Note: This page contains sample records for the topic geology wall-rock alteration from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

Mass transfer during wall-rock alteration: An example from a quartz-graphite vein, Black Hills, South Dakota  

SciTech Connect

Mass transfer and fluid-rock interaction have been evaluated along two sample traverses in low-sillimanite grade quartz-mica schist adjacent to a synmetamorphic quartz-graphite vein in the southern Black Hills, South Dakota. In an {approximately}17 cm halo between apparently unaltered schist and the vein contact is an outer zone of cryptic alteration and three inner zones of visible alteration. The cryptic zone consists of the original prograde metamorphic mineral assemblage plus anomalously high amounts of tourmaline. The outermost visible zone contains abundant graphite. The second visible zone is defined by intensive bleaching of the schist. The innermost visible zone, immediately adjacent to the vein, is tourmaline + quartz + plagioclase + limonite + graphite. The vein is composed almost entirely of quartz, but also contains trace amounts of graphite. Mass balance calculations indicate that Al was essentially inert. The predominant chemical changes during wall-rock alteration were addition of B and C from the vein-forming fluid along with loss of K from the wall rocks, corresponding to precipitation of tourmaline and graphite, and the progressive destruction of microcline, biotite, and muscovite toward the vein. In addition, the elements V, Cr, Cu, Zn, Pb, As, Sb, W, and Au were introduced into the country rock, whereas Si, Rb, Ba, and Cs were removed. Fluid-rock interaction modeling suggests that between one and four equivalent masses of fluid interacted chemically with the most altered mineral assemblages. In addition, greater than one equivalent mass of reactive fluid penetrated to distances of at least 5 cm from the vein contact.

Galbreath, K.C.; Duke, E.F.; Papike, J.J. (South Dakota School of Mines and Technology, Rapid City, SD (USA)); Laul, J.C. (Pacific Northwest Laboratories, Richland, WA (USA))

1988-07-01

2

Mount St. Augustine volcano fumarole wall rock alteration: mineralogy, zoning, composition and numerical models of its formation process  

NASA Astrophysics Data System (ADS)

Intensely altered wall rock was collected from high-temperature (640 °C) and low-temperature (375 °C) vents at Augustine volcano in July 1989. The high-temperature altered rock exhibits distinct mineral zoning differentiated by color bands. In order of decreasing temperature, the color bands and their mineral assemblages are: (a) white to grey (tridymite-anhydrite); (b) pink to red (tridymite-hematite-Fe hydroxide-molysite (FeCl 3) with minor amounts of anhydrite and halite); and (c) dark green to green (anhydrite-halite-sylvite-tridymite with minor amounts of molysite, soda and potash alum, and other sodium and potassium sulfates). The alteration products around the low-temperature vents are dominantly cristobalite and amorphous silica with minor potash and soda alum, aphthitalite, alunogen and anhydrite. Compared to fresh 1986 Augustine lava, the altered rocks exhibit enrichments in silica, base metals, halogens and sulfur and show very strong depletions in Al in all alteration zones and in iron, alkali and alkaline earth elements in some of the alteration zones. To help understand the origins of the mineral assemblages in altered Augustine rocks, we applied the thermochemical modeling program, GASWORKS, in calculations of: (a) reaction of the 1987 and 1989 gases with wall rock at 640 and 375 °C; (b) cooling of the 1987 gas from 870 to 100 °C with and without mineral fractionation; (c) cooling of the 1989 gas from 757 to 100 °C with and without mineral fractionation; and (d) mixing of the 1987 and 1989 gases with air. The 640 °C gas-rock reaction produces an assemblage consisting of silicates (tridymite, albite, diopside, sanidine and andalusite), oxides (magnetite and hercynite) and sulfides (bornite, chalcocite, molybdenite and sphalerite). The 375 °C gas-rock reaction produces dominantly silicates (quartz, albite, andalusite, microcline, cordierite, anorthite and tremolite) and subordinate amounts of sulfides (pyrite, chalcocite and wurtzite), oxides (magnetite), sulfates (anhydrite) and halides (halite). The cooling calculations produce: (a) anhydrite, halite, sylvite; (b) Cu, Mo, Fe and Zn sulfides; (c) Mg fluoride at high temperature (> 370 °C); (d) chlorides, fluorides and sulfates of Mn, Fe, Zn, Cu and Al at intermediate temperature (170-370 °C); and (e) hydrated sulfates, liquid sulfur, crystalline sulfur, hydrated sulfuric acid and water at low temperature

Getahun, Aberra; Reed, Mark H.; Symonds, Robert

1996-05-01

3

Wall-rock argillic alteration and uranium mineralization of the northwestern Strel’tsovka caldera  

Microsoft Academic Search

Alteration of rocks and localization of uranium mineralization in the northwestern Strel’tsovka caldera are exemplified in\\u000a the Dal’nee deposit. In the main parameters of hydrothermal mineralization (temperature, pH, pressure, and composition of\\u000a solution), the Dal’nee deposit differs from the deposits of the Strel’tsovka ore field located in the central part of the\\u000a caldera. The localization of high-grade stratiform orebodies are

O. V. Andreeva; V. A. Golovin; V. A. Petrov

2010-01-01

4

The mineral chemistry of hydrothermally altered and metamorphosed wall-rocks at the Stollberg Fe-Pb-Zn-Mn(Ag) deposit, Bergslagen, Sweden  

Microsoft Academic Search

The c. 1.9 Ga old Stollberg sulphide and Mnrich skarn iron ores and sulphide ores in Bergslagen, south-central Sweden are hosted by hydrothermally altered and metamorphosed felsic volcanic and volcaniclastic rocks. The ores are underlain by comformable alteration zones characterized by albite-gedrite-quartz and biotite-muscovite-plagioclase-K-feldspar-quartz +\\/- garnet assemblages. The present mineralogies are interpreted as medium-grade metamorphic equivalents to the original alteration

M. Ripa

1994-01-01

5

The mineral chemistry of hydrothermally altered and metamorphosed wall-rocks at the Stollberg Fe-Pb-Zn-Mn(-Ag) deposit, Bergslagen, Sweden  

NASA Astrophysics Data System (ADS)

The c. 1.9 Ga old Stollberg sulphide and Mnrich skarn iron ores and sulphide ores in Bergslagen, south-central Sweden are hosted by hydrothermally altered and metamorphosed felsic volcanic and volcaniclastic rocks. The ores are underlain by comformable alteration zones characterized by albite-gedrite-quartz and biotite-muscovite-plagioclase-K-feldspar-quartz +/- garnet assemblages. The present mineralogies are interpreted as medium-grade metamorphic equivalents to the original alteration mineral assemblages. PT-conditions during prograde regional metamorphism are semiquantatively determined to be 510 to 560 °C at approximately 3 kbar. With increasing modal content of gedrite and biotite in the alteration zones, the Mg/Fe ratios and XMg's in octahedral positions of these minerals also increase. In the gedrite-bearing strata, whole-rock Mg/Fe ratios remain constant, whereas in the biotite-rich unit the wholerock Mg/Fe trend is parallel to that of the biotites. The trends in the metamorphic mineral composition are interpreted to be a product of original changes in fluid composition during the evolution of a sub-seafloor hydrothermal system. During the initial stage of alteration, Fe-Mn-rich fluids altered the rocks, and during a later stage, the fluids became more Mg-rich, possibly due to entrainment of fresh seawater, and the alteration zones became relatively more Mg-rich. Sulphide precipitation was contemperaneous with Mg metasomatism, suggesting base metal precipitation was a function of the mixing of cool seawater with hydrothermal fluid. It is proposed that early hydrothermal alteration was associated with the deposition of areally extensive Fe-oxide formation, and that Mg metasomatism defines a second stage of hydrothermal activity during which sulphide mineralization overprinted the earlier formed Fe-oxide deposit.

Ripa, M.

1994-06-01

6

Comparison of metasomatic reactions between a common CO2-rich vein fluid and diverse wall rocks: intensive variables, mass transfers, and Au mineralization at Alleghany, California  

USGS Publications Warehouse

The gold deposits at Alleghany, California, are typical of many epigenetic gold-bearing hydrothermal vein systems in metamorphic terranes worldwide. Detailed analyses of alteration halos in serpentinite, mafic amphibolite, and granite wall rocks at Alleghany indicate that widely contrasting deposit types, ranging from fuchsite-carbonate schists to pyrite-albitites, resulted when different wall rocks interacted with the same externally derived CO2-rich hydrothermal vein fluid. Patterns of element redistribution within halos and among lithologic units suggest a complex process involving fluid flow along vein fractures and diffusion (?? infiltration) normal to the veins. Wall rocks locally controlled both the directions and magnitudes of chemical fluxes across vein walls. -from Author

Bohlke, J. K.

1989-01-01

7

Aqueous alteration of VHTR fuels particles under simulated geological conditions  

NASA Astrophysics Data System (ADS)

Very High Temperature Reactor (VHTR) fuels consist of the bistructural-isotropic (BISO) or tristructural-isotropic (TRISO)-coated particles embedded in a graphite matrix. Management of the spent fuel generated during VHTR operation would most likely be through deep geological disposal. In this framework we investigated the alteration of BISO (with pyrolytic carbon) and TRISO (with SiC) particles under geological conditions simulated by temperatures of 50 and 90 °C and in the presence of synthetic groundwater. Solid state (scanning electron microscopy (SEM), micro-Raman spectroscopy, electron probe microanalyses (EPMA) and X-ray photoelectron spectroscopy (XPS)) and solution analyses (ICP-MS, ionique chromatography (IC)) showed oxidation of both pyrolytic carbon and SiC at 90 °C. Under air this led to the formation of SiO2 and a clay-like Mg-silicate, while under reducing conditions (H2/N2 atmosphere) SiC and pyrolytic carbon were highly stable after a few months of alteration. At 50 °C, in the presence and absence of air, the alteration of the coatings was minor. In conclusion, due to their high stability in reducing conditions, HTR fuel disposal in reducing deep geological environments may constitute a viable solution for their long-term management.

Ait Chaou, Abdelouahed; Abdelouas, Abdesselam; Karakurt, Gökhan; Grambow, Bernd

2014-05-01

8

A mechanism for high wall-rock velocities in rockbursts  

USGS Publications Warehouse

Considerable evidence has been reported for wall-rock velocities during rockbursts in deep gold mines that are substantially greater than ground velocities associated with the primary seismic events. Whereas varied evidence suggests that slip across a fault at the source of an event generates nearby particle velocities of, at most, several m/s, numerous observations, in nearby damaged tunnels, for instance, imply wall-rock velocities of the order of 10 m/s and greater. The common observation of slab buckling or breakouts in the sidewalls of damaged excavations suggests that slab flexure may be the mechanism for causing high rock ejection velocities. Following its formation, a sidewall slab buckles, causing the flexure to increase until the stress generated by flexure reaches the limit 5 that can be supported by the sidewall rock. I assume here that S is the uniaxial compressive strength. Once the flexural stress exceeds S, presumably due to the additional load imposed by a nearby seismic event, the slab fractures and unflexes violently. The peak wall-rock velocity v thereby generated is given by v=(3 + 1-??2/2)1 2 S/?????E for rock of density ??, Young's modulus E, and Poisson's ratio ??. Typical values of these rock properties for the deep gold mines of South Africa yield v= 26 m/s and for especially strong quartzites encountered in these same mines, v> 50m/s. Even though this slab buckling process leads to remarkably high ejection velocities and violent damage in excavations, the energy released during this failure is only a tiny fraction of that released in the primary seismic event, typically of magnitude 2 or greater.

McGarr, A.

1997-01-01

9

Scale of pluton\\/wall rock interaction near May Lake, Yosemite National Park, CA, USA  

Microsoft Academic Search

Interaction of magma with wall rock is an important process in igneous petrology, but the mechanisms by which interactions\\u000a occur are poorly known. The western outer granodiorite of the Cretaceous Tuolumne Intrusive Suite of Yosemite National Park,\\u000a California, intruded a variety of metasedimentary and igneous wall rocks at 93.1 Ma. The May Lake metamorphic screen is a\\u000a metasedimentary remnant whose contact

Ryan D. Mills; Allen F. Glazner; Drew S. Coleman

2009-01-01

10

Kimberlite Wall Rock Fragmentation: Venetia K08 Pipe Development  

NASA Astrophysics Data System (ADS)

Volcanic systems impose powerful disrupting forces on the country rock into which they intrude. The nature of the induced brittle deformation or fragmentation can be characteristic of the volcanic processes ongoing within the volcanic system, but are most typically partially removed or obscured by repeated, overprinting volcanic activity in mature pipes. Incompletely evolved pipes may therefore provide important evidence for the types and stages of wall rock fragmentation, and mechanical processes responsible for the fragmentation. Evidence for preserved stages of fragmentation is presented from a detailed study of the K08 pipe within the Cambrian Venetia kimberlite cluster, South Africa. This paper investigates the growth history of the K08 pipe and the mechanics of pipe development based on observations in the pit, drill core and thin sections, from geochemical analyses, particle size distribution analyses, and 3D modeling. Present open pit exposures of the K08 pipe comprise greater than 90% mega-breccia of country rock clasts (gneiss and schist) with <10% intruding, coherent kimberlite. Drill core shows that below about 225 m the CRB includes increasing quantities of kimberlite. The breccia clasts are angular, clast-supported with void or carbonate cement between the clasts. Average clast sizes define sub-horizontal layers tens of metres thick across the pipe. Structural and textural observations indicate the presence of zones of re-fragmentation or zones of brittle shearing. Breccia textural studies and fractal statistics on particle size distributions (PSD) is used to quantify sheared and non- sheared breccia zones. The calculated energy required to form the non-sheared breccia PSD implies an explosive early stage of fragmentation that pre-conditions the rock mass. The pre-conditioning would have been caused by explosions that are either phreatic or phreatomagmatic in nature. The explosions are likely to have been centered on a dyke, or pulses of preceding volatile-fluid phases, which have encountered a local hydrologically active fault. The explosions were inadequate in mechanical energy release (72% of a mine production blast) to eject material from the pipe, and the pipe may not have breached surface. The next stage of fragmentation is interpreted to have been an upward-moving collapse of the pre-conditioned hanging wall of a subterranean volcanic excavation. This would explain the mega-scale layering across the width of the breccia pipe. It must be questioned whether the preserved K08 architecture represents early pipe development in general, or is a special case of a late pipe geometry modification process. Previous literature describes sidewall and hanging wall caving processes elsewhere in the Venetia cluster and other kimberlites world wide. A requirement for emplacement models that include upward pipe growth processes is the availability of space (mass deficit at depth) into which the caving and/or dilating breccia can expand. It is possible that K08 might be connected to adjacent K02 at a depth somewhere below 400m, which would explain the presence of volcaniclastic kimberlite at depth within the K08 pipe. K08 is likely an incomplete ancillary sideward development to K02. The latest stage of brecciation is quantified through an observed evolution in the fractal dimension of the PSD. It is interpreted to be due to complex adjustments in volume in the pipe causing shearing and re-fragmentation of the breccia.

Barnett, W.; Kurszlaukis, S.; Tait, M.; Dirks, P.

2009-05-01

11

Sulfide solubilities in Alteration-controlled Systems  

USGS Publications Warehouse

Solubilities of sphalerite (ZnS) and galena (PbS) were determined at 300?? to 500??C and 1000 bars total pressure in a chemical environment buffered by silicate mineral equilibria. Chloride solutions and muscovite-bearing assemblages characteristic of hydrothermal wall-rock alteration were used; weak acidities at temperature were therefore involved. The metal concentrations encountered tended to be higher than those observed in high bisulfide-H2S systems at neutral to weakly basic pH used in most previous experimentation; the chemical conditions of the work, although not completely satisfactory, are geologically more realistic than previous experimentation done in the basic-pH region.

Hemley, J. J.; Meyer, C.; Hodgson, C. J.; Thatcher, A. B.

1967-01-01

12

Global geologic context for rock types and surface alteration on Mars  

USGS Publications Warehouse

Petrologic interpretations of thermal emission spectra from Mars orbiting spacecraft indicate the widespread occurrence of surfaces having basaltic and either andesitic or partly altered basalt compositions. Global concentration of ice-rich mantle deposits and near-surface ice at middle to high latitudes and their spatial correlation with andesitic or partly altered basalt materials favor the alteration hypothesis. We propose the formation of these units through limited chemical weathering from basalt interactions with icy mantles deposited during periods of high obliquity. Alteration of sediments in the northern lowlands depocenter may have been enhanced by temporary standing bodies of water and ice. ?? 2004 Geological Society of America.

Wyatt, M. B.; McSween, Jr. , H. Y.; Tanaka, K. L.; Head, III, J. W.

2004-01-01

13

On Two-Phase Relative Permeability and Capillary Pressure of Rough-Walled Rock Fractures  

Microsoft Academic Search

This paper presents a conceptual and numerical model of multiphase flow in fractures. The void space of real rough-walled rock fractures is conceptualized as a two-dimensional heterogeneous porous medium, characterized by aperture as a function of position in the fracture plane. Portions of a fracture are occupied by wetting and nonwetting phase, respectively, according to local capillary pressure and global

K. Pruess; Y. W. Tsang

1990-01-01

14

Two-phase flow visualization and relative permeability measurement in natural rough-walled rock fractures  

Microsoft Academic Search

A laboratory flow apparatus was used to visualize and measure two-phase gas-liquid flows in natural rough-walled rock fractures. Experiments at carefully controlled flow rate and pressure conditions have been performed using a natural fracture and three transparent fracture replicas. Two-phase flow exhibited persistent instabilities with cyclic pressure and flow rate variations even under conditions of constant applied boundary conditions. Visual

P. Persoff; K. Pruess

1995-01-01

15

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

16

Geology and porphyry copper-type alteration-mineralization of igneous rocks at the Christmas Mine, Gila County, Arizona  

USGS Publications Warehouse

The Christmas copper deposit, located in southern Gila County, Arizona, is part of the major porphyry copper province of southwestern North America. Although Christmas is known for skarn deposits in Paleozoic carbonate rocks, ore-grade porphyry-type copper mineralization also occurs in a composite granodioritic intrusive complex and adjacent mafic volcanic country rocks. This study considers the nature, distribution, and genesis of alteration-mineralization in the igneous rock environment at Christmas. At the southeast end of the Dripping Spring Mountains, the Pennsylvanian Naco Limestone is unconformably overlain by the Cretaceous Williamson Canyon Volcanics, a westward-thinning sequence of basaltic volcanic breccia and lava flows, and subordinate clastic sedimentary rocks. Paleozoic and Mesozoic strata are intruded by Laramide-age dikes, sills, and small stocks of hornblende andesite porphyry and hornblende rhyodacite porphyry, and the mineralized Christmas intrusive complex. Rocks of the elongate Christmas stock, intruded along an east-northeast-trending fracture zone, are grouped into early, veined quartz diorite (Dark Phase), biotite granodiorite porphyry (Light Phase), and granodiorite; and late, unveined dacite porphyry and granodiorite porphyry. Biotite rhyodacite porphyry dikes extending east and west from the vicinity of the stock are probably coeval with biotite granodiorite porphyry. Accumulated normal displacement of approximately 1 km along the northwest-trending Christmas-Joker fault system has juxtaposed contrasting levels (lower, intrusive-carbonate rock environment and upper, intrusive-volcanic rock environment) within the porphyry copper system. K-Ar age determinations and whole-rock chemical analyses of the major intrusive rock types indicate that Laramide calc-alkaline magmatism and ore deposition at Christmas evolved over an extended period from within the Late Cretaceous (~75-80 m.y. ago) to early Paleocene (~63-61 m.y. ago). The sequence of igneous rocks is progressively more alkaline and silicic from basalt to granodiorite. Early (Stage I) chalcopyrite-bornite (-molybdenite) mineralization and genetically related K-silicate alteration are centered on the Christmas stock. K-silicate alteration is manifested by pervasive hornblende-destructive biotitization in the stock, biotitization of basaltic volcanic wall rocks, and a continuous stockwork of K-feldspar veinlets and quartz-K-feldspar veins in the stock and quartz-sulfide veins in volcanic rocks. Younger (Stage II) pyrite-chalcopyrite mineralization and quartz-sericite-chlorite alteration occur in a zone overlapping with but largely peripheral to the zone of Stage I stockwork veins. Within the Christmas intrusive complex, K-silicate-altered rocks in the central stock are flanked east and west by zones of fracture-controlled quartz-sericite alteration and strong pyritization. In volcanic rocks quartz-chlorite-pyrite-chalcopyrite veins are superimposed on earlier biotitization and crosscut Stage I quartz-sulfide veins. Beyond the zones of quartz-sericite alteration, biotite rhyodacite porphyry dikes contain the propylitic alteration assemblage epidote-chlorite-albite-sphene. Chemical analyses indicate the following changes during pervasive alteration of igneous rocks: (1) addition of Si, K, H, S, and Cu, and loss of Fe 3+ and Ca during intense biotitization of basalt; (2) loss of Na and Ca, increase of Fe3+/Fe2+, and strong H-metasomatism during sericitization of quartz diorite; and (3) increase in Ca, Na, and Fe3+/Fe2+, and loss of K during intense propylitization of biotite rhyodacite porphyry dikes. Thorough biotitization of biotite granodiorite porphyry in the Christmas stock was largely an isochemical process. Fluid-inclusion petrography reveals that Stage I veins are characterized by low to moderate populations of moderate-salinity and gas-rich inclusions, and sparse but ubiquitous halite-bearing inclusions. Moderate-salinity an

Koski, Randolph A.

1979-01-01

17

Geology  

NSDL National Science Digital Library

With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on the many different kinds of geological exploration. The elements that make up minerals and the different ways minerals are developed, The special characteristics of minerals, like physical properties, is explained. Earths tectonic plates, the reasons they move, and the effects of the shifting are also given. Also featured is fossils and how they are developed and are found, as well as why fossils are useful tools for scientists.

Bergman, Jennifer

2009-08-03

18

Magma dynamics and wall-rock composition control the environmental impact of magmatic events  

NASA Astrophysics Data System (ADS)

A key control on the destructive consequences of the emplacement of large igneous provinces such as Siberia and Deccan is the type of sedimentary rock in basins beneath the flood basalts. Contact metamorphism around intrusions in carbonates (dolostones or limestones), sulphates (evaporites), coal or organic-rich shale generates large quantities of greenhouse and toxic gases (CO2, CH4, SO2) which subsequently vent to the atmosphere and cause global warming and mass extinctions. Recently we demonstrated that the release of sediment-derived gases had a far greater impact on the environment than the emission of magmatic gases. Here we compare the effects of contact metamorphism of different types of carbonated sediments. We estimate that about 220 kg of CO2 were released per ton of metamorphosed dolomite in Sichuan basin around the plumbing system of Emeishan large igneous province in China. New structural studies show that during emplacement of the main intrusion, multiple generations of mafic dykes invaded the marbles of the lower metamorphic aureole. These dykes reacted extensively with the marble, and the magma actively assimilated wall-rock dolostone, a process that potentially released the entire CO2 budget of the assimilated carbonate, or 477 kg/ton. We compare this result with a second case, the Aguablanca intrusion in Spain, where mafic magma intruded limestones and shales. Contact metamorphism of pure limestone produced very little CO2 (less than 50 kg of CO2 per ton of pure limestone) whereas, in impure dolostones, the presence of silica or clay allowed the formation of calc-silicate minerals and strongly increased the CO2 yield, to140 kg CO2 per ton. In contrast, studies by Svensen and coworkers of sills in the Karoo province reveal lower rates of emission, mainly from decomposition of hydrocarbons around passively emplaced intrusions. Therefore, to understand the full impact on environment of the release of thermogenic gases during a major magmatic event, we need to take into account both the types of wall rock and dynamics of magma emplacement.

Arndt, N.; Ganino, C.; Pêcher, A.; Chauvel, C.; Zhou, M.; Tornos, F.

2010-12-01

19

Non-Darcian two-phase flow in a transparent replica of a rough-walled rock fracture  

Microsoft Academic Search

This article presents experimental results for single- and two-phase flows at high flow rates through a replica of an actual rough-walled rock fracture. The results of the single-phase flow are interpreted using non-Darcian laws: the weak inertia cubic law, Forchheimer's law, and the full cubic law. They allow the determination of the fracture's intrinsic properties (absolute permeability and inertial coefficient).

Ali Nowamooz; Giovanni Radilla; Mostafa Fourar

2009-01-01

20

Structural and Geologic Relationships Between Igneous Rocks and Their Alteration Products in Xanthe Terra, Mars  

NASA Astrophysics Data System (ADS)

Examination of CRISM data over Xanthe Terra reveals phyllosilicate, hydrated sulfate, and olivine- and pyroxene-rich occurrences. Investigating the stratigraphic and geologic contexts of these deposits can shed light on their formation and timing.

Lichtenberg, K. A.; Arvidson, R. E.; Murchie, S. L.; Roach, L. H.; Andrews-Hanna, J. C.; Noe Dobrea, E. Z.; Mustard, J. F.

2008-03-01

21

Wall rock-magma interactions in Etna, Italy, studied by U-Th disequilibrium and rare earth element systematics  

SciTech Connect

[sup 230]Th/[sup 238]U disequilibria have been studied in xenoliths and associated lavas of the 1892 and 1989 eruptions of Etna. Most xenoliths are out of secular equilibrium within 1 [sigma] errors and have lower [sup 230]Th/[sup 232]Th ratios than their host magmas. Siliceous and peraluminous xenoliths display large ranges of Th/U ratios for similar [sup 230]Th/[sup 232]Th values, which are interpreted in terms of Th isotopic rehomogenization. The siliceous xenoliths have also suffered thorium and uranium enrichments, which are best explained by chemical diffusion between xenolith melts and differentiated magmas. Estimates of thorium self-diffusivities and [sup 230]Th-[sup 238]U disequilibria give age constraints on these events corresponding to the last major volcanic event of Etna at 14 ka (formation of the elliptic crater caldera). These results suggest that magma storage in superficial and long-lived magma chambers favors the thorium isotopic homogenization of wall rocks by a thermal effect. Chemical diffusion of uranium and thorium and isotopic homogenization between siliceous melts of wall rocks and differentiated magmas may significantly modify the initial thorium isotopic compositions. Such contamination processes could explain the large variations of the [sup 230]Th/[sup 232]Th initial ratios of Etna magmas. 33 refs., 7 figs., 1 tab.

Villemant, B. (Universite Paris 6 (France) CNRS URA 196, Paris (France)); Michaud, V.; Metrich, N. (LPS/CEA-CNRS, Gif-sur-Yvette (France))

1993-03-01

22

Pore-space alteration induced by brine acidification in subsurface geologic formations  

NASA Astrophysics Data System (ADS)

A new Lagrangian particle-based method is presented to simulate reactive transport in natural porous media. This technique is based on Modified Moving Particle Semi-implicit (MMPS) and takes as input high-resolution voxel images of natural porous media. The flow field in the medium is computed by solving the incompressible Navier-Stokes equations. Moreover, a multicomponent ion transport model is coupled with a homogeneous and heterogeneous reactions module to handle pore-space alteration (i.e., pore-wall dissolution). The model is first successfully validated against the experimental data available in the literature. Subsequently, X-ray microtomographic images of two naturally occurring porous media are used to investigate the impact of reaction kinetics and pore-space topology on pore-space alteration induced by brine acidification in subsurface conditions. We observed that at the normal rates of reactions no significant change in porosity and permeability takes place in the short term. Whereas, higher reaction rates caused major changes in the macroscopic properties (e.g., porosity and permeability) of the rocks. We also show that these changes are strongly affected by the rocks' pore-scale topologies.

Ovaysi, Saeed; Piri, Mohammad

2014-01-01

23

Geology, mineralization, and hydrothermal alteration and relationships to acidic and metal-bearing surface waters in the Palmetto Gulch area, southwestern Colorado  

USGS Publications Warehouse

The Palmetto Gulch area is affected by low pH and metal-bearing drainage from abandoned mines, and perhaps, from natural weathering around vein zones. To investigate these anthropogenic and potential natural sources of acidity and metals, we mapped the geology, veins, and hydrothermally altered areas; conducted mine dump leachate studies; and collected reconnaissance water quality data. Several small abandoned mines are present in the Palmetto Gulch area that produced small amounts of relatively high-grade silver ore from fault-controlled polymetallic vein deposits. These veins are hosted in lavas, breccias, and related volcaniclastic sediments that ponded within the 28 Ma San Juan-Uncompahgre caldera complex. These rock units generally have conformable contacts and have shallow dips to the northwest. Lava flows of pyroxene andesite, which host the Roy-Pray mine, are massive near their base and typically grade upward into tightly jointed rock with 2-15 cm joint spacing. In general, most hydrothermally altered rock within the Palmetto Gulch area is restricted to envelopes surrounding the mineralized veins and faults. Composite zones of vein-related alteration vary from about 50 to 80 m wide along the high ridgelines and narrow to less than 10 to 15 m beneath an elevation of about 5,462 m. Where unaffected by surficial oxidation, these altered zones contain as much as 7 to 10 volume percent finely-disseminated pyrite. The majority of rocks in the area were affected by regional and vein-related propylitic alteration. These greenish-colored rocks have alteration products consisting of chlorite, illite, and calcite; and feldspars are typically weakly altered. Most of these rocks have detectable amounts of calcite, while as much as 11 percent by weight was detected in samples collected during this study. The Palmetto Gulch area is affected by low pH and metal-bearing drainage from abandoned mines, and perhaps, from natural weathering around vein zones. To investigate these anthropogenic and potential natural sources of acidity and metals, we mapped the geology, veins, and hydrothermally altered areas; conducted mine dump leachate studies; and collected reconnaissance water quality data. Several small abandoned mines are present in the Palmetto Gulch area that produced small amounts of relatively high-grade silver ore from fault-controlled polymetallic vein deposits. These veins are hosted in lavas, breccias, and related volcaniclastic sediments that ponded within the 28 Ma San Juan-Uncompahgre caldera complex. These rock units generally have conformable contacts and have shallow dips to the northwest. Lava flows of pyroxene andesite, which host the Roy-Pray mine, are massive near their base and typically grade upward into tightly jointed rock with 2-15 cm joint spacing. In general, most hydrothermally altered rock within the Palmetto Gulch area is restricted to envelopes surrounding the mineralized veins and faults. Composite zones of vein-related alteration vary from about 50 to 80 m wide along the high ridgelines and narrow to less than 10 to 15 m beneath an elevation of about 5,462 m. Where unaffected by surficial oxidation, these altered zones contain as much as 7 to 10 volume percent finely-disseminated pyrite. The majority of rocks in the area were affected by regional and vein-related propylitic alteration. These greenish-colored rocks have alteration products consisting of chlorite, illite, and calcite; and feldspars are typically weakly altered. Most of these rocks have detectable amounts of calcite, while as much as 11 percent by weight was detected in samples collected during this study.

Bove, Dana J.; Kurtz, Jeffrey P.; Wright, Winfield G.

2002-01-01

24

Interior layered deposits within a perched basin, southern Coprates Chasma, Mars: Evidence for their formation, alteration, and erosion  

NASA Astrophysics Data System (ADS)

A basin-like area containing three interior layer deposits (ILDs) on the southern margin of Coprates Chasma was studied. We interpret the area as an ancestral basin and demonstrate that ILD deposition postdates the formation of the current wall rock slopes. The geometry of the ILD and the wall rock spurs form a catchment area between each ILD and the plateau to the south. Erosional remnants of extensive ash or dust layers deposited on the plateau south of Valles Marineris also crop out on the southern plateau of Coprates Chasma. A mass balance calculation suggests that the volume of each ILD is compatible with the volume of the ash or dust that would have been deposited within each catchment area. We propose that the ILDs likely formed by episodically washing such aerially deposited material down from chasma walls. Rifting of the Ius-Melas-Coprates graben opened the enclosed basin and removed any standing water. Faults within the ILDs are compatible with this chasm opening. Sulfates are associated with the ILDs and light-toned material on the basin floor. We suggest that they result from water alteration of preexisting deposits, though the timing of that alteration may predate or postdate the breaching of the basin. Scours within one ILD are similar to terrestrial glacial scours. During a period of high obliquity ice would accumulate in this region; hence we argue the scours are Martian glacial scours. A late deposited layer marks the end of the active local geological history between 100 My and 1 Gy.

Fueten, F.; Flahaut, J.; Le Deit, L.; Stesky, R.; Hauber, E.; Gwinner, K.

2011-02-01

25

Predicting long-term geochemical alteration of wellbore cement in a generic geological CO 2 confinement site: Tackling a difficult reactive transport modeling challenge  

NASA Astrophysics Data System (ADS)

SummaryThe safety of the future CO 2 geological storage is largely dependent on the integrity of existing surrounding wells. Well integrity is of major concern in confinement sites where the number of abandoned wells is particularly high, such as it often occurs in depleted gas and/or oil fields. The degradation of the cement filling of these wells is a key issue to insure the confinement of the CO 2. Laboratory experiments are unable to produce data for long periods of interaction; therefore, numerical modeling stands as a powerful means to predict the long-term evolution of the cement plugs, and to assess well integrity and leakage risk for the confining system. We thus present the results of a set of numerical simulations that predict the evolution of fluid chemistry and mineral alteration in the cement of an idealized abandoned wellbore at the top of the Dogger aquifer in Paris Basin, France, where CO 2 geological disposal is currently under consideration. A continuum-based reactive transport formulation has been adopted which accounts for multi-component reactivity under water saturated and diffusion-controlled mass transfer conditions. Simplified two-dimensional models have been applied to simulate the complex geochemical interactions occurring at the interfaces between cement, aquifer and caprock domains. The simulations predict a two-stage evolution of the cement porous matrix, after interaction with acid fluids from reservoir: (i) a first, "clogging" stage, characterized by a decrease in porosity due to calcite precipitation, and (ii) a second stage of porosity reopening, related to the disappearance of primary cement phases, and the re-dissolution of secondary minerals, such as zeolites. Overall, the interaction with acid fluids causes a severe mineralogical alteration of the cement and the development of a carbonated, low-porosity layer near the reservoir interface. As the caprock imposes a high partial pressure of CO 2, some mineralogical alteration of the cement is promoted also at the interface with the caprock. This pattern of reaction results in a large increase in porosity that might lead to the formation of vertical ascent route for reservoir fluids.

Gherardi, Fabrizio; Audigane, Pascal; Gaucher, Eric C.

2012-02-01

26

Geologic Maps  

NSDL National Science Digital Library

This web site provides an introduction to geologic maps. Topics covered include what is a geologic map, unique features of geologic maps, letter symbols, faults, and strike and dip. Users may click to view colored geologic maps, the geologic map of the United States and the geologic relief map of the United States.

Graymer, Russell

27

Geologic Explorations  

NSDL National Science Digital Library

Geologic Explorations allows learners to explore a variety of unique geological formations of Utah using Quicktime Virtual Reality (QTVR) panoramas and digital still imagery. Spectacular panoramas and striking images capture Utah's unique geology and invite students to explore and learn interesting facts and concepts central to the study of geology.

Bodzin, Alec

2002-04-01

28

Geologic Maps  

NSDL National Science Digital Library

Geologic Maps are unique in that they show the distribution of geologic features on a landscape through specific symbols and colors. The United States Geological Survey's (USGS) site Geologic Maps provides visitors with a good introduction to these concepts, which include the unique features of a geologic map; the meaning of their lines, colors, and symbols; the location of faults; and more. Anyone working with geologic maps or just interested in learning a little about cartography or geology will find this site easy to explore and full of good information.

2000-01-01

29

Geological images  

NSDL National Science Digital Library

This site from Marli Bryant Miller, a professor at the University of Oregon, presents images of geological features from around the world. Photographs of glacial features, igneous and metamorphic rocks and processes, and structural geology are featured.

Miller, Marli B.; Oregon, University O.

30

Structural Geology  

NSDL National Science Digital Library

Created by the University of Nebraska-Lincoln, this site describes the basics of structural geology with text and images. The page includes the discussion of stress, strain, strike and dip, faults, folds, mountain building, erosion, economic geology, and environmental geology. This is a nice introduction to the basic topics in geology. Images from the field help to enhance the topics on the site. Instructors can use this resource to help create or simply enhance their curriculum.

2009-05-21

31

Geological Time  

NSDL National Science Digital Library

"Why do engineers need to know about geologic time?" That question is answered in this resource from the University of Saskatchewan's Department of Civil and Geological Engineering. Provided here is a discussion of the concepts of geological time; relative dating methods, such as correlation; and absolute dating methods, such as radiometric methods. Diagrams and charts are included to demonstrate these complex concepts.

2008-04-17

32

Geology of five small Australian impact craters  

USGS Publications Warehouse

Here we present detailed geological maps and cross-sections of Liverpool, Wolfe Creek, Boxhole, Veevers and Dalgaranga craters. Liverpool crater and Wolfe Creek Meteorite Crater are classic bowlshaped, Barringer-type craters, Liverpool was likely formed during the Neoproterozoic and was filled and covered with sediments soon thereafter. In the Cenozoic, this cover was exhumed exposing the crater's brecciated wall rocks. Wolfe Creek Meteorite Crater displays many striking features, including well-bedded ejecta units, crater-floor faults and sinkholes, a ringed aeromagnetic anomaly, rim-skirting dunes, and numerous iron-rich shale balls. Boxhole Meteorite Crater, Veevers Meteorite Crater and Dalgaranga crater are smaller, Odessa-type craters without fully developed, steep, overturned rims. Boxhole and Dalgaranga craters are developed in highly follated Precambrian basement rocks with a veneer of Holocene colluvium. The pre-existing structure at these two sites complicates structural analyses of the craters, and may have influenced target deformation during impact. Veevers Meteorite Crater is formed in Cenozoic laterites, and is one of the best-preserved impact craters on Earth. The craters discussed herein were formed in different target materials, ranging from crystalline rocks to loosely consolidated sediments, containing evidence that the impactors struck at an array of angles and velocities. This facilitates a comparative study of the influence of these factors on the structural and topographic form of small impact craters. ?? Geological Society of Australia.

Shoemaker, E. M.; Macdonald, F. A.; Shoemaker, C. S.

2005-01-01

33

Ad Duwayhi, Saudi Arabia: Geology and geochronology of a neoproterozoic intrusion-related gold system in the Arabian shield  

USGS Publications Warehouse

The Ad Duwayhi gold deposit, located in the east-central part of the Arabian shield, is the newest gold discovery in Saudi Arabia. Exploration to date has identified a gold resource of greater than 1 million ounces (oz) with significant potential for expansion. Gold mineralization was closely associated, in time and space, with emplacement of a late- to postorogenic, intracrustal, northwest-oriented granite body (659 ?? 7 Ma) and comagmatic square quartz porphyry (646 ?? 11 Ma), a hypabyssal and perhaps younger phase of the granite. Mineralization was largely confined to northeast-striking, southeast-dipping fault zones. Hydrothermal alteration consisted of early biotitic alteration overprinted by sericitic alteration. Sericitic alteration was coincident with gold mineralization and produced a quartz-sericite-carbonate-pyrite-rutile mineral assemblage, found both as vein fill and wall-rock alteration products. Mineralization styles, in the following general paragenetic sequence, include (1) quartz-molybdenite veins in and near the granite stock, (2) low-grade gold-bearing quartz vein breccia in and along the margins of the granite stock, (3) gold-bearing stockwork and sheeted quartz veins, and (4) massive to banded gold-rich tabular quartz veins. The gold-bearing stockwork, sheeted, and tabular veins are generally spatially associated with square quartz porphyry dikes and more distal to the granite stock. Mineralized zones at Ad Duwayhi are characterized by low sulfide and base metal content and gold/silver ratios of approximately 6/1. Gold shows no significant correlation with other metals, except lead, and moderate correlation with silver. Re-Os dating of molybdenite from a quartz-molybdenite vein and a tabular quartz vein with cogenetic gold produced robust ages of 655.6 ?? 2.7 and 649.9 ?? 2.3 Ma, respectively, documenting that gold mineralization and crystallization of granite and square quartz porphyry were, within uncertainty, coeval events. This age correlation combined with granite textural features, the presence of unidirectional solidification textures in granite and square quartz porphyry, and the nature and time-space distribution of mineralization styles, all indicate that mineralization evolved in and near the interface between a crystallizing magma and the surrounding rocks and, thus, is consistent with an intrusion-related genesis. In light of our findings at Ad Duwayhi, a reassessment of similar intrusion-hosted deposits in the Arabian shield is warranted, and areas of late- to postorogenic plutonism, particularly in the Afif composite terrane, should be considered prospective for intrusion-related gold systems. ??2004 by Economic Geology.

Doebrich, J. L.; Zahony, S. G.; Leavitt, J. D.; Portacio, Jr. , J. S.; Siddiqui, A. A.; Wooden, J. L.; Fleck, R. J.; Stein, H. J.

2004-01-01

34

Alteration geochemistry and fluid inclusion characteristics of the greenstone-hosted gold deposit of Hutti, Eastern Dharwar Craton, India  

NASA Astrophysics Data System (ADS)

Gold mineralization of the Hutti mine, southern India, is situated in closely spaced laminated quartz veins and associated alteration haloes along steeply dipping shear zones within a sequence of rather uniform amphibolites. Intense shearing has resulted in large-scale mylonitization of the wall rocks. Anastomosing shear zones, with intervening lensoid bodies of unsheared amphibolites, are characteristic features of the deposit. The general pattern of symmetrical alteration comprises a distal zone of chlorite-rich rock, with a proximal biotite-rich zone adjacent to laminated quartz veins. Arsenopyrite thermometry yielded a temperature range of 350-477 °C for the biotite alteration zone, which preceded the formation of the laminated quartz veins. Mass balance calculations on the alteration zones indicate a gradual mass and volume loss during alteration. The alteration is accompanied by intense potash metasomatism and addition of sulfur, which resulted in the formation of arsenopyrite, pyrrhotite, and pyrite. Results of fluid inclusion studies suggest that low salinity (3.9-13.5 wt% NaCl equivalent) H2O-CO2 rich fluids were responsible for gold-rich laminated quartz vein formation in the Hutti deposit. These fluids constituted a later counterpart of the protracted fluid activity that first formed the biotite alteration zone. The estimated P-T values range from 1.0 to 1.7 kbar at 280-320 °C. These data, along with the alteration assemblages and the characteristic gold-sulfide association, both in the altered wall rock and laminated quartz veins, suggest that gold, transported as reduced bisulfide complexes, was deposited in response to sulfidation reactions in the wall rocks. Comparison of P-T conditions of formation of gold-quartz veins at Hutti with two other large gold deposits in the eastern Dharwar Craton, namely Kolar (1.8 kbar/280 °C) and western Ramagiri (1.45-1.7 kbar/240-270 °C), indicates broadly similar lode-gold forming conditions in the Dharwar Craton.

Pal, Nabarun; Mishra, Biswajit

2002-10-01

35

North Cascades Geology: Geologic Time  

NSDL National Science Digital Library

This article describes the period of geologic time spanned by the rocks of the North Cascades area of Washington. Users can access a simplified geologic time scale that provides links to geologic events in the North Cascades region. These include the deposition of various terranes, periods of intrusion and metamorphism, the beginning of the Cascade volcanic arc, and periods of major glaciation. Links to related materials are also provided.

36

Yosemite Geology  

NSDL National Science Digital Library

The National Park Service maintains the Yosemite National Park Web site and the corresponding Geology page. This Web site gives an overview of the geologic history of the site, tells how the Sierra Nevada range formed, explains the basics of granitic rock, shows how glaciers carved out the canyons, and much more.[JAB

37

Engineering Geology  

ERIC Educational Resources Information Center

Engineering geology remains a potpourri of applied classical geology, and 1977 witnessed an upswing in demand for these services. Traditional foundation-related work was slight, but construction related to national needs increased briskly. Major cities turned to concerns of transit waste-water treatment and solid-waste disposal. (Author/MA)

Hatheway, Allen W.

1978-01-01

38

Geologic Time.  

ERIC Educational Resources Information Center

One of a series of general interest publications on science topics, the booklet provides those interested in geologic time with an introduction to the subject. Separate sections discuss the relative time scale, major divisions in geologic time, index fossils used as guides for telling the age of rocks, the atomic scale, and the age of the earth.…

Newman, William L.

39

Physical geology  

SciTech Connect

The book integrates current thinking on processes (plate techtonics, chemical cycles, changes throughout geologic time). It is an introduction to investigations into the way the earth works, how mountains are formed, how the atmosphere, hydrosphere, crust and mantle interact with each other. Treatments on climate, paleoclimatology and landscape evolution are included, as is a discussion on how human activity affects geological interactions.

Skinner, B.; Porter, S.

1987-01-01

40

Geology and regional hydrothermal alteration of the crater-fill, Onaping Formation: Association with zinc lead copper mineralization, Sudbury Structure, Canada  

NASA Astrophysics Data System (ADS)

This study of the impact crater-fill sequence (Onaping Formation) in the Sudbury Structure reveals significant features critical to our understanding of modification processes and water-rock interaction in large (˜200 km) impact structures. The crater-fill sequence has a distinct mappable stratigraphy and consists of three informal members, the Garson, Sandcherry and Dowling, that have different vitric morphologies, percentage of matrix and lithic fragments and depositional characteristics. A distinct, coeval set of aphanitic dykes occupy syn-depositional faults and fractures. Similarities of trace, REE and isotopic data of least altered andesitic Onaping Formation melt, felsic norite and quartz diorite of the Sudbury Igneous Complex (SIC) supports the interpretation that they represent an initial melt composition. The Onaping Formation was emplaced early, prior to differentiation and/or emplacement of the SIC in its present position. Stratigraphy, morphology, structural controls and geochemistry of the Onaping Formation constrains the timing and evolution of the Sudbury Structure. A two stage history of crater-fill is recorded. Stage 1 involves, the emplacement of Garson and Sandcherry member units as products of slumping and fallback followed by intrusion of andesitic melt into crater floor-fractures. Stage 2 involves, large-scale, crater wall collapse along superfaults outside of the transient crater followed by melt-water interaction that resulted in "phreatomagmatic" explosive eruptions to produce the Dowling member. The basal intrusion was then injected along pre-existing fractures formed in Stage 1. The crater-fill succession records a major impact-induced, hydrothermal system at 1848.4 +3.8/-1.8 Ma that produced low temperature, (<250°C) carbonate-hosted Zn-Cu-Pb subseafloor replacement-type deposits within the crater-fill. Mineralogical, geochemical and mapping data show a complex hydrothermal history controlled by the structural, magmatic and stratigraphic history of the impact crater. Alteration zones include a regional, upper calcite zone, transition zone, chlorite zone, albite zone and lower silicification zone. Field, textural, stable and radiogenic isotope data for the regional carbonate zone are compatible with magmatic CO2 diluted by Proterozoic seawater. The Sudbury Structure is the largest, well preserved example of a terrestrial impact crater and records a distinct history of crater-fill emplacement and a productive hydrothermal system that is unparalleled in other impact craters on Earth.

Ames, Doreen Elizabeth

41

Geologic History  

NSDL National Science Digital Library

This unit introduces younger students to the concept of relative versus absolute time and how geologists determine the age of geologic events and features. Topics include the laws that determine relative age (superposition, cross-cutting relationships, included fragments, and others), and how to re-construct the geologic history of an area using these relationships. There is also information on geologic correlation and the use of index fossils to determine relative age. The section on absolute time discusses some ways of measurement (tree rings, radioactive dating) and introduces the concepts of natural selection and mass extinctions. A vocabulary and downloadable, printable student worksheets are provided.

Medina, Philip

2010-09-03

42

Geologic Time  

NSDL National Science Digital Library

The Earth is very old -- 4.5 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.

Newman, William L.

1997-01-01

43

Geologic Timeline  

NSDL National Science Digital Library

Dive into the depths of time with this Geologic Timeline. The farther you scroll down, the farther back in time you'll travel. Also, the longer a period is on this page, the longer it lasted in history!

2000-01-01

44

Structural Geology  

NASA Astrophysics Data System (ADS)

Structural geology and continental tectonics were ushered in to the modern quantitative age of geosciences with the arrival of the global plate tectonics paradigm (circa 1968), derived using new data from the oceans' depths, and John Ramsay's 1967 seminal work, Folding and Fracturing of Rocks. Fossen is to be applauded for crafting a unique, high-caliber, and accessible undergraduate textbook on structural geology that faithfully reflects this advance and the subsequent evolution of the discipline. This well-written text draws on Fossen's wealth of professional experience, including his broad and diverse academic research and experience in the petroleum industry. This book is beautifully illustrated, with excellent original color diagrams and with impressive color field photographs that are all keyed to locations and placed into geologic context.

Weber, John; Frankel, Kurt L.

2011-05-01

45

Teaching Geology  

NSDL National Science Digital Library

This rather remarkable website contains a great collection of resources for web-based instruction and demonstrations of geology concepts. The collection includes, under Classroom demonstration, the very useful SeisMac 3.0, which is an application for Mac OS X that turns a laptop computer into a " low-resolution strong-motion accelerometer," or a basic seismograph. It works by accessing the computer's Sudden Motion Sensor in order to display real-time, three axis accelerations graphs. Visitors can use the application to watch the seismic waves go up and down just by tapping their feet on the floor nearby. Other resources include Virtual Earth (an "interactive minicourse on thermal convection") and a link to Geology in the news, which collates important news stories with a geological theme.

46

Geologic Explorations  

NSDL National Science Digital Library

One of the latest offerings from the North Carolina State University's Web site Science Junction (last mentioned in the November 25, 1998 Scout Report) is the Geologic Explorations page. By clicking on the respective coordinates of each location, users can explore twelve areas in the western United States with 360-degree panoramic QuickTime movies and digital photography. Set up as a type of lesson for students, the main page suggests paying close attention to the unique geologic features and gives a few questions to answer about each area. The site is very easy to use and provides some breathtaking vistas of some of the most beautiful areas of the US.

Bodzin, Alec M.

2001-01-01

47

Geology Fieldnotes  

NSDL National Science Digital Library

This National Park Service (NPS) site delivers a brief description of the geology of the Black Hills National Park. Links to park maps, a photo album, books, videos, CDs, and a searchable data base of research needs that have been identified by the National Park Service are included. General information about the park's education and interpretive programs are also abailable.

National Park Services (NPS)

48

Antarctica Geology  

NSDL National Science Digital Library

This site contains information about the continent of Antarctica. There is a classroom practice and instructional module. The students will be able to describe the general geology of the land under the Antarctic ice and to explain from where the rocks may have come.

49

Geologic Time.  

ERIC Educational Resources Information Center

Discusses the historical development of the concept of geologic time. Develops the topic by using the major discoveries of geologists, beginning with Steno and following through to the discovery and use of radiometric dating. An extensive reference list is provided. (JM)

Albritton, Claude C., Jr.

1984-01-01

50

Geology Fulbrights  

NASA Astrophysics Data System (ADS)

Fulbright grants in geology for 1988-89 remain open. Specific opportunities are available in Egypt, German Democratic Republic, Hungary, Iceland, Iraq, Kuwait, Morocco, Mozambique, Oman, Poland, Sudan, Syria, Tanzania, Turkey, U.S.S.R., West Bank, Yemen, and Zimbabwe. Other countries are also open to applications in any discipline, and geology is among their preferred fields.The grants are available until awarded and are open only to U.S. citizens. In Central and South America and French-speaking Africa, knowledge of host-country language is required. For more information, contact the Council for International Exchange of Scholars (CIES), 11 Dupont Circle N.W., Suite 300, Washington, DC 20036; tel. 202-939-5401.

51

Physical Geology  

NSDL National Science Digital Library

This Tulane University course covers the nature of the Earth, the development of its surficial features, and the results of the interaction of chemical, physical, and biological factors on the planet. Lecture notes are about energy and minerals; igneous, metamorphic and sedimentary rocks; weathering and soils; geologic time; mass wasting; streams; groundwater; wind action and deserts; oceans; deformation of rock; earthquakes and the interior of the Earth; global tectonics; planetary changes; and glaciers.

Nelson, Stephen

52

Magnetic properties related to hydrothermal alteration processes at the Escondida porphyry copper deposit, northern Chile  

NASA Astrophysics Data System (ADS)

Fluid-rock interaction related to the circulation of hydrothermal fluids can strongly modify the physicochemical properties of wall rocks in porphyry Cu deposits. These processes can also produce compositional and textural changes in ferromagnetic minerals, which can be quantified using magnetic methods. In the Escondida porphyry Cu deposit of northern Chile, each hydrothermally altered lithology is characterized by a discrete assemblage of Fe-Ti oxide minerals. These minerals have distinctive bulk magnetic susceptibility (K bulk), temperature-dependent magnetic susceptibility, and magnetic hysteresis parameters. Selectively altered rocks (i.e., potassic and chloritic alteration types) exhibit the highest K bulk values (>3.93 × 10-3 SI units), and their hysteresis parameters indicate multidomain magnetic mineral behavior. This suggests that these rocks are composed of the coarsest magnetic grain sizes within the deposit. Optical analyses and susceptibility-temperature curves confirm that the magnetic signals in selectively altered rocks are mainly carried by secondary magnetite. In contrast, pervasively altered rocks (i.e., quartz-sericite and argillic alteration types) exhibit low K bulk values (<1.93 × 10-4 SI units) and contain smaller pseudo-single domain magnetic grain assemblages. This is consistent with the destruction and/or reduction in size of magnetite under acidic conditions. The results therefore demonstrate a genetic relationship between the hydrothermal alteration processes, Fe-Ti oxide minerals, and magnetic properties of the wall rock in the Escondida deposit. These magnetic methods can be considered a sensitive and efficient petrophysical tool for the identification and semi-quantification of alteration assemblages, and facilitating the recognition and mapping of discrete hydrothermal zones during exploration and operation of porphyry Cu deposits.

Riveros, K.; Veloso, E.; Campos, E.; Menzies, A.; Véliz, W.

2014-03-01

53

Geologic Time  

NSDL National Science Digital Library

This Classroom Connectors lesson plan discusses the characteristics of geologic time, including the law of superposition, fossil preservation, casts and molds, and various events through the history of the Earth. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

54

Hydrothermal alteration, ore fluid characteristics, and gold depositional processes along a trondhjemite-komatiite contact at Tarmoola, Western Australia  

USGS Publications Warehouse

Tarmoola is a structurally controlled Archean orogenic gold deposit hosted in greenschist facies metamorphosed komatiite and trondhjemite in the Leonora district of the Eastern Goldfields province, Yilgarn craton. High-grade (>1 g/t Au) orebodies are located in komatiite wall rock adjacent to the eastern and northeastern margins of the asymmetrical, north-south-striking, Tarmoola trondhjemite intrusion. Gold-bearing veins post-date trondhjemite emplacement (ca. 2700 Ma), quartz diorite dikes (ca. 2667 Ma), and regional greenschist facies metamorphism. Textures and crosscutting relationships in gold-bearing veins indicate two stages of hydrothermal fluid infiltration associated with a single gold-related hydrothermal event: a volumetrically dominant, but gold-poor, stage I fluid and a gold-rich stage II fluid. Gold-bearing veins contain stage I milky quartz and pyrite that are overprinted by stage II quartz-ankerite-muscovite-chalcopyrite-sphalerite-galena-gold-tellurides ?? albite ?? chlorite ?? fuchsite ?? epidote ?? scheelite. Stage I hydrothermal alteration assemblages are different in trondhjemite and komatiite due to contrasting reactions between a common ore fluid and disparate wall-rock chemistry. Stage II fluid-wall rock interaction was minor compared to stage I and is indicated by the overprinting of stage I mineral assemblages by stage II microveins. Wall-rock alteration proximal to veins in trondhjemite is characterized by replacement of igneous plagioclase, amphibole, biotite, and metamorphic chlorite by hydrothermal quartz, muscovite, ankerite, calcite, pyrite, chalcopyrite, sphalerite, galena, tellurides, and gold, whereas in proximal alteration in komatiite, metamorphic chlorite and talc are replaced by ankerite, quartz, muscovite, albite, chlorite, fuchsite, pyrite, chalcopyrite, sphalerite, galena, tellurides, and gold. The stage II fluid was enriched in H2O, CO2, Si, Ca, K, Na, S, Au, Ag, Cu, Pb, W, Bi, As, Mo, Zn, and Te. Based on fluid inclusion studies and stage II mineral equilibria, gold deposited from a homogeneous, neutral to slightly alkaline (pH 5.1-5.5), reduced, low-salinity (<5.5 wt % NaCl equiv) fluid that had a bulk composition of 78 mole percent H2O and 21 mole percent CO2, and trace amounts of CH4, C2H6, H2, Ar, H2S, and He. Gold deposition occurred at 300?? ?? 50??C and 0.5 to 3.0 kbars. Assuming lithostatic fluid pressures, gold precipitated at a 2- to 10-km depth. Stage II gray quartz ??18Ofluid values range from 5.9 to 7.5 per mil, whereas ??Dfluid values calculated from the dehydration of muscovite grains and measured directly from bulk fluid inclusion analyses of stage II gray quartz have ranges of -9 to -35 and -27 to -28 per mil, respectively. Hydrothermal ore fluids were transported from greater crustal depths to the site of gold deposition during the district-scale D3 event by shallowly W dipping, reverse brittle-ductile shear zones in supracrustal rock and along the steeply east dipping trondhjemite contact. Associated subhorizontal east-west shortening caused the reactivation of the eastern trondhjemite margin and subparallel foliation, which facilitated the transport of hydrothermal fluids and the generation of gold-bearing veins and hydrothermal alteration zones in komatiite. East-west-striking fractures in trondhjemite aided the lateral migration of ore fluids away from trondhjemite margins and the formation of east-west-striking gold-bearing veins and broad alteration zones. Gold was most likely transported in the stage II fluid as bisulfide complexes. The sulfidation of trondhjemite and komatiite wall rock by the stage II fluid caused the destabilization of An bisulfide complexes and gold deposition. Potassium, Ca, and CO2 metasomatism of komatiite wall rock may have enhanced gold deposition via the acidification of the stage II fluid. The physicochemical characteristics of the Tarmoola ore fluid and relative timing of gold mineralization are consistent with the Yilgarn-wide,

Duuring, P.; Hagemann, S. G.; Cassidy, K. F.; Johnson, C. A.

2004-01-01

55

Geology, geochemistry, and genesis of the Greens Creek massive sulfide deposit, Admiralty Island, southeastern Alaska  

USGS Publications Warehouse

In 1996, a memorandum of understanding was signed by representatives of the U.S. Geological Survey and Kennecott Greens Creek Mining Company to initiate a cooperative applied research project focused on the Greens Creek massive sulfide deposit in southeastern Alaska. The goals of the project were consistent with the mandate of the U.S. Geological Survey Mineral Resources Program to maintain a leading role in national mineral deposits research and with the need of Kennecott Greens Creek Mining Company to further development of the Greens Creek deposit and similar deposits in Alaska and elsewhere. The memorandum enumerated four main research priorities: (1) characterization of protoliths for the wall rocks, and elucidation of their alteration histories, (2) determination of the ore mineralogy and paragenesis, including metal residences and metal zonation within the deposit, (3) determination of the ages of events important to ore formation using both geochronology and paleontology, and (4) development of computer models that would allow the deposit and its host rocks to be examined in detail in three dimensions. The work was carried out by numerous scientists of diverse expertise over a period of several years. The written results, which are contained in this Professional Paper, are presented by 21 authors: 13 from the U.S. Geological Survey, 4 from Kennecott Greens Creek Mining Company, 2 from academia, and 2 from consultants. The Greens Creek deposit (global resource of 24.2 million tons at an average grade of 13.9 percent zinc, 5.1 percent lead, 0.15 troy ounce per ton gold, and 19.2 troy ounces per ton silver at zero cutoff) formed in latest Triassic time during a brief period of rifting of the Alexander terrane. The deposit exhibits a range of syngenetic, diagenetic, and epigenetic features that are typical of volcanogenic (VMS), sedimentary exhalative (SEDEX), and Mississippi Valley-type (MVT) genetic models. In the earliest stages of rifting, formation of precious-metal-rich silica-barite-carbonate white ores began at low temperature in a shallow, subaqueous setting, probably a thin carbonate shelf on the flanks of the Alexander landmass. Epigenetic carbonate replacement textures in the footwall dolostones are overlain by stratiform silica-carbonate-barite-rich ores and indicate that early mineralization formed at and just beneath the paleo sea floor by mixing of a reduced, precious-metal-rich, base-metal-poor hydrothermal fluid with oxygenated seawater. As rifting intensified, the shelf was downfaulted and isolated as a graben. Isolation of the basin and onset of starved-basin shale sedimentation was concurrent with emplacement of mafic-ultramafic intrusives at shallow levels in the rift, resulting in an increasingly higher temperature and progressively more anoxic ore-forming environment. The formation of the main stage of massive sulfide ores began as the supply of bacterially reduced sulfur increased in the accumulating shales. As the main-stage mineralization intensified, shale sedimentation inundated the hydrothermal system, eventually forming a cap. Biogenic sulfate reduction supplied reduced sulfur to the base of the shales where mixing occurred with hot, base-metal-rich hydrothermal fluids. Ore deposition continued by destruction and epigenetic replacement of the early white ores in proximal areas and by inflation and diagenetic replacement of unlithified shale at the interface between the white ores and the base of the shale cap. Ore deposition waned as the shales became lithified and as the supply of bacterially reduced sulfur to the site of ore deposition ceased. The final stages of rifting resulted in the emplacement of mafic-ultramafic intrusive rocks into the Greens Creek system and extrusion of voluminous basaltic flows at the top of the Triassic section. Greenschist facies metamorphism during the Jurassic-Cretaceous accretion of the Alexander terrane to the continental margin resulted in recrystalli

Taylor, Cliff D.; Johnson, Craig A.

2010-01-01

56

Illinois State Geological Survey  

NSDL National Science Digital Library

The Illinois State Geological Survey (ISGS) homepage provides information on geologic mapping, earthquakes, fossils, groundwater, wetlands, glacial geology, bedrock geology, and Lake Michigan geology. Educational materials include field trip guides, short publications on Illinois geology for students and teachers, online tours, single-page maps, and a geologic column. Other materials include databases and collections of GIS data, well records, drill cores, and mining information; a bibliography of Illinois geology; online maps and data; and information on water and land use, resource development, and geologic hazards.

57

Geology of California  

SciTech Connect

This book reviews some of the basic principles of geology and includes a chapter on the Klamath Mountains. Chapters cover the geologic history of California and the geologic features of the various deserts, mountain ranges, plateaus, basins, and valleys of the state, including offshore geology and the San Andreas fault. The authors discuss exotic and suspect terranes, and current theories concerning California geology.

Norris, R.M.; Webb, R.W.

1990-01-01

58

Geologic Technician New Curriculum  

ERIC Educational Resources Information Center

Describes a developing two-year geologic technician program at Bakersfield College in which a student may major in five areas - geologic drafting, land and legal, geologic assistant, engineering or paleontology. (RR)

Karp, Stanley E.

1970-01-01

59

Geological Time Scale  

NSDL National Science Digital Library

This document describes how geologic time is approached in discussions of geologic topics. The uses of relative time and absolute time are compared, and a geologic time scale is provided to represent both concepts. References are provided.

60

Geologic Mapping on Mars  

NSDL National Science Digital Library

This lab is part of a Lunar and Planetary Geology course offered to both geology and non-geology majors, and it involves basic geological mapping of an area within the Tyrrhena Patera region on Mars. Students are encouraged to work in groups to prepare a geological map from a photomosaic map and to interpret the geologic stratigraphy from a geological map of the greater area. This activity reinforces mapping skills as well as group work skills, and aims to teach students more about Martian stratigraphy and geology through a hands-on activity.

De Villiers, Germari

61

Alteration and geochemical zoning in Bodie Bluff, Bodie mining district, eastern California  

USGS Publications Warehouse

Banded, epithermal quartz-adularia veins have produced about 1.5 million ounces of gold and 7 million ounces of silver from the Bodie mining district, eastern California. The veins cut dacitic lava flows, pyroclastic rocks and intrusions. Sinter boulders occur in a graben structure at the top of Bodie Bluff and fragments of sinter and mineralized quartz veins occur in hydrothermal breccias nearby. Explosive venting evidently was part of the evolution of the ore-forming geothermal systems which, at one time, must had reached the paleosurface. Previous reconnaissance studies at Bodie Bluff suggested that the geometry of alteration mineral assemblages and distribution of some of the major and trace elements throughout the system correspond to those predicted by models of hot-spring, volcanic rock hosted precious metal deposits (Silberman, 1982; Silberman and Berger, 1985). The current study was undertaken to evaluate these sugestions further. About 500 samples of quartz veins and altered rocks, including sinter, collected over a vertical extent of 200 meters within Bodie Bluff were petrographically examined and chemically analyzed for trace elements by emission spectrographic and atomic absorption methods. Sixty-five samples were analyzed for major elements by X-ray fluorescence methods. The results of these analyses showed that, in general, alteration mineral assemblage and vertical geochemical zoning patterns follow those predicted for hot-spring deposits, but that geochemical zoning patterns for sinter and quartz veins (siliceous deposits), and altered wall rocks are not always similar. The predicted depth-concentration patterns for some elements, notably Au, Ag, Hg, and Tl in quartz veins, and Hg, As and Ag in wall rocks were not as expected, or were perturbed by the main ore producing zone. For both quartz veins and altered wall rocks, the main ore zone had elevated metal contents. Increased concentration of many of these elements could indicate proximity to this zone. However, irregularities in the distribution of some key elements, such as Au and Ag, relative to the predictive models suggest that a larger suite of elements be considered for exploration for ore zones within the district. ?? 1993.

Herrera, P. A.; Closs, L. G.; Silberman, M. L.

1993-01-01

62

Digital Geology of Idaho  

NSDL National Science Digital Library

This online course systematically divides Idaho geology into 15 individual teaching modules which correspond with a two-credit, 15-week classroom course. Each module covers a specific area or type of geology in the state of Idaho. Topics include geology of basement rocks, rocks and geology of the Belt Supergroup, tectonic regimes, and geologic history. There are also modules on rocks and geology of the Idaho Batholith, volcanic history and deposits of the Snake River Plain and Columbia Plateau, and Pleistocene glaciation and floods from Lakes Missoula and Bonneville. Each of the modules provides geologic maps from a recently developed Geologic Map of Idaho, produced by the Idaho Geological Survey, and most also feature fly-throughs in which geologic information is draped over topography to provide visualizations of the geology along Idaho rivers.

63

Colorado Geological Survey  

NSDL National Science Digital Library

The Colorado Geological Survey (CGS) is an agency of state government within the Department of Natural Resources whose mission is to help reduce the impact of geologic hazards on the citizens of Colorado, to promote the responsible economic development of mineral and mineral fuel resources, to provide geologic insight into water resources, and to provide geologic advice and information to a variety of constituencies. This site contains extensive information about Colorado geology such as maps, a geologic time scale for the state, program information, and state field trip information. This site hosts the Avalanche Information Center which contains avalanche forecasting and education center details. Publications report on geologic hazards, land use, environmental geology, mineral resources, oil, gas, coal, geologic mapping and earthquake information for the state. There are online editions of RockTalk, which is a quarterly newsletter published by the Colorado Geological Survey dealing with all aspects of geology throughout the state of Colorado. Links are provided for more resources.

64

Maryland Geological Survey  

NSDL National Science Digital Library

The Maryland Geological Survey (MGS) homepage contains information from MGS programs on hydrogeology, hydrology, coastal and estuarine geology, environmental geology and mineral resources; an online guide to Maryland geology; and information on oyster habitat restoration projects. There are also maps, data, information on MGS publications, MGS news, and online educational resources.

65

Geologic Maps and Mapping  

NSDL National Science Digital Library

This portal provides access to resources on geologic mapping, and to sources of geologic maps. There is an introduction to geologic mapping, which summarizes its principles and practices, and a history of United States Geological Survey (USGS) mapping activities from 1879 to the present, as well as links to papers on the values and hazards associated with geologic maps and mapping. Online sources of maps include the USGS Geologic Map Database, other federal map products (FEDMAP), state geological survey products (STATEMAP), and university map products (EDMAP).

66

Kentucky Geological Survey  

NSDL National Science Digital Library

The University of Kentucky maintains the Kentucky Geological Survey Web site. Visitors will find a number of educational general information pages on rocks and minerals, fossils, coal, geologic hazards, industrial minerals, maps and GIS, oil and natural gas, and water, as well as the general geology of Kentucky. Each page contains specific information, data, and research summaries from the university. The geology of Kentucky page, for example, shows a map of geologic periods and gives descriptions of the rock strata in the state, a description of its landforms, and a geological photo album of physiographic regions and points of interest.

1997-01-01

67

Glossary of Geologic Terms  

NSDL National Science Digital Library

This page from Iowa State University presents a general glossary of geologic terms. The site would be a good reference for geology coursework. This glossary of geologic terms is based on the glossary in Earth: An Introduction to Geologic Change, by S. Judson and S.M. Richardson (Englewood Cliffs, NJ, Prentice Hall, 1995). Where possible, definitions conform generally, and in some cases specifically, to definitions given in Robert L Bates and Julia A Jackson (editors), Glossary of Geology, 3rd ed., American Geological Institute, Alexandria, Virginia, 1987.

2011-07-18

68

Geologic spatial analysis  

SciTech Connect

This report describes the development of geologic spatial analysis research which focuses on conducting comprehensive three-dimensional analysis of regions using geologic data sets that can be referenced by latitude, longitude, and elevation/depth. (CBS)

Thiessen, R.L.; Eliason, J.R.

1989-01-01

69

GSA Geologic Time Scale  

NSDL National Science Digital Library

This Geological Society of America (GSA) site contains a detailed geologic time scale as an educational resource. It may be downloaded to a larger size, and includes all Eras, Eons, Periods, Epochs and ages as well as magnetic polarity information.

1999-01-01

70

Geophysics & Geology Inspected.  

ERIC Educational Resources Information Center

Summarizes findings of a recently published report of the Canadian Geoscience Council, which includes the following topics regarding college geology: facilities; teaching; undergraduate enrollments; postgraduate enrollments; geologic research; and integration of Canadian geoscience with other countries. (CS)

Neale, E. R. W.

1981-01-01

71

What is Geologic Time?  

NSDL National Science Digital Library

This USGS site employs graphics and text to explain geological time. The different geological eons, eras, epochs and periods are defined and put into perspective. The site also provides links to many terms and concepts for further exploration.

Usgs

72

South Carolina Geological Survey  

NSDL National Science Digital Library

The South Carolina Geological Survey (SCGS) homepage contains information about state mapping, education and outreach programs, and recent news. For educators, there is the Earth Science education series of publications which includes presentations and page-size graphics on such topics as earthquakes, plate tectonics, geologic time, fossils, and others. Other materials include information on mineral resources, links to organizations in and about South Carolina geology, the South Carolina core repository, the Geologic Map of South Carolina, and others.

73

Iowa Geological Survey Bureau  

NSDL National Science Digital Library

The Iowa Geological Survey Bureau (GSB) homepage contains: general information about the geology of Iowa; the Natural Resources Geographic Information System, which is a collection of databases on geology and water wells; and information about GSB staff, geologic studies, water monitoring programs, and services. There are maps, photographs, general interest articles, technical abstracts, lists of available publications, and an on-line book about the natural resource history of Iowa.

74

Geological Survey Program  

NSDL National Science Digital Library

If your research or interests lie in the geology of South Dakota, then the state's Geological Survey Program Web site is for you. Offered are online publications and maps, a geologic reference database, a lithologic logs database, digital base maps, a water quality database, and several other quality information sources worth checking out.

75

Arkansas Geological Survey  

NSDL National Science Digital Library

The Arkansas Geological Survey (AGS) homepage aims to develop and provide knowledge of the geology and hydrogeology of the State, and to stimulate development and effective management and utilization of the mineral, fossil-fuel, and water resources of Arkansas while protecting the environment. The AGC collects and disperses geologic data consisting of geologic maps, historical data concerning resources, and various datasets concerning water, fossil-fuel, and mineral resources of Arkansas. The site contains publications that can be ordered, sections about Arkansas geology, a list of mineral producers of Arkansas, and reports on mineral resources.

76

Virtual-Geology.Info  

NSDL National Science Digital Library

At virtual-geology.info, Roger Suthren, a professor at Oxford Brookes University, offers educational materials on geologic phenomena throughout the world. Users can take virtual field trips to study the geology of Scotland, Alaska, and France. In the Regional Geology link, visitors can view wonderful pictures of the volcanoes of Germany, Italy, France, and Greece. Educators can find images of sediments and sedimentary rocks which can be used in a variety of classroom exercises. The website supplies descriptions and additional educational links about sedimentology and environmental geology.

77

Geology of Kentucky  

NSDL National Science Digital Library

This website contains geologic maps of Kentucky, with a discussion of geologic time in regards to the rocks, minerals, fossils, and economic deposits found there. There are also sections that describe strata and geologic structures beneath the surface (faults, basins, and arches), the structural processes (folding and faulting) that create stratigraphic units, the geomorphology of the state, geologic information by county, a general description of geologic time, fossil, rocks, and minerals of Kentucky, and a virtual field trip through Natural Bridges State Park. Links are provided for further information.

78

Utah Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Utah Geological Survey. Materials available here include news articles and information on geologic hazards; information on places of geological interest; and popular geology topics such as earthquakes, rocks and minerals, fossils, economic resources, groundwater resources, and others. Educational resources include teaching kits, the 'Teacher's Corner' column in the survey's newsletter, and a series of 'Glad You Asked' articles on state geological topics. There is also an extensive list of free K-12 educational materials, as well as a set of curriculum materials such as activity packets, slide shows, and teachers' handbooks, which are available to order.

79

Ohio Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Ohio Geological Survey. Materials available through the site include a variety of publications, particularly the Survey's reports, bulletins, information circulars, guidebooks, and many others. There is an extensive selection of maps, including topographic maps in several scales, and downloadable geologic maps of several themes (drift thickness, bedrock geology, karst areas, glacial geology, and many others), as well as digital maps and data. The interactive maps section features online map viewers of abandoned mines, earthquake epicenters, surficial geology, geology of Lake Erie, and others. The educational resources page has links to the 'Hands On Earth' series of activities, GeoFacts (short bulletins on Ohio geological topics), nontechnical educational leaflets, field guides, and links to other publications, rock and mineral clubs, educational associations, and related websites. There is also a link to the Ohio Seismic Network, a network of seismograph stations located at colleges, universities, and other institutions that collects and disseminates information about earthquakes in Ohio.

80

Kansas Geological Survey  

NSDL National Science Digital Library

The mission of the Kansas Geological Survey, operated by the University of Kansas in connection with its research and service program, is to conduct geological studies and research and to collect, correlate, preserve, and disseminate information leading to a better understanding of the geology of Kansas, with special emphasis on natural resources of economic value, water quality and quantity, and geologic hazards. The website includes information about the High Plains and Ogallala aquifers, the Upper Arkansas corridor, the Dakota aquifer, county and state geologic maps, an online bibliography of Kansas geology, publications, a photo archive, a digital petroleum atlas, a petroleum primer for the state, gravity and magnetic maps, Hugoton project information, and details about the Hutchinson Kansas natural gas fires. The educational resources section contains a mineral information page for the state, and GeoKansas, which provides information on state geology for schools.

81

Geologic Time: Online Edition  

NSDL National Science Digital Library

Offered by the United States Geological Survey (USGS) as a general interest publication, this site is an online edition of a text by the same name, offering a concise overview of the concepts associated with the age of the Earth. The online edition was revised in October of 1997 to reflect current thinking on this topic. Section headers are Geologic Time, Relative Time Scale, Major Divisions of Geologic Time, Index Fossils, Radiometric Time Scale, and Age of the Earth.

1997-10-09

82

Sedimentology and petroleum geology  

SciTech Connect

This book presents an introduction to sedimentology as well as petroleum geology. It integrates both subjects, which are closely related but mostly treated separately. The author covers the basic aspects of sedimentology, sedimentary geochemistry and diagenesis. Principles of stratigraphy, seismic stratigraphy and basin modelling forms the base for the part on petroleum geology. Subjects discussed include the composition of kerogen and hydrocarbons, theories of migration and trapping of hydrocarbons and properties of reservoir rocks. Introductions to well logging and production geology are given.

Bjorlykke, K.O. (Oslo Univ. (Norway))

1989-01-01

83

Image Gallery for Geology  

NSDL National Science Digital Library

These images of geologic phenomena are used to supplement introductory geology classes at the University of North Carolina at Chapel Hill. The images are categorized under plutonic, volcanic and sedimentary rocks; structural geology; weathering; and coastlines. There are photographs of different kinds of volcanoes; lavas and pyroclastic rocks; volcanic hazards; different types of sedimentary rocks and sedimentary structures; folds and faults; beach processes; and barrier islands.

Glazner, Allen

84

North Carolina Geological Survey  

NSDL National Science Digital Library

The North Carolina Geological Survey (NCGS) examines, describes, and maps the state's geology and mineral resources and publishes reports and maps. The site contains lists of publications, maps, aerial photographs, frequently asked questions about North Carolina geology, and mineral and professional information. Project Earth Science is designed to provide relevant and accurate earth science education information for the state's high school students and earth/environmental science teachers.

85

Geologic Mapping Exercise  

NSDL National Science Digital Library

This exercise is designed to simulate how a basic geological investigation of a site takes place. A basic geological investigation includes familiarizing yourself with the unconsolidated sediments, rocks, structural geology, and groundwater present at your site. As part of this exercise you will have to properly identify a variety of rock types and sediments, create maps that represent data you collected at each location, and complete a basic report of your findings (optional). Once completed, this exercise should give students a basic understanding of how the various concepts used throughout the semester are applied in the real world in the form of a geological investigation.

Smith, Andrew

86

Geology explorer: virtual geologic mapping and interpretation  

NASA Astrophysics Data System (ADS)

We are developing internet-based freeware for virtual mapping and geologic interpretation. This takes the form of a synthetic, virtual world, Planet Oit, where students are given the means and the equipment to carry out geologic investigation and interpretation as a geologist would in the field. The environment is designed to give students an authentic experience that includes elements of: (1) exploration of a spatially oriented, virtual, world; (2) practical, field oriented, expedition planning and decision-making; and (3) scientific problem solving (i.e. a "hands on" approach to mapping, geologic investigation, data acquisition, and interpretation). The game-like environment is networked, multi-player, and simulation-based. Planet Oit can be visited on the Internet at http://oit.cs.ndsu.nodak.edu/

Saini-Eidukat, Bernhardt; Schwert, Donald P.; Slator, Brian M.

2002-12-01

87

The Geological Society of London  

NSDL National Science Digital Library

The Geological Society of London promotes "the geosciences and the professional interests of UK geoscientists." The website offers media, geological, and society news. Researchers can find out about upcoming conferences covering a variety of geological topics as well as information on a series of journals. Everyone interested in geology can find materials on geological careers, including required education, qualifications, and funding. The website provides teaching resources on volcanoes, geologic hazards, and other geological phenomena.

88

California Geological Survey - Landslides  

NSDL National Science Digital Library

This page from the CA Geological Survey (CGS) presents information on landslides as well as maps and products of various past and present CGS programs to map and respond to landslides in the state of California, including the Forest and Watershed Geology Program, the Seismic Hazards Zonation Program, the Caltrans Highway Corridor Mapping project, and the Landslide Map Index.

Survey, California G.

89

External Resource: Geologic Time  

NSDL National Science Digital Library

This NASA sponsored webpage, Center for Educational Technologies, teaches students about Geologic Time. The age of Earth is so long compared to all periods of time that we humans are familiar with, it has been given a special name: Geologic time. The age

1900-01-01

90

Interpreting Urban Geology.  

ERIC Educational Resources Information Center

Describes field trips to urban locations for geological instruction. The program was developed by the Cleveland Museum of Natural History. Authors claim these field trips have been an effective and enjoyable way of conveying a wide variety of geological information to participants at all levels and backgrounds and have created favorable publicity.…

Hannibal, Joseph Timothy; Schmidt, Mark Thomas

1991-01-01

91

Marine Geological Discoveries  

NSDL National Science Digital Library

This site by a Norwegian researcher features descriptions of marine geological formations: pockmarks, mud volcanoes, deep-water coral reefs, and gas hydrates. Using ROV technology, he has taken photos of these deep seafloor features, and compares them to geological structures seen on land, and even on the moon.

Hovland, Martin

2010-12-28

92

National Geologic Map Database  

NSDL National Science Digital Library

The National Geologic Map Database (NGMDB) is an Internet-based system for query and retrieval of earth-science map information, created as a collaborative effort between the USGS and the Association of American State Geologists. Its functions include providing a catalog of available map information; a data repository; and a source for general information on the nature and intended uses of the various types of earth-science information. The map catalog is a comprehensive, searchable catalog of all geoscience maps of the United States, in paper or digital format. It includes maps published in geological survey formal series and open-file series, maps in books, theses and dissertations, maps published by park associations, scientific societies, and other agencies, as well as publications that do not contain a map but instead provide a geological description of an area (for example, a state park). The geologic-names lexicon (GEOLEX) is a search tool for lithologic and geochronologic unit names. It now contains roughly 90% of the geologic names found in the most recent listing of USGS-approved geologic names. Current mapping activities at 1:24,000- and 1:100,000-scale are listed in the Geologic Mapping in Progress Database. Information on how to find topographic maps and list of geology-related links is also available.

1997-01-01

93

Radiometric Dating in Geology.  

ERIC Educational Resources Information Center

Described are several aspects and methods of quantitatively measuring geologic time using a constant-rate natural process of radioactive decay. Topics include half lives and decay constants, radiogenic growth, potassium-argon dating, rubidium-strontium dating, and the role of geochronology in support of geological exploration. (DS)

Pankhurst, R. J.

1980-01-01

94

Geological Time Machine  

NSDL National Science Digital Library

Ride the Web Geological Time Machine at the University of California Museum of Paleontology. Click on an item in the list of 25 geological periods [15 of the 25 periods are available now, the remainder to be completed] and view a page describing each period, its subdivisions, and the life and fossils of that period.

Collins, Allen.

1997-01-01

95

Geologic time scale bookmark  

USGS Publications Warehouse

This bookmark, designed for use with U.S. Geological Survey activities at the 2nd USA Science and Engineering Festival (April 26–29, 2012), is adapted from the more detailed Fact Sheet 2010–3059 "Divisions of Geologic Time." The information that it presents is widely sought by educators and students.

U.S. Geological Survey

2012-01-01

96

Layer Cake Geology  

NSDL National Science Digital Library

This classroom activity uses a cake to demonstrate geologic processes and introduce geologic terms. Students will learn how folds and faults occur, recognize the difference in behavior between brittle and ductile rocks, and attempt to predict structures likely to result from application of various forces to layered rocks. They will also attempt to interpret 'core samples' to determine subsurface rock structure.

Wagner, John

97

Radiometric dating in geology  

Microsoft Academic Search

The method of dating rocks and minerals is known as geochronology. Although in principle this term could be applied to estimation of relative ages according to traditional geological observation, it is nowadays usually restricted to the quantitative measurement of geological time using the constant-rate natural process of radioactive decay. 14C dating is a technique based on measuring the residual radioactivity

R J Pankhurst

1980-01-01

98

People and Geology.  

ERIC Educational Resources Information Center

Provides background information on the many natural resources we extract from the earth's crust, including metals, graphite, and other minerals, as well as fossil fuels. Contains teaching activities such as a geologic scavenger hunt, a geology chronology, and the recycling of aluminum. Includes a reproducible handout for the activity on aluminum.…

Naturescope, 1987

1987-01-01

99

Geologic mapping of Europa  

Microsoft Academic Search

Galileo data enable the major geological units, structures, and surface features to be identified on Europa. These include five primary units (plains, chaos, band, ridge, and crater materials) and their subunits, along with various tectonic structures such as faults. Plains units are the most widespread. Ridged plains material spans a wide range of geological ages, including the oldest recognizable features

Ronald Greeley; Patricio H. Figueredo; David A. Williams; Frank C. Chuang; James E. Klemaszewski; Steven D. Kadel; Louise M. Prockter; Robert T. Pappalardo; James W. Head; Geoffrey C. Collins; Nicole A. Spaun; Robert J. Sullivan; Jeffrey M. Moore; David A. Senske; B. Randall Tufts; Torrence V. Johnson; Michael J. S. Belton; Kenneth L. Tanaka

2000-01-01

100

Glossary of geology  

SciTech Connect

This third edition of the Glossary of Geology contains approximately 37,000 terms, or 1,000 more than the second edition. New entries are especially numerous in the fields of carbonate sedimentology, hydrogeology, marine geology, mineralogy, ore deposits, plate tectonics, snow and ice, and stratigraphic nomenclature. Many of the definitions provide background information.

Bates, R.L.; Jackson, J.A.

1987-01-01

101

Geologic Time Online Edition  

NSDL National Science Digital Library

This tutorial will help students learn and understand the concepts of geologic time and the age of the Earth. They will investigate the geologic time scale and learn about the use of index fossils and radiometric dating to determine the age of rock formations and fossils.

102

Structural Geology Techniques  

NSDL National Science Digital Library

The University of Wisconsin - Green Bay has created this collection of material and instructions on how to analyze and plot structural geology data. Topics covered includes planes, lines, relations between lines and planes, geologic structures, intersection of structures with topography, stereonet techniques, stress and strain, and analysis of complex structures.

Dutch, Steven

2009-05-21

103

Advances in planetary geology  

NASA Technical Reports Server (NTRS)

This second issue in a new series intended to serve the planetary geology community with a form for quick and thorough communications includes (1) a catalog of terrestrial craterform structures for northern Europe; (2) abstracts of results of the Planetary Geology Program, and (3) a list of the photographic holdings of regional planetary image facilities.

Woronow, A. (editor)

1981-01-01

104

Geologic remote sensing  

USGS Publications Warehouse

Remote-sensing techniques are now being used routinely in geologic interpretation for mineral and energy exploration, plant siting, waste disposal, and the development of models for regional and continental tectonics. New spaceborne methods and associated technologies are being developed to produce data from which geologic information about large areas can be derived much more rapidly than by conventional techniques. Copyright ?? 1981 AAAS.

Goetz, A. F. H.; Rowan, L. C.

1981-01-01

105

Women in Early Geology.  

ERIC Educational Resources Information Center

Biographical sketches are given for several women who made early contributions to the science of geology. A short biography of Inge Lehmann is also included as a more recent example of a woman who has made a notable contribution to the geological field. (Author)

Elder, Eleanor S.

1982-01-01

106

Earthquakes and Geology  

NSDL National Science Digital Library

In this activity, students investigate the relationship between intensity of ground motion and type of rock or alluvium, as seen in the 1994 Northridge, California earthquake. They will examine a map of Mercalli intensity, a cross-section showing geologic structures and rock types, and a map of surficial geology, and answer questions pertaining to amplification of ground motion and S-wave velocities.

Ozsvath, David

2011-09-06

107

British Geological Survey: Learning  

NSDL National Science Digital Library

The British Geological Survey (BGS) has a wealth of information about the earth sciences, and they are quite willing to share it with others. This page contains information and resources for anyone interested in geology for educational or leisure purposes, and it is contained with four sections. First up is "Popular geology", which includes "Britain beneath our feet", an interactive atlas of geology, resources, and land quality. This section also contains graphics about climate change and earthquakes. The second section is titled "Educational resources". Here visitors can ask scientists at the BGS specific questions and they can also download several free posters. The third section is called "Educational news and events" and it features upcoming events at the BGS and links to their free magazine, "Earthwise". The site is rounded out by the fourth section titled "From the BGS Archives". Here visitors can view historic geological photographs and also view field sketches and watercolors by Alexander Henry Green, the celebrated Victorian geologist.

108

Deterministic geologic processes and stochastic modeling  

SciTech Connect

Recent outcrop sampling at Yucca Mountain, Nevada, has produced significant new information regarding the distribution of physical properties at the site of a potential high-level nuclear waste repository. Consideration of the spatial distribution of measured values and geostatistical measures of spatial variability indicates that there are a number of widespread deterministic geologic features at the site that have important implications for numerical modeling of such performance aspects as ground water flow and radionuclide transport. These deterministic features have their origin in the complex, yet logical, interplay of a number of deterministic geologic processes, including magmatic evolution; volcanic eruption, transport, and emplacement; post-emplacement cooling and alteration; and late-stage (diagenetic) alteration. Because of geologic processes responsible for formation of Yucca Mountain are relatively well understood and operate on a more-or-less regional scale, understanding of these processes can be used in modeling the physical properties and performance of the site. Information reflecting these deterministic geologic processes may be incorporated into the modeling program explicitly, using geostatistical concepts such as soft information, or implicitly, through the adoption of a particular approach to modeling. It is unlikely that any single representation of physical properties at the site will be suitable for all modeling purposes. Instead, the same underlying physical reality will need to be described many times, each in a manner conducive to assessing specific performance issues.

Rautman, C.A. [Sandia National Labs., Albuquerque, NM (United States); Flint, A.L. [Geological Survey, Mercury, NV (United States)

1991-12-31

109

Essential Elements of Geologic Reports.  

ERIC Educational Resources Information Center

Described is a report outline for geologic reports. Essential elements include title; abstract; introduction; stratigraphy; petrography; geochemistry; petrology; geophysics; structural geology; geologic history; modeling; economics; conclusions; and recommendations. (Author/CW)

Webb, Elmer James

1988-01-01

110

Virtual Tour of Maine Geology  

NSDL National Science Digital Library

This selection of slide shows provides a photographic tour of Maine geology. Users can choose slide shows on surficial, bedrock, and coastal geology; fossils, geologic hazards, groundwater and wells; or mineral collecting, mining, and quarrying.

111

Fundamentals of Structural Geology  

NASA Astrophysics Data System (ADS)

Fundamentals of Structural Geology provides a new framework for the investigation of geological structures by integrating field mapping and mechanical analysis. Assuming a basic knowledge of physical geology, introductory calculus and physics, it emphasizes the observational data, modern mapping technology, principles of continuum mechanics, and the mathematical and computational skills, necessary to quantitatively map, describe, model, and explain deformation in Earth's lithosphere. By starting from the fundamental conservation laws of mass and momentum, the constitutive laws of material behavior, and the kinematic relationships for strain and rate of deformation, the authors demonstrate the relevance of solid and fluid mechanics to structural geology. This book offers a modern quantitative approach to structural geology for advanced students and researchers in structural geology and tectonics. It is supported by a website hosting images from the book, additional colour images, student exercises and MATLAB scripts. Solutions to the exercises are available to instructors. The book integrates field mapping using modern technology with the analysis of structures based on a complete mechanics MATLAB is used to visualize physical fields and analytical results and MATLAB scripts can be downloaded from the website to recreate textbook graphics and enable students to explore their choice of parameters and boundary conditions The supplementary website hosts color images of outcrop photographs used in the text, supplementary color images, and images of textbook figures for classroom presentations The textbook website also includes student exercises designed to instill the fundamental relationships, and to encourage the visualization of the evolution of geological structures; solutions are available to instructors

Pollard, David D.; Fletcher, Raymond C.

2005-09-01

112

DNA ALTERATIONS  

EPA Science Inventory

The exposure of an organism to genotoxic chemicals may induce a cascade of genetic events. nitially, structural alterations to DNA are formed. ext, the DNA damage is processed and subsequently expressed in mutant gene products. inally, diseases result from the genetic damage. he ...

113

Formation evaluation: Geological procedures  

SciTech Connect

This volume goes beyond a discussion of petroleum geology and the techniques of hydrocarbon (oil and gas) logging as a reservoir evaluation tool. It provides the logging geologist with a review of geological techniques and classification systems that will ensure the maximum development of communicable geological information. Contents include: 1. Introduction--cuttings recovery, cutting sampling, core sampling, rock classification; 2. Detrital rocks--classification, description; 3. Carbonate rocks--classification, description; 4. Chemical rocks-introduction, siliceous rocks, ferruginous rocks, aluminous rocks, phosphatic rocks, aluminous rocks, carbonaceous rocks; 5. Igneous and metamorpbic rocks; Appendix; References and Index.

Whittaker, A.

1985-01-01

114

Geology of caves  

USGS Publications Warehouse

A cave is a natural opening in the ground extending beyond the zone of light and large enough to permit the entry of man. Occurring in a wide variety of rock types and caused by widely differing geological processes, caves range in size from single small rooms to intercorinecting passages many miles long. The scientific study of caves is called speleology (from the Greek words spelaion for cave and logos for study). It is a composite science based on geology, hydrology, biology, and archaeology, and thus holds special interest for earth scientists of the U.S. Geological Survey.

Morgan, I. M., Davies, W. E.

1991-01-01

115

Sand Sea Wonders: Geology  

NSDL National Science Digital Library

This site describes the geology of The Great Sand Dunes National Monument and Preserve. Active links allow students to explore the geologic timeline, geologic cross section in animation, and the wind regime. A reversing dune is shown in animation and other dunes such as star, parabolic, barchan, and transverse are discussed. Another section illustrates sand recycling by seasonal streams. A sand deposits map shows topography, dunes watershed, old national monument boundary, roads, and surface water and a section called 'How Much Sand' quantifies the description. Artwork on this site includes both adult and 'Hands on the Land' student artwork while photography depicts dunes, landscape, animals, plants, and human history.

116

Indiana Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Indiana Geological Survey (IGS). Site materials include information on Earth science issues such as groundwater, mapping, coal and mineral resources, oil and gas, and seismic hazards. There is also information on the geologic time scale and stratigraphic record, rocks and minerals, fossils (including nautiloids of the Ordovician period in Indiana), caves and karst topography in Indiana, and glacial geology. The Geographic Information Ssytems (GIS) and mapping section includes a GIS atlas for the state, an online map viewer, links to the Indiana coal mine information system, petroleum database management system, and a download page where users can access GIS datasets for the state.

117

What is Geologic Time?  

NSDL National Science Digital Library

This webpage of the National Park Service (NPS) and United States Geological Survey (USGS) discusses geologic time and what it represents. Beginning about 4.6 billion years ago and ending in the present day, this site exhibits (to scale) the various eras, periods, eons, and epochs of Earth's history with a downloadable geologic time scale available. Links provide maps of what the Earth looked like at various times in its history, as well as a description of how scientists developed the time scale and how they know the age of the Earth.

118

Florida Geological Survey  

NSDL National Science Digital Library

The Florida Geological Survey (FGS) homepage provides data, research materials and interpretations on aquifer systems, geologic frameworks, landforms, energy and non-energy mineral resources, and geologic hazards which which can be used to address issues of conservation and protection, sustainable development, human health protection, and implementation of successful environmental regulatory programs. Educational materials for earth science and the pre-historic development of the state are also provided. These include topics such as sinkholes, data and maps, rock and mineral identification, minerals, hydrogeology, and fossils.

119

Journal of Geology  

NSDL National Science Digital Library

From the University of Chicago Press's Journals Division, the Journal of Geology is currently available online free of charge (note: subscription fees may soon apply, but no initiation date is provided). This first-rate technical journal, which publishes "research and theory in geophysics, geochemistry, sedimentology, geomorphology, petrology, plate tectonics, volcanology, structural geology, mineralogy, and planetary sciences" has been in print form since 1893. All of the 1999 issues of the Journal of Geology electronic edition are available here. Internet users can access full-text articles with internal links to references and figures (html, .pdf. .ps).

120

Thermohydrology of fractured geologic materials  

NASA Astrophysics Data System (ADS)

Thermohydrological and thermohydrochemical modeling as applied to the disposal of radioactive materials in a geologic repository is presented. Site hydrology, chemistry, and mineralogy were summarized and conceptual models of the fundamental system processes were developed. The numerical model TOUGH2 was used to complete computer simulations of thermohydrological processes in fractured, geologic media. Sensitivity studies investigating the impact of dimensionality and different conceptual models to represent fractures (ECM, DK, MINC) on thermohydrological response were developed. Sensitivity to parameter variation within a given conceptual model was also considered. The sensitivity of response was examined against thermohydrological metrics derived from the flow and redistribution of moisture. A simple thermohydrochemical model to investigate a three-process coupling (thermal-hydrological-chemical) was presented. The redistribution of chloride was evaluated because the chemical behavior is well known and defensible. In addition, it is very important to overall system performance. For all of the simulations completed, chloride was found to be extremely concentrated in the fluids that eventually return to the engineered barrier system. Chloride concentration and mass flux were increased from ambient by over a factor of 1000 for some simulations. Thermohydrology was found to have the potential to significantly alter chemistry from ambient conditions.

Esh, David Whittaker

1998-11-01

121

Structural geology report: Spent Fuel Test - Climax Nevada Test Site  

SciTech Connect

We performed underground mapping and core logging in the Climax Stock, a granitic intrusive at the Nevada Test Site, as part of a major field test to determine the feasibility of using granitic or crystalline rock for the underground storage of spent fuel from a nuclear reactor. This mapping and logging identified more than 2500 fractures, over 1500 of which were described in enough detail to allow statistical analyses and orientation studies to be performed. We identified eight joint sets, three major shear sets, and a fault zone within the Spent Fuel Test - Climax (SFT-C) portion of the Stock. Joint sets identified within the SFT-C and elsewhere in the Stock correlated well. The orientations of joint sets identified by other investigators were consistent with our findings, indicating that the joint sets are persistent and have a relatively uniform orientation throughout a major portion of the Stock. The one joint set not seen elsewhere in the Stock is healed and the wall rock is altered, implying that healed joints were not included in the mapping criteria used by other investigators. The shear sets were distinguished from the joint sets by virtue of crushed minerals, continuous clay infilling, and other evidences of shearing, and from faults by the lack of offsetting. Previous investigators working mainly in the Pile Driver Drifts identified two of the shear sets. The third set, being nearly parallel to these Drifts had not been identified previously. The fault zone identified at the far (Receiving Room) end of the project is oriented approximately N45{sup 0}E-75{sup 0}SE, similar to both the Boundary and Shaft Station Faults. We have, therefore, concluded that the Receiving Room Fault is one of a series of normal faults that occur within the Climax Stock and that are possibly related, in both age and genesis, to the Boundary Fault. 52 refs., 26 figs., 11 tabs.

Wilder, D.G.; Yow, J.L. Jr.

1984-10-01

122

Comprehending Geologic Time  

NSDL National Science Digital Library

This online calculator helps students understand the classic analogy of relating the geologic time scale to a yard stick. It will help reinforce the concept of the briefness of human history relative to the age of the Earth.

123

Experiencing Structural Geology  

ERIC Educational Resources Information Center

Describes an undergraduate structural geology course that incorporates field lab time and research. Lectures, outside readings, and in-class experimentation are coordinated with the field work to prepare a scientific report. (MA)

Davis, George H.

1978-01-01

124

Economic Geology (Oil & Gas)  

ERIC Educational Resources Information Center

Briefly reviews the worldwide developments in petroleum geology in 1971, including exploration, new fields, and oil production. This report is condensed from the October Bulletin of the American Association of Petroleum Geologists. (PR)

Geotimes, 1972

1972-01-01

125

Devil's Tower Geology  

NSDL National Science Digital Library

This site from the National Park Service briefly addresses the geology of Devil's Tower. The evolution of various theories on the formation of the tower are discussed. A slide show of the emplacement of the tower is also available.

National Park Service (NPS)

126

Geologic Puzzles: Morrison Formation  

NSDL National Science Digital Library

Images of faulted strata, tilted turbidites, and beach rocks bring the field into the classroom, giving students practice in doing what geoscientists do. These images are examples of geologic puzzles.

Macdonald, Heather

127

Geology and Human Health  

NSDL National Science Digital Library

This site contains a variety of educational and supporting materials for faculty teaching in the emerging field of geology and human health. You will find links to internet resources, books, teaching activities, and a group email list, as well as posters, presentations and discussions from the spring 2004 workshop on Geology and Human Health. These resources reflect the contributions of faculty members from across the country and the collections will continue to grow as materials are developed.

128

Manitoba Geological Survey  

NSDL National Science Digital Library

This site offers materials on Manitoba geology and minerals, mining and mineral exploration, a Digital Elevation Model of Southern Manitoba (DEMSM) landforms including oblique views, an interactive GIS map gallery of minerals and geology, a study of paleofloods in the Red River Basin including photographs illustrating how scientists delineated the paleofloods, and information on the Manitoba Protected Areas Initiative. Some maps and reports are available to download.

129

Johnston Geology Museum  

NSDL National Science Digital Library

The Johnston Geology Museum is part of the Emporia State University Earth Science Department. There is an online virtual tour of the collection which includes a Cretaceous mosasaur, a giant ground sloth, mastodon bones and tusk, brachiopods, Paleozoic corals, sedimentary structures, minerals and crystals. The Museum contains geological specimens predominantly from Kansas, and include the world famous Hamilton Quarry Fossil Assemblage, the Tri-State Mining Display, petrified tree stumps, and the Hawkins and the Calkins Indian Artifact Collections.

2011-07-07

130

Oahu Geology Field Exercises  

NSDL National Science Digital Library

Three field guides are available to sites of geologic interest on Oahu. One is a visit to a landslide occurring in a neighborhood; another focuses on developing observational skills and determining the sequence of geologic events evident in a stratigraphic section; a third examines features associated with formation of a volcanic tuff ring. The worksheets are designed for teachers to implement as-is or modify for their classes.

131

Advances in Planetary Geology  

NASA Technical Reports Server (NTRS)

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.

Grant, John A., III; Nedell, Susan S.

1987-01-01

132

Geologic Time Discussion Analogies  

NSDL National Science Digital Library

The slides provide a fun way of discussing the immensity of geologic time and help to grasp the age of the earth, the time gaps between major geologic events, and the relative minuteness of humans time on earth. After the discussion with the class, students are given opportunity to develop their own analogies using "everyday" things (other than the calendar and money examples used in this activity).

Fay, Noah

133

Three-dimensional geologic map of the Hayward fault, northern California: Correlation of rock unites with variations in seismicity, creep rate, and fault dip  

USGS Publications Warehouse

In order to better understand mechanisms of active faults, we studied relationships between fault behavior and rock units along the Hayward fault using a three-dimensional geologic map. The three-dimensional map-constructed from hypocenters, potential field data, and surface map data-provided a geologic map of each fault surface, showing rock units on either side of the fault truncated by the fault. The two fault-surface maps were superimposed to create a rock-rock juxtaposition map. The three maps were compared with seismicity, including aseismic patches, surface creep, and fault dip along the fault, by using visuallization software to explore three-dimensional relationships. Fault behavior appears to be correlated to the fault-surface maps, but not to the rock-rock juxtaposition map, suggesting that properties of individual wall-rock units, including rock strength, play an important role in fault behavior. Although preliminary, these results suggest that any attempt to understand the detailed distribution of earthquakes or creep along a fault should include consideration of the rock types that abut the fault surface, including the incorporation of observations of physical properties of the rock bodies that intersect the fault at depth. ?? 2005 Geological Society of America.

Graymer, R. W.; Ponce, D. A.; Jachens, R. C.; Simpson, R. W.; Phelps, G. A.; Wentworth, C. M.

2005-01-01

134

Minnesota Geological Survey  

NSDL National Science Digital Library

The Minnesota Geological Survey (MGS) was established in 1872 as part of the University of Minnesota. The function of the MGS is to serve "the people of Minnesota by providing systematic geoscience information to support stewardship of water, land, and mineral resources." This website from the Digital Conservancy at the University of Minnesota provides access to all of items published by the MGS. The items are contained within the Collections area, and visitors will find headings here such as "Geology of Minnesota Parks," "County Atlas Series," and the "Bulletin of the Minnesota Geological and Natural History Survey." First-time visitors can check out the Recent Submissions area on the right-hand side of the page to look over some new findings, including hydrogeological maps of different counties around the state. One item that should not be missed is the "Geology of Minnesota: A Centennial Volume" from 1972. It's a tremendous volume and one that cannot be ignored by students of the physical landscape and geological history of the state.

2012-09-21

135

77 FR 6580 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...  

Federal Register 2010, 2011, 2012, 2013

...Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological...the purposes of the National Geological Mapping Act of 1992; the Federal, State, and...of the National Cooperative Geological Mapping Program and National Geological and...

2012-02-08

136

Project Primary Geology  

NSDL National Science Digital Library

Project Primary is a collaboration of professors from the departments of Botany-Microbiology, Chemistry, Education, Geology, Physics, and Zoology at Ohio Wesleyan University and K-3 teachers from Ohio's Delaware, Marion, and Union Counties to produce hands-on activities for the teaching of science. The geology activities are appropriate for children in grades K-12. Collectively, the goals for these activities are to demonstrate the inter-relatedness of life and the physical planet, the importance of understanding scientific phenomena for all people, not just future scientists, to impart knowledge which leads through student curiosity to continued inquiry, and to spur creativity. Topics covered include earthquakes, behavior of Earth materials, plate tectonics, the surface of the Earth, volcanoes, and geologic time and the evolution of the Earth.

Fryer, Karen

137

Helium studies in geology  

NASA Astrophysics Data System (ADS)

A special issue of the Journal of Geophysical Research—Solid Earth and Planets will be devoted to the topic "Helium Studies in Geology." Both helium isotopic research and helium 4 investigations on any phase of geologic application will be included. Individuals are welcome to submit manuscripts for this special issue. The deadline for receipt of papers through the normal JGR submission process is May 30, 1986. Please indicate that the manuscript is for the special issue. For additional information, contact G. M. Reimer, U.S. Geological Survey, MS 963, Denver Federal Center, Denver, CO 80225; telephone: 303236-7886 or JGR editor Gerald Schubert, Department of Earth and Space Sciences, University of California, Los Angeles, CA 90024; telephone: 213-82 5-4577.

138

SOPAC marine geology atlases  

SciTech Connect

The US Geological Survey conducted a series of marine geologic and geophysical cruises in the southwest Pacific Ocean in 1982 and 1984 as part of a program with participation by Australia and New Zealand. These two SOPAC expeditions obtained various data, which have been compiled into a series of charts and thematic products for the offshore areas of Tonga, Fiji, Vanuatu, the Solomon Islands, and Papua New Guinea. The maps and charts presently being compiled or revised combine previously collected data with information from the SOPAC expeditions. Regional charts at a scale of approximately 1:3 million are included, and more detailed coverage is available at 1:1 million. Additional geologic information-such as gravity, magnetics, and possibly sediment isopachs-is provided on overlays to the topographic base charts. Reproductions of the seismic reflection data are also included, and tracklines with both time marks and shotpoints will permit correlation with the analog and digital seismic records.

Chase, T.E.; Seekins, B.A.; Young, J.D.; Wahler, J.A.

1986-07-01

139

Geological fakes and frauds  

NASA Astrophysics Data System (ADS)

Some geological fakes and frauds are carried out solely for financial gain (mining fraud), whereas others maybe have increasing aesthetic appeal (faked fossils) or academic advancement (fabricated data) as their motive. All types of geological fake or fraud can be ingenious and sophisticated, as demonstrated in this article. Fake gems, faked fossils and mining fraud are common examples where monetary profit is to blame: nonetheless these may impact both scientific theory and the reputation of geologists and Earth scientists. The substitution or fabrication of both physical and intellectual data also occurs for no direct financial gain, such as career advancement or establishment of belief (e.g. evolution vs. creationism). Knowledge of such fakes and frauds may assist in spotting undetected geological crimes: application of geoforensic techniques helps the scientific community to detect such activity, which ultimately undermines scientific integrity.

Ruffell, Alastair; Majury, Niall; Brooks, William E.

2012-02-01

140

Geologic map of Mars  

USGS Publications Warehouse

This global geologic map of Mars, which records the distribution of geologic units and landforms on the planet's surface through time, is based on unprecedented variety, quality, and quantity of remotely sensed data acquired since the Viking Orbiters. These data have provided morphologic, topographic, spectral, thermophysical, radar sounding, and other observations for integration, analysis, and interpretation in support of geologic mapping. In particular, the precise topographic mapping now available has enabled consistent morphologic portrayal of the surface for global mapping (whereas previously used visual-range image bases were less effective, because they combined morphologic and albedo information and, locally, atmospheric haze). Also, thermal infrared image bases used for this map tended to be less affected by atmospheric haze and thus are reliable for analysis of surface morphology and texture at even higher resolution than the topographic products.

Tanaka, Kenneth L.; Skinner, James A., Jr.; Dohm, James M.; Irwin, Rossman P., III; Kolb, Eric J.; Fortezzo, Corey M.; Platz, Thomas; Michael, Gregory G.; Hare, Trent M.

2014-01-01

141

Global sedimentary geology program  

SciTech Connect

The Society of Economic Paleontologists and Mineralogists, in collaboration with the International Association of Sedimentologists and the International Union of Geological Sciences Committee on Sedimentology, is developing a new international study under the provisional title of Global Sedimentary Geology Program (GSGP). Initially, three research themes are being considered: (1) event stratigraphy-the documentation of examples of mass extinctions, eustatic fluctuations in sea level, major episodes of volcanisms, and changes in ocean composition; (2) facies models in time and space-an expansion of the existing data base of examples of facies models (e.G., deltas, fluvial deposits, and submarine fans) and global-scale study of the persistence of facies at various times in geologic history; and (3) sedimentary indices of paleogeography and tectonics-the use of depositional facies and faunas in paleogeography and in assessing the timing, locus, and characteristics of tectonism. Plans are being developed to organize pilot projects in each of these themes.

Ginsburg, R.N.; Clifton, H.E.; Weimer, R.J.

1986-07-01

142

Sedimentology and petroleum geology  

SciTech Connect

In this introduction to sedimentology and petroleum geology the subjects, which are closely related but mostly treated separately, are integrated. The first part covers the basic aspects of sedimentology, sedimentary geochemistry and diagenesis, including brief discussions of flow in rivers and channels, types of sediment transport, lake and river deposits, deltas (river-dominated, tide-dominated, and wave-dominated) and the water budget. Principles of stratigraphy, seismic stratigraphy and basin modeling form the basis for the last part on petroleum geology. Here subjects include the composition of kerogen and hydrocarbons, theories of migration and trapping of hydrocarbons and properties of reservoir rocks. Finally, short introductions to well logging and production geology are given.

Bjorlykke, K.

1989-01-01

143

Geology By Lightplane  

NSDL National Science Digital Library

In 1966, Professor Louis J. Maher of the University of Wisconsin-Madison's Department of Geology and Geophysics piloted a department-owned Cessna over the continental US taking photos for use in his geology courses. As Maher flew, his trusty co-pilot and graduate assistant, Charles Mansfield, snapped the photos. The resulting collection is an assortment of breathtaking images of classic geological features, now available online for noncommercial use by educators (download via FTP). Maher gives us birds-eye views of structural features in Wyoming's Wind River Range, sedimentary strata in Arches National Park and the Grand Canyon, glacial landscapes in Northern Minnesota, and ancient lava flows in Arizona, to name just a few.

Maher, Louis J.

2001-01-01

144

Roping Geologic Time  

NSDL National Science Digital Library

After having talked about the geologic time scale (Precambrian: prior to 570 Ma; Paleozoic: 570-245 Ma; Mesozoic: 245-65 Ma; Cenozoic: 65 Ma - Present), I ask for two volunteers from the class to hold a rope that is 50 feet long. I say that one end is the beginning of the Earth (4.6 billion years ago), and the other is today. I then give out 16 clothes pins and ask various students to put a cloths pin on the 'time line' at various 'geologic events'. For example, I ask them to put one where the dinosaurs died out (end of the Mesozoic). They almost invariably put it much too old (65 Ma is less than 2% of Earth history!). Then I ask them to put one on their birthday (they now laugh). Then I ask them to put one where we think hominoids (humans) evolved (~3-4 Ma), and they realize that we have not been here very long geologically. Then I ask them to put one at the end of the Precambrian, where life took off in terms of the numbers of species, etc. They are amazed that this only represents less than 15% of Earth history. Throughout the activity I have a quiz going on where the students calculate percentages of Earth History for major geologic events, and compare it to their own ages. On their time scale, the dinosaurs died only about two 'months' ago! The exercise is very effective at letting them get a sense of how long geologic time is, and how 'recently' some major geologic events happened when you consider a time scale that is the age of the earth.

Richardson, Randall

145

Mineral formation and redox-sensitive trace elements in a near-surface hydrothermal alteration system  

SciTech Connect

A recent hydrothermal mudpool at the southwestern slope of the Rincon de la Vieja volcano in Northwest Costa Rica exhibits an argillic alteration system formed by intense interaction of sulfuric acidic fluids with wall rock materials. Detailed mineralogical analysis revealed an assemblage with kaolinite, alunite, and opal-C as the major mineral phases. Electron paramagnetic resonance spectroscopy (EPR) showed 3 different redox-sensitive cations associated with the mineral phases, Cu{sup +} is structure-bound in opal-C, whereas VO{sup 2+} and Fe{sup 3+} are located in the kaolinite structure. The location of the redox-sensitive cations in different minerals of the assemblage is indicative of different chemical conditions. The formation of the alteration products can be described schematically as a 2-step process. In a first step alunite and opal-C were precipitated in a fluid with slightly reducing conditions and a low chloride availability. The second step is characterized by a decrease in K{sup +} activity and subsequent formation of kaolinite under weakly oxidizing to oxidizing redox conditions as indicated by structure-bound VO{sup 2+} and Fe{sup 3+}. The detection of paramagnetic trace elements structure-bound in mineral phases by EPR provide direct information about the prevailing redox conditions during alteration and can, therefore, be used as additional insight into the genesis of the hydrothermal, near-surface system.

Gehring, A.U. [ETH Zurich, Schlieren (Switzerland). Inst. for Terrestrial Ecology] [ETH Zurich, Schlieren (Switzerland). Inst. for Terrestrial Ecology; [ETH Zentrum, Zurich (Switzerland). Office of Planning; Schosseler, P.M.; Weidler, P.G. [ETH Zurich (Switzerland). Inst. for Physical Chemistry] [ETH Zurich (Switzerland). Inst. for Physical Chemistry

1999-07-01

146

BGS Geological Timechart  

NSDL National Science Digital Library

This is the geological time scale developed by the British Geological Survey. The principal chart is the Phanerozoic (Cambrian to Quaternary) timescale. The names of the individual periods are live links, each one leading to a chart showing the subdivisions of each period into epochs and ages. The Proterozoic and Neoproterozoic sections are also linked to further subdivisions into eras and periods. Dates are in millions of years before present. A guide on the front page describes the bases for the divisions used on this time scale and how to use it, and a downloadable version is also provided.

147

Understanding Geological Time  

NSDL National Science Digital Library

In this classroom activity, middle school students gain an understanding of geologic time. The activity opens with background information for teachers about carbon and radiometric dating. In a classroom discussion, students share what they know about geologic time. Then, working in small groups responsible for different eras, students create a timeline for their assigned era by conducting library and Internet research. The activity concludes by having students review all the timelines to compare how long humans have been on the Earth to the length of time dinosaurs inhabited the planet.

148

Petroleum development geology  

SciTech Connect

An overview of geological concepts and reservoir engineering practices as they apply to the field of development (production) geology is presented. The author touches on nearly every aspect of the field in the 21 chapters of the book. He summarizes the basic depositional origin, sedimentary characteristics, and petrology of hydrocarbon-bearing rocks. He discusses physical properties, origin, and migration of subsurface oil and gas, oil field water, and their behavior, including subsurface pressures and fluid mechanics. Also covered are various methods of estimating reserves, the major tools of the trade and their limitations, and case histories.

Dickey, P.A.

1986-01-01

149

Project Earth Science: Geology  

NSDL National Science Digital Library

Now you can literally explain what it's like "between a rock and a hard place!" Use Project Earth Science: Geology to introduce your students to plate tectonics and teach them what causes volcanoes and earthquakes. Lead explorations of these and other larger-than-the-classroom geological phenomena with the teacher-tested, Standards -based activities. Earth's physical evolution and dynamic processes are carefully explained in language accessible to students and teachers. Supplemental readings provide educators with the background information to answer student questions and concerns.

Ford, Brent A.

2001-01-01

150

Geological processes and evolution  

USGS Publications Warehouse

Geological mapping and establishment of stratigraphic relationships provides an overview of geological processes operating on Mars and how they have varied in time and space. Impact craters and basins shaped the crust in earliest history and as their importance declined, evidence of extensive regional volcanism emerged during the Late Noachian. Regional volcanism characterized the Early Hesperian and subsequent to that time, volcanism was largely centered at Tharsis and Elysium, continuing until the recent geological past. The Tharsis region appears to have been largely constructed by the Late Noachian, and represents a series of tectonic and volcanic centers. Globally distributed structural features representing contraction characterize the middle Hesperian. Water-related processes involve the formation of valley networks in the Late Noachian and into the Hesperian, an ice sheet at the south pole in the middle Hesperian, and outflow channels and possible standing bodies of water in the northern lowlands in the Late Hesperian and into the Amazonian. A significant part of the present water budget occurs in the present geologically young polar layered terrains. In order to establish more firmly rates of processes, we stress the need to improve the calibration of the absolute timescale, which today is based on crater count systems with substantial uncertainties, along with a sampling of rocks of unknown provenance. Sample return from carefully chosen stratigraphic units could calibrate the existing timescale and vastly improve our knowledge of Martian evolution.

Head, J. W.; Greeley, R.; Golombek, M. P.; Hartmann, W. K.; Hauber, E.; Jaumann, R.; Masson, P.; Neukum, G.; Nyquist, L. E.; Carr, M. H.

2001-01-01

151

Ontology for Structural Geology  

NASA Astrophysics Data System (ADS)

We present our comprehensive process-based ontology for Structural Geology. This ontology covers major domain concepts, especially those related to geological structure type, properties of these structures, their deformation mechanisms, and the factors that control which deformation mechanisms may operate under certain conditions. The structure class in our ontology extends the planetary structure class of the SWEET ontology by providing additional information required for use in the structural geology domain. The classification followed the architectures of structures, such as structure element, set, zone, and pattern. Our deformation mechanism class does not have a corresponding class in SWEET. In our ontology, it has two subclasses, Macro- and Micro- mechanisms. The property class and the factor class are both subclasses of the physical property class of SWEET. Relationships among those concepts are also included in our ontology. For example, the class structure element has properties associated with the deformation mechanisms, descriptive properties such as geometry and morphology, and physical properties of rocks such as strength, compressibility, seismic velocity, porosity, and permeability. The subject matter expertise was provided by domain experts. Additionally, we surveyed text books and journal articles with the goal of evaluating the completeness and correctness of the domain terms and we used logical reasoners and validators to eliminate logical problems. We propose that our ontology provides a reusable extension to the SWEET ontology that may be of value to scientists and lay people interested in structural geology issues. We have also implemented prototype services that utilize this ontology for search.

Zhong, J.; McGuinness, D. L.; Antonellini, M.; Aydin, A.

2005-12-01

152

IDAHO FLUVIAL GEOLOGY  

EPA Science Inventory

Restricted availability. Major Attributes: Polygons described by geologic type codes & descriptions. May be incorporated into maps at the state/county/basin scale. Probably too coarse for use at the site scale. Scale: 1:500:000. Extent: Idaho. Projection: Albers. Source: ...

153

Briefing on geological sequestration  

EPA Science Inventory

Geological sequestration (GS) is generally recognized as the injection and long-term (e.g., hundreds to thousands of years) trapping of gaseous, liquid or supercritical carbon dioxide (CO2) in subsurface media ? primarily saline formations, depleted or nearly depleted oil and gas...

154

Marine Environmental Geology  

NSDL National Science Digital Library

This course is an introduction to the aspects of marine geology and oceanography that affect the environment and marine resources. Service-learning is an essential component of how students learn about the earth. We deliver part of the content of this course by arranging for students to solve a problem with a local community partner.

Course taught by Prof. Ed Laine, Bowdoin College (edlaine@bowdoin.edu) and Cathryn Field, Lab Instructor (cfield@bowdoin.edu). Example compiled by Suzanne Savanick, Science Education Resource Center (ssavanic@carleton.edu).

155

Public perceptions of geology  

NASA Astrophysics Data System (ADS)

Geological issues are increasingly intruding on the everyday lives of ordinary people. Whether it be onshore exploration and extraction of oil and gas, deep injection of water for geothermal power or underground storage of carbon dioxide and radioactive waste, many communities across Europe are being faced with potentially contested geological activity under their backyard. As well as being able to communicate the technical aspects of such work, geoscience professionals also need to appreciate that for most people the subsurface is an unfamiliar realm. In order to engage communities and individuals in effective dialogue about geological activities, an appreciation of what 'the public' already know and what they want to know is needed, but this is a subject that is in its infancy. In an attempt to provide insight into these key issues, this study examines the concerns the public have, relating to geology, by constructing 'Mental Models' of people's perceptions of the subsurface. General recommendations for public engagement strategies will be presented based on the results of selected case studies; specifically expert and non-expert mental models for communities in the south-west of England.

Gibson, Hazel; Stewart, Iain; Anderson, Mark; Pahl, Sabine; Stokes, Alison

2014-05-01

156

Physical Geology Lecture Online  

NSDL National Science Digital Library

Maintained by Dr. Pamela J. W. Gore of Georgia Perimeter College, the Physical Geology Lecture Online is a complete online interactive course. Through descriptions, photographs, and illustrations, students can learn the basics of minerals, rocks, volcanoes, soils, earthquakes, erosion, mass wasting, and more. Although the site was created for a specific college course, any student can browse and learn about the many topics covered.

Gore, Pamela J.

1994-01-01

157

Layer Cake Geology  

NSDL National Science Digital Library

This activity provides young students with a relevant model (a layer cake) to help them understand concepts about sedimentary rock layers (such as the Law of Superposition), correlation of the rock record with geologic time and relative ages of rocks and fossils.

Ward, Molly

158

Geology: The Active Earth.  

ERIC Educational Resources Information Center

Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Geology: The Active Earth." Contents are organized into the following…

Braus, Judy, Ed.

1987-01-01

159

The geology of Venus  

NASA Astrophysics Data System (ADS)

This paper summarizes the emerging picture of the surface of Venus provided by high-resolution earth-based radar telescopes and orbital radar altimetry and imaging systems. The nature and significance of the geological processes operating there are considered. The types of information needed to complete the picture are addressed.

Basilevsky, A. T.; Head, J. W.

160

Characterizing Lunar Crustal Geology  

NASA Astrophysics Data System (ADS)

In our initiative to return to the Moon, knowledge of regional crustal geology is necessary both for locating resources of scientific interest and for establishing a sustained human presence. Characterizing crustal geology with global remote sensing data is difficult due to the types of weathering processes experienced by an airless, geologically torpid planetary body, which tend to reduce lithologic contrast and obscure the lithology of true bedrock. Fortunately, these processes are relatively straightforward, involving parameters with largely understood, fixed rates of flux. We describe a methodology for characterizing the chemical and mineralogical compositions of discrete geologic units, interpreted from remotely sensed surface spectra. The method utilizes two established techniques: small impact ejecta viewing and extrapolation (SIEVE) (McCord et al., JGR 1981; Staid & Pieters, LPSC 29; Kramer et al., LPSC 36; Kramer et al., JGR (in review)) and spectral mixing analysis (SMA) (Adams & Gillespie, Cambridge Univ. Press 2006, and references therein). The results of this work will be invaluable for identifying regions of interest for current and future lunar missions, such as Chandrayaan-1, carrying NASA's Moon Mineralogy Mapper, and Lunar Reconnaissance Orbiter. Furthermore, the methodology can be used to explore other planetary bodies that experience similar weathering processes (e.g., Mercury, Ceres, Vesta, and Mars).

Kramer, G.; Combe, J.; McCord, T.

2007-12-01

161

Digital solar system geology  

NASA Technical Reports Server (NTRS)

All available synoptic maps of the solid-surface bodies of the Solar System were digitized for presentation in the planned Atlas of the Solar System by Greeley and Batson. Since the last report (Batson et al., 1990), preliminary Uranian satellite maps were replaced with improved versions, Galilean satellite geology was simplified and digitized, structure was added to many maps, and the maps were converted to a standard format, with corresponding standing colors for the mapped units. Following these changes, the maps were re-reviewed by their authors and are now undergoing final editing before preparation for publication. In some cases (for Mercury, Venus, and Mars), more detailed maps were digitized and then simplified for the Atlas. Other detailed maps are planned to be digitized in the coming year for the Moon and the Galilean satellites. For most of the remaining bodies such as the Uranian satellites, the current digitized versions contain virtually all the detail that can be mapped given the available data; those versions will be unchanged for the Atlas. These digital geologic maps are archived at the digital scale of 1/16 degree/ pixel, in sinusoidal format. The availability of geology of the Solar System in a digital database will facilitate comparisons and integration with other data: digitized lunar geologic maps have already been used in a comparison with Galileo SSI observations of the Moon.

Batson, R. M.; Kozak, R. C.; Isbell, Nancy K.

1991-01-01

162

Geology of Mars  

NSDL National Science Digital Library

This website provides information about the six geological processes that are either currently operating on Mars or have operated during Martian history. These include the aeolian, cratering, hydro, landslides, tectonic, and volcanic processes. Example images of the results of these processes are provided.

Hsui, Albert T.

2004-07-14

163

Petroleum development geology  

Microsoft Academic Search

This book describes most of the principles and methods of petroleum geology. The tools of the petroleum geologist are discussed, including study of samples, mud logs, cores, and wire-line logs. The different types of sand bodies are described, with directions for distinguishing those deposited as beaches, river channels, and in other depositional environments, using wire-line logs and cores. Carbonate reservoirs

Dickey

1979-01-01

164

Radiometric dating in geology  

NASA Astrophysics Data System (ADS)

The method of dating rocks and minerals is known as geochronology. Although in principle this term could be applied to estimation of relative ages according to traditional geological observation, it is nowadays usually restricted to the quantitative measurement of geological time using the constant-rate natural process of radioactive decay. 14C dating is a technique based on measuring the residual radioactivity of this isotope which decays exponentially from the time of death of organisms which extract it from the atmosphere (e.g. when a living tree becomes simply 'wood'). The halflife of this decay is only 5600 years. Even using pre-concentration techniques and highly sensitive detectors, the practical range of the dating method does not extend back beyond about 100000 years-a period utterly insignificant in terms of the geological evolution of the Earth, which extends over the past 4500 million years. For geological dating one requires naturally occurring elements with much longer halflives. Most of the handful of appropriate decay schemes are listed. Most of the parent elements are rare metal constituents in the bulk chemical composition of the Earth. For such 'trace' elements it is generally convenient to express their concentration in natural materials in parts per million by weight (ppm) and even in the one case of a fairly common element (potassium) only a very small proportion occurs as the radioactive 40K. Also, some of the halflives are very long, even by geological reckoning, so that the actual level of natural radioactivity is rarely more than a few disintegrations per minute per gram.

Pankhurst, R. J.

1980-11-01

165

Computer Simulation of Geologic Systems.  

National Technical Information Service (NTIS)

The Geologic Simulation Model (GSM) developed under the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) project at the Pacific Northwest Laboratory for the Department of Energy is a quasi-deterministic process-response model which simula...

M. G. Foley

1982-01-01

166

Geology of California. Second Edition  

SciTech Connect

Two introductory chapters familiarize readers with basic geologic concepts. The following chapters describe the geology of each of California's 11 geomorphic provinces; the San Andreas fault and offshore geology are discussed in two separate chapters. Four appendices acquaint readers with technical words and terms, common minerals and rocks in California, geologic time, and geologic theories that pertain to California. During the 1960s evidence collected from the east Pacific sea floor off the western coast of North America gave scientists supporting data for Alfred Wegener's 1910 theory of continental drift. In addition to the confirmation of continental drift, since the 1960s scientists have discovered paleomagnetism, sea-floor spreading, exotic and suspect terranes, and polar wandering. These important concepts have had far reaching effects about how we understand the geology of California and how this region has evolved through geologic time. Improved investigative procedures enable earth scientists to comprehend previously puzzling aspects of California's geology.

Norris, R.M.; Webb, R.W.

1990-01-01

167

Geology and Radiometry of Chalkidiki.  

National Technical Information Service (NTIS)

A brief geological description of Chalkidiki (Greece) is given followed by car-borne-scintillometer (CBS) survey results showing that granitic rocks in Central and Eastern Chalkidiki constitute the most promising geological formations for uranium minerali...

D. G. Minatidis

1980-01-01

168

Geological Investigation of Uranium Resources.  

National Technical Information Service (NTIS)

A geologic investigation of the Ogcheon uraniferous black shale has been carried out at the northeast of Miweon. Geology of the study area consists of following stratigraphic sequences in ascending order pebbly phyllitic rock formation, lower black slate ...

1983-01-01

169

Using Snow to Teach Geology.  

ERIC Educational Resources Information Center

A lesson plan, directed at middle school students and older, describes using snow to study the geological processes of solidification of molten material, sedimentation, and metamorphosis. Provides background information on these geological processes. (MCO)

Roth, Charles

1991-01-01

170

Towards understanding how surface life can affect interior geological processes: a non-equilibrium thermodynamics approach  

Microsoft Academic Search

Life has significantly altered the Earth's atmosphere, oceans and crust. To what extent has it also affected interior geological processes? To address this question, three models of geological processes are formulated: mantle convection, continental crust uplift and erosion and oceanic crust recycling. These processes are characterised as non-equilibrium thermodynamic systems. Their states of disequilibrium are maintained by the power generated

J. G. Dyke; F. Gans; A. Kleidon

2011-01-01

171

USGS National Geologic Map Database: State-wide Geologic Maps  

NSDL National Science Digital Library

This search tool provides descriptions and availability information for geologic maps of the 50 States, the District of Columbia, and Puerto Rico. These geologic maps are published by a variety of organizations, including State geologic agencies, the U.S. Geological Survey (USGS), universities, and private companies. Title, date, scale, publisher, series (where applicable), and basic ordering information is provided for each map. A place name search and an advanced search using geologic themes, areas, publishers and other criteria allow for more specific queries to the database.

172

Ordering Geologic Events and Interpreting Geologic History: The Grand Canyon  

NSDL National Science Digital Library

This activity is designed to help students recognize the connections among things like rock identification and map reading with the "story" that these things can tell us in terms of geologic history. Students have already learned about using observation to identify rocks and the principles of interpreting geologic cross-sections. The activity gives students practice in rock ID, topo map reading, geologic map reading and the aspects of geologic time. Students work with rock samples and a geologic map of the Grand Canyon to interpret a history for the area.

Wenner, Jennifer

173

Geologic Map of New Jersey  

NSDL National Science Digital Library

This map displays the sedimentary rocks of the Cenozoic, Mesozoic, and Paleozoic eras as well as the igneous and metamorphic rocks of the Mesozoic and Precambrian eras. There is a pagesize copy of the geologic map, a brief description of the geology and physiographic provinces of New Jersey, and information on bedrock geologic maps of New Jersey (in CD-ROM format).

174

The Second Flowering of Geology.  

ERIC Educational Resources Information Center

Discusses two "golden" ages in geological investigations/inquiry. The first, extending from the late eighteenth century through the early nineteenth century, established geology as a science based on naturalistic principles. The second, beginning after World War II, is characterized by advances in geological specialities and explanations based on…

Cloud, Preston

1983-01-01

175

Geology Training Module  

NSDL National Science Digital Library

This is a lesson where learners review the basic requirements for human survival. Learners will use an online, multimedia module, to which they make changes to Earth's layers and draw conclusions about the geologic conditions that are necessary for human survival. The lesson models scientific inquiry using the 5E instructional model and includes teacher notes, prerequisite concepts, common misconceptions, student journal and reading. This is lesson one in the Astro-Venture Geology Training Unit that were developed to increase students' awareness of and interest in astrobiology and the many career opportunities that utilize science, math and technology skills. The lessons are designed for educators to use with the Astro-Venture multimedia modules.

176

Geology of the Caribbean  

USGS Publications Warehouse

The Venezuelan and Colombian basins are located on the Caribbean Plate whilst the Yucatan basin is on the North American Plate. The processes occurring at the boundaries between the Caribbean Plate and the adjacent North American, South American and Cocos Plates, and the resulting surface features and patterns of volcanic and earthquake activity are described. Most of the Caribbean area is floored by atypical oceanic crust and its most valuable main geologic resources identified so far are petroleum, together with sand and gravel. Geological research is being carried out with techniques for broad-range swath imaging of the seafloor, such as GLORIA, and for directly measuring the movement between plates. -J.G.Harvey

Dillon, W. P.; Edgar, N. T.; Scanlon, K. M.; Klitgord, K. D.

1987-01-01

177

Geology of Britain Viewer  

NSDL National Science Digital Library

If you've ever wanted to wander from John O'Groats to the Cotswolds without leaving your desk, this most wonderful website is for you. Created by the British Geological Survey, the Geology of Britain viewer helps interested parties learn more about the landforms in their backyards. After opening the viewer, visitors can click on an area of interest to look at everything from possible earthquake threats to rock layers to soil composition and more. Visitors should note that they can zoom in on the map and also use place names to refine their searches via the Go to Location button. Additionally, the basemap can be modified to show satellite photographs or various street maps as overlays. Finally, the site contains walking guides for several regions of Britain that might be helpful for those with a penchant for perambulation.

178

Elements of petroleum geology  

SciTech Connect

This work surveys the modern science of petroleum geology. Its aim is twofold: to describe generation, migration, and entrapment of oil and gas, and to outline the various procedures used in their location, evaluation, and production. Selley begins the book with an account of the physical and chemical properties of petroleum, followed by a review of the methods of petroleum exploration and production, including drilling, geophysical exploration techniques, wireline logging, and subsurface geological mapping. Selley next describes the temperatures and pressures of the subsurface environment and the composition and hydrodynamics of connate fluids. He goes on to examine the generation and migration of petroleum, reservoir rocks, and trapping mechanisms, the habitat of petroleum in sedimentary basins, and the composition and formation of tar sands and oil shales. Selley ends the book with a brief review of prospect risk analysis, reserve estimation, and other economic topics.

Selley, R.C.

1985-01-01

179

Fundamentals of Structural Geology  

NSDL National Science Digital Library

Fundamentals of Structural Geology is a textbook that emphasizes modern techniques of field data acquisition and analysis, the principles of continuum mechanics, and the mathematical and computational skills necessary to quantitatively describe, model, and explain the deformation of rock in Earth's lithosphere. This site provides an online interface for the book with supplementary materials for readers, instructors, and students. Resources include color photographs of outcrops, textbook figures, and supplementary illustrations for classroom presentations; student exercises to develop Matlab skills; Matlab scripts to make textbook figures dynamic, introduction to the concepts of differential geometry, mechanical models, and the evolution of geologic structures; and research quality data sets and solutions for instructors. The site also includes book information and links to additional resources.

Pollard, David; Fletcher, Raymond; University, Stanford

180

Algebra, Geology and Economics  

NSDL National Science Digital Library

The American Mathematical Association of Two-Year Colleges (AMATYC) has compiled a collection of mathematics resources related to various subjects and disciplines. âÂÂMath Across the Community College Curriculumâ is the title of the collection, which includes great math resources and applications for educators and students alike. In this particular resource, concepts from algebra, geology and economics are intertwined to create two dynamic activities for students. The projects, created by Mary Dowse, Tom Gruszka, and George Muncrief of Western New Mexico University, include both general learning objectives and subject specific objectives for what students will learn through the completion of the activities. The first activity focuses on the mathematics of economics, and the second activity focuses on geology and graphing. These activities can be easily adapted for use in the classroom, and are also useful for students who are looking for extra practice with these concepts.

Dowse, Mary; Gruszka, Tom; Muncrief, George

2008-04-22

181

Principles of nuclear geology  

SciTech Connect

This book treats the basic principles of nuclear physics and the mineralogy, geochemistry, distribution and ore deposits of uranium and thorium. The application of nuclear methodology in radiogenic heat and thermal regime of the earth, radiometric prospecting, isotopic age dating, stable isotopes and cosmic-ray produced isotopes is covered. Geological processes, such as metamorphic chronology, petrogenesis, groundwater movement, and sedimentation rate are focussed on.

Aswathanarayana, U.

1985-01-01

182

Coastal Geological Processes  

NSDL National Science Digital Library

Coastlines are places of continuous, often dramatic geological activity. They change daily and seasonally, but especially over long time periods. This interactive feature discusses the forces that help shape coastal landforms like cliffs and beaches. Topics include waves, tides, and currents; weathering, erosion, and deposition; and other factors, such as the activity of organisms and human modifications. A background essay and discussion questions are included.

2011-02-03

183

Medical Geology in Africa  

Microsoft Academic Search

\\u000a A large body of evidence points to significant health effects resulting from our interactions with the physical environment\\u000a and we continue to recognise connections between geological materials and processes and human and animal disease. In Africa,\\u000a these relationships have been observed for many years, but only recently have any real attempts been made to formalise their\\u000a study. Africa is a

T. C. Davies

184

Geology: Plate Tectonics  

NSDL National Science Digital Library

This site is the Plate Tectonics portion of the Geology site from the University of California, Berkeley, Museum of Paleontology. This exhibit has a section devoted to the explanation of the history of plate tectonics and a section that focuses on the mechanisms driving plate tectonics. The mechanisms section discusses convection, mid-oceanic ridges, geomagnetic anomalies, deep sea trenches, and island arcs. The site also contains links to numerous animations illustrating historical plate positions and movements.

185

Greater Yellowstone Geology  

NSDL National Science Digital Library

This site features a collection of papers and maps about the Yellowstone hotspot by Dr. Ken Pierce of the Northern Rocky Mountain Science Center, an expert in the field. Papers on this site address topics such as Yellowstone glaciation, tracking the hotspot, the Yellowstone plume head, and a seven-day field trip guide to the quaternary geology and ecology of the Greater Yellowstone Ecosystem. Each downloadable paper map is listed with a brief description and a full citation.

Institute, Mountain P.; Infrastructure, National B.

186

Coastal Geological Processes  

NSDL National Science Digital Library

Coastlines are places of continuous, often dramatic geological activity. They change daily and seasonally, but especially over long time periods. This interactive feature discusses the forces that help shape coastal landforms like cliffs and beaches. Topics include waves, tides, and currents; weathering, erosion, and deposition; and other factors, such as the activity of organisms and human modifications. A background essay and discussion questions are included.

187

Geologic Maps and Geologic Structures: A Texas Example  

NSDL National Science Digital Library

This Historical Geology lab exercise is an accompaniment to lab class instruction about geologic structures (folding and faulting) and geologic maps. It also serves as an excellent introduction to the Geology of the state of Texas. "Coloring" geologic maps, an important part of the exercise, may seem like a very elementary learning technique. But this lab engages students actively, and since the subject is often already somewhat familiar to them, emphasizing both the geology and geography of Texas, students receive it enthusiastically. This activity could be adapted to other regions, since most states have color 8 1/2 by 11 geologic maps available. A color map could be scanned and modified in Photoshop to create a simplified black and white version as was done in the assignment handout.

Steinberg, Roger

188

Geologic Photo Field Trips to View Rocks, Geologic Structures, and Landforms in Introductory Physical Geology  

NSDL National Science Digital Library

Field photographs are used to enhance the instruction in teaching rocks, geologic structures, and landforms in Introductory Physical Geology lecture at East Carolina University. The field photographs are used to enhance the visual component of Physical Geology and are focused on rock outcrops (igneous, sedimentary, and metamorphic), geologic structures (faults and folds), and landforms (volcanic, weathering-erosion, mass wasting, fluvial, wind-desert, coastal, and karst).

Harper, Stephen B.

189

77 FR 38318 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...  

Federal Register 2010, 2011, 2012, 2013

...Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological...planning and implementation of the geologic mapping and data preservation programs. The Committee...the purposes of the National Geological Mapping Act of 1992; the Federal, State,...

2012-06-27

190

76 FR 19783 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...  

Federal Register 2010, 2011, 2012, 2013

...Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological...planning and implementation of the geologic mapping and data preservation programs. The Committee...the purposes of the National Geological Mapping Act of 1992; the Federal, State,...

2011-04-08

191

Geological Survey of Tanzania  

NSDL National Science Digital Library

The United Republic of Tanzania was formed in 1964 by the merger of Tanganyika and Zanzibar and is located on the eastern coast of Africa between the Great Lakes of the Rift Valley. Tanzania has a diverse mineral resource base that includes gold and base metals, diamond-bearing kimberlites, nickel, cobalt, copper, coal resources, and a variety of industrial minerals and rocks such as kaolin, graphite, and dimension stone. This web site was created by the Mineral Resources Department (MRD), a subsidiary of the Ministry of Energy and Minerals, and contains basic information about the country's logistical environment, mineral sector policy, geological database, and more.

1997-01-01

192

geology.com  

NSDL National Science Digital Library

This clearinghouse features an extensive selection of maps, imagery, news articles, and other Earth science resources. Highlights include an interactive map of meteor impact structures, an interactive map showing the highest points in the 50 states, and a state-by-state directory of imagery, maps, and links to geological information. There are also listings for imagery for U.S. cities and the continents, a map of the most dangerous volcanoes in the U.S., a mineral identification chart, and information on stream discharge monitoring.

2006-01-01

193

Geology in North Dakota  

NSDL National Science Digital Library

The Department of Geosciences at North Dakota State University educates visitors about the geologic features and landforms of North Dakota through clear text and astonishing images at this website. In the Glacial Features of North Dakota link, visitors can learn about end moraines, eskers, kettle lakes, and kames. Educators can find amazing photographs of mass wasting including creep, slope failure, and slumps. Users can also find materials on stream features and satellite imagery of North Dakota. While the website concentrates on North Dakota, the materials can be a great addition to any earth science or geomorphology class.

194

Geology Online Laboratory Manual  

NSDL National Science Digital Library

The 16 labs in this manual cover specific subjects from a range of topics including mineralogy, sedimentology, litho- and biostratigraphy, vertebrate and invertebrate paleontology, relative dating, and geologic map interpretation. Labs contain reference text, photos, illustrations, diagrams, and classification charts which prepare students for the accompanying exercises. Answers are not provided and labs are not designed for online interaction, but hard copies of the lab manual are available for purchase from the Georgia Perimeter College Online Bookstore. A link from the site provides ordering information and instructions.

Gore, P.; College, Georgia P.

195

A Formative Assessment of Geologic Time for High School Earth Science Students  

NSDL National Science Digital Library

Earth science courses typically include the concept of geological time. The authors of this study attempt to move past traditional assessment practices and develop a formative assessment of students' understanding of the construction of the geologic time scale and how it is interpreted. Through this approach students are challenged to conceptualize the geologic time scale by comparing it to a student-produced time scale for an older adult's life. This formative assessment allows the teacher to alter instruction based on students' feedback in order to maximize student understanding of geologic time.

2004-05-01

196

Terrestrial analogs, planetary geology, and the nature of geological reasoning  

NASA Astrophysics Data System (ADS)

Analogical reasoning is critical to planetary geology, but its role can be misconstrued by those unfamiliar with the practice of that science. The methodological importance of analogy to geology lies in the formulation of genetic hypotheses, an absolutely essential component of geological reasoning that was either ignored or denigrated by most 20th century philosophers of science, who took the theoretical/ experimental methodology of physics to be the sole model for all of scientific inquiry. Following the seminal 19th century work of Grove Karl Gilbert, an early pioneer of planetary geology, it has long been recognized that broad experience with and understanding of terrestrial geological phenomena provide geologists with their most effective resource for the invention of potentially fruitful, working hypotheses. The actions of (1) forming such hypotheses, (2) following their consequences, and (3) testing those consequences comprise integral parts of effective geological practice in regard to the understanding of planetary surfaces. Nevertheless, the logical terminology and philosophical bases for such practice will be unfamiliar to most planetary scientists, both geologists and nongeologists. The invention of geological hypotheses involves both inductive inferences of the type Gilbert termed “empiric classification” and abductive inferences of a logical form made famous by the 19th century American logician Charles Sanders Peirce. The testing and corroboration of geological hypotheses relies less on the correspondence logic of theoretical/ experimental sciences, like physics, and more on the logic of consistency, coherence, and consilience that characterizes the investigative and historical sciences of interpretation exemplified by geology.

Baker, Victor R.

2014-05-01

197

Geologic Mapping and Geologic History: Sheep Mountain, Wyoming  

NSDL National Science Digital Library

Half way through the second semester of our year-long integrated Sed/Strat and Structure course we travel to Sheep Mountain, Wyoming where the students spend 5 days describing and measuring section and the constructing geologic and structural maps. The field data gathered then form the basis for a paper titled: "Geologic History of the Sheep Mountain Region". In addition to simply making geologic maps, stratigraphic sections and structural cross-sections, the students have to put the local geology into the broader contexts of the Big Horn Basin and sequences of western orogenies.

Malinconico, Lawrence L.

198

Mobilization and speciation of arsenic from hydrothermally altered rock in laboratory column experiments under ambient conditions  

Microsoft Academic Search

This paper describes the mobilization and speciation of As found in hydrothermally altered rock under oxic column conditions. The altered rock sample was obtained from a tunnel project located in the Nakakoshi area of Hokkaido, Japan, whose geology is represented by slate, shale and sandstone. This area has undergone silicification, pyritization and argillic alteration resulting in As-enrichment of the rock.

Carlito Baltazar Tabelin; Toshifumi Igarashi; Ryohei Takahashi

199

Geological age of reactors  

NASA Astrophysics Data System (ADS)

Nuclear reactors become obsolete by wearing out or by becoming outclassed or out of date. The lifetime of a conventional power reactor is probably less that 30 years, but the life of its potentially dangerous radioactivity is now known to be of a geological time scale. When a reactor is shutdown permanently, the fuel rods, cooling water, and radioactively ‘hot’ pieces are removed for long-term storage. High-level and low-level radioactive isotopes contained in the liquids and solids removed present a special problem (see Eos, Feb. 9, 1982, p. 147). It is the main frame and construction of worn out reactors that are the major problem, however. Mainly because of neutron activation processes that occur during reactor operation, components have been found to contain nickel-59 and niobium-94, both of which have very long half-lives: 80,000 and 20,300 years, respectively. The two isotopes are only present in trace amounts in metals incorporated in reactor components, but they emit levels of radiation above acceptable levels. The result is that the entire reactors must be dismantled, reduced to shippable size pieces, and the pieces stored for geologic time periods (several half-lives).

Bell, Peter M.

200

Petroleum geology of Kuwait  

SciTech Connect

Kuwait is located in the Arabian platform geologic province and the stable shelf tectonic environment of the Mesopotamian geosyncline, a sedimentary basin extending from the Arabian shield on the west to the Zagros Mountains of complex folding and faulting history, on the east. The sedimentary cover in Kuwait consists of a complete succession 25,000 ft (7,600 m) thick on top of the basement and ranges in age from Paleozoic to Holocene. The relative geologic stability and homogeneity over virtually all its depositional history resulted in an extraordinary areal continuity of reservoirs, seals, and source rocks, giving rise to the accumulation of the largest concentration of the hydrocarbon reserves in the world in giant and super-giant oil and gas fields. The structures are very large, gentle with modest closure. The seals are very efficient. Because of the wide extent of the lithologic units and only gentle tectonic deformation, large-scale horizontal migration is very efficient and the large structures have great storage capacity.

Youash, Y.

1988-02-01

201

Geology of northeastern Montana  

USGS Publications Warehouse

A large region in northeastern Montana has never been thoroughly explored by geologists, owing to the fact that it is a part of the Great Plains and the belief that it is too monotonous and uninteresting to tempt anyone to turn aside from the pronounced geologic features a little farther west, for which Montana is noted. This region includes parts of Sheridan, Valley, Phillips, and Blaine counties. Its investigation was begun by Smith in 1908, when he made a geologic survey of the Fort Peck Indian Reservation. Beekly explored a strip of land along the Montana-North Dakota line from Missouri River to the international boundary, and Bauer examined the townships in which Plentywood and Scobey are situated. Their results are here included with those of the writer, who during the field seasons of 1915 and 1916 was engaged in an investigation of the lignite resources of the remainder of this region, which extends from a line within 12 miles of the Montana-North Dakota boundary westward about 200 miles.

Collier, Arthur J.

1919-01-01

202

The geological setting of the ultramafic-hosted Logatchev hydrothermal field (14°45?N, Mid-Atlantic Ridge) and its influence on massive sulfide formation  

NASA Astrophysics Data System (ADS)

The Logatchev hydrothermal field (14°45'N on the MAR) is one of a few submarine hydrothermal systems associated with ultramafic rocks. It is situated on the eastern inner flank of the rift valley wall, 7 km away from the spreading axis and its formation has previously been linked to detachment faulting and core complex formation. Geological mapping during various ROV dives, geological sampling, and shallow drilling reveal a structural control of hydrothermal activity as well as its location in a debris flow consisting of heterogeneous ultramafic and mafic intrusive rocks. The mixed mafic/ultramafic host rock lithology is in agreement with published vent fluid and gas chemical data showing characteristics for interaction with mafic as well as with ultramafic rocks. Massive sulfide formation is more focused than previously thought and likely limited to a thin veneer at the seafloor. The Logatchev hydrothermal field shows a number of peculiarities that are unusual for most other hydrothermal systems. One of these are so-called ,,smoking craters", seafloor depressions that are several meters wide, characterized by an elevated crater rim made up partly of sulfide talus but also of abundant wall rock material. At these smoking craters hydrothermal venting occurs directly from holes within the craters and from small, cm to dm high, Cu-rich chimneys occurring at the crater rim. Based on geological mapping and sampling we suggest that these smoking craters are the product of processes related to the regional and local geological setting in an ultramafic-hosted, off-axis location with abundant landslides, as well as off-axis gabbroic intrusions providing the heat for the hydrothermal convection cell.

Petersen, S.; Kuhn, K.; Kuhn, T.; Augustin, N.; Hékinian, R.; Franz, L.; Borowski, C.

2009-09-01

203

Geologic Map of the Valles Caldera, Jemez Mountains, New Mexico  

NASA Astrophysics Data System (ADS)

Valles caldera is famous as the type locality of large resurgent calderas (Smith and Bailey, 1968), the location of a classic 260-300 °C liquid-dominated geothermal system (Goff and Gardner, 1994), and the site of a long-lived late Pleistocene lake (Fawcett et al., 2011). We have published a detailed color geologic map of the Valles caldera and surrounding areas at 1:50,000 scale obtainable from New Mexico Bureau of Geology and Mineral Resources (geoinfo.nmt.edu/publications/maps/geologic/gm/79/). The new Valles map has been compiled from all or parts of nine 1:24,000 geologic maps completed between 2004 and 2008 (Bland, Cerro del Grant, Jarosa, Jemez Springs, Polvadera Peak, Redondo Peak, Seven Springs, Valle San Antonio, and Valle Toledo). Our map provides more detailed geology on the resurgent dome, caldera collapse breccias, post-caldera lava and tuff eruptions, intracaldera sedimentary and lacustrine deposits, and precaldera volcanic and sedimentary rocks than previous maps and incorporates recent stratigraphic revisions to the geology of the Jemez Mountains volcanic field. Three cross sections supported by surface geology, geophysical data and deep borehole logs (?4500 m) show an updated view of the caldera interior, depict a modern interpretation of caldera collapse and resurgence, and provide caldera-wide subsurface isotherms (?500 °C). A 30 page booklet included with the map contains extensive rock descriptions for 162 stratigraphic units and figures showing physiographic features, structural relations between Valles (1.25 Ma) and the earlier, comparably sized Toledo caldera (1.62 Ma), correlation charts of map units, and the distribution of pre- and post-caldera hydrothermal alteration styles, including recently documented zeolite-type alteration. Finally, the booklet includes a generalized model showing our interpretation of intracaldera structure and subjacent magma chambers, and relations of Valles to earlier Quaternary-Precambrian units.

Goff, F.; Gardner, J. N.; Reneau, S. L.; Kelley, S. A.; Kempter, K. A.; Lawrence, J. R.

2011-12-01

204

Geology of Mojave National Preserve  

NSDL National Science Digital Library

This website of the United States Geological Survey (USGS) and the National Park Service (NPS) highlights the geology of the Mojave National Preserve in California. It includes a field trip describing areas of interest at the preserve, as well as a geologic time scale describing the history and development of this area. Processes that shaped this region include volcanism, tectonics, faulting, erosion, deposition, spreading, intrusions, and glaciation. There is a geologic map of the area with units and a legend, and links to maps and technical papers.

205

Geologic processes influence the effects of mining on aquatic ecosystems  

USGS Publications Warehouse

Geologic processes strongly influence water and sediment quality in aquatic ecosystems but rarely are geologic principles incorporated into routine biomonitoring studies. We test if elevated concentrations of metals in water and sediment are restricted to streams downstream of mines or areas that may discharge mine wastes. We surveyed 198 catchments classified as “historically mined” or “unmined,” and based on mineral-deposit criteria, to determine whether water and sediment quality were influenced by naturally occurring mineralized rock, by historical mining, or by a combination of both. By accounting for different geologic sources of metals to the environment, we were able to distinguish aquatic ecosystems limited by metals derived from natural processes from those due to mining. Elevated concentrations of metals in water and sediment were not restricted to mined catchments; depauperate aquatic communities were found in unmined catchments. The type and intensity of hydrothermal alteration and the mineral deposit type were important determinants of water and sediment quality as well as the aquatic community in both mined and unmined catchments. This study distinguished the effects of different rock types and geologic sources of metals on ecosystems by incorporating basic geologic processes into reference and baseline site selection, resulting in a refined assessment. Our results indicate that biomonitoring studies should account for natural sources of metals in some geologic environments as contributors to the effect of mines on aquatic ecosystems, recognizing that in mining-impacted drainages there may have been high pre-mining background metal concentrations.

Schmidt, Travis S.; Clements, William H.; Wanty, Richard B.; Verplanck, Philip L.; Church, Stanley E.; San Juan, Carma A.; Fey, David L.; Rockwell, Barnaby W.; DeWitt, Ed H.; Klein, Terry L.

2012-01-01

206

Geologic map of Io  

USGS Publications Warehouse

Io, discovered by Galileo Galilei on January 7–13, 1610, is the innermost of the four Galilean satellites of the planet Jupiter (Galilei, 1610). It is the most volcanically active object in the Solar System, as recognized by observations from six National Aeronautics and Space Administration (NASA) spacecraft: Voyager 1 (March 1979), Voyager 2 (July 1979), Hubble Space Telescope (1990–present), Galileo (1996–2001), Cassini (December 2000), and New Horizons (February 2007). The lack of impact craters on Io in any spacecraft images at any resolution attests to the high resurfacing rate (1 cm/yr) and the dominant role of active volcanism in shaping its surface. High-temperature hot spots detected by the Galileo Solid-State Imager (SSI), Near-Infrared Mapping Spectrometer (NIMS), and Photopolarimeter-Radiometer (PPR) usually correlate with darkest materials on the surface, suggesting active volcanism. The Voyager flybys obtained complete coverage of Io's subjovian hemisphere at 500 m/pixel to 2 km/pixel, and most of the rest of the satellite at 5–20 km/pixel. Repeated Galileo flybys obtained complementary coverage of Io's antijovian hemisphere at 5 m/pixel to 1.4 km/pixel. Thus, the Voyager and Galileo data sets were merged to enable the characterization of the whole surface of the satellite at a consistent resolution. The United States Geological Survey (USGS) produced a set of four global mosaics of Io in visible wavelengths at a spatial resolution of 1 km/pixel, released in February 2006, which we have used as base maps for this new global geologic map. Much has been learned about Io's volcanism, tectonics, degradation, and interior since the Voyager flybys, primarily during and following the Galileo Mission at Jupiter (December 1995–September 2003), and the results have been summarized in books published after the end of the Galileo Mission. Our mapping incorporates this new understanding to assist in map unit definition and to provide a global synthesis of Io's geology.

Williams, David A.; Keszthelyi, Laszlo P.; Crown, David A.; Yff, Jessica A.; Jaeger, Windy L.; Schenk, Paul M.; Geissler, Paul E.; Becker, Tammy L.

2011-01-01

207

Geologic map of the Valley Mountain 15’ quadrangle, San Bernardino and Riverside Counties, California  

USGS Publications Warehouse

The Valley Mountain 15’ quadrangle straddles the Pinto Mountain Fault, which bounds the eastern Transverse Ranges in the south against the Mojave Desert province in the north. The Pinto Mountains, part of the eastern Transverse Ranges in the south part of the quadrangle expose a series of Paleoproterozoic gneisses and granite and the Proterozoic quartzite of Pinto Mountain. Early Triassic quartz monzonite intruded the gneisses and was ductiley deformed prior to voluminous Jurassic intrusion of diorite, granodiorite, quartz monzonite, and granite plutons. The Jurassic rocks include part of the Bullion Mountains Intrusive Suite, which crops out prominently at Valley Mountain and in the Bullion Mountains, as well as in the Pinto Mountains. Jurassic plutons in the southwest part of the quadrangle are deeply denuded from midcrustal emplacement levels in contrast to supracrustal Jurassic limestone and volcanic rocks exposed in the northeast. Dikes inferred to be part of the Jurassic Independence Dike Swarm intrude the Jurassic plutons and Proterozoic rocks. Late Cretaceous intrusion of the Cadiz Valley Batholith in the northeast caused contact metamorphism of adjacent Jurassic plutonic rocks. The Tertiary period saw emplacement of basanitoid basalt at about 23 Ma and deposition of Miocene and (or) Pliocene ridge-capping gravels. An undated east-dipping low-angle normal fault zone in the Pinto Mountains drops hanging-wall rocks eastward and may account for part of the contrast in uplift history across the quadrangle. The eastern Transverse Ranges are commonly interpreted as severely rotated clockwise tectonically in the Neogene relative to the Mojave Desert, but similar orientations of Jurassic dike swarms suggest that any differential rotation between the two provinces is small in this quadrangle. The late Cenozoic Pinto Mountain Fault and other strike-slip faults cut Quaternary deposits in the quadrangle, with two northwest-striking faults cutting Holocene deposits. Geographic Information System and metadata on most geologic features are available on the Geologic map of the Sheep Hole Mountains 30’ by 60’ quadrangle, U.S. Geological Survey map MF–2234, scale 1:100,000, available at http://pubs.usgs.gov/mf/2002/2344/.

Howard, Keith A.; Bacheller, John; Fitzgibbon, Todd T.; Powell, Robert E.; Allen, Charlotte M.

2013-01-01

208

Guide to the geology of Australia  

NASA Astrophysics Data System (ADS)

The geology of onshore continental Australia is presented as a series of data sheets in which each geological province or entity is described in terms of key geological parameters: age, size, margins, physiography, elements, stratigraphy, igneous activity, metamorphism, deformation, and economic geology. An outline is given of Australian landforms, and a short geological history is presented. The bulletin is designed as a reference to the geology of Australia and as a companion to regional and continent-wide geological maps.

Palfreyman, W. D.; Adkins, J. S.

209

Reading the Geology of Canada: Geological Discourse as Narrative  

Microsoft Academic Search

This article suggests that Sir Wil­ liam Logan's Geology of Canada can be read as a narrative describing the past dynamic changes that shaped the present structure of the earth. The author also suggests, since the foundation of nineteenth century geology was a bio-stratigraphic con­ sensus that combined stratigraphy and the fossil record, that the use of a narrative offered

WILLIAM E. EAGAN

210

Geological consequences of superplumes  

SciTech Connect

Superplumes are suggested to have caused the period of constant normal magnetic polarity in mid-Cretaceous time (124-83 Ma) and, possibly, the period of constant reversed polarity in Pennsylvania-Permian time (323-248 Ma). These times coincide with increases in world temperature, deposition of black shales, oil generation, and eustatic sea level in the mid-Cretaceous, and increased coal generation and gas accumulation in the Pennsylvanian-Permian, accompanied by an intracratonic Pennsylvanian transgression of epicontinental seas. These geologic anomalies are associated with episodes of increased world-wide ocean-crust production and mantle outgassing, especially of carbon and nutrients. These superplumes originated just above the core-mantle boundary, significantly increased convection in the outer core, and stopped the magnetic field reversal process for 41 m.y. in the Cretaceous and 75 m.y. in Pennsylvanian-Permian time.

Larson, R.L. (Univ. of Rhode Island, Narragansett (United States))

1991-10-01

211

Geological consequences of superplumes  

NASA Astrophysics Data System (ADS)

Superplumes are suggested to have caused the period of constant normal magnetic polarity in mid-Cretaceous time (124-83 Ma) and, possibly, the period of constant reversed polarity in Pennsylvanian-Permian time (323-248 Ma). These times coincide with increases in world temperature, deposition of black shales, oil generation, and eustatic sea level in the mid-Cretaceous, and increased coal generation and gas accumulation in the Pennsylvanian-Permian, accompanied by an intracratonic Pennsylvanian transgression of epicontinental seas. These geologic anomalies are associated with episodes of increased world-wide ocean-crust production and mantle outgassing, especially of carbon and nutrients. These superplumes originated just above the core-mantle boundary, significantly increased convection in the outer core, and stopped the magnetic field reversal process for 41 m.y. in the Cretaceous and 75 m.y. in Pennsylvanian-Permian time.

Larson, Roger L.

1991-10-01

212

Geologic mapping of Europa  

USGS Publications Warehouse

Galileo data enable the major geological units, structures, and surface features to be identified on Europa. These include five primary units (plains, chaos, band, ridge, and crater materials) and their subunits, along with various tectonic structures such as faults. Plains units are the most widespread. Ridged plains material spans a wide range of geological ages, including the oldest recognizable features on Europa, and appears to represent a style of tectonic resurfacing, rather than cryovolcanism. Smooth plains material typically embays other terrains and units, possibly as a type of fluid emplacement, and is among the youngest material units observed. At global scales, plains are typically mapped as undifferentiated plains material, although in some areas differences can be discerned in the near infrared which might be related to differences in ice grain size. Chaos material is composed of plains and other preexisting materials that have been severely disrupted by inferred internal activity; chaos is characterized by blocks of icy material set in a hummocky matrix. Band material is arrayed in linear, curvilinear, wedge-shaped, or cuspate zones with contrasting albedo and surface textures with respect to the surrounding terrain. Bilateral symmetry observed in some bands and the relationships with the surrounding units suggest that band material forms by the lithosphere fracturing, spreading apart, and infilling with material derived from the subsurface. Ridge material is mapped as a unit on local and some regional maps but shown with symbols at global scales. Ridge material includes single ridges, doublet ridges, and ridge complexes. Ridge materials are considered to represent tectonic processes, possibly accompanied by the extrusion or intrusion of subsurface materials, such as diapirs. The tectonic processes might be related to tidal flexing of the icy lithosphere on diurnal or longer timescales. Crater materials include various interior (smooth central, rough inner, and annular massif) and exterior (continuous ejecta) subunits. Structural features and landforms are shown with conventional symbols. Type localities for the units are identified, along with suggestions for portraying the features on geological maps, including colors and letter abbreviations for material units. Implementing these suggestions by the planetary mapping community would facilitate comparisons of maps for different parts of Europa and contribute to an eventual global synthesis of its complex geology. On the basis of initial mapping results, a stratigraphic sequence is suggested in which ridged plains form the oldest unit on Europa, followed by development of band material and individual ridges. Band materials tend to be somewhat older than ridges, but in many areas the two units formed simultaneously. Similarly, the formation of most chaos follows the development of ridged plains; although chaos is among the youngest materials on Europa, some chaos units might have formed contemporaneously with ridged plains. Smooth plains generally embay all other units and are late-stage in the evolution of the surface. C1 craters are superposed on ridged plains but are crosscut by other materials, including bands and ridges. Most c2 craters postdate all other units, but a few c2 craters are cut by ridge material. C3 craters constitute the youngest recognizable material on Europa. Copyright 2000 by the American Geophysical Union.

Greeley, R.; Figueredo, P. H.; Williams, D. A.; Chuang, F. C.; Klemaszewski, J. E.; Kadel, S. D.; Prockter, L. M.; Pappalardo, R. T.; Head, III, J. W.; Collins, G. C.; Spaun, N. A.; Sullivan, R. J.; Moore, J. M.; Senske, D. A.; Tufts, B. R.; Johnson, T. V.; Belton, M. J. S.; Tanaka, K. L.

2000-01-01

213

Geology orbiter comparison study  

NASA Technical Reports Server (NTRS)

Instrument requirements of planetary geology orbiters were examined with the objective of determining the feasibility of applying standard instrument designs to a host of terrestrial targets. Within the basic discipline area of geochemistry, gamma-ray, X-ray fluorescence, and atomic spectroscopy remote sensing techniques were considered. Within the discipline area of geophysics, the complementary techniques of gravimetry and radar were studied. Experiments using these techniques were analyzed for comparison at the Moon, Mercury, Mars and the Galilean satellites. On the basis of these comparative assessments, the adaptability of each sensing technique was judged as a basic technique for many targets, as a single instrument applied to many targets, as a single instrument used in different mission modes, and as an instrument capability for nongeoscience objectives.

Cutts, J. A. J.; Blasius, K. R.; Davis, D. R.; Pang, K. D.; Shreve, D. C.

1977-01-01

214

Evolution of fluid-rock interactions: fluid inclusion, isotopic, and major/minor element chemistry of hydrothermally altered volcanic rock in core RN-17B, Reykjanes, Iceland  

NASA Astrophysics Data System (ADS)

The Reykjanes Peninsula, Iceland, hosts a seawater-dominated geothermal system. Previous studies indicate an evolution of the system from meteoric to seawater. The inclined 4-inch diameter RN-17B drill core was collected from 2798.5 m to 2808.5 m (~2555 m below surface) at in situ temperature of approximately 330°C. Samples for this study were obtained from the Iceland Deep Drilling Project (IDDP). The core contains hydrothermally altered rocks of basaltic composition. Hydrothermal alteration ranges from upper greenschist to lower amphibolite grade, dependent on protolith size and composition. Veins in the core grade inward from radial epidote + acicular hornblende + titanite + pyrite, to clearer equant and compositionally zoned epidote vein centers. Felted amphibole replaces hyaloclastite and smaller crystalline clasts within the core, but is absent from the centers of crystalline pillow basalt fragments. Amphibole in vein selvages and vesicle fillings is green and acicular. Electron microprobe analyses of amphibole indicate it spans a compositional range of ferrohornblende through paragasite. The pistacite component (Xps) of vein epidote ranges from 16.5 to 36.7. The Xps component shows both normal and reverse zoning within single epidote crystals across this range, and follows no distinct pattern. Vein epidote adjacent to the wall rock has a higher aluminum concentration than vein centers. This may be due to mobilization of aluminum from plagioclase in the wall rock during albitization. Solutions flowing through open fractures may have lower Al-content and thus precipitate more Fe-rich epidote than those next to the fracture walls. Primary fluid inclusions in epidote range in size from <1 to 10 ?m in diameter. Secondary fluid inclusions are <1 ?m in diameter and not measurable. Calculated fluid inclusion salinities range from 0.5 to 7.6 weight percent NaCl, with lower salinities adjacent to the wall rock and higher salinities in the vein centers. Homogenization temperature (Th) measurements fall into 3 categories: 1) non-homogenizing adjacent to vein walls; 2) inwards of vein wall (Th = 383.6 to 401.5°C); and 3) the vein center (Th = 344.9 to 378.3°C). Laser ablation ICP-MS spot measurements of strontium isotope (87Sr/86Sr) ratios decrease from the vein edges (0.70500) to the vein centers (0.70400). 87Sr/86Sr isotope ratios are overall shifted away from oceanic basalt values towards seawater values. Lower 87Sr/86Sr ratios in the vein centers indicate an evolution of the system to lower water/rock ratios. If this conclusion is correct, lower water/rock ratio may be responsible for salinities greater than seawater in the vein centers following wall rock hydration.

Fowler, A. P.; Zierenberg, R. A.; Schiffman, P.; Marks, N. E.; Fridleifsson, G. O.

2011-12-01

215

COGS: Computer Oriented Geological Society  

Microsoft Academic Search

The Computer Oriented Geological Society (COGS), based in Denver, Colorado, is a professional organization of geologists and geophysicists that actively encourages application of computers to natural resource exploration and development. Founded in December 1982 as a user-oriented group, COGS is a network of earth scientists who both gain and contribute ideas and information regarding geologic computer applications. Dedicated to self-help

Thomson

1984-01-01

216

Coastal Processes and Offshore Geology  

Microsoft Academic Search

The modern coastal geology of Virginia results from the interactions of modern processes, primarily waves, tidal currents and sea-level rise, with the antecedent geology. The ancient and major rivers draining the Piedmont and interior highlands of eastern North America carried sediments that were deposited in various areas across the physiographic continuum of the coastal plain and continental shelf as sea

Carl H. Hobbs; David E. Krantz; Geoffrey L. Wikel

217

Catastrophe theory models in geology  

Microsoft Academic Search

Catastrophe theory is a recently developed branch of topology which has a number of practical applications, principally because of its ability to model situations which include discontinuities or singularities, where the methods of differential calculus break down. Some examples of its possible use in geology are presented, in fields as diverse as volcanology, sedimentology, and structural geology, and wider applications,

S. Henley

1976-01-01

218

National Cooperative Geologic Mapping Program  

NSDL National Science Digital Library

The National Cooperative Geologic Mapping Program (NCGMP) is "the primary source of funds for the production of geologic maps in the United States." The NCGMP was created by the National Geologic Mapping Act of 1992 and its work includes producing surficial and bedrock geologic map coverage for the entire country. The program has partnered with a range of educational institutions, and this site provides access to many of the fruits of this partnership, along with educational materials. The place to start here is the What's a Geologic Map? area. Here visitors can read a helpful article on this subject, authored by David R. Soller of the U.S. Geological Survey. Moving on, visitors can click on the National Geologic Map Database link. The database contains over 88,000 maps, along with a lexicon of geologic names, and material on the NCGMP's upcoming mapping initiatives. Those persons with an interest in the organization of the NCGMP should look at the Program Components area. Finally, the Products-Standards area contains basic information on the technical standards and expectations for the mapping work.

2012-06-13

219

Geologic mapping of Argyre Planitia  

NASA Technical Reports Server (NTRS)

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.

Gorsline, Donn S.; Parker, Timothy J.

1995-01-01

220

Geology of the Black Hills  

NSDL National Science Digital Library

This presents a virtual geology field trip of the Black Hills. The topics that are covered include the general geology of the area, engineering and environmental issues, economic uses such as gold mining and bentonite recovery, and fossils. This site also features a clickable map that displays the location, information, and photographs of interesting stops in the Black Hills.

University, South D.

221

The Geophysical Revolution in Geology.  

ERIC Educational Resources Information Center

Discussed is the physicists' impact on the revolution in the earth sciences particularly involving the overthrow of the fixist notions in geology. Topics discussed include the mobile earth, the route to plate tectonics, radiometric dating, the earth's magnetic field, ocean floor spreading plate boundaries, infiltration of physics into geology and…

Smith, Peter J.

1980-01-01

222

Computer Assisted Instruction in Geology.  

ERIC Educational Resources Information Center

The development of a computer self-test program in geology at Macalester College, Minnesota, is described. Based on the philosophy that tests, particularly those involving no grading, are useful study devices, computers are used to make tests available to students. Ten lessons have been developed on different topics in geology, and the computer…

Lepp, Henry

223

Viruses as new agents of organomineralization in the geological record.  

PubMed

Viruses are the most abundant biological entities throughout marine and terrestrial ecosystems, but little is known about virus-mineral interactions or the potential for virus preservation in the geological record. Here we use contextual metagenomic data and microscopic analyses to show that viruses occur in high diversity within a modern lacustrine microbial mat, and vastly outnumber prokaryotes and other components of the microbial mat. Experimental data reveal that mineral precipitation takes place directly on free viruses and, as a result of viral infections, on cell debris resulting from cell lysis. Viruses are initially permineralized by amorphous magnesium silicates, which then alter to magnesium carbonate nanospheres of ~80-200?nm in diameter during diagenesis. Our findings open up the possibility to investigate the evolution and geological history of viruses and their role in organomineralization, as well as providing an alternative explanation for enigmatic carbonate nanospheres previously observed in the geological record. PMID:24989676

Pacton, Muriel; Wacey, David; Corinaldesi, Cinzia; Tangherlini, Michael; Kilburn, Matt R; Gorin, Georges E; Danovaro, Roberto; Vasconcelos, Crisogono

2014-01-01

224

Usbnd Mo mineralization potential in Pan-African granites, southwestern Cameroon: Economic geology of the Ekomédion prospect  

NASA Astrophysics Data System (ADS)

Uranium and molybdenum mineralization at the Ekomédion prospect of southwestern Cameroon occurs within pegmatite pods in Pan-African two-mica granite. The two-mica granite and the associated pegmatite experienced brittle deformation. Mineralization occurs as veinlets following early fractures and as irregular bodies intimately associated with pegmatite pods. Syn-tectonic alteration comprises albitization, silicification, ferruginization, seriticitization and chloritization. Mica in the ore zone is less magnesian and F-rich relative to mica in the host two-mica granite. Uraninite crystals are anhedral to subhedral and molybdenite is commonly encapsulated by phengitic muscovite. The two-mica granite is a strongly fractionated high-K, low P ferroan granite. The pegmatite pods hosting Usbnd Mo mineralization are suggested to have been derived from the fractionation of magma parental to the two-mica granite as observed from Rare Earth Element (REE) patterns and the trend shown by Th/U ratios of the host granite and the pegmatite. This implies that uranium and molybdenum fractionated and concentrated preferentially into the late stage pegmatitic fluid that formed the pods and subsequently into the hydrothermal fluid phase. This therefore points to the two-mica granite as well as the metamorphic wall rocks as potential sources for Usbnd Mo mineralization in southwestern Cameroon.

Mosoh Bambi, C. K.; Suh, C. E.; Nzenti, J. P.; Frimmel, H. E.

2012-04-01

225

Geology of Earth's Moon  

NSDL National Science Digital Library

First, researchers at the University of California, San Diego discuss the importance of studying earthquakes on the moon, also known as moonquakes, and the Apollo Lunar Seismic Experiment (1). Users can discover the problems scientists must deal with when collecting the moon's seismic data. The students at Case Western Reserve University created the second website to address three missions the Institute of Space and Astronautical Science (ISAS) has planned between now and 2010, including a mission to the moon (2). Visitors can learn about the Lunar-A probe that will be used to photograph the surface of the moon, "monitor moonquakes, measure temperature, and study the internal structure." Next, the Planetary Data Service (PDS) at the USGS offers users four datasets that they can use to create an image of a chosen area of the moon (3). Each dataset can be viewed as a basic clickable map; a clickable map where users can specify size, resolution, and projection; or an advanced version where visitors can select areas by center latitude and longitude. The fourth site, produced by Robert Wickman at the University of North Dakota, presents a map of the volcanoes on the moon and compares their characteristics with those on earth (4). Students can learn how the gravitational forces on the Moon affect the lava flows. Next, Professor Jeff Ryan at the University of South Florida at Tampa supplies fantastic images and descriptive text of the lunar rocks obtained by the Apollo missions (5). Visitors can find links to images of meteorites, terrestrial rocks, and Apollo landings as well. At the Science Channel website, students and educators can find a video clip discussing the geologic studies on the moon along with videos about planets (6). Users can learn about how studying moon rocks help scientists better understand the formation of the earth. Next, the Smithsonian National Air and Space Museum presents its research of "lunar topography, cratering and impacts basins, tectonics, lava flows, and regolith properties" (7). Visitors can find summaries of the characteristics of the moon and the main findings since the 1950s. Lastly, the USGS Astrogeology Research Program provides archived lunar images and data collected between 1965 and 1992 by Apollo, Lunar Orbiter, Galileo, and Zond 8 missions (8). While the data is a little old, students and educators can still find valuable materials about the moon's topography, chemical composition, and geology.

226

Multi- and hyperspectral geologic remote sensing: A review  

NASA Astrophysics Data System (ADS)

Geologists have used remote sensing data since the advent of the technology for regional mapping, structural interpretation and to aid in prospecting for ores and hydrocarbons. This paper provides a review of multispectral and hyperspectral remote sensing data, products and applications in geology. During the early days of Landsat Multispectral scanner and Thematic Mapper, geologists developed band ratio techniques and selective principal component analysis to produce iron oxide and hydroxyl images that could be related to hydrothermal alteration. The advent of the Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) with six channels in the shortwave infrared and five channels in the thermal region allowed to produce qualitative surface mineral maps of clay minerals (kaolinite, illite), sulfate minerals (alunite), carbonate minerals (calcite, dolomite), iron oxides (hematite, goethite), and silica (quartz) which allowed to map alteration facies (propylitic, argillic etc.). The step toward quantitative and validated (subpixel) surface mineralogic mapping was made with the advent of high spectral resolution hyperspectral remote sensing. This led to a wealth of techniques to match image pixel spectra to library and field spectra and to unravel mixed pixel spectra to pure endmember spectra to derive subpixel surface compositional information. These products have found their way to the mining industry and are to a lesser extent taken up by the oil and gas sector. The main threat for geologic remote sensing lies in the lack of (satellite) data continuity. There is however a unique opportunity to develop standardized protocols leading to validated and reproducible products from satellite remote sensing for the geology community. By focusing on geologic mapping products such as mineral and lithologic maps, geochemistry, P-T paths, fluid pathways etc. the geologic remote sensing community can bridge the gap with the geosciences community. Increasingly workflows should be multidisciplinary and remote sensing data should be integrated with field observations and subsurface geophysical data to monitor and understand geologic processes.

van der Meer, Freek D.; van der Werff, Harald M. A.; van Ruitenbeek, Frank J. A.; Hecker, Chris A.; Bakker, Wim H.; Noomen, Marleen F.; van der Meijde, Mark; Carranza, E. John M.; Smeth, J. Boudewijn de; Woldai, Tsehaie

2012-02-01

227

The Geology of Titan  

NASA Astrophysics Data System (ADS)

Titan, the largest and most complex satellite in the solar system exhibits an organic dominated surface chemistry and shares surface features with other large icy satellites as well as the terrestrial planets. It is subject to tidal stresses, and its surface appears to have been modified tectonically. Cassini's global observations at infrared and radar wavelengths as well as local investigations by the instruments on the Huygens probe has revealed that Titan has the largest known abundance of organic material in the solar system apart from Earth, and that its active hydrological cycle is analogous to that of Earth, but with methane replacing water. The surface of Titan exhibits morphological features of different sizes and origins created by geological processes that span the entire dynamic range of aeolian, fluvial and tectonic activities, with likely evidence that cryovolcanism might exists where liquid water, perhaps in concert with ammonia, methane and carbon dioxide, makes its way to the surface from the interior [e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]. Extended dune fields, lakes, mountainous terrain, dendritic erosion patterns and erosional remnants indicate dynamic surface processes. Valleys, small-scale gullies and rounded cobbles require erosion by extended energetic flow of liquids. There is strong evidence that liquid hydrocarbons are ponded on the surface in lakes, predominantly, but not exclusively, at high northern latitudes. A variety of features including extensive flows and caldera-like constructs are interpreted to be cryovolcanic in origin. Chains and isolated blocks of rugged terrain rising from smoother areas are best described as mountains and might be related to tectonic processes. Impact craters form on all solid bodies in the solar system, and have been detected on Titan. But very few have been observed so they must be rapidly destroyed or buried by other geologic processes The morphologies of the impact craters are more similar to those seen on silicate planets than on icy satellites [22]. Removal of impact craters by burial and erosion is likely, given the evidence for fluvial and cryovolcanic processes, and the relatively degraded appearance of hills and ridges. The obvious lack of craters compared with other icy satellites indicates the surface of Titan is young and modified by volcanism and erosion. However, the existence of the large Menrva impact structure (¿400 km in diameter) suggests that in some places larger (and thus potentially older) craters can be preserved [e.g 2, 19, 20, 21, 22, 23]. In general, Titan exhibits a geologically active surface indicating significant endogenic and exogenic processes, with diverse geological, geophysical and atmospheric processes reminiscent of those on Earth [e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]. [1] Tomasko et al. 2005, Nature, 438, 765-778; [2] Porco et al. 2005, Nature, 434, 159-168; [3] Sotin et al. 2005, Nature 435, 786-789; [4] Elachi et al. 2005, Science 308, 970-974; [5] Lorenz et al. 2006, Science 312, 724-727; [6] Stofan et al. 2007, Nature,445, doi:10.10338/nature05438; [7] Lopes et al. 2007, Icarus, 186 395-412; [8] Radebaugh et al. 2007, Icarus 192, 77-92; [9] Barnes et al. 2007, JGR 112 E11006; [10] Lorenz et al. 2007, GRL 34, L07204; [11] Soderblom et al., 2007, PSS 55, 2025-2036; [12] Lorenz et al. 2008, PSS56, 1132-1144; [13] Jaumann et al. 2008, Icarus 197, 526-538; [14] Lunine et al. 2008; Icarus 195, 415-433; [15] Jaumann et al., 2009, in Titan from Cassini-Huygens, Brown et al., eds, Springer; [16] Turtle et al. 2009, GRL 36, L02204; [17] Le Corre et al., PSS 54870-879; [18] Stephan et al., 2009, in Titan from Cassini-Huygens, Brown et al., eds, Springer [19] Wood et al., 2007, LPSC, 2118; [20] Lorenz et al., 2007, GRL 34, L07204; [21] LeMouelic, et al., 2008; JGR 113, E04003; [22] Jaumann and Neukum , 2009, LPSC 1641; [23] Wood et al., 2010, Icarus 206, 334-344

Jaumann, Ralf

228

The geology of Io  

NASA Technical Reports Server (NTRS)

A preliminary geologic map of 34.8 percent of the surface of Io has been compiled using best-resolution Voyager 1 images. Nine volcanic units are identified, including materials of mountains, plains, flows, cones, and crater vents, in addition to six types of structural features. Photogeologic evidence indicates a dominantly silicate composition for the mountain material. Sulfur flows of diverse viscosity and sulfur-silicate mixtures may compose the extensive plans. Pit-crater and shield-crater vent-wall scarps reach heights of over two km, and layered-plains boundary scarps have estimated heights of 150 to 1700 m, indicating a material with considerable strength. A cumulative size-frequency distribution plot for 170 volcanic craters with diameters over 14 km is similar to the curves for impact craters on other bodies in the solar system, attesting to a similar nonrandom distribution of crater diameters and a surplus of small craters. A total of 151 lineaments and grabens forming two nearly orthogonal sets is recognized.

Schaber, G. G.

1982-01-01

229

Petroleum geology of Kuwait  

SciTech Connect

The extremely large oil reserves in Kuwait result from the presence of all conditions necessary for hydrocarbon generation, migration, entrapment, and preservation, which can be ascribed to an exceptionally large trap volume in a simple geological setting and a late expulsion and migration from a huge area of thermally mature source rocks. The Lower and middle Cretaceous sequence of Kuwait is among the world's richest hydrocarbon habitats. The depositional history is dominated by sedimentation on a very stable broad platform characterized by quiescence as reflected by a continuous deposition in a slowly subsiding sea bottom. The reservoirs are composed of thick sandstone of the Wara, Burgan, and Zubar formations. In addition to these, Mauddud Limestone forms a good reservoir in the northern fields and, in the south, the oolitic limestone of the Lower Cretaceous in Greater Burgan, Umm Gudair, and Minagish fields contains substantial hydrocarbon deposits. The sandstone reservoirs are the world's largest over 1,500 ft (450 m) in thickness of perfect reservoir quality and composed of well-sorted, medium to coarse-grained sands that were deposited in a littoral or on the edge of a deltaic and coastal environment. The source rocks are mostly likely the same reservoir rocks, particularly with downdip more shaly development of widespread thermally mature organic rich facies juxataposed with a carbonate-sandstone shelf.

Youash, Y.

1988-01-01

230

Coyote Creek Geologic Map  

NSDL National Science Digital Library

Students are required to make field observations, collect data and then create a detailed geologic map and report for a small area (approximately 1 sq. mile) on the edge of the Tularosa Basin in south central New Mexico. The study area is located within the Tularosa NE quadrangle, but maps from the Cat Mountain quadrangle to the East are also useful. Gently dipping carbonate and siliciclastic beds, igneous intrusions, bioherms and a normal fault are present in the study area along Coyote Creek, a few miles north of Tularosa, NM. The creek generally runs parallel to dip, allowing relatively easy access to inclined strata. Bioherm(s) are present in the lower section. Several dikes are present running both parallel and perpendicular to sedimentary bed strike. One is very non-resistant to weathering, creating unusual troughs as it passes through the carbonate bioherms. A sill is present in the upper section and a N/S trending normal fault roughly parallels strike of sedimentary beds.

Walsh, Timothy R.

231

COMPARING SPACEBORNE ERS-SAR AND AIRBORNE GEOPHYSICAL DATA: APPLICATION TO GEOLOGY IN THE FRENCH GUIANA RAINFOREST LANDSCAPES  

Microsoft Academic Search

Schematically French Guiana geological setting comprises essentially Palaeoproterozoic terrains, which are deeply altered under a humid tropical climate. In July and December 1996 the French Geological Survey (BRGM) working for the French Ministry of Industry supervised an airborne geophysical survey combining magnetism and spectrometry measurements, practically flown by CGG (Compagnie Générale de Géophysique). The objectives were (i) the realisation of

J. P. Deroin; C. Delor; C. Truffert; J. P. Rudant

232

Guide to the Geology of Australia.  

National Technical Information Service (NTIS)

The geology of onshore continental Australia is presented as a series of data sheets in which each geological province or entity is described in terms of key geological parameters: age, size, margins, physiography, elements, stratigraphy, igneous activity...

W. D. Palfreyman J. S. Adkins

1984-01-01

233

Geologic Setting of the Hamme Tungsten District, North Carolina and Virginia  

USGS Publications Warehouse

The Hamme tungsten district is in the eastern part of the Piedmont province, mainly in Vance County, North Carolina, but it extends a few miles into Virginia. The district is underlain by a central lenticular pluton of albite granodiorite that trends north-northeastward and is flanked on both sides by metamorphic rocks of low and medium grade that dip steeply westward. The relative ages of the metamorphic rocks are uncertain. The oldest rocks are likely to be the biotite gneisses in the eastern part of the district; successively younger units expose westward across the district are sericite-chlorite phyllites, greenstone, metafelsites, and metabasalts. The biotite gneisses and minor intercalated hornblende gneiss, which have a total thickness of many thousand feet, were derived from sediments. Some of the gneiss grades into phyllites and as probably formed by metasomatic alteration of the phyllites. Sericite-chlorite phyllite, epidote-quartz meta siltstone, quartzite, and conglomeratic phyllite occur principally in a wide belt on the west side of the central albite granodiorite. This unit is some 10,000 feet thick and originally consisted mainly of sediments of the graywacke suite. Greenstone totaling about 500 feet in thickness lies west of the phyllite and was derived from maflc lava flows and andesitic tuff. Metamorphosed massive aphanitic and porphyritic flows and dikes that range in composition from dacite to rhyolite, and phyllitic metatuffs and tuffaceous breccia are exposed west of the greenstone. These total at least 3,000 feet in thickness. Massive metabasalt that resembles greenstone but is less altered is common in the area between the Hamme district and the Virgilina district to the west. The thickness of the metabasalt is about 600 to 6,000 feet. The metamorphic rocks of the Hamme and Virgilina districts are parts of the Carolina slate belt, but map units cannot be directly correlated. Rocks in the Hamme district are thought by the writer to have been derived mainly from graywackes and volcanic flows, and subordinately from pyroclastic materials, whereas the rocks of the Virgilina district were interpreted by earlier workers as being mainly volcanic with much pyroclastic material but little sediment. Igneous, and perhaps pseudo igneous, rocks in the district include hornblende gabbro, albite granodiorite, aplite, and pegmatite--all of which are probably middle Paleozoic in age--and diabase and hypersthene tonalite of Late Triassic age. The gabbro forms three lenticular to subcircular bodies up to 2% miles in width in the western part of the area. Albite granodiorite forms a pluton with a maximum width of 7 miles which occupies the center of the area. At its northeastern end the pluton narrows abruptly to a point. Phyllite forms the wall rocks on all sides of the albite granodiorite. The contact is gradational and conformable in most places, but on the northwest side it cuts across wall structure for about 3 miles. Near its western edge the albite granodiorite includes a northeast-trending zone of schistose wall rock in and near which are localized the tungsten deposits. The origin of the albite granodiorite is uncertain, but it may have formed by the metasomatic replacement of the wallrocks, during which albite porphyroblasts developed first and were followed by microcline and quartz. Diabase and hypersthene tonalite occur as dikes and sills along four northward-trending belts. The dikes are a few feet to more than 300 feet thick, and several extend along strike for more than 10 miles. The Hamme district Is in the eastern part of the Carolina slate belt, and the Virg1l1na district lies along the western side of the belt. Rocks in the Hamme district dip mostly westward and in the Vifg1lina district dip mainly eastward into a syncline. This syncline, here named the Spewmarrow syncline, may be a structure of regional significance. Tungsten in the Hamme district occurs mainly

Parker, John Mason

1963-01-01

234

Numerical Modelling of Geological Heterogeneity - Implications for CO2 Geological Storage  

NASA Astrophysics Data System (ADS)

CO2 geological storage is a proposed mitigation strategy currently being considered to reduce atmospheric greenhouse gas emissions. One factor often limiting the implementation of CO2 geological storage is the uncertainty associated with geological heterogeneities within storage reservoirs and how these heterogeneities will impact CO2 partitioning into the various storage mechanisms. Numerical models are a useful tool for integrating field and laboratory data to generate predictions on the extent of CO2 storage at larger spatial and temporal scales than experimental work is capable of undertaking alone. Numerical models use governing equations to simulate physical and chemical processes, such as the flow and transport of CO2 within the subsurface. Governing equations require the specification of a number of input parameters inherent to the porous medium. In nature, parameters such as porosity and permeability vary within and between different rock types, according to variations in factors such as grain size, sorting, cementation and structure. These variations lead to geological heterogeneity at a number of scales. However, geological heterogeneity is often oversimplified in numerical models, either due to a lack of geological data or to increase computational efficiency. Grid spacing is often coarse, leading to faster simulation times but a decrease in numerical accuracy. Further work is required to investigate how simplifying geological heterogeneity within numerical models affects short and long term CO2 storage predictions. To quantify the impact of geological heterogeneity, TOUGH2, a multiphase flow and transport code, is used to construct a series of simulations with increasing degrees of geological complexity. Comparisons are made between numerous scenarios, including discrete versus gradual progression into areas of heterogeneous rock types, continuous versus discontinuous layering, internal structures and anisotropy. Input parameters associated with different rock types are varied within reasonable ranges and grid spacing is refined to determine the sensitivity of the models to grid size. Variations between simulations are used to determine the differences in the partitioning of CO2 between its various storage mechanisms, and whether the differences are reflective of heterogeneities in the real system or attributed to numerical error. Initial results indicate that variations in certain parameters are more significant than others in terms of the movement and partitioning of CO2 into its various storage mechanisms. Variations in horizontal to vertical permeability contrasts, and residual liquid and gas saturation have significant impacts on the flow path of CO2 through the system, and therefore the amount of CO2 that becomes trapped residually within the pore spaces or dissolves into the formation brine. Gradual changes in heterogeneity do not seem to alter the results significantly in comparison to discrete changes, indicating that modelling heterogeneities as discrete bodies is an adequate assumption. Results imply that certain geological heterogeneities and associated parameters require more accurate representation then others when considering how CO2 will be stored within the subsurface. Although finer grid sizes increases the numerical accuracy of simulations, acute grid refinement may not be required for all purposes.

Hermanson, J. L.; Kirste, D. M.

2012-12-01

235

Mineral resources, geological structure, and landform surveys  

NASA Technical Reports Server (NTRS)

Diagnostic ERTS imagery has been used to pinpoint surface conditions associated with known mining districts. These include enhancements which depict hitherto unrecognized surface alteration and allow analysis of ore-controlling fractures distribution in a regional context. ERTS has likewise provided observational data containing previously unrecognized surface anomalies in large oil-producing basins which correlate closely with known oil fields. These observational data offer promise of providing new and powerful techniques for oil exploration, especially if further work using more sophisticated enhancement-processing proves capable of emphasizing the anomalies. ERTS is showing a better-than-anticipated potential for producing accurate small-scale (large-area) geologic maps, often containing details that were previously not recorded on similar regional maps. The maps produced from ERTS imagery can be prepared more effectively than previously possible, mainly because of the synoptic, multispectral, and repetitive character of ERTS data. ERTS has also provided extensive information on possible geologic hazards. Many new fractures have been identified in several regions of the Pacific Coast seismic belt that have histories of recent earthquakes. This has obvious implications for engineering projects such as dams, aqueducts, and transportation routes. In the mid-continent area, ERTS data have been used to predict zones of rooffall danger in a working coal mine from newly discovered lineations (probably fractures) used as indicators of hazards.

Short, N. M.

1974-01-01

236

Washington Division of Geology and Earth Resources  

NSDL National Science Digital Library

This website contains information about the geology of Washington State, provided by the Division of Natural Resources (DNR). It includes details about geologic hazards, such as earthquakes, volcanoes, landslides, tsunamis, and coal mine subsidence; geologic mapping, including a geologic map of the state; mine reclamation programs and energy regulation; downloadable publications; geology of the state by region, and by major geologic events from the Precambrian to Cenozoic; and information about the library with a Digital Bibliography of the Geology and Mineral Resources of Washington. The education section contains the Earth Connections series with lessons and experiments relating to geology within Washington state. There are many links provided for more information.

237

North Central Regional geologic characterization report. Volume 1. Final report  

SciTech Connect

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geologic factor and variables include deep mines and quarries, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, groundwater resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies. A discussion is also presented of the relationship between the US Department of Energy Siting Guidelines (10 CFR 960) and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process. 43 figs., 15 tabs.

Not Available

1985-08-01

238

Northeastern Regional geologic characterization report. Volume 1. Final report  

SciTech Connect

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. For each of the states within the Northeastern Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geologic factor and variables include deep mines and quarries, rock mass extent, postemplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major ground-water discharge zones, ground-water resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crusal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline bodies; ground-water resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies. A discussion is also presented on the relationship between the US Department of Energy (DOE) Siting Guidelines (10 CFR 960) and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process.

Not Available

1985-08-01

239

Tethys geology and tectonics revisited  

NASA Technical Reports Server (NTRS)

Tethys, a medium sized icy satellite of Saturn, was imaged by both Voyager 1 and 2 spacecraft at sufficiently high resolution to allow some geologic analysis. One fairly complete and several brief descriptions of Tethys' geology have been given. Partial results are given herein of a new analysis of Tethys' geology done as part of a comparative tectonic and cryovolcanic study of the saturnian satellites. A new geologic sketch map of Tethys' north polar area is given. This map is based on a sequence of images transformed to a polar stereographic projection at the same scale. The images present the same area under different illuminations, each of which brings out different features. A new global map is in progress.

Croft, Steven K.

1991-01-01

240

Perspectives in geology. Circular 525  

SciTech Connect

The papers in this symposium present diverse perspectives in geology, mineral resources, paleontology, and environmental concerns. Papers within the scope of EDB have been entered individually into the data base. (ACR)

Not Available

1982-01-01

241

Terrestrial and Lunar Geological Terminology  

NASA Technical Reports Server (NTRS)

This section is largely a compilation of defining geological terms concepts. Broader topics, such as the ramifications for simulant design and in situ resource utilization, are included as necessary for context.

Schrader, Christian

2009-01-01

242

Internet Community for Geological Engineers  

NSDL National Science Digital Library

A site containing multiple resources for geological engineers. Contains current news headlines in oil, energy, and mining; information on borehole breakouts, hydraulic fracturing, core discing, pressurized slot testing, nuclear high level waste disposal, and water infrastructure security.

2008-10-06

243

JiTT - Geologic Dating  

NSDL National Science Digital Library

1) How are zircons formed? 2) Which of the following statements describes relative geologic dating? a) the Triceratops and Tyrannosaurus rex went extinct at the same time b) dinosaurs came later than horseshoe ...

Guertin, Laura

244

Chapter 4: Geological Carbon Sequestration.  

National Technical Information Service (NTIS)

Carbon sequestration is the long term isolation of carbon dioxide from the atmosphere through physical, chemical, biological, or engineered processes. The largest potential reservoirs for storing carbon are the deep oceans and geological reservoirs in the...

J. Friedmann H. Herzog

2006-01-01

245

A primer in lunar geology  

NASA Technical Reports Server (NTRS)

Primary topics in lunar geology range from the evolution of the solar system to lunar photointerpretation, impact crater formation, and sampling to analyses on various Apollo lunar landing site geomorphologies.

Greeley, R. (editor); Schultz, P. H. (editor)

1974-01-01

246

Central American geologic map project  

SciTech Connect

During the Northeast Quadrant Panel meeting of the Circum-Pacific Map Project held in Mexico City, February 1985, Central American panel members proposed and adopted plans for compiling a geologic map of Central America, probably at a scale of 1:500,000. A local group with participants from each country was organized and coordinated by Rolando Castillo, director, Central American School of Geology, University of Costa Rica, for the geologic aspects, and Fernando Rudin, director, Geographic Institute of Costa Rica, for the topographic base. In 1956, the US Geological Survey published a geologic map of the region at a scale of 1:1 million. Subsequent topographic and geologic mapping projects have provided a large amount of new data. The entire area is now covered by topographic maps at a scale of 1:50,000, and these maps have been used in several countries as a base for geologic mapping. Another regional map, the Metallogenic Map of Central America (scale = 1:2 million), was published in 1969 by the Central American Research Institute for Industry (ICAITI) with a generalized but updated geologic base map. Between 1969 and 1980, maps for each country were published by local institutions: Guatemala-Belize at 1:500,000, Honduras at 1:500,000, El Salvador at 1:100,000, Nicaragua at 1:1 million, Costa Rica at 1:200,000, and Panama at 1:1 million. This information, in addition to that of newly mapped areas, served as the base for the Central American part of the Geologic-Tectonic Map of the Caribbean Region (scale = 1:2.5 million), published by the US Geological Survey in 1980, and also fro the Northeast Quadrant Maps of the Circum-Pacific Region. The new project also involves bathymetric and geologic mapping of the Pacific and Caribbean margins of the Central American Isthmus. A substantial amount of new information of the Middle America Trench has been acquired through DSDP Legs 67 and 84.

Dengo, G.

1986-07-01

247

Prediction of Exogenic Geological Processes  

Microsoft Academic Search

Prediction of exogenic geological processes (EGP) involves scientifically substantiated forecasting of events in space and\\u000a time under the action of natural and anthropogenically induced factors. The goal of the EGP prediction is to give the answers\\u000a to the three basic questions — where, when and of which activity (size) one or another type of exogenic geological process\\u000a can happen, and

Arkady Sheko; Vladimir Krupoderov

248

Bedrock geologic map of Vermont  

USGS Publications Warehouse

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.

Ratcliffe, Nicholas M.; Stanley, Rolfe S.; Gale, Marjorie H.; Thompson, Peter J.; Walsh, Gregory J.; With contributions by Hatch, Norman L., Jr.; 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

249

An overview of Venus geology  

NASA Astrophysics Data System (ADS)

The Magellan spacecraft is producing comprehensive image and altimetry data for the planet Venus. Initial geologic mapping of the planet reveals a surface dominated by volcanic plains and characterized by extensive volcanism and tectonic deformation. Geologic and geomorphologic units include plains terrains, tectonic terrains, and surficial material units. Understanding the origin of these units and the relation between them is an ongoing task of the Magellan team.

Saunders, R. S.; Arvidson, R. E.; Head, J. W.; Schaber, G. G.; Stofan, E. R.; Solomon, S. C.

1991-04-01

250

The Bureau of Economic Geology  

NSDL National Science Digital Library

The homepage of the Texas Bureau of Economic Geology provides links to information on the Bureau's research and industrial associates programs, its publications, news and events, and presentations by Bureau staff. A section for teachers and students includes on-line learning modules, which investigate earth science topics including soils, meteorites, floods and oil wells, as well as a coastal monitoring program for high school students and publications of general interest on Texas geology.

251

Geological assessing of urban environments with a systematic mapping survey: The 1:5000 urban geological map of Catalonia  

NASA Astrophysics Data System (ADS)

The ground features of urban areas and the geologic processes that operate on them are, in general, strongly altered from their natural original condition as a result of anthropogenic activities. Assessing the stability of the ground, the flooding areas, and, the health risk as a consequence of soil pollution, are, among others, fundamental topics of urban areas that require a better understanding. The development of systematic urban geological mapping projects provides valuable resources to address these issues. Since 2007, the Institut Geologic de Catalunya (IGC) runs an urban geological mapping project, to provide accurate geologic information of county capitals and towns of more than 10000 inhabitants of Catalonia. The urban zones of 131 towns will be surveyed for this project, totalizing an area of about 2200 km2 to be mapped in 15 years. According to the 2008 census, the 82 % of the population of Catalonia (7.242.458 inhabitants) lives in the areas to be mapped in this project. The mapping project integrates in a GIS environment the following subjects: - Data from pre-existing geotechnical reports, historical geological and topographical maps and, from historical aerial photographs. - Data from available borehole databases. - Geological characterization of outcrops inside the urban network and neighbouring areas. - Geological, chemical and physical characterisation of representative rocks, sediments and soils. - Ortophotographs (0.5 m pixel size) and digital elevation models (5 meter grid size) made from historical aerial photographs, to depict land use changes, artificial deposits and geomorphological elements that are either hidden or destroyed by urban sprawl. - Detailed geological mapping of quaternary sediments, subsurface bedrock and artificial deposits. - Data from subsurface prospection in areas with insufficient or confuse data. - 3D modelling of the main geological surfaces such as the top of the pre-quaternary basement. All the gathered data is harmonised and stored it in a database. The analysis of the database allows to compile and print the 1:5000 scale urban geological map according to the 1:5000 topographic grid of Catalonia. The map is composed by a principal map, geologic cross sections and several complementary maps, charts and tables. Regardless of the geological map units, the principal map also includes the main artificial deposits (such as infilled river valleys and road embankments), very recent or current superficial deposits, contours of outcropping areas, structural data and other relevant information gathered in stations, sampling points, boreholes indicating the thickness of artificial deposits and the depth of the pre-quaternary basement, contour lines of the top of the pre-quaternary basement surface and, water level data. The complementary maps and charts may change depending on the gathered data, the geological features of the area and the urban typology. However, the most representative complementary maps that includes the printed urban map are the quaternary subsurface bedrock map and the isopach map of thickness of quaternary and anthropogenic deposits. The map also includes charts and tables of relevant physical and chemical parameters of the geological materials, harmonised downhole lithological columns from selected boreholes, and, photographs and figures illustrating the geology of the mapped area and how urbanisation has changed the natural environment. The object of this systematic urban mapping survey is to provide a robust database to be used in targeted studies related to urban planning, geoengineering works, soil pollution and other important environmental issues that society should deal in the future.

Vilà, Miquel; Pi, Roser; Cirés, Jordi; de Paz, Ana; Berástegui, Xavier

2010-05-01

252

Geology of the Spirit landing site in Gusev crater  

NASA Astrophysics Data System (ADS)

Spirit, the first Mars Exploration Rover, successfully landed in a low albedo portion of Gusev crater at 14.5692S, 175.4729E. The landing site is a generally low relief somewhat rocky plain dominated by shallow circular depressions and low ridges. Hills ˜ 2 km to the east are over 100 m high and the rim of a 200 m diameter crater form the horizon 240 m to the northeast. The shallow circular depressions generally have rocky rims and smooth soil filled centers and may be secondary impact craters. The red soils appear to be cemented fines and sand (coarse and fine) and granules have been sorted into aeolian bedforms (many appear to be ripples with coarser granules at their crests). The albedo of the landing site is ˜ 0.19 likely due to the removal of bright, fine grained dust via dust devils. Preliminary rock counts suggest ˜ 5% of the surface is covered by rocks (varies by a factor of two in the scene), which is substantially less than at any of the three previous landing sites, although the size-frequency distribution follows a similar exponential. Boulder and cobbles are rare; the largest rock within 10 m of the lander is only ˜ 0.3 m diameter and there are substantially more pebbles <0.04 m diameter. Most of these characteristics (a safe and trafficable surface generally similar in reddish color to the three previous landing sites albeit with substantially fewer rocks) were correctly predicted from remote sensing data and models during landing site selection. Most rocks appear angular and many appear fractured and/or fragmented, consistent with impact ejecta, although more rounded rocks may also be present. Many small rocks appear embedded and cemented in the soil, suggestive of a crusted gravel armor or lag. The redder patination along the base of some rocks may be a former soil horizon and argues for net deflation at the site. A vast majority of the rocks appear dark, fine grained, and pitted. Many appear to be ventifacts, with flutes and grooves formed by impacting sand in saltation. Most rocks appear coated with dust and some lighter toned (``white'') rocks may have a thick rind of dust or soil. The chemistry and mineralogy of the rocks described elsewhere (and the pits as vesicles) appear to be consistent with olivine basalts and the soil appears similar to soil elsewhere on Mars. No clear evidence of fluvial or lacustrine activity has been identified and observations made during the first 6 weeks by Spirit argue the surface is dominated by impact and eolian processes. At the time of writing (sol 50), the rover is traversing northeast to a 200 m diameter crater to sample the ejecta and inspect interior deposits and wall rocks for a better understanding of the geologic history.

Golombek, M.; Athena Science Team

253

Relative Geologic Time and the Geologic Time Scale  

NSDL National Science Digital Library

Students are given a short introduction to fossils, strata, Steno's law of superposition, and the development of the geologic time scale from initial description of systems, through the realization that fossils could be used to correlate between systems, to the assembly of the modern geologic time scale. Then, each student in the course is given a sheet of paper with a simple stratigraphic column and associated fossils representing a geologic system on one side and a short description of the location and history of discovery of the system on the other. On a large wall, students then assemble four geologic columns from their systems representing mainland Europe, Great Britain, the Eastern U.S. and the Western U.S. using the fossils illustrated on their sheets to correlate systems. The instructor guides this process by placing the first system on the wall and by providing some narration as the columns take shape. Europe and Great Britain are assembled first, one sheet at a time, providing when completed the framework of the modern geologic time scale. Once this is up on the wall, the remaining students can assemble the other two columns in minutes using fossils to correlate between American and European systems. A temporal gap in the Grand Canyon sequence provides an opportunity to discuss the incompleteness of the rock record in any one place and a system composed of igneous and metamorphic rocks with no fossils is used to point out the difference between radiometric (absolute) and biostratigraphic (relative) dating.

Bennington, Bret

254

The Necessity of Geologic Disposal  

SciTech Connect

Nuclear wastes are the radioactive byproducts of nuclear power generation, nuclear weapons production, and other uses of nuclear material. Experts from around the world agree that deep geologic disposal of nuclear waste in a mined repository is the most environmentally sound means of removing these potential sources of radiation from interaction with the biosphere. Of the 360 millirem of background radiation received annually by the average American, from both natural and man-made sources, less than 1 millirem results from the nuclear fuel cycle. Spent nuclear fuel and high-level radioactive waste, destined for geologic disposal, are located at 126 sites in 39 states. The proposed repository site at Yucca Mountain, Nevada, is far more isolated from the general population than any sites where these radioactive materials are presently located. Only solid forms of high-level wastes will be transported for disposal in a geologic repository. For more than 50 years, nuclear materials have been safely transported in North America, Europe, and Asia, without a single significant radiation release. Since the 1950s, select panels from the National Academy of Sciences-National Research Council and interagency advisory groups, and international experts selected by the OECD/Nuclear Energy Agency, have examined the environmental, ethical, and intergenerational aspects of nuclear waste disposal, plus alternatives to geologic disposal. All have concluded that deep geologic disposal in a mined repository is clearly the preferred option. The concept of deep geologic disposal is based on the analogy to ore deposits, which are formed deep within the Earth's crust, commonly remain isolated from the biosphere for millions to billions of years, and are, generally, extremely difficult to detect. Before selecting the unsaturated tuffs at Yucca Mountain, DOE evaluated salt formations, basalts, and both crystalline and sedimentary rocks. Other nations generating nuclear power also plan to use deep geologic disposal, and are evaluating sites in granites, argillaceous rocks, and salt formations.

R. Linden

2004-07-01

255

Conversion of geologic quadrangle maps to geologic coverages  

USGS Publications Warehouse

Three hundred sixty-eight geologic map$ of 7-1/2 minute quadrangles in Tennessee were coverted to geographic information system (GIS) coverages. The procedure used was documented and a list was made of the quadrangles included in the coverages. Maps were converted to GIS coverages by making film copies of scribecoats of the maps. The film copies were scanned, vectorized, and written into a generate format. Coverage polygons were tagged with symbels to identify geologic units, and coverage lines were tagged with line types to designate stratigraphic contacts.

Connell, Joseph F.; Barron, William R.; Mitchell, Reavis L.

1994-01-01

256

Geology Fieldnotes: Guadalupe Mountains National Park, Texas  

NSDL National Science Digital Library

This Guadalupe Mountains National Park site contains park geology information, park maps, photographs, related links, visitor information, multimedia resources, and teacher features (resources for teaching geology with National Park examples). The park geology section discusses the geologic history of Guadalupe Mountains' ancient marine fossil reef and the structural geology of the Mountains' Western Escarpment (including the Frijole Ranch area, the Pine Springs area, and the Capitan Limestone structures). The park maps section includes a map of the Capitan Reef today.

257

Geology Fieldnotes: Petrified Forest National Park, Arizona  

NSDL National Science Digital Library

Petrified Forest National Park was established to preserve large deposits of petrified wood and to prevent removal of the wood by the public. Site featues include park geology information, maps, photographs, related links, visitor information, multimedia resources, and resources for teaching geology with National Park examples. The park geology section discusses the park's geologic history, structural geology, petrified wood, and dinosaur fossils. The maps section includes a map of the park itself and the surrounding area.

258

78 FR 57877 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...  

Federal Register 2010, 2011, 2012, 2013

...Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological...planning and implementation of the geologic mapping and data preservation programs. The Committee...the purposes of the National Geological Mapping Act of 1992, as well as updates on...

2013-09-20

259

Shuttle Imaging Radar - Geologic applications  

NASA Technical Reports Server (NTRS)

The Space Shuttle, on its second flight (November 12, 1981), carried the first science and applications payload which provided an early demonstration of Shuttle's research capabilities. One of the experiments, the Shuttle Imaging Radar-A (SIR-A), had as a prime objective to evaluate the capability of spaceborne imaging radars as a tool for geologic exploration. The results of the experiment will help determine the value of using the combination of space radar and Landsat imagery for improved geologic analysis and mapping. Preliminary analysis of the Shuttle radar imagery with Seasat and Landsat imagery from similar areas provides evidence that spaceborne radars can significantly complement Landsat interpretation, and vastly improve geologic reconnaissance mapping in those areas of the world that are relatively unmapped because of perpetual cloud cover.

Macdonald, H.; Bridges, L.; Waite, W.; Kaupp, V.

1982-01-01

260

Early Proterozoic geology of Arizona  

NASA Astrophysics Data System (ADS)

The Early Proterozoic geology of Arizona and adjoining regions was the topic of a workshop convened by Clay M. Conway (U.S. Geological Survey (USGS), Flagstaff, Ariz.), Karl E. Karlstrom (Northern Arizona University (NAU), Flagstaff), and Leon T. Silver (California Institute of Technology (Caltech), Pasadena) in Flagstaff, October 3-5, 1985. The meeting, sponsored by USGS, NAU, Caltech, and the Arizona Geological Survey, was attended by 73 geologists from industry, academia, and governmental agencies. The workshop brought together for the first time workers in a variety of disciplines who have been studying facets of Early Proterozoic crustal evolution in the southwest. From responses during and following the workshop, we judge that the meeting successfully accomplished its objective of furthering communication, cooperation, and collaboration. The meeting encouraged contributions, including progress reports, from all participants and concentrated on specific problems of stratigraphy, structure, petrology, geochemistry, and ore formation, with a view toward understanding overall orogenic evolution and continental accretion.

Conway, Clay M.; Karlstrom, Karl E.

261

Physical Geology: Idaho Field Trip  

NSDL National Science Digital Library

This optional field trip is designed to augment the in-class learning experience in introductory physical geology by providing students the opportunity to see firsthand local geological features and understand their context in the long-term tectonic evolution of the western United States. The university is conveniently located in a portion of the American west where a plethora of geological features are readily accessible over a total field trip duration of 6 hours. Over a total of 6 field stops, students are presented with an opportunity to observe features relevant to topics learned in class involving rock types, volcanic features (lava flows and ash fall deposits), faults and folds, mass wasting features, catastrophic flood deposits (Bonneville and Missoula floods), and loess deposits.

Kattenhorn, Simon

262

Bedrock Geologic Map of Maine  

NSDL National Science Digital Library

In this activity students study a map of bedrock geology which describes the types of rocks that exist in a given area. It shows these rock units as well as their known and inferred contacts. Consideration is also given to folding, faulting, unconformities, and similar rock relationships. These features are often included in bedrock geology maps. Students study the legend and scale and become aware of the other information that is included on the map such as the stratigraphic column, list of formations, and inset map of metamorphic grade. Students then locate their city or town and draw a 40-mile diameter circle around it and identify all the symbols inside the circle and the age of the various rocks. Student question sheets are available at this site. Although this activity was written for a map of Maine, it will work in any state where geological maps are available.

263

A Geological Wonder: Niagara Falls  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 9-12. It focuses on the geological history of the Niagara Falls area, as well as the physical and geological processes that have formed this region. It includes objectives, materials, procedures, discussion questions, evaluation ideas, performing extensions, suggested readings, and vocabulary. There are videos available to order which complement this lesson, audio vocabulary, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

264

Geology on a Sand Budget  

NSDL National Science Digital Library

Earth science teaches know how frustrating it can be to spend hundreds of dollars on three-dimensional (3-D) models of Earth's geologic features, only to use the models for a few class periods. To avoid emptying an already limited science budget, teachers can use a simple alternative to the expensive 3-D models--sand. Modeling geologic processes and features with sand is an effective way for teachers to promote student understanding of Earth science topics, quickly assess students' prior knowledge, and identify common misconceptions.

Kane, Jacqueline

2004-09-01

265

Society for Sedimentary Geology (SEPM)  

NSDL National Science Digital Library

The Society for Sedimentary Geology (SEPM) "is dedicated to the dissemination of scientific information on sedimentology, stratigraphy, paleontology, environmental sciences, marine geology, hydrogeology, and many additional related specialties." The website presents the latest and upcoming meetings, workshops, and other events. Individuals can find newsletters of the many SEPM sections and information on publications. Users can learn about the scientific achievements of many geologists in the Awards & Metals link. Students and researchers can discover the benefits of a SEPM membership including short courses and field trip opportunities.

266

Geology Programs and Disciplinary Accreditation  

NSDL National Science Digital Library

This report raises the question of whether accreditation may be coming to the geology discipline, and attempts to quantify the positions on accreditation of academic department heads/chairs. The study makes a distinction between institutional and specialized (or disciplinary) accreditation and explores attitudes toward both types. Results of the analysis are presented with a discussion of two methods of data interpretation, a multivariate analysis technique and the Chi square test for heterogeneity or independence. The report concludes that there is currently insufficient support for establishing disciplinary accreditation in geology.

Corbett, Robert; Corbett, Erica

2001-03-01

267

Learning Geology by Writing about the History of Geology.  

ERIC Educational Resources Information Center

Author describes her first-year seminar in history of geology where students are given writing assignments asking them to summarize, describe, explain, be convincing to reader. Students review their written work through frequent revision, peer review, collaborative writing assignments. Assignments require students to examine scientific principles…

Schneiderman, Jill Stephanie

1991-01-01

268

Southeastern Regional geologic characterization report. Volume 1. Final report  

SciTech Connect

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in central Maryland; noncoastal Virginia, North Carolina, and South Carolina; and northern Georgia. For each of the states within the Southeastern Region, information is provided on the geological disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geological factor and variables include deep mines and quarries, rock mass extent, postemplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major ground-water discharge zones, ground-water resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on the age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline bodies; ground-water resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies.

Not Available

1985-08-01

269

US Geological Survey Fact Sheets  

NSDL National Science Digital Library

The US Geological Survey (USGS) Fact Sheets Web site summarizes research and investigations done by the agency and provides details about particular activities. The sheets are organized by theme, including resources, hazards, environment, information management, by individual state, and by scientific discipline. The fact sheets give basic summations of the research and provide links to more detailed pages for those seeking further information.

2001-01-01

270

Geology on a Sand Budget  

ERIC Educational Resources Information Center

Earth science teachers know how frustrating it can be to spend hundreds of dollars on three-dimensional (3-D) models of Earth's geologic features, to use the models for only a few class periods. To avoid emptying an already limited science budget, the author states that teachers can use a simple alternative to the expensive 3-D models--sand. She…

Kane, Jacqueline

2004-01-01

271

Geology and the dark side  

Microsoft Academic Search

The diabolical and supernatural folklore traditions of geology are examined systematically for the first time. The following have all been suggested explanations for fossil remains: Devil's footprints, bones, toenails, fingers, thumbs, buttons, money and ninepins; Hobgoblin's claws; Fairy's fingers, heads, faces, hearts, beads, causeways, saltcellars, bottles, weights, money and loaves; elf arrows; witches’ beads and tongues. Twinned staurolite crystals have

Christopher J. Duffin; Jane P. Davidson

2011-01-01

272

Briefing on geological sequestration (Tulsa)  

EPA Science Inventory

Geological sequestration (GS) is generally recognized as the injection and long-term (e.g., hundreds to thousands of years) trapping of gaseous, liquid or supercritical carbon dioxide (CO2) in subsurface media ? primarily saline formations, depleted or nearly depleted oil and gas...

273

Dr. Bob's Geologic Time Page  

NSDL National Science Digital Library

This is a collection of mnemonic devices to aid in learning the various periods and epochs of the geologic time scale which the author has assembled from a variety of contributors. Contributor email addresses are included. There are also mnemonic devices for Moh's hardness scale and for stratigraphic sequences from the Canyonlands-San Juan River area and the Grand Canyon.

Jorstad, Bob

2001-05-14

274

Weird Geology: The Devil's Tower  

NSDL National Science Digital Library

This page features a brief introduction to the several theories about the geological processes that formed Devil's Tower, which rises 1,267 feet above the nearby Belle Fourche River and is still considered a sacred place by some Native American Tribes. Information on climbing the tower as well as images and a cross section are provided.

Krystek, Lee; Mystery, The M.

275

Geological rhythms and cometary impacts  

NASA Technical Reports Server (NTRS)

Time series analysis reveals two dominant, long-term periodicities approximately equal to 32 and 260 million years in the known series of geological and biological upheavals during the Phanerozoic Eon. The cycles of these episodes agree in period and phase with the cycles of impact cratering on Earth, suggesting that periodic comet impacts strongly influence Earth processes.

Rampino, M. R.; Strothers, R. B.

1984-01-01

276

National Park Service Geologic Resources  

NSDL National Science Digital Library

This collection of images shows geologic features in many of the country's national parks. The collection is searchable by park name, state, year, or by the name of the photograph. Each photo is accompanied by a brief caption that provides the photographer's name, the date, and a description of the photo.

277

INTERPLANETARY CORRELATION OF GEOLOGIC TIME  

Microsoft Academic Search

Aaieroid impact has produced a significant number of medium- and large-sized craters on the earth In comparatively recent geologic time, and the rate of impact can be Interpreted to have remained fairly steady for at least the last half-billion years. By extrapolation of this rate, the lunar maria are found from the number and distribution of superimposed primary impact craters

Eugene M. Shoemaker; Robert J. Hackman; Richard E. Eggleton

278

Earth System 1: Geological Environment  

NSDL National Science Digital Library

A Geological Sciences 100 lecture available here covers the basics of folding, rock deformation, stress and strain, and strike and dip, with many related images and diagrams. The lecture was made available by the Ohio State University's School of Earth Sciences.

2008-04-25

279

Geologic exploration of solar system  

Microsoft Academic Search

The processes that must have operated on the early Earth have been deduced from evidence from ancient surfaces of the Moon and planets. In particular, such comparative studies have demonstrated that only two geologic processes have been widespread throughout the history of the solar system: impact cratering and volcanism. Impact craters have formed throughout solar system history, indeed the planets

Wood

1987-01-01

280

The whig interpretation of geology  

Microsoft Academic Search

If anyone is wondering why the editors of Biology and Philosophy are willing to publish a review of a book on the history of geology, he or she should think back to a recent 'Booknotes' (vol. 2, pp. 377-81) in which Michael Ruse fulminated against two recent contributions to this field. Ruse's critique of Martin Rudwick's Great Devonian Controversy and

Peter J. Bowler

1988-01-01

281

Amazing Altered Books  

ERIC Educational Resources Information Center

Linda Kieling, an art teacher at Rosemont Ridge Middle school in West Linn, Oregon, describes an altered book art project she introduced to her students. Alteration of books is a form of recycling that started in the eleventh century when Italian monks recycled old manuscripts written on vellum by scraping off the ink and adding new text and…

Kieling, Linda W.

2006-01-01

282

Nevada Bureau of Mines and Geology  

NSDL National Science Digital Library

The Nevada Bureau of Mines and Geology (NBMG) is a research unit of the Mackay School of Mines at the University of Nevada, Reno and is the state geological survey. Scientists at NBMG conduct research and publish reports on mineral resources and various aspects of general, environmental, and engineering geology for the state of Nevada. There are on-line publications available to download, geologic maps, K-12 educational resources for teaching about Nevada geology, and a photo and image archive of the state. Links are provided for further information about the state and general geology resources.

283

Hydrothermal alteration in the Mount Hood Area, Oregon. Bulletin  

SciTech Connect

The report describes the hydrothermal alteration of numerous outcrop samples collected in the vicinity of Mount Hood, as well as drill cuttings from 13 of the geothermal drill holes for which the authors were able to obtain sample splits. The study is also an outgrowth of a geologic and mineral survey of the Mount Hood Wilderness area in compliance with the Wilderness Act which requires that the U.S. Geological Survey and the U.S. Bureau of Mines evaluate the mineral resource potential of certain specified parcels of government-owned land.

Bargar, K.E.; Keith, T.E.C.; Beeson, M.H.

1993-01-01

284

Element speciation during nuclear glass alteration  

NASA Astrophysics Data System (ADS)

Assessing the long-term behavior of nuclear glasses implies the prediction of their long-term performance. An important controlling parameter is their evolution during interaction with water under conditions simulating geological repositories. After briefly recalling the major characteristics of the local and medium-range structure of borosilicate glasses of nuclear interest, we will present some structural features of this evolution. Specific structural tools used to determine the local structure of glass surfaces include synchrotron-radiation x-ray absorption spectroscopy with total electron yield detection. The evolution of the structure of glass surface has been determined at the Zr-, Fe-, Si- and Al-K edges and U-LIII edge. During alteration in near- or under-saturated conditions, some elements such as Fe change coordination, as other elements such as Zr only suffer structural modifications in under-saturated conditions. Uranium exhibits a modification of its speciation from an hexa-coordinated U(VI) in the borosilicate glass to an uranyl group in the gel. These structural modifications may explain the chemical dependence of the initial alteration rate and the transition to the residual regime. They also illustrate the molecular-scale origin of the processes at the origin of the glass-to-gel transformation. Eventually, they explain the provisional trapping of U by the alteration gel: the uranium retention factors in the gel depend on the alteration conditions, and thus on the nature of the resulting gel and on the trapping conditions.

Galoisy, L.; Calas, G.; Bergeron, B.; Jollivet, P.; Pelegrin, E.

2011-12-01

285

The Marine Geology Program of the US Geological Survey  

NASA Astrophysics Data System (ADS)

The U.S. Geological Survey and charged it with the responsibility for the classification of public lands and examination of the geologic structure, mineral resources and products of the national domain. The national domain for seabed resources was extended to 200 nautical miles offshore. This United States Exclusive Economic Zone (EEZ), a marine domain surrounding the continental U.S., Hawaii, and U.S. related islands, constitutes an area about one and two thirds larger than the size of the onshore area. In this vast domain lie resources of immense importance to the Nation: an estimated 35 percent of the economically recoverable oil and gas yet to be found in the United States; major resources of strategic metals like cobalt, manganese, and nickel in seafloor crusts, pavements, and modules; massive sulfide deposits actively forming today; and major concentrations of heavy minerals in nearshore sand bodies.

Edgar, N. T.

286

U.S. Geological Survey: Coastal and Marine Geology Program  

NSDL National Science Digital Library

Geologists, meteorologists, disaster specialists and others will find much to engage their attention on this website. Created by the United States Geological Survey, this site provides succinct overviews of a range of topics from the National Coastal Program Plan to El Nino, erosion, and sea-level change. Teachers should click on the drop down Content Type menu to access the Educational Materials area. Here they will find over 100 resources that highlight ocean mapping projects, core geology work, and ocean acidification. Visitors may also browse through these resources looking for movies, maps, data sets, photographs, and more. Additionally, visitors can learn about the program's field centers, located in St. Petersburg, Woods Hole, and Menlo Park.

2012-02-28

287

The geology of the terrestrial planets  

NASA Technical Reports Server (NTRS)

The geologic history of the terrestrial planets is outlined in light of recent exploration and the revolution in geologic thinking. Among the topics considered are planet formation; planetary craters, basins, and general surface characteristics; tectonics; planetary atmospheres; and volcanism.

Carr, M. H. (editor); Saunders, R. S.; Strom, R. G.; Wilhelms, D. E.

1984-01-01

288

Constraints on the geologic history of “Home Plate” materials provided by clast morphology and texture  

Microsoft Academic Search

We quantified and classified the size, shape, roundness, and texture of 333 loose surface particles (clasts) along the Spirit rover traverse from Martian solar days 750 to 1889. These data provided clues to origin, transport mechanisms, association with geologic units, and other alteration processes. Clasts average 15 mm in size and 0.73 sphericity, and display a low degree of roundness;

R. A. Yingst; L. Crumpler; W. H. Farrand; R. Li; P. de Souza

2010-01-01

289

Geology Fieldnotes: Timpanogos National Monument, Utah  

NSDL National Science Digital Library

Timpanogos Cave National Monument, in the Wasatch Mountains, features spectacularly decorated caverns, each of which has unique colors and formations. Features of the site include park geology information, maps, photographs of cave formations, related links, and visitor information. The park geology section discusses the caves' geologic history, structural geology, and details the discovery of the Hansen and Middle Caves (by Martin, George, and Wayne Hansen) and the Timpanogos Cave (by Veral Manwill).

290

Planetary geology in the 1980s  

NASA Technical Reports Server (NTRS)

The geologic aspects of solar system studies are defined and the goals of planetary geology are discussed. Planetary geology is the study of the origin, evolution, and distribution of matter condensed in the form of planets, satellites, asteroids, and comets. It is a multidisciplinary effort involving investigators with backgrounds in geology, chemistry, physics, astronomy, geodesy, cartography, and other disciplines concerned with the solid planets. The report is primarily restricted to the kinds of experiments and observations made through unmanned missions.

Veverka, J.

1984-01-01

291

Geology Fieldnotes: Oregon Caves National Monument  

NSDL National Science Digital Library

Oregon Caves National Monument is an active marble cave created by natural forces over hundreds of thousands of years in one of the world's most diverse geologic realms. Features of the site include park geology information, maps, photographs, related links, and visitor information. The park geology section discusses the cave's development and geologic history, its formations, and its development as a National Monument. The maps section includes an area map of the National Monument.

292

Geology Fieldnotes: Great Basin National Park, Nevada  

NSDL National Science Digital Library

This Great Basin National Park site contains park geology information, park maps, visitor information, and teacher features (educational resources and links for teaching geology using National Park examples). The park geology section discusses the region's biogeography, glacial history, and the Lehman Caves. A park map and a features/relief map of the Great Basin National Park are included.

293

Medical geology: a globally emerging discipline  

Microsoft Academic Search

Medical Geology, the study of the impacts of geologic materials and processes on animal and human health, is a dynamic emerging discipline bringing together the geoscience, biomedical, and public health communities to solve a wide range of environmental health problems. Among the Medical Geology described in this review are examples of both deficiency and toxicity of trace element exposure. Goiter

Joseph E. Bunnell; Robert B. Finkelman; Jose A. Centeno; O. Selinus

2007-01-01

294

Tour of Park Geology: Human Use Sites  

NSDL National Science Digital Library

This National Park Service (NPS) site provides links to geolgy field notes about National Parks, National Monuments, and National Recreation Areas having to do with geology and human use (such as mining). Information includes geology, photographs, multimedia tools, park maps, visitor information, geologic research, and additional links. Parks covered include Klondike Gold Rush National Historic Park, Alibates Flint Quarries National Monument, and more.

295

The Geologic Story of the Ocoee River  

NSDL National Science Digital Library

The United States Geological Survey (USGS) highlights the geology of the Ocoee River, in the scenic Cherokee National Forest of southeastern Tennessee. This report covers the geologic history of the area, from 750 million years ago (Precambrian) to the present. Uses of the river, from dams to mining, are also discussed.

296

Geology Fieldnotes: Cape Krusenstern National Monument, Alaska  

NSDL National Science Digital Library

This site provides geologic information, maps, and visitor information for Cape Krusenstern National Monument. The geologic discussion covers the setting, history, bedrock geology, and glacial history of the monument. There is also a discussion of the area's major soil types and occurrence of permafrost. Other materials include links to related websites and general information on the monument's educational and interpretive programs.

297

U.S. Geological Survey Geologic Carbon Sequestration Assessment  

NASA Astrophysics Data System (ADS)

The Energy Independence and Security Act of 2007 authorized the U.S. Geological Survey (USGS) to conduct a national assessment of potential geological storage resources for carbon dioxide (CO2) in consultation with the U.S. Department of Energy (DOE), the U.S. Environmental Protection Agency (EPA) and State geological surveys. To conduct the assessment, the USGS developed a probability-based assessment methodology that was extensively reviewed by experts from industry, government and university organizations (Brennan et al., 2010, http://pubs.usgs.gov/of/2010/1127). The methodology is intended to be used at regional to sub-basinal scales and it identifies storage assessment units (SAUs) that are based on two depth categories below the surface (1) 3,000 to 13,000 ft (914 to 3,962 m), and (2) 13,000 ft (3,962 m) and greater. In the first category, the 3,000 ft (914 m) minimum depth of the storage reservoir ensures that CO2 is in a supercritical state to minimize the storage volume. The depth of 13,000 ft (3,962 m) represents maximum depths that are accessible with average injection pressures. The second category represents areas where a reservoir formation has potential storage at depths below 13,000 ft (3,962 m), although they are not accessible with average injection pressures; these are assessed as a separate SAU. SAUs are restricted to formation intervals that contain saline waters (total dissolved solids greater than 10,000 parts per million) to prevent contamination of protected ground water. Carbon dioxide sequestration capacity is estimated for buoyant and residual storage traps within the basins. For buoyant traps, CO2 is held in place in porous formations by top and lateral seals. For residual traps, CO2 is contained in porous formations as individual droplets held within pores by capillary forces. Preliminary geologic models have been developed to estimate CO2 storage capacity in approximately 40 major sedimentary basins within the United States. More than 200 SAUs have been identified within these basins. The results of the assessment are estimates of the technically accessible storage resources based on present-day geological and engineering technology related to CO2 injection into geologic formations; therefore the assessment is not of total in-place resources. Summary geologic descriptions of the evaluated basins and SAUs will be prepared, along with the national assessment results. During the coming year, these results will be released as USGS publications available from http://energy.usgs.gov. In support of these assessment activities, CO2 sequestration related research science is being conducted by members of the project. Results of our research will contribute to current and future CO2 storage assessments conducted by the USGS and other organizations. Research topics include: (a) geochemistry of CO2 interactions with subsurface environments; (b) subsurface petrophysical rock properties in relation to CO2 injection; (c) enhanced oil recovery and the potential for CO2 storage; (d) storage of CO2 in unconventional reservoirs (coal, shale, and basalt); (e) statistical aggregation of assessment results; and (f) potential risks of induced seismicity.

Warwick, P. D.; Blondes, M. S.; Brennan, S.; Corum, M.; Merrill, M. D.

2012-12-01

298

Geological and inorganic materials. [Review  

SciTech Connect

This review discusses publications describing methods for analysis of geological and inorganic materials during the period November 1982 through November 1984. The topical boundaries of the inorganic and geological materials are somewhat diffuse since closely related topics are reviewed in both the fundamental and application reviews. Articles of particular interest may be found in the reviews of air pollution, ferrous analysis, fuels, surface characterization, and water analysis in the application reviews and many of the fundamental reviews especially sampling, emission spectrometry, atomic adsorption and flame emission spectrophotometry, mass spectrometry, x-ray spectrometry, and surface analysis. The citations of this review may well, by necessity, include some of those listed in other reviews, but for the most part they have been selected from the many thousands available to give the reader an overview of recent advances in each specialty reviewed together with mentions of particularly interesting specific or specialized contributions. 212 references.

Moore, C.B.; Canepa, J.A.

1985-04-01

299

Complex Geologic History of Triton  

NASA Technical Reports Server (NTRS)

Part of the complex geologic history of icy Triton, Neptune's largest satellite, is shown in this Voyager 2 photo, which has a resolution of 900 meters (2,700 feet) per picture element. The photo was received as part of a Triton-mapping sequence between 3:30 and 5:30 a.m. (PDT). This view is about 500 kilometers (300 miles) across. It encompasses two depressions, possibly old impact basins, that have been extensively modified by flooding, melting, faulting, and collapse. Several episodes of filling and partial removal of material appear to have occurred. The rough area in the middle of the bottom depression probably marks the most recent eruption of material. Only a few impact craters dot the area, which shows the dominance of internally driven geologic processes on Triton.

JPL manages the Voyager project for NASA's Office of Space Science.

1989-01-01

300

Geologic and Navajo Time Line  

NSDL National Science Digital Library

This lab serves to introduce students to geologic time and serves as an outline for the course through the semester. Students use a tape register and must mark out the corresponding length of each Geologic Era and Eon towards the beginning of the course. Above Western time line Navajo students construct their own time line correlating events as best as possible. As the course progresses starting from 4.6bya each week they must draw major events that occur marking correct subdivisions of time and ages ago. As fossil life gets more complex such as beginning in the Paleozoic students are must take different categories of fossils or different periods so all are doing different things but working together. (Similarly the Navajo time line builds. This time line is taped around the room---and I would have liked to paint the two time lines along the corridor of the building but Maintenance axed it.

Mayer, Margaret

301

The Concise Geologic Time Scale  

NASA Astrophysics Data System (ADS)

This concise handbook presents a summary of Earth's history over the past 4.5 billion years as well as a brief overview of contemporaneous events on the Moon, Mars and Venus. The authors have been at the forefront of chronostratigraphic research and initiatives to create an international geologic time scale for many years, and the charts in this book present the most up to date, international standard, as ratified by the International Commission on Stratigraphy and the International Union of Geological Sciences. This book is an essential reference for all geoscientists, including researchers, students, and petroleum and mining professionals. The presentation is non-technical and illustrated with numerous colour charts, maps and photographs. The book also includes a detachable laminated card of the complete time scale for use as a handy reference in the office, laboratory or field.

Ogg, James G.; Ogg, Gabi; Gradstein, Felix M.

302

Shock compression of geological materials  

NASA Astrophysics Data System (ADS)

Understanding the shock compression of geological materials is important for many applications, and is particularly important to the mining industry. During blast mining the response to shock loading determines the wave propagation speed and resulting fragmentation of the rock. The present work has studied the Hugoniot of two geological materials; Lake Quarry Granite and Gosford Sandstone. For samples of these materials, the composition was characterised in detail. The Hugoniot of Lake Quarry Granite was predicted from this information as the material is fully dense and was found to be in good agreement with the measured Hugoniot. Gosford Sandstone is porous and undergoes compaction during shock loading. Such behaviour is similar to other granular material and we show how it can be described using a P-a compaction model.

Kirk, S.; Braithwaite, C.; Williamson, D.; Jardine, A.

2014-05-01

303

The geology of 433 Eros  

Microsoft Academic Search

The global high-resolution imaging of asteroid 433 Eros by the Near-Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft has made it possible to develop the first comprehensive picture of the geology of a small S-type asteroid. Eros displays a variety of surface features, and evidence of a substantial regolith. Large scale facets, grooves, and ridges indicate the presence of at least one

M. S. Robinson; P. C. Thomas; J. Veverka; S. L. Murchie; B. B. Wilcox

2002-01-01

304

Geological Time Capsule Part I  

NSDL National Science Digital Library

This brief review of Earth history starts with the Archeozoic Period and goes through the Devonian Period. It explains time divisions and that the basic unit of geologic time is the period, which comprises two or more epochs, and that an era consists of two or more periods. The site goes on to explain what was happening in regard to plate tectonics and organic evolution in each of the periods through the Devonian Period.

Oberrecht, Kenn

2007-04-08

305

Geology of Badlands National Park  

NSDL National Science Digital Library

This page is an introduction to the 75 million years of accumulation and intermittent periods of erosion that has resulted in the Badlands National Park. The history of the Oglicene beds of the Park, one of the world's richest vertebrate fossil sites, is also described. A downloadable PDF that describes the erosion that is responsible for the geology of the Park in more detail is linked to the site.

National Park Service (NPS)

306

Perkins Geology Museum Digital Archive  

NSDL National Science Digital Library

This online database contains thousands of digital images from the collections of the University of Vermont's Perkins Geology Museum. The collection emphasizes material from Vermont, but it also includes rock and mineral specimens, maps, slides, thin sections, and photographs from around the world. It can be browsed by type (rocks, minerals, fossils, or thin sections) or searched by keyword and locality. Each image is accompanied by brief metadata, including title, file name and catalog number, image resolution, and locality (where available).

307

U. S. Geological Survey Library  

NSDL National Science Digital Library

The United States Geological Survey (USGS) Library is the largest earth science library in the world. The library serves the research needs of USGS scientists throughout the nation and provides information to other organizations and individuals in the areas of geology, hydrology, cartography, biology, and related fields. USGS libraries are located in Reston, Virginia, Denver, Colorado, Menlo Park, California, and Flagstaff, Arizona. Some of the library holdings are available on-line, while others can be purchased from USGS, ordered via an interlibrary loan, or attained from one of the four library locations directly. The library home page provides links to search engines for USGS publications, photographs, maps, etc. Users can search various databases to find what they need. These databases include: the Geographic Names Information System database, the Minerals Information Collection, the National Geologic Map Database, and a database of purchased journals held by the library. Users can also search the library's catalog, and can post questions to a librarian via the Ask a Librarian link.

308

Dione's spectral and geological properties  

USGS Publications Warehouse

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.

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

309

Geologic mapping using thermal images  

NASA Technical Reports Server (NTRS)

Thermal radiance data from the Heat Capacity Mapping Mission (HCMM) satellite has been used to measure surface reflectance data and to provide additional material composition information through remote sensing. The primary goal was to investigate the utility of HCMM data for geologic applications. Three techniques were used for displaying and combining thermal and visible near infrared (VNIR) data for two desert areas in southern California (Trona and Pisgah): color additive composites (CAC) for day and night IR and day VNIR, principal components, and calculation of thermal inertia images. The HCMM thermal data were more effective than Landsat data in producing separation of compositionally different areas including volcanic and intrusive rocks. The satellite CAC data produced an image for a 1 x 2 degree area, and the color picture was enlarged to a scale of 1:250,000. Playa composition, moisture content, presence of standing water, and vegetation cover were displayed in a variety of colors according to physical characteristics. Areas such as sand dunes were not distinguishable because of the coarse 500-mm HCMM resolution. HCMM thermal data have shown a new dimension to geologic remote sensing, and future satellite missions should allow the continued development of the thermal infrared data for geology.

Abrams, M. J.; Kahle, A. B.; Palluconi, F. D.; Schieldge, J. P.

1984-01-01

310

Importance of geology to fisheries management: Examples from the northeastern Gulf of Mexico  

USGS Publications Warehouse

Seafloor mapping of shelf-edge habitats in the northeastern Gulf of Mexico demonstrates how sidescan-sonar imagery, seismic-reflection profiling, video data, geologic mapping, sediment sampling, and understanding the regional geologic history can enhance, support, and guide traditional fisheries research and management. New data from the Madison Swanson and Steamboat Lumps Marine Reserves reveal complex benthic habitats consisting of high-relief calcareous pinnacles, low-relief karstic hardbottom, rocky outcrops several kilometers in length, and variable thickness of fine-grained and apparently mobile coarse-grained sediments. Our data also show that certain fish alter the landscape by clearing sediment from hardbottom areas (e.g., red grouper Epinephelus morio) and by burrowing extensively in fine-grained sediment (e.g., tilefish Lopholatilus chamaeleonticeps). The seafloor imagery and geologic maps show that (a) sea level fluctuations played a dominant role in the development of the present-day regional geology, and (b) habitats (and benthic communities) are tied closely to geologic character. Understanding the geologic setting allowed for efficient and representative sampling of the biology. The geologic data can be used to set meaningful boundaries for fishery reserves and to help predict habitats in areas that are not well mapped. This interdisciplinary work added value to traditional research disciplines by providing management with integrated tools to make better decisions. ?? Copyright by the American Fisheries Society 2003.

Scanlon, K. M.; Koenig, C. C.; Coleman, F. C.; Miller, M.

2003-01-01

311

Geologic Map of Loudoun County, Virginia  

USGS Publications Warehouse

Introduction The geology of Loudoun County, Va., was mapped from 1988 through 1991 under a cooperative agreement between the U.S. Geological Survey (USGS) and the Loudoun County Office of Mapping and Geographic Information. This geologic map was compiled in 1993 from a series of detailed published and unpublished field investigations at scales of 1:12,000 and 1:24,000. Some of these same data were compiled as a digital geologic map at 1:100,000 scale (Burton and others, 1992a) and were the basis for a cost-benefit analysis of the societal value of geologic maps (Bernknopf and others, 1993).

Southworth, Scott; Burton, William C.; Schindler, J. Stephen; Froelich, Albert J.

2006-01-01

312

Mapping hydrothermal alteration in Yellowstone National Park using magnetic methods  

NASA Astrophysics Data System (ADS)

Yellowstone National Park (YNP) hosts a very large hydrothermal system with over 10,000 thermal features. Hydrothermal alteration in YNP has been mapped with field observations and remote-sensing imagery, but these methods can only detect alteration at the ground surface. Magnetic surveys are useful for detecting buried hydrothermal alteration as demonstrated by a recent high-resolution aeromagnetic survey in YNP (Finn and Morgan, J. Volcanol. Geotherm. Res., 115, 207-231, 2002). Results of this survey show that magnetic lows extend over and beyond areas of hydrothermal activity, suggesting large volumes of demagnetized rocks due to hydrothermal alteration of the volcanic substratum. Although results of this aeromagnetic survey were of relatively high resolution, they were insufficient for more detailed mapping of alteration. In September 2008, we collected ground magnetic profiles in four hydrothermal areas within YNP (Norris Geyser Basin, Lower Geyser Basin, Lone Star Geyser, and Smoke Jumper Hot-springs). These measurements were performed using a cesium-vapor magnetometer along several 4-5 km long transects crossing hydrothermal features. In addition, we collected gravity data to characterize the subsurface geologic structures. We also performed magnetic susceptibility, magnetic remanence and density measurements on rock samples collected in the field and from drill cores collected in 1967-1968 to characterize physical properties of fresh and altered geologic units. Ground magnetic profiles acquired over unaltered areas display large-amplitude short-wavelength anomalies due to the existence of many shallow contrasts of magnetization in the volcanic substratum. In contrast, the short-wavelength anomaly signal is of very low amplitude in altered areas supporting demagnetization of the shallow volcanic basement. These new geophysical and physical property data are being used to map the distribution of rock density and magnetic properties, model the subsurface geometry of altered areas and investigate the relationship of these areas with structures such as contacts, faults, and fractures that may facilitate the circulation of hydrothermal fluids.

Bouligand, C.; Glen, J. M.

2010-12-01

313

Application of plurigaussian simulation to delineate the layout of alteration domains in Sungun copper deposit  

NASA Astrophysics Data System (ADS)

An accurate estimation of mineral grades in ore deposits with heterogeneous spatial variations requires defining geological domains that differentiate the types of mineralogy, alteration and lithology. Deterministic models define the layout of the domains based on the interpretation of the drill holes and do not take into account the uncertainty in areas with fewer data. Plurigaussian simulation (PGS) can be an alternative to generate multiple numerical models of the ore body, with the aim of assessing the uncertainty in the domain boundaries and improving the geological controls in the characterization of quantitative attributes. This study addresses the application of PGS to Sungun porphyry copper deposit (Iran), in order to simulate the layout of four hypogene alteration zones: potassic, phyllic, propylitic and argillic. The aim of this study is to construct numerical models in which the alteration structures reflect the evolution observed in the geology.

Talebi, Hassan; Asghari, Omid; Emery, Xavier

2013-12-01

314

Val Verde basin study integrates gravity, magnetic, geologic data  

SciTech Connect

In early 1990, a study integrating gravity, magnetic, surface geology and subsurface geology was completed of a 1,250 mile sector of the Val Verde basin. The study's objective was to develop a perspective of the region's structural framework and priority prospect leads for site-specific evaluation by the more definitive yet much more expensive geochemical and seismic methods. To achieve these objectives, two main principles were applied: (1) that the structural disturbance of near-surface sedimentary formations and/or the geochemical alteration products caused by the microseepage of hydrocarbons give rise to geophysically measurable lateral changes in formation density, magnetization, conductivity, and so forth; (2) that certain survey methods are suited for reconnaissance while others are best utilized in the detailed definition phase of an exploration program and that the most cost-effective program is one in which several methods appropriate to the geologic setting are systematically applied in their ascending order of cost and definition. In 1993, a significant wildcat discovery, the Tom Brown-Conoco 1 ACU Strawn Field, in Terrell County, Tex., was drilled within the boundary of one of the study's prospect leads. This article presents the information potential of each of the methods applied and the benefits of weighing the information from each type of data against that of the others to better define the configuration and priority of each prospect lead.

Land, J.P. (J.P. Land Associates Inc., Houston, TX (United States))

1994-10-24

315

Chromite alteration processes within Vourinos ophiolite  

NASA Astrophysics Data System (ADS)

The renewed interest in chromite ore deposits is directly related to the increase in Cr price ruled by international market trends. Chromite, an accessory mineral in peridotites, is considered to be a petrogenetic indicator because its composition reflects the degree of partial melting that the mantle experienced while producing the chromium spinel-bearing rock (Burkhard in Geochim Cosmochim Acta 57:1297-1306, 1993). However, the understanding of chromite alteration and metamorphic modification is still controversial (e.g. Evans and Frost in Geochim Cosmochim Acta 39:959-972, 1975; Burkhard in Geochim Cosmochim Acta 57:1297-1306, 1993; Oze et al. in Am J Sci 304:67-101, 2004). Metamorphic alteration leads to major changes in chromite chemistry and to the growth of secondary phases such as ferritchromite and chlorite. In this study, we investigate the Vourinos complex chromitites (from the mines of Rizo, Aetoraches, Xerolivado and Potamia) with respect to textural and chemical analyses in order to highlight the most important trend of alteration related to chromite transformation. The present study has been partially funded by the Aliakmon project in collaboration between the Public Power Corporation of Greece and Institute of Geology and Mineral Exploration of Kozani.

Grieco, Giovanni; Merlini, Anna

2012-09-01

316

Geologic Sequestration Studies with Hawaiian Picrites  

NASA Astrophysics Data System (ADS)

Capturing and storing anthropogenic carbon dioxide in deep geologic formations is a potential CO2 mitigation solution being studied to reduce adverse effects of increasing greenhouse gas concentrations on the global climate. Basalt formations, widespread globally, are currently being considered as a long term storage option. Because combustion gas streams often contain impurities, it is also important to consider contaminants (e.g., SO2, N2, and O2) that could be co-injected with CO2. Injecting to depths greater than 800 m, these CO2 gas mixtures will reside as water-wet supercritical fluids in contact with the basalt reservoir rocks. Here we examine reaction products resulting from exposing Hawaiian picrite basalts to water equilibrated with scCO2, water bearing scCO2, and mixtures containing gaseous sulfur compounds. Hawaiian basalts in this study were fresh, vesicular, and olivine(fo68)-rich (20+vol%). Basalts, crushed or in large pieces, were exposed to wet supercritical fluid and aqueous dissolved gases for 80 to 550 days at 100 bar and 50°-100°C. Post-reacted basalt in the pure scCO2 system showed the least amount of reactivity. Carbonate precipitates formed discrete circular coatings on the olivine grain surfaces after 550 days of exposure to the aqueous dissolved CO2. However, the olivine surface was significantly altered in just 80 days after exposure to wet scCO2 containing 1% SO2. The most reactive basalt components were olivine grains, with surfaces dominated by cracks and precipitates of Mg-S compounds (Fig.1). Chemistry determined by SEM-EDS indicated the cracked surface was depleted in Mg and rich in Si. Minor amounts of sulfur were detected in this leached layer as well. Exposed olivine interiors were found to have the original olivine chemistry. Surface precipitates associated with the olivine crystals include hexahydrite (MgSO4?6H2O), magnesium thiosulfate hydrate (MgS2O3?6H2O), along with three different hydrated sulfite phases. These types of experiments illustrate the potential basalt formations hold for long term storage of CO2 and the importance of understanding supercritical phase chemical reactions involved in geologic carbon sequestration. Expanding on this work, research in collaboration with Yale scientists on the CO2 storage potential of a wide range of rocktypes will commence in Fall, 2010. Figure 1. SEM microphotograph of reacted olivine surface (HW496) after 85 days exposure to wet scCO2 containing ~1% SO2 (10 MPa and 50°C).

Johnson, K. T.; McGrail, B. P.; Schaef, H. T.

2010-12-01

317

A Geologic Time Scale 2004  

NASA Astrophysics Data System (ADS)

This may be the most straightforward book review imaginable to write. Just buy this book and use it! You will not regret it.Verlyn Klinkenborg's 23 August 2005 editorial in the New York Times (“Grasping the depth of time as a first step in understanding evolution”) serves as a most timely way begin a review of A Geologic Time Scale 2004 (GTS2004). Klinkenborg writes, “One of the most powerful limits to the human imagination is our inability to grasp, in a truly intuitive way the depths of terrestrial and cosmological time.”

Geissman, John W.

318

Science Sampler: School yard geology  

NSDL National Science Digital Library

"Can we break rocks again today?" This statement is typical of the excitement students show for identifying rock types after they apply their rock identification knowledge to the geology in the school yard. Many school yards, although bulldozed during construction, still exhibit telling outcrops of the underlying bedrock. Armed with a few materials, you can discover what is just outside your door while modeling the joy of doing science. This activity fits into the curriculum after the rock cycle and igneous, sedimentary, and metamorphic rock identification labs.

Hagberg, Beverly; Sterling, Donna R.

2008-12-01

319

Geological rhythms and cometary impacts  

NASA Technical Reports Server (NTRS)

Time-series analysis reveals two dominant, stable long-term periodicities approximately equal to 33 + or - 3 and 260 + or - 25 million years in the known series of geological and biological upheavals during the Phanerozoic Eon. Because the cycles of these episodes agree in period and phase with the cycles of impact cratering on earth, these results suggest that periodic comet impacts strongly influence global tectonism and biological evolution. These two periodicities could arise from interactions of the solar system with interstellar clouds as the solar system moves cyclically through the Galaxy.

Rampino, M. R.; Stothers, R. B.

1984-01-01

320

Connecting Soils and Glacial Geology  

NSDL National Science Digital Library

The goal of this activity is to provide students an opportunity to connect soil science to surficial geology by using a Soil Surveys. By the end of the activity, students should be able to use a Soil Survey to identify and interpret landforms and surficial features. This activity can be adapted to variety of process (ex. eolian deposits, glacial deposits, bedrock weathering, etc.). County-level soil surveys are available in both paper and online formats for the majority of the United States. Designed for a geomorphology course Has minimal/no quantitative component

Dolliver, Holly

321

Ore metals through geologic history.  

PubMed

The ores of chromite, nickel, copper, and zinc show a wide distribution over geologic time, but those of iron, titanium, lead, uranium, gold, silver, molybdenum, tungsten, and tin are more restricted. Many of the limitations to specific time intervals are probably imposed by the evolving tectonic history of Earth interacting with the effects of the biomass on the evolution of the earth's s surface chemistry. Photosynthetic generation of free oxygen and "carbon" contributes significantlly to the diversity of redox potentials in both sedimentary and igneous-related processes of ore formation, influencing the selection of metals at the source, during transport, and at the site of ore deposition. PMID:17777763

Meyer, C

1985-03-22

322

Efficient Geological Modelling of Large AEM Surveys  

NASA Astrophysics Data System (ADS)

Combining geological expert knowledge with geophysical observations into a final 3D geological model is, in most cases, not a straight forward process. It typically involves many types of data and requires both an understanding of the data and the geological target. When dealing with very large areas, such as modelling of large AEM surveys, the manual task for the geologist to correctly evaluate and properly utilise all the data available in the survey area, becomes overwhelming. In the ERGO project (Efficient High-Resolution Geological Modelling) we address these issues and propose a new modelling methodology enabling fast and consistent modelling of very large areas. The vision of the project is to build a user friendly expert system that enables the combination of very large amounts of geological and geophysical data with geological expert knowledge. This is done in an "auto-pilot" type functionality, named Smart Interpretation, designed to aid the geologist in the interpretation process. The core of the expert system is a statistical model that describes the relation between data and geological interpretation made by a geological expert. This facilitates fast and consistent modelling of very large areas. It will enable the construction of models with high resolution as the system will "learn" the geology of an area directly from interpretations made by a geological expert, and instantly apply it to all hard data in the survey area, ensuring the utilisation of all the data available in the geological model. Another feature is that the statistical model the system creates for one area can be used in another area with similar data and geology. This feature can be useful as an aid to an untrained geologist to build a geological model, guided by the experienced geologist way of interpretation, as quantified by the expert system in the core statistical model. In this project presentation we provide some examples of the problems we are aiming to address in the project, and show some preliminary results.

Bach, Torben; Martlev Pallesen, Tom; Jørgensen, Flemming; Lundh Gulbrandsen, Mats; Mejer Hansen, Thomas

2014-05-01

323

Geology and mineral deposits of the Jabal ash Shumta quadrangle, Kingdom of Saudi Arabia  

USGS Publications Warehouse

Rocks, structures, and mineral deposits which are the result of both the older Halaban petro-tectonic cycle and the younker Najd Wrench Fault deformation are present in the Ash Shumta area. Northward-trending belts of granitic rocks and folded, layered metavolcanic and metasedimentary rocks of the Halaban Formation which they intrude represent the effects of the Halaban cycle. These older rocks are everywhere transected and deformed by northwestward- and northeastward-striking fractures and strike-slip faults and by eastward-striking fractures and fracture-controlled silicic dikes which belong to the Najd Wrench Fault deformation. Several kinds of epigenetic mineral deposits of hydrothermal origin are present throughout the Ash Shumta area. All occur in or ape closely associated with structures of the Najd Wrench Fault deformation. The mineralization which produced the deposits is thought to have taken place during the period of deformation which produced the Najd Wrench Fault structures. The hydrothermal deposits include many metalliferous quartz veins most of which occur in three mineralized areas: two major areas at Jabal Ash Shumta and Jabal El Khom in the northern half of the quadrangle and a minor area along Wadj al Boharah in the southeastern part of the quadrangle. The metalliferous lodes possess the only economic potential in the area of the Jabal Ash Shumta quadrangle. These lodes consist mainly of gold and base metal-bearing quartz veins, some of which were mined for gold in ancient times. The mineralized area at Jabal Ash Shumta has the best of these veins. Higher temperature veins with wolframite as a major constituent and beryl as a minor one occur in a granite cupola in the eastern part of the El Khom area. These veins have altered, gneissen-like wall rocks. Although the grade of the veins is low at the surface, the made could increase at depth. The tungsten-bearing veins and El Khom area possess the greatest economic promise in the Jabal Ash Shumta quadrangle. They deserve detailed surface investigation followed if needed by exploration at depth.

Hummel, C. L.; Ankary, Abdullah O.

1972-01-01

324

Medical Geology - Special Initiative of the International Union of Geological Scientists  

NSDL National Science Digital Library

This is the official home page of the International Working Group on Medical Geology, a special initiative of the International Union of Geological Sciences. The group was organized to improve communication among the various disciplines concerned with diseases caused by geological factors, as well as promote the development of educational materials, literature, and further research and programs that address the issue of medical geology. This site provides links to information about current research, meetings, and other activities of the International Medical Geology Association; books, reports, brochures and other literature for sale or download; membership opportunities and discussion groups; outreach and education; a glossary of medical, geological, chemical, and biological terms, and much more.

Geology, International W.

325

Biologically Enhanced Geologic Carbon Sequestration  

NASA Astrophysics Data System (ADS)

There are four trapping mechanisms proposed to play significant roles in the deep geologic sequestration of CO2: i) formation trapping, ii) capillary trapping, iii) solubility trapping, and iv) mineral trapping. Our research has shown that microbial biofilms are capable of enhancing formation trapping, solubility trapping, and mineral trapping under conditions found in brine aquifers targeted for geologic carbon sequestration. We have demonstrated that engineered microbial biofilms are capable of reducing the permeability of porous media (including sandstone cores) at pressures and temperatures, which would be found in the presence of supercritical CO2. The formed biofilms have been demonstrated by us to be resistant to supercritical CO2 exposure. Microbial biofilms have been shown by us to precipitate CO2 in the form of calcium carbonate (CaCO3), which resists dissolution by brine and supercritical CO2. We observed that microbial activity in brine can increase rate and extent of CO2 solubilization in brine. This presentation will summarize our activities, which are part of U.S. DOE sponsored research at Montana State University, focusing on the development of biologically-based concepts for enhanced carbon sequestration.

Gerlach, Robin; Mitchell, Andrew C.; Spangler, Lee H.; Cunningham, Al B.

2010-05-01

326

Geology of the Uranian satellites  

NASA Astrophysics Data System (ADS)

A geological analysis of six of the Uranus satellites observed in detail by Voyager 2 is presented. All of the satellites except the smallest, Puck, show evidence of cryovolcanic resurfacing: global on the largest four satellites, local in the spectacular coronae on Miranda. The cryovolcanic materials exhibit a range of albedos and morphologies, which are interpreted to reflect a variety of compositions and conditions of eruption at least as complex as those which occur on earth. Eruptions are predominantly large fissure flows that produce extensive flood deposits. Possible evidence of small circular vents and cryoclastic volcanic activity is seen on Miranda and Ariel. All of the satellites except Puck also have extensive sets of grabens and riftlike canyons that show remarkable similarity of pattern: intersection sets trending roughly NW-SW and NE-SW in the low latitudes grading into E-W trends near the poles. As a group, the Uranian satellites are somewhat more active geologically than similarly sized Saturnian satellites.

Croft, S. K.; Soderblom, L. A.

327

Fat Alterations in Injury.  

National Technical Information Service (NTIS)

The influence of injury on fat metabolism is a dramatic example of how surgeons had depended upon the wisdom of the body to regulate whatever alterations are needed without causing abnormal concentration of lipid material in either the plasma or in variou...

J. M. Kinney

1983-01-01

328

Altered retmoic acid receptors  

Microsoft Academic Search

Structurally and functionally altered retinoic acid receptors have been associated with rare human neoplasms: acute promyelocytic leuke- mia and hepatoceilular carcinoma. Whereas the ret- inoic acid receptor 13 (RAR13) rearrangement in hepatocellular carcinoma is unique, in acute promyelocytic leukemia (APL), RARU fusion to the promyelocytic leukemia (PML) gene by the t(15;17) translocation is a general feature of the disease. APL

CNRS UPR; Service de Biochimie

329

Alteration Order #11  

Microsoft Academic Search

The purpose of the alteration was to control sneak circuits which cause premature arming of MC-76 components which cause premature arming of MC-76 components and to provide higher current carrying capacity through the fusing circuit of the MC-36.

Biskner

1952-01-01

330

Immunization alters body odor.  

PubMed

Infections have been shown to alter body odor. Because immune activation accompanies both infection and immunization, we tested the hypothesis that classical immunization might similarly result in the alteration of body odors detectable by trained biosensor mice. Using a Y-maze, we trained biosensor mice to distinguish between urine odors from rabies-vaccinated (RV) and unvaccinated control mice. RV-trained mice generalized this training to mice immunized with the equine West Nile virus (WNV) vaccine compared with urine of corresponding controls. These results suggest that there are similarities between body odors of mice immunized with these two vaccines. This conclusion was reinforced when mice could not be trained to directly discriminate between urine odors of RV- versus WNV-treated mice. Next, we trained biosensor mice to discriminate the urine odors of mice treated with lipopolysaccharide (LPS; a general elicitor of innate immunological responses) from the urine of control mice. These LPS-trained biosensors could distinguish between the odors of LPS-treated mouse urine and RV-treated mouse urine. Finally, biosensor mice trained to distinguish between the odors of RV-treated mouse urine and control mouse urine did not generalize this training to discriminate between the odors of LPS-treated mouse urine and control mouse urine. From these experiments, we conclude that: (1) immunization alters urine odor in similar ways for RV and WNV immunizations; and (2) immune activation with LPS also alters urine odor but in ways different from those of RV and WNV. PMID:24524972

Kimball, Bruce A; Opiekun, Maryanne; Yamazaki, Kunio; Beauchamp, Gary K

2014-04-10

331

The National Park Service: Park Geology  

NSDL National Science Digital Library

A National Park Service (NPS) site primarily composed of three main sections corresponding to the following program areas within the Geologic Resources Division (GRD): Disturbed Lands Restoration and Abandoned Mineral Lands (AML), Mineral Management Programs, and Geology and Soils Programs. Of these, the first two consist principally of textual resources pertaining to Park System procedures, policies, and regulations - as well as reports on example restoration projects with a focus on stream corridor restoration, bioengineering, riparian management, and revegetation. Perhaps of most interest to educators will be the third main program area, the Geology and Soils Programs section. Here are included textual resources pertaining to NPS-GRD programs on cave and karst formations, coastal and shoreline geology, paleontology, soils (e.g., soil biology and soil surveying), geological indicators (geoindicators), and stratigraphy. Lastly, a searchable photographic collection and geologic glossary are available.

332

Geologic Provinces of the United States  

NSDL National Science Digital Library

This site provides all information, instructions, downloadable materials, and links to online materials for an exercise developed for use in a Geology of the National Parks course. Using the provided maps, groups of 3 to 6 students are asked to identify between 8 and 12 geologic provinces based on topography, the age of rocks, and the rock types. As a result of this exercise, students will become familiar and comfortable with reading maps and legends, learn basic rock types and how geologic time is divided, define geologic provinces that will form an outline for learning the geology of the U.S., and be able to discuss the maps they create based on what they've learned. This exercise is intended for one of the first class meetings of the quarter or semester and ideally students will approach this exercise without much or any prior knowledge of the geology of the United States.

Leech, Mary

333

Genetic alterations in breast cancer  

Microsoft Academic Search

The development of neoplasms is the result of the accumulation of genetic alterations. In breast cancer, large efforts have been dedicated to unravel these genetic alterations and to find associations between specific genetic alterations and the clinical and pathological characteristics of the tumour. There has been rapid advancement of the available techniques to identify new genetic alterations; technical advancement will

M. J. van de Vijver

2000-01-01

334

Links between carbonate alteration in orogenic gold deposits and alkaline magmatism  

NASA Astrophysics Data System (ADS)

During the Miocene, orogenic gold deposits and lamprophyric magmas were emplaced contemporaneously in the proto-Southern Alps of New Zealand. These two systems have some striking similarities such as (1) the shared preferred orientations of the gold-bearing structures and the lamprophyric dikes, (2) the association with extensive, structurally controlled (dominantly Fe-rich) carbonate alteration, and (3) the shallow emplacement level into a quartzofeldspathic terrane. The abundance of the carbonate alteration is particularly notable as crustal sources for the CO2 such as marbles or carbonate minerals within the host rocks are very rare. A possible source could be related to the alkaline magmatic suite which, N of the study area, also contains mantle-derived carbonatites. To ascertain whether this could be the case, we have examined the geochemistry and isotopic properties of the Fe-carbonates that have precipitated in both systems, in veins as well as as replacing minerals within the host rock. The alteration haloes extend up to 10s of metres into the wallrock, where the replacement of metamorphic minerals such as chlorite and epidote distal to the fault zone attests to an extensive flux of CO2-rich fluids. Trace element data from these haloes, obtained in-situ using LA-ICP-MS, reveals introduction, mobilisation and redeposition of major and trace elements, such as Ca, K, Sr and REE. Sr isotope and trace element data suggest that the Fe-carbonates related to the lamprophyres have at least partly a genetic link to the carbonatites. Thus, some of the Miocene CO2 appears to have had a mantle origin. The carbonates related to the gold-bearing structures have more radiogenic 87Sr/86Sr ratios, which may be due to the interaction of the fluid with the relatively radiogenic host rocks as the signatures seem to depend on the type of wall rock (quartzofeldspathic- or greenschist). Tests are in progress to establish whether the gold-bearing carbonates could have formed by interaction of mantle derived fluids and crustal rocks.

Wellnitz, Katrin; Scott, James; Palin, Michael; Craw, Dave

2014-05-01

335

Field Trip Guide to Serpentinite, Silica-Carbonate Alteration, and Related Hydrothermal Activity in the Clear Lake Region, California  

SciTech Connect

This guide is designed to familiarize scientists with the geology, structure, alteration, and fluids typical of California serpentinites for purposes of carbon dioxide sequestration (Lackner et al., 1995). Goff et al. (1997) and Goff and Lackner (1998) describe the geology and geochemistry of some of the serpentinites from this area. Mechanisms of silica-carbonate alteration were outlined by Barnes et al. (1973). Donnelly-Nolan et al. (1993) most recently reviewed relations between regional hydrothermal alteration and Quarternary volcanic activity. Stanley et al. (1998) summarized geophysical characteristics of the region.

Fraser Goff; George Guthrie

1999-06-01

336

County digital geologic mapping. Final report  

SciTech Connect

The purpose of this project is to create quality-county wide digital 1:250,000-scale geologic maps from existing published 1:250,000-scale Geologic and Mineral Resource Bulletins published by the Nevada Bureau of Mines and Geology (NBMG). An additional data set, based on current NBMG research, Major and Significant Quaternary and Suspected Quaternary Faults of Nevada, at 1:250,000 scale has also been included.

Hess, R.H.; Johnson, G.L.; dePolo, C.M.

1995-12-31

337

Geology Fieldnotes: Capitol Reef National Park, Utah  

NSDL National Science Digital Library

This Capitol Reef National Park site contains park geology information, park maps, photographs, visitor information, and a teacher feature (resources for teaching geology with National Park examples). Geologic data includes descriptions of the Waterpocket Fold, a monocline formed in the Laramide Orogeny and made of sedimentary rock. Also covered is erosion, and details about the Cathedral Valley outcrop of gypsum. This formation is Permian to Cretaceous in age (270-80 million years old).

338

The Geologic History of Cape Cod, Massachusetts  

NSDL National Science Digital Library

Geologists are interested in Cape Cod, Massachusetts because it formed by glaciers very recently in terms of geologic time, and because of the ever-changing shore as the Cape adjusts to the rising sea. This United States Geological Survey (USGS) report covers the geologic history of the Cape, which includes glacial retreat, fossils, erosion, and the future of this area. Selected readings are given for further reference.

Oldale, Robert

339

Geology of interior cratonic sag basins  

SciTech Connect

Interior cratonic sag basins are thick accumulations of sediment, generally more or less oval in shape, located entirely in the interiors of continental masses. Some are single-cycle basins and others are characterized by repeated sag cycles or are complex polyhistory basins. Many appear to have developed over ancient rift systems. Interior cratonic sag basins are typified by a dominance of flexural over fault-controlled subsidence, and a low ratio of sediment volume to surface area of the basin. The Baltic, Carpentaria, Illinois, Michigan, Parana, Paris, and Williston basins are examples of interior cratonic sag basins. Tectonics played a dominant role in controlling the shapes and the geometries of the juxtaposed packets of sedimentary sequences. While the mechanics of tectonic control are not clear, evidence suggests that the movements are apparently related to convergence of lithospheric plates and collision and breakup of continents. Whatever the cause, tectonic movements controlled the freeboard of continents, altering base level and initiating new tectono-sedimentologic regimes. Sag basins situated in low latitudes during their development commonly were sites of thick carbonates (e.g., Illinois, Michigan, Williston, and Paris basins). In contrast, siliciclastic sedimentation characterized basins that formed in higher latitudes (e.g., Parana and Carpentaria basins). Highly productive sag basins are characterized by widespread, mature, organic-rich source rocks, large structures, and good seals. Nonproductive basins have one or more of the following characteristics: immature source rocks, leaky plumbing, freshwater flushing, and/or complex geology due to numerous intrusions that inhibit mapping of plays.

Leighton, M.W.; Eidel, J.J.; Kolata, D.R.; Oltz, D.F. (Illinois Geological Survey, Champaign (USA))

1990-05-01

340

Learning Assessment #5 - Geologic Time (2011)  

NSDL National Science Digital Library

Given a schematic cross-section and some background information about numerical ages, Part 1 of this activity asks students to give the relative time sequence of 14 geological events. In Part 2, students must provide numerical age brackets for a number of geologic events and/or rock units. In Part 3, students are asked to explain their reasoning for their age bracket assignments in part 2, including the principles of relative age they employed. Students are provided with a copy of the geologic time scale (2009, Geological Society of America) to assist them in completing this activity.

Reid, Leslie; Speta, Michelle

341

Geology Fieldnotes: Badlands National Park, South Dakota  

NSDL National Science Digital Library

Badlands National Park, located in southwestern South Dakota, consists of 244,000 acres of sharply eroded buttes, pinnacles and spires blended with the largest, protected mixed grass prairie in the United States. Features include information on park geology, maps, photographs, visitor information, links to related publications, and lesson plans for teaching geology with National Park examples. The park geology section discusses the Park's geologic history during the Eocene and Oligocene epochs and the rich fossil deposits found there. Maps of the park and the surrounding area are included.

342

Geology of Lake Mead National Recreation Area  

NSDL National Science Digital Library

This website of the United States Geological Survey (USGS) and National Park Service (NPS) highlights the geologic history of Lake Mead National Recreation Area in Nevada and Arizona. From the Precambrian (1.8 billion years ago) until the present, the Lake Mead region has been shaped by collisions, uplift, erosion, volcanic activity, submergence, extension, and sedimentation. This site covers these major events and when they occurred in the Lake Mead area. There are links to information about geologic maps, geologic time, rocks and minerals, plate tectonics, and other Lake Mead information sources.

343

Geologic Resource Evaluation of Kaloko-Honokohau National Historical Park, Hawaii; Geology and Coastal Landforms.  

National Technical Information Service (NTIS)

Geologic resource inventories of lands managed by the National Park Service (NPS) are important products for the parks and are designed to provide scientific information to better manage park resources. Park-specific geologic reports are used to identify ...

A. E. Gibbs B. M. Richmond S. A. Cochran

2009-01-01

344

Investigating SE MN Geology including rock layers, fossils, and Karst geology through Quarry Hill Nature Center  

NSDL National Science Digital Library

This activity is a field investigation where students will increase their knowledge of SE MN geology including rock layers, fossils, and Karst topography. They will also learn how Karst Geology impacts our water quality.

345

Symmetries in geology and geophysics.  

PubMed

Symmetries have played an important role in a variety of problems in geology and geophysics. A large fraction of studies in mineralogy are devoted to the symmetry properties of crystals. In this paper, however, the emphasis will be on scale-invariant (fractal) symmetries. The earth's topography is an example of both statistically self-similar and self-affine fractals. Landforms are also associated with drainage networks, which are statistical fractal trees. A universal feature of drainage networks and other growth networks is side branching. Deterministic space-filling networks with side-branching symmetries are illustrated. It is shown that naturally occurring drainage networks have symmetries similar to diffusion-limited aggregation clusters. PMID:11607719

Turcotte, D L; Newman, W I

1996-12-10

346

American Geological Institute: Educational Resources  

NSDL National Science Digital Library

Over the past few years, the American Geological Institute (AGI) has assembled a nice mix of resources for earth science educators, including promotional videos such as "Why Earth Science?" and a terrific world image bank. The image bank can be found at the "Earth Science World Image Bank" tab, and it contains over 6,000 images. Visitors can browse the images, or they can also type in keywords. The site also includes videos which originally appeared in the online version of "Earth" magazine. These short subjects cover "Black Gold Agriculture", "Platinum from the Deep", and "State of the Nation's Ecosystems". Visitors can also read their publication "Pulse of Earth Science Education", which offers an overview of the trends in the field.

2011-09-12

347

American Geological Institute: Educational Resources  

NSDL National Science Digital Library

Over the past few years, the American Geological Institute (AGI) has assembled a nice mix of resources for earth science educators, including promotional videos such as "Why Earth Science?" and a terrific world image bank. The image bank can be found at the "Earth Science World Image Bank" tab, and it contains over 6,000 images. Visitors can browse the images, or they can also type in keywords. The site also includes videos which originally appeared in the online version of "Earth" magazine. These short subjects cover "Black Gold Agriculture", "Platinum from the Deep", and "State of the Nation's Ecosystems". Visitors can also read their publication "Pulse of Earth Science Education", which offers an overview of the trends in the field.

348

Petroleum geology of western Antarctica  

SciTech Connect

Antarctica's geology is mostly obscured by thick, moving ice that covers 95% of the land and continental shelf. Reconnaissance investigations of outcrops, shallow boreholes, and geophysical surveys are limited and peripheral owing to ice coverage. However, it is possible to outline substantial elements of the regional geology. Further insight is gained by comparison to analogous sedimentary provinces, especially provinces once adjoined within the framework of the Gondwana supercontinent until middle Cretaceous. The petroleum potential of Antarctica, as in the case of the other related high-standing Gondwana continental fragments, is in Early Cretaceous rifts associated with the Gondwana breakup and with the Pacific convergence in the west Antarctica back arc. The Pacific-facing western Antarctica includes two structural provinces: (1) the Cretaceous and younger interior rift system on the east side of the Weddell and Ross Sea embayment, which contain aulacogens that form the boundary with East Antarctica and (2) the back-arc and fore-arc basins adjoining the Antarctica Peninsula and extending into Marie Byrd Land and the Bellingshausen Sea which are associated with the eastward convergence of the Pacific plate. The petroleum potential of the rifts may be assessed by analogies with related rifts of Australia, India, and South Africa; assessment of the convergent basins of western Antarctica depends upon analogy with similar basins of South America, New Zealand, and Indonesia. An estimate of the petroleum potential of western Antarctica generally is comparable with oil and gas occurrences (both in overall quantity and in field sizes) in the other Gondwana continental fragments. However, in view of the thict moving ice cover, the remote locale, and severe climate, petroleum production is largely beyond technology at this time and probably is economically unfeasible.

Kingston, J. (Geological Survey, Santa Barbara, CA (USA))

1990-05-01

349

Report on geologic exploration activities  

SciTech Connect

This report provides an overview of the geological exploration activities being carried out as part of the National Waste Terminal Storage (NWTS) Program, which has been established by the US Department of Energy (DOE) to develop the technology and provide the facilities for the safe, environmentally acceptable isolation of civilian high-level and transuranic nuclear wastes, including spent fuel elements, for which the Federal government is responsible. The principal programmatic emphasis is on disposal in mined geologic repositories. Explorations are being conducted or planned in various parts of the country to identify potential sites for such repositories. The work is being undertaken by three separate but coordinated NWTS project elements. Under the Basalt Waste Isolation Project (BWIP), basalt formations underlying DOE's Hanford Reservation are being investigated. Granite, tuff, and shale formations at the DOE Nevada Test Site (NTS) are being similarly studied in the Nevada Nuclear Waste Storage Investigations (NNWSI). The Office of Nuclear Waste Isolation (ONWI) is investigating domed salt formations in several Gulf Coast states and bedded salt formations in Utah and Texas. The ONWI siting studies are being expanded to include areas overlying crystalline rocks, shales, and other geohydrologic systems. The current status of these NWTS efforts, including the projected budgets for FY 1981, is summarized, and the criteria and methodology being employed in the explorations are described. The consistency of the overall effort with the recommendations presented in the Report to the President by the Interagency Review Group on Nuclear Waste Management (IRG), as well as with documents representing the national technical consensus, is discussed.

Breslin, J.; Laughon, R. B.; Hall, R. J.; Voss, J. W. [comps.

1980-01-01

350

CASP: Geological exploration and research  

SciTech Connect

The Cambridge Arctic Shelf Programme (CASP) is an independent, non-profit-making geological research organization based in the University of Cambridge. It originated in 1948 as Cambridge Spitsbergen Expeditions, and was incorporated as CASP in 1975. Initially, support came from companies with an interest in Svalbard and the Barents Shelf. Since then, CASP has greatly increased its scope, diversifying to new areas of research outside the Arctic and to new methods of data presentation. CASP now offers a unique programme of research, specialising in field- and literature-based studies of remote areas. Projects are currently being undertaken in the Arctic, Russia, China, East Greenland and Eastern Europe; all projects involve fieldwork and ail involve collaboration with research groups in other institutions. Most projects are oriented towards sedimentology, stratigraphy, tectonics, basin analysis and regional geology. CASP has a unique status: it shares elements in common with universities (undertaking long-term research programmes for eventual publication), consultancies (carrying out applied projects oriented towards hydrocarbon exploration and production) and national surveys (compiling and managing large datasets). Individual projects are funded by annual subscription from interested companies, with research material being supplied on a non-exclusive basis. Input and feedback from subscribers is welcomed, and an annual consortium meeting is organised for each project. As a non-profit-making Organization with low overheads, all additional income raised for a project is used to develop the research programme. CASP projects are supported by an outstanding library/information centre and linguistic expertise (Russian and Chinese), and these facilities are available to subscribing companies.

Macdonald, D.I.M.; Scott, R.A. [Cambridge Arctic Shelf Programme (United Kingdom)

1995-08-01

351

Global Geological Map of Venus  

NASA Astrophysics Data System (ADS)

Introduction: The Magellan SAR images provide sufficient data to compile a geological map of nearly the entire surface of Venus. Such a global and selfconsistent map serves as the base to address the key questions of the geologic history of Venus. 1) What is the spectrum of units and structures that makes up the surface of Venus [1-3]? 2) What volcanic/tectonic processes do they characterize [4-7]? 3) Did these processes operated locally, regionally, or globally [8- 11]? 4) What are the relationships of relative time among the units [8]? 5) At which length-scale these relationships appear to be consistent [8-10]? 6) What is the absolute timing of formation of the units [12-14]? 7) What are the histories of volcanism, tectonics and the long-wavelength topography on Venus? 7) What model(s) of heat loss and lithospheric evolution [15-21] do these histories correspond to? The ongoing USGS program of Venus mapping has already resulted in a series of published maps at the scale 1:5M [e.g. 22-30]. These maps have a patch-like distribution, however, and are compiled by authors with different mapping philosophy. This situation not always results in perfect agreement between the neighboring areas and, thus, does not permit testing geological hypotheses that could be addressed with a self-consistent map. Here the results of global geological mapping of Venus at the scale 1:10M is presented. The map represents a contiguous area extending from 82.5oN to 82.5oS and comprises ~99% of the planet. Mapping procedure: The map was compiled on C2- MIDR sheets, the resolution of which permits identifying the basic characteristics of previously defined units. The higher resolution images were used during the mapping to clarify geologic relationships. When the map was completed, its quality was checked using published USGS maps [e.g., 22-30] and the catalogue of impact craters [31]. The results suggest that the mapping on the C2-base provided a highquality map product. Units and structures: A limited set of material units and tectonic structures describes the geological situation on the surface of Venus (Fig. 1). The globally applicable stratigraphic sequence summarizing varieties of local to regional columns consists of the following units (from older to younger), the relative ages of which are established by relationships of embayment: Tessera (t) represents elevated regions deformed by multiple sets of tectonic structures. Densely lineated plains (pdl) are dissected by numerous subparallel narrow and short lineaments. Ridged plains (pr) commonly form elongated belts of ridges. Shield plains (psh) have numerous small volcanic edifices on the surface. Regional plains were divided into the lower (pr1) and the upper (pr2) units. The lower unit has uniform and relatively low radar albedo; the upper unit is brighter and often forms flow-like occurrences. Shield clusters (sc) are morphologically similar to psh but occur as small patches that postdate regional plains. Smooth plains (ps) have uniform and low radar albedo and occur near impact craters and at distinct volcanic centers. Lobate plains (pl) form fields of lava flows that are typically undeformed by tectonic structures and are associated with major volcanic centers. Several structural assemblages complicate the surface of the material units: Tessera-forming structures (ridges and grooves), belts of ridges, belts of grooves (structural unit gb), mountain belts (structural unit mt that occurs around Lakhmi Planum), wrinkle ridges, and rift zones (structural unit rt). The higly tectonized material and structural units such as t, pdl, pr, mt, and gb predate vast plains units such as psh and rp1. Wrinkle ridges deform all units that are older than units ps and pl. Smooth and lobate plains together with rift zones and shield clusters appear to be contemporaneous and form the top of the global stratigraphic column. Crater statistics: Two factors, the atmosphere screening [32-34] and the observational bias [35], appear to affect the statistics of the smaller craters on Venus. For the larger crater

Ivanov, M. A.

2008-09-01

352

Azithromycin alters macrophage phenotype  

Microsoft Academic Search

Methods: J774 cells were cultured in the presence of azithromycin and stimulated with classical acti- vation (interferon-g (IFNg)) and alternative activation (interleukin (IL)-4 and IL-13) cytokines along with lipopolysaccharide (LPS). Macrophages were analysed for inflammatory cytokine production, surface receptor expression, inducible nitric oxide synthase (iNOS) protein expression and arginase activity. Results: Azithromycin altered the overall macrophage phenotype. Azithromycin-treated J774 macro-

Brian S. Murphy; Vidya Sundareshan; Theodore J. Cory; Don Hayes Jr; Michael I. Anstead; David J. Feola

2008-01-01

353

Integration of DEM, ETM+, Geologic, and Magnetic Data for Geological Investigations in the Jifara Plain, Libya  

Microsoft Academic Search

We used an integrated approach to constrain the geological structure of the Jifara Plain in northwest Libya. The analysis of surface data, including a digital elevation model (DEM), Landsat Enhanced Thematic Mapper Plus images, and geologic maps, was combined with subsurface data, including well logs and magnetic data. The DEM data were used for the identification of geological lineaments in

Nureddin M. Saadi; Essam Aboud; Koichiro Watanabe

2009-01-01

354

An updated hydroclassification of streamflows at minimally-altered streamgages for the conterminous United States  

Microsoft Academic Search

The classification of streamflows at minimally-altered streamgages into river types based on similar hydrologic characteristics is important for many hydroecological studies ranging from assessing ecological flows to understanding the similarity between sites in streamgaging networks. The most recent national hydroclassification of streamflows, however, was completed over 15 years ago. Since that time, a newly published dataset of minimally-altered U.S. Geological

D. Wolock; S. A. Archfield; D. M. Carlisle; J. G. Kennen; K. Eng; J. E. Kiang

2010-01-01

355

Calculation of the conodont Color Alteration Index (CAI) for complex thermal histories  

Microsoft Academic Search

A simple model for the Arrhenius reaction conodont Color Alteration Index (CAI) that can be implemented easily in a computer program is introduced. The model, named to as EasyCAI, envisages the overall process of conodont alteration as a series of 12 parallel pseudo-first-order reactions. Our approach is especially amenable to a spreadsheet program and can solve complex geological histories involving

G. G. Voldman; R. A. Bustos-Marún; G. L. Albanesi

2010-01-01

356

Geology of the Fargo-Moorehead Region  

NSDL National Science Digital Library

This is a website created by University of North Dakota - Fargo faculty member Dr. Donald Schwert detailing the urban geology of the region surrounding Fargo, ND and Moorhead, MN. There is a good deal of information about the soils in the area, the Red River which flows North through the area, and the geologic history of why things are the way they are.

Schwert, Donald P.; University, North D.

357

Characterizing Geological Behavior based in Knowledge Acquisition  

Microsoft Academic Search

Generally, petroleum data sets are characterized by high noise, missing values and several geological considerations by experts. In this work, only the porosity and spatial informa- tion is used to describe permeability (an important attribute for petroleum geology) and to acquire knowledge using petroleum data sets. Three different scenarios using six well logs are sug- gested. The objective is to

Luis Carlos Molina; Solange Oliveira Rezende

358

Structural Geology Mapping/GIS Software  

NSDL National Science Digital Library

This site contains Stereographic Projection and Rose Diagram plotting packages (GEOrient); a structural and drillhole calculator (GeoCalculator); strain, and shear zone calculators; geological field database information; and Geographic Information Systems (Mapinfo) software for plotting structural symbols on maps (GeoMapSymbol; previously GeoSymbol]. There are also several animations for teaching structural geology.

Holcombe, Rod

359

APPLICATIONS OF GEOLOGY TO UNDERGROUND NUCLEAR EXPLOSIONS  

Microsoft Academic Search

Some programs in underground nuclear explosions are summarized insofar ; as they relate to the geographical sciences. It is shown that geological studies ; provide a more realistic picture of the environment around the explosion site and ; detailed refinements of the generalized picture of deformation and medium ; response. Various specific applications of geology to individual projects are ;

Short

1961-01-01

360

Digital Geological Mapping for Earth Science Students  

Microsoft Academic Search

This SPLINT (SPatial Literacy IN Teaching) supported project is developing pedagogies for the introduction of teaching of digital geological mapping to Earth Science students. Traditionally students are taught to make geological maps on a paper basemap with a notebook to record their observations. Learning to use a tablet pc with GIS based software for mapping and data recording requires emphasis

Richard England; Sally Smith; Nick Tate; Colm Jordan

2010-01-01

361

Wyoming Geology and Geography, Unit I.  

ERIC Educational Resources Information Center

This unit on the geology and geography of Wyoming for elementary school students provides activities for map and globe skills. Goals include reading and interpreting maps and globes, interpreting map symbols, comparing maps and drawing inferences, and understanding time and chronology. Outlines and charts are provided for Wyoming geology and…

Robinson, Terry

362

The Earth's Gravity and Its Geological Significance.  

ERIC Educational Resources Information Center

Discussed is the earth's gravity and its geological significance. Variations of gravity around the earth can be produced by a great variety of possible distributions of density within the earth. Topics discussed include isostasy, local structures, geological exploration, change of gravity in time, and gravity on the moon and planets. (DS)

Cook, A. H.

1980-01-01

363

Metaphor for the geologic time scale  

NSDL National Science Digital Library

This assignment serves as an introduction to the geologic time scale and to help students visualize the long time intervals between major events in Earth's history. The assignment encourages students to choose a metaphor for geologic time, research major events throughout Earth' history, and calculate how much (cumulative) of their metaphor each time interval represents.

Thompson, Cara

364

Monterey Bay National Marine Sanctuary: Geology  

NSDL National Science Digital Library

This reference describes the general geologic setting of the Monterey Bay National Marine Sanctuary. Topics include the physiography, geology and tectonics (structure, stratigraphy, mass wasting, and earthquake activity) of the Bay. There is also information on ground water, cold seeps, coastal erosion, and economic resources (petroleum, mineral resources, and building materials).

365

Yellowstone Geologic System Database (GeoGIS)  

NSDL National Science Digital Library

This website provides access to a broad collection of geographical, geological, and geophysical data for the Yellowstone/Snake River Plain volcanic system. Data types include physical geography, geology, geophysics, geodesy, regional models, and hazards. Information may be downloaded from lists of data, and links are provided to the original sources.

Group, University O.

366

US Geological Survey World Energy Project  

NSDL National Science Digital Library

The World Energy Project's Website holds a wide collection of data including province assessment reports and maps showing geology, oil and gas fields, and geologic provinces (Africa, Arabian Peninsula, South Asia, South America, Former Soviet Union, Asia Pacific Region, and Iran). Finally, a report ranks the world's oil and gas provinces by known petroleum volumes.

367

Advances in planetary geology, volume 2  

SciTech Connect

This publication is a continuation of volume 1; it is a compilation of reports focusing on research into the origin and evolution of the solar system with emphasis on planetary geology. Specific reports include a multispectral and geomorphic investigation of the surface of Europa and a geologic interpretation of remote sensing data for the Martian volcano Ascreaus Mons.

Not Available

1986-07-01

368

Advances in planetary geology, volume 2  

NASA Technical Reports Server (NTRS)

This publication is a continuation of volume 1; it is a compilation of reports focusing on research into the origin and evolution of the solar system with emphasis on planetary geology. Specific reports include a multispectral and geomorphic investigation of the surface of Europa and a geologic interpretation of remote sensing data for the Martian volcano Ascreaus Mons.

1986-01-01

369

Abstracts for the Planetary Geology Field Conference  

NASA Technical Reports Server (NTRS)

The conference was to foster a better understanding of the volcanic history of the planets through the presentation of papers and through field trips to areas on the basalt plains of Idaho that appear to be analogous to some planetary surfaces. Papers include discussions of the volcanic geology of the Snake River Plain, general volcanic geology, and aspects of volcanism on the terrestrial planets.

Greeley, R. (editor); Black, D.

1977-01-01

370

A Historical Approach for Teaching Introductory Geology.  

ERIC Educational Resources Information Center

Discusses several pedagogical merits to teaching geology with a historical emphasis. Describes how concepts of relative time, the field aspects of geology, and the cultural relationships of science can be applied in a historical approach to the subject. Shortcomings to this sort of approach are also mentioned. (CS)

Dott, R. H., Jr.

1980-01-01

371

Egypt's petroleum geology: Good grounds for optimism  

SciTech Connect

In the past eight years 30 operators have discovered 25 fields in Egypt. While most have been in the Gulf of Suez, the Western Desert, Which covers two-thirds of the country, and the Nile Delta are also prospective. This study discusses Egypt's regional geology as well as the geology of the individual significant recent discoveries.

Abdine, A.S.

1981-12-01

372

Reports of Planetary Geology Program, 1982  

NASA Technical Reports Server (NTRS)

Work conducted in the Planetary Geology program is summarized. The following categories are presented: outer solar system satellites; asteroids and comets; Venus; cratering processes and landform development; volcanic processes and landforms; aolian processes and landforms; fluvial processes and landform development; periglacial and permafrost processes; structure, tectonics and stratigraphy; remote sensing and regolith studies; geologic mapping, cartography and geodesy.

Holt, H. E. (compiler)

1982-01-01

373

Geologic maps of Pacific basin and rim  

SciTech Connect

A major component of the Circum-Pacific Map Project is to compile five regional geologic maps at a scale of 1:10 million and a final map of the Pacific Ocean basin at a scale of 1:17 million. The Geologic Map of the Northeast Quadrant was published in 1983, and the Geologic Map of the Southeast Quadrant in 1985. The Geologic Maps of the Northwest Quadrant, the Southwest Quadrant, and the Antarctic Region are expected to reach publication during 1986. The Geologic Map of the Pacific Basin, with energy and mineral resources, is scheduled for publication in 1989. Each geologic map is a synthesis of a large amount of information. The land areas portray rock types by patterns and ages by colors; major faults are shown if they form the boundaries for map units. The oceanic areas include bathymetric contours, 13 sea-floor sediment types, all Deep Sea Drilling Program (DSDP) sites, selected DSDP columns, and selected sites of pre-Quaternary bedrock or sediment recovery. A correlation diagram on each map shows stratigraphic columns for the five regional maps, map units, geologic ages, and a time scale. An inset map shows presently active tectonic plates. The principal information sources for each sheet are given in a reference list, and each map is accompanied by explanatory notes. This map series represents the first integrated set of geologic maps of the entire Pacific Ocean basin and rim, including the Antarctic continent- altogether more than half the surface area of planet Earth.

Craddock, C.

1986-07-01

374

Geologic History Field Investigation - Minnehaha Falls  

NSDL National Science Digital Library

This activity is an inquiry-based field investigation of the geologic history of the Minnehaha Falls and St. Anthony Falls areas of Minneapolis. Students will be introduced to rocks and the stories rocks tell in a genuine geologic context, rather than as samples in the classroom.

Kevin Swanson and Justin Larson, Chippewa Middle School, North Oaks, MN

375

Geologic Heritage in the National Parks  

NSDL National Science Digital Library

What is geologic heritage, you ask? In short, it "encompasses the significant geologic features, landforms, and landscapes characteristic of our Nation." The National Park Service has a special program to document these sites and to provide the public with resources about these unique destinations. The materials here are divided into four featured programs: Fossil Resources, Geologic Heritage Conservation, Park Geology Tour, and Cave and Karst Resources. Using the Park Geology Tour, visitors can search through thematic areas such as glaciers, fossils, and plate tectonics to find highlights from a vast array of National Park units. The Cave and Karst Resources program brings together resources on some of the over 4,900 caves in the National Park system, along with detailed photo galleries, newsletters, and brochures. Finally, under Fossil Resources visitors can find information about National Fossil Day and even helpful lesson plans for teachers.

2013-03-22

376

North Dakota geology school receives major gift  

NASA Astrophysics Data System (ADS)

Petroleum geology and related areas of study at the University of North Dakota (UND) received a huge financial boost with the announcement on 24 September of $14 million in private and public partnership funding. The university announced the naming of the Harold Hamm School of Geology and Geological Engineering, formerly a department within the College of Engineering and Mines, in recognition of $10 million provided as a gift by oilman Harold Hamm and Continental Resources, Inc. Hamm is the chair and chief executive officer of Continental, the largest leaseholder in the Bakken Play oil formation in North Dakota and Montana, and he is also an energy policy advisor to Republican presidential candidate Mitt Romney. UND also received $4 million from the Oil and Gas Research Program of the North Dakota Industrial Commission to support geology and geological engineering education and research.

Showstack, Randy

2012-10-01

377

Alaska Division of Geological and Geophysical Surveys  

NSDL National Science Digital Library

This is the homepage of Alaska's geological and geophysical survey, the agency responsible for collecting and distributing information about the state's geologic resources and hazards. Materials include numerous downloadable geologic publications, geophysical, geochemical, and GIS datasets, maps, photos, and news articles. The 'Guide to Alaska Geologic and Mineral Information', a document available at the site, is a source for basic and specialized research into the geology of Alaska, and the resources and issues involved in exploration for metallic mineral deposits in Alaska. It is designed to give users a broad overview of the many resources available to them from library facilities and holdings to State and Federal agencies that publish research and oversee mining and exploration activities to online databases, publications, and catalogs.

378

Mapping Vesta: A Geological Overview  

NASA Astrophysics Data System (ADS)

Observations from the Dawn (Russell et al., 2007) spacecraft enabled deriva-tion of 4Vesta's shape, facilitated mapping of the surface geology and pro-vided the first evidence for Vesta's geological evolution. The Dawn mission is equipped with a framing camera (FC), a visible and infrared mapping spectrometer (VIR) and a gamma-ray and neutron detector (GRaND). So far science data are collected during the approach to the asteroid and protoplanet Vesta, a circular polar orbit at an altitude of 2700 km providing ~ 230 m/pix camera resolution and a lower orbit, at 700 km altitude with a camera resolu-tion of ~ 65 m/pixel. Geomorphology and distribution of surface features provide evidence for impact cratering, tectonic activity, regolith and prob-able volcanic processes. Craters with dark rays, bright rays, and dark rim streaks have been observed, suggesting possible buried stratigraphy. The largest fresh craters retain a simple bowl-shaped morphology, with depth/diameter ratios roughly comparable to lunar values. The largest candi-date crater, a ~460 km depression at the south pole, has been shown to con-tain an incomplete inward facing cuspate scarp, and a large central mound surrounded by unusual complex arcuate ridge and groove patterns. Although asymmetric in general form, these characteristics do not contradict an impact origin but may also allow endogenic processes like convective downwelling or hybrid modification of an impact. Rapid rotation of Vesta during impact may explain some anomalous features (Jutzi and Asphaug, 2010). A set of large equatorial troughs may be related to the formation process of the south polar structure or due to stress caused by changes of the rotational axis. The crater size frequency and the chronology function is derived from the lunar chronology, scaled to impact frequencies modeled for Vesta according to (Bottke et al., 1994) and (O'Brien and Sykes, 2011). The northern hemi-sphere is heavily cratered by a large variety of ancient degraded and fresh sharp craters. Preliminary crater counts indicate only small differences in absolute surface model ages between the northern region and the south polar structure.

Jaumann, R.; Pieters, C. M.; Russell, C. T.; Raymond, C. A.; Yingst, R.; Williams, D. A.; Schenk, P.; Neukum, G.; Mottola, S.; Buczkowski, D.; O'Brien, D. P.; Garry, W. B.; Blewett, D. T.; Denevi, B. W.; Roatsch, T.; Preusker, F.; Nathues, A.; Sierks, H.; Sykes, M. V.; De sanctis, M.; McSween, H. Y.; Keller, H. U.; Marchi, S.

2011-12-01

379

Selection of colors and patterns for geologic maps of the U.S. Geological Survey  

USGS Publications Warehouse

U.S. Geological Survey (USGS) color and pattern standards and conventions for geologic maps have evolved since the USGS published its first set of standards in 1881. Since that time, USGS personnel have continuously updated and revised the standards in response to the need to show increasingly complex geologic map data and in response to changing technology. The color and pattern standards and conventions contained in this book enable geologists, cartographers, and editors to produce geologic maps that have consistent geologic-age color schemes and patterns. Such consistency enables geologists and other users of geologic maps to obtain a wealth of geologic information at a glance and to produce maps that can easily be used and compared to other published maps that follow the color and pattern standards and conventions.

Geological Survey (U.S.)

2005-01-01

380

Genetically Altered Plant Species  

NASA Technical Reports Server (NTRS)

Researchers in Robert Ferl's lab at the University of Florida in Gainesville, genetically altered this Arabdopsis Thaliana (a brassica species) plant to learn how extreme environments, such as the low atmospheric pressure on Mars, affect plant genes. They inserted green fluorescent protein (GFP) near the on/off switches for anoxia and drought genes. When those genes were turned on after exposure to reduced atmospheric pressure, GFP was turned on as well, causing cells expressing those genes to glow green under a blue light. The natural fluorescence of chlorophyll accounts for the red glow.

2003-01-01

381

Alteration mapping at Goldfield, Nevada, by cluster and discriminant analysis of Landsat digital data. [mapping of hydrothermally altered volcanic rocks  

NASA Technical Reports Server (NTRS)

The ability of Landsat multispectral digital data to differentiate among 62 combinations of rock and alteration types at the Goldfield mining district of Western Nevada was investigated by using statistical techniques of cluster and discriminant analysis. Multivariate discriminant analysis was not effective in classifying each of the 62 groups, with classification results essentially the same whether data of four channels alone or combined with six ratios of channels were used. Bivariate plots of group means revealed a cluster of three groups including mill tailings, basalt and all other rock and alteration types. Automatic hierarchical clustering based on the fourth dimensional Mahalanobis distance between group means of 30 groups having five or more samples was performed using Johnson's HICLUS program. The results of the cluster analysis revealed hierarchies of mill tailings vs. natural materials, basalt vs. non-basalt, highly reflectant rocks vs. other rocks and exclusively unaltered rocks vs. predominantly altered rocks. The hierarchies were used to determine the order in which sets of multiple discriminant analyses were to be performed and the resulting discriminant functions were used to produce a map of geology and alteration which has an overall accuracy of 70 percent for discriminating exclusively altered rocks from predominantly altered rocks.

Ballew, G.

1977-01-01

382

Geology and Metal Contents of the Ruttan volcanogenic massive sulfide deposit, northern Manitoba, Canada  

NASA Astrophysics Data System (ADS)

The Paleoproterozoic Ruttan Cu-Zn volcanogenic massive-sulfide (VMS) deposit is a large, relatively low grade, bimodal-siliciclastic type deposit in the Rusty Lake volcanic belt of northern Manitoba. The deposit contained over 82.8 million tonnes of massive sulfide, of which 55.7 million tonnes were mined from 1973 to 2002. The deposit consists of a series of moderately to steeply dipping, south-facing lenses that extend along strike at the surface for 1.1 km and to a depth of 1.0 km. These lenses occur within a steeply dipping, bimodal volcanic, volcaniclastic and siliciclastic sequence. In the immediate mine area, transitional calc-alkalic to high-silica (tholeiitic), felsic, and intermediate volcanic/volcaniclastic rocks of the Mine Sequence are host to, and intercalated with, the massive-sulfide lenses. Transitional tholeiitic to calc-alkalic basalt and andesite are present in the footwall sequence, approximately 500 m down-section from the ore horizon. The overlying rocks are predominantly fine-grained volcaniclastics and siliciclastics, but include polyfragmental agglomerate that contains mafic bombs and scoriaceous felsic fragments. Syn-depositional felsic and mafic dikes, sills, and apophyses are ubiquitous throughout the Mine Sequence, including the ore lenses, indicating continued, near-vent magmatism, and volcanism during ore formation. Fabrics in altered hostrocks have consistent, down-plunge stretching lineations to the SSE that suggest the deposit has been elongated by a factor of ~1.2-1.5; otherwise, the deposit is remarkably undeformed. Syn- and post-depositional faults in the mine area have relatively minor displacements up to tens of meters. Proximal (within 200 m) footwall rocks exhibit moderate to strong chloritization, characterized by the upper greenschist to lower amphibolite facies assemblages that include cordierite-almandine-andalusite-sillimanite-biotite ± staurolite ± anthophyllite ± talc, and local silicification. The proximal hanging wall rocks are characterized by sericite ± gahnite alteration, which is restricted to within approximately 75 m of the uppermost lenses. Additional gangue minerals are anhydrite and carbonate minerals (siderite, dolomite, ankerite, and calcite), as well as chlorite, sericite, biotite, talc, and quartz. Carbonate (excluding siderite), potassium feldspar, silicification and epidotization are common distal alteration zones in the footwall to the Mine Sequence several kilometers to the northeast. There are three principal groups of massive sulfide lenses; the East lenses, the West lenses, and the Western Anomaly lenses to the far west. In general, Cu is relatively enriched at the stratigraphic base and in the center of the deposit, whereas Zn is enriched upsection and at the outer margins. Some of the Zn-rich ore exhibits primary mineralogical layering. Parts of the West and Western Anomaly lenses show two layers with Cu-rich bases and Zn-rich tops. The massive sulfide is typically 10-40-m thick; one area along the margin of the main lenses is over 130-m thick and may represent deposition adjacent to a syn-depositional fault. The main sulfide phases are pyrite, pyrrhotite, chalcopyrite, sphalerite, and galena, with tetrahedrite as the most abundant trace phase. Gahnite is ubiquitous in the chlorite-rich assemblages adjacent to the ore lenses. The average base, precious and trace metal contents estimated from Cu and Zn concentrates, and from millhead grades and recoveries. Metals easily transported as chloride and bisulfide complexes in hydrothermal fluids including: Pb, Ag, In, Cu, Cd, Au, and Zn are enriched by 1.5-2.5 orders of magnitude in comparison to the bulk continental crust. Other elements such as Sn, Mo, and As are at near-crustal concentrations, whereas Mn, Ga, and Co are significantly depleted in comparison to the crust. Calculated metal concentrations in the average hydrothermal fluid based on the average metal contents are comparable to, or higher than those measured at sediment covered ridge hydrothermal systems, which precipitate much of their me

Barrie, C. Tucker.; Taylor, Craig; Ames, Doreen E.

2005-03-01

383

Thematic Conference on Geologic Remote Sensing, 8th, Denver, CO, Apr. 29-May 2, 1991, Proceedings. Vols. 1 & 2  

NASA Technical Reports Server (NTRS)

The proceedings contain papers discussing the state-of-the-art exploration, engineering, and environmental applications of geologic remote sensing, along with the research and development activities aimed at increasing the future capabilities of this technology. The following topics are addressed: spectral geology, U.S. and international hydrocarbon exporation, radar and thermal infrared remote sensing, engineering geology and hydrogeology, mineral exploration, remote sensing for marine and environmental applications, image processing and analysis, geobotanical remote sensing, and data integration and geographic information systems. Particular attention is given to spectral alteration mapping with imaging spectrometers, mapping the coastal plain of the Congo with airborne digital radar, applications of remote sensing techniques to the assessment of dam safety, remote sensing of ferric iron minerals as guides for gold exploration, principal component analysis for alteration mappping, and the application of remote sensing techniques for gold prospecting in the north Fujian province.

1991-01-01

384

Global Warming in Geologic Time  

ScienceCinema

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.

385

Global Warming in Geologic Time  

ScienceCinema

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.

David Archer

2010-01-08

386

Antarctica: geology and hydrocarbon potential  

SciTech Connect

The first impression of the hydrocarbon potential of Antarctica is generally negative. The environment is hostile and only 2% of the continent is seen through the ice. Careful study of the surprisingly ample volume of published data available on the geology and geophysics and Antarctica, coupled with the application of the principles and mechanics of plate tectonics relative to the oceans and adjacent land masses, gives a different and very positive attitude toward the hydrocarbon potential of this vast unexplored frontier area. On the basis of limited data, 21 sedimentary basins are identified for Antarctica and immediately adjacent areas. These include six onshore subglacial basins and 15 offshore basins. Excluding 11 basins considered to have little or no potential, the other 10 basins contain an estimated 16.9 million km/sup 3/ (4.05 million mi/sup 3/) of sediment having a potential hydrocarbon yield of 203 billion bbl oil equivalent. The problems associated with hydrocarbon exploration in Antarctica are formidable. Technology is adequate for seismic surveys and exploratory drilling of the Antarctic continental shelf, as concluded from current operations in the Arctic and from operating requirements of drilling rigs under construction. However, a working relationship among involved nations must first be evolved and production, storage, and transportation problems solved.

St. John, B.

1984-09-01

387

Global Warming in Geologic Time  

SciTech Connect

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.

David Archer

2008-02-27

388

Global Warming in Geologic Time  

SciTech Connect

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.

Archer, David (University of Chicago) [University of Chicago

2008-02-27

389

Structural geology of impact craters  

NASA Astrophysics Data System (ADS)

The formation of impact craters is a highly dynamic and complex process that subjects the impacted target rocks to numerous types of deformation mechanisms. Understanding and interpreting these styles of micro-, meso- and macroscale deformation has proved itself challenging for the field of structural geology. In this paper, we give an overview of the structural inventory found in craters of all size ranges on Earth, and look into the structures of craters on other planetary bodies. Structural features are discussed here that are caused by i) extremely high pressures and temperatures that occur during the initial passage of the shock wave through the target rock and projectile, ii) the resulting flow field in the target that excavates and ejects rock materials, and iii) the gravitationally induced modification of the crater cavity into the final crater form. A special focus is put on the effects that low-angle impacting bodies have on crater formation. We hope that this review will help both planetary scientists and structural geologists understand the deformation processes and resulting structures generated by meteorite impact.

Kenkmann, Thomas; Poelchau, Michael H.; Wulf, Gerwin

2014-05-01

390

Subsurface geological and geophysical study of the Cerro Prieto geothermal field, Baja California, Mexico  

SciTech Connect

The subsurface investigation of the Cerro Prieto field and surrounding area is described including the stratigraphy, structure, hydrothermal alteration, and reservoir properties for use in designing reservoir simulation models and planning development of the field. Insights into the depositional, tectonic, and thermal history of the area are presented. The following types of data were used: well sample descriptions and analyses, well logs, geophysical surveys; physiography, and regional geology. (MHR)

Lyons, D.J.; van de Kamp, P.C.

1980-01-01

391

Representative Indicators of Hydrologic Alteration  

Microsoft Academic Search

A few overall indicators of hydrologic alteration are needed to describe the health of a river and the degree of hydrologic alteration caused by various forms of river regulation. Currently over 170 hydrologic indicators have been developed to describe different components of flow regimes. One example is the Indicators of Hydrologic Alteration (IHA), a set of 33 indicators for characterizing

Yongxuan Gao; Richard M. Vogel; Charles N. Kroll; N. LeRoy Poff; Julian D. Olden

392

25 CFR 212.56 - Geological and geophysical permits.  

Code of Federal Regulations, 2010 CFR

...Appeals § 212.56 Geological and geophysical...Permits to conduct geological and geophysical...information for the time prescribed in the permit. Where no time period is prescribed...permit to conduct geological and...

2009-04-01

393

25 CFR 211.56 - Geological and geophysical permits.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Geological and geophysical permits...Appeals § 211.56 Geological and geophysical permits. Permits to conduct geological and geophysical operations...proprietary information for the time prescribed in the...

2010-04-01

394

25 CFR 211.56 - Geological and geophysical permits.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Geological and geophysical permits...Appeals § 211.56 Geological and geophysical permits. Permits to conduct geological and geophysical operations...proprietary information for the time prescribed in the...

2013-04-01

395

25 CFR 212.56 - Geological and geophysical permits.  

Code of Federal Regulations, 2013 CFR

...Appeals § 212.56 Geological and geophysical...Permits to conduct geological and geophysical...information for the time prescribed in the permit. Where no time period is prescribed...permit to conduct geological and...

2013-04-01

396

25 CFR 211.56 - Geological and geophysical permits.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Geological and geophysical permits...Appeals § 211.56 Geological and geophysical permits. Permits to conduct geological and geophysical operations...proprietary information for the time prescribed in the...

2009-04-01

397

25 CFR 212.56 - Geological and geophysical permits.  

Code of Federal Regulations, 2010 CFR

...Appeals § 212.56 Geological and geophysical...Permits to conduct geological and geophysical...information for the time prescribed in the permit. Where no time period is prescribed...permit to conduct geological and...

2010-04-01

398

Use of Library Readings to Augment Conventional Geology Instruction.  

ERIC Educational Resources Information Center

Examples of sets of questions on library readings designed to lead students into articles and emphasize important information and associated literature are presented for introductory geology courses, historical geology, structural geology, mineralogy, and petrology. (Author/CW)

Nold, John Lloyd

1989-01-01

399

Contribution of LANDSAT-4 thematic mapper data to geologic exploration  

NASA Technical Reports Server (NTRS)

The increased number of carefully selected narrow spectral bands and the increased spatial resolution of thematic mapper data over previously available satellite data contribute greatly to geologic exploration, both by providing spectral information that permits lithologic differentiation and recognition of alteration and spatial information that reveals structure. As vegetation and soil cover increase, the value of spectral components of TM data decreases relative to the value of the spatial component of the data. However, even in vegetated areas, the greater spectral breadth and discrimination of TM data permits improved recognition and mapping of spatial elements of the terrain. As our understanding of the spectral manifestations of the responses of soils and vegetation to unusual chemical environments increases, the value of spectral components of TM data to exploration will greatly improve in covered areas.

Everett, J. R.; Dykstra, J. D.; Sheffield, C. A.

1983-01-01

400

Geology and Geochemistry of the Lac Cinquante Uranium Deposit, Nunavut  

NASA Astrophysics Data System (ADS)

The Lac Cinquante Uranium Deposit, is located in the Kivalliq district of Nunavut approximately 350 km west of Rankin Inlet, and is centered on approximately Latitude 62°34'33"N, Longitude 98°41'41"W. Geologically it is located within the Baker Lake Basin of the Churchill province, one of several northeast- trending Proterozoic basins in the Western Churchill Province that lie unconformably on top of Archean volcanics. Mineralization is found within basement volcanics that have undergone hydrothermal alteration and mineralization in fault zones. Previous studies of this area document two major zones of mineralization: the Main zone and the South zone; with three dominant styles of mineralization in the Archean greenstones including: disseminated pitchblende with base metals in tuffaceous metasediments, discrete pitchblende veins that cut across the metasediments, and quartz, carbonate, sulphides, and pitchblende in gash veins on 040 to 060 trending cross fractures. Additionally, mineralized zones hosting uranium are also present in the overlying Proterozoic sediments. Field based mapping completed in the summer of 2008 at 1:5000 has revealed a more detailed and complicated geological history than previously reported. The newly acquired map and historical data have been combined in an attempt to develop a comparative data collection. Geochemical data has aided in a more developed interpretation for the formation of the greenstone belt within which the Lac Cinquante uranium deposit is hosted. Current analytical techniques complementing the geological observations include X-ray diffraction to determine mineral assemblages and X-ray fluorescence for major and trace element information. Other analytical techniques will be utilised including electron microprobe to understand precise mineral chemistry of uranium bearing minerals, oxygen stable isotopes to understand fluid migration and ore forming reservoirs, and further stable isotope analyses to understand the temperature and mineral-fluid interactions leading to uranium mineralization are planned.

Bridge, N. J.; Banerjee, N. R.; Finnigan, C. S.; Carpenter, R.; Ward, J.

2009-05-01

401

Updating of the geological and geothermal research on Milos island  

SciTech Connect

The oldest geologic formations outcropping in Milos are an Alpine age crystalline basement and a transgressive marine Neogene sequence. The island is mainly volcanic. It belongs to the Aegean Active Arc, within which the Milos archipelago shows the most important volcanism in terms of quantity, variety of products and duration of activity (3.5-0.8 M.a.). There are no large central volcanic edifices but different, frequently coeval eruption centres. The initial and intermediate phases of activity were mainly pyroclastic and submarine, whereas the last one (0.1 M.a.) was subaerial and formed tuff rings, surge deposits and lava flows, all of homogenous rhyolitic composition. Recent detailed studies have addressed the mechanism of feeding and the type of magmatic chambers beneath Milos. Distention tectonics have two main phases: an earlier one (Pliocene) with NE-SW direction and a much more intense recent (Quaternary) one, trending NW-SE. The geological, tectonic and magmatic activity favoured the formation of a high enthalpy geothermal field. Many fossil and active thermal manifestations exist: hot springs, fumaroles, hot grounds, phreatic explosion craters. The hydrothermal alteration of the volcanites produced, by self sealing, a perfect cover for the geothermal fluids. Geothermometry of the surface fluids indicated high values for the source temperatures and very high geothermal gradients in central and eastern Milos. Geothermally anomalous zones, defined by two different methods, together with superficial geological and tectonic information, permitted the location of sites for deep drilling. Five exploratory wells 1000-1400m deep gave satisfactory results of flow rate (40-120 t/h), temperature (300-320{sup 0}C) and enthalpy.

Fytikas, M. (Institute for Geology and Mineral Exploration, 70 Messoghion Ave., Athens (GR))

1989-01-01

402

The Geologic Story of Yosemite Valley  

NSDL National Science Digital Library

This website of the United States Geological Survey (USGS) and the National Park Service (NPS) discusses the geology of Yosemite Valley in California, beginning 100 million years ago with the formation of the granite rocks found in this park and continuing with jointing, exfoliation, and erosion through ice and water. Bedrock Geology includes details about the formation, classification, and descriptions of the plutonic bedrock. It also discusses the relationship of landforms to rock composition and structure and their role in shaping the Yosemite valley.

Huber, N.

403

Introduction to petroleum geology. Second edition  

SciTech Connect

This petroleum geology text has been updated to cover the latest developments in structural geology and applied geophysics. This new revision of the second edition brings together a treatment of both the theoretical and the practical aspects of oil and gas geology, explaining the current techniques of geophysical exploration and subsurface reservoir delineation. The latest advances in computerized imaging from remote sensing and satellite transmission mapping processes are provided, and special attention is given to geochemcial aspects of source rock evaluation, maturity analysis, and the evolution of kerogenous materials. The history and classification of sedimentary basing is described in relation to their past and present hydrocarbon contents and the movement of lithospheric ''plates.''

Hobson, G.D.; Tiratsoo, E.N.

1985-01-01

404

Geology Fieldnotes: Bryce Canyon National Park, Utah  

NSDL National Science Digital Library

Located on the Colorado Plateau in Utah, this canyon is comprised mostly of sedimentary rocks, and continues to be eroded and shaped by the Paria River. Its geologic and human history are outlined on this site, including the formation of the canyon, from the Cretaceous period (144 million years ago) to the present, and geologic features, such as fins, columns, pinnacles, and hoodoos. Visitor information, links to other resources, maps, and a teacher feature (resources for teaching geology with National Park examples) are also available.

Foos, Annabelle

405

Geology of Death Valley National Park  

NSDL National Science Digital Library

This site of the United States Geologic Survey (USGS) and the National Park Service (NPS) highlights the geologic history of Death Valley National Park in Nevada and California. The story begins 1.8 billion years ago with the formation of rocks and continues through uplift, faulting, volcanism, early animals of the area, glaciers, and the making of deserts and dunes. A geologic timescale connects to specific events in the history of Death Valley. There are topographic maps of the area, a field trip of the park, an image gallery, and technical papers available to download.

406

Geology of Massachusetts and Rhode Island  

USGS Publications Warehouse

In preparing the present treatise and the accompanying geologic map of Massachusetts and Rhode Island (PI. X, in pocket) I have endeavored to use all the material available. The matter has been greatly condensed, for the detailed geology of a considerable part of the area will be described in a number of forthcoming folios of the Geologic Atlas of the United States. The Holyoke folio, published in 1898, covered the major part of the Triassic rocks in Massachusetts, but as those rocks have since been more thoroughly studied they are here treated in greater detail to bring their discussion up to date.

Emerson, Benjamin Kendall

1917-01-01

407

Basic petroleum geology, 2nd Ed  

SciTech Connect

It presents the fundamental concepts of geology in terms of sedimentary deposition, petroleum occurrence, exploration, and recovery. It provides an integrated overview of petroleum geology concepts and vocabulary in easy to understand language. It is essential that geologists, geophysicists, and engineers share a common understanding of geologic processes which are presented in this book. It is just as important that petroleum managers, landmen, and technicians, as well as attorneys, financiers, and other nontechnical professionals be conversant with the terminology and fundamental principles of petroleum occurrence, exploration, and production.

Link, P.K.

1988-01-01

408

Tour of Park Geology: Sand Dunes  

NSDL National Science Digital Library

This Park Geology site provides links to tours of individual National Parks, Monuments, and Recreation Areas with sand dunes. Where appropriate for each park, links are provided to maps, photographs, geologic research, related links, visitor information, and teacher features (resources for teaching geology with National Park examples). The list includes places such as Death Valley and Mojave National Preserve, along with less well-known areas such as the Pictured Rocks National Lakeshore in Michigan and the Wright Brothers National Memorial in North Carolina.

409

Revised draft: Southeastern Regional geologic characterization report. Volume 1  

SciTech Connect

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Georgia, Maryland, North Carolina, South Carolina, and Virginia. For each of the states within the southeastern region, information is provided on the disqualifying factor and the screening variables to be used in region-to-area screening. These factors and variables include hydrologically significant natural resources, rock mass extent, postemplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major ground-water discharge zones, water resources, ground-water salinity, and state of stress. Information is presented on the age, areal extent, shape, thickness of overburden, composition, texture, degree and type of alteration, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the subject rock bodies. A discussion of the relationship between the DOE Siting Guidelines and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process is also presented.

Not Available

1984-11-01

410

Revised draft: North Central Regional geologic characterization report. Volume 1  

SciTech Connect

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the disqualifying factor and the screening variables to be used in region-to-area screening. These factors and variables include hydrologically significant natural resources, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, water resources, groundwater salinity, and state of stress. Information is presented on age, areal extent, shape, thickness of overburden, composition, texture, degree and type of alteration, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the subject rock bodies. A discussion of the relationship between the DOE Siting Guidelines and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process is also presented.

Not Available

1984-11-01

411

Multisource geological data mining and its utilization of uranium resources exploration  

NASA Astrophysics Data System (ADS)

Nuclear energy as one of clear energy sources takes important role in economic development in CHINA, and according to the national long term development strategy, many more nuclear powers will be built in next few years, so it is a great challenge for uranium resources exploration. Research and practice on mineral exploration demonstrates that utilizing the modern Earth Observe System (EOS) technology and developing new multi-source geological data mining methods are effective approaches to uranium deposits prospecting. Based on data mining and knowledge discovery technology, this paper uses multi-source geological data to character electromagnetic spectral, geophysical and spatial information of uranium mineralization factors, and provides the technical support for uranium prospecting integrating with field remote sensing geological survey. Multi-source geological data used in this paper include satellite hyperspectral image (Hyperion), high spatial resolution remote sensing data, uranium geological information, airborne radiometric data, aeromagnetic and gravity data, and related data mining methods have been developed, such as data fusion of optical data and Radarsat image, information integration of remote sensing and geophysical data, and so on. Based on above approaches, the multi-geoscience information of uranium mineralization factors including complex polystage rock mass, mineralization controlling faults and hydrothermal alterations have been identified, the metallogenic potential of uranium has been evaluated, and some predicting areas have been located.

Zhang, Jie-Lin

2009-10-01

412

Mitochondrial alterations in apoptosis.  

PubMed

Besides their conventional role as energy suppliers for the cell, mitochondria in vertebrates are active regulators of apoptosis. They release apoptotic factors from the intermembrane space into the cytosol through a mechanism that involves the Bcl-2 protein family, mediating permeabilization of the outer mitochondrial membrane. Associated with this event, a number of additional changes affect mitochondria during apoptosis. They include loss of important mitochondrial functions, such as the ability to maintain calcium homeostasis and to generate ATP, as well as mitochondrial fragmentation and cristae remodeling. Moreover, the lipidic component of mitochondrial membranes undergoes important alterations in composition and distribution, which have turned out to be relevant regulatory events for the proteins involved in apoptotic mitochondrial damage. PMID:24732580

Cosentino, Katia; García-Sáez, Ana J

2014-07-01

413

Use of Ontology for Field Geological Data in Geological Sheet Maps at 1:50,000: "Outcrop Information Vocabulary" Prototype  

NASA Astrophysics Data System (ADS)

Geological Survey of Japan has published series of geological map at 1:50,000. The study attempts to acquire, distribute, and utilize the outcrop information as digital information. We aim at construction of an open system which is available in a various position, and then establishment of standard technology for the realization of the system. The purpose of this paper is to consider and carry out manufacture of “Outcrop Information Vocabulary(OIV)” as the first stage of the study. Since outcrop information is basic primary information, the semantic web technology is employed to associate with various other systems on the Web; for instance, OIV is designed with use of ontology and described by Web Ontology Language(OWL). The OIV includes 14 classes including “FieldObservation” class to describe field observation. Moreover, we create test system which field researchers use to test the effectiveness of OIV. The result lead to the conclusion that files created by use of OIV are easy of mutual alteration and association function with other XML-base format, therefore, OIV has high affinity with existing technology. ULM Class Diagram for "Outcop Informaion Vocabulary"

Nishioka, Y.; Fusejima, Y.; Takarada, S.; Iwaya, T.; Igawa, T.; Masaka, Y. A.

2010-12-01

414

A LONG, LONG time ago: geologic timescales  

NSDL National Science Digital Library

Each student randomly picks a card with a geologic event (written description and an image) on it. A timeline has 11 events, not including the formation of the Earth and today. Students attach their event where they think it should go on a 45.5' timeline (in the hallway) made out of paper adding tape and mark the location on the timeline. They return to the classroom and receive a list of age dates for each event. Each group figures out the scale (1 foot = 100 million years) and then moves their events to the correct locations. Students are asked how the position of the events changed, and answer other questions that reinforce the difference between human timescales and geologic timescales. The powerpoint file below contains a template for making geologic event labels for the index cards. Instructors can tailor the geologic event list to fit their course.

Johnson, Elizabeth

415

Geomorphology in North American Geology Departments, 1971  

ERIC Educational Resources Information Center

Presents results of a 1970-71 survey of 350 geomorphologists and geology departments to determine what sort of geomorphology is being taught in the colleges and universities of the United States and Canada. (PR)

White, Sidney E.; Malcolm, Marshall D.

1972-01-01

416

Nevada Bureau of Mines and Geology  

NSDL National Science Digital Library

The Nevada Bureau of Mines and Geology, part of the Mackay School of Earth Sciences and Engineering at the University of Nevada, Reno, is an active and interesting source for studying mining and geology in the Southwestern United States. The Bureau's website includes quite a bit of information that would be of interest to students, researchers, and laypeople alike. Users will find information about current research projects on a variety of topics, an archive of presentations, and many different geologic maps of Nevada. Under the site's Data/Imagery/Indexes section, visitors will find interactive maps with data on geothermal resources, mineral resources, quaternary faults, and more. Most of the information provided pertains to the state of Nevada, but would also prove useful for instructors who could use the state's rich mining and geologic history and resources as teaching examples.

417

Remote geologic structural analysis of Yucca Flat.  

National Technical Information Service (NTIS)

The Remote Geologic Analysis (RGA) system was developed by Pacific Northwest Laboratory (PNL) to identify crustal structures that may affect seismic wave propagation from nuclear tests. Using automated methods, the RGA system identifies all valleys in a d...

K. A. Hoover M. G. Foley N. J. Rynes P. G. Heasler R. L. Thiessen

1991-01-01

418

Magellan Stereo Images and Venusian Geology.  

National Technical Information Service (NTIS)

Areas of Venus imaged by Magellan radar with multiple viewing conditions provide unique data that will contribute to the solution of venusian geologic problems and provide a basis for quantitative comparison of venusian landforms with those on other plane...

H. J. Moore R. S. Saunders J. J. Plaut T. J. Parker

1992-01-01

419

Geology and Radiometry of West Macedonia (Greece).  

National Technical Information Service (NTIS)

Car borne scintillometry survey in W. Macedonia (Greece) showed that the granitic rocks of the area, the zone centered on the Tertiary volcanic rocks of Almopia zone and a large part of adjacent sediments constitute the most promising geological formation...

D. G. Minatidis

1984-01-01

420

Coastal Gneiss in Blekinge, Geology and Hydrogeology.  

National Technical Information Service (NTIS)

The present work deals with the geology and the tectonics of the Precambrian of Blekinge in the southeastern Sweden. After comprehensive field studies of the tectonics of western Blekinge a tectonic-morphologic map was constructed. Statistical investigati...

I. Larsson U. Wiklander T. Lundgren

1977-01-01

421

Reports of planetary geology program, 1980. [Bibliography  

NASA Technical Reports Server (NTRS)

This is a compilation of abstracts of reports which summarize work conducted in the Planetary Geology Program. Each report reflects significant accomplishments within the area of the author's funded grant or contract.

Holt, H. E. (compiler); Kosters, E. C. (compiler)

1980-01-01

422

Bulletin (Geology). Series A, Number 27, 1969.  

National Technical Information Service (NTIS)

The document contains geotectonic reports from Yugoslavia. Some titles are the following: The older styrian stage in the tectonics of eastern Serbia; Geology and tectonics of the surroundings of the Bor copper mine with reference to Cu-mineralization; For...

1969-01-01

423

Geology and Alteration of the Baltazor Hot Springs and Painted Hills Thermal Areas, Humboldt County, Nevada.  

National Technical Information Service (NTIS)

The Baltazor Hot Springs KGRA and nearby Painted Hills thermal area are situated in Humboldt County, northwestern Nevada along the northwestern margin of the Basin and Range province. The oldest rocks exposed in the Baltazor area are eugeosynclinal metase...

J. B. Hulen

1979-01-01

424

Geological and geothermal investigations for HCMM-derived data. [hydrothermally altered areas in Yerington, Nevada  

NASA Technical Reports Server (NTRS)

An attempt was made to match HCMM- and U2HCMR-derived temperature data over two test sites of very local size to similar data collected in the field at nearly the same times. Results indicate that HCMM investigations using resolutions cells of 500 m or so are best conducted with areally-extensive sites, rather than point observations. The excellent quality day-VIS imagery is particularly useful for lineament studies, as is the DELTA-T imagery. Attempts to register the ground observed temperatures (even for 0.5 sq mile targets) were unsuccessful due to excessive pixel-to-pixel noise on the HCMM data. Several computer models were explored and related to thermal parameter value changes with observed data. Unless quite complex models, with many parameters which can be observed (perhaps not even measured (perhaps not even measured) only under remote sensing conditions (e.g., roughness, wind shear, etc) are used, the model outputs do not match the observed data. Empirical relationship may be most readily studied.

Lyon, R. J. P.; Prelat, A. E.; Kirk, R. (principal investigators)

1981-01-01

425

Lessons from Natural Analog Studies for Geologic Disposal of High-Level Nuclear Waste (Invited)  

NASA Astrophysics Data System (ADS)

For over fifty years natural analog studies have provided lessons addressing scientific, technical, and social problems concerning geologic disposal of high-level nuclear waste. Idealized concepts for permanent disposal environments evolved from an understanding of the geological, geochemical and hydrological characteristics of analogous rocks including natural salt deposits (as advocated by the US National Academy of Sciences in 1957), ancient cratonic rocks (as investigated at Lac du Bonnet, Canada, Aspö, Sweden, and Vienne, France), and marine sedimentary rock formations (as studied at Mol, Belgium, and Bure, France). Additional multidisciplinary studies have been conducted at natural sites that bear characteristics analogous to potential repository systems, notably at natural uranium (and thorium) deposits including Poços de Caldas, Brazil, Alligator Rivers, Australia, Peña Blanca, Mexico, and Oklo, Gabon. Researchers of natural analogs for geologic disposal have addressed technical uncertainties regarding processes that have transpired over large time and space scales, which are generally inaccessible to laboratory studies. Principal questions for nuclear waste disposal include the geochemical stability and alteration rates of radionuclide bearing minerals and the mechanisms and rates of transport of radionuclides in groundwater. In their most direct applications, natural analogs studies have been devoted to testing specific models for repository performance and the experimental data that support those models. Parameters used in predictive performance assessment modeling have been compared to natural system data, including mineral solubilities, sorption coefficients, diffusion rates, and colloid transport properties. For example, the rate of uraninite oxidation and the natural paragenesis of uranium mineral alteration at Peña Blanca have been compared favorably to results of experimental studies of spent fuel alteration related to the proposed repository at Yucca Mountain, Nevada, USA. These results generally bracket repository conditions between natural and experimental systems providing confidence in the understanding of expected processes. Also, the conceptual bases and numerical techniques for modeling unsaturated zone contaminant transport over periods of thousands of years at Yucca Mountain were tested by modeling the observable record of metal transport from archaeological artifacts buried in Holocene tuff at Akrotiri, Greece. Geologically episodic mineral alteration and contaminant transport have been documented using radioisotope data in numerous analog systems providing insights for the interpretation and validity of predictive models for long term repository performance. The applicability and value of natural analog studies to understanding geologic disposal systems is a persistent question. As proposed disposal sites become increasingly well defined by site characterization and engineering design, the strengths and weaknesses of analogies can be assessed. Confidence in predictive models for complex geologic and engineered phenomena can be enhanced through multiple lines of investigation including studies of natural analog systems.

Murphy, W. M.

2009-12-01

426

Map Showing Geology, Oil and Gas Fields and Geologic Provinces of Africa, Ver. 2.0  

NSDL National Science Digital Library

The US Geological Survey offers the Map Showing Geology, Oil and Gas Fields and Geologic Provinces of Africa Web site and report. The agency's goal for the pieces includes assessing the undiscovered and technically recoverable oil and gas resources of the world. The site includes various descriptions of what the map depicts and how data was processed using Geographic Information Systems. Once the interactive map is activated, users can search and click the map of Africa to view geologic provinces, oil and gas fields, as well as the various surface geological classifications. Although the interface is a bit cumbersome and works best with a fast Internet connection, the unique information provided should draw the attention of those interested in geology. [JAB

Ahlbrandt, Thomas S.; Brownfield, M. E.; Charpentier, Ronald R.; Persits, F. M.; Takahashi, K. I.; Tuttle, M. L.

427

OneGeology-Europe - The Challenges and progress of implementing a basic geological infrastructure for Europe  

NASA Astrophysics Data System (ADS)

OneGeology-Europe is making geological spatial data held by the geological surveys of Europe more easily discoverable and accessible via the internet. This will provide a fundamental scientific layer to the European Plate Observation System Rich geological data assets exist in the geological survey of each individual EC Member State, but they are difficult to discover and are not interoperable. For those outside the geological surveys they are not easy to obtain, to understand or to use. Geological spatial data is essential to the prediction and mitigation of landslides, subsidence, earthquakes, flooding and pollution. These issues are global in nature and their profile has also been raised by the OneGeology global initiative for the International Year of Planet Earth 2008. Geology is also a key dataset in the EC INSPIRE Directive, where it is also fundamental to the themes of natural risk zones, energy and mineral resources. The OneGeology-Europe project is delivering a web-accessible, interoperable geological spatial dataset for the whole of Europe at the 1:1 million scale based on existing data held by the European geological surveys. Proof of concept will be applied to key areas at a higher resolution and some geological surveys will deliver their data at high resolution. An important role is developing a European specification for basic geological map data and making significant progress towards harmonising the dataset (an essential first step to addressing harmonisation at higher data resolutions). It is accelerating the development and deployment of a nascent international interchange standard for geological data - GeoSciML, which will enable the sharing and exchange of the data within and beyond the geological community within Europe and globally. The geological dataset for the whole of Europe is not a centralized database but a distributed system. Each geological survey implements and hosts an interoperable web service, delivering their national harmonized geological data. These datasets are registered in a multilingual catalogue, who is one the main part of this system. This catalogue and a common metadata profile allows the discovery of national geological and applied geological maps at all scapes, Such an architecture is facilitating re-use and addition of value by a wide spectrum of users in the public and private sector and identifying, documenting and disseminating strategies for the reduction of technical and business barriers to re-use. In identifying and raising awareness in the user and provider communities, it is moving geological knowledge closer to the end-user where it will have greater societal impact and ensure fuller exploitation of a key data resource gathered at huge public expense. The project is providing examples of best practice in the delivery of digital geological spatial data to users, e.g. in the insurance, property, engineering, planning, mineral resource and environmental sectors. The scientifically attributed map data of the project will provide a pan-European base for science research and, importantly, a prime geoscience dataset capable of integration with other data sets within and beyond the geoscience domain. This presentation will demonstrate the first results of this project and will indicate how OneGeology-Europe is ensuring that Europe may play a leading role in the development of a geoscience spatial data infrastructure (SDI) globally.

Asch, Kristine; Tellez-Arenas, Agnes

2010-05-01

428

Permeability alteration induced by drying of brines in porous media  

NASA Astrophysics Data System (ADS)

Permeability of reservoir rocks can be strongly altered by salt precipitation induced by drying. Indeed, gas injection in deep saline aquifers leads first to the brine displacement. The liquid saturation decreases near the injection point and reaches a residual water saturation. But at longer time, the water mass transfer to the gas phase by evaporation can become significant and the dissolved salt can precipitate in the porous structure. The solid salts fill the pores and the permeability decreases. Permeability alteration by salting out is a risk of injectivity decline in the context of CO2 geological storage in saline aquifers where high level of gas injection has to be maintained over decades. However, this problem has been poorly investigated. It implies physical processes that are strongly coupled: drying, water and gas flows in the porous structure and precipitation. This work is an experimental investigation aiming at measuring on natural rock samples the permeability alteration induced by convective drying where dry gas is injected through the sample. We show that alteration of permeability is strong and total blockage of the flow is even possible. We also show that the change in porosity due to the solid salt is heterogeneous along the rock samples. A local permeability-porosity relationship has been estimated from the measurements and we could deduce the permeability alteration function of time by modeling the drying dynamic. We show that it starts very early because capillary backflows are extremely efficient in this process to accumulate solid salt near the injection surfaces.

Peysson, Y.

2012-11-01

429

Geology Fieldnotes: Canyonlands National Park, Utah  

NSDL National Science Digital Library

This site contains park maps, visitor information, details about park geology, and a teacher feature (lessons for teaching science using National Park examples) for Canyonlands National Park in Utah. It discusses the creation of the canyons by the Green and Colorado rivers, as well as the geologic and human histories of the park. Also covered is information about the surrounding mountains (La Sals, Abajos, and Henry Mountains), the famous Upheaval Dome, The Maze, The Needles, and arches found within the park.

430

Tour of Park Geology: Colorado Plateau  

NSDL National Science Digital Library

This site provides links to geology fieldnotes about National Parks, Monuments, and Recreation Areas that are part of the Colorado Plateau. Each park site provides links to visitor information, photographs, park maps, multimedia resources, and teacher features (tools for teaching geology with National Park examples). Some of the areas linked to this site include: Dinosaur National Monument, Mesa Verde National Park, and Glen Canyon National Recreation Area.

431

Medical Geology in China: Then and Now  

Microsoft Academic Search

\\u000a The impact of the natural environment on human health has been a subject of study in China for at least 5,000 years. China’s\\u000a varied geology and geography and its large population living off the land have resulted in the presence of virtually every\\u000a known environmental health problem and some of the most serious medical geology problems. Fluorosis in China has

Zheng Baoshan; Wang Binbin; Robert B. Finkelman

432

Volcanic geology of Tyrrhena Patera, Mars  

NASA Astrophysics Data System (ADS)

Consideration is given to the geology of Tyrrhena Patera, a large low-relief volcano in the southern cratered highlands of Mars. The general geology of Tyrrhena Patera is outlined and models for the formation of the volcano are described. Models derived from studies of terrestrial pyroclastic flows are applied to deposits at Tyrrhena Patera, showing that the characteristics of the deposits are consistent with an origin by the emplacement of gravity-driven ash flows generated by hydromagmatic or magmatic explosive eruptions.

Greeley, R.; Crown, D. A.

1990-05-01

433

Global Bedrock Geology and River Chemistry  

Microsoft Academic Search

The lack of modern quantitative estimates of the Earth`s surface geology, one of the key parameters influencing river (and ocean) chemistry, is striking. Most published estimates of area-age relationships of sedimentary bedrock, for instance, were published before the 1980s, were based on less detailed geologic maps often decades older, and used techniques such as cutting and weighting age correlative map

B. Peucker-Ehrenbrink; M. W. Miller

2002-01-01

434

Geology of the Huntsville quadrangle, Alabama  

USGS Publications Warehouse

The 7 1/2-minute Huntsville quadrangle is in south-central Madison County, Ala., and includes part of the city of Hunstville. The south, north, east, and west boundaries of the quadrangle are about 3 miles north of the Tennessee River, 15 1/2 miles south of the Tennessee line, 8 miles west of the Jackson County line, and 9 miles east of the Limestone County line. The bedrock geology of the Huntsville quadrangle was mapped by the U.S. Geological Survey in cooperation with the city of Hunstville and the Geological Survey of Alabama as part of a detailed study of the geology and ground-water resources of Madison County, with special reference to the Huntsville area. G. T. Malmberg began the geologic mapping of the county in July 1953, and completed it in April 1954. T. H. Sanford, Jr., assisted Malmberg in the final phases of the county mapping, which included measuring geologic sections with hand level and steel tape. In November 1958 Sanford, assisted by L. R. West, checked contacts and elevations in the Hunstville quadrangle; made revisions in the contact lines; and wrote the text for this report. The fieldwork for this report was completed in April 1959.

Sanford, T. H., Jr.; Malmberg, G. T.; West, L. R.

1961-01-01

435

Field guide to hydrothermal alteration in the White River altered area and in the Osceola Mudflow, Washington  

USGS Publications Warehouse

The Cenozoic Cascades arcs of southwestern Washington are the product of long-lived, but discontinuous, magmatism beginning in the Eocene and continuing to the present (for example, Christiansen and Yeats, 1992). This magmatism is the result of subduction of oceanic crust beneath the North American continent. The magmatic rocks are divided into two subparallel, north-trending continental-margin arcs, the Eocene to Pliocene Western Cascades, and the Quaternary High Cascades, which overlies, and is east of, the Western Cascades. Both arcs are calc-alkaline and are characterized by voluminous mafic lava flows (mostly basalt to basaltic andesite compositions) and scattered large stratovolcanoes of mafic andesite to dacite compositions. Silicic volcanism is relatively uncommon. Quartz diorite to granite plutons are exposed in more deeply eroded parts of the Western Cascades Arc (for example, Mount Rainier area and just north of Mt. St. Helens). Hydrothermal alteration is widespread in both Tertiary and Quaternary igneous rocks of the Cascades arcs. Most alteration in the Tertiary Western Cascades Arc resulted from hydrothermal systems associated with small plutons, some of which formed porphyry copper and related deposits, including copper-rich breccia pipes, polymetallic veins, and epithermal gold-silver deposits. Hydrothermal alteration also is present on many Quaternary stratovolcanoes of the High Cascades Arc. On some High Cascades volcanoes, this alteration resulted in severely weakened volcanic edifices that were susceptible to failure and catastrophic landslides. Most notable is the sector collapse of the northeast side of Mount Rainier that occurred about 5,600 yr. B.P. This collapse resulted in formation of the clay-rich Osceola Mudflow that traveled 120 km down valley from Mount Rainier to Puget Sound covering more than 200 km2. This field trip examines several styles and features of hydrothermal alteration related to Cenozoic magmatism in the Cascades arcs. The morning of the trip will examine the White River altered area, which includes high-level alteration related to a large, early Miocene magmatic-hydrothermal system exposed about 10 km east of Enumclaw, Washington. Here, vuggy silica alteration is being quarried for silica and advanced argillic alteration has been prospected for alunite. Clay-filled fractures and sulfide-rich, fine-grained sedimentary rocks of hydrothermal origin locally are enriched in precious metals. Many hydrothermal features common in high-sulfidation gold-silver deposits and in advanced argillic alteration zones overlying porphyry copper deposits (for example, Gustafson and Hunt, 1975; Hedenquist and others, 2000; Sillitoe, 2000) are exposed, although no economic base or precious metal mineralized rock has been discovered to date. The afternoon will be spent examining two exposures of the Osceola Mudflow along the White River. The Osceola Mudflow contains abundant clasts of altered Quaternary rocks from Mount Rainier that show various types of hydrothermal alteration and hydrothermal features. The mudflow matrix contains abundant hydrothermal clay minerals that added cohesiveness to the debris flow and helped allow it to travel much farther down valley than other, noncohesive debris flows from Mount Rainier (Crandell, 1971; Vallance and Scott, 1997). The White River altered area is the subject of ongoing studies by geoscientists from Weyerhaeuser Company and the U.S. Geological Survey (USGS). The generalized descriptions of the geology, geophysics, alteration, and mineralization presented here represent the preliminary results of this study (Ashley and others, 2003). Additional field, geochemical, geochronologic, and geophysical studies are underway. The Osceola Mudflow and other Holocene debris flows from Mount Rainier also are the subject of ongoing studies by the USGS (for example, Breit and others, 2003; John and others, 2003; Plumlee and others, 2003, Sisson and others, 2003; Vallance and others, 2003). Studies of hydrothermal alteration in the Osceola Mudflow are being used to bett

John, David A.; Rytuba, James J.; Ashley, Roger P.; Blakely, Richard J.; Vallance, James W.; Newport, Grant R.; Heinemeyer, Gary R.

2003-01-01

436

Geologic studies in Alaska by the U.S. Geological Survey during 1985  

USGS Publications Warehouse

This circular contains short reports about many of the geologic studies carried out in Alaska by the U.S. Geological Survey and cooperating agencies in 1985. The topics cover a wide range in scientific and economic interest. Separate bibliographic listings of published reports are included. These listings are: (1) data releases and folio components derived from the Alaska Mineral Resource Assessment Program, (2) reports on Alaska released in U.S. Geological Survey publications in 1985, and (3) reports about Alaska by U.S. Geological Survey authors in various scientific journals in 1985.

Edited by Bartsch-Winkler, S.; Reed, K. M.

1986-01-01

437

OneGeology-Europe Plus Initiative  

NASA Astrophysics Data System (ADS)

The Geological Surveys of the European countries hold valuable resources of geological data but, to discover, understand and use this data efficiently, a good level of standardization is essential. The OneGeology-Europe project had the aim of making geological maps at a scale 1:1M from Europe discoverable and accessible, available under a common data license and described by multilingual metainformation. A harmonized specification for basic geological map data was developed so that significant progress towards harmonizing the datasets was achieved. Responsibility for the management of the OneGeology-Europe portal has been taken by EuroGeoSurveys and provided by CGS and BRGM. Of the 34 members of EuroGeoSurveys (EGS), only 20 participated in the OneGeology-Europe project (Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Ireland, Italy, Luxembourg, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Sweden, Spain, United Kingdom), so the European area was not completely covered. At the 33rd General Meeting and Directors Workshop in 2012 it was therefore decided to establish a successor initiative OneGeology Europe Plus (1G-E+) with the purpose of extending the coverage by geological maps at a scale of 1:1 M to all the EGS member countries (including Albania, Austria, Bulgaria, Croatia, Cyprus, Greece, Iceland, Lithuania, Malta, Romania, Russia, Switzerland, Turkey, Ukraine) and also, if possible, to the other European countries (Belorussia, Bosnia and Herzegovina, Faeroe Islands, Kosovo, Latvia, Macedonia, Moldavia, Montenegro, Serbia). In order to achieve the desired result, it has been necessary for the new GSOs who intend to supply the additional 1G-E standardized services to carry out the work using their own staff and resources. The technical guidance and other support have been provided by the 1G-E+ Technical Support Team, funded from the internal budgets of their respective surveys. The team is coordinated by the Czech Geological Survey (CGS) working with the Bureau de Recherches Géologiques et Minières (BRGM), the British Geological Survey (BGS), the Geological Survey of Denmark and Greenland (GEUS) and the Geological Survey of Slovenia (GeoZS). The Geological Survey of the Netherlands (TNO) decided to provide financial support for the initiative. The Technical Support Team has been providing the technical advice required to enable the inclusion of geological maps from new countries in the 1G-E Portal using the standards developed and accepted for 1G-E. Cookbooks, on-line help and a helpdesk are provided during the work. A technical workshop was organized at which all the technical steps required to reach the target solution were presented and discussed. All newcomers must agree the existing common license that was created for downloading the 1G-E data. It should be emphasized that the results will be displayed as part of the 1G-E project and metadata/portal infrastructures. The process is still ongoing because the harmonization work for most of the countries involved has been a demanding process. Some countries are facing difficulties because of the lack of expert personnel or insufficient resources of data. Despite some problems, the 1G-E+ initiative and the work involved has contributed to effective networking and technical cooperation between the GSOs across the wider European region.

Capova, Dana; Kondrova, Lucie

2014-05-01

438

Geologic Mapping of Mawrth Vallis and Nili Fossae, Mars  

NASA Astrophysics Data System (ADS)

Mapping studies using traditional photogeologic and modern digital geologic mapping techniques of Mawrth Vallis (six MTM quads; 17.5-27.5N, 335-350E) and Nili Fossae (six MTM quads; 17.5-32.5N, 070-080E) at 1:1M-scale are being used to assess geologic materials and processes that shape the highlands along the Arabia Terra dichotomy boundary. Placing these landscapes, their material units, structural features, and unique compositional outcrops into broad spatial and temporal context may help to constrain: a) paleo-environments and climate conditions through time, b) fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and c) the influences of nearby volcanic and tectonic features on hydrologic systems and processes, including possible hydrothermal alteration, across the region. Since the initial discovery of phyllosilicate-bearing materials by the OMEGA instrument (Poulet et al., 2005; Bibring et al., 2006], Mawrth Vallis and Nili Fossae have become areas of intense scrutiny by high-resolution cameras and spectrometers. The mineralogic diversity (a variety of clays, unaltered ferromagnesian silicates, sulfates, and small detections of carbonate) is unprecedented on the surface of Mars and requires stratigraphic sequencing to unlock their complex histories. Mapping to date has delineated 12 geologic units for Mawrth Vallis and 17 for Nili Fossae. Mawrth Vallis units include: Acidalia Planitia; Arabia Terra, members 1&2; Mawrth Vallis channel; Mawrth Vallis plains, members 1-4; and several crater facies. Nili Fossae units are: Arabia Terra plateau sequence, members 1-5, Arabia Plateau etched, members a-c; Borealis plains; Isisdis plains, members 1-3, Syrtis Major flows, members 1,2a,&2b, crater facies, and surficial deposits. It is our hope that the small-scale mapping being performed herein may provide regional context for larger-scale and more focused studies (e.g., MSL landing site surveys) investigating the distribution, stratigraphic position, and potential lateral continuity of compositionally distinct outcrops as identified by instruments in orbit. Geologic Map of Nili Fossae. Updated maps of Nili Fossae and Mawrth Vallis will be presented and available for digital distribution.

Bleamaster, L. F.; Chuang, F.

2010-12-01

439

Geologic reconnaissance in western Liberia  

USGS Publications Warehouse

Irazu volcano, a large composite cone, consists of interbedded lava flows, lahars, and ash beds. This rock sequence, named the Irazu Group, has been divided into four formations; from the base: Reventado Formation, Sapper Formation, Birris Formation, and Cervantes Formation. Only the Reventado and Sapper Formations crop out in the Reventado watershed. The Reventado Formation consists of at least four widespread medium-gray finely porphyritic lava flows and interbedded lahar and some ash. Where not excessively jointed, lava flows within the formation are structurally sound and generally fresh. The Sapper Formation also consists of interbedded lava, lahar, and ash; lavas are black dense and coarsely porphyritic and in the middle part of the watershed are structurally sound if not excessively jointed. In the upper part of the watershed Sapper lavas are deeply altered, pyritic and structurally unsound. At least three major inactive and six major active landslides have been recognized In the Reventado watershed, all apparently in the Sapper Formation. Mudflows in the Reventado watershed have been supplied with debris from the caving of oversteepened stream banks and to a lesser extent from the active landslides.

Leo, G. W.; White, R. W.

1967-01-01

440

Role of geology in diamond project development  

NASA Astrophysics Data System (ADS)

For a mining operation to be successful, it is important to bring fundamental and applied science together. The mining engineer needs to understand the importance of geology, mineralogy and petrography, and how projects can benefit from the data collected during the exploration and pre-exploration stage. Geological scientists also need to understand the process of project development from the exploration stage through mine design and operation to mine closure. Kimberlite pipe or dyke emplacement, geology and petrology/mineralogy are three areas that illustrate how information obtained from the geological studies could directly influence the mining method selection and the project strategy and design. Kimberlite emplacement is one of the fundamental processes that rely on knowledge of the kimberlite body geology. Although the importance of the emplacement model is commonly recognized in the resource geology, mining engineers do not always appreciate its importance to the mine design. The knowledge of the orebody geometry, character of the contact zones, internal structures and distribution of inclusions could directly influence pit wall stability (thus strip ratio), underground mining method selection, dilution, treatability, and the dewatering strategy. Understanding the internal kimberlite geology mainly includes the geometry and character of individual phases, and the orientation and character of internal structures that transect the rock mass. For any mining method it is important to know "where the less and where the more competent rocks are located" to achieve stability. On the other hand, the detailed facies studies may not be important for the resource and mine design if the rock types have similar physical properties and diamond content. A good understanding of the kimberlite petrology and mineralogy could be crucial not only to the treatability (namely diamond damage and liberation), but also to the pit wall and underground excavation stability, support design, mine safety (mudrush risk assessment) and mine dewatering. There is no doubt that a better understanding of the kimberlite and country rock geology has a direct impact on the safety and economics of the mining operations. The process of mine design can start at the beginning of kimberlite discovery by incorporating the critical geological information without necessarily increasing the exploration budget. It is important to appreciate the usefulness of fundamental geological research and its impact on increased confidence in the mine design. Such studies should be viewed as worthwhile investments, not as cost items.

Jakubec, Jaroslav

2004-09-01

441

Geology, mineralogy, and physical properties of Minnesota kaolins  

SciTech Connect

Both primary and secondary kaolins are mined along the Minnesota River near the town of Redwood Falls. The primary kaolins are the result of alteration by weathering of precambrian gneisses and granites. The secondary kaolins are small sedimentary deposits that are deltaic in origin. The primary kaolins are generally thick of the order of 30 meters or more and are covered by thick glacial materials ranging from 15 to 30 meters. These primary kaolins vary in mineralogy from top to bottom reflecting the weathering alteration intensity. The secondary kaolins are relatively thin averaging about 5 meters thick and have been transported only short distances from their source. The minerals present in these kaolins are kaolinite, chlorite, halloysite, smectite, quartz, feldspars, and micas. At present the kaolins are used as a raw material for brick and cement. Some of the kaolins can be beneficiated by using wet process techniques so that potentially they could be used as a filled for paper, paint, plastics, etc. The economic geology and mining potential of these kaolins will be reviewed.

Murray, H.H. (Indiana Univ., Bloomington, IN (United States). Dept. of Geological Sciences)

1993-03-01

442

Optimization geological sequestration of CO2 by capillary trapping mechanisms  

NASA Astrophysics Data System (ADS)

Geological carbon sequestration, as a method of atmospheric greenhouse gas reduction, is at the technological forefront of the climate change movement. Sequestration is achieved by capturing carbon dioxide (CO2) gas effluent from coal fired power plants and injecting it into saline aquifers. In an effort to fully understand and optimize CO2 trapping efficiency, the capillary trapping mechanisms that immobilize subsurface CO2 were analyzed at the pore scale. Pairs of analogous fluids representing the range of in situ supercritical CO2 and brine conditions were used during experimentation. The two fluids (identified as wetting and non wetting) were imbibed and drained from a flow cell apparatus containing a sintered glass bead column. Experimental and fluid parameters, such as interfacial tension, non-wetting fluid viscosity, and flow rate, were altered to characterize their impact on capillary trapping. Through the use of computed x-ray microtomography (CMT), we were able to quantify distinct differences between initial (post NW phase imbibition) and residual (post wetting fluid flood) non-wetting phase saturations. Alterations to the viscosity of the non-wetting and wetting fluid phases were made during experimentation; results indicate that the viscosity of the non-wetting fluid is the parameter of interest as residual saturations increased with increasing viscosity. These observed trends will be used to identify optimal conditions for trapping CO2 during subsurface sequestration.

Wildenschild, D.; Harper, E.; Herring, A. L.; Armstrong, R. T.

2012-12-01

443

Genetic Alterations in Glioma  

PubMed Central

Gliomas are the most common type of primary brain tumor and have a dismal prognosis. Understanding the genetic alterations that drive glioma formation and progression may help improve patient prognosis by identification of novel treatment targets. Recently, two major studies have performed in-depth mutation analysis of glioblastomas (the most common and aggressive subtype of glioma). This systematic approach revealed three major pathways that are affected in glioblastomas: The receptor tyrosine kinase signaling pathway, the TP53 pathway and the pRB pathway. Apart from frequent mutations in the IDH1/2 gene, much less is known about the causal genetic changes of grade II and III (anaplastic) gliomas. Exceptions include TP53 mutations and fusion genes involving the BRAF gene in astrocytic and pilocytic glioma subtypes, respectively. In this review, we provide an update on all common events involved in the initiation and/or progression across the different subtypes of glioma and provide future directions for research into the genetic changes.

Bralten, Linda B. C.; French, Pim J.

2011-01-01

444

Oregon geology - parent of the soil, foundation for the vine  

USGS Publications Warehouse

This presentation describes USGS geologic mapping in western Oregon, geologic map products, a thumbnail sketch of geologic history, a discussion of new mapping in progress in northwest Oregon, a tour of northwest Oregon geologic units, their relation to new American Viticultural Areas, and online sources of information.

Wells, Ray

2006-01-01

445

Geology Fieldnotes: Lake Mead National Recreation Area, Nevada/Arizona  

NSDL National Science Digital Library

This Lake Mead National Recreation Area site contains park geology information, maps, photographs, visitor information, and teacher features (resources for teaching geology using national park examples). Park Geology is a guided tutorial, covering two billion years of geologic time from the Precambrian through the Cenozoic.

446

The NASA\\/USGS Planetary Geologic Mapping Program  

Microsoft Academic Search

NASA's Planetary Geologic Mapping Program (PGM) publishes geologic maps of the planets based on released, geodetically controlled spacecraft data. The general objectives of PGM include (1) production of geologic maps that will greatly increase our knowledge of the materials and processes that have contributed to the evolution of Solar System bodies, and (2) geologic surveys of areas of special interest

K. Tanaka

2006-01-01

447

Turning Geological Data into Reliable Mineral Resource Estimates1  

Microsoft Academic Search

This paper deals with the building of geological interpretations from necessarily limited geological data and the use of such interpretations in the estimation of mineral resources. Since geological interpretations are a type of scientific model, the process of constructing such models in terms of the objectives and mechanics involved is briefly reviewed. Particular aspects of geological interpretations relevant to resource

John Vann

448

Geology Fieldnotes: Death Valley National Park, California/Nevada  

NSDL National Science Digital Library

This Death Valley National Park site contains park geology information, park maps, photographs, visitor information, and teacher features (resources for teaching geology using National Park examples). The Park Geology section contains an exaggerated cross-section showing the vertical rise within Death Valley. A link is provided to Death Valley's expanded geology page.

449

Geological hazards risk regionalization based on GIS in Chongzhou city  

Microsoft Academic Search

After Wenchuan Earthquake on May 12, 2008, various geological hazards happened frequently in Chongzhou city, Sichuan.This paper analyzes factors inducing hazards by weighted comprehensive evaluation (WCE) and analytic hierarchy process (AHP), and builds the geological hazards assessment model.On the basis, the map of geological hazards lability zoning is drew. The study shows that geological hazards in Chongzhou city are mainly

Chengqiang Shu; Liangqun Jiang

2011-01-01

450

ALTERATION OF U(VI)-PHASES UNDER OXIDIZING CONDITIONS  

SciTech Connect

Uranium-(VI) phases are the primary alteration products of the UO{sub 2} in spent nuclear fuel and the UO{sub 2+x}, in natural uranium deposits. The U(VI)-phases generally form sheet structures of edge-sharing UO{sub 2}{sup 2+} polyhedra. The complexity of these structures offers numerous possibilities for coupled-substitutions of trace metals and radionuclides. The incorporation of radionuclides into U(VI)-structures provides a potential barrier to their release and transport in a geologic repository that experiences oxidizing conditions. In this study, we have used natural samples of UO{sub 2+x}, to study the U(VI)-phases that form during alteration and to determine the fate of the associated trace elements.

A.P. Deditius; S. Utsunomiya; R.C. Ewing

2006-02-21

451

GeoKansas: A Place to Learn About Kansas Geology  

NSDL National Science Digital Library

This website, part of the Kansas Geological Survey (KGS), contains educational information about Kansas geology, including images of geology from around the state, details about field trips, and a glossary with hundreds of geologic terms and various geologic places of interest sorted by region. Kansas Rocks describes various rocks by name and where they are found and Kansas Fossils describes fossil types and locations. Geo Topics describes various issues and subjects relating to state geology such as the age of the Earth, geologic time, rock nomenclature, an ID table for Kansas minerals with Mohs hardness scale, and coal, lead and zinc mining within the state.

Brosius, Liz

452

Acid alteration in the fumarolic environment of Usu volcano, Hokkaido, Japan  

NASA Astrophysics Data System (ADS)

The last eruptive activity of Usu volcano in 1977-78 involved the development of high temperature (550-710°C) fumaroles. The gases emitted were H 2O-rich (95-99 mol%) with Cl/S=0.05-0.9, F/Cl=0.3-0.2 and with RH=-2.5 close to the rock buffer (FeO/FeO 1.5). Cooling and oxidation of the high temperature gases resulted in the formation of acidic condensates (pH=1.6) that interacted with the wall rock. Complete leaching of the cations (Ca, Na, Mg, Al and Fe) from the primary minerals and matrix glass occurred leaving in place only silica. These mobilized cations precipitated as secondary minerals from acidic fluids that circulated in microcracks. SEM study shows mineral associations reflecting increasing fluid oxidation: (a) Al fluorides such as ralstonite (NaMgAlF 6·H 2O), pyrite, and anhydrite/gypsum; (b) an Al hydroxide, hematite, gypsum and amorphous silica or cristobalite; (c) Al sulfates such as hydronium alunite [(H 3O)Al 3(SO 4) 2(OH) 6], alunite [KAl 3(SO 4) 2(OH) 6], amorphous silica, cristobalite, hematite and anhydrite/gypsum; (d) Al sulfates, Al fluorides, amorphous silica, cristobalite, pyrite and anhydrite/gypsum. A Ti oxide, a Fe-Mg sulfate and barite are present in minor amounts. Clay minerals are absent from the observed assemblages. Primary phenocrysts and matrix glass undergo a complete transformation to silica enriched in fluorine (1-7 wt%). This fluorine enrichment in the silicified parts of silicates and in silica incrustations suggests that F may play a role in silica mobilization. Modeling of the cooling of the high-temperature gases was performed with the program GASWORKS. The calculations suggest that 66% of the total sulfur from the gases may be lost by deposition as native sulfur at temperatures below 160°C. Thermochemical modeling of condensate-rock interaction using CHILLER indicates that the cooling of gases was the source of the altering solutions. Oxidation, by atmospheric O 2, of the sulfur-reduced species in the volcanic gas condensates resulted in their extreme acidification. Condensate-rock interactions produce supersaturation with respect to the following mineral assemblages at 95°C: (1) pyr