficient access to students' conceptual understanding. CRS-administered COD questions present an opportunity to gather spatial conceptions with large groups of students, immediately, building the knowledge base about students' misconceptions and providing feedback to guide instruction.

Mid-Atlantic multichannel seismic-reflection profiles 14, 15, 16, and 17

USGS Publications Warehouse

Schlee, John Stevens

1980-01-01

The U. S. Geological Survey (USGS) is making available four multi­channel profiles collected by Teledyne Exploration in 1977 by means of a 48-channel streamer (3600 m long) and four airguns (2160 in). Profiles 15 and 16 were processed by.Teledyne Exploration and profiles 14 and 17 were processed on the Phoenix "I"* computer·by the USGS. The processing included standard demultiplexing, deconvolution before and aftfer stack, Common Depth Point (CDP) gathers, velocity analyses every 3 km, move-out correction, stacking, time-variant, filtering, and time-variant scaling.The released lines are over the outer edge of the Continental Shelf in the northern part of the Baltimore Canyon trough (Line 14: 140 km long and Line 15: 157 km long), over the Long Island platform. (Line 16: 313 km long), and over the Carolina platform (Line 17: 186 km long). These profiles were collected as a part of a regional grid over offshore Atlantic sedimentary basins in a continuing program to assess the resource potential by means of nonproprietary data.These profiles, plus the velocity scans and shotpoint maps, may be viewed at U. S. Geological Survey, Quissett Campus, Woods Hole, MA. 02543, and U. S. Geological Survey, Bldg. 25, Denver Federal Center, Denver, CO. Copies of maps, scans, and profiles can be purchased only from the National Geophysical Solar-Terrestrial Data Center, Environmental Data Service (NOM), Code D 621, Boulder, CO 80302.

Environmental aspects of engineering geological mapping in the United States

USGS Publications Warehouse

Radbruch-Hall, Dorothy H.

1979-01-01

Many engineering geological maps at different scales have been prepared for various engineering and environmental purposes in regions of diverse geological conditions in the United States. They include maps of individual geological hazards and maps showing the effect of land development on the environment. An approach to assessing the environmental impact of land development that is used increasingly in the United States is the study of a single area by scientists from several disciplines, including geology. A study of this type has been made for the National Petroleum Reserve in northern Alaska. In the San Francisco Bay area, a technique has been worked out for evaluating the cost of different types of construction and land development in terms of the cost of a number of kinds of earth science factors. ?? 1979 International Association of Engineering Geology.

TRENDS IN ENGINEERING GEOLOGIC AND RELATED MAPPING.

USGS Publications Warehouse

Varnes, David J.; Keaton, Jeffrey R.

1983-01-01

Progress is reviewed that has been made during the period 1972-1982 in producing medium- and small-scale engineering geologic maps with a variety of content. Improved methods to obtain and present information are evolving. Standards concerning text and map content, soil and rock classification, and map symbols have been proposed. Application of geomorphological techniques in terrain evaluation has increased, as has the use of aerial photography and other remote sensing. Computers are being used to store, analyze, retrieve, and print both text and map information. Development of offshore resources, especially petroleum, has led to marked improvement and growth in marine engineering geology and geotechnology. Coordinated planning for societal needs has required broader scope and increased complexity of both engineering geologic and environmental geologic studies. Refs.