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Sample records for geology wall-rock alteration

  1. Sulphide mineralization and wall-rock alteration in ophiolites and modern oceanic spreading centres

    USGS Publications Warehouse

    Koski, R.A.

    1983-01-01

    Massive and stockwork Fe-Cu-Zn (Cyprus type) sulphide deposits in the upper parts of ophiolite complexes represent hydrothermal mineralization at ancient accretionary plate boundaries. These deposits are probable metallogenic analogues of the polymetallic sulphide deposits recently discovered along modern oceanic spreading centres. Genetic models for these deposits suggest that mineralization results from large-scale circulation of sea-water through basaltic basement along the tectonically active axis of spreading, a zone of high heat flow. The high geothermal gradient above 1 to 2 km deep magma chambers emplaced below the ridge axis drives the convective circulation cell. Cold oxidizing sea-water penetrating the crust on the ridge flanks becomes heated and evolves into a highly reduced somewhat acidic hydrothermal solvent during interaction with basaltic wall-rock. Depending on the temperature and water/rock ratio, this fluid is capable of leaching and transporting iron, manganese, and base metals; dissolved sea-water sulphate is reduced to sulphide. At the ridge axis, the buoyant hydrothermal fluid rises through permeable wall-rocks, and fluid flow may be focussed along deep-seated fractures related to extensional tectonic processes. Metal sulphides are precipitated along channelways as the ascending fluid undergoes adiabatic expansion and then further cooling during mixing with ambient sub-sea-floor water. Vigorous fluid flow results in venting of reduced fluid at the sea-floor/sea-water interface and deposition of massive sulphide. A comparison of sulphide mineralization and wall-rock alteration in ancient and modern spreading centre environments supports this genetic concept. Massive sulphide deposits in ophiolites generally occur in clusters of closely spaced (< 1-5 km) deposits. Individual deposits are a composite of syngenetic massive sulphide and underlying epigenetic stockwork-vein mineralization. The massive sulphide occurs as concordant tabular

  2. Application of kinematic vorticity and gold mineralization for the wall rock alterations of shear zone at Dungash gold mining, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Kassem, Osama M. K.; Abd El Rahim, Said H.; El Nashar, EL Said R.; AL Kahtany, Kaled M.

    2016-11-01

    The use of porphyroclasts rotating in a flowing matrix to estimate mean kinematic vorticity number (Wm) is important for quantifying the relative contributions of pure and simple shear in wall rocks alterations of shear zone at Dungash gold mine. Furthermore, it shows the relationship between the gold mineralization and deformation and also detects the orientation of rigid objects during progressive deformation. The Dungash gold mine area is situated in an EW-trending quartz vein along a shear zone in metavolcanic and metasedimentary host rocks in the Eastern Desert of Egypt. These rocks are associated with the major geologic structures which are attributed to various deformational stages of the Neoproterozoic basement rocks. We conclude that finite strain in the deformed rocks is of the same order of magnitude for all units of metavolcano-sedimentary rocks. The kinematic vorticity number for the metavolcanic and metasedimentary samples in the Dungash area range from 0.80 to 0.92, and together with the strain data suggest deviations from simple shear. It is concluded that nappe stacking occurred early during the underthrusting event probably by brittle imbrication and that ductile strain was superimposed on the nappe structure during thrusting. Furthermore, we conclude that disseminated mineralization, chloritization, carbonatization and silicification of the wall rocks are associated with fluids migrating along shearing, fracturing and foliation of the metamorphosed wall rocks.

  3. Building the 3D Geological Model of Wall Rock of Salt Caverns Based on Integration Method of Multi-source data

    NASA Astrophysics Data System (ADS)

    Yongzhi, WANG; hui, WANG; Lixia, LIAO; Dongsen, LI

    2017-02-01

    In order to analyse the geological characteristics of salt rock and stability of salt caverns, rough three-dimensional (3D) models of salt rock stratum and the 3D models of salt caverns on study areas are built by 3D GIS spatial modeling technique. During implementing, multi-source data, such as basic geographic data, DEM, geological plane map, geological section map, engineering geological data, and sonar data are used. In this study, the 3D spatial analyzing and calculation methods, such as 3D GIS intersection detection method in three-dimensional space, Boolean operations between three-dimensional space entities, three-dimensional space grid discretization, are used to build 3D models on wall rock of salt caverns. Our methods can provide effective calculation models for numerical simulation and analysis of the creep characteristics of wall rock in salt caverns.

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

    SciTech Connect

    Galbreath, K.C.; Duke, E.F.; Papike, J.J. ); Laul, J.C. )

    1988-07-01

    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.

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

    USGS Publications Warehouse

    Getahun, A.; Reed, M.H.; Symonds, R.

    1996-01-01

    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 (FeCl3) 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

  6. Wall-Rock alteration of biotite hornfels at the Tyrnyauz deposit, Russia

    NASA Astrophysics Data System (ADS)

    Gramenitskiy, E. N.

    2016-09-01

    A new zonation type of W-Mo-bearing altered biotite hornfels at the Tyrnyauz deposit is reported. The review of zonation indicates a subsequent transition into the mobile state of CaO, MgO, FeO, and Al2O3 and retention of volume owing to dissolution or deposition of quartz as an excess mobile mineral. The main features of zonation are similar to those in acid leaching columns; the input of strong CaO base into the outer zone is unusual.

  7. Fragmentation of wall rock garnets during deep crustal earthquakes

    PubMed Central

    Austrheim, Håkon; Dunkel, Kristina G.; Plümper, Oliver; Ildefonse, Benoit; Liu, Yang; Jamtveit, Bjørn

    2017-01-01

    Fractures and faults riddle the Earth’s crust on all scales, and the deformation associated with them is presumed to have had significant effects on its petrological and structural evolution. However, despite the abundance of directly observable earthquake activity, unequivocal evidence for seismic slip rates along ancient faults is rare and usually related to frictional melting and the formation of pseudotachylites. We report novel microstructures from garnet crystals in the immediate vicinity of seismic slip planes that transected lower crustal granulites during intermediate-depth earthquakes in the Bergen Arcs area, western Norway, some 420 million years ago. Seismic loading caused massive dislocation formations and fragmentation of wall rock garnets. Microfracturing and the injection of sulfide melts occurred during an early stage of loading. Subsequent dilation caused pervasive transport of fluids into the garnets along a network of microfractures, dislocations, and subgrain and grain boundaries, leading to the growth of abundant mineral inclusions inside the fragmented garnets. Recrystallization by grain boundary migration closed most of the pores and fractures generated by the seismic event. This wall rock alteration represents the initial stages of an earthquake-triggered metamorphic transformation process that ultimately led to reworking of the lower crust on a regional scale. PMID:28261660

  8. Fragmentation of wall rock garnets during deep crustal earthquakes.

    PubMed

    Austrheim, Håkon; Dunkel, Kristina G; Plümper, Oliver; Ildefonse, Benoit; Liu, Yang; Jamtveit, Bjørn

    2017-02-01

    Fractures and faults riddle the Earth's crust on all scales, and the deformation associated with them is presumed to have had significant effects on its petrological and structural evolution. However, despite the abundance of directly observable earthquake activity, unequivocal evidence for seismic slip rates along ancient faults is rare and usually related to frictional melting and the formation of pseudotachylites. We report novel microstructures from garnet crystals in the immediate vicinity of seismic slip planes that transected lower crustal granulites during intermediate-depth earthquakes in the Bergen Arcs area, western Norway, some 420 million years ago. Seismic loading caused massive dislocation formations and fragmentation of wall rock garnets. Microfracturing and the injection of sulfide melts occurred during an early stage of loading. Subsequent dilation caused pervasive transport of fluids into the garnets along a network of microfractures, dislocations, and subgrain and grain boundaries, leading to the growth of abundant mineral inclusions inside the fragmented garnets. Recrystallization by grain boundary migration closed most of the pores and fractures generated by the seismic event. This wall rock alteration represents the initial stages of an earthquake-triggered metamorphic transformation process that ultimately led to reworking of the lower crust on a regional scale.

  9. 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

    Böhlke, J.K.

    1989-01-01

    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

  10. A mechanism for high wall-rock velocities in rockbursts

    USGS Publications Warehouse

    McGarr, A.

    1997-01-01

    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.

  11. Aqueous alteration of VHTR fuels particles under simulated geological conditions

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  12. Kimberlite Wall Rock Fragmentation: Venetia K08 Pipe Development

    NASA Astrophysics Data System (ADS)

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

    2009-05-01

    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

  13. Constraints on magma-wall rock thermal interaction during explosive eruptions from textural analysis of cored bombs

    NASA Astrophysics Data System (ADS)

    Sottili, G.; Taddeucci, J.; Palladino, D. M.

    2010-04-01

    Cored bombs, a kind of pyroclast consisting of a lithic core surrounded by a chilled shell of juvenile material, record the thermal interaction of magma with wall rocks. We performed textural analysis of cored bombs, solid-melt heat-transfer theoretical modelling, and high-temperature coating experiments to put temporal and intensity constraints on the thermal interaction of potassic magma feeder systems with carbonate wall rocks during explosive eruptions in the Quaternary, Colli Albani Volcanic District (Roman Province). It appears that the degree of thermal alteration of lithic cores records the duration of magma-core heat transfer, whereas the core/shell size ratio records the initial entrainment temperature of the lithic fragment. Both parameters appear to vary significantly with the eruptive style, magnitude and vent location. Specifically, small-scale (~ 0.1-1 km 3 DRE) hydromagmatic eruptions show magma-core heat-transfer durations of 0.1-10 s and entrainment temperatures in the range of 100-300 °C in the case of a monogenetic maar located in the Colli Albani peripheral area, while entrainment temperature is as high as to 800 °C for a polygenetic maar in a high-enthalpy geothermal system at the margins of the main Colli Albani magma chamber. A large-scale (~ 30 km 3 DRE) caldera-forming explosive event shows magma-core heat-transfer duration in the order of 10 2-10 3 s and temperature of 100-500 °C at the initial magma-wall rock contact. On these grounds, we derived the cooling rate of magmas as a function of the initial temperature, mass and size distribution of lithic clasts entrained. Magma cooling by lithic entrainment may have occurred on the same time-scale as that of eruptive pulses (seconds to hours), implying that lithic entrainment may effect changes in magma physico-chemical properties on a short time-scale and, consequently, affect eruptive conduit dynamics.

  14. Geology, alteration, age, and origin of iron oxide-apatite deposits in Upper Eocene quartz monzonite, Zanjan district, NW Iran

    NASA Astrophysics Data System (ADS)

    Nabatian, Ghasem; Ghaderi, Majid; Corfu, Fernando; Neubauer, Franz; Bernroider, Manfred; Prokofiev, Vsevolod; Honarmand, Maryam

    2014-02-01

    Iron oxide-apatite deposits are present in Upper Eocene pyroxene-quartz monzonitic rocks of the Zanjan district, northwestern Iran. Mineralization occurred in five stages: (1) deposition of disseminated magnetite and apatite in the host rock; (2) mineralization of massive and banded magnetite ores in veins and stockwork associated with minor brecciation and calcic alteration of host rocks; (3) deposition of sulfide ores together with potassic alteration; (4) formation of quartz and carbonate veins and sericite, chlorite, epidote, silica, carbonate, and tourmaline alteration; and (5) supergene alteration and weathering. U-Pb dating of monazite inclusions in the apatite indicates an age of 39.99 ± 0.24 Ma, which is nearly coeval with the time of emplacement of the host quartz monzonite, supporting the genetic connection. Fluid inclusions in the apatite have homogenization temperatures of about 300 °C and oxygen isotopic compositions of the magnetite support precipitation from magmatic fluids. Late-stage quartz resulted from the introduction of a cooler, less saline, and isotopically depleted fluid. The iron oxide-apatite deposits in the Tarom area of the Zanjan district are typical of a magmatic-hydrothermal origin and are similar to the Kiruna-type deposits with respect to mineral assemblages, fabric and structure of the iron ores, occurrence of the ore bodies, and wall rock alteration.

  15. Global geologic context for rock types and surface alteration on Mars

    USGS Publications Warehouse

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

    2004-01-01

    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.

  16. Non-Darcian flow experiments of shear-thinning fluids through rough-walled rock fractures

    NASA Astrophysics Data System (ADS)

    Rodríguez de Castro, Antonio; Radilla, Giovanni

    2016-11-01

    Understanding non-Darcian flow of shear-thinning fluids through rough-walled rock fractures is of vital importance in a number of industrial applications such as hydrogeology or petroleum engineering. Different laws are available to express the deviations from linear Darcy law due to inertial pressure losses. In particular, Darcy's law is often extended through addition of quadratic and cubic terms weighted by two inertial coefficients depending on the strength of the inertia regime. The relations between the effective shear viscosity of the fluid and the apparent viscosity in porous media when inertial deviations are negligible were extensively studied in the past. However, only recent numerical works have investigated the superposition of both inertial and shear-thinning effects, finding that the same inertial coefficients obtained for non-Darcian Newtonian flow applied in the case of shear-thinning fluids. The objective of this work is to experimentally validate these results, extending their applicability to the case of rough-walled rock fractures. To do so, flow experiments with aqueous polymer solutions have been conducted using replicas of natural fractures, and the effects of polymer concentration, which determine the shear rheology of the injected fluid, have been evaluated. Our findings show that the experimental pressure loss-flow rate data for inertial flow of shear-thinning fluids can be successfully predicted from the empirical parameters obtained during non-Darcian Newtonian flow and Darcian shear-thinning flow in a given porous medium.

  17. Layering in the wall rock of Valles Marineris: intrusive and extrusive magmatism

    NASA Astrophysics Data System (ADS)

    Williams, Jean-Pierre; Paige, David A.; Manning, Craig E.

    2003-06-01

    High-resolution images of the walls exposed in Valles Marineris reveal variations in appearance and degree of layering indicating various lithologies comprise the Tharsis plateau. The layered wall rock has been proposed to result from effusive flood basalt volcanism or interbedded sediments and volcanics. We present observations of unlayered rock that indicate layering extends to a greater depth in the western half of Valles Marineris and is confined to the Tharsis plateau, a region of thickened, uplifted crust resulting from prolonged intrusive activity. Consistent with this view, we propose that the observed layering may be a manifestation of intrusive rocks resulting from crystal fractionation of intruded basaltic magmas. Terrestrial layered plutons provide analogs for comparison such as those of the North Atlantic Igneous Province (NAIP) a large igneous province associated with crustal rifting and exposures of thick sequences of layered flood basalts and intruded layered cumulates.

  18. Origin of saline, neutral-pH, reduced epithermal waters by reaction of acidic magmatic gas condensates with wall rock

    SciTech Connect

    Reed, M.H. . Dept. of Geological Sciences)

    1993-04-01

    Fluid inclusions in quartz and sphalerite of epithermal veins containing galena, sphalerite and chalcopyrite with silver sulfides and electrum commonly have salinities of 2 to 10 weight percent NaCl equivalent. Examples include Bohemia, OR, Comstock, NV, and Creede, CO. Salinities in such base metal-rich systems are apparently greater than those in gold-adularia, base metal-poor systems such as Sleeper, NV, Republic, WA, and Hishikare, Kyushu. Saline epithermal fluids are commonly assumed to have been derived from saline magmatic brines, from local host formations, as has been suggested for Creede, or from evaporative concentration (boiling) of more dilute meteoric ground water. Another possibility, which may be the most common origin, is reaction of wall rocks with magmatic gas condensates rich in HCl and sulfuric acid. A mixture of one part Augustine Volcanic gas condensate in 10 parts cold ground water has a pH of 0.7 and the dominant cation is H[sup +] by a factor of 10[sup 4]. Calculated reaction of this condensate mixture with andesite at 300 C to a water/rock ratio (w/r) of 4.6 yields an NaCl-dominated fluid with a total salinity of 2.1 wt %. and pH 3.7. Further reaction, to w/r 0.14 yields a fluid salinity of 2.6 wt % and pH of 5.7; this fluid is in equilibrium with a propylitic alteration assemblage. Aqueous sulfide accumulates during the rock reaction as sulfate is reduced to sulfide when ferrous iron is oxidized to ferric iron. Sulfide concentration in the latter fluid is 32 ppm, far exceeding sulfate concentration. In the overall reaction, hydrogen ion is exchanged for base cations (including base metals) and sulfate is reduced to sulfide.

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

    USGS Publications Warehouse

    Koski, Randolph A.

    1979-01-01

    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

  20. Geology

    NASA Technical Reports Server (NTRS)

    Stewart, R. K.; Sabins, F. F., Jr.; Rowan, L. C.; Short, N. M.

    1975-01-01

    Papers from private industry reporting applications of remote sensing to oil and gas exploration were presented. Digitally processed LANDSAT images were successfully employed in several geologic interpretations. A growing interest in digital image processing among the geologic user community was shown. The papers covered a wide geographic range and a wide technical and application range. Topics included: (1) oil and gas exploration, by use of radar and multisensor studies as well as by use of LANDSAT imagery or LANDSAT digital data, (2) mineral exploration, by mapping from LANDSAT and Skylab imagery and by LANDSAT digital processing, (3) geothermal energy studies with Skylab imagery, (4) environmental and engineering geology, by use of radar or LANDSAT and Skylab imagery, (5) regional mapping and interpretation, and digital and spectral methods.

  1. The Geology, Geochemistry and Alteration of the Westwood Au-Zn-Cu Deposit, Abitibi Subprovince, Canada

    NASA Astrophysics Data System (ADS)

    Wright-Holfeld, A.; Mercier-Langevin, P.; Dubé, B.

    2009-05-01

    ore zones. There is relatively little change in Si, although an apparent enrichment may be present in some intervals. These major element trends reflect the abundances of alteration minerals such as garnet, biotite, chlorite, and sericite. The Westwood study contributes to better geological and geochemical exploration models for gold-rich VMS systems in Archean greenstone belts.

  2. Nd isotopic gradients in upper crustal magma chambers: Evidence for in situ magma-wall-rock interaction

    SciTech Connect

    Farmer, G.L.; Tegtmeyer, K.J.

    1990-01-01

    Multiple Nd isotopic analyses were obtained for one metaluminous and two peralkaline Tertiary rhyolitic ash-flow tuffs in the Great Basin to determine whether upper crustal silici magmas chemically evolve under closed- or open-system conditions. All the ash-flow tuffs analyzed show significant internal Nd isotopic variations. The largest variations occur within the peralkaline Double-H Mountains Tuff ({epsilon}{sub Nd} = +2.0 to +6.4) at the McDermitt volcanic field in north-central Nevada, and the smallest within the metaluminous Topopah Spring Tuff ({epsilon}{sub Nd} = {minus}10.6 to {minus}11.7) at the southwestern Nevada volcanic field. In all cases the isotopic variation are correlated with magmatic Nd contents, even though the Nd concentrations decreased roofward for the metaluminous rhyolite and increased for the peralkaline rhyolites. The consistent positive correlation between [Nd] and {epsilon}{sub Nd} provides strong evidence for in situ open-system addition of low {epsilon}{sub Nd} wall-rock material to the silicic magmas during their residence in the upper crust. The proportion of wall-rock Nd required to produce the isotopic zonations is small (1 to 15 mol%) for both the peralkaline and metaluminous rhyolites. All levels of the parental magmas sampled by the ash-flow tuffs, and not just magma occupying the roof zone, were open to wall-rock interaction. These results suggest that upper crustal silicic magma bodies evolve under open-system conditions and the effects of such processes should be addressed in models for their chemical differentiation.

  3. The stable isotope geochemistry of acid sulfate alteration

    USGS Publications Warehouse

    Rye, R.O.; Bethke, P.M.; Wasserman, M.D.

    1992-01-01

    Acid sulfate wall-rock alteration, characterized by the assemblage alunite + kaolinite + quartz ?? pyrite, results from base leaching by fluids concentrated in H2SO4. Requisite amounts of H2SO4 can be generated by different mechanisms in three principal geologic environments: 1) by atmospheric oxidation of sulfides in the supergene environment, 2) by atmospheric oxidation at the water table in the steam-heated environment of H2S released by deeper, boiling fluids, and 3) by the disproportionation of magmatic SO2 to H2S and H2SO4 during condensation of a magmatic vapor plume at intermediate depths in magmatic hydrothermal environments in silicic and andesitic volcanic terranes. In addition, coarse vein alunite may form in a magmatic steam environment. -from Authors

  4. Microbially Mediated Glass Alteration in the Geological Record: Textural clues for Microbial Functions.

    NASA Astrophysics Data System (ADS)

    Staudigel, H.; Furnes, H.; McLoughlin, N.; Banerjee, N.

    2007-12-01

    Fe and Mn oxidizing microbes interact with their environment through the microbially mediated formation of Fe/Mn oxides and through the corrosion textures they may leave behind in the solids they colonize and from which they extract nutrients. Understanding the geo-biology of Fe and Mn oxidation may focus on the study of the microbes themselves, the mineral products, its biocorrosion features and the relationships between these types of observations. We have reviewed our own data on glass bio-corrosion and in particular the wider literature on microbial mineral tunneling to develop a two stage biocorrosion model for volcanic glass that offers feedback for our understanding of the mechanisms and the dynamics of microbial dissolution. Traces of microbially mediated dissolution of volcanic glass are commonly observed in volcanic glass found in submarine volcanoes on the seafloor, and in uplifted submarine volcanoes of almost any geological age back to the origin of life. Two main bioalteration textures care observed, granular and tubular. Based on a comparison of these features in particular with tunneling by ectomycorrhizal fungi, we propose two distinct types of biocorrosion that affects glass: (1) Granular alteration textures, made up of colonies of microbe-sized, near spherical mineral - filled cavities that form irregular clusters ranging to a tens of micron thick bands at the glas surfaces. These granular textures are interpreted as the result of microbial colonization. accompanied by dissolution of the glass in their contact surface, deposition of authigenic minerals and the formation of a biofilm, that eventually seals the glass from easy access by seawater for hydration, or from microbes accessing Fe (II) in the glass. (2) The most spectacular bioalteration feature, repesented by the formation of tubes cannot be easily formed by the former mechanism because near spherical, individual microbes are likely not to produce the directionality that is required to

  5. Forceful emplacement of the Eureka Valley-Joshua Flat-Beer Creek composite pluton into a structural basin in eastern California; internal structure and wall rock deformation

    NASA Astrophysics Data System (ADS)

    Morgan, Sven; Law, Richard; de Saint Blanquat, Michel

    2013-11-01

    Anisotropy of Magnetic Susceptibility parameters have been analyzed at 311 locations in the Eureka Valley-Joshua Flat-Beer Creek (EJB) pluton of eastern California. The large amount of data has allowed for the AMS parameters to be contoured using techniques that both reveal map-scale trends and emphasize small-scale differences. The contour maps suggest that magnetic susceptibility is dominantly controlled by composition of the magma but may also be affected by emplacement-related strain as the magma chamber inflated and forced the wall rocks outward. Pluton construction involved two major pulses of different composition magmas that were emplaced sequentially but with overlapping periods of crystallization. The magmas initially intruded as sill-like bodies into a structural basin. The magnetic foliation of the pluton cuts across internal magmatic contacts on the map scale and is parallel to local contacts between the pluton and surrounding metasedimentary wall rocks. The magnetic fabric is similar in orientation and symmetry to intense flattening strains recorded in the aureole rocks. The metasedimentary wall rocks have been shortened between 60 and 70% and this strain magnitude is approximately equal on the west, south, and east margins of the pluton. Strain in the wall rocks is dominantly flattening and concentrated into a narrow (1 km wide) inner aureole. Mapping of bedding/cleavage intersection lineations south of the pluton indicates that the magma made room for itself by translating the wall rocks outward and rotating the already inward dipping wall rocks of the structural basin to sub-vertical. Stretching of the inner aureole around an expanding magma chamber was responsible for the intense shortening. Limited data on the Marble Canyon pluton to the south of the EJB pluton indicates a very similar emplacement process.

  6. Opportunity, Geologic and Structural Context of Aqueous Alteration in Noachian Outcrops, Marathon Valley and Rim and Endeavour Crater

    NASA Technical Reports Server (NTRS)

    Crumpler, L. S.; Arvidson, R. E.; Mittlefehldt, D. W.; Jolliff, B. L.; Farrand, W. H.; Fox, V.; Golombek, M. P.

    2016-01-01

    In its 12th year of exploration and 1600 sols since arrival at the rim of the 22 km-diameter Noachian Endeavour impact crater, Mars Exploration Rover Opportunity traversed from the summit of the western rim segment "Cape Tribulation" to "Marathon Valley", a shallow trough dissecting the rim and the site of strong orbital detection of smectites. In situ analysis of the exposures within Marathon Valley is establishing some of the geologic and geochemical controls on the aqueous alteration responsible for smectite detection known to occur in crater rims throughout Noachian terrains of Mars.

  7. Opportunity In Situ Geologic Context of Aqueous Alteration Along Offsets in the Rim of Endeavour Crater

    NASA Technical Reports Server (NTRS)

    Crumpler, L. S.; Arvidson, R. E.; Farrand, W. H.; Golombek, M. P.; Grant, J. A.; Ming, D. W.; Mittlefehldt, D. W.; Parker, T. J.

    2015-01-01

    Mars Exploration Rover Opportunity traversed 7.9 km and 27 degrees of arc along the rim of the 22 km-diameter Noachian "Endeavour" impact crater since its arrival 1200 sols ago. Areas of aqueous and low-grade thermal alteration, and changes in structure, attitude, and macroscopic texture of outcrops are notable across several discontinuities between segments of the crater rim. The discontinuities and other post-impact joints and fractures coincide with sites of apparent deep fluid circulation processes responsible for thermal and chemical alteration of local outcrops.

  8. Geology, alteration, and lithogeochemistry of the Hood volcanogenic massive sulfide (VMS) deposits, Nunavut, Canada

    NASA Astrophysics Data System (ADS)

    Mills, Hannah K.; Piercey, Stephen J.; Toole, Trish

    2016-04-01

    The Hood volcanogenic massive sulfide (VMS) deposits are hosted by the ~2.68 Ga Amooga Booga volcanic belt (ABVB) in the northwestern Archaen Slave Craton and consist of three deposits (Hood 10, 41, and 41A) and three occurrences (46, 461, and 462). The mineralized zones consist of massive to semi-massive pyrrhotite, pyrite, chalcopyrite, sphalerite, and galena hosted predominantly by felsic volcanic flows within the predominantly mafic ABVB. The mineralized lenses occur at different stratigraphic levels and have textural, alteration, and stratigraphic features consistent with formation via subseafloor replacement. The felsic volcanic rocks in the Hood deposits can be subdivided into groups based on immobile trace element geochemistry. The main felsic types (A and B) are petrographically indistinguishable. Type A has higher high field strength element (HSFE) and rare earth element (REE) contents than type B, suggesting a higher temperature of formation. Type A rocks also have higher Nb/Ta values indicative of a greater mantle input in their genesis compared to type B rocks. Mineralization is more closely associated with type A than type B rocks. The two mafic volcanic rock types previously identified in the ABVB, type I and type II, both occur within the Hood deposits. The type II mafic group is interpreted to be the result of variable crustal contamination of type I magma. The volcanic rocks of the ABVB are interpreted to have formed in a continental margin arc/back-arc setting. The genesis of these magmatic suites involved magmatic underplating and emplacement through pre-existing sialic basement that resulted in crustal melting, mantle-crust mixing, and contamination leading to the aforementioned geochemical features in both mafic and felsic suites. This type of extensional tectonic environment was likely associated with high heat flow and is similar to global VMS environments proximal to extending continental margins (e.g., Sturgeon Lake, Bathurst, and

  9. The geochemical evolution of clinopyroxene in the Roman Province: A window on decarbonation from wall-rocks to magma

    NASA Astrophysics Data System (ADS)

    Mollo, S.; Vona, A.

    2014-04-01

    We present results from magma-carbonate interaction experiments designed to shed light on the geochemical evolution of clinopyroxene in the Roman Province (central Italy). Atmospheric pressure experiments were performed at 1140, 1160 and 1180 °C under NNO, MH and air oxygen buffering conditions. The starting materials were a shoshonite and a phonotephrite doped with different amounts of CaO and CaO + MgO whose stoichiometric proportions reproduced the assimilation by magmas of calcite and dolomite, respectively. The results show that clinopyroxenes, spinels and residual glasses are ubiquitous phases in all run-products. Calcite-doped runs crystallize more clinopyroxene than dolomite-doped runs at the same conditions. This leads to the formation of strong desilicated CaO-rich melts showing compositions comparable to those of magmatic skarns. During magma-carbonate interaction, the content of Fe3 + in clinopyroxene increases with increasing fO2 promoting the substitution of Al for Si in tetrahedral site. Local charge imbalances are also compensated by the incorporation of highly charged cations, such as Ti, into the crystal lattice. According to this cation substitution, Al-Ca-Fe3 +-Ti-rich clinopyroxenes of the skarn environment testify to continuous CO2 fluxes produced by the thermal decomposition of carbonate wall-rocks. Nevertheless, the oxidative capacity of CO2 progressively decreases from the skarn shells towards the interior of the magma chamber driving the crystallization of Si-Fe2 +-Mg-rich clinopyroxenes.

  10. The Magma Chamber Simulator: Modeling the Impact of Wall Rock Composition on Mafic Magmas during Assimilation-Fractional Crystallization

    NASA Astrophysics Data System (ADS)

    Creamer, J. B.; Spera, F. J.; Bohrson, W. A.; Ghiorso, M. S.

    2012-12-01

    Although stoichiometric titration is often used to model the process of concurrent Assimilation and Fractional Crystallization (AFC) within a compositionally evolving magma body, a more complete treatment of the problem involves simultaneous and self-consistent determination of stable phase relationships and separately evolving temperatures of both Magma (M) and Wall Rock (WR) that interact as a composite M-WR system. Here we present results of M-WR systems undergoing AFC forward modeled with the Magma Chamber Simulator (MCS), which uses the phase modeling capabilities of MELTS (Ghiorso & Sack 1995) as the thermodynamic basis. Simulations begin with one of a variety of mafic magmas (e.g. HAB, MORB, AOB) intruding a set mass of Wall Rock (e.g. lherzolite, gabbro, diorite, granite, metapelite), and heat is exchanged as the M-WR system proceeds towards thermal equilibrium. Depending on initial conditions, the early part of the evolution can involve closed system FC while the WR heats up. The WR behaves as a closed system until it is heated beyond the solidus to critical limit for melt fraction extraction (fc), ranging between 0.08 and 0.12 depending on WR characteristics including composition and, rheology and stress field. Once fc is exceeded, a portion of the anatectic liquid is assimilated into the Magma. The MCS simultaneously calculates mass and composition of the mineral assemblage (Magma cumulates and WR residue) and melt (anatectic and Magma) at each T along the equilibration trajectory. Sensible and latent heat lost or gained plus mass gained by the Magma are accounted for by the MCS via governing Energy Constrained- Recharge Assimilation Fractional Crystallization (EC-RAFC) equations. In a comparison of two representative MCS results, consider a granitic WR intruded by HAB melt (51 wt. % SiO2) at liquidus T in shallow crust (0.1 GPa) with a WR/M ratio of 1.25, fc of 0.1 and a QFM oxygen buffer. In the first example, the WR begins at a temperature of 100o

  11. Wall Rock Assimilation and Magma Migration in the Sierra Nevada Batholith: A Study of the Courtright Intrusive Zone, Central California

    NASA Astrophysics Data System (ADS)

    Torrez, G.; Putirka, K. D.

    2010-12-01

    The Sierra Nevada Batholith is composed of various plutons that interact with each other, and with pre- and syn-batholith metamorphic rocks. In the central part of the Sierra Nevada Batholith, at Courtright Reservoir in California, the younger Mt. Givens Pluton (87-93 Ma; McNulty et al., 2000) intrudes the Dinkey pluton (103 Ma; Bateman et al., 1964), and metasediments (a metamorphic screen) that, in places, separate the two plutons. This Courtright Reservoir Intrusive zone, as termed by Bateman et al. (1964), provides an ideal setting to examine the dynamics of intrusion and assimilation. Whole rock major and trace element compositions of the plutons, their mafic enclaves, and the metasediments, show that all such samples, from both plutons, fall on a single mixing trend. We thus infer that magmas parental to both plutons were roughly similar in composition, and assimilated significant amounts of the same, or very similar metasedimentary wall rocks. We also examined changes in whole rock compositions within the Mt. Givens pluton, as a function of distance from the two rock units with which it is now in contact (the metasediments, and the Dinkey Creek). In the vicinity of the contact between are an abundance of enclaves that are rounded, and appear to have been transported in vertical pipes. Whole rock analysis of the host granitoid material that surrounds these enclaves is clearly more mafic than the granitoid magmas from interior parts of the pluton. These whole rock compositions indicate that the pluton becomes more homogenous moving away from the contact, with a compositional decay occurring over a span of about 50-100 m. There are at least two possible interpretations. The compositional decay may represent a diffusive exchange of mass between an early crystallizing marginal phase of the pluton and the pluton interior. Another (not mutually incompatible) possibility is that the mafic margins represent pipes or tubes (Paterson, 2010), related to some convective

  12. Alteration and fluid flow around a sulfide-carbonate-quartz vein, Lucky Friday mine, Northern Idaho

    SciTech Connect

    Gitlin, E.C.

    1985-01-01

    Wall rocks at the Lucky Friday mine, Coeur d'Alene district, Idaho, contain a >500m wide zone about a steeply dipping Pb-Zn-Ag vein. This zone has experienced local conditions distinct from the regional metamorphism of the quartzite + argillite host rock. Within the district, the host rock (Precambrian Revett Formation) has undergone low grade metamorphism and contains varying proportions of quartz, phengitic muscovite, detrital alkali feldspar, magnetite, hematite, ilmenite, rutile, zircon, tourmaline, +/- calcite, +/- ankeritic dolomite. In contrast, the Lucky Friday wall rocks lack feldspar and Fe-bearing oxides, and contain Fe-poor muscovite and up to 40% carbonate: siderite, ankerite, and/or calcite. A comparison of district-wide Revett rocks with Lucky Friday wall rocks suggests that the wall rocks have undergone localized dephengitization with concomitant Fe-enrichment in the carbonates and Fe-depletion of the oxides. Pertinent metamorphic reactions consume CO/sub 2/ and liberate H/sub 2/O. Fluid inclusions from the vein and wall rock stringers have homogenization temperatures from approx. =200/sup 0/ to <375/sup 0/C, but they define no temperature gradient. With few exceptions, compositions of the carbonates are identical throughout the altered wall rock. These observations suggest that the carbonate subzone contacts are not isograds but isofluxes: the loci of equivalent fluid/reactant mineral ratio. The disposition of isofluxes around a dominant fluid channelway, i.e. the vein, affords an opportunity to interpret fluid flow pathways during low temperatures metamorphism.

  13. Geology and hydrothermal alteration at the Madh adh Dhahab epithermal precious-metal deposit, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Doebrich, J.L.; LeAnderson, J.P.

    1984-01-01

    Vein-related alteration consisting of quartz-sericite-pyrite, chloritic, argillic, and silicic halos was superimposed on broad zones of pervasive silicic, potassic, and argillic alteration that surrounds the rhyolite intrusive body. Quartz-sericite-pyrite alteration associated with the earliest stage of mineralization was followed by broad, pervasive, stratigraphically controlled potassic alteration. Subsequent mineralization was accompanied by quartz-sericitepyrite alteration and was followed by the main stage of mineralization that formed strong chloritic alteration halos. Development of broad zones and halos of argillic alteration also may have been related to the main stage of mineralization. Development of silicic halos was characteristic of the late stages of mineralization. Broad, pervasive propylitic alteration was then superimposed on all alteration types and represents cooling and inward encroachment of the hydrothermal system. All alteration, except the early silicic alteration is interpreted to have been related to circulating meteoric fluids heated by the rhyolite.

  14. Initial Melting and wall-rock flux-melting of a wet multi-component mantle and its implications for the formation of MORB

    NASA Astrophysics Data System (ADS)

    Morgan, J. P.; Hasenclever, J.

    2013-12-01

    We explore several simple scenarios for wet melting of a heterogeneous multi- component mantle. In our melting formulation the mantle is viewed as a mixture consisting of a heterogeneously depleted peridotite matrix with embedded veins of fertile peridotite and/or geochemically enriched pyroxenite. These lithological units differ in their mineral composition but are assumed to have diffusively equilibrated both their water/hydrogen content and temperature over the hundreds of millions to billions of years prior to entering a melting region. During the melting process, however, only thermal but not chemical (water) equilibrium is assumed between the lithologies, which is a reasonable assumption for veins with thicknesses on the order of few tens to few hundreds of meters, a thermal diffusivity of 10^-6 m^2/s and a diffusivity of hydrogen of less than 3*10^-9 m^2/s. The thermodynamic formulation of the multi-component melting process, during which all components have to share thermal energy, is based on Phipps Morgan (2001). The wet melting parameterization by Katz et al. (2003) has been included in the thermodynamic formulation by modifying its solidus-depletion-dependence and treating water partitioning during melting as partitioning of a trace element with a D-value like that of Ce. Usually, fractional melting with a small trapped melt fraction is assumed. We will mostly discuss results from 1-D model calculations, which represent the idealized decompression of a multi-component mantle rising underneath a mid-ocean ridge. Melt-migration is assumed to occur as vertical ascent within each column. We have also extended the formulation to examine the effects of rising melts on 'flux-melting' the wall-rock through which they migrate. We are still testing to see if this mechanism can be the reason why ridge melts almost always have major element chemistries in equilibrium with a peridotitic mantle, while the incompatible trace elements in EMORB reflect the influence of

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

    USGS Publications Warehouse

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

    2002-01-01

    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

  16. Identification of hydrated silicate minerals on Mars using MRO-CRISM: Geologic context near Nili Fossae and implications for aqueous alteration

    USGS Publications Warehouse

    Ehlmann, B.L.; Mustard, J.F.; Swayze, G.A.; Clark, R.N.; Bishop, J.L.; Poulet, F.; Des Marais, D.J.; Roach, L.H.; Milliken, R.E.; Wray, J.J.; Barnouin-Jha, O.; Murchie, S.L.

    2009-01-01

    diversity and geologic context of alteration minerals found in the region around the Nili Fossae indicates several episodes of aqueous activity in multiple distinct environments. Copyright 2009 by the American Geophysical Union.

  17. Stable isotope and chemical systematics of pseudotachylyte and wall rock, Homestake shear zone, Colorado, USA: Meteoric fluid or rock-buffered conditions during coseismic fusion?

    NASA Astrophysics Data System (ADS)

    Moecher, David P.; Sharp, Zachary D.

    2004-12-01

    A hydrous fluid phase is critical in controlling effective stress and fault mechanics, and influencing the mineralogy and strength of materials within fault zones. Oxygen and hydrogen isotope and chemical analysis of wall rock gneiss, pseudotachylyte, and selected minerals in gneiss and pseudotachylyte from the Homestake shear zone was used to assess whether melting occurred in the presence of meteoric water or involved only minor amounts of H2O derived from micas in wall rock gneiss. Bulk pseudotachylyte has slightly lower δ18OSMOW than the whole rock protolith. δD for one bulk pseudotachylyte is essentially identical to biotite in gneiss; δD for two samples is lower by ˜20‰. Bulk pseudotachylyte has lower SiO2 and K2O, and higher Al2O3, FeO, MgO, CaO, and H2O, than gneiss. The lower SiO2 of pseudotachylyte compared to gneiss is explained by physical segregation of 25 to 72 volume % of quartz clasts from the mobile melt phase. Samples of gneiss and pseudotachylyte define a SiO2-δ18O mixing line between quartz and the most SiO2- and 18O-depleted pseudotachylyte. Physical segregation of quartz (highest oxygen isotope composition in the pseudotachylyte-gneiss system) accounts for the slightly lower oxygen isotope composition of bulk pseudotachylyte relative to gneiss. The similar δD of pseudotachylyte and biotite from gneiss in one sample is consistent with dehydration melting of biotite during frictional heating and dissolution of biotite-derived H2O in the melt. Late devitrification of glass and formation of greater amounts of fine-grained muscovite, accompanied by 10-30% loss of hydrogen as H2O, results in lower δD values in other samples. In general, melt generation occurred in a fault zone closed to infiltration of meteoric water. There was no free, H2O-rich pore fluid present at the time of slip to potentially influence the behavior of the fault.

  18. Geology, alteration, and magmatic-hydrothermal history of The Geysers felsite -- potential applications for exploration and development

    SciTech Connect

    Hulen, J.B.; Nielson, D.L. )

    1993-01-01

    The [open quotes]felsite[close quotes] is a shallow, young, granitic intrusive body centrally located within and beneath. The Geysers steam field. The field and the felsite are coaxial, and hydrothermal alteration effected by hot-water dominated geothermal systems antedating the modern steam reservoir shows systematic vertical zonation with respect to the pluton. The research summarized in this communication was undertaken both to clarify the role of the pluton in reservoir evolution, and to characterize critical felsite-specific controls on the fields's deep porosity and permeability. The felsite comprises at least three major intrusive phases. Two are high-silica granites probably older than 1.3 Ma. The third is granodiorite (1 Ma), temporally and chemically equivalent to overlying extrusive dacites of the Clear Lake volcanic field. All three intrusive phases are too old to be heat sources for the modern steam field, but probably were the heat engines for the prior liquid-dominant systems. Younger, deeper magmatic heat sources are strongly implied for the current vapor-dominated regime. Porosity in the felsite is provided by: (1) Extensively mineralized fractures and breccias, probably of both tectonic and high-temperature hydrothermal origin; and (2) miarolitic cavities in the upper levels of the pluton. The latter could be analogous to calcite-dissolution cavities in overlying metagraywacke -- they could serve as storage sites for the fields's liquid water reserves. Porosity in these fractures, breccias, and vugs in partially occluded by hydrothermal vein minerals deposited in prior hotwater-dominated systems --tourmaline, ferroaxinite, quartz, potassium feldspar, epidote, actinolite, prehnite, and many others. Such secondary mineralization conceptually could serve as an excellent exploration guide to potentially productive portions of the felsite beyond the field's present boundaries.

  19. Immiscibility between calciocarbonatitic and silicate melts and related wall rock reactions in the upper mantle: a natural case study from Romanian mantle xenoliths

    NASA Astrophysics Data System (ADS)

    Chalot-Prat, Françoise; Arnold, Michel

    1999-04-01

    more Ca-rich than those in the silicate matrix; spinels are relatively Al- and Mg-poor but rather Cr- and Fe-rich. Existence of only one titanium oxide (armalcolite) and various pairs of pyroxenes suggest crystallization temperatures in the range 1100-1200°C and pressures between 10-15 kb. Feldspar compositions in silicate materials, which vary continuously from labradorite to sanidine, are consistent with hypersolvus and dry crystallization conditions. All of these results provide evidence that immiscibility occurred at mantle depth as the liquid was forcibly injected during hydraulic fracturing of the mantle. The compositions of conjugate melts suggest a very large miscibility gap, as expected at high pressure in a dry environment from the experiments of Kjarsgaard and Hamilton [Kjarsgaard, B.A., Hamilton, D.L., 1988. Liquid immiscibility and the origin of alkali-poor carbonatites. Mineral. Mag. 52, 43-55; Kjarsgaard, B.A., Hamilton, D.L., 1989. The genesis of carbonatites by immiscibility. In: Bell, K. (Ed.), Carbonatites: Genesis and Evolution. Unwyn Hyman, London, pp. 388-404.]. The parental melt was carbonate, silica-undersaturated and rich in F, Cl and CO 2. Both immiscible melts were water-undersaturated. The cooling rate until total crystallization in veinlets was very slow, limited and necessarily occurred at mantle depth. Wall rock reactions leading to the formation of Ca-rich pyroxene at the expense of mantle enstatite or olivine occurred only at the contact with somewhat alkali-rich carbonatitic or silicate melts. Calcite, always anhedral, is the last mineral to crystallize. It is a differentiation product formed by magmatic crystallization or wall rock reaction. In some cases, given the rarity of any other minerals, it may be the product of the crystallization of a pure sövite immiscible melt.

  20. Characterization of Unfractured Wall Rocks of TCDP Hole-B by Combination of Thermal-Property and TDR Measurements in Laboratory

    NASA Astrophysics Data System (ADS)

    Matsubayashi, O.; Lin, W.; Hirono, T.; Song, S.; Hung, J.

    2005-12-01

    As part of comprehensive studies of non-destructive physical properties of the cores from Hole-B drilled for the Taiwan Chelungpu-fault Drilling Project (TCDP), we have closely examined the data of combined thermal-property and TDR (water content) measurements which were carefully performed in laboratory. The purpose is to establish the bulk characteristics of thermal-properties in response to water content for the non-fractured part of the formations in TCDP Hole-B, so that we can properly assess the baseline thermal regime undisturbed by the thermal effect of fault activity. The sections studied in this work are unfractured parts of the cores (i) from 1142 to 1170m, and (ii) from 1200 to 1235m of Hole-B, which compose the wall rocks immediately below the fault zones of 1137m and 1194m depths, respectively. The instruments used were a transient type thermal-property analyzer with a half space probe for thermal conductivity, and a parallel-rod sensor probe for TDR water content, both are commercially available. Measured value of thermal conductivity ranges from 2.2 to 3.7 W/mK, while TDR water content value covers the approximate range of 15 to 26 percent. It is found by a correlation plot of thermal conductivity (Lamda) vs. water content (w) that within each section there is a very good negative correlation between the two for most of the good quality measurements, indicating thermal conductivity being primarily controlled by the volume ratio of solid grain to interstitial water. Such a relationship is reasonable and would be very useful in evaluation of thermal-properties of the whole section along the drillhole, and also for estimating the thermal-properties of fault zones in particular, which is always difficult to measure directly due to practical constrains.

  1. New ages on intrusive rocks and altered zones in the Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1977

    USGS Publications Warehouse

    Wilson, Frederic H.; Detterman, Robert L.; Silberman, Miles L.

    1978-01-01

    Preliminary potassium-argon dating of intrusive rocks and altered zones in the Chignik and Sutwik Island quadrangles of the Alaska Peninsula seems to indicate at least three and possibly four Tertiary ages of alteration and mineralization.

  2. Desilicification and iron activation-reprecipitation in the high-grade magnetite ores in BIFs of the Anshan-Benxi area, China: Evidence from geology, geochemistry and stable isotopic characteristics

    NASA Astrophysics Data System (ADS)

    Li, Hou-Min; Yang, Xiu-Qing; Li, Li-Xing; Zhang, Zhao-Chong; Liu, Ming-Jun; Yao, Tong; Chen, Jing

    2015-12-01

    The high-grade magnetite ores related to banded iron formations (BIFs) in the Anshan-Benxi area, Liaoning Province in China, have been widely interpreted as the product of replacement of protore by epigenetic hydrothermal fluids. The high-grade iron ore reserves in the mining area II (164 million tons) in the Gongchangling (G2) and Qidashan-Wangjiabuzi (QW) iron deposits (11.45 million tons) are the largest deposits in the Anshan-Benxi area. We present a detailed comparison of the geology, geochemical and stable isotopic compositions of the iron ores in the G2 with those in the QW to constrain the role of desilicification and iron activation-reprecipitation in converting the BIFs to high-grade magnetite ores. These two deposits show marked difference in wall-rock alteration, geochemical features, and oxygen and sulfur isotopic compositions. Wall-rock alteration in the G2 is characterized by garnetization, actinolitization, and chloritization, whereas the QW shows chloritization, biotitization and sericitization. The geochemistry of altered rocks in the G2 is characterized by slight REE fractionation, positive Eu and no significant Ce anomalies, whereas the QW is characterized by high ΣREE contents, strong REE fractionation, and the absence of significant Eu and Ce anomalies. High-grade iron ores in the G2 show similar δ18OV-SMOW values for magnetite, lower δ18OV-SMOW values for quartz and higher δ34SV-CDT values for pyrite when compared to the BIFs, whereas the QW shows lower δ18OV-SMOW values for magnetite, similar δ18OV-SMOW values for quartz and similar δ34SV-CDT values for pyrite. These features indicate that desilicification process by hypogene alkaline-rich hydrothermal fluids were possibly responsible for the formation of high-grade iron ores in the G2 whereas iron activation-reprecipitation process by migmatitic-hydrothermal fluids generated the high-grade iron orebodies in QW.

  3. Digital image processing techniques for detecting surface alteration - An application on the Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1983

    USGS Publications Warehouse

    York, James; Wilson, Frederic H.; Gamble, Bruce M.

    1985-01-01

    The tectonic evolution of the Alaska Peninsula makes it a likely area for the discovery of significant mineral deposits. However, because of problems associated with remoteness and poor weather, little detailed mineral exploration work has been carried on there. This study focuses on using Landsat multispectral scanner data for the Port Moller, Stepovak Bay, and Simeon of Island Quadrangles to detect surface alteration, probably limonitic (iron oxide staining) and(or) argillic (secondary clay minerals) in character, that could be indicative of mineral deposits. The techniques used here are useful for mapping deposits that have exposed surface alteration of at least an hectare, the approximate spatial resolution of the Landsat data. Virtually cloud-free Landsat coverage was used, but to be detected, the alteration area must also be unobscured by vegetation. Not all mineral deposits will be associated with surface alteration, and not all areas of surface alteration will have valuable mineral deposits.

  4. Geology of five small Australian impact craters

    USGS Publications Warehouse

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

    2005-01-01

    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.

  5. Host rocks and their alterations as related to uranium-bearing veins in the United States

    USGS Publications Warehouse

    Walker, George W.

    1956-01-01

    This paper, dealing with the different kinds of host rocks and their alterations associated with uranium-bearing veins in the United States, is a chapter of a comprehensive report entitled , "Geology of uranium-bearing vein deposits in the United States," in preparation by George W. Walker, Frank W. Osterwald, and others. The comprehensive report will include detailed information on tectonic and structural setting, kinds of host rocks, wall-rock alteration, mineralogy, physical characteristics, processes of deposition, and concepts of origin of uraniferous veins; but, because it will not be completed until sometime in the future, some chapters of the report are being transmitted as they are finished. Part of an introductory chapter to the comprehensive report entitled, "Classification and distribution of uranium-bearing veins in the United States" (Walker and Osterwald, 1956) has already been transmitted; several of the terms used herein are defined in the introductory chapter. Data included in this chapter demonstrate that uranium-bearing veins are: 1) in rocks of nearly all textural, chemical, and mineralogic types; 2) most abundant in holocrystalline, commonly equigranular, igeneous and metamorphic rocks characterized by a moderate to high silica content and and by similar physical properties. Although some of the physiochemical properties of the host rocks are discussed in terms of favorability or nonfavoribility for uranium deposition, the principal purpose of this chapter is to establish the petroloic environment in which uranium-bearing veins have been found. Because favorability or nonfavorability of host rocks is related complexly to the chemistry of ore solutions and to methods or uranium transport and deposition, several hypothetical processes of transport and deposition have been referred to briefly; these and other hypotheses will be outlines and discussed in greater detail in a subsequent chapter. The compilation of data leading to this report and its

  6. Archeological Geology

    ERIC Educational Resources Information Center

    Rapp, George

    1977-01-01

    Describes the rapid expansion of archeological geology, especially in the area of archeological excavations, where geologists use dating techniques and knowledge of geological events to interpret archeological sites. (MLH)

  7. Mathematical Geology.

    ERIC Educational Resources Information Center

    Jones, Thomas A.

    1983-01-01

    Mathematical techniques used to solve geological problems are briefly discussed (including comments on use of geostatistics). Highlights of conferences/meetings and conference papers in mathematical geology are also provided. (JN)

  8. International Geology

    ERIC Educational Resources Information Center

    Hoover, Linn

    1977-01-01

    Briefly discusses recent international programs in various areas of geology, including land-use problems, coping with geological hazards, and conserving the environment while searching for energy and mineral resources. (MLH)

  9. Geology, alteration and mesothermal Au-Ag-mineralization associated with a volcanic-intrusive complex at Mt. Shamrock-Mt. Ophir, SE Queensland

    NASA Astrophysics Data System (ADS)

    Williams, P. J.

    1991-04-01

    Au-Ag mineralization in the Mt-Shamrock — Mt. Ophir area of SE Queensland is related to a geographically-isolated calc-alkaline igneous centre consisting of high level plutonic and minor intrusions emplaced into the eroded remains of a silicic volcanic ediface and its basement. Mineralization occurs in both the igneous rocks and in the Permian siltstone country rocks and is controlled by a NE-trending structure parallel to Late Triassic lineaments. This structure is unrelated to, and younger than the exposed intrusions. Au-Ag-As-rich, Cu-Mo-poor mineralization occurs in breccias and veinlet networks within pervasively altered rocks characterized by silicification and H (sericite), CO2 (calcite-ankerite), Na (albite), B (tourmaline), and S (pyrite) metasomatism. Secondary mineral compositions suggest that most of this alteration occurred at temperatures between 350 ° and 400 °C. The alteration was complex in detail and characterized by multiple hydrothermal events and space and/or time variations of physico-chemical conditions. Although some of these features are similar to prophyry deposits the chemical character of the alteration and mineralization is not typical of Cu-Mo-Au porphyries and has more in common with tectonometamorphic Au deposits formed at considerably greater depths.

  10. Geologic map of the Sulphur Springs Area, Valles Caldera Geothermal System, New Mexico

    SciTech Connect

    Goff, F.E.; Gardner, J.N.

    1980-12-01

    The geologic and tectonic setting and geology of Sulphur Springs Area are described. Geologic faults, sheared or brecciated rock, volcanic vents, geothermal wells, hydrothermal alteration, springs, thermal springs, fumaroles, and geologic deposits are indicated on the map. (MHR)

  11. Physical geology

    SciTech Connect

    Skinner, B.; Porter, S.

    1987-01-01

    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.

  12. Geological gyrocompass

    NASA Astrophysics Data System (ADS)

    McKeown, M. H.; Beason, S. C.

    1988-08-01

    The geological gyrocompass is an accurate, portable instrument useful for geologic mapping and surveying which employs an aircraft gyrocompass, strike reference bars, a pair of sights and levelling devices for horizontally levelling the instrument. A clinometer graduated in degrees indicates the dip of the surface being measured.

  13. Engineering Geology

    ERIC Educational Resources Information Center

    Hatheway, Allen W.

    1978-01-01

    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)

  14. Geologic Time.

    ERIC Educational Resources Information Center

    Newman, William L.

    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.…

  15. Geologic time

    USGS Publications Warehouse

    Newman, William L.

    2000-01-01

    The Earth is very old 4 1/2 billion years or more according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.

  16. Mathematical Geology.

    ERIC Educational Resources Information Center

    McCammon, Richard B.

    1979-01-01

    The year 1978 marked a continued trend toward practical applications in mathematical geology. Developments included work in interactive computer graphics, factor analysis, the vanishing tons problem, universal kriging, and resource estimating. (BB)

  17. Engineering Geology

    ERIC Educational Resources Information Center

    Lee, Fitzhugh T.

    1974-01-01

    Briefly reviews the increasing application of geologic principles, techniques and data to engineering practices in the areas of land use and zoning controls, resource management energy programs and other fields. (BR)

  18. Destination: Geology?

    NASA Astrophysics Data System (ADS)

    Price, Louise

    2016-04-01

    "While we teach, we learn" (Roman philosopher Seneca) One of the most beneficial ways to remember a theory or concept is to explain it to someone else. The offer of fieldwork and visits to exciting destinations is arguably the easiest way to spark a students' interest in any subject. Geology at A-Level (age 16-18) in the United Kingdom incorporates significant elements of field studies into the curriculum with many students choosing the subject on this basis and it being a key factor in consolidating student knowledge and understanding. Geology maintains a healthy annual enrollment with interest in the subject increasing in recent years. However, it is important for educators not to loose sight of the importance of recruitment and retention of students. Recent flexibility in the subject content of the UK curriculum in secondary schools has provided an opportunity to teach the basic principles of the subject to our younger students and fieldwork provides a valuable opportunity to engage with these students in the promotion of the subject. Promotion of the subject is typically devolved to senior students at Hessle High School and Sixth Form College, drawing on their personal experiences to engage younger students. Prospective students are excited to learn from a guest speaker, so why not use our most senior students to engage and promote the subject rather than their normal subject teacher? A-Level geology students embarking on fieldwork abroad, understand their additional responsibility to promote the subject and share their understanding of the field visit. They will typically produce a series of lessons and activities for younger students using their newly acquired knowledge. Senior students also present to whole year groups in seminars, sharing knowledge of the location's geology and raising awareness of the exciting destinations offered by geology. Geology fieldwork is always planned, organised and led by the member of staff to keep costs low, with recent visits

  19. Structural Geology

    NASA Astrophysics Data System (ADS)

    Weber, John; Frankel, Kurt L.

    2011-05-01

    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.

  20. Geological Gyrocompass

    NASA Astrophysics Data System (ADS)

    McKeown, M. H.; Beason, S. C.

    1990-10-01

    The invention relates to a new and improved geologic mapping and surveying apparatus for providing accurate, dependable, and portable measurement of attitudes of planar surfaces in situations where magnetic compasses will not work. The invention provides a unique arrangement of the gyrocompass and power supply in a portable carrying case. A gyroscope is not dependent on the earth's magnetic field for a reference as is a magnetic compass. Therefore, the invention of a geological gyrocompass is immune to disturbances in the earth's magnetic field and nearly duplicates the Brunton compass accuracy but does not require an environment free of magnetic anomalies.

  1. Theoretical geology

    NASA Astrophysics Data System (ADS)

    Mikeš, Daniel

    2010-05-01

    Theoretical geology Present day geology is mostly empirical of nature. I claim that geology is by nature complex and that the empirical approach is bound to fail. Let's consider the input to be the set of ambient conditions and the output to be the sedimentary rock record. I claim that the output can only be deduced from the input if the relation from input to output be known. The fundamental question is therefore the following: Can one predict the output from the input or can one predict the behaviour of a sedimentary system? If one can, than the empirical/deductive method has changes, if one can't than that method is bound to fail. The fundamental problem to solve is therefore the following: How to predict the behaviour of a sedimentary system? It is interesting to observe that this question is never asked and many a study is conducted by the empirical/deductive method; it seems that the empirical method has been accepted as being appropriate without question. It is, however, easy to argument that a sedimentary system is by nature complex and that several input parameters vary at the same time and that they can create similar output in the rock record. It follows trivially from these first principles that in such a case the deductive solution cannot be unique. At the same time several geological methods depart precisely from the assumption, that one particular variable is the dictator/driver and that the others are constant, even though the data do not support such an assumption. The method of "sequence stratigraphy" is a typical example of such a dogma. It can be easily argued that all the interpretation resulting from a method that is built on uncertain or wrong assumptions is erroneous. Still, this method has survived for many years, nonwithstanding all the critics it has received. This is just one example of the present day geological world and is not unique. Even the alternative methods criticising sequence stratigraphy actually depart from the same

  2. Geologic Time.

    ERIC Educational Resources Information Center

    Albritton, Claude C., Jr.

    1984-01-01

    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)

  3. Local geology controlled the feasibility of vitrifying Iron Age buildings

    PubMed Central

    Wadsworth, Fabian B.; Heap, Michael J.; Damby, David E.; Hess, Kai-Uwe; Najorka, Jens; Vasseur, Jérémie; Fahrner, Dominik; Dingwell, Donald B.

    2017-01-01

    During European prehistory, hilltop enclosures made from polydisperse particle-and-block stone walling were exposed to temperatures sufficient to partially melt the constituent stonework, leading to the preservation of glassy walls called ‘vitrified forts’. During vitrification, the granular wall rocks partially melt, sinter viscously and densify, reducing inter-particle porosity. This process is strongly dependent on the solidus temperature, the particle sizes, the temperature-dependence of the viscosity of the evolving liquid phase, as well as the distribution and longevity of heat. Examination of the sintering behaviour of 45 European examples reveals that it is the raw building material that governs the vitrification efficiency. As Iron Age forts were commonly constructed from local stone, we conclude that local geology directly influenced the degree to which buildings were vitrified in the Iron Age. Additionally, we find that vitrification is accompanied by a bulk material strengthening of the aggregates of small sizes, and a partial weakening of larger blocks. We discuss these findings in the context of the debate surrounding the motive of the wall-builders. We conclude that if wall stability by bulk strengthening was the desired effect, then vitrification represents an Iron Age technology that failed to be effective in regions of refractory local geology. PMID:28079121

  4. Local geology controlled the feasibility of vitrifying Iron Age buildings.

    PubMed

    Wadsworth, Fabian B; Heap, Michael J; Damby, David E; Hess, Kai-Uwe; Najorka, Jens; Vasseur, Jérémie; Fahrner, Dominik; Dingwell, Donald B

    2017-01-12

    During European prehistory, hilltop enclosures made from polydisperse particle-and-block stone walling were exposed to temperatures sufficient to partially melt the constituent stonework, leading to the preservation of glassy walls called 'vitrified forts'. During vitrification, the granular wall rocks partially melt, sinter viscously and densify, reducing inter-particle porosity. This process is strongly dependent on the solidus temperature, the particle sizes, the temperature-dependence of the viscosity of the evolving liquid phase, as well as the distribution and longevity of heat. Examination of the sintering behaviour of 45 European examples reveals that it is the raw building material that governs the vitrification efficiency. As Iron Age forts were commonly constructed from local stone, we conclude that local geology directly influenced the degree to which buildings were vitrified in the Iron Age. Additionally, we find that vitrification is accompanied by a bulk material strengthening of the aggregates of small sizes, and a partial weakening of larger blocks. We discuss these findings in the context of the debate surrounding the motive of the wall-builders. We conclude that if wall stability by bulk strengthening was the desired effect, then vitrification represents an Iron Age technology that failed to be effective in regions of refractory local geology.

  5. Local geology controlled the feasibility of vitrifying Iron Age buildings

    USGS Publications Warehouse

    Fabian B Wadsworth,; Michael J Heap,; Damby, David; Kai-Uwe Hess,; Jens Najorka,; Jérémie Vasseur,; Dominik Fahrner,; Donald B Dingwell,

    2017-01-01

    During European prehistory, hilltop enclosures made from polydisperse particle-and-block stone walling were exposed to temperatures sufficient to partially melt the constituent stonework, leading to the preservation of glassy walls called ‘vitrified forts’. During vitrification, the granular wall rocks partially melt, sinter viscously and densify, reducing inter-particle porosity. This process is strongly dependent on the solidus temperature, the particle sizes, the temperature-dependence of the viscosity of the evolving liquid phase, as well as the distribution and longevity of heat. Examination of the sintering behaviour of 45 European examples reveals that it is the raw building material that governs the vitrification efficiency. As Iron Age forts were commonly constructed from local stone, we conclude that local geology directly influenced the degree to which buildings were vitrified in the Iron Age. Additionally, we find that vitrification is accompanied by a bulk material strengthening of the aggregates of small sizes, and a partial weakening of larger blocks. We discuss these findings in the context of the debate surrounding the motive of the wall-builders. We conclude that if wall stability by bulk strengthening was the desired effect, then vitrification represents an Iron Age technology that failed to be effective in regions of refractory local geology.

  6. Geology of the Plumtree area, Spruce Pine district, North Carolina

    USGS Publications Warehouse

    Brobst, Donald Albert

    1953-01-01

    dikes of post-pegmatite age (Triassic?). The alaskite and pegmatite have similar bulk compositions, notably low in iron (0.3 percent). The major constituents in order of decreasing abundance are plagioclase, perthitic microcline, quartz, and muncovite. All of these minerals, as well as clay deposits derived from the weathering of alaskite under old terraces, have economic value. The zoned pegmatites contain fewer zones which are less complex mineralogically than those in the pegmatites of many other areas. These essentially unmetamorphosed bodies were intruded approximately at the peak of the regional metamorphism. Their emplacement was controlled by local structure and rock type. The source of this igneous material may have been the mobilized portions of the Cranberry gneiss which underlies the area. The dunite bodies were intruded early in the metamorphic cycle. The bodies are commonly zoned: from the wall rock inwards (1) talc-antrophyllite-serpentine fringe, (3) serpentinized dunite, (3) granular olivine core. Dunite, chromite, vermiculite, and anthophyllite are the major economic commodities. Extensive hydrothermal alteration of dunite bodies produced soapstone. The area is the northeast end of a southwest plunging synclinorium about 20 miles wide with the steeper limb on the northwest side. There are three structural zones: zone I on the northwest is characterized by the northeast-trending isoclinal folds with steep southeast dips; zone II on the southwest includes an area of rocks with low and variable dip; zone III is the complex central core. In the extreme northeast zones I and II have an indistinct boundary where they coalesce along the rim of the synclinorium. Six stratigraphic units are exposed totaling approximately 10,500 feet of metamorphic rocks. Small scale structural features include a foliation, and a lineation in the planes of the foliation. Minor folding reflects the trends of the major structures. There are randomly orient

  7. 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.

  8. Geology team

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Evaluating of the combined utility of narrowband and multispectral imaging in both the infrared and visible for the lithologic identification of geologic materials, and of the combined utility of multispectral imaging in the visible and infrared for lithologic mapping on a global bases are near term recommendations for future imaging capabilities. Long term recommendations include laboratory research into methods of field sampling and theoretical models of microscale mixing. The utility of improved spatial and spectral resolutions and radiometric sensitivity is also suggested for the long term. Geobotanical remote sensing research should be conducted to (1) separate geological and botanical spectral signatures in individual picture elements; (2) study geobotanical correlations that more fully simulate natural conditions; and use test sites designed to test specific geobotanical hypotheses.

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

    USGS Publications Warehouse

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

    2004-01-01

    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

  10. Geology of the area adjacent to the Free Enterprise uranium-silver Mine, Boulder District, Jefferson County, Montana

    USGS Publications Warehouse

    Roberts, W.A.; Gude, A.J.

    1952-01-01

    Uranium minerals.occur in pods associated with cryptocrystalline silica, silver minerals, and scattered sulfide mineral grains in a hydrothermal vein that cuts quartz monzonite and alaskite at the Free Enterprise mine, 2 miles west of Boulder, Mont. The Free Enterprise vein is one of many silicified reef-like structures in this area, most of which trend about N. 60° E. The cryptocrystalline silica zones of the area are lenticular and are bordered by an altered zone where quartz monzonite is the wall rock. No alteration was noticed where alaskite is adjacent to silica zones. No uranium minerals were observed at the surface, but radioactivity anomalies were noted at 57 outcrops. Underground mining has shown that leaching by downward percolating waters has removed most of the uranium from the near-surface part of the Free Enterprise vein and probably has enriched slightly, parts of the vein and the adjacent wall rock from the bottom of the leached zone to the ground-water level. It is possible that other veins that show low to moderate radioactivity at the surface may contain significant concentrations of uranium minerals at relatively shallow depth. The quartz monzonite appears to be a more favorable host rock for the cryptocrystalline silica and associated uranium minerals than the alaskite. The alaskite occurs as vertical_dikes plug-like masses, and as irregularly shaped, gently dipping masses that are believed to have been intruded into open fractures formed during the cooling of the quartz monzonite.

  11. Geologic mapping of the air intake shaft at the Waste Isolation Pilot Plant

    SciTech Connect

    Holt, R.M.; Powers, D.W. )

    1990-12-01

    The air intake shaft (AS) was geologically mapped from the surface to the Waste Isolation Pilot Plant (WIPP) facility horizon. The entire shaft section including the Mescalero Caliche, Gatuna Formation, Santa Rosa Formation, Dewey Lake Redbeds, Rustler Formation, and Salado Formation was geologically described. The air intake shaft (AS) at the Waste Isolation Pilot Plant (WIPP) site was constructed to provide a pathway for fresh air into the underground repository and maintain the desired pressure balances for proper underground ventilation. It was up-reamed to minimize construction-related damage to the wall rock. The upper portion of the shaft was lined with slip-formed concrete, while the lower part of the shaft, from approximately 903 ft below top of concrete at the surface, was unlined. As part of WIPP site characterization activities, the AS was geologically mapped. The shaft construction method, up-reaming, created a nearly ideal surface for geologic description. Small-scale textures usually best seen on slabbed core were easily distinguished on the shaft wall, while larger scale textures not generally revealed in core were well displayed. During the mapping, newly recognized textures were interpreted in order to refine depositional and post-depositional models of the units mapped. The objectives of the geologic mapping were to: (1) provide confirmation and documentation of strata overlying the WIPP facility horizon; (2) provide detailed information of the geologic conditions in strata critical to repository sealing and operations; (3) provide technical basis for field adjustments and modification of key and aquifer seal design, based upon the observed geology; (4) provide geological data for the selection of instrument borehole locations; (5) and characterize the geology at geomechanical instrument locations to assist in data interpretation. 40 refs., 27 figs., 1 tab.

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

    USGS Publications Warehouse

    Taylor, Cliff D.; Johnson, Craig A.

    2010-01-01

    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

  13. Geologic nozzles

    USGS Publications Warehouse

    Werner, Kieffer S.

    1989-01-01

    The importance of the low characteristic velocities of geologic fluids has not been widely recognized, and as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the geyser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, the channel is constricted into the shape of a converging-diverging nozzle by the debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. -from Author

  14. Infrared spectral identification of metasomatic alteration minerals and its implication to gold exploration in Shihu Gold Deposit, Hebei Province, P.R. China

    NASA Astrophysics Data System (ADS)

    Liu, Jiacheng; Yao, Yuzeng; Wang, Yingpeng; Yuan, Zhou

    2014-11-01

    Hydrothermal alteration is of great importance for mineral exploration, especially the blind ore-hunting due to its larger scale and special zonation compared to the ore bodies. Infrared spectral identification of metasomatic alteration minerals can be done with little or no sample preparation and quantitative result can be obtained. In this paper, 65 wall-rock samples of several horizontal and vertical profiles were selected from Shihu Gold deposit in Hebei Province to do reflectance spectrum measurements by means of rough surface, smooth section and powder with portable ASD FieldSpec®3 spectrometer. ViewspecPro software was used to preprocess the spectrum, and metasomatic alteration minerals were spectrally discriminated by SII (Spectral International Inc) Specmin software package with wavelength of 1100~2500nm. The results shows that: (1) among all the three spectral libraries embedded in SPECMIN software, i.e., ASD, USGS and JPL, ASD spectral library is more suitable for the spectral hydrothermal alteration minerals identification in Shihu Gold Deposit; (2) the observed mineral zonation from wall-rock gneiss to ore-body indicates obvious downtrend of amphibole, chlorite, sericite, carbonate and barite, which is consistent with the microscopic and XRD results; (3) spectral identification of metasomatic alteration minerals is theoretically feasible, which is economic and convenient, and most important of all, the result can be quantitative or semi-quantitative. The results are helpful and successfully applied to the further mineral exploration in Shihu Gold Deposit.

  15. Marine Geology

    NASA Astrophysics Data System (ADS)

    van Andel, Tjeerd H.

    Marine geology was blessed early, about 30 years ago, with two great textbooks, one by P.H. Kuenen, the other by Francis P. Shepard, but in more recent years, no one has dared synthesize a field that has become so diverse and is growing so rapidly. There are many texts written for the beginning undergraduate student, mostly by marine geologists, but none can be handed conveniently to a serious advanced student or given to a colleague interested in what the field has wrought. The reason for this regrettable state is obvious; only an active, major scholar could hope to write such a book well, but the years would pass, his students dwindle, his grants vanish. He himself might be out of date before his book was. Kennett has earned a large measure of gratitude for his attempt to undertake this task. His personal price must have been high but so are our rewards.

  16. Geology of the Göçükdibi Cu-Pb-Zn Mineralization, Gökçedoǧan, Çorum (Turkey): Preliminary Findings on Its Formation

    NASA Astrophysics Data System (ADS)

    Yalçin, Cihan; Hanilçi, Nurullah; Kumral, Mustafa; Abdelnasser, Amr

    2016-04-01

    Göçükdibi Cu-Pb-Zn mineralization is located 3 km north west of Gökçedoǧan village where is 30 km east of the Kargı, Çorum. The geology of the mineralization area is represented by Mesozoic and Upper Pliocene lithostratigraphic units in different origin. These units with respect to their structural locations have identified as autochthonous and allachtonous. The autochthonous units which are the basement of the region are represented by Bekirli Metamorphites (Triassic-Liassic) and Beşpınar formation (Upper Cretaceous-Lower Eocene) which overlies the Bekirli Metamorphites as angular discordance. The allachtonous units are represented by Saraycık formation belongs to Kargı Ophioltic Melange, and located on the autochthonous units as tectonically. These allocthonous units are the product of the Neotethyan Ocean. The autochthonous and allachtonous units are overlaid by Upper Pliocene Ilgaz Formation and Plio-Quaternary stream sediments. The Cu-Pb-Zn mineralization is located in northwest of the Gökçedoǧan village within the Bekirli Metamorphites. The ore zone has N80E direction, 5 m wide and 120 m in length. The mineralizations which follow NE-SW trending structural line occurred as alternation with quartz-chlorite schists of the Bekirli Metamorphites. The mineralization is generally concordant to the foliation of schist's and also occurred as disseminated in the wall rocks. The ore paragenesis comprises with pyrite, chalcopyrite, sphalerite and galenit as the main sulphide minerals, and the malachite, azurite and limonite as the production of the oxidation. Preliminary data such as relationship between the ore and host rock, inner-structure of the ore and indicate that the Gökçedoǧan Cu-Pb-Zn mineralization was likely to have originated syngenetic. In addition, the geochemical behaviour of rare earth elements (REE) of the altered and mineralized samples collected from the alteration zone show that light REE enrichment with fair depletion of heavy REE

  17. Geologic Map of the Estes Park 30' x 60' Quadrangle, North-Central Colorado

    USGS Publications Warehouse

    Cole, James C.; Braddock, William A.

    2009-01-01

    The rocks and landforms of the Estes Park 30 x 60 minute quadrangle display an exceptionally complete record of geologic history in the northern Front Range of Colorado. The Proterozoic basement rocks exposed in the core of the range preserve evidence of Paleoproterozoic marine sedimentation, volcanism, and regional soft-sediment deformation, followed by regional folding and gradational metamorphism. The metasedimentary rocks of the Estes Park quadrangle are distinct within northern Colorado for preserving the complete metamorphic zonation from low-grade chlorite-muscovite phyllites, through middle greenschist-grade rocks with sequential aluminous porphyroblasts, to partially melted gneisses that contain high-grade cordierite and garnet in the non-melted residues. Regional and textural evidence shows that the widespread metamorphism was essentially concurrent with intrusion of the Boulder Creek Granodiorite and related magmas and with the peak of deformation in the partially melted high-grade rocks. The metamorphic thermal pulse arrived later following the peak of deformation in the physically higher, cooler, low-grade terrane. Mesoproterozoic time was marked by intrusion of biotite granite in the Longs Peak-St Vrain batholith, a complex, irregular body that occupies nearly half of the core of the Front Range in this quadrangle. The magma was dry and viscous as it invaded the metamorphic rocks and caused wholesale plastic folding of the wall rock structure. Steep metamorphic foliation that resulted from the Paleoproterozoic deformations was bowed upward and re-oriented into flat-lying attitudes as the crystal-rich magma rose buoyantly and spread out in the middle crust. Magma invaded the schists and gneisses along weak foliation planes and produced a characteristic sill-upon-sill intrusive fabric, particularly in the higher parts of the batholith. Broad, open arches and swales that are defined by the flow-aligned feldspar foliation of the granite, as well as by

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

    USGS Publications Warehouse

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

    1993-01-01

    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

  19. Old Geology and New Geology

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 28 May 2003

    Mangala Vallis one of the large outflow channels that channeled large quantities of water into the northern lowlands, long ago on geological timescales. This valley is one of the few in the southern hemisphere, as well as one of the few west of the Tharsis bulge. A closer look at the channel shows more recent weathering of the old water channel: the walls of the channel show small, dark slope streaks that form in dusty areas; and much of the surrounding terrain has subtle linear markings trending from the upper left to the lower right, which are probably features sculpted and streamlined by the wind. Geology still shapes the surface of Mars today, but its methods over the eons have changed.

    Image information: VIS instrument. Latitude -6, Longitude 209.6 East (150.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in

  20. Geologic investigations

    SciTech Connect

    Orkild, P.P.; Baldwin, M.J.; Townsend, D.R.

    1983-12-31

    The Climax stock is a composite granitic intrusive of Cretaceous age, composed of quartz monzonite and granodiorite, which intrudes rocks of Paleozoic and Precambrian age. Tertiary volcanic rocks, consisting of ash-flow and ash-fall tuffs, and tuffaceous sedimentary rocks overlie the sedimentary rocks and the stock. Erosion has removed much of the Tertiary volcanic rocks. Hydrothermal alteration of quartz monzonite and granodiorite is found mainly along joints and faults and varies from location to location. The Paleozoic carbonate rocks have been thermally and metasomatically altered to marble and tactite as much as 457 m (1500 ft) from the contact with the stock, although minor discontinuous metasomatic effects are noted in all rocks out to 914 m (3000 ft). Three major faults which define the Climax area structurally are the Tippinip, Boundary and Yucca faults. North of the junction of the Boundary and Yucca faults, the faults are collectively referred to as the Butte fault. The dominant joint sets and their average attitudes are N 32{degrees} W, 22{degrees} NE; N 60{degrees} W, vertical and N 35{degrees} E, vertical. Joints in outcrop are weathered and generally open, but in subsurface, the joints are commonly filled and healed with secondary minerals. 12 refs., 6 figs., 1 tab.

  1. Geologic Technician New Curriculum

    ERIC Educational Resources Information Center

    Karp, Stanley E.

    1970-01-01

    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)

  2. Geology of Kilauea volcano

    SciTech Connect

    Moore, R.B. . Federal Center); Trusdell, F.A. . Hawaiian Volcano Observatory)

    1993-08-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower east rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. 71 refs., 2 figs.

  3. Geology of kilauea volcano

    USGS Publications Warehouse

    Moore, R.B.; Trusdell, F.A.

    1993-01-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower cast rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. ?? 1993.

  4. K-Ar ages on intrusive and altered zones in the Chignik and Sutwik Island quadrangles: A section in The United States Geological Survey in Alaska: Accomplishments during 1979

    USGS Publications Warehouse

    Wilson, Frederic H.

    1981-01-01

    Continued K-Ar dating of intrusive rocks and hydrothermal alteration zones in the Chignik and Sutwik Island quadrangles of the Alaska Peninsula, supplemental to that by Wilson, Detterman, and Silberman (1978) and Wilson (1978), has refined our knowledge of the ages of the igneous rocks and clarified relations between altered zones and igneous events in the area.

  5. Co2 geological sequestration

    SciTech Connect

    Xu, Tianfu

    2004-11-18

    Human activities are increasingly altering the Earth's climate. A particular concern is that atmospheric concentrations of carbon dioxide (CO{sub 2}) may be rising fast because of increased industrialization. CO{sub 2} is a so-called ''greenhouse gas'' that traps infrared radiation and may contribute to global warming. Scientists project that greenhouse gases such as CO{sub 2} will make the arctic warmer, which would melt glaciers and raise sea levels. Evidence suggests that climate change may already have begun to affect ecosystems and wildlife around the world. Some animal species are moving from one habitat to another to adapt to warmer temperatures. Future warming is likely to exceed the ability of many species to migrate or adjust. Human production of CO{sub 2} from fossil fuels (such as at coal-fired power plants) is not likely to slow down soon. It is urgent to find somewhere besides the atmosphere to put these increased levels of CO{sub 2}. Sequestration in the ocean and in soils and forests are possibilities, but another option, sequestration in geological formations, may also be an important solution. Such formations could include depleted oil and gas reservoirs, unmineable coal seams, and deep saline aquifers. In many cases, injection of CO2 into a geological formation can enhance the recovery of hydrocarbons, providing value-added byproducts that can offset the cost of CO{sub 2} capture and sequestration. Before CO{sub 2} gas can be sequestered from power plants and other point sources, it must be captured. CO{sub 2} is also routinely separated and captured as a by-product from industrial processes such as synthetic ammonia production, H{sub 2} production, and limestone calcination. Then CO{sub 2} must be compressed into liquid form and transported to the geological sequestration site. Many power plants and other large emitters of CO{sub 2} are located near geological formations that are amenable to CO{sub 2} sequestration.

  6. The Geology of Vesta

    NASA Astrophysics Data System (ADS)

    Jaumann, R.; Russell, C. T.; Raymond, C. A.; Pieters, C. M.; Yingst, R. A.; Williams, D. A.; Buczkowski, D. L.; Krohn, K.; Otto, K.; Stephan, K.; DeSanctis, M. C.; Garry, W. B.; Blewett, D.

    2013-09-01

    The Dawn spacecraft collected over 28,000 images and a wealth of spectral data of Vesta's surface. These data enable analysis of Vesta's diverse geology including impact craters of all sizes and unusual shapes, a variety of ejecta blankets, large troughs, impact basins, enigmatic dark material, and considerable evidence for mass wasting and surface alteration processes [1,2,3]. Two large impact basins, Veneneia underlying the larger Rheasilvia basin dominate the south polar region [1,4]. The depression surrounding Vesta's south pole was formed by two giant impacts about one billion and two billion years ago [4,5]. Vesta's global tectonic patterns (two distinct sets of large troughs orthogonal to the axes of the impacts) strongly correlate with the locations of the two south polar impact basins, and were likely created by their formation [1,6]. Numerous unusual asymmetric impact craters and ejecta indicate the strong influence of topographic slope in cratering on Vesta [1]. One type of gully in crater walls is interpreted to form by dry granular flow, but another type is consistent with transient water flow [7]. Very steep topographic slopes near to the angle of repose are common; slope failures make resurfacing due to impacts and their associated gravitational slumping and seismic effects an important geologic process on Vesta [1]. Clusters of pits in combination with impact melt [8] suggest the presence of volatile materials underlying that melt in some crater floors. Relatively dark material of uncertain origin is intermixed in the regolith layers and partially excavated by younger impacts yielding dark outcrops, rays and ejecta [1,9]. Vesta's surface is reworked by intense impacts and thus much younger than the formation of its crust [2,5].

  7. Lunar Field Geological Interpretations Assisted by LROC, Mini-RF and M3: Taurus-Littrow

    NASA Astrophysics Data System (ADS)

    Schmitt, H. H.; Petro, N. E.; Robinson, M. S.; Wells, R.; Weiss, B. P.; Mercer, C. M.

    2015-12-01

    Integration of Apollo 17 field observations and photographs, sample investigations, Lunar Reconnaissance Orbiter Camera images, Moon Mineralogical Mapper data, and Mini-RF images provides new insights into the geology of the valley of Taurus Littrow. Samples from the North Massif and the Sculptured Hills appear to represent a stratigraphic sequence of ejecta from the Cranium and Serenitatis basin-forming events. Published analyses of these samples provide the approximate ages for those events that appear consistent with this sequence; however, within current 2 sigma error limits, these ages overlap. Strong evidence exists that the Sculptured Hills physiographic unit consists of Imbrium ejecta made up of a layered, Mg-suite pluton. Rim boulders at Camelot Crater constitute wall rocks of the crater rather than ejecta and provide a potential opportunity for investigations of remnant magnetic field orientation at the time of the eruption of late mare basalt lavas in the valley. A second and older light mantle avalanche deposit has been identified, and the origin, potential fluidized flow mechanisms, and geology of the two avalanches from the South Massif have been clarified, including the probability of significant agitation heating during flow. The structure, potential effects, and timing of the Lee-Lincoln thrust fault, and of an ancillary fault revealed by radar, have been defined and raise doubts about the association of the light mantle avalanche with secondary impacts related to the Tycho event.

  8. Structural evolution of the Chugach-Prince William terrane at the hinge of the orocline in Prince William Sound, and implications for ore deposits: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1992

    USGS Publications Warehouse

    Haeussler, Peter J.; Nelson, Steven W.

    1993-01-01

    The Chugach-Prince William terrane is a Mesozoic through Tertiary accretionary complex that lies along coastal southern and southeastern Alaska. In Prince William Sound, the regional structural fabric bends about 90°, forming an orocline. Rocks at the hinge of the orocline consist of turbidites, conglomerate, and minor volcanic rocks and limestone. The structural geology in the hinge region defines a number of domains (each >15 km2) consisting of kilometer-scale tight folds. Adjacent domains may have up to a 90° difference in the strike of bedding and trend of fold axes. Four granite to tonalitic or gabbro plutons are dated or inferred to be about 35 Main age, and all were emplaced after regional folding. Base-metal sulfide mineral occurrences, barren quartz veins, and strikeslip late faults locally cut the plutons and generally strike north-south. The mineral occurrences often have a dendritic network of quartz veinlets adjacent to the mineralized zone and brecciated wall rock within the zone. Oroclinal bending, in the style of bending a bar, is consistent with the origin of the complicated domainal geometry of the structures. The Contact fault, thought by some workers to juxtapose two parts of the accretionary prism, truncates one of these 35-Ma plutons with strike-slip offset, but previous reverse motion cannot be ruled out. A magmatic source for the ore-forming fluids is consistent with the structural and mineralogical data. The north-south orientation of mineralized zones suggests that east-west extension occurred possibly during release of fluids from the plutons, which locally hydrofractured the wall rocks and allowed migration of ore-forming fluids along preexisting fractures.

  9. Geophysics & Geology Inspected.

    ERIC Educational Resources Information Center

    Neale, E. R. W.

    1981-01-01

    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)

  10. Historical sketch: Radar geology

    NASA Technical Reports Server (NTRS)

    Macdonald, H.

    1980-01-01

    A chronological assessment is given of the broad spectra of technology associated with radar geology. Particular attention is given to the most recent developments made in the areas of microwave Earth resources applications and geologic remote sensing from aircraft and satellite. The significance of space derived radar in geologic investigations is discussed and the scientific basis for exploiting the sensitivity of radar signals to various aspects of geologic terrain is given.

  11. Geological Survey research 1978

    USGS Publications Warehouse

    ,

    1978-01-01

    This U.S. Geological Survey activities report includes a summary of 1978 fiscal year scientific and economic results accompanied by a list of geologic and hydrologic investigations in progress and a report on the status of topographic mapping. The summary of results includes: (1) Mineral and water resources, (2) Engineering geology and hydrology, (3) Regional geology, (4) Principles and processes, (5) Laboratory and field methods, (6) Topographic surveys and mapping, (7) Management of resources on public lands, (8) Land information and analysis, and (9) Investigations in other countries. Also included are lists of cooperating agencies and Geological Survey offices. (Woodard-USGS)

  12. Geological Survey research 1976

    USGS Publications Warehouse

    ,

    1976-01-01

    This U.S. Geological Survey activities report includes a summary of recent (1976 fiscal year) scientific and economic results accompanied by a list of geologic and hydrologic investigations in progress and a report on the status of topographic mapping. The summary of results includes: (1) Mineral resources, Water resources, (2) Engineering geology and hydrology, (3) Regional geology, (4) Principles and processes, (5) Laboratory and field methods, (6) Topographic surveys and mapping, (7) Management of resources on public lands, (8) Land information and analysis, and (9) Investigations in other countries. Also included are lists of cooperating agencies and Geological Survey offices. (Woodard-USGS)

  13. Hydromechanical coupling in geologic processes

    USGS Publications Warehouse

    Neuzil, C.E.

    2003-01-01

    Earth's porous crust and the fluids within it are intimately linked through their mechanical effects on each other. This paper presents an overview of such "hydromechanical" coupling and examines current understanding of its role in geologic processes. An outline of the theory of hydromechanics and rheological models for geologic deformation is included to place various analytical approaches in proper context and to provide an introduction to this broad topic for nonspecialists. Effects of hydromechanical coupling are ubiquitous in geology, and can be local and short-lived or regional and very long-lived. Phenomena such as deposition and erosion, tectonism, seismicity, earth tides, and barometric loading produce strains that tend to alter fluid pressure. Resulting pressure perturbations can be dramatic, and many so-called "anomalous" pressures appear to have been created in this manner. The effects of fluid pressure on crustal mechanics are also profound. Geologic media deform and fail largely in response to effective stress, or total stress minus fluid pressure. As a result, fluid pressures control compaction, decompaction, and other types of deformation, as well as jointing, shear failure, and shear slippage, including events that generate earthquakes. By controlling deformation and failure, fluid pressures also regulate states of stress in the upper crust. Advances in the last 80 years, including theories of consolidation, transient groundwater flow, and poroelasticity, have been synthesized into a reasonably complete conceptual framework for understanding and describing hydromechanical coupling. Full coupling in two or three dimensions is described using force balance equations for deformation coupled with a mass conservation equation for fluid flow. Fully coupled analyses allow hypothesis testing and conceptual model development. However, rigorous application of full coupling is often difficult because (1) the rheological behavior of geologic media is complex

  14. Forensic geology exhumed

    NASA Astrophysics Data System (ADS)

    Martinez, Joseph Didier

    Forensic geology binds applied geology to the world of legal controversy and action. However, the term “forensic” is often misconstrued. Although even some attorneys apply it only to the marshalling of evidence in criminal cases, it has a much broader definition. One dictionary defines it as “pertaining to, connected with, or used in courts of law or public discussion and debate.” The American Geological Institute's Glossary of Geology defines forensic geology as “the application of the Earth sciences to the law.” The cited reference to Murray and Tedrow [1975], however, deals mostly if not exclusively with the gathering and use of evidence in criminal cases, despite the widespread involvement of geologists in more general legal matters. It seems appropriate to “exhume” geology's wider application to the law, which is encompassed by forensic geology.

  15. Alaska geology revealed

    USGS Publications Warehouse

    Wilson, Frederic H.; Labay, Keith A.

    2016-11-09

    This map shows the generalized geology of Alaska, which helps us to understand where potential mineral deposits and energy resources might be found, define ecosystems, and ultimately, teach us about the earth history of the State. Rock units are grouped in very broad categories on the basis of age and general rock type. A much more detailed and fully referenced presentation of the geology of Alaska is available in the Geologic Map of Alaska (http://dx.doi.org/10.3133/sim3340). This product represents the simplification of thousands of individual rock units into just 39 broad groups. Even with this generalization, the sheer complexity of Alaskan geology remains evident.

  16. Geological Survey research 1981

    USGS Publications Warehouse

    ,

    1982-01-01

    This U.S. Geological Survey activities report includes a summary of 1981 fiscal year scientific and economic results accompanied by a list of geologic, hydrologic, and cartographic investigations in progress. The summary of results includes: (1) Mineral, (2) Water resources, (3) Engineering geology and hydrology, (4) Regional geology, (5) Principles and processes, (6) Laboratory and field methods, (7) Topographic surveys and mapping, (8) Management of resources on public lands, (9) Land information and analysis, and (10) Investigations in other countries. Also included are lists of investigations in progress.

  17. Advances in planetary geology

    NASA Technical Reports Server (NTRS)

    Woronow, A. (Editor)

    1981-01-01

    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.

  18. Glossary of geology

    SciTech Connect

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

    1987-01-01

    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.

  19. People and Geology.

    ERIC Educational Resources Information Center

    Naturescope, 1987

    1987-01-01

    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.…

  20. Advances in Planetary Geology

    NASA Technical Reports Server (NTRS)

    Woronow, A. (Editor)

    1982-01-01

    Advances in Planetary Geology is a new series intended to serve the planetary geology community with a form for quick and thorough communications. There are no set lists of acceptable topics or formats, and submitted manuscripts will not undergo a formal review. All submissions should be in a camera ready form, preferably spaced, and submitted to the editor.

  1. Radiometric Dating in Geology.

    ERIC Educational Resources Information Center

    Pankhurst, R. J.

    1980-01-01

    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)

  2. Geology of the Caribbean.

    ERIC Educational Resources Information Center

    Dillon, William P.; And Others

    1988-01-01

    Describes some of the geologic characteristics of the Caribbean region. Discusses the use of some new techniques, including broad-range swath imaging of the sea floor that produces photograph-like images, and satellite measurement of crustal movements, which may help to explain the complex geology of the region. (TW)

  3. Field Geology/Processes

    NASA Technical Reports Server (NTRS)

    Allen, Carlton; Jakes, Petr; Jaumann, Ralf; Marshall, John; Moses, Stewart; Ryder, Graham; Saunders, Stephen; Singer, Robert

    1996-01-01

    The field geology/process group examined the basic operations of a terrestrial field geologist and the manner in which these operations could be transferred to a planetary lander. Four basic requirements for robotic field geology were determined: geologic content; surface vision; mobility; and manipulation. Geologic content requires a combination of orbital and descent imaging. Surface vision requirements include range, resolution, stereo, and multispectral imaging. The minimum mobility for useful field geology depends on the scale of orbital imagery. Manipulation requirements include exposing unweathered surfaces, screening samples, and bringing samples in contact with analytical instruments. To support these requirements, several advanced capabilities for future development are recommended. Capabilities include near-infrared reflectance spectroscopy, hyper-spectral imaging, multispectral microscopy, artificial intelligence in support of imaging, x ray diffraction, x ray fluorescence, and rock chipping.

  4. Geology and geochemistry of the Mendejin plutonicrocks, Mianeh, Iran

    NASA Astrophysics Data System (ADS)

    Somarin, A. Karimzadeh

    2006-10-01

    The Mendejin pluton is located in the Mianeh area, NW Iran, 550 km from Tehran. This pluton is probably of Oligo-Miocene age and is the result of extensive magmatism which occurred during and after the Alpine Orogeny. Similar plutons are common in the Alborz-Azarbaijan structural zone of Iran, and it is likely that there are concealed plutons related to this extensive Cenozoic magmatism, but due to their youth and low rates of erosion they have not yet been exposed. The Mendejin pluton is a composite body made up of four types of plutonic rocks: pink tonalite, grey tonalite, diorite and aplite. The pink tonalite is porphyritic and contains phenocrysts of plagioclase, K-feldspar and hornblende in a groundmass consisting of quartz, plagioclase, K-feldspar, hornblende, zircon, monazite, leucoxene, apatite and hematite. The grey porphyritic tonalite has more biotite, pyroxene and pyrite and less accessory phases compared with the pink tonalite. The diorite has a microporphyritic texture with phenocrysts of plagioclase, hornblende and augite. This rock also occurs as xenoliths in the Mendejin pluton. The aplitic dykes are the youngest magmatic products at Mendejin. The Mendejin tonalite contains more Cl, As, S, Cu, Ni and Zn than the global granite. These rocks are of I-type, peraluminous and calc-alkaline, with medium to high potassium, and were formed as part of a volcanic arc. The Mendejin pluton contains up to 8 ppb gold and could potentially have been the source of an economic gold deposit by leaching of Au from wall rocks and deposition in extensive hydrothermally altered marginal zones.

  5. Geologic Map of Nevada

    USGS Publications Warehouse

    Crafford, A. Elizabeth Jones

    2007-01-01

    The purpose of the Geologic Map of Nevada is to provide an integrated set of digital geologic information that can be used for regional geologic and rigorous spatial analysis. Two components of this map represent new information that has not been published in this form before. The new geology layer was created by merging into a single file individual digital Nevada county geologic maps (Hess and Johnson, 1997), published at a scale of 1:250,000. A new regional interpretation was created to unify all of the different county rock units, and then appropriate edits and modifications were made to the file to reflect additional geologic information and more current geologic interpretations. All possible sources of information were not utilized in the scope of this project, but rather the goal was to create a consistent Statewide 1:250,000-scale map that would facilitate regional geologic interpretation and be a foundation for future spatial analyses of digital data. Secondly, a new database of conodont biostratigraphic data compiled and analyzed by Anita Harris is also incorporated into the map. Information about many, but not all, of these conodont samples have been published separately elsewhere over the years, but they have not been presented together in a single digital database. Other previously published data layers are used in this map to enhance the usefulness of the geologic information. These layers include mineral deposit locations, oil well locations, and cartographic layers such as county boundaries, roads, towns, cities, rivers, water bodies, township, range and section grids, quadrangle grids, and topography. A summary of these components is given below, and complete descriptions of each layer are provided in the digital metadata.

  6. Essential Elements of Geologic Reports.

    ERIC Educational Resources Information Center

    Webb, Elmer James

    1988-01-01

    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)

  7. Geology of caves

    USGS Publications Warehouse

    Morgan, I.M.

    1991-01-01

    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.

  8. Formation evaluation: Geological procedures

    SciTech Connect

    Whittaker, A.

    1985-01-01

    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.

  9. Deterministic geologic processes and stochastic modeling

    SciTech Connect

    Rautman, C.A.; Flint, A.L.

    1991-12-31

    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.

  10. Scaling the Geologic Past

    ERIC Educational Resources Information Center

    Gerritts, Mary

    1975-01-01

    Describes construction of a Geologic Time Scale on a 100 foot roll of paper and suggests activities concerning its use. Includes information about fossils and suggestions for conducting a fossil field trip with students. (BR)

  11. Economic Geology (Oil & Gas)

    ERIC Educational Resources Information Center

    Geotimes, 1972

    1972-01-01

    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)

  12. Advances in Planetary Geology

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    The surface of Mars displays a broad range of channel and valley features. There is as great a range in morphology as in scale. Some of the features of Martian geography are examined. Geomorphic mapping, crater counts on selected surfaces, and a detailed study of drainage basins are used to trace the geologic evolution of the Margaritifer Sinus Quandrangle. The layered deposits in the Valles Marineris are described in detail and the geologic processes that could have led to their formation are analyzed.

  13. Geologic exploration of Mars

    NASA Technical Reports Server (NTRS)

    Plescia, J. B.

    1990-01-01

    The scientific objectives and methods involved in a geologic exploration of Mars from a manned outpost are discussed. The constraints on outpost activities imposed by the limited crew size, limited amount of time available for science, the limited diversity of scientific expertise, and the competition between scientific disciplines are addressed. Three examples of possible outpost locations are examined: the Olympus Mons aureole, Mangala Valles/Daedalia Planum, and Candor Chasma. The geologic work that could be done at each site is pointed out.

  14. Geology of the Mother Load gold belt and adjacent foothills metamorphic belt, California

    SciTech Connect

    Landefeld, L.A.

    1985-01-01

    The late Jurassic Mother Lode gold-quartz vein system south of the Consumnes River is hosted by portions of 1) a submarine volcanic arc and overlying epiclastic basin, and 2) the ultramafic-mafic plutonic subarc basement. During accretion to the Paleozoic shelf of western North America, the subarc basement tectonically intruded the disrupted arc basin, incorporating hanging wall lithologies to produce the tectonic melange of the Melones fault zone (MFZ). Late orogenic dikes intrude the margins of the MFZ and adjacent wall rocks. These dikes were altered during the gold-quartz vein formation. The proximal to medial volcanic strata are, from oldest to youngest: 1) island arc tholeiitic pillow basalts, 2) a thin radiolarian chert bed grading into 3) a submarine volcaniclastic sequence, and 4) sporadically distributed flows of calc-alkaline basalt through boninite. Cessation of volcanic activity is marked by the deposition of an organic carbon-rich epiclastic sequence. The intensely folded strata in JT rocks east of the MFZ may be basinward lateral equivalents of the JT strata west of the MFZ. Differences in style of deformation and metamorphic rank in the strata are typical of vertical and lateral variations in basins where one part is passive and another part is tectonically active as the basin closes.

  15. Geology at Yucca Mountain

    SciTech Connect

    1993-05-01

    Both advocates and critics disagree on the significance and interpretation of critical geological features which bear on the safety and suitability of Yucca Mountain as a site for the construction of a high-level radioactive waste repository. Critics believe that there is sufficient geological evidence to rule the site unsuitable for further investigation. Some advocates claim that there is insufficient data and that investigations are incomplete, while others claim that the site is free of major obstacles. We have expanded our efforts to include both the critical evaluations of existing geological and geochemical data and the collection of field data and samples for the purpose of preparing scientific papers for submittal to journals. Summaries of the critical reviews are presented in this paper.

  16. Geologic map of Mars

    USGS Publications Warehouse

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

    2014-01-01

    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.

  17. Geological fakes and frauds

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    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.

  18. Geological Corrections in Gravimetry

    NASA Astrophysics Data System (ADS)

    Mikuška, J.; Marušiak, I.

    2015-12-01

    Applying corrections for the known geology to gravity data can be traced back into the first quarter of the 20th century. Later on, mostly in areas with sedimentary cover, at local and regional scales, the correction known as gravity stripping has been in use since the mid 1960s, provided that there was enough geological information. Stripping at regional to global scales became possible after releasing the CRUST 2.0 and later CRUST 1.0 models in the years 2000 and 2013, respectively. Especially the later model provides quite a new view on the relevant geometries and on the topographic and crustal densities as well as on the crust/mantle density contrast. Thus, the isostatic corrections, which have been often used in the past, can now be replaced by procedures working with an independent information interpreted primarily from seismic studies. We have developed software for performing geological corrections in space domain, based on a-priori geometry and density grids which can be of either rectangular or spherical/ellipsoidal types with cells of the shapes of rectangles, tesseroids or triangles. It enables us to calculate the required gravitational effects not only in the form of surface maps or profiles but, for instance, also along vertical lines, which can shed some additional light on the nature of the geological correction. The software can work at a variety of scales and considers the input information to an optional distance from the calculation point up to the antipodes. Our main objective is to treat geological correction as an alternative to accounting for the topography with varying densities since the bottoms of the topographic masses, namely the geoid or ellipsoid, generally do not represent geological boundaries. As well we would like to call attention to the possible distortions of the corrected gravity anomalies. This work was supported by the Slovak Research and Development Agency under the contract APVV-0827-12.

  19. Life on Guam: Geology.

    ERIC Educational Resources Information Center

    Elkins, Gail

    This unit is part of a series of materials produced by a project to develop locally applicable class, lab, and field materials in ecology and social studies for Guam junior and senior high schools. While the materials were designed for Guam, they can be adapted to other localities. This unit is designed to acquaint the students with the geology of…

  20. Glacial Geology of Wisconsin.

    ERIC Educational Resources Information Center

    Madison Public Schools, WI.

    This publication is a teacher's resource and guidebook for the presentation of the three filmstrips in the "Glacial Geology of Wisconsin" series. The first filmstrip is subtitled, "Evidence of the Glaciers," the second "How the Glaciers Reshaped the Landscape," and the third "Fossils of the Ice Age."…

  1. Geological impacts on nutrition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter reviews the nutritional roles of mineral elements, as part of a volume on health implications of geology. The chapter addresses the absorption and post-absorptive utilization of the nutritionally essential minerals, including their physiological functions and quantitative requirements....

  2. 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...

  3. Geological processes and evolution

    USGS Publications Warehouse

    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

    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.

  4. Advances in planetary geology

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A wide variety of topics on planetary geology are presented. Subjects include stratigraphy and geomorphology of Copernicus, the Mamers valle region, and other selected regions of Mars and the Moon. Crater density and distribution are discussed for Callisto and the lunar surface. Spectroscopic analysis is described for Europa and Ganymede.

  5. Geology of Wisconsin.

    ERIC Educational Resources Information Center

    Madison Public Schools, WI.

    Included are a teacher's guidebook and two filmstrips, "Geology of Wisconsin," and associated materials. The following are described: outline of objectives; suggested use of the filmstrips and guidebook; outline of the filmstrip content; four pages of illustrations suitable for duplication; a test for each filmstrip; and a list of…

  6. Geology: The Active Earth.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1987-01-01

    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…

  7. Geological Field Trip Guidebooks

    ERIC Educational Resources Information Center

    Wallace, Harriet E.

    1978-01-01

    Geological field trip guidebooks, developed for use during a field trip or field conference, are considered ephemeral publications by their compilers and publishers. Too few copies are printed and little attention is paid to bibliographic format and information. These difficulties are discussed and recommendations are made to alleviate the…

  8. Geologic controls on radon

    SciTech Connect

    Gates, A.E.; Gundersen, L.C.S.

    1992-01-01

    This text provides a review of recent research on geological controls of [sup 222]Rn concentrations in soil gas in relation to the problem of high indoor radon concentrations in houses. The importance of the subject matter is highlighted in the preface by the observation that the US Environmental Protection Agency (EPA) estimates that 15,000 to 25,000 deaths result from radon-induced lung cancer each year in the United States. The text contains 8 Chapters: (1) Geology of radon in the United States; (2) Sensitivity of soil radon to geology and the distribution of radon and uranium in the Hylas Zone Area, Virginia; (3) Geologic and environmental implications of high soil-gas radon concentrations in The Great Valley, Jefferson and Berkeley Counties, West Virginia; (4) Soil radon distribution in glaciated areas: an example from the New Jersey Highlands; (5) Radon in the coastal plain of Texas, Alabama, and New Jersey; (6) Effects of weather and soil characteristics on temporal variations in soil-gas radon concentrations; (7) A theoretical model for the flux of radon from rock to ground water; (8) The influence of season, bedrock, overburden, and house construction on airborne levels of radon in Maine homes. The individual chapters are written by different authors in the form of self-contained research papers, each of which is followed by a comprehensive list of references.

  9. Public perceptions of geology

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  10. Geologic provinces of Oklahoma

    SciTech Connect

    Northcutt, R.A.; Campbell, J.A.

    1995-09-01

    The geologic provinces of Oklahoma are mainly the product of tectonics and attendant sedimentation of Pennsylvanian age. Most boundaries are structural; thus, the provinces map is a generalized tectonic map. Permian and post-Paleozoic strata tend to mask those structures, but most of those strata have been removed by erosion, except in the Anadarko Basin and the Wichita Uplift provinces. The location of most of Oklahoma`s oil and gas resources are either influenced by, or are the direct result of Pennsylvanian tectonics and sedimentation patterns. Therefore, the present study also defines provinces in the subsurface on the basis of geological criteria. The authors have attempted to use the originally published names for the recognized provinces. However, we have also used the most geologically correct names, i.e., Nemaha Uplift, Nemaha Fault Zone, and Central Oklahoma Fault, in lieu of Nemaha {open_quotes}Ridge.{close_quotes} Oklahoma is separated into five major uplifts and five major basins. The Gulf Coastal Plain is not included in this study because it is a veneer of Cretaceous cover that masks significant structures. Faults are the most common boundary element. Although their precise age commonly is known only approximately, their geographic location is less controversial, except in detail. Stratigraphic/structural boundaries are based on less precise geological information. The major example of a surface stratigraphic/structural boundary is the southwestern limit of the Ozark Uplift in eastern Oklahoma. Stratigraphic/structural boundaries in the subsurface are commonly based on structural or isopachous contours from well or geophysical data, or on a structural trend, as well as the experience of the authors. Basement structure is preferred. An example is the boundary that separates the Marietta Basin from adjacent geologic elements.

  11. A geological explanation for intraplate earthquake clustering complexity: The zeolite-bearing fault/fracture networks in the Adamello Massif (Southern Italian Alps)

    NASA Astrophysics Data System (ADS)

    Dempsey, E. D.; Holdsworth, R. E.; Imber, J.; Bistacchi, A.; Di Toro, G.

    2014-09-01

    Interconnected networks of faults and veins filled with hydrothermal minerals such as zeolite are widespread in many orogenic terrains. These fractures commonly form at relatively low temperatures (e.g. <200 °C) late in the tectonic history and represent significant phases of fluid flow and mineralisation during exhumation. Zeolite-bearing fractures spatially associated with the Gole Larghe Fault Zone in the Southern Italian Alps are preserved along an interconnected network of variably orientated pre-existing structures. They show evidence of repeated episodes of hydraulic tensile fracturing and small magnitude (total offsets <5 m) shear displacements. We use geological observations and Coulomb stress modelling to propose that repeated seismogenic rupturing of larger offset faults led to local stress transfer and reactivation of widely distributed smaller pre-existing structures in the wall rocks. The differing orientations of the pre-existing features within what is assumed to have been a single regional stress field led to the simultaneous development of reverse, strike-slip and extensional faults. The kinematic diversity and cyclic nature of the hydraulically-assisted deformation suggest that the mineralised fracture systems represent a geological manifestation of intraplate micro-earthquake clusters associated with fluid migration episodes in the upper crust. Our observations highlight the role of crustal fluids and structural reactivation during earthquakes.

  12. Geologic map of Meridiani Planum, Mars

    USGS Publications Warehouse

    Hynek, Brian M.; Di Achille, Gaetano

    2017-01-31

    Introduction and BackgroundThe Meridiani Planum region of Mars—originally named due to its proximity to the Martian prime meridian—contains a variety of geologic units, including those that are crater‑related, that span the Early Noachian to Late Amazonian Epochs. Mars Global Surveyor (MGS) data indicate this area contains extensive layered deposits, some of which are rich in the mineral hematite. The National Aeronautics and Space Administration’s (NASA) Mars Exploration Rover (MER)  Opportunity  landed in Meridiani Planum in early 2004 and, at the time of this writing, is still conducting operations. A variety of water-altered bedrock outcrops have been studied and contain indications of prolonged surface and near-surface fluid/rock interactions. The purpose of this study is to use the more recent orbiter data to place the rover’s findings in a broader context by assessing the geologic and hydrologic histories of the region.

  13. Conversion of Geologic Quadrangle Maps to Geologic Coverages

    DTIC Science & Technology

    1994-01-01

    HARMON CREEK 30 NW WOOLWORTH 39 NW 8 Conversion of Geologic Guadrangle Maps to Geologic Coverages Table 1. Completed geologic coverages for Tennessee...40 WINDLE 19 WOLF PIT RIDGE 35 WOODBURY 22 WOOLWORTH 29 YOUNGVILLE 17 YUMA 78 NE 328 NE 19 SW 316 SW 43 NE 153 SE 305 SW 145 SW 307 SE

  14. Using Snow to Teach Geology.

    ERIC Educational Resources Information Center

    Roth, Charles

    1991-01-01

    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)

  15. Geologic Map Database of Texas

    USGS Publications Warehouse

    Stoeser, Douglas B.; Shock, Nancy; Green, Gregory N.; Dumonceaux, Gayle M.; Heran, William D.

    2005-01-01

    The purpose of this report is to release a digital geologic map database for the State of Texas. This database was compiled for the U.S. Geological Survey (USGS) Minerals Program, National Surveys and Analysis Project, whose goal is a nationwide assemblage of geologic, geochemical, geophysical, and other data. This release makes the geologic data from the Geologic Map of Texas available in digital format. Original clear film positives provided by the Texas Bureau of Economic Geology were photographically enlarged onto Mylar film. These films were scanned, georeferenced, digitized, and attributed by Geologic Data Systems (GDS), Inc., Denver, Colorado. Project oversight and quality control was the responsibility of the U.S. Geological Survey. ESRI ArcInfo coverages, AMLs, and shapefiles are provided.

  16. Geologic Mapping of V-19

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  17. Geology of California. Second Edition

    SciTech Connect

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

    1990-01-01

    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.

  18. Revisiting the Field Geology of Taurus-Littrow

    NASA Technical Reports Server (NTRS)

    Schmitt, H. H.; Petro, N. E.; Wells, R. A.; Robinson, M. S.; Weiss, B. P.; Mercer, C. M.

    2016-01-01

    Integration of Apollo 17 field observations and photographs, sample investigations, Lunar Reconnaissance Orbiter Camera images, Chandrayaan-1 Moon Mineralogy Mapper (M(sup 3)) spectra, and Miniature Radio Frequency (Mini-RF) S-band radar images provides new insights into the geology of the valley of Taurus-Littrow on the Moon. Connecting the various remote observations to sample data enables a set of new conclusions to be drawn regarding the geological evolution of the valley. Structural considerations and published and recalculated Ar-40/Ar-39 analyses of samples from the North Massif and the Sculptured Hills indicate that the Crisium basin formed about 3.93 Ga; the Serenitatis basin about 3.82 Ga; and the Imbrium basin no earlier than 3.82 Ga and no later than the average of 3.72 Ga for 33 age dates from samples of the valley's mare basalts. Strong evidence continues to support the conclusion of others (Lucchitta, 1972; Spudis et al., 2011; Fassett et al., 2012) that the Sculptured Hills physiographic unit consists of Imbrium ejecta. Interpretation of M(sup 3) spectral data and Apollo 17 samples indicate that rock units of the Sculptured Hills consist of a largely coherent, Mg-suite pluton. LROC NAC stereo images and Mini-RF data indicate the presence of several exposed pyroclastic fissures across the Sculptured Hills. Rim boulders at Camelot Crater constitute nearly in situ wall rocks of that crater rather than ejecta and provide an opportunity for investigations of remanent magnetic field orientation at the time of the eruption of late mare basalt lavas in the valley. Paleomagnetic field orientation information also may be obtained relative to melt-breccia contacts in North Massif boulders that suggest original horizontal orientations. LROC images indicate the existence of two temporally separate light mantle avalanche deposits. The origin, potential flow mechanisms, and geology of the youngest avalanche from the South Massif have been clarified. The existence

  19. Conference on Early Mars: Geologic and Hydrologic Evolution, Physical and Chemical Environments, and the Implications for Life

    NASA Technical Reports Server (NTRS)

    Clifford, S. M. (Editor); Treiman, A. H. (Editor); Newsom, H. E. (Editor); Farmer, J. D. (Editor)

    1997-01-01

    Topics considered include: Geology alteration and life in an extreme environment; developing a chemical code to identify magnetic biominerals; effect of impacts on early Martin geologic evolution; spectroscopic identification of minerals in Hematite-bearing soils and sediments; exopaleontology and the search for a Fossil record on Mars; geochemical evolution of the crust of Mars; geological evolution of the early earth;solar-wind-induced erosion of the Mars atmosphere. Also included geological evolution of the crust of Mars.

  20. Geology of the Caribbean

    USGS Publications Warehouse

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

    1987-01-01

    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

  1. Introduction to ore geology

    SciTech Connect

    Evans, A.M.

    1987-01-01

    This textbook on ore geology is for second and third year undergraduates and closely parallels the undergraduate course given in this subject at England's University of Leicester. The volume covers three major areas: (1) principles of ore geology, (2) examples of the most important types of ore deposits, and (3) mineralization in space and time. Many chapters have been thoroughly revised for this edition and a chapter on diamonds has been added. Chapters on greisen and pegmatite have also been added, the former in response to the changing situation in tin mining following the recent tin crisis, and the latter in response to suggestions from geologists in a number of overseas countries. Some chapters have been considerably expanded and new sections added, including disseminated gold deposits and unconformity-associated uranium deposits. The author also expands on the importance of viewing mineral deposits from an economic standpoint.

  2. Geological Survey research, 1975

    USGS Publications Warehouse

    ,

    1975-01-01

    'Geological Survey Research 1975 ' is the 16th annual synopsis of the results of U.S. Geological Survey investigations. These studies are largely directed toward the development of knowledge that will assist the Nation to use and conserve the land and its physical resources wisely. They are wide ranging in scope and deal with almost every facet of solid-earth science and fact finding. Many of the studies are continuations of investigations that have been in progress for several years. But others reflect the increased attention being given to problems that have assumed greater importance in recent years--problems relating to mineral fuels and mineral resources, water quality, environmental impact of mineral resources, land-use analysis, earthquake hazards reduction, subsidence, and the applications of LANDSAT data, to cite a few examples. (Woodard-USGS)

  3. 77 FR 19032 - Geological Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... No: 2012-7479] DEPARTMENT OF THE INTERIOR Geological Survey Announcement of National Geospatial Advisory Committee Meeting AGENCY: U.S. Geological Survey, Interior. ACTION: Notice of meeting. SUMMARY... Arista Maher at the U.S. Geological Survey (703-648-6283, amaher@usgs.gov ). Registrations are due...

  4. Environmental Trends in Geologic Education

    ERIC Educational Resources Information Center

    Pestrong, Raymond

    1970-01-01

    Considers strategies for developing college level introductory environmental geology courses, emphasizing relevance to local surroundings, Considers graduate studies in this field, but does not recommend the establishment of an environmental geology department at this time. Reviews the responsibilities the geology department has to the community…

  5. Geologic map of Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.; Hults, Chad P.; Mull, Charles G.; Karl, Susan M.

    2015-12-31

    This Alaska compilation is unique in that it is integrated with a rich database of information provided in the spatial datasets and standalone attribute databases. Within the spatial files every line and polygon is attributed to its original source; the references to these sources are contained in related tables, as well as in stand-alone tables. Additional attributes include typical lithology, geologic setting, and age range for the map units. Also included are tables of radiometric ages.

  6. Borehole geological assessment

    NASA Technical Reports Server (NTRS)

    Spuck, W. H., III (Inventor)

    1979-01-01

    A method and apparatus are discussed for performing geological assessments of a formation located along a borehole, and a boring tool that bores a pair of holes into the walls of the borehole and into the surrounding strata along with a pair of probes which are installed in the holes. One of the probes applies an input such as a current or pressured fluid, and the other probe senses a corresponding input which it receives from the strata.

  7. Integrating geology and perforating

    SciTech Connect

    Araujo, P.F. de; Souza Padilha, S.T.C. de

    1997-02-01

    Perforating is a very common well completion operation. Usually, it is considered to be as simple as making holes in casing. Actually, perforating is one of the most critical tasks for establishing a path from reservoir rock to borehole form which hydrocarbons can flow to surface. The objective of this article is to relate perforating technology with geological aspects and completion type to determine the best shooting equipment (gun type, charge and differential pressure) to perform the most efficient perforating job. Several subjects related to formation geology are taken into account for a shooting job, such as: compressive strength, reservoir pressure and thickness, lithology type, porosity and permeability, ratio between horizontal and vertical permeabilities, and fluid type. Gun geometry used in the oil industry incorporates several parameters, including shot density, hole entrance diameter, gun phase and jet penetration. API tests are done on perforating guns to define applicability and performance. A new geometrical parameter is defined as the relative angle of the jet, which is the angle between the jet tunnel and formation dip. GEOCAN is a methodology which relates geology to gun geometry and type to define the most efficient gun system for perforated completions. It uses the intelligent perforating technique with the SPAN (Schlumberger Perforating Analysis) program to confirm optimum gun choice.

  8. The Geology of Callisto

    NASA Technical Reports Server (NTRS)

    Schenk, Paul M.

    1995-01-01

    The geology of Callisto is not boring. Although cratered terrain dominates Callisto (a key end-member of the Jovian satellite system), a number of more interesting features are apparent. Cratered terrain is broken into irregular map-able bright and dark subunits that vary in albedo by a factor of 2, and several relatively smooth units are depleted of small craters. Some of these areas may have been volcanically resurfaced. Lineaments, including parallel and radial sets, may be evidence for early global tectonism. Frost deposition occurs in cold traps, and impact scars have formed from tidally disrupted comets. Geologic evidence suggests that Callisto does have a chemically differentiated crust. Central pit and central dome craters and palimpsests are common. The preferred interpretation is that a relatively ice-rich material, at depths of 5 km or more, has been mobilized during impact and exposed as domes or palimpsests. The close similarity in crater morphologies and dimensions indicates that the outermost 10 km or so of Callisto may be as differentiated as on Ganymede. The geology of cratered terrain on Callisto is simpler than that of cratered terrain on Ganymede, however. Orbital evolution and tidal heating may provide the answer to the riddle of why Callisto and Ganymede are so different (Malhotra, 1991). We should expect a few surprises and begins to answer some fundamental questions when Callisto is observed by Galileo in late 1996.

  9. Geologic Setting of Mosul Dam and Its Engineering Implications

    DTIC Science & Technology

    2007-09-01

    thought that an increase in vol- ume, produced during alteration of interbedded anhydrite to gypsum, generated sufficient pressure to fracture the...construction.. ..................................................................23 Figure 8. Geologic sections with water- pressure test values and...contains fragments or clasts of limestone, dolomite , or larger pieces of insoluble rocks of collapsed material. The upper portion of the accumulation

  10. Tsunami geology in paleoseismology

    USGS Publications Warehouse

    Yuichi Nishimura,; Jaffe, Bruce E.

    2015-01-01

    The 2004 Indian Ocean and 2011 Tohoku-oki disasters dramatically demonstrated the destructiveness and deadliness of tsunamis. For the assessment of future risk posed by tsunamis it is necessary to understand past tsunami events. Recent work on tsunami deposits has provided new information on paleotsunami events, including their recurrence interval and the size of the tsunamis (e.g. [187–189]). Tsunamis are observed not only on the margin of oceans but also in lakes. The majority of tsunamis are generated by earthquakes, but other events that displace water such as landslides and volcanic eruptions can also generate tsunamis. These non-earthquake tsunamis occur less frequently than earthquake tsunamis; it is, therefore, very important to find and study geologic evidence for past eruption and submarine landslide triggered tsunami events, as their rare occurrence may lead to risks being underestimated. Geologic investigations of tsunamis have historically relied on earthquake geology. Geophysicists estimate the parameters of vertical coseismic displacement that tsunami modelers use as a tsunami's initial condition. The modelers then let the simulated tsunami run ashore. This approach suffers from the relationship between the earthquake and seafloor displacement, the pertinent parameter in tsunami generation, being equivocal. In recent years, geologic investigations of tsunamis have added sedimentology and micropaleontology, which focus on identifying and interpreting depositional and erosional features of tsunamis. For example, coastal sediment may contain deposits that provide important information on past tsunami events [190, 191]. In some cases, a tsunami is recorded by a single sand layer. Elsewhere, tsunami deposits can consist of complex layers of mud, sand, and boulders, containing abundant stratigraphic evidence for sediment reworking and redeposition. These onshore sediments are geologic evidence for tsunamis and are called ‘tsunami deposits’ (Figs. 26

  11. The encyclopedia of applied geology

    SciTech Connect

    Finkl, C.W.

    1984-01-01

    This compendium of engineering geology data includes contributions by experts from many countries. Topics center around the field of engineering geology, with special focus on landscapes, earth materials, and the ''management'' of geological processes. How to use geology to serve man is given particular attention. More than 80 entries deal with hydrology, rock structure monitoring, soil mechanics, and engineering geology. Facts are provided on earth science information and sources, electrokinetics, forensic geology, geogryology, nuclear plant siting, photogrammetry, tunnels and tunneling, urban geomorphology, and well data systems. This guide explains the geology of alluvial plains, arid lands, beaches and coasts, delataic plains, cold regions, glacial landscapes, and urban environments. Detailed analyses are given of the geotechnical properties of caliche, clay, duricrust, soil, laterite, marine sediments, and rocks.

  12. 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)

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

    2011-12-01

    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 μm in diameter. Secondary fluid inclusions are <1 μm 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

  13. Geologic Mapping of Vesta

    NASA Technical Reports Server (NTRS)

    Yingst, R. A.; Mest, S. C.; Berman, D. C.; Garry, W. B.; Williams, D. A.; Buczkowski, D.; Jaumann, R.; Pieters, C. M.; De Sanctis, M. C.; Frigeri, A.; Le Corre, L.; Preusker, F.; Raymond, C. A.; Reddy, V.; Russell, C. T.; Roatsch, T.; Schenk, P. M.

    2014-01-01

    We report on a preliminary global geologic map of Vesta, based on data from the Dawn spacecraft's High- Altitude Mapping Orbit (HAMO) and informed by Low-Altitude Mapping Orbit (LAMO) data. This map is part of an iterative mapping effort; the geologic map has been refined with each improvement in resolution. Vesta has a heavily-cratered surface, with large craters evident in numerous locations. The south pole is dominated by an impact structure identified before Dawn's arrival. Two large impact structures have been resolved: the younger, larger Rheasilvia structure, and the older, more degraded Veneneia structure. The surface is also characterized by a system of deep, globe-girdling equatorial troughs and ridges, as well as an older system of troughs and ridges to the north. Troughs and ridges are also evident cutting across, and spiraling arcuately from, the Rheasilvia central mound. However, no volcanic features have been unequivocally identified. Vesta can be divided very broadly into three terrains: heavily-cratered terrain; ridge-and-trough terrain (equatorial and northern); and terrain associated with the Rheasilvia crater. Localized features include bright and dark material and ejecta (some defined specifically by color); lobate deposits; and mass-wasting materials. No obvious volcanic features are evident. Stratigraphy of Vesta's geologic units suggests a history in which formation of a primary crust was followed by the formation of impact craters, including Veneneia and the associated Saturnalia Fossae unit. Formation of Rheasilvia followed, along with associated structural deformation that shaped the Divalia Fossae ridge-and-trough unit at the equator. Subsequent impacts and mass wasting events subdued impact craters, rims and portions of ridge-and-trough sets, and formed slumps and landslides, especially within crater floors and along crater rims and scarps. Subsequent to the formation of Rheasilvia, discontinuous low-albedo deposits formed or were

  14. Okinawa, Japan: Geologic Battleground

    NASA Astrophysics Data System (ADS)

    Waymack, S. W.; Carrington, M. P.; Harpp, K. S.

    2005-12-01

    One of our main goals as instructors, particularly in introductory courses, is to impart students with an appreciation of how geology has influenced the course of human events. Despite the apparent accessibility of such topics, communicating this in a lively, relevant, and effective way often proves difficult. We use a series of historical events, the Pacific island hopping campaign of WWII, to engage students in an active, guided inquiry exercise to explore how terrain and the underlying geology of an area can shape historical events. Teams of students are assigned the role of planning either the defense or occupation of Okinawa Island, in the Ryukyu arc, in a theoretical version of the 1945 conflict. Students are given a package of information, including geologic and topographic maps, a list of military resources available to them at the time, and some historical background. Students also have access to "reconnaissance" images, 360o digital panoramas of the landscape of Okinawa, keyed to their maps. Each team has a week to plan their strategies and carry out additional research, which they subsequently bring to the table in the form of a written battle plan. With an instructor as arbiter, teams alternate drawing their maneuvers on a map of the island, to which the other team then responds. This continues one move at a time, until the instructor declares a victor. Throughout the exercise, the instructor guides students through analysis of each strategic decision in light of the island's structure and topography, with an emphasis on the appropriate interpretation of the maps. Students soon realize that an understanding of the island's terrain literally meant the difference between life and death for civilians and military participants alike in 1945. The karst landscape of Okinawa posed unique obstacles to both the Japanese and the American forces, including difficult landing sites, networks of natural caves, and sequences of hills aligned perpendicular to the

  15. Geologic mapping of Vesta

    NASA Astrophysics Data System (ADS)

    Yingst, R. A.; Mest, S. C.; Berman, D. C.; Garry, W. B.; Williams, D. A.; Buczkowski, D.; Jaumann, R.; Pieters, C. M.; De Sanctis, M. C.; Frigeri, A.; Le Corre, L.; Preusker, F.; Raymond, C. A.; Reddy, V.; Russell, C. T.; Roatsch, T.; Schenk, P. M.

    2014-11-01

    We report on a preliminary global geologic map of Vesta, based on data from the Dawn spacecraft's High-Altitude Mapping Orbit (HAMO) and informed by Low-Altitude Mapping Orbit (LAMO) data. This map is part of an iterative mapping effort; the geologic map has been refined with each improvement in resolution. Vesta has a heavily-cratered surface, with large craters evident in numerous locations. The south pole is dominated by an impact structure identified before Dawn's arrival. Two large impact structures have been resolved: the younger, larger Rheasilvia structure, and the older, more degraded Veneneia structure. The surface is also characterized by a system of deep, globe-girdling equatorial troughs and ridges, as well as an older system of troughs and ridges to the north. Troughs and ridges are also evident cutting across, and spiraling arcuately from, the Rheasilvia central mound. However, no volcanic features have been unequivocally identified. Vesta can be divided very broadly into three terrains: heavily-cratered terrain; ridge-and-trough terrain (equatorial and northern); and terrain associated with the Rheasilvia crater. Localized features include bright and dark material and ejecta (some defined specifically by color); lobate deposits; and mass-wasting materials. No obvious volcanic features are evident. Stratigraphy of Vesta's geologic units suggests a history in which formation of a primary crust was followed by the formation of impact craters, including Veneneia and the associated Saturnalia Fossae unit. Formation of Rheasilvia followed, along with associated structural deformation that shaped the Divalia Fossae ridge-and-trough unit at the equator. Subsequent impacts and mass wasting events subdued impact craters, rims and portions of ridge-and-trough sets, and formed slumps and landslides, especially within crater floors and along crater rims and scarps. Subsequent to the formation of Rheasilvia, discontinuous low-albedo deposits formed or were

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

    USGS Publications Warehouse

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

    2013-01-01

    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

  17. Sulfur and oxygen isotope study of the Vermont copper belt: evidence of seawater hydrothermal alteration and sulfate reduction in a high-grade metamorphic terrane

    SciTech Connect

    Shanks, W.C. III; Woodruff, L.G.; Slack, J.F.

    1985-01-01

    Massive sulfide deposits of the Orange County copper district, in east-central Vermont, consist of stratiform lenses of pyrrhotite, chalcopyrite, and minor sphalerite within amphibolite-facies rocks of Early Devonian (.) age. The deposits occur at several different stratigraphic levels. The two largest, Elizabeth and Ely, are in quartz-mica schists of the Gile Mountain Formation; the Pike Hill deposit occurs in calcareous quartz-mica schist of the underlying Waits River Formation. Two small deposits (Orange and Gove) are within the Standing Pond Volcanics, a thin tholeiitic amphibolite near the Gile Mountain-Waits River contact. The Elizabeth deposit in particularly distinctive, and contains a suite of unusual wall rocks rich in quartz, carbonate, muscovite, amphibole, phlogopite, tourmaline, spessartine, and sodic plagioclase. Sulfur isotope values at Elizabeth and Ely of 5.1 to 9.1 per thousands contrast with values for Gove (1.9 to 4.2) and Pike Hill (1.5 to 4.6). Disseminated sulfides in amphibolites of the Standing Pond Volcanics have sulfur isotope values in the range -0.1 to 1.7 per thousands, typical of MORB. These data require sulfur contributions to massive sulfide deposits both from basalt and from contemporaneous seawater sulfate sources. Whole-rock (carbonate free) oxygen isotope analyses of host lithologies range from 7.9 per thousands (Standing Pond Volcanics) to 19.9 per thousands (Waits River Formation). Detailed sampling of Elizabeth wall rocks (including those high in B, Na, Mg, Al, Si, Mn) yields a narrow range of oxygen isotope values (11.1 to 14.1); heavier values correlate with higher silica contents. Isotopically light wallrock lithologies are probably due to premetamorphic seawater hydrothermal alteration.

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

    NASA Astrophysics Data System (ADS)

    Baker, Victor R.

    2014-05-01

    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.

  19. Geology of northeastern Montana

    USGS Publications Warehouse

    Collier, Arthur J.

    1919-01-01

    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.

  20. Geologic Mapping of Mars

    NASA Astrophysics Data System (ADS)

    Price, Katherine H.

    1998-05-01

    Planetary geologic mapping involves integrating a terrestrial-based understanding of surface and subsurface processes and mapping principles to investigate scientific questions. Mars mappers must keep in mind that physical processes, such as wind and flowing water on Mars, are or were different from terrestrial processes because the planetary atmospheres have changed differently over time. Geologic mapping of Mars has traditionally been done by hand using overlays on photomosaics of Viking Orbiter and Mariner images. Photoclinometry and shadow measurements have been used to determine elevations, and the distribution and size of craters have been used to determine the relative ages of surfaces- more densely cratered surfaces are older. Some mappers are now using computer software (ranging from Photoshop to ArcInfo) to facilitate mapping, though their applications must be carefully executed so that registration of the images remains true. Images and some mapping results are now available on the internet, and new data from recent missions to Mars (Pathfinder and Surveyor) will offer clarifying information to mapping efforts. This paper consists chiefly of pictures and diagrams.

  1. Petroleum geology of Kuwait

    SciTech Connect

    Youash, Y.

    1988-02-01

    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.

  2. Experimental and geological approaches to elucidate chemical change in sporopollenin over geological time

    NASA Astrophysics Data System (ADS)

    Fraser, Wesley; Lomax, Barry; Jardine, Phillip

    2016-04-01

    Sporopollenin is the primary biopolymer comprising the walls of sporomorphs (pollen and spores), both in extant material and found within the fossil record. Maturation processes associated with sedimentation and burial over geological timescales have long been considered to dramatically alter the chemical nature of organic material, most notably via oxidation. Here we present experimental data derived from simulated maturation, analyses of Carboniferous fossil material, and modern-day material. Our data demonstrate the core structure of sporopollenin undergoes only minor chemical adjustments at lower grades of maturation, with the over-riding chemical signature remaining identifiable as that of sporopollenin, showing strong resemblance to modern material. This modern signature can, in specific cases be preserved in the geological record, demonstrated by the near-pristine chemical composition of megaspores preserved in cave deposits of Pennsylvanian age (Carboniferous, c. 310 Ma). Conversely, the labile component associated with sporopollenin is found to readily defunctionalise and repolymerise to generate a new polyalkyl macromolecule in situ. The labile component is shown to be held in position via ester linkages; a common chemical feature observed in extant sporopollenin. This combined experimental and geological investigation provides insights into i) the preservation of chemical signatures within the fossil record, ii) considerations for sample preparation when undertaking chemical analysis of fossil sporomorphs, and iii) the long-term evolutionary stasis of sporopollenin, spanning geological time.

  3. Structural Geology and Map Interpretation

    NASA Astrophysics Data System (ADS)

    Helper, Mark A.

    1998-06-01

    Geological maps lay flat the three-dimensional architecture of a region's rock record. In doing so, they reveal and document geometrical relationships and geological histories that would otherwise be difficult, if not impossible, to visualize. They are a primary data source for a wide range of practical applications, from civil engineering, mining, and energy resource exploration to urban planning and geologic hazard mitigation, and are literally the "ground truth" for understanding environments and processes of the Earth's past. Their utility resides not only in a plan-view portrayal of surface geology, but in the geometrical information they contain that allows projection of surface geology to the subsurface, or into regions where surface control is lacking. Understanding this predictive capacity and being able to read and truly appreciate a geological map's three-dimensional character are among the most unique and important skills a geologist masters. These same skills are unfortunately among the most difficult for students to learn.

  4. Geologic map of Io

    USGS Publications Warehouse

    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

    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

  5. Geologic report for the Beaufort Sea planning area, Alaska: regional geology, petroleum geology, environmental geology. Final report

    SciTech Connect

    Craig, J.D.; Sherwood, K.W.; Johnson, P.P.

    1985-12-01

    The 192-page report provides a summary of the geologic framework, hydrocarbon potential, and physical environment of the offshore area tentatively scheduled for Federal OCS (Outer Continental Shelf) Oil and Gas Lease Sale 97. The geologic interpretation is based on high-quality, gridded seismic reflection data and publicly available exploration wells. Seven regional seismic lines, released by Western Geophysical Company for this report, illustrate the geology of the petroleum provinces within the planning area. Hydrocarbon play concepts for large, untested areas of the continental margin off northern Alaska are developed from a detailed analysis of the structural and stratigraphic evolution. Environmental geology is described along with implications for future offshore petroleum activities.

  6. Geologic mapping of Europa

    USGS Publications Warehouse

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

    2000-01-01

    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

  7. Geology orbiter comparison study

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  8. Geology of Europa

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Chyba, C.; Head, J. W.; McCord, T.; McKinnon, W. B.; Pappalardo, R. T.

    2004-01-01

    Europa is a rocky object of radius 1565 km (slightly smaller than Earth s moon) and has an outer shell of water composition estimated to be of order 100 km thick, the surface of which is frozen. The total volume of water is about 3 x 10(exp 9) cubic kilometers, or twice the amount of water on Earth. Moreover, like its neighbor Io, Europa experiences internal heating generated from tidal flexing during its eccentric orbit around Jupiter. This raises the possibility that some of the water beneath the icy crust is liquid. The proportion of rock to ice, the generation of internal heat, and the possibility of liquid water make Europa unique in the Solar System. In this chapter, we outline the sources of data available for Europa (with a focus on the Galileo mission), review previous and on-going research on its surface geology, discuss the astrobiological potential of Europa, and consider plans for future exploration.

  9. Geology of National Parks

    USGS Publications Warehouse

    Stoffer, Philip W.

    2008-01-01

    This is a set of two sheets of 3D images showing geologic features of many National Parks. Red-and-cyan viewing glasses are need to see the three-dimensional effect. A search on the World Wide Web will yield many sites about anaglyphs and where to get 3D glasses. Red-blue glasses will do but red-cyan glasses are a little better. This publication features a photo quiz game: Name that park! where you can explore, interpret, and identify selected park landscapes. Can you identify landscape features in the images? Can you explain processes that may have helped form the landscape features? You can get the answers online.

  10. Geological consequences of superplumes

    SciTech Connect

    Larson, R.L. )

    1991-10-01

    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.

  11. Geologic Framework Model (GFM2000)

    SciTech Connect

    T. Vogt

    2004-08-26

    The purpose of this report is to document the geologic framework model, version GFM2000 with regard to input data, modeling methods, assumptions, uncertainties, limitations, and validation of the model results, and the differences between GFM2000 and previous versions. The version number of this model reflects the year during which the model was constructed. This model supersedes the previous model version, documented in Geologic Framework Model (GFM 3.1) (CRWMS M&O 2000 [DIRS 138860]). The geologic framework model represents a three-dimensional interpretation of the geology surrounding the location of the monitored geologic repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain. The geologic framework model encompasses and is limited to an area of 65 square miles (168 square kilometers) and a volume of 185 cubic miles (771 cubic kilometers). The boundaries of the geologic framework model (shown in Figure 1-1) were chosen to encompass the exploratory boreholes and to provide a geologic framework over the area of interest for hydrologic flow and radionuclide transport modeling through the unsaturated zone (UZ). The upper surface of the model is made up of the surface topography and the depth of the model is constrained by the inferred depth of the Tertiary-Paleozoic unconformity. The geologic framework model was constructed from geologic map and borehole data. Additional information from measured stratigraphic sections, gravity profiles, and seismic profiles was also considered. The intended use of the geologic framework model is to provide a geologic framework over the area of interest consistent with the level of detailed needed for hydrologic flow and radionuclide transport modeling through the UZ and for repository design. The model is limited by the availability of data and relative amount of geologic complexity found in an area. The geologic framework model is inherently limited by scale and content. The grid spacing used in the

  12. Geologic processes influence the effects of mining on aquatic ecosystems

    USGS Publications Warehouse

    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

    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.

  13. Geologic processes influence the effects of mining on aquatic ecosystems.

    PubMed

    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

    2012-04-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Klump, J. F.; Robertson, J.

    2015-12-01

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

  15. Thermal maturity patterns (conodont color alteration index and vitrinite reflectance) in Upper Ordovician and Devonian rocks of the Appalachian basin: a major revision of USGS Map I-917-E using new subsurface collections: Chapter F.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Repetski, John E.; Ryder, Robert T.; Weary, David J.; Harris, Anita G.; Trippi, Michael H.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The conodont color alteration index (CAI) introduced by Epstein and others (1977) and Harris and others (1978) is an important criterion for estimating the thermal maturity of Ordovician to Mississippian rocks in the Appalachian basin. Consequently, the CAI isograd maps of Harris and others (1978) are commonly used by geologists to characterize the thermal and burial history of the Appalachian basin and to better understand the origin and distribution of oil and gas resources in the basin. The main objectives of this report are to present revised CAI isograd maps for Ordovician and Devonian rocks in the Appalachian basin and to interpret the geologic and petroleum resource implications of these maps. The CAI isograd maps presented herein complement, and in some areas replace, the CAI-based isograd maps of Harris and others (1978) for the Appalachian basin. The CAI data presented in this report were derived almost entirely from subsurface samples, whereas the CAI data used by Harris and others (1978) were derived almost entirely from outcrop samples. Because of the different sampling methods, there is little geographic overlap of the two data sets. The new data set is mostly from the Allegheny Plateau structural province and most of the data set of Harris and others (1978) is from the Valley and Ridge structural province, east of the Allegheny structural front (fig. 1). Vitrinite reflectance, based on dispersed vitrinite in Devonian black shale, is another important parameter for estimating the thermal maturity in pre-Pennsylvanian-age rocks of the Appalachian basin (Streib, 1981; Cole and others, 1987; Gerlach and Cercone, 1993; Rimmer and others, 1993; Curtis and Faure, 1997). This chapter also presents a revised percent vitrinite reflectance (%R0) isograd map based on dispersed vitrinite recovered from selected Devonian black shales. The Devonian black shales used for the vitrinite studies reported herein also were analyzed by RockEval pyrolysis and total organic

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

    USGS Publications Warehouse

    Parker, John Mason

    1963-01-01

    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

  17. Divisions of geologic time (Bookmark)

    USGS Publications Warehouse

    ,

    2012-05-03

    DescriptionThis bookmark, designed for use with U.S. Geological Survey activities at the second 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.

  18. Creationism, Uniformitarianism, Geology and Science.

    ERIC Educational Resources Information Center

    Shea, James H.

    1983-01-01

    Points out that the most basic of creationist attacks of geology, their claim that uniformitarianism is an unreliable basis for interpreting the past, fail because the uniformitarianism they describe is no longer a part of geology. Indicates that modern uniformitarianism is merely the philosophical principle of simplicity. (Author/JN)

  19. The Geophysical Revolution in Geology.

    ERIC Educational Resources Information Center

    Smith, Peter J.

    1980-01-01

    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…

  20. Geologic mapping of Argyre Planitia

    NASA Technical Reports Server (NTRS)

    Gorsline, Donn S.; Parker, Timothy J.

    1995-01-01

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

  1. Photomicrography in the Geological Sciences.

    ERIC Educational Resources Information Center

    Davidson, Michael W.

    1991-01-01

    Describes the conversion of a standard biological brightfield microscope for examination of thin sections and characterize, in detail, the use of both black and white and color photomicrography in the geological sciences. Several illustrative examples on the use of transmitted and reflected polarized-light microscopy to solve geological problems…

  2. Geology of the Wood and East Calhoun mines, Central City District, Gilpin County, Colorado

    USGS Publications Warehouse

    Drake, Avery Ala

    1955-01-01

    The Wood-East Calhoun mine area is underlain by complexly folded Precambrian gneiss and pegmatite. The major fold in the area is an anticline that trends about N. 60° E. The Precambrian rocks are intruded by bostonite porphyry dikes of Tertiary age. All the rocks are cut by east- to northeast - trending faults that have been filled by precious metal-sulfide veins which have been worked chiefly for gold. The Wood vein occurs in an east-trending fault; the Calhoun vein occurs in a northeast-trending fault. Much of the uranium production of the Central City district has come from the Wood vein on Quartz Hill. The veins consist chiefly of quartz; pyrite is the chief metallic mineral and chalcopyrite is next in abundance. Sphalerite, galena, tetrahedrite-tennantite, and pitchblende are locally present. Deposition began with alteration-stage quartz and pyrite followed in order by pitchblend, light-yellow pyrite, massive quartz, yellow pyrite, shalerite, comb quartz, chalcopyrite, tetrahedrite-tennantite, galena, chalcopyrite, pyrite, and gray to light-brown fine-grained quartz. The veins of the Central City district are zoned, with quartz-pyrite veins near the center and galena-sphalerite veins on the periphery. The known pitchblende bodies are in the transition between these, but paragenetically, the pitchblende is earlier than all other metallic minerals. A trace element study of the ore indicates an association of zirconium and molybdenum with uranium, of bismuth, antimony, and arsenic with copper, and of cadmium with zinc. The pitchblende and other ore minerals are concentrated in ore shoots. The shoots are in open spaces controlled by the competency of the wall rocks, the presence of a prevailing direction of weakness in the rocks, and changes in strike and dip of the vein. The pitchblende is thought to be a local constituent of the quartz-pyrite ores and to owe its origin to residual solutions from the quartz bostonite magma.

  3. The Geologic Nitrogen Cycle

    NASA Astrophysics Data System (ADS)

    Johnson, B. W.; Goldblatt, C.

    2013-12-01

    N2 is the dominant gas in Earth's atmosphere, and has been so through the majority of the planet's history. Originally thought to only be cycled in significant amounts through the biosphere, it is becoming increasingly clear that a large degree of geologic cycling can occur as well. N is present in crustal rocks at 10s to 100s of ppm and in the mantle at 1s to perhaps 10s of ppm. In light of new data, we present an Earth-system perspective of the modern N cycle, an updated N budget for the silicate Earth, and venture to explain the evolution of the N cycle over time. In an fashion similar to C, N has a fast, biologically mediated cycle and a slower cycle driven by plate tectonics. Bacteria fix N2 from the atmosphere into bioavailable forms. N is then cycled through the food chain, either by direct consumption of N-fixing bacteria, as NH4+ (the primary waste form), or NO3- (the most common inorganic species in the modern ocean). Some organic material settles as sediment on the ocean floor. In anoxic sediments, NH4+ dominates; due to similar ionic radii, it can readily substitute for K+ in mineral lattices, both in sedimentary rocks and in oceanic lithosphere. Once it enters a subduction zone, N may either be volatilized and returned to the atmosphere at arc volcanoes as N2 or N2O, sequestered into intrusive igneous rocks (as NH4+?), or subducted deep into the mantle, likely as NH4+. Mounting evidence indicates that a significant amount of N may be sequestered into the solid Earth, where it may remain for long periods (100s m.y.) before being returned to the atmosphere/biosphere by volcanism or weathering. The magnitude fluxes into the solid Earth and size of geologic N reservoirs are poorly constrained. The size of the N reservoirs contained in the solid Earth directly affects the evolution of Earth's atmosphere. It is possible that N now sequestered in the solid Earth was once in the atmosphere, which would have resulted in a higher atmospheric pressure, and

  4. Surficial geological tools in fluvial geomorphology

    USGS Publications Warehouse

    Jacobson, Robert B.; O'connor, James; Oguchi, Takashi

    2016-01-01

    Environmental scientists are increasingly asked how rivers and streams have been altered by past environmental stresses, whether rivers are subject to physical or chemical hazards, how they can be restored and how they will respond to future environmental changes. These questions present substantive challenges to the discipline of fluvial geomorphology as they require a long-term understanding of river-system dynamics. Complex and non-linear responses of rivers to environmental stresses indicate that synoptic or short-term historical views of rivers will often give an incomplete understanding. Fluvial geomorphologists can address questions involving complex river behaviours by drawing from a tool box that includes the principles and methods of geology applied to the surficial geological record. A central concept in Earth Sciences holds that ‘the present is the key to the past’ (Hutton 1788, cited in Chorley et al. 1964), that is, understanding of current processes permits the interpretation of past deposits. Similarly, an understanding of the past can be key to predicting the future. A river’s depositional history can be indicative of trends or episodic behaviours that can be attributed to particular environmental stresses or forcings. Its history may indicate the role of low-frequency events such as floods or landslides in structuring a river and its floodplain or a river’s depositional history can provide an understanding of its natural characteristics to serve as a reference condition for assessments and restoration. However, the surficial geological record contained in river deposits is incomplete and biased and it presents numerous challenges of interpretation. The stratigraphic record in general has been characterized as ‘ … a lot of holes tied together with sediment’ (Ager 1993). Yet this record is critical in the development of integrated understanding of fluvial geomorphology because it provides information that is not available from other

  5. 78 FR 57877 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ....S. Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical Data Preservation Program (NGGDPP) Advisory Committee AGENCY: U.S. Geological Survey....-5 p.m. Mountain Standard Time. The Advisory Committee, comprising representatives from...

  6. The Geology of Titan

    NASA Astrophysics Data System (ADS)

    Jaumann, Ralf

    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

  7. The geology of Io

    NASA Astrophysics Data System (ADS)

    Schaber, G. G.

    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.

  8. Geologic Sequestration Software Suite

    SciTech Connect

    Black, Gary; Bonneville, PNNL Alain; Sivaramakrishnan, PNNL Chandrika; Purohit, PNNL Sumit; White, PNNL Signe; Lansing, PNNL Carina; Gosink, PNNL Luke; Guillen, PNNL Zoe; Moeglein, PNNL William; Gorton, PNNL Ian; PNNL,

    2013-11-04

    GS3 is the bundling of the Geological Sequestration Software Suite domain tools with the Velo wiki user interface, rich client interface, and data store. Velo is an application domain independent collaborative user environment for modeling and simulation. Velo has a web browser based wiki interface integrated with a sophisticated content management system supporting data and knowledge management required for large-scale scientific modeling projects. GS3 adds tools and capability specifically in the area of modeling subsurface reservoirs for the purpose of carbon sequestration. Velo is a core software framework to create scientific domain user environments. Velo is not tied to a specific domain although it provides novel capability needed by many application areas. A well-defined Velo integration layer allows custom applications such as GS3 to leverage the core Velo components to reduce development cost/time and ultimately provide a more capable software product. Compared with previous efforts like ECCE and SALSSA, Velo is a major advancement being a web browser based interface, having a more comprehensive data management architecture, and having intrinsic support for collaboration through the wiki. GS3 adds specific domain tools for looking at site data, developing conceptual and numerical models, building simulation input files, launching and monitoring the progress of those simulations and being able to look at and interpret simulation output.

  9. Viruses as new agents of organomineralization in the geological record.

    PubMed

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

    2014-07-03

    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.

  10. 30 CFR 780.22 - Geologic information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Geologic information shall include, at a minimum the following: (1) A description of the geology of the... adversely impacted by mining. The description shall include the areal and structural geology of the...

  11. 30 CFR 780.22 - Geologic information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Geologic information shall include, at a minimum the following: (1) A description of the geology of the... adversely impacted by mining. The description shall include the areal and structural geology of the...

  12. 30 CFR 780.22 - Geologic information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Geologic information shall include, at a minimum the following: (1) A description of the geology of the... adversely impacted by mining. The description shall include the areal and structural geology of the...

  13. 30 CFR 780.22 - Geologic information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Geologic information shall include, at a minimum the following: (1) A description of the geology of the... adversely impacted by mining. The description shall include the areal and structural geology of the...

  14. Geology of the Alaska-Juneau lode system, Alaska

    USGS Publications Warehouse

    Twenhofel, William Stephens

    1952-01-01

    inches to 3 feet wide and extending along their strike and dip for several tens to hundreds of feet. In addition to quartz, the only other vein gangue mineral is ankerite. It occurs in small amounts along the borders of the quartz veins. Metallic vein minerals, in addition to native gold, are, in order of decreasing abundance, pyrrhotite, galena, sphalerite, and arsenopyrite. In the aggregate the metallic minerals comprise only 1 to 2 percent of the total amount of vein material. The wall rock, particularly the meta-gabbro, was profoundly altered by the vein-forming processes. The principal effects on the meta-gabbro were the addition of large amounts of soda, potash, titanium, carbon dioxide, and phosphorous, and the removal of considerable quantities of iron, magnesia, lime, and combined water. Silica also may have been decreased. The mineralogical changes involved in the alteration were the development of biotite and ankerite at the expense of original hornblende and feldspar, resulting in a brown-colored biotite- and ankerite-rich rock. The slates are relatively unaffected by the vein-forming processes. Because of their small size, relatively low grade, and discontinuity, no attempt has been made to mine any individual vein. The prevailing practice has been to mine large blocks of ground by a system of modified block-caving, followed by hand sorting to remove the barren country rock from the gold-bearing quartz prior to milling.

  15. The Geology of Gaspra

    USGS Publications Warehouse

    Carr, M.H.; Kirk, R.L.; McEwen, A.; Veverka, J.; Thomas, P.; Head, J.W.; Murchie, S.

    1994-01-01

    The surface of Gaspra can be divided into several facets separated by ridges. Superimposed on the facets and ridges are two populations of craters. Type 1 craters are crisply defined and constitute a production function of impact origin. Type 2 craters are mostly irregular shallow depressions and probably of various origins. Some of the type 2 craters may have formed by impact and be remnants of a crater population that predates the type 1 population. The number of type 1 craters suggests that they started to accumulate 2 ?? 107 to 3 ?? 108 years ago. The freshest craters have a depth/diameter ratio of 1:7, as compared with 1:5 typically observed on other bodies. The craters appear to have become shallower with age at a rate of 10-6 to 10-7 m/year. The shallow depth of newly formed craters and the progressive degradation with age are ascribed to downslope movement of poorly coherent surface materials, the movement being aided by seismic shaking as a result of impact. The surface shows subtle color differences. The most prominent differences are observed around craters on ridges, where the surface has a stronger 1-??m absorption than elsewhere. The contrast is not observed around craters on the facets. The color differences are attributed to alteration of the materials brought to the surface. The unaltered material is estimated to be located at least 50 m below the surface on the facets. Only on the ridges is unaltered material at a shallow enough depth to be excavated by the observed craters. The rate of degradation of craters, the rounded form of the ridges, the depth of altered material on the facets, and the presence of old degraded craters all suggest that Gaspra is covered with a regolith a few tens to several tens of meters thick. ?? 1994 Academic Press. All rights reserved.

  16. Global Geologic Mapping of Io: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Williams, David A.; Keszthelyi, L. P.; Crown, D. A.; Geissler, P. E.; Schenk, P. M.; Yff, Jessica; Jaeger, W. L.; Rathbun, J. A.

    2008-01-01

    A new global geologic map of Jupiter's volcanic moon, Io is being prepared, with the focus being on completion of a draft map by July 2008. Here initial results of the mapping are reported: a preliminary distribution of material units in terms of areas and a visual representation. Additionally, the mapping hopes to address some of the problems in Io geology. Thus far it has been discovered that Io's surface is dominated by plains material, thought to consist of Io's silicate crust covered by pyroclastic deposits and lava flows of silicate and sulfur-bearing composition. Many plains areas contain flow fields that cannot be mapped separately due to a lack of resolution or modification by alteration processes. Discrete lava flows and flow fields are the next most abundant unit, with bright (sulfur?) flows in greater abundance than dark (silicate?) flows. The source of most of Io's heat flow, the paterae, are the least abundant unit in terms of areal extent.Upon completion of the draft map for peer review, it will be used to investigate several specific questions about the geological evolution of Io that previously could not be well addressed, including: comparison of the areas versus the heights of Ionian mountains to assess their stability and evolution; correlation and comparison of Galileo Near-Infrared Mapping Spectrometer and Photopolarimeter-Radiometer hot spot locations with the mapped location of dark versus bright lava flows and patera floors to assess any variations in the types of sources for Io's active volcanism; and the creation of a global inventory of the areal coverage of dark and bright laval flows to assess the relative importance of sulfur versus silicate volcanism in resurfacing Io, and to assess whether there are regional concentrations of either style of volcanism that may have implications on interior processes.

  17. Modelling glass alteration in an altered argillaceous environment

    NASA Astrophysics Data System (ADS)

    Bildstein, O.; Trotignon, L.; Pozo, C.; Jullien, M.

    2007-05-01

    The long term behaviour of materials such as glass, steel and clay has been investigated in the context of deep geological disposal of radioactive wastes. The interactions between vitrified wastes, canister corrosion products (CPs) and clay are studied using a modified version of the reaction-transport code Crunch, especially looking at pH changes and possible cementation at the interface with the clayey materials. These perturbations may indeed affect the lifetime of glass matrix in deep repositories, e.g., high pH enhances the rate of glass alteration. This work focuses on the argillite of Bure. The calculations were performed at 323 K with a glass alteration rate switching from a high initial rate to a residual rate according to the sorption capacity of CPs. The time at which this sorption capacity is saturated is crucial to the system in terms of wastes package lifetime. The results show that the glass alteration imposes a high pH value at the interface with CPs and clay: up to a value of 9.2, compared to 7.3 which is the initial pH value in the argillite. Experimental data show that the rate of glass alteration is much higher in such pH conditions. For a R7T7-type glass, the rate is about five times higher at pH 9 than at pH 7. This pH perturbation migrates through the clayey domain as a result of the migration of mobile elements such as boron and sodium, and despite the existence of strong pH buffers in the argillite. The cementation of porosity at the interface between glass and clay is predicted by the model due to the massive precipitation of iron corrosion products and glass alteration products. At this point of the evolution of the system, the pH starts to decrease and the alteration rate of the glass could be significantly reduced. This porosity clogging effect is difficult to confirm by experiments especially since existing data on short term experiments tend to show a pervasive precipitation of silica in the domain instead of a localized precipitation

  18. Mineral resources, geological structure, and landform surveys

    NASA Technical Reports Server (NTRS)

    Short, N. M.

    1974-01-01

    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.

  19. Geology, distribution, and classification of gold deposits in the western Qinling belt, central China

    USGS Publications Warehouse

    Mao, J.; Qiu, Y.; Goldfarb, R.J.; Zhang, Z.; Garwin, S.; Fengshou, R.

    2002-01-01

    Gold deposits of the western Qinling belt occur within the western part of the Qinling-Dabie-Sulu orogen, which is located between the Precambrian North China and Yangtze cratons and east of the Songpan-Ganzi basin. The early Paleozoic to early Mesozoic orogen can be divided into northern, central, and southern zones, separated by the Shangdan and Lixian-Shanyang thrust fault systems. The northern zone consists of an early Paleozoic arc accreted to the North China craton by ca. 450 Ma. The central zone, which contains numerous orogenic gold deposits, is dominated by clastic rocks formed in a late Paleozoic basin between the converging cratonic blocks. The southern zone is characterized by the easternmost exposure of Triassic sedimentary rocks of the Songpan-Ganzi basin. These Early to Late Triassic turbidities, in part calcareous, of the immense Songpan-Ganzi basin also border the western Qinling belt to the west. Carlinlike gold deposits are abundant (1) along a westward extension of the southern zone defined by a window of early Paleozoic clastic rocks extending into the basin, and (2) within the easternmost margin of the basinal rocks to the south of the extension, and in adjacent cover rocks of the Yangtze craton. Triassic and Early Jurassic synkinematic granitoids are widespread across the western Qinling belt, as well as in the Songpan-Ganzi basin. Orogenic lode gold deposits along brittle-ductile shear zones occur within greenschist-facies, highly deformed, Devonian and younger clastic rocks of the central zone. Mainly coarse-grained gold, along with pyrite, pyrrhotite, arsenopyrite, and minor base metal sulfides, occur in networks of quartz veinlets, brecciated wall rock, and are dissminated in altered wall rock. Isotopic dates suggest that the deposits formed during the Late Triassic to Middle Jurassic as the leading edge of the Yangtze craton was thrust beneath rocks of the western Qinling belt. Many gold-bearing placers are distributed along the river

  20. Planetary Geologic Mapping Handbook - 2009

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

    Geologic maps present, in an historical context, fundamental syntheses of interpretations of the materials, landforms, structures, and processes that characterize planetary surfaces and shallow subsurfaces (e.g., Varnes, 1974). Such maps also provide a contextual framework for summarizing and evaluating thematic research for a given region or body. In planetary exploration, for example, geologic maps are used for specialized investigations such as targeting regions of interest for data collection and for characterizing sites for landed missions. Whereas most modern terrestrial geologic maps are constructed from regional views provided by remote sensing data and supplemented in detail by field-based observations and measurements, planetary maps have been largely based on analyses of orbital photography. For planetary bodies in particular, geologic maps commonly represent a snapshot of a surface, because they are based on available information at a time when new data are still being acquired. Thus the field of planetary geologic mapping has been evolving rapidly to embrace the use of new data and modern technology and to accommodate the growing needs of planetary exploration. Planetary geologic maps have been published by the U.S. Geological Survey (USGS) since 1962 (Hackman, 1962). Over this time, numerous maps of several planetary bodies have been prepared at a variety of scales and projections using the best available image and topographic bases. Early geologic map bases commonly consisted of hand-mosaicked photographs or airbrushed shaded-relief views and geologic linework was manually drafted using mylar bases and ink drafting pens. Map publishing required a tedious process of scribing, color peel-coat preparation, typesetting, and photo-laboratory work. Beginning in the 1990s, inexpensive computing, display capability and user-friendly illustration software allowed maps to be drawn using digital tools rather than pen and ink, and mylar bases became obsolete

  1. Terrestrial and Lunar Geological Terminology

    NASA Technical Reports Server (NTRS)

    Schrader, Christian

    2009-01-01

    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.

  2. A primer in lunar geology

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    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.

  3. Perspectives in geology. Circular 525

    SciTech Connect

    Not Available

    1982-01-01

    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)

  4. Tethys geology and tectonics revisited

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1991-01-01

    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.

  5. Central American geologic map project

    SciTech Connect

    Dengo, G.

    1986-07-01

    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.

  6. Q&A: Geological historian

    NASA Astrophysics Data System (ADS)

    Witze, Alexandra

    2015-04-01

    The first geological map of a nation was made 200 years ago by British surveyor William Smith; the rediscovery of a first-edition copy in the archives of the Geological Society of London was announced last month (see go.nature.com/oogpht). As researchers gather for a conference to celebrate the anniversary of the 1815 chart of England and Wales, John Henry, chair of the society's history group, talks about the map and its pioneering creator.

  7. Bedrock geologic map of Vermont

    USGS Publications Warehouse

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

    2011-01-01

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

  8. Remote sensing aids geologic mapping

    NASA Technical Reports Server (NTRS)

    Knepper, D. H., Jr.; Marrs, R. W.

    1972-01-01

    Remote sensing techniques were applied to general geologic mapping along the Rio Grande rift zone in central Colorado. A geologic map of about 1,100 square miles was prepared utilizing (1) prior published and unpublished maps, (2) detailed and reconnaissance field maps made for this study, and (3) remote sensor data interpretations. The map is used for interpretation of the complex Cenozoic tectonic and geomorphic histories of the area.

  9. Osmotic generation of 'anomalous' fluid pressures in geological environments

    USGS Publications Warehouse

    Neuzii, C.E.

    2000-01-01

    Osmotic pressures are generated by differences in chemical potential of a solution across a membrane. But whether osmosis can have a significant effect on the pressure of fluids in geological environments has been controversial, because the membrane properties of geological media are poorly understood. 'Anomalous' pressures - large departures from hydrostatic pressure that are not explicable in terms of topographic or fluid-density effects are widely found in geological settings, and are commonly considered to result from processes that alter the pore or fluid volume, which in turn implies crustal changes happening at a rate too slow to observe directly. Yet if osmosis can explain some anomalies, there is no need to invoke such dynamic geological processes in those cases. Here I report results of a nine- year in situ measurement of fluid pressures and solute concentrations in shale that are consistent with the generation of large (up to 20 MPa) osmotic-pressure anomalies which could persist for tens of millions of years. Osmotic pressures of this magnitude and duration can explain many of the pressure anomalies observed in geological settings. The require, however, small shale porosity and large contrasts in the amount of dissolved solids in the pore waters - criteria that may help to distinguish between osmotic and crystal-dynamic origins of anomalous pressures.

  10. Geological myths and reality

    NASA Astrophysics Data System (ADS)

    Ostrihansky, Lubor

    2014-05-01

    Myths are the result of man's attempts to explain noteworthy features of his environment stemming from unfounded imagination. It is unbelievable that in 21st century the explanation of evident lithospheric plates movements and origin of forces causing this movement is still bound to myths, They are the myth about mantle convection, myth about Earth's expansion, myth about mantle heterogeneities causing the movement of plates and myth about mantle plumes. From 1971 to 1978 I performed extensive study (Ostřihanský 1980) about the terrestrial heat flow and radioactive heat production of batholiths in the Bohemian Massive (Czech Republic). The result, gained by extrapolation of the heat flow and heat production relationship, revealed the very low heat flow from the mantle 17.7mW m-2 close to the site of the Quarterly volcano active only 115,000 - 15,000 years ago and its last outbreak happened during Holocene that is less than 10,000 years ago. This volcano Komorní Hůrka (Kammerbühls) was known by J. W. Goethe investigation and the digging of 300 m long gallery in the first half of XIX century to reach the basaltic plug and to confirm the Stromboli type volcano. In this way the 19th century myth of neptunists that basalt was a sedimentary deposit was disproved in spite that famous poet and scientist J.W.Goethe inclined to neptunists. For me the result of very low heat flow and the vicinity of almost recent volcanoes in the Bohemian Massive meant that I refused the hypothesis of mantle convection and I focused my investigation to external forces of tides and solar heat, which evoke volcanic effects, earthquakes and the plate movement. To disclose reality it is necessary to present calculation of acting forces using correct mechanism of their action taking into account tectonic characteristics of geologic unites as the wrench tectonics and the tectonic of planets and satellites of the solar system, realizing an exceptional behavior of the Earth as quickly rotating

  11. Titan's global geologic processes

    NASA Astrophysics Data System (ADS)

    Malaska, Michael; Lopes, Rosaly M. C.; Schoenfeld, Ashley; Birch, Samuel; Hayes, Alexander; Williams, David A.; Solomonidou, Anezina; Janssen, Michael A.; Le Gall, Alice; Soderblom, Jason M.; Neish, Catherine; Turtle, Elizabeth P.; Cassini RADAR Team

    2016-10-01

    We have mapped the Cassini SAR imaged areas of Saturn's moon Titan in order to determine the geological properties that modify the surface [1]. We used the SAR dataset for mapping, but incorporated data from radiometry, VIMS, ISS, and SARTopo for terrain unit determination. This work extends our analyses of the mid-latitude/equatorial Afekan Crater region [2] and in the southern and northern polar regions [3]. We placed Titan terrains into six broad terrain classes: craters, mountain/hummocky, labyrinth, plains, dunes, and lakes. We also extended the fluvial mapping done by Burr et al. [4], and defined areas as potential cryovolcanic features [5]. We found that hummocky/mountainous and labyrinth areas are the oldest units on Titan, and that lakes and dunes are among the youngest. Plains units are the largest unit in terms of surface area, followed by the dunes unit. Radiometry data suggest that most of Titan's surface is covered in high-emissivity materials, consistent with organic materials, with only minor exposures of low-emissivity materials that are consistent with water ice, primarily in the mountain and hummocky areas and crater rims and ejecta [6, 7]. From examination of terrain orientation, we find that landscape evolution in the mid-latitude and equatorial regions is driven by aeolian processes, while polar landscapes are shaped by fluvial, lacrustine, and possibly dissolution or volatilization processes involving cycling organic materials [3, 8]. Although important in deciphering Titan's terrain evolution, impact processes play a very minor role in the modification of Titan's landscape [9]. We find no evidence for large-scale aqueous cryovolcanic deposits.References: [1] Lopes, R.M.C. et al. (2010) Icarus, 205, 540-558. [2] Malaska, M.J. et al. (2016) Icarus, 270, 130-161. [3] Birch et al., in revision. [4] Burr et al. (2013) GSA Bulletin 125, 299-321. [5] Lopes et al. JGR: Planets, 118, 1-20. [6] Janssen et al., (2009) Icarus, 200, 222-239. [7] Janssen

  12. Quaternary geologic map of Minnesota

    NASA Technical Reports Server (NTRS)

    Goebel, J. E.

    1977-01-01

    The Quaternary Geologic Map of Minnesota is a compilation based both on the unique characteristics of satellite imagery and on the results of previous field investigations, both published and unpublished. The use of satellite imagery has made possible the timely and economical construction of this map. LANDSAT imagery interpretation proved more useful than expected. Most of the geologic units could be identified by extrapolating from specific sites where the geology had been investigated into areas where little was known. The excellent geographic registry coupled with the multi-spectral record of these images served to identify places where the geologic materials responded to their ecological environment and where the ecology responded to the geologic materials. Units were well located on the map at the scale selected for the study. Contacts between till units could be placed with reasonable accuracy. The reference points that were used to project delineations between units (rivers, lakes, hills, roads and other features), which had not been accurately located on early maps, could be accurately located with the help of the imagery. The tonal and color contrasts, the patterns reflecting geologic change and the resolution of the images permitted focusing attention on features which could be represented at the final scale of the map without distraction by other interesting but site-specific details.

  13. Global Geologic Map of Europa

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

  14. Health benefits of geologic materials and geologic processes

    USGS Publications Warehouse

    Finkelman, R.B.

    2006-01-01

    The reemerging field of Medical Geology is concerned with the impacts of geologic materials and geologic processes on animal and human health. Most medical geology research has been focused on health problems caused by excess or deficiency of trace elements, exposure to ambient dust, and on other geologically related health problems or health problems for which geoscience tools, techniques, or databases could be applied. Little, if any, attention has been focused on the beneficial health effects of rocks, minerals, and geologic processes. These beneficial effects may have been recognized as long as two million years ago and include emotional, mental, and physical health benefits. Some of the earliest known medicines were derived from rocks and minerals. For thousands of years various clays have been used as an antidote for poisons. "Terra sigillata," still in use today, may have been the first patented medicine. Many trace elements, rocks, and minerals are used today in a wide variety of pharmaceuticals and health care products. There is also a segment of society that believes in the curative and preventative properties of crystals (talismans and amulets). Metals and trace elements are being used in some of today's most sophisticated medical applications. Other recent examples of beneficial effects of geologic materials and processes include epidemiological studies in Japan that have identified a wide range of health problems (such as muscle and joint pain, hemorrhoids, burns, gout, etc.) that may be treated by one or more of nine chemically distinct types of hot springs, and a study in China indicating that residential coal combustion may be mobilizing sufficient iodine to prevent iodine deficiency disease. ?? 2006 MDPI. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    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

  16. Geology Field Trips as Performance Evaluations

    ERIC Educational Resources Information Center

    Bentley, Callan

    2009-01-01

    One of the most important goals the author has for students in his introductory-level physical geology course is to give them the conceptual skills for solving geologic problems on their own. He wants students to leave his course as individuals who can use their knowledge of geologic processes and logic to figure out the extended geologic history…

  17. The U. S. Geological Survey Geologic Hazards Program

    USGS Publications Warehouse

    Peck, D.L.

    1982-01-01

    In 1879, Congress established the U.S Geological Survey for "the classification of the public lands and the examination of the geological structure, mineral resources, and products of the national domain." Throughout the past 103 years, the Survey has successfully fulfilled these responsibilities, but it has also been responsive to changing national needs. This responsiveness is well exemplified by the development of the agency's natural hazard programs. Our orignial mision has been expanded to include formal investigations of earthquakes, volcanic eruptions, ground failures, and flood hazards. 

  18. Geology of the Jabal Riah area, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Wells, J.D.

    1982-01-01

    silver are most abundant in calcium-rich rocks and veins; silver was not detected in igneous rocks. Altered wall-rock zones are mineralized as much as 10 m away from the veins. Away from the Jabal Mahanid vein-system, silver was detected in the jasper. Gold and silver were detected in minor brecciated and sheared structures and in metasedimentary rocks. Gold was detected in sericitized margins of the leucocratic quartz porphyry, in unaltered rhyolite, and in aplite dikes. The presence of unusual amounts of gold and silver over a wide area is indicated by the ancient gold mines along veins at or near the hornblende schist-serpentinite contact in the map area and to the south in the Hajrah-Hamdah area and by the widespread evidence of precious metals in igneous rocks and other vein structures. A domed-shaped area, approximately 30 km in diameter, is outlined by the hornblende schist-serpentinite contact and has leucocratic quartz prophyry in the middle. Additional study of this area might reveal economic concentrations of gold and silver.

  19. Geology of petroleum in Campos basin, Brazil

    SciTech Connect

    Meister, E.M.

    1984-04-01

    A schematic model of oil generation, migration, accumulation, and alteration is presented for the Campos basin, a sedimentary province covering an area of nearly 31,000 km/sup 2/ (12,000 mi/sup 2/) offshore southeastern Brazil, where an estimated 1 billion m/sup 3/ (6.3 billion bbl) of oil in place has been discovered since 1974. Source rocks for this oil belong to the Lower Cretaceous Lagoa Feia Formation; oil generation probably started in the Miocene. At that time, a series of local windows opened in the regional evaporite seal at the top of the Lagoa Feia Formation and focused the upward escape of hydrocarbons, mainly along halokinetic fault surfaces. Reservoirs of Albian, Late Cretaceous, and Tertiary age were charged and their porosities enhanced by natural fracturing, solution, and/or grain rearrangement. Original oil (postulated range of 30/sup 0/-35/sup 0/ API gravity) underwent differentiation by migration, reflected in relative enrichment of aromatics and of the light /sup 12/C stable carbon isotope. Alteration of oil by water occurs if one of the two fluids in contact is allochthonous; bacterial alteration is important in low-temperature regimes. Oil entrapment is helped by hydrodynamic conditions, with the intake area of the Paraiba do Sul river delta supposedly playing an important part. Lopatin-type plots gave the first clue for establishing this model, which takes into account a large number of facts about the basin, such as well and seismic information, clay diagenesis, water and petroleum geochemistry, pressure data, and their geologic field relationships.

  20. Shuttle Imaging Radar - Geologic applications

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    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.

  1. Sketch-based geologic modeling

    NASA Astrophysics Data System (ADS)

    Rood, M. P.; Jackson, M.; Hampson, G.; Brazil, E. V.; de Carvalho, F.; Coda, C.; Sousa, M. C.; Zhang, Z.; Geiger, S.

    2015-12-01

    Two-dimensional (2D) maps and cross-sections, and 3D conceptual models, are fundamental tools for understanding, communicating and modeling geology. Yet geologists lack dedicated and intuitive tools that allow rapid creation of such figures and models. Standard drawing packages produce only 2D figures that are not suitable for quantitative analysis. Geologic modeling packages can produce 3D models and are widely used in the groundwater and petroleum communities, but are often slow and non-intuitive to use, requiring the creation of a grid early in the modeling workflow and the use of geostatistical methods to populate the grid blocks with geologic information. We present an alternative approach to rapidly create figures and models using sketch-based interface and modelling (SBIM). We leverage methods widely adopted in other industries to prototype complex geometries and designs. The SBIM tool contains built-in geologic rules that constrain how sketched lines and surfaces interact. These rules are based on the logic of superposition and cross-cutting relationships that follow from rock-forming processes, including deposition, deformation, intrusion and modification by diagenesis or metamorphism. The approach allows rapid creation of multiple, geologically realistic, figures and models in 2D and 3D using a simple, intuitive interface. The user can sketch in plan- or cross-section view. Geologic rules are used to extrapolate sketched lines in real time to create 3D surfaces. Quantitative analysis can be carried our directly on the models. Alternatively, they can be output as simple figures or imported directly into other modeling tools. The software runs on a tablet PC and can be used in a variety of settings including the office, classroom and field. The speed and ease of use of SBIM enables multiple interpretations to be developed from limited data, uncertainty to be readily appraised, and figures and models to be rapidly updated to incorporate new data or concepts.

  2. Geology of the American Southwest

    NASA Astrophysics Data System (ADS)

    Baldridge, W. Scott

    2004-06-01

    Scott Baldridge presents a concise guide to the geology of the Southwestern U.S. Two billion years of Earth history are represented in the rocks and landscape of the Southwest U.S., creating natural wonders such as the Grand Canyon, Monument Valley, and Death Valley. This region is considered a geologist's "dream", attracting a large number of undergraduate field classes and amateur geologists. The volume will prove invaluable to students and will also appeal to anyone interested in the geology and landscape of the region's National Parks.

  3. Coordinated CRISM and Opportunity Observations to Characterize the Mineralogy and Geologic History of Meridiani Planum Outcrops

    NASA Astrophysics Data System (ADS)

    Arvidson, R. E.

    2011-12-01

    The Opportunity Mars Exploration Rover has traversed over 30 km across Meridiani Planum since January 2004, acquiring numerous remote sensing and in-situ measurements of rocks and soils at dozens of locations. Over the past year Mars Reconnaissance Orbiter CRISM (0.362 to 3.92 micrometer imaging spectrometer) observations have been used to directly support planning of Opportunity traverses and locations for detailed remote sensing and in-situ measurements. As part of these coordinated observations CRISM's gimbaled optics have been used to spatially oversample acquisition of image data in the along-track direction (ATO or along track oversampled observations). This new acquisition mode allows sharpening the spatial detail from the normal ~18 m/pixel observations to values as small as ~6 m/pixel, with due formal consideration of the decrease in S/N with decreasing pixel sizes for retrieval of the 544 band spectra for each pixel. CRISM ATO observations show that mono-hydrated sulfates, most likely kieserite, outcrop on the walls of Victoria crater and the southeastern rim of Santa Maria crater. Unfortunately, the Victoria identifications are on the opposite side of the crater relative to where Opportunity made measurements of Victoria wall rocks. On the other hand, Opportunity was directed to Santa Maria's southeastern rim based on CRISM spectral reflectance data, spending the last solar conjunction period acquiring long-duration in-situ measurements of outcrop that likely carries the mono-hydrated sulfate signature. Additional ATO data collected over the relatively fresh, 2.3 km wide Ada crater located in southeastern Meridiani Planum show a similar mono-hydrated sulfate signature, implying that these deposits are widespread. Further, ATO observations allow detailed mapping of extensive hydrated sulfates in Botany Bay immediately to the south of Cape York, a rim segment of the largely buried, Noachian age Endeavour crater. Opportunity will cross these hydrated

  4. Introductory Geology: Aspects and Options.

    ERIC Educational Resources Information Center

    Bowen, John E.; And Others

    Included are essays presenting diversified views on questions related to problems, procedures and the impact of the Introductory Course Program (ICP) in geology. The papers of this issue deal with such factors as the financial survival in curricular design and introductory course options, the problems of transfer of majors which may place…

  5. Geology on a Sand Budget

    ERIC Educational Resources Information Center

    Kane, Jacqueline

    2004-01-01

    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…

  6. ANNOTATED BIBLIOGRAPHY OF GEOLOGICAL EDUCATION.

    ERIC Educational Resources Information Center

    BERG, J. ROBERT; AND OTHERS

    ARTICLES ABOUT GEOLOGICAL EDUCATION WRITTEN DURING THE PERIOD 1919-62 ARE INCLUDED IN THIS ANNOTATED BIBLIOGRAPHY. RECOMMENDATIONS OF INDIVIDUAL EDUCATORS AND PROFESSIONAL GROUPS FOR THE UNDERGRADUATE AND GRADUATE PREPARATION OF GEOLOGISTS ARE CONTAINED IN MOST OF THE ITEMS. THE ARTICLES WERE ORIGINALLY PUBLISHED IN PROFESSIONAL JOURNALS OR…

  7. 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...

  8. Neutron Absorption in Geological Material

    NASA Astrophysics Data System (ADS)

    Løvhøiden, G.; Andersen, E.

    1990-01-01

    Thermal neutron absorption cross section of geological samples is determined with the steady state neutron source method. Cross section measurements of North Sea sediments demonstrate that also materials with high contents of clay minerals may be investigated with the steady state method.

  9. Infrared Analysis of Geological Materials.

    ERIC Educational Resources Information Center

    Brown, Alan; Clark, E. Roy

    1980-01-01

    Describes the infrared analysis of geological specimens which can form the basis of a laboratory exercise, allowing some minerals to be identified by "fingerprint" technique. Students can gain insight into the concept of symmetry and environment around an atom. (Author/SA)

  10. Mapping the Surficial Geology of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Mosher, D. C.; Jakobsson, M.; Gebhardt, C.; Mayer, L. A.

    2014-12-01

    Surficial geologic mapping of the Arctic Ocean was undertaken to provide a basis for understanding different geologic environments in this polar setting. Mapping was based on data acquired from numerous icebreaker and submarine missions to the polar region. The intent was to create a geologic layer overlying the International Bathymetric Chart of the Arctic Ocean. Analysis of subbottom profiler and multibeam bathymetric data in conjunction with sediment cores and the regional morphology rendered from the IBCAO data were used to map different surficial geologic units. For a relatively small ocean basin, the Arctic Ocean reveals a plethora of margin and basin types reflecting both the complex tectonic origins of the basin and its diverse sedimentation history. Broad and narrow shelves were subjected to a complex ice-margin history in the Quaternary, and bear the sediment types and morphological features as a result. Some shelfal areas are heavily influenced by rivers. Extensive deep water ridges and plateaus are isolated from coastal input and have a long history of hemipelagic deposition. An active spreading ridge and regions of recent volcanism have volcani-clastic and heavily altered sediments. Some regions of the Arctic Ocean are proposed to have been influenced by bolide impact. The flanks of the basins demonstrate complex sedimentation patterns resulting from mass failures and ice-margin outflow. The deep basins of the Arctic Ocean are filled with turbidites resulting from these mass-flows and are interbedded with hemiplegic deposits.

  11. Basic petroleum geology, 2nd ed. , revised

    SciTech Connect

    Link.

    1990-01-01

    This book contains revised and updated material, including approximately 200 additional illustrations and an extensive glossary of terms. A valuable reference for geology students and petroleum professionals, the text presents fundamental concepts of geology in terms of sedimentary deposition, petroleum occurrence, exploration, and recovery. This book contains information on geologic time, historical geology and stratigraphy; Minerals and rocks; Weathering erosion, and deposition; Marine erosion and deposition; Depositional basins; Lacustrine, desert and glacial environments; Subsurface water and diagenesis; Structural geology; petroleum traps; Petroleum and reservoirs; Geological considerations and engineering practices; Rocks, reservoirs, and recovery techniques; Exploration techniques for petroleum; Bibliography Glossary; Index.

  12. Geostatistical applications in petroleum geology and sedimentary geology

    SciTech Connect

    Murray, C.J.

    1992-01-01

    Statistical tools can aid the geologist in understanding geologic data, and in the solution of real-world problems. This thesis examines several tools, concentrating on techniques with wide applicability in sedimentary and petroleum geology. A case study presents the use of geostatistics for mapping hydrocarbon pore volume and risk assessment in an area surrounding Amos Draw field in the northern Powder River basin of Wyoming. The study used sequential Gaussian and indicator simulation techniques, and documents the ability of indicator simulation to incorporate correlated secondary data. Reservoir characterization requires the generation of numerical grids of geologic properties. Because those properties differ for each rock type, one should first simulate the distribution of rock types, and then the distribution of the reservoir properties. This thesis proposes two multivariate statistical techniques, discriminant function analysis and cluster analysis, for the identification of petrophysical rock types in the Muddy Formation at Amos Draw. The geology of those rock types is discussed using core descriptions, thin-sections, and well log data. The rock types were simulated in three dimensions using indicator principal component simulation. The study also used simulated annealing for post-processing of the simulations, incorporating information from the wells on the transition frequencies between the rock types. The third case study used runs analysis for the identification of patterns in bed thickness and grain size in turbidites. Upward-thickening and thinning patterns have been used to assign turbidite sequences to depositional environments, although there has been disagreement on their identification. Runs analysis was applied to a turbidite section in the Sites Formation at Cache Creek, in northern California.

  13. The Geology of the Terrestrial Planets

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  14. Teaching Geology in a Penitentiary Setting.

    ERIC Educational Resources Information Center

    Orr, William N.

    1986-01-01

    Describes geology teaching in a penal institution, considering class offerings, teaching structure, teaching schedule, security, cheating, student characteristics, women prisoners in geology classes, and outside field trips. Sample laboratory schedule is included. (JN)

  15. Amazing Altered Books

    ERIC Educational Resources Information Center

    Kieling, Linda W.

    2006-01-01

    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…

  16. Planetary geology in the 1980s

    NASA Technical Reports Server (NTRS)

    Veverka, J.

    1984-01-01

    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.

  17. U.S. Geological Survey Geologic Carbon Sequestration Assessment

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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

  18. Fractals in geology and geophysics

    NASA Technical Reports Server (NTRS)

    Turcotte, Donald L.

    1989-01-01

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

  19. Geology of the reading prong

    SciTech Connect

    Schutz, D.

    1987-03-01

    For over a billion years the geological terrain now called New Jersey has been the site of unusually high uranium concentrations. Although the highest of these concentrations occurs in the Reading Prong, the area is itself only part of a larger geologic province extending to the northeast and southwest. The rocks in the Reading Prong are not uniformly radioactive. High uranium concentrations tend to be associated with magnetite deposits - metamorphic equivalents of iron-rich formations - and with pegmatites - rocks formed by precipitation from mineralizing solutions in the late phases of granite emplacement. Because of the way they were formed, the uranium-bearing magnetite and pegmatite bodies tend to be long and narrow, and the resulting patterns of radon occurrence can be expected to be the same. This may explain why, in some places, adjacent houses have very different radon concentrations.

  20. Complex Geologic History of Triton

    NASA Technical Reports Server (NTRS)

    1989-01-01

    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.

  1. Geology of central Lake Michigan.

    USGS Publications Warehouse

    Wood, R.J.; Paull, R.A.; Wolosin, C.A.; Friedel, R.J.

    1981-01-01

    The geology beneath central Lake Michigan is interpreted from a synthesis of 1,700 km of continuous seismic reflection profile data, bathymetry, grab samples, and onshore surface and subsurface information. The map of unconsolidated sediment (primarily Pleistocene) shows thicknesses ranging from 180 m in a steep- walled, northeast-trending valley to less than 10 m over a mid-lake topographic high. These are the dominant features developed on the gently eastward-dipping Paleozoic rocks along this part of the western flank of the Michigan basin. Two structural-stratigraphic cross sections of the study area were constructed. The cross sections, grab samples and other information were used to construct a Paleozoic geologic map. Speculations are made about the petroleum potential beneath Lake Michigan. -from Authors

  2. Geologic periodicities and the Galaxy

    NASA Technical Reports Server (NTRS)

    Rampino, Michael R.; Stothers, Richard B.

    1986-01-01

    New geologic and astronomical developments are reviewed that have recently led to the proposal of various Galactic theories to explain the temporal pattern of impact craters on earth. Linear and harmonic time series analyses have revealed that two dominant periodicities about equal to 33 + or - 3 Myr and 260 + or - 25 Myr underlie the geologic record of terrestrial impact cratering and global tectonic phenomena. It is argued that purely terrestrial mechanisms cannot account for the cratering cycles as being preservational artifacts; cratering rather appears to influence tectonism, possibly through perturbations of mantle convection. Galactic models proposed to explain the two long-term periodicities are reviewed critically. The most likely explanation for the 33 Myr cycle involves the comparatively stable half period of vertical oscillation of the solar system about the Galactic plane. The 260 Myr cycle may be related to rare encounters with Galactic spiral arms during the revolution of the solar system around the Galactic center.

  3. Mineral-chemical studies of metamorphosed hydrothermal alteration in the Kristineberg volcanogenic massive sulfide district, Sweden

    NASA Astrophysics Data System (ADS)

    Hannington, Mark D.; Kjarsgaard, Ingrid M.; Galley, Alan G.; Taylor, Bruce

    2003-06-01

    is developed locally in the chlorite-rich pipe at Kristineberg in response to regional thermal metamorphism of highly aluminous alteration in the immediate foot-wall rocks. Spectacular, andalusite-bearing quartz-muscovite schists and quartz-biotite-cordierite schists also occur where the altered felsic volcanic rocks are intruded by the late Revsund granite. However, similar metamorphic mineral growth is not observed where the volcanic rocks at the contact are less altered. Deposits near the top of the felsic volcanic succession are characterized by magnesium-rich chlorite alteration in the foot wall and proximal calc-silicate assemblages (dolomite, calcite, tremolite, ±garnet, ±margarite) where the host sedimentary rocks are carbonate-rich. In general, the calc-silicate alteration is restricted to the immediate hanging wall and zones lateral to the deposits and does not represent a regionally extensive exploration target. The two main ore horizons in the Kristineberg area are not linked by any obvious discordant structures or alteration zones. However, mineral-chemical studies highlight several possible fluid flow pathways leading from the Kristineberg deposit to the Ravliden ore horizon, more than 2 km upsection. Overprinting regional metamorphic minerals have inherited the hydrothermal signature of the ore-related alteration. Electronic Supplementary Material is available at http://dx.doi.org/10.1007/s00126-002-0299-y. On that page (frame on the left side), a link takes you directly to the supplementary material.

  4. 49 CFR 801.59 - Geological records.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Geological records. 801.59 Section 801.59... PUBLIC AVAILABILITY OF INFORMATION Exemption From Public Disclosure § 801.59 Geological records. Pursuant to 5 U.S.C. 552(b)(9), records concerning geological wells are exempt from public disclosure....

  5. 49 CFR 801.59 - Geological records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Geological records. 801.59 Section 801.59... PUBLIC AVAILABILITY OF INFORMATION Exemption From Public Disclosure § 801.59 Geological records. Pursuant to 5 U.S.C. 552(b)(9), records concerning geological wells are exempt from public disclosure....

  6. 49 CFR 801.59 - Geological records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Geological records. 801.59 Section 801.59... PUBLIC AVAILABILITY OF INFORMATION Exemption From Public Disclosure § 801.59 Geological records. Pursuant to 5 U.S.C. 552(b)(9), records concerning geological wells are exempt from public disclosure....

  7. 49 CFR 801.59 - Geological records.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Geological records. 801.59 Section 801.59... PUBLIC AVAILABILITY OF INFORMATION Exemption From Public Disclosure § 801.59 Geological records. Pursuant to 5 U.S.C. 552(b)(9), records concerning geological wells are exempt from public disclosure....

  8. 49 CFR 801.59 - Geological records.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Geological records. 801.59 Section 801.59... PUBLIC AVAILABILITY OF INFORMATION Exemption From Public Disclosure § 801.59 Geological records. Pursuant to 5 U.S.C. 552(b)(9), records concerning geological wells are exempt from public disclosure....

  9. State Geological Surveys and Geoscience Education.

    ERIC Educational Resources Information Center

    Ostrom, Meredith Eggers

    1991-01-01

    State geological surveys have a significant role in geologic education. They are the principal gatherers, evaluators, and distributors of geologic information within their states; and they are in daily contact with the public through state, government, industry, and educator contacts. Many surveys are attempting to disseminate information through…

  10. Measuring Student Understanding of Geological Time

    ERIC Educational Resources Information Center

    Dodick, Jeff; Orion, Nir

    2003-01-01

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

  11. 30 CFR 784.22 - Geologic information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., at a minimum, the following: (1) A description of the geology of the proposed permit and adjacent... mining. This description shall include the areal and structural geology of the permit and adjacent areas... structural geology may affect the occurrence, availability, movement, quantity and quality of...

  12. 30 CFR 784.22 - Geologic information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., at a minimum, the following: (1) A description of the geology of the proposed permit and adjacent... mining. This description shall include the areal and structural geology of the permit and adjacent areas... structural geology may affect the occurrence, availability, movement, quantity and quality of...

  13. 30 CFR 784.22 - Geologic information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., at a minimum, the following: (1) A description of the geology of the proposed permit and adjacent... mining. This description shall include the areal and structural geology of the permit and adjacent areas... structural geology may affect the occurrence, availability, movement, quantity and quality of...

  14. 30 CFR 784.22 - Geologic information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., at a minimum, the following: (1) A description of the geology of the proposed permit and adjacent... mining. This description shall include the areal and structural geology of the permit and adjacent areas... structural geology may affect the occurrence, availability, movement, quantity and quality of...

  15. Learning Geologic Time in the Field.

    ERIC Educational Resources Information Center

    Thomas, Robert C.

    2001-01-01

    Describes a method used to teach the concept of geologic time to introductory geology students using an inquiry-based approach. Students work in teams to obtain rock samples that are used to interpret the geologic history of a region. (SAH)

  16. Geological mapping in West Virginia

    SciTech Connect

    Dean, S.L. . Dept. of Geology); Kulander, B.R. . Dept. of Geological Sciences); Lessing, P. )

    1992-01-01

    Geological mapping at 1:24,000 scale in the Valley and Ridge province of West Virginia is an ongoing program to up-date 75-year old 1:62,500 scale county geological maps. Large-scale topographic maps, remote-sensing imagery, geophysical data, well-log data, and advances in structural concepts provide information leading to thin-skinned tectonic interpretations. The five maps displayed (22 7.5-minute quadrangles) illustrate the complex deformational styles in the Paleozoic section of the Massanutten/Blue Ridge, Waynesboro, and Martinsburg sheets. Detailed field mapping reveals that many previously mapped anticlines, such as Great North Mountain and Adams run, are complex anticlinoria and that large expanses of Lower Mississippian clastics were overlooked in the Sector and Lost River State Park quadrangles. Furthermore, prevalent thrust and strike-slip faulting in the Cambrian-Ordovician carbonates of the Great Valley and extensive folding, faulting, and pre-fold layer-parallel shortening have occurred in the upper sheet to an extent not previously reported. Finally, imbrication of the underlying Waynesboro sheet forms a duplex that defines major anticlinoria and synclinoria in the Valley and Ridge. Complete maps have proven beneficial to government and the public. Examples are the siting of high-yield water wells, delineation of wellheat protection areas, and providing maps suitable for GIS systems. The maps have also been used to organize regional and local field trips and have served as the basis for the further structural and stratigraphic investigations. The West Virginia Geological Survey places high priority on detailed geological mapping. However, continuation of the program is dependent upon adequate funding.

  17. Dione's spectral and geological properties

    USGS Publications Warehouse

    Stephan, K.; Jaumann, R.; Wagner, R.; Clark, R.N.; Cruikshank, D.P.; Hibbitts, C.A.; Roatsch, T.; Hoffmann, H.; Brown, R.H.; Filiacchione, G.; Buratti, B.J.; Hansen, G.B.; McCord, T.B.; Nicholson, P.D.; Baines, K.H.

    2010-01-01

    We present a detailed analysis of the variations in spectral properties across the surface of Saturn's satellite Dione using Cassini/VIMS data and their relationships to geological and/or morphological characteristics as seen in the Cassini/ISS images. This analysis focuses on a local region on Dione's anti-saturnian hemisphere that was observed by VIMS with high spatial resolution during orbit 16 in October 2005. The results are incorporated into a global context provided by VIMS data acquired within Cassini's first 50 orbits. Our results show that Dione's surface is dominated by at least one global process. Bombardment by magnetospheric particles is consistent with the concentration of dark material and enhanced CO2 absorption on the trailing hemisphere of Dione independent of the geology. Local regions within this terrain indicate a special kind of resurfacing that probably is related to large-scale impact process. In contrast, the enhanced ice signature on the leading side is associated with the extended ejecta of the fresh impact crater Creusa (???49??N/76??W). Although no geologically active regions could be identified, Dione's tectonized regions observed with high spatial resolution partly show some clean H2O ice implying that tectonic processes could have continued into more recent times. ?? 2009 Elsevier Inc. All rights reserved.

  18. Pennsylvania's contribution to petroleum geology

    SciTech Connect

    Dickey, P.A.

    1989-09-01

    John F. Carll of the Second Geological Survey of Pennsylvania laid the foundations of both petroleum geology and reservoir engineering. J. P. Lesley, director of the Second Survey, had introduced structure contours when he was working in the anthracite fields. He pointed out that the great oil fields of Pennsylvania were in the only part of the state where there were no anticlines. I. C. White, another geologist with the Second Survey, emphasized the anticlinal theory adopted as a method of prospecting until the discovery of the Cushing field in Oklahoma in 1912. George Ashley, state geologist of Pennsylvanian in the 1930s and 1940s, said that after the gas companies had drilled all the anticlines there would still be the synclines. David White in 1915 noticed the relation between the metamorphosis (rank) of coal and the occurrence of oil and gas. This method (vitrinite reflectance) is now widely applied in the evaluation of basins. In the late 1930s, the resurvey of the Pennsylvania oil regions showed that the reservoirs were shoreline sands, probably barrier islands. In the 1950s the AAPG recommended a study of the recent sediments of the Mississippi delta by Scripps Institute of Oceanography. The ability to recognize depositional environments has caused a revolution in petroleum geology, and recently has been recognized by petroleum engineers as the key to reservoir characterization.

  19. Geologic mapping using thermal images

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  20. Planetary Geology and Geophysics Program

    NASA Technical Reports Server (NTRS)

    McGill, George E.

    2004-01-01

    Geological mapping and topical studies, primarily in the southern Acidalia Planitia/Cydonia Mensae region of Mars is presented. The overall objective was to understand geologic processes and crustal history in the northern lowland in order to assess the probability that an ocean once existed in this region. The major deliverable is a block of 6 1:500,000 scale geologic maps that will be published in 2004 as a single map at 1:1,000,000 scale along with extensive descriptive and interpretive text. A major issue addressed by the mapping was the relative ages of the extensive plains of Acidalia Planitia and the knobs and mesas of Cydonia Mensae. The mapping results clearly favor a younger age for the plains. Topical studies included a preliminary analysis of the very abundant small domes and cones to assess the possibility that their origins could be determined by detailed mapping and remote-sensing analysis. We also tested the validity of putative shorelines by using GIs to co-register full-resolution MOLA altimetry data and Viking images with these shorelines plotted on them. Of the 3 proposed shorelines in this area, one is probably valid, one is definitely not valid, and the third is apparently 2 shorelines closely spaced in elevation. Publications supported entirely or in part by this grant are included.

  1. Global geologic map of Ganymede

    USGS Publications Warehouse

    Collins, Geoffrey C.; Patterson, G. Wesley; Head, James W.; Pappalardo, Robert T.; Prockter, Louise M.; Lucchitta, Baerbel K.; Kay, Johnathan P.

    2014-01-01

    Ganymede is the largest satellite of Jupiter, and its icy surface has been formed through a variety of impact cratering, tectonic, and possibly cryovolcanic processes. The history of Ganymede can be divided into three distinct phases: an early phase dominated by impact cratering and mixing of non-ice materials in the icy crust, a phase in the middle of its history marked by great tectonic upheaval, and a late quiescent phase characterized by a gradual drop in heat flow and further impact cratering. Images of Ganymede suitable for geologic mapping were collected during the flybys of Voyager 1 and Voyager 2 (1979), as well as during the Galileo Mission in orbit around Jupiter (1995–2003). This map represents a synthesis of our understanding of Ganymede geology after the conclusion of the Galileo Mission. We summarize the properties of the imaging dataset used to construct the map, previously published maps of Ganymede, our own mapping rationale, and the geologic history of Ganymede. Additional details on these topics, along with detailed descriptions of the type localities for the material units, may be found in the companion paper to this map (Patterson and others, 2010).

  2. SHARAD Penetrates Only the Youngest Geological Units on Mars

    NASA Astrophysics Data System (ADS)

    Stillman, D.; Grimm, R. E.

    2009-12-01

    The SHAllow RADar (SHARAD) instrument on the Mars Reconnaissance Orbiter was intended to receive echoes from up to 1 km deep in the rocky martian subsurface. Such deep penetration only occurs in the icy polar caps and in certain ice-rich units. In fact, over the majority of the rocky units of Mars, only surface echoes are detected. Therefore, rocky units are more attenuating than expected. To gain insight into the cause of this attenuation, we correlated SHARAD subsurface reflectors with a geologic map of the northern plains of Mars [Tanaka et al., 2005]. Our survey was restricted to this area due to general smoother topography and hence less potential influence of surface scattering (clutter). All released SHARAD data (approximately 1,500 radargrams) overlying the geologic map were individually interpreted. Geologic units were categorized by their map description into ice-rich, pristine volcanic, and water-altered units. The last category comprises units interpreted to be fluvial, lacustrine, or periglacial in origin, as well as volcanic and other units that were subsequently altered by water or ice. Radar reflections in each unit were further categorized as abundant, occasional, or none. We found that abundant reflections are only detected in geologic units that are Amazonian in age, and ice-rich or pristine volcanic. No reflections are seen in water altered units. Occasional reflections are detected in Hesperian-aged pristine volcanic units. We propose two endmember hypotheses for this attenuation behavior, scattering and absorption, but they could act jointly. The young pristine volcanic units that SHARAD penetrates consist of thick (about 50 m) flood basalts or tuff. These units are expected to have cooling joints in them, but little if any other heterogeneity; therefore their scattering loss should be small. With increasing age and thermoelastic stress due to global cooling and contraction, these previously homogeneous volcanics could become increasingly

  3. 77 FR 38318 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ....S. Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological..., Interior. ACTION: Notice of annual meeting: Audio Conference. SUMMARY: Pursuant to Public Law 106-148, the...) 648-6976. SUPPLEMENTARY INFORMATION: Meetings of the National Cooperative Geologic Mapping Program...

  4. 77 FR 6580 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ....S. Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical Data Preservation Program (NGGDPP) Advisory Committee AGENCY: U.S. Geological Survey... Standard Time. The Committee will hear updates on progress of the NCGMP toward fulfilling the purposes...

  5. Element speciation during nuclear glass alteration

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

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

    USGS Publications Warehouse

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

    1972-01-01

    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

  7. Geologic Map of Loudoun County, Virginia

    USGS Publications Warehouse

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

    2006-01-01

    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).

  8. Underground mining and deep geologic disposal - Two compatible and complementary activities

    SciTech Connect

    Rempe, N.T.

    1995-12-31

    Active and mature underground mining districts offer conditions favorable to deep geologic disposal because their geology is known in more detail, the feasibility of underground excavations has already been demonstrated, mining leaves distinctive footprints and records that alert subsequent generations to the anthropogenic alterations of the underground environment, and subsequent exploration and production proceeds with great care and accuracy to locate and generally to avoid old mine workings. Compatibility of mining with deep geologic waste disposal has been proven by decades of experience with safe storage and disposal in former mines and in the mined-out areas of still active mining operations. Mineral extraction around an intended repository reduces the incentive for future disturbance. Incidental features of mineral exploration and extraction such as lost circulation zones, allochthonous backfill, and permanent surface markers can deter future intrusion into a repository. Thus exploration and production of mineral resources should be compatible with, and complementary to, deep geologic waste disposal.

  9. Preliminary Geologic Characterization of West Coast States for Geologic Sequestration

    SciTech Connect

    Larry Myer

    2005-09-29

    Characterization of geological sinks for sequestration of CO{sub 2} in California, Nevada, Oregon, and Washington was carried out as part of Phase I of the West Coast Regional Carbon Sequestration Partnership (WESTCARB) project. Results show that there are geologic storage opportunities in the region within each of the following major technology areas: saline formations, oil and gas reservoirs, and coal beds. The work focused on sedimentary basins as the initial most-promising targets for geologic sequestration. Geographical Information System (GIS) layers showing sedimentary basins and oil, gas, and coal fields in those basins were developed. The GIS layers were attributed with information on the subsurface, including sediment thickness, presence and depth of porous and permeable sandstones, and, where available, reservoir properties. California offers outstanding sequestration opportunities because of its large capacity and the potential of value-added benefits from enhanced oil recovery (EOR) and enhanced gas recovery (EGR). The estimate for storage capacity of saline formations in the ten largest basins in California ranges from about 150 to about 500 Gt of CO{sub 2}, depending on assumptions about the fraction of the formations used and the fraction of the pore volume filled with separate-phase CO{sub 2}. Potential CO{sub 2}-EOR storage was estimated to be 3.4 Gt, based on a screening of reservoirs using depth, an API gravity cutoff, and cumulative oil produced. The cumulative production from gas reservoirs (screened by depth) suggests a CO{sub 2} storage capacity of 1.7 Gt. In Oregon and Washington, sedimentary basins along the coast also offer sequestration opportunities. Of particular interest is the Puget Trough Basin, which contains up to 1,130 m (3,700 ft) of unconsolidated sediments overlying up to 3,050 m (10,000 ft) of Tertiary sedimentary rocks. The Puget Trough Basin also contains deep coal formations, which are sequestration targets and may have

  10. Aerogeophysical measurements of collapse-prone hydrothermally altered zones at Mount Rainier volcano

    USGS Publications Warehouse

    Finn, C.A.; Sisson, T.W.; Deszcz-Pan, M.

    2001-01-01

    Hydrothermally altered rocks can weaken volcanoes, increasing the potential for catastrophic sector collapses that can lead to destructive debris flows1. Evaluating the hazards associated with such alteration is difficult because alteration has been mapped on few active volcanoes1-4 and the distribution and severity of subsurface alteration is largely unknown on any active volcano. At Mount Rainier volcano (Washington, USA), collapses of hydrothermally altered edifice flanks have generated numerous extensive debris flows5,6 and future collapses could threaten areas that are now densely populated7. Preliminary geological mapping and remote-sensing data indicated that exposed alteration is contained in a dyke-controlled belt trending east-west that passes through the volcano's summit3-5,8. But here we present helicopter-borne electromagnetic and magnetic data, combined with detailed geological mapping, to show that appreciable thicknesses of mostly buried hydrothermally altered rock lie mainly in the upper west flank of Mount Rainier. We identify this as the likely source for future large debris flows. But as negligible amounts of highly altered rock lie in the volcano's core, this might impede collapse retrogression and so limit the volumes and inundation areas of future debris flows. Our results demonstrate that high-resolution geophysical and geological observations can yield unprecedented views of the three-dimensional distribution of altered rock.

  11. Aerogeophysical measurements of collapse-prone hydrothermally altered zones at Mount Rainier volcano.

    PubMed

    Finn, C A; Sisson, T W; Deszcz-Pan, M

    2001-02-01

    Hydrothermally altered rocks can weaken volcanoes, increasing the potential for catastrophic sector collapses that can lead to destructive debris flows. Evaluating the hazards associated with such alteration is difficult because alteration has been mapped on few active volcanoes and the distribution and severity of subsurface alteration is largely unknown on any active volcano. At Mount Rainier volcano (Washington, USA), collapses of hydrothermally altered edifice flanks have generated numerous extensive debris flows and future collapses could threaten areas that are now densely populated. Preliminary geological mapping and remote-sensing data indicated that exposed alteration is contained in a dyke-controlled belt trending east-west that passes through the volcano's summit. But here we present helicopter-borne electromagnetic and magnetic data, combined with detailed geological mapping, to show that appreciable thicknesses of mostly buried hydrothermally altered rock lie mainly in the upper west flank of Mount Rainier. We identify this as the likely source for future large debris flows. But as negligible amounts of highly altered rock lie in the volcano's core, this might impede collapse retrogression and so limit the volumes and inundation areas of future debris flows. Our results demonstrate that high-resolution geophysical and geological observations can yield unprecedented views of the three-dimensional distribution of altered rock.

  12. Nasa's Planetary Geologic Mapping Program: Overview

    NASA Astrophysics Data System (ADS)

    Williams, D. A.

    2016-06-01

    NASA's Planetary Science Division supports the geologic mapping of planetary surfaces through a distinct organizational structure and a series of research and analysis (R&A) funding programs. Cartography and geologic mapping issues for NASA's planetary science programs are overseen by the Mapping and Planetary Spatial Infrastructure Team (MAPSIT), which is an assessment group for cartography similar to the Mars Exploration Program Assessment Group (MEPAG) for Mars exploration. MAPSIT's Steering Committee includes specialists in geological mapping, who make up the Geologic Mapping Subcommittee (GEMS). I am the GEMS Chair, and with a group of 3-4 community mappers we advise the U.S. Geological Survey Planetary Geologic Mapping Coordinator (Dr. James Skinner) and develop policy and procedures to aid the planetary geologic mapping community. GEMS meets twice a year, at the Annual Lunar and Planetary Science Conference in March, and at the Annual Planetary Mappers' Meeting in June (attendance is required by all NASA-funded geologic mappers). Funding programs under NASA's current R&A structure to propose geological mapping projects include Mars Data Analysis (Mars), Lunar Data Analysis (Moon), Discovery Data Analysis (Mercury, Vesta, Ceres), Cassini Data Analysis (Saturn moons), Solar System Workings (Venus or Jupiter moons), and the Planetary Data Archiving, Restoration, and Tools (PDART) program. Current NASA policy requires all funded geologic mapping projects to be done digitally using Geographic Information Systems (GIS) software. In this presentation we will discuss details on how geologic mapping is done consistent with current NASA policy and USGS guidelines.

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

    USGS Publications Warehouse

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

    2003-01-01

    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.

  14. Map showing potential metal-mine drainage hazards in Colorado, based on mineral-deposit geology

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Streufert, Randall K.; Smith, Kathleen S.; Smith, Steven M.; Wallace, Alan R.; Toth, Margo I.; Nash, J. Thomas; Robinson, Rob A.; Ficklin, Walter H.; Lee, Gregory K.

    1995-01-01

    This map, compiled by the U.S. Geological Survey (USGS) in cooperation with the Colorado Geological Survey (CGS) and the U. S. Bureau of Land Management (BLM), shows potential mine-drainage hazards that may exist in Colorado metal-mining districts, as indicated by the geologic characteristics of the mineral deposits that occur in the respective districts. It was designed to demonstrate how geologic and geochemical information can be used on a regional scale to help assess the potential for mining-related and natural drainage problems in mining districts, unmined mineralized areas, and surrounding watersheds. The map also provides information on the distribution of different mineral deposit types across Colorado. A GIS (Geographic Information System) format was used to integrate geologic, geochemical, water-quality, climate, landuse, and ecological data from diverse sources. Likely mine-drainage signatures were defined for each mining district based on: (1) a review of the geologic characteristics of the mining district, including mineralogy, trace-element content, host-rock lithology, and wallrock alteration, and; (2) results of site specific studies on the geologic controls on mine-drainage composition.

  15. Geology of the Ar Rahail ancient gold mine, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    White, Willis H.; Samater, Rashid M.; Doebrich, Jeff L.

    1987-01-01

    Pre-existing northwest-trending faults, possibly re-opened by stock emplacement, were invaded by later fluids that precipitated barren quartz veins and, in the adjacent faulted wall rocks, anomalous gold and arsenic. Gold, however, is restricted to the narrow structures, and, although values as much as 4.2 g/t are present, the tonnages are inadequate for profitable mining. No further work is recommended, because the hoped for dissemination of gold between faults does not exist.

  16. Petroleum geology of southwestern Ohio

    SciTech Connect

    Sitler, G.

    1987-09-01

    Approximately 250 wells have been drilled in the 22-county area comprising southwestern Ohio. Despite numerous shows from various zones, no sustained commercial production has been established. Live oil and gas shows have been reported from surface exposures of outcropping Silurian carbonates down to, and including, the Cambrian Mount Simon Sandstone. Several wells have been completed and actually produced hydrocarbons for a short period, but were subsequently abandoned. Despite the lack of established production, the area holds considerable promise as a potential oil and natural gas producing region. Gravity, magnetics, seismic, surface and source rock geochemistry, linear trace analysis, and subsurface computer mapping have all been used to study the structure, stratigraphy, and petroleum geology of the area. Basement geology is complex and has affected sedimentation patterns in the overlying Cambrian rocks. The Grenville-Central Province contact is present in the area and exhibits faulting, mineralization, and possibly plutonism. The Cambrian and Ordovician stratigraphy in the area is relatively simple, with clastics at the base, carbonates in the middle, and a thick shale capping the sequence. Several major facies changes are evident within the section. Structural geology is also fairly simple. However, local discontinuities are apparent and include Precambrian doming and faulting, reactivated faulting, and Knox unconformable surfaces. Potential reservoirs in the area include the Utica Shale, Trenton Limestone, St. Peter Sandstone, Rose Run sandstone, Knox dolomites, Kerbel sandstone, Eau Claire Sandstone, and Mount Simon Sandstone. Favorable source rock geochemistry and the abundance of hydrocarbon shows suggest favorable source rocks to be present. Many different types of traps have been observed.

  17. Muon Tomography for Geological Repositories.

    NASA Astrophysics Data System (ADS)

    Woodward, D.; Kudryavtsev, V.; Gluyas, J.; Clark, S. J.; Thompson, L. F.; Klinger, J.; Spooner, N. J.; Blackwell, T. B.; Pal, S.; Lincoln, D. L.; Paling, S. M.; Mitchell, C. N.; Benton, C.; Coleman, M. L.; Telfer, S.; Cole, A.; Nolan, S.; Chadwick, P.

    2015-12-01

    Cosmic-ray muons are subatomic particles produced in the upper atmosphere in collisions of primary cosmic rays with atoms in air. Due to their high penetrating power these muons can be used to image the content (primarily density) of matter they pass through. They have already been used to image the structure of pyramids, volcanoes and other objects. Their applications can be extended to investigating the structure of, and monitoring changes in geological formations and repositories, in particular deep subsurface sites with stored CO2. Current methods of monitoring subsurface CO2, such as repeat seismic surveys, are episodic and require highly skilled personnel to operate. Our simulations based on simplified models have previously shown that muon tomography could be used to continuously monitor CO2 injection and migration and complement existing technologies. Here we present a simulation of the monitoring of CO2 plume evolution in a geological reservoir using muon tomography. The stratigraphy in the vicinity of the reservoir is modelled using geological data, and a numerical fluid flow model is used to describe the time evolution of the CO2 plume. A planar detection region with a surface area of 1000 m2 is considered, at a vertical depth of 776 m below the seabed. We find that one year of constant CO2 injection leads to changes in the column density of about 1%, and that the CO2 plume is already resolvable with an exposure time of less than 50 days. The attached figure show a map of CO2 plume in angular coordinates as reconstructed from observed muons. In parallel with simulation efforts, a small prototype muon detector has been designed, built and tested in a deep subsurface laboratory. Initial calibrations of the detector have shown that it can reach the required angular resolution for muon detection. Stable operation in a small borehole within a few months has been demonstrated.

  18. Ore metals through geologic history.

    PubMed

    Meyer, C

    1985-03-22

    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.

  19. Chapter 4: Geological Carbon Sequestration

    SciTech Connect

    Friedmann, J; Herzog, H

    2006-06-14

    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 earth's upper crust. This chapter focuses on geological sequestration because it appears to be the most promising large-scale approach for the 2050 timeframe. It does not discuss ocean or terrestrial sequestration. In order to achieve substantial GHG reductions, geological storage needs to be deployed at a large scale. For example, 1 Gt C/yr (3.6 Gt CO{sub 2}/yr) abatement, requires carbon capture and storage (CCS) from 600 large pulverized coal plants ({approx}1000 MW each) or 3600 injection projects at the scale of Statoil's Sleipner project. At present, global carbon emissions from coal approximate 2.5 Gt C. However, given reasonable economic and demand growth projections in a business-as-usual context, global coal emissions could account for 9 Gt C. These volumes highlight the need to develop rapidly an understanding of typical crustal response to such large projects, and the magnitude of the effort prompts certain concerns regarding implementation, efficiency, and risk of the enterprise. The key questions of subsurface engineering and surface safety associated with carbon sequestration are: (1) Subsurface issues: (a) Is there enough capacity to store CO{sub 2} where needed? (b) Do we understand storage mechanisms well enough? (c) Could we establish a process to certify injection sites with our current level of understanding? (d) Once injected, can we monitor and verify the movement of subsurface CO{sub 2}? (2) Near surface issues: (a) How might the siting of new coal plants be influenced by the distribution of storage sites? (b) What is the probability of CO{sub 2} escaping from injection sites? What are the attendant risks? Can we detect leakage if it occurs? (3) Will surface leakage negate or reduce the

  20. The Extraction of Altered Minerals by use of Hyperspectral and Aster Data and Their Comparison Research in Beketan, Altyn

    NASA Astrophysics Data System (ADS)

    Yi, H.; Li, J. Q.; Ren, G. L.; Yang, M.; Han, H. H.; Gao, T.; Yang, J. L.

    2016-11-01

    Hyperspectral remote sensing technology has played an important role in the field of geological application in recent years. Based on the reflectance of typical altered minerals and the spectral characteristics of rocks, we tried to identify and extract the altered minerals such as calcite, dolomite, epidote, chlorite, moscovite, limonite, hematite, etc. by using of CASI/SASI data in Beketan, Altyn. Moreover, we extracted Mg-OH/CO32-/Al-OH/Fe3+/Ferric oxide from Aster data by the ratio method. Combined with known geological background and the field investigation, we found that the extracted altered mineral information was consistent with the actual distribution of the field. The altered mineral information extracted by Hyperspectral data dispalyed more mineral distribution in details. It showed that the hyperspectral remote sensing technology could provide accurate hydrothermal altered mineral information which is helpful for geological mapping work.

  1. Geology of the Uranian satellites

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  2. Geological considerations in hazardouswaste disposal

    USGS Publications Warehouse

    Cartwright, K.; Gilkeson, R.H.; Johnson, T.M.

    1981-01-01

    Present regulations assume that long-term isolation of hazardous wastes - including toxic chemical, biological, radioactive, flammable and explosive wastes - may be effected by disposal in landfills that have liners of very low hydraulic conductivity. In reality, total isolation of wastes in humid areas is not possible; some migration of leachate from wastes buried in the gound will always occur. Regulations should provide performance standards applicable on a site-by-site basis rather than rigid criteria for site selection and design. The performance standards should take into account several factors: (1) the categories, segregation, degradation and toxicity of the wastes; (2) the site hydrogeology, which governs the direction and rate of contaminant transport; (3) the attenuation of contaminants by geochemical interactions with geologic materials; and (4) the release rate of unattenuated pollutants to surface or groundwater. An adequate monitoring system is essential. The system should both test the extent to which the operation of the site meets performance standards and provide sufficient warning of pollution problems to allow implementation of remedial measures. In recent years there has been a trend away from numerous, small disposal sites toward fewer and larger sites. The size of a disposal site should be based on the attenuation capacity of the geologic material, which has a finite, though generally not well-defined, limit. For slowly degradable wastes, engineered sites with leachate-collection systems appear to be only a temporary solution since the leachate collected will also require final disposal. ?? 1981.

  3. Geology of central Lake Michigan

    SciTech Connect

    Wold, R.J.; Paull, R.A.; Wolosin, C.A.; Friedel, R.J.

    1981-09-01

    The geology beneath Lake Michigan between 43/sup 0/00' and 44/sup 0/00'N and between 86/sup 0/30' and 87/sup 0/40' W is interpreted from a synthesis of 1,700 km of continuous seismic reflection profile data, bathymetry, grab samples, and onshore surface and subsurface information. The continuous seismic reflection profiles and bathymetry provided information for maps of unconsolidated sediment thickness and Paleozoic bedrock topography. Two structural-stratigraphic cross sections of the study area were constructed by utilizing a composite subsurface-surface section for eastern Wisconsin and two control wells in western Michigan. The cross sections, grab samples previously described in the literature, the bedrock topographic map, and published maps were used to construct a Paleozoic geologic map for central Lake Michigan. Rocks from Middle Silurian through Early Mississippian age form subcrops beneath the study area, whereas rocks of Early Silurian, Ordovician, and Late Cambrian age are present at greater depth. The Upper Cambrian rocks unconformably overlie Precambrian igneous and metamorphic rocks. The structural-stratigraphic cross sections also allow speculation about the petroleum potential beneath Lake Michigan. The possibility of oil occurrences within the Silurian is enhanced by major east-west facies changes, and other horizons with promise are present in Devonian and Ordovician rocks. Although Michigan and Wisconsin laws currently prohibit petroleum exploration in Lake Michigan, it is an area with future potential.

  4. Global Geological Mapping of Enceladus

    NASA Astrophysics Data System (ADS)

    Crow-Willard, Emma; Pappalardo, R. T.

    2010-10-01

    Global geological mapping of Enceladus highlights 3 distinct tectonized regions, which we term trailing hemisphere terrain (THT), leading hemisphere terrain (LHT), and south polar terrain (SPT). All three terrains are framed by curvilinear terrain units, and all have comparable areal extent with the south polar terrain being the smallest. In its central region, the THT contains a unit consisting of smooth materials and long shallow troughs, which is nearly identical to materials of the SPT just northward of the "tiger stripes” and with similar orientation of SPT troughs. This suggests that these shallow troughs may have formed in a similar manner to the SPT fractures. In contrast to the SPT, the THT contains a ridged unit of large dorsa, cross-cutting a striated plains unit, all within the THT's frame of curvilinear terrain. The LHT contains a disorganized network of troughs similar to parts of the SPT. The LHT also has units with polygons of sub-parallel troughs suggesting shearing. Heavily cratered terrain reaches around the saturnian and anti-saturnian sides of the satellite, abutting the south polar terrain. We recognize a total of 13 different geological units within the three tectonized regions and the cratered terrain of Enceladus. Differences in the local terrains might be explained by combinations of local diapiric uplift, collapse, and satellite reorientation to form the tectonized terrains, tied to episodic localized heat flow related to tidal stresses.

  5. Geology of the Hawaiian islands

    USGS Publications Warehouse

    Stearns, Harold T.

    1946-01-01

    A brief summary of the geography, climate, and geomorphology is given. Streams develop slowly after the extinction of a volcano because of the high permeability of the rock. Once established they cut rapidly because of the steep slopes and fractured condition of the rock. Stream erosion varies enormously on different slopes of the same mountain due to the great differences in rainfall and to other causes. Six reasons are given for the development of amphitheater-headed valleys. Marine erosion has formed cliffs as much as 1,000 feet high on the leeward side and 3,000 feet high on the windward side of some of the domes. The islands have undergone a complex series of emergences and submergences leaving marine fossiliferous limestone up to 1,070 feet above sea level and valleys drowned more than 1,200 feet. Twelve terrace levels are recognized. Some are definitely eustatic.A synopsis is given of the present knowledge of the geology of each volcanic mountain, as well as a table of the rock units, and geologic maps of all major islands. The volcanoes pass through four major phases between birth and extinction and are built around one minor and two major rift zones. The volcanoes began their history above sea level in the Tertiary. Most of them became dormant either before or during the early Quaternary. Activity was renewed in the late Quaternary. Mauna Kea was glaciated in the late Pleistocene. The character of each islet in the archipelago is tabulated.

  6. Geology and tectonics of Japanese islands: A review - The key to understanding the geology of Asia

    NASA Astrophysics Data System (ADS)

    Wakita, Koji

    2013-08-01

    complexes in the Japanese Islands are of Permian, Jurassic and Cretaceous-Paleogene age. These accretionary complexes became altered locally to low-temperature and high-pressure metamorphic, or high-temperature and low-pressure metamorphic rocks. Medium-pressure metamorphic rocks are limited to the Unazuki and Higo belts. Major plutonism occurred in Paleozoic, Mesozoic and Cenozoic time. Early Paleozoic Cambrian igneous activity is recorded as granites in the South Kitakami Belt. Late Paleozoic igneous activity is recognized in the Hida Belt. During Cretaceous to Paleogene time, extensive igneous activity occurred in Japan. The youngest granite in Japan is the Takidani Granite intruded at about 1-2 Ma. During Cenozoic time, the most important geologic events are back-arc opening and arc-arc collision. The major back-arc basins are the Sea of Japan and the Shikoku and Chishima basins. Arc-arc collision occurred between the Honshu and Izu-Bonin arcs, and the Honshu and Chishima arcs.

  7. Structure and geological evolution of the island of Ponza, Italy: inferences from geological and gravimetric data

    NASA Astrophysics Data System (ADS)

    Bellucci, F.; Grimaldi, M.; Lirer, L.; Rapolla, A.

    1997-10-01

    A geological and a geophysical survey have been carried out at Ponza Island, Tyrrhenian sea, Italy. Geological and structural data allowed to identify three main tectonic systems: NW-SE, NE-SW and E-W trending. The first one is related to a pre-volcanic tectonic event, probably linked to the Pliocene extensional activity of the Tyrrhenian evolution; the other two systems affected the volcanic units in two different stages of the Lower Pleistocene, the earlier one after the rhyolitic hyaloclastic formation (HF) emplacement and the later one after the emplacement of older trachytic pyroclastic deposits (Lower Pyroclastic Units—LPU). The latter event was followed by the emersion of the whole Ponza area, as testified by a marked erosional surface and marine terrace deposits cropping out at the top of LPU. The Upper Pyroclastic Units (UPU) represent the younger trachytic activity of the island (1.3 Myr) and do not show evidence of tectonic activity. The NW-SE-trending tectonic system probably assisted the rhyolitic magma rise, while the NE-SW- and E-W-trending systems mainly assisted the trachytic magma rise, responsible for the explosive and effusive activity in the southern area and for the hydrothermal fluids that caused alteration processes in the northern area. A 161-station gravimetric survey was carried out on the island and surrounding islets. The geological data and the gravimetric survey have been used to propose a 2.5 D model in which rhyolitic hyaloclastic deposits (ρ = 1.7 g cm -3) overlay an articulated Meso-Cenozoic sedimentary substratum (ρ = 2.6 g cm -3) laying at a depth to 300 m below sea level. Both formations are crossed by rhyolitic dykes (ρ = 2.4 g cm -3) which mark feeder fractures. In the M. Guardia area, where a maximum is present, this model accounts for the presence of a horst of the rigid basement, a shallow trachytic lava flow and its feeder (ρ = 2.8 g cm -3).

  8. Coarse muscovite veins and alteration deep in the Yerington batholith, Nevada: insights into fluid exsolution in the roots of porphyry copper systems

    NASA Astrophysics Data System (ADS)

    Runyon, Simone E.; Steele-MacInnis, Matthew; Seedorff, Eric; Lecumberri-Sanchez, Pilar; Mazdab, Frank K.

    2017-02-01

    Veins and pervasive wall-rock alteration composed of coarse muscovite±quartz±pyrite are documented for the first time in a porphyritic granite at Luhr Hill in the Yerington District, Nevada. Coarse muscovite at Luhr Hill occurs at paleodepths of 6-7 km in the roots of a porphyry copper system and crops out on the scale of tens to hundreds of meters, surrounded by rock that is unaltered or variably altered to sodic-calcic assemblages. Coarse muscovite veins exhibit a consistent orientation, subvertical and N-S striking, which structurally restores to subhorizontal at the time of formation. Along strike, coarse muscovite veins swell from distal, millimeter-thick muscovite-only veinlets to proximal, centimeter-thick quartz-sulfide-bearing muscovite veins. Crosscutting relationships between coarse muscovite veins, pegmatite dikes, and sodic-calcic veins indicate that muscovite veins are late-stage magmatic-hydrothermal features predating final solidification of the Luhr Hill porphyritic granite. Fluid inclusions in the muscovite-quartz veins are high-density aqueous inclusions of 3-9 wt% NaCl eq. and <1 mol% CO2 that homogenize between 150 and 200 °C, similar to fluid inclusions from greisen veins in Sn-W-Mo vein systems. Our results indicate that muscovite-forming fluids at Luhr Hill were mildly acidic, of low to moderate salinity and sulfur content and low CO2 content, and that muscovite in deep veins and alteration differs in texture, composition, and process of formation from sericite at shallower levels of the hydrothermal system. Although the definition of greisen is controversial, we suggest that coarse muscovite alteration is more similar to alteration in greisen-type Sn-W-Mo districts worldwide than to sericitic alteration at higher levels of porphyry copper systems. The fluids that form coarse muscovite veins and alteration in the roots of porphyry copper systems are distinct from fluids that formed copper ore or widespread, shallower, acidic alteration

  9. Attention Alters Perceived Attractiveness.

    PubMed

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another.

  10. Regionalization in geology by multivariate classification

    USGS Publications Warehouse

    Harff, Jan; Davis, J.C.

    1990-01-01

    The concept of multivariate classification of "geological objects" can be combined with the concept of regionalized variables to yield a procedure for typification of geological objects, such as rock units, well records, or samples. Numerical classification is followed by subdivision of the area of investigation, and culminates in a regionalization or mapping of the classification onto the plane. Regions are subdivisions of the map area which are spatially contiguous and relatively homogeneous in their geological properties. The probability of correct classification of each point within a region as being part of that region can be assessed in terms of Bayesian probability as a space-dependent function. The procedure is applied to subsurface data from western Kansas. The geologic properties used are quantitative variables, and relationships are expressed by Mahalanobis' distances. These functions could be replaced by other metrics if qualitative or binary data derived from geological descriptions or appraisals were included in the analysis. ?? 1990 International Association for Mathematical Geology.

  11. GeoSciML version 3: A GML application for geologic information

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    orientation (e.g. 'miarolitic cavities'). The Earth material package allows for the description of both individual components, such as minerals, and compound materials, such as rocks or unconsolidated materials. Provision is made for alteration, weathering, metamorphism, particle geometry, fabric, and petrophysical descriptions. Mapped features describe the shape of the geological features using standard GML geometries, such as polygons, lines, points or 3D volumes. Geological events provide the age, process and environment of formation of geological features. The Earth Resource section includes features to represent mineral occurrences and mines and associated human activities independently. This addition allows description of resources and reserves that can comply with national and internationally accepted reporting codes. GeoSciML v3 is under consideration as the data model for INSPIRE annex 2 geologic reporting in Europe.

  12. Chromite alteration processes within Vourinos ophiolite

    NASA Astrophysics Data System (ADS)

    Grieco, Giovanni; Merlini, Anna

    2012-09-01

    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.

  13. County digital geologic mapping. Final report

    SciTech Connect

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

    1995-12-31

    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.

  14. Geologic Mapping in Southern Margaritifer Terra

    NASA Technical Reports Server (NTRS)

    Irwin, R. P., III; Grant, J. A.

    2010-01-01

    Margaritifer Terra records a complex geologic history [1-5], and the area from Holden crater through Ladon Valles, Ladon basin, and up to Morava Valles is no exception [e.g., 6-13]. The 1:500,000 geologic map of MTM quadrangles -15027, -20027, -25027, and -25032 (Figs. 1 and 2 [14]) identifies a range of units that delineate the history of water-related activity and regional geologic context.

  15. USGS Western Coastal and Marine Geology Team

    USGS Publications Warehouse

    Johnson, Sam; Gibbons, Helen

    2007-01-01

    The Western Coastal and Marine Geology Team of the U.S. Geological Survey (USGS) studies the coasts of the western United States, including Alaska and Hawai‘i. Team scientists conduct research, monitor processes, and develop information about coastal and marine geologic hazards, environmental conditions, habitats, and energy and mineral resources. This information helps managers at all levels of government and in the private sector make informed decisions about the use and protection of national coastal and marine resources.

  16. Geology of Mount Rainier National Park, Washington

    USGS Publications Warehouse

    Fiske, Richard S.; Hopson, Clifford Andrae; Waters, Aaron Clement

    1963-01-01

    Mount Rainier National Park includes 378 square miles of rugged terrain on the west slope of the Cascade Mountains in central Washington. Its mast imposing topographic and geologic feature is glacier-clad Mount Rainier. This volcano, composed chiefly of flows of pyroxene andesite, was built upon alt earlier mountainous surface, carved from altered volcanic and sedimentary rocks invaded by plutonic and hypabyssal igneous rocks of great complexity. The oldest rocks in the park area are those that make up the Olmnapecosh Formation of late Eocene age. This formation is more than 10,000 feet thick, and consists almost entirely of volcanic debris. It includes some lensoid accumulations of lava and coarse mudflows, heaped around volcanic centers., but these are surrounded by vastly greater volumes of volcanic clastic rocks, in which beds of unstratified coarse tuff-breccia, about 30 feet in average thickness, alternate with thin-bedded breccias, sandstones, and siltstones composed entirely of volcanic debris. The coarser tuff-breccias were probably deposited from subaqueous volcanic mudflows generated when eruption clouds were discharged directly into water, or when subaerial ash flows and mudflows entered bodies of water. The less mobile mudflows and viscous lavas built islands surrounded by this sea of thinner bedded water-laid clastics. In compostion the lava flows and coarse lava fragments of the Ohanapecosh Formation are mostly andesite, but they include less abundant dacite, basalt, and rhyolite. The Ohanapecosh Formation was folded, regionally altered to minerals characteristic of the zeolite facies of metamorphism, uplifted, and deeply eroded before the overlying Stevens Ridge Formation of Oligocene or early Miocene age was deposited upon it. The Stevens Ridge rocks, which are about 3,000 feet in maximum total thickness, consist mainly of massive ash flows. These are now devitrified and altered, but they originally consisted of rhyodacite pumice lapilli and glass

  17. DIGITAL GEOLOGIC MAP OF THE UNITED STATES.

    USGS Publications Warehouse

    Fulton, Patricia

    1983-01-01

    The geologic map of the United States was published in 1974 by the U. S. Geological Survey. This major publication contains an enormous amount of information on the surficial geology of the United States. Many geologists have used this map as a research tool. Most have needed information from only specific parts of the map, and have manually extracted data from these areas. These data have then been combined with other geological information, much of which - especially that concerning minerals and energy - either is already in machine-readable computer files or is rapidly being converted to that form.

  18. Provincial geology and the Industrial Revolution.

    PubMed

    Veneer, Leucha

    2006-06-01

    In the early nineteenth century, geology was a new but rapidly growing science, in the provinces and among the gentlemen scientists of London, Oxford and Cambridge. Industry, particularly mining, often motivated local practical geologists, and the construction of canals and railways exposed the strata for all to see. The most notable of the early practical men of geology was the mineral surveyor William Smith; his geological map of England and Wales, published in 1815, was the first of its kind. He was not alone. The contributions of professional men, and the provincial societies with which they were connected, are sometimes underestimated in the history of geology.

  19. Geologic review. Better regulation through interagency cooperation

    USGS Publications Warehouse

    Johnston, John E.; Rives, James D.; Soileau, David M.

    1989-01-01

    The Geologic Review procedure was developed by the Louisiana Geological Survey (LGS) in 1982 for the Louisiana Coastal Management Division. It consists of a thorough review of oil and gas well applications involving impact to environmentally sensitive areas such as wetlands. The applicant attends a meeting with a geologist and a petroleum engineer from the LGS who review the relevant geologic, engineering and economic data and make a recommendation as to the technical and economic feasibility of reducing or avoiding environmental impact by either moving the well to a geologically equivalent location, directionally drilling the well, or accessing the proposed location by a different access route or methodology than that proposed.

  20. Geology of interior cratonic sag basins

    SciTech Connect

    Leighton, M.W.; Eidel, J.J.; Kolata, D.R.; Oltz, D.F. )

    1990-05-01

    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.

  1. Geologic research at The Geysers

    SciTech Connect

    Hulen, J.B.; Moore, J.N.; Nielson, D.L.

    1996-04-10

    Geologic research at The Geysers vapor-dominated geothermal field during the past year has yielded new information on the nature of steam-reservoir porosity and permeability; the origin of the caprock; mechanisms of lateral sealing; the evolution of The Geysers hydrothermal system; and specific reservoir controls in and immediately above {open_quotes}the felsite{close_quotes}, an hypabyssal, batholith-sized pluton largely responsible for The Geysers` existence. Our research has shown that (1) fluid conduits above the felsite may be dominantly vuggy, high-angle hydrothermal veins; (2) latest-stage hydrothermal calcite in such veins may seal them at the margins of the steam reservoir; mixed-layer clays are probably the corresponding seals in the caprock; (3) steam entries in the felsite are concentrated along the top of the youngest intrusive phase in the pluton - a 1 m.y.-old granodiorite; (4) steam entries in the felsite show a negative correlation with massive borosilicate enrichments.

  2. Geological remote sensing in Africa

    NASA Technical Reports Server (NTRS)

    Sabins, Floyd F., Jr.; Bailey, G. Bryan; Abrams, Michael J.

    1987-01-01

    Programs using remote sensing to obtain geologic information in Africa are reviewed. Studies include the use of Landsat MSS data to evaluate petroleum resources in sedimentary rock terrains in Kenya and Sudan and the use of Landsat TM 30-m resolution data to search for mineral deposits in an ophiolite complex in Oman. Digitally enhanced multispectral SPOT data at a scale of 1:62,000 were used to map folds, faults, diapirs, bedding attitudes, and stratigraphic units in the Atlas Mountains in northern Algeria. In another study, SIR-A data over a vegetated and faulted area of Sierra Leone were compared with data collected by the Landsat MSS and TM systems. It was found that the lineaments on the SIR-A data were more easily detected.

  3. Geology of the Bighorn Mountains

    USGS Publications Warehouse

    Darton, N.H.

    1906-01-01

    There are extensive, forests in the mountains, which are now included in a Government forest reserve, but their timber is not of great value. Much of the area below timber line contains an abundance of luxuriant grasses and other plants, which afford excellent pasturage for stock, and large herds of sheep and cattle are ranged in the region during the short summer season. Game is moderately abundant, and most of the streams contain large numbers of trout. The region is one of great interest geologically on account of its variety of sedimentary rocks, interesting structure, and remarkably instructive glacial features. The central area, with its high peaks, presents alpine scenery of notable character. Doubtless in the future the region will be extensively visited by tourists, hunters, and geologists.

  4. 9th Caribbean Geological Conference

    NASA Astrophysics Data System (ADS)

    Draper, Gren

    The ninth in a series of Caribbean Geological Conferences, which are held every 3 or 4 years, took place in Santo Domingo, capital of the Dominican Republic, from the 15th to 26th of August 1980. The conference, which was sponsored by the government of the Dominican Republic and the Universidad Catolica Madre y Maestra, was preceded by 2 days of field trips and was opened by President Antonio Guzman on the evening of the 17th of August. Generous support was provided by Alcoa Exploration Co., Falconbridge Dominicana, and Rosario Dominicana.Geologists and geophysicists from 25 countries presented about 130 papers on a wide variety of topics ranging from geophysics to paleontology. While the whole Caribbean area was discussed, there was special emphasis on the northern Caribbean and Hispaniola, as befitted the site of the conference. The contribution of workers from the Dirección General de Mineriá was particularly notable.

  5. Measuring Geologic Time on Mars

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Recent images from Mars show compelling evidence of near-surface flowing water, aeolian activity slope processes, and ice cap evolution that underscores the dynamic geologic history of the planet. Establishing an accurate chronology for Martian planetary features is critical for addressing fundamental questions about the evolution of the planet's surface and atmosphere and the differentiation of its interior. For example, how long was standing water on the surface? If life did evolve on Mars, did it occur before or after the evolution of life on Earth? These are arguably some of the most profound questions currently being asked by the planetary science community. Yet answers will not be forthcoming without an absolute chronology of Mars history, enabling the construction of a timescale comparable to Earth's. Discussion of methods for establishing such a chronology is particularly timely in light of new missions to Mars that are being planned to return in situ measurements or samples to Earth.

  6. Geologic mapping using LANDSAT data

    NASA Technical Reports Server (NTRS)

    Siegal, B. S.; Abrams, M. J.

    1976-01-01

    The feasibility of automated classification for lithologic mapping with LANDSAT digital data was evaluated using three classification algorithms. The two supervised algorithms analyzed, a linear discriminant analysis algorithm and a hybrid algorithm which incorporated the Parallelepiped algorithm and the Bayesian maximum likelihood function, were comparable in terms of accuracy; however, classification was only 50 per cent accurate. The linear discriminant analysis algorithm was three times as efficient as the hybrid approach. The unsupervised classification technique, which incorporated the CLUS algorithm, delineated the major lithologic boundaries and, in general, correctly classified the most prominent geologic units. The unsupervised algorithm was not as efficient nor as accurate as the supervised algorithms. Analysis of spectral data for the lithologic units in the 0.4 to 2.5 microns region indicated that a greater separability of the spectral signatures could be obtained using wavelength bands outside the region sensed by LANDSAT.

  7. Impact of advanced fuel cycles on uncertainty associated with geologic repositories

    SciTech Connect

    Rechard, Rob P.; Lee, Joon; Sutton, Mark; Greenberg, Harris R.; Robinson, Bruce A.; Nutt, W. Mark

    2013-07-01

    This paper provides a qualitative evaluation of the impact of advanced fuel cycles, particularly partition and transmutation of actinides, on the uncertainty associated with geologic disposal. Based on the discussion, advanced fuel cycles, will not materially alter (1) the repository performance (2) the spread in dose results around the mean (3) the modeling effort to include significant features, events, and processes in the performance assessment, or (4) the characterization of uncertainty associated with a geologic disposal system in the regulatory environment of the United States. (authors)

  8. Geology of the Mahd Adh Dhahab District, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Afifi, A.M.

    1990-01-01

    Major-element data show that the Mahd Group was produced from separate basaltic and dacitic-rhyolitic magmas that overlapped without mixing. The alkalis and alkaline-earth elements were particularly mobile during metamorphism (which caused widespread albitization of feldspars) and also during hydrothermal alteration (which added secondary microcline). This mobility adversely affected rubidium-strontium whole-rock systematics, which makes whole-rock isochron dates obtained from these rocks questionable. The new geological data presented here are combined with the geochronologic data of Calvez and Kemp (1982) to re-interpret the geologic history of this area.

  9. Geology of McLaughlin Crater, Mars: A Unique Lacustrine Setting with Implications for Astrobiology

    NASA Technical Reports Server (NTRS)

    Michalski, J. R.; Niles, P. B.; Rogers, A. D.; Johnson, S. S.; Ashley, J. W.; Golombek, M. P.

    2016-01-01

    McLaughlin crater is a 92-kmdiameter Martian impact crater that contained an ancient carbonate- and clay mineral-bearing lake in the Late Noachian. Detailed analysis of the geology within this crater reveals a complex history with important implications for astrobiology [1]. The basin contains evidence for, among other deposits, hydrothermally altered rocks, delta deposits, deep water (>400 m) sediments, and potentially turbidites. The geology of this basin stands in stark contrast to that of some ancient basins that contain evidence for transient aqueous processes and airfall sediments (e.g. Gale Crater [2-3]).

  10. Geologic Mapping of V-19

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    A geologic map of the Sedna Planitia (V-19) quadrangle is being completed at 1:5,000,000 scale as part of the NASA Planetary Geologic Mapping Program, and will be submitted for review by September 2010. Overview: The Sedna Planitia quadrangle (V-19) extends from 25 N - 50 N latitude, 330 - 0 longitude. The quadrangle contains the northernmost portion of western Eistla Regio and the Sedna Planitia lowlands. Sedna Planitia consists of low-lying plains units, with numerous small volcanic edifices including shields, domes and cones. The quadrangle also contains several tholi, the large flowfield Neago Fluctus, the Manzan-Gurme Tesserae, and Zorile Dorsa and Karra-mahte Fossae which run NW-SE through the southwestern part of the quadrangle. There are six coronae in the quadrangle (Table 1), the largest of which is Nissaba (300 km x 220 km), and there are fourteen impact craters (Table 2). The V-19 quadrangle contains a variety of mappable volcanic landforms including two shield volcanoes (Evaki Tholus and Toci Tholus) and the southern portion of a large flow field (Neago Fluctus). A total of sixteen units associated with volcanoes have been mapped in this quadrangle, with multiple units mapped at Sif Mons, Sachs Patera and Neago Fluctus. An oddly textured, radarbright flow is also mapped in the Sedna plains, which appears to have originated from a several hundred kilometer long fissure. The six coronae within V-19 have a total of eighteen associated flow units. Several edifice fields are also mapped, in which the small volcanic edifices both predate and postdate the other units. Impact crater materials are also mapped.

  11. Petroleum geology of western Antarctica

    SciTech Connect

    Kingston, J. )

    1990-05-01

    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.

  12. Homo Sapiens as Geological Agents

    NASA Astrophysics Data System (ADS)

    Holloway, T.; Bedsworth, L. W.; Caldeira, K.; Rosenzweig, C.; Kelley, G.; Rosenzweig, C.; Caldeira, K.; Bedsworth, L. W.; Holloway, T.; Purdy, J. S.; Vince, G.; Syvitski, J. A.; Bondre, N. R.; Kelly, J.; Vince, G.; Seto, K. C.; Steffen, W.; Oreskes, N.

    2015-12-01

    In the 18th and 19th centuries, earth scientists came to understand the magnitude and power of geological and geophysical processes. In comparison, the activities of humans seemed paltry if not insignificant. With the development of radiometric dating in the 20th century, scientists realized that human history was but a miniscule part of Earth history. Metaphors to this effect abounded, and filled textbooks: If Earth history were a 24-hour day, human history would not occupy even the final second. If Earth history were a yardstick, the human portion would not even be visible to the naked eye. Generations of scientists were taught that one of the principal contributions of geology, qua science, was the demonstration of our insignificance. The Anthropocene concept disrupts this. To affirms its existence is to insist that human activities compete in scale and significance with other Earth processes, and may threaten to overwhelm them. It also inverts our relation to normative claims. For more than a century earth scientists and evolutionary biologists insisted that their theories were descriptive and not normative—that there was no moral conclusion to be drawn from either planetary or human evolution. Now, we confront the suggestion that there is a moral component to our new paradigm: we can scarcely claim that humans are disrupting the climate, destroying biodiversity, and acidifying the oceans without implying that there is something troubling about these developments. Thus, the Anthropocene concept suggests both a radical redefinition of the scope of Earth science, and a radical reconsideration of the place of normative judgments in scientific work.

  13. Geology and religion in Portugal

    PubMed Central

    Carneiro, Ana; Simoes, Ana; Diogo, Maria Paula; Mota, Teresa Salomé

    2013-01-01

    This paper addresses the relationship between geology and religion in Portugal by focusing on three case studies of naturalists who produced original research and lived in different historical periods, from the eighteenth to the twentieth century. Whereas in non-peripheral European countries religious themes and even controversies between science and religion were dealt with by scientists and discussed in scientific communities, in Portugal the absence of a debate between science and religion within scientific and intellectual circles is particularly striking. From the historiographic point of view, in a country such as Portugal, where Roman Catholicism is part of the religious and cultural tradition, the influence of religion in all aspects of life has been either taken for granted by those less familiar with the national context or dismissed by local intellectuals, who do not see it as relevant to science. The situation is more complex than these dichotomies, rendering the study of this question particularly appealing from the historiographic point of view, geology being by its very nature a well-suited point from which to approach the theme. We argue that there is a long tradition of independence between science and religion, agnosticism and even atheism among local elites. Especially from the eighteenth century onwards, they are usually portrayed as enlightened minds who struggled against religious and political obscurantism. Religion—or, to be more precise, the Roman Catholic Church and its institutions—was usually identified with backwardness, whereas science was seen as the path to progress; consequently men of science usually dissociated their scientific production from religious belief.

  14. Proterozoic geology and ore deposits of Arizona

    USGS Publications Warehouse

    Karlstrom, Karl E.

    1991-01-01

    Proterozoic rocks in Arizona have been the focus of interest for geologists since the late 1800's. Early investigations, led by the U.S. Geological Survey, focused on the extensive ore deposits hosted by Proterozoic rocks. By the 1960's, these studies, combined with theses from academic institutions and the efforts of the Arizona Geological Survey, had produced a rich data base of geologic maps, primarily of the central part of the Transition Zone. The chronological significance of these maps became much better known with the application of U-Pb geochronology by L.Y. Silver and his students starting in the 1960's. The 1970's and early 1980's were marked by numerous contributions from Masters and Ph.D students at a variety of academic institutions, and continued work by the U.S. Geological Survey. Interest in ore deposits persisted and there was an increasing interest in interpretation of the tectonic history of Proterozoic rocks in terms of plate tectonic models, as summarized in papers by Phillip Anderson, Ed DeWitt, Clay Conway, Paul Lindberg, and J.L Anderson in the 1989 Arizona Geological Society Digest 17: "Geologic Evolution of Arizona". The present volume: "Proterozoic Geology and Ore deposits of Arizona" builds upon A.G.S. Digest 17, and presents the results of geologic investigations from the latter part of the 1980's. A number of the papers are condensed versions of MS theses done by students at Northern Arizona University. These papers are based upon 1:10,000 mapping and structural analysis of several areas in Arizona. The geologic maps from each of these studies are available separately as part of the Arizona Geological Survey Contributed Map Series. These detailed maps, plus the continuing mapping efforts of the U.S.G.S. and students at other academic institutions, form an ever improving data base for continuing attempts to understand the Proterozoic geology and ore deposits of Arizona

  15. Identification of Crystalline Minerals in Volcanic Alteration Products and Applications to the Surface of Mars

    NASA Technical Reports Server (NTRS)

    Bishop, J. L.; Madsen, M. B.; Murad, E.; Wagner, P. A.

    2000-01-01

    Visible, infrared and Mossbauer spectra have been measured for fine-grained alteration products of volcanic tephra and ash. Comparison of the spectral and chemical properties for different size separates and related samples provides information about the crystalline materials in these samples and how they may have formed. Hydrothermal processes can increase the alteration rates of the primary minerals and glass and provide S, Fe and/or water for formation of sulfates and hydrated minerals. Identification of crystalline alteration minerals on Mars may indicate hydrothermal alteration and sites of interesting geologic processes.

  16. Survey on Undergraduate Education in Geology. Higher Education Surveys Report, Survey Number 15--Geology.

    ERIC Educational Resources Information Center

    White, Patricia E.; Lewis, Laurie L.

    In 1991, a survey questionnaire concerning undergraduate education in geology was sent to a nationally representative sample of 597 four-year colleges and universities. Of these, 275 had an undergraduate geology department or a department with a geology program, and met the criteria for inclusion in the study. Responses were received from 262 of…

  17. Timescales and conditions for the aqueous alteration of chondrites

    NASA Astrophysics Data System (ADS)

    Jilly, Christine E.

    It has become well-recognized that water played a critical role in the early geological evolution of materials through observation of hydrated phases in chondritic meteorites. However, details about the mechanism, timing, and conditions of aqueous alteration are poorly constrained. This dissertation investigates water-driven processes in Renazzo-like (CR) carbonaceous chondrites, with some comparison to the heavily altered and Mighei-like (CM) chondrites. CR chondrites were chosen as the focus of this study, as they are the only chondrite group to range from practically anhydrous to completely hydrated, providing petrographic context for the aqueous alteration process. The central goal of the thesis is to elucidate the complete mechanism of aqueous alteration, from primary anhydrous components to secondary minerals. This research uses a variety of micro-analytical techniques to address three main objectives: 1) to detail the petrographic context, 2) to quantify the onset and duration of alteration using radiometric dating, and 3) to constrain the fluid chemistry and conditions for aqueous alteration. On a microscopic scale, fine-grained matrices and glassy mesostases were the first phases to become altered, allowing for elemental transport over short distances (< 100 microns). As alteration progressed, the iron-metal was oxidized, and silicate phenocrysts were pseudomorphically replaced. 53Mn-53 Cr radiometric dating of secondary carbonates in CR chondrites show that aqueous alteration began quickly after accretion of the parent body, ~4 Myr after the beginning of the Solar System. This is contemporaneous with dolomite formation in the CM chondrite Sutter's Mill and with carbonate formation in other CM chondrites. However, the calcite age from a heavily hydrated CR lithology indicates that late-stage alteration occurred ~12 Myr after the beginning of the Solar System. The oxygen isotopic compositions of magnetite and carbonate minerals reveal that altering fluid

  18. GEOLOGICAL AND THERMODYNAMIC ASPECTS OF LUNAR ROCKS

    DTIC Science & Technology

    Geological and themodynamic spects of lunar rocks are studied. Several basic problems of lunar geology are examined with the main purpose of...emphasis on probable composition. Important problems related to the structural pattern of the Moon are discussed. A special study is devoted to the

  19. American Geological Education in the Eighteenth Century.

    ERIC Educational Resources Information Center

    Corgan, James X.

    1987-01-01

    Traces the development of the study of geology and geological education in the United States during the 1700's. Addresses the influences of world travel, agriculture, and medicine on the inclusion of earth science into college curricula and self-instruction "civility books." (TW)

  20. Wyoming Geology and Geography, Unit I.

    ERIC Educational Resources Information Center

    Robinson, Terry

    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…

  1. Geology of the Phase II System

    SciTech Connect

    Laney, R.; Laughlin, A. William

    1980-11-19

    This is a report on the analysis of EE-2 cuttings and thin sections, geologic characterization of the Phase II system, comparison with Phase 1, and geologic speculations and recommendations concerning Phase II. The EE-2 litholog has been included in the pocket.

  2. Terrain Models in Field Geology Courses.

    ERIC Educational Resources Information Center

    Whittecar, G. Richard

    1984-01-01

    Describes a terrain model for geologic mapping which, when combined with exercises in rock description, Brunton compass manipulation, orienteering, and geologic report writing, allows students to refine skills needed for summer field camp. Advantages and limitations of the model and its use in a field course are also discussed. (BC)

  3. Abstracts for the Planetary Geology Field Conference

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  4. Geologic maps of Pacific basin and rim

    SciTech Connect

    Craddock, C.

    1986-07-01

    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.

  5. The Earth's Gravity and Its Geological Significance.

    ERIC Educational Resources Information Center

    Cook, A. H.

    1980-01-01

    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)

  6. Reports of Planetary Geology Program, 1982

    NASA Technical Reports Server (NTRS)

    Holt, H. E. (Compiler)

    1982-01-01

    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.

  7. SRS Geology/Hydrogeology Environmental Information Document

    SciTech Connect

    Denham, M.E.

    1999-08-31

    The purpose of the Savannah River Site Geology and Hydrogeology Environmental Information Document (EID) is to provide geologic and hydrogeologic information to serve as a baseline to evaluate potential environmental impacts. This EID is based on a summary of knowledge accumulated from research conducted at the Savannah River Site (SRS) and surrounding areas.

  8. Digital geologic and geophysical data of Bangladesh

    USGS Publications Warehouse

    Persits, Feliks M.; Wandrey, C.J.; Milici, R.C.; Manwar, Abdullah

    1997-01-01

    The data set for these maps includes arcs, polygons, and labels that outline and describe the general geologic age and geophysical fields of Bangladesh. Political boundaries are provided to show the general location of administrative regions and state boundaries. Major base topographic data like cities, rivers, etc. were derived from the same paper map source as the geology.

  9. Advances in planetary geology, volume 2

    NASA Technical Reports Server (NTRS)

    1986-01-01

    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.

  10. Geology highlights for Ride the Rockies 2010

    USGS Publications Warehouse

    Slate, J.L.; Hess, Amber; Van Sistine, D.R.

    2010-01-01

    The author provides a brief description of the geology along the route for each day of the ride, from June 13 through June 19, 2010. Ride the Rockies begins in Grand Junction, with stops in Delta, Ouray, Durango, Pagosa Springs, Alamosa, and ends in Salida, Colorado. A small, generalized geologic map also is shown.

  11. Geology Highlights for Ride the Rockies 2009

    USGS Publications Warehouse

    Slate, Janet

    2009-01-01

    The author provides a brief description of the geology along the route for each day of the ride, from June 14 through June 19, 2009. Ride the Rockies begins and ends in Glenwood Springs, with stops in Hotchkiss, Gunnison, Salida, Leadville, Aspen, and back to Glenwood Springs, Colorado. A small, generalized geologic map also is shown.

  12. Geology highlights, Ride the Rockies 2011

    USGS Publications Warehouse

    Slate, Janet L.

    2011-01-01

    The author provides a brief description of the geology along the route for each day of the ride, from June 12 through June 17, 2011. Ride the Rockies begins in Crested Butte, Colorado, with stops in Buena Vista, Edwards, Steamboat Springs, Granby, and Georgetown. A small, generalized geologic map also is shown.

  13. Status of geologic/environmental characterizations

    SciTech Connect

    1980-12-08

    Studies within the NWTS program directed ultimately at siting one or more radioactive waste repositories consist principally of geologic and environmental characterizations. A draft criteria document has been developed which addresses both geologic and environmental characteristics of any potential site. Several media have been identified as having generic features that could make them acceptable as host media for geologic repositories. Evaluations of these media are being carried out by relating them to the draft criteria document and are currently in various stages of the screening process. The end result will be the identification of at least four sites within the contiguous United States which would be suitable for construction of a repository. The following nine presentations were made: (1) Status of Geologic/Environmental Characterization Studies of Gulf Coast Interior Salt Dome Basins; (2) Status of Geological/Environmental Characterization Studies in the Parodox Basin; (3) Nuclear Waste Isolation Studies of the Palo Duro and Dalhart Basins, Texas Panhandle, FY 1980; (4) Geologic Investigations for Nuclear Waste Repository Sites in Columbia River Basalt - Hanford Site; (5) Method for Screening for Repository Locations on and Contiguous to the Nevada Test Site; (6) Nationwide Review of Shales and Other Argillaceous Strata; (7) Geological Survey Program for Identification of Suitable Geohydrologic Environments for the Disposal of High-Level Radioactive Waste; (8) National Geologic/Environmental Screening for Repositories; (9) States of Characterizations.

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

    SciTech Connect

    Fraser Goff; George Guthrie

    1999-06-01

    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.

  15. The topology of geology 1: Topological analysis

    NASA Astrophysics Data System (ADS)

    Thiele, Samuel T.; Jessell, Mark W.; Lindsay, Mark; Ogarko, Vitaliy; Wellmann, J. Florian; Pakyuz-Charrier, Evren

    2016-10-01

    Topology has been used to characterise and quantify the properties of complex systems in a diverse range of scientific domains. This study explores the concept and applications of topological analysis in geology. We have developed an automatic system for extracting first order 2D topological information from geological maps, and 3D topological information from models built with the Noddy kinematic modelling system, and equivalent analyses should be possible for other implicit modelling systems. A method is presented for describing the spatial and temporal topology of geological models using a set of adjacency relationships that can be expressed as a topology network, thematic adjacency matrix or hive diagram. We define three types of spatial topology (cellular, structural and lithological) that allow us to analyse different aspects of the geology, and then apply them to investigate the geology of the Hamersley Basin, Western Australia.

  16. North Dakota geology school receives major gift

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-10-01

    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.

  17. Geologic Map of the Umiat Quadrangle, Alaska

    USGS Publications Warehouse

    Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.

    2004-01-01

    This geologic map of the Umiat quadrangle is a compilation of previously published USGS geologic maps and unpublished mapping done for the Richfield Oil Corporation. Geologic mapping from these three primary sources was augmented with additional unpublished map data from British Petroleum Company. This report incorporates recent revisions in stratigraphic nomenclature. Stratigraphic and structural interpretations were revised with the aid of modern high-resolution color infrared aerial photographs. The revised geologic map was checked in the field during the summers of 2001 and 2002. The geologic unit descriptions on this map give detailed information on thicknesses, regional distributions, age determinations, and depositional environments. The paper version of this map is available for purchase from the USGS Store.

  18. Mapping Vesta: A Geological Overview

    NASA Astrophysics Data System (ADS)

    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

    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

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

    USGS Publications Warehouse

    Peters, Stephen G.

    2003-01-01

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

  20. Global Warming in Geologic Time

    SciTech Connect

    David Archer

    2008-02-27

    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.

  1. (abstract) Topographic Signatures in Geology

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.; Evans, Diane L.

    1996-01-01

    Topographic information is required for many Earth Science investigations. For example, topography is an important element in regional and global geomorphic studies because it reflects the interplay between the climate-driven processes of erosion and the tectonic processes of uplift. A number of techniques have been developed to analyze digital topographic data, including Fourier texture analysis. A Fourier transform of the topography of an area allows the spatial frequency content of the topography to be analyzed. Band-pass filtering of the transform produces images representing the amplitude of different spatial wavelengths. These are then used in a multi-band classification to map units based on their spatial frequency content. The results using a radar image instead of digital topography showed good correspondence to a geologic map, however brightness variations in the image unrelated to topography caused errors. An additional benefit to the use of Fourier band-pass images for the classification is that the textural signatures of the units are quantative measures of the spatial characteristics of the units that may be used to map similar units in similar environments.

  2. Geology of Lofn Crater, Callisto

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Heiner, Sarah; Klemaszewski, James E.

    2001-01-01

    Lofn crater is a 180-km-diameter impact structure in the southern cratered plains of Callisto and is among the youngest features seen on the surface. The Lofn area was imaged by the Galileo spacecraft at regional-scale resolutions (875 m/pixel), which enable the general geology to be investigated. The morphology of Lofn crater suggests that (1) it is a class of impact structure intermediate between complex craters and palimpsests or (2) it formed by the impact of a projectile which fragmented before reaching the surface, resulting in a shallow crater (even for Callisto). The asymmetric pattern of the rim and ejecta deposits suggests that the impactor entered at a low angle from the northwest. The albedo and other characteristics of the ejecta deposits from Lofn also provide insight into the properties of the icy lithosphere and subsurface configuration at the time of impact. The "target" for the Lofn impact is inferred to have included layered materials associated with the Adlinda multiring structure northwest of Loh and ejecta deposits from the Heimdall crater area to the southeast. The Lofn impact might have penetrated through these materials into a viscous substrate of ductile ice or possibly liquid water. This interpretation is consistent with models of the current interior of Callisto based on geophysical information obtained from the Galileo spacecraft.

  3. Global Warming in Geologic Time

    SciTech Connect

    Archer, David

    2008-02-27

    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.

  4. Global Warming in Geologic Time

    ScienceCinema

    David Archer

    2016-07-12

    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.

  5. Global Geological Map of Venus

    NASA Astrophysics Data System (ADS)

    Ivanov, M. A.

    2008-09-01

    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

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

    USGS Publications Warehouse

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

    2011-01-01

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

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

    USGS Publications Warehouse

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

    2010-01-01

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

  8. Geology and geochemistry of Summitville, Colorado: an epithermal acid sulfate deposit in a volcanic dome

    USGS Publications Warehouse

    Gray, J.E.; Coolbaugh, M.F.

    1994-01-01

    Geologic studies during recent open-pit mining at Summitville, Colorado, have provided new information on an epithermal acid sulfate Au-Ag-Cu deposit formed in a volcanic dome. Geologic mapping, geochemical studies of whole-rock samples from blast holes, and geologic and geochemical traverse studies refine the details of the evolution of the Summitville deposit. Six distinct events followed emplacement of the quartz latite volcanic dome and define the development of the Summitville deposit: 1) an early stage of acid sulfate alteration, 2) subsequent Cu sulfide and gold mineralization, 3) widespread hydrothermal brecciation, 4) volumetrically minor, base metal sulfide-bearing barite veining, 5) volumetrically minor, kaolinite matrix brecciation, and finally, 6) supergene oxidation. -from Authors

  9. Reservoir geology using 3D modelling tools

    SciTech Connect

    Dubrule, O.; Samson, P.; Segonds, D.

    1996-12-31

    The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological {open_quotes}objects{close_quotes} with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.

  10. Reservoir geology using 3D modelling tools

    SciTech Connect

    Dubrule, O. ); Samson, P. ); Segonds, D. )

    1996-01-01

    The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological [open quotes]objects[close quotes] with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.

  11. Geologic and structural map of eastern Asia

    SciTech Connect

    Letouzey, J.; Sage, L.

    1986-07-01

    A synthesis of the onshore and offshore geologic data of eastern Asia, prepared by the Institut Francais du Petrole (IFP), has allowed the construction of geologic and structural maps for this region. These maps include three color sheets (scale = 1:2.5 million) and three plates of geologic and structural cross sections. Located between lat. 4/sup 0/ and 35/sup 0/N, and long. 106/sup 0/ and 132/sup 0/E, the maps cover the following geographic areas: East and South China Sea, Sulu Sea, West Philippine basin and onshore neighboring terrains, Kyushu and Ryukyu Islands, the China margin, Taiwan Island, Vietnam, North West Borneo, and the Philippines. The maps synthesize seismic interpretations, oil well data, geologic work in south Japan, Taiwan, Borneo, and the Philippines, and recent data published between 1976 and 1985. Twenty-four geologic cross sections (scale = 1:1.25 million, vertical exaggeration x 6) intersect ocean margins, important basins, and the different structural domains. They are based on seismic profiles, well data, and available onshore and offshore geologic data. These cross sections show basement composition and structures, different tectonic and sedimentary domains, and the structure and thickness of different sedimentary deposits (such as age, unconformities, and geologic structures). Maps and cross sections will be published in early 1987.

  12. Context of ancient aqueous environments on Mars from in situ geologic mapping at Endeavour Crater

    USGS Publications Warehouse

    Crumpler, L.S.; Arvidson, R. E.; Bell, J.; Clark, B. C.; Cohen, B. A.; Farrand, W. H.; Gellert, Ralf; Golombek, M.; Grant, J. A.; Guinness, E.; Herkenhoff, Kenneth E.; Johnson, J. R.; Jolliff, B.; Ming, D. W.; Mittlefehldt, D. W.; Parker, T.; Rice, J. W.; Squyres, S. W.; Sullivan, R.; Yen, A. S.

    2015-01-01

    Using the Mars Exploration Rover Opportunity, we have compiled one of the first field geologic maps on Mars while traversing the Noachian terrain along the rim of the 22 km diameter Endeavour Crater (Latitude −2°16′33″, Longitude −5°10′51″). In situ mapping of the petrographic, elemental, structural, and stratigraphic characteristics of outcrops and rocks distinguishes four mappable bedrock lithologic units. Three of these rock units predate the surrounding Burns formation sulfate-rich sandstones and one, the Matijevic Formation, represents conditions on early Mars predating the formation of Endeavour Crater. The stratigraphy assembled from these observations includes several geologic unconformities. The differences in lithologic units across these unconformities record changes in the character and intensity of the Martian aqueous environment over geologic time. Water circulated through fractures in the oldest rocks over periods long enough that texturally and elementally significant alteration occurred in fracture walls. These oldest pre-Endeavour rocks and their network of mineralized and altered fractures were preserved by burial beneath impact ejecta and were subsequently exhumed and exposed. The alteration along joints in the oldest rocks and the mineralized veins and concentrations of trace metals in overlying lithologic units is direct evidence that copious volumes of mineralized and/or hydrothermal fluids circulated through the early Martian crust. The wide range in intensity of structural and chemical modification from outcrop to outcrop along the crater rim shows that the ejecta of large (>8 km in diameter) impact craters is complex. These results imply that geologic complexity is to be anticipated in other areas of Mars where cratering has been a fundamental process in the local and regional geology and mineralogy.

  13. Context of ancient aqueous environments on Mars from in situ geologic mapping at Endeavour Crater

    NASA Astrophysics Data System (ADS)

    Crumpler, L. S.; Arvidson, R. E.; Bell, J.; Clark, B. C.; Cohen, B. A.; Farrand, W. H.; Gellert, R.; Golombek, M.; Grant, J. A.; Guinness, E.; Herkenhoff, K. E.; Johnson, J. R.; Jolliff, B.; Ming, D. W.; Mittlefehldt, D. W.; Parker, T.; Rice, J. W., Jr.; Squyres, S. W.; Sullivan, R.; Yen, A. S.

    2015-03-01

    Using the Mars Exploration Rover Opportunity, we have compiled one of the first field geologic maps on Mars while traversing the Noachian terrain along the rim of the 22 km diameter Endeavour Crater (Latitude -2°16'33", Longitude -5°10'51"). In situ mapping of the petrographic, elemental, structural, and stratigraphic characteristics of outcrops and rocks distinguishes four mappable bedrock lithologic units. Three of these rock units predate the surrounding Burns formation sulfate-rich sandstones and one, the Matijevic Formation, represents conditions on early Mars predating the formation of Endeavour Crater. The stratigraphy assembled from these observations includes several geologic unconformities. The differences in lithologic units across these unconformities record changes in the character and intensity of the Martian aqueous environment over geologic time. Water circulated through fractures in the oldest rocks over periods long enough that texturally and elementally significant alteration occurred in fracture walls. These oldest pre-Endeavour rocks and their network of mineralized and altered fractures were preserved by burial beneath impact ejecta and were subsequently exhumed and exposed. The alteration along joints in the oldest rocks and the mineralized veins and concentrations of trace metals in overlying lithologic units is direct evidence that copious volumes of mineralized and/or hydrothermal fluids circulated through the early Martian crust. The wide range in intensity of structural and chemical modification from outcrop to outcrop along the crater rim shows that the ejecta of large (>8 km in diameter) impact craters is complex. These results imply that geologic complexity is to be anticipated in other areas of Mars where cratering has been a fundamental process in the local and regional geology and mineralogy.

  14. Geology Before Pluto: Pre-Encounter Considerations

    NASA Technical Reports Server (NTRS)

    Moore, Jeffrey M.

    2014-01-01

    Pluto, its large satellite Charon, and its four known satellites represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula, and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Modeling of the interior suggests that geologic activity may have been to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. However, the putative indicators of Pluto's geologic history are inconclusive and unspecific. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observations. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system's geologic history. The cameras of New Horizons will provide robust data sets that should be immanently amenable to geological analysis of the Pluto System's landscapes. In this talk, we begin with a brief discussion of the planned observations by New Horizons' cameras that will bear most directly on geological interpretability. Then I will broadly review major geological processes that could potentially operate of the surfaces of Pluto and its moons. I will first survey exogenic processes (i.e., those for which energy for surface modification is supplied externally to the planetary surface): impact cratering, sedimentary processes (including volatile migration) and the work of wind. I will conclude with an assessment of prospects for endogenic activity

  15. Geology Before Pluto: Pre-encounter Considerations

    NASA Astrophysics Data System (ADS)

    Moore, J. M.

    2014-12-01

    Pluto, its large satellite Charon, and its four small known satellites represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique, lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Modeling of the interior suggests that geologic activity may have been significant to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. However, these putative indicators of Pluto's geologic history are inconclusive and unspecific. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observation. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system's geologic history. The cameras of New Horizons will provide robust data sets that should be immanently amenable to geological analysis of the Pluto system's landscapes. In this talk, we begin with a brief discussion of the planned observations by the New Horizons cameras that will bear most directly on geological interpretability. Then I will broadly review major geological processes that could potentially operate on the surfaces of Pluto and its moons. I will first survey exogenic processes (i.e., those for which energy for surface modification is supplied externally to the planetary surface): impact cratering, sedimentary processes (including volatile migration), and the work of wind. I will conclude with an assessment of the

  16. Use of Library Readings to Augment Conventional Geology Instruction.

    ERIC Educational Resources Information Center

    Nold, John Lloyd

    1989-01-01

    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)

  17. The geology of kimberlite pipes of the Ekati property, Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Nowicki, Tom; Crawford, Barbara; Dyck, Darren; Carlson, Jon; McElroy, Ross; Oshust, Peter; Helmstaedt, Herb

    2004-09-01

    This paper reviews key characteristics of kimberlites on the Ekati property, NWT, Canada. To date 150 kimberlites have been discovered on the property, five of which are mined for diamonds. The kimberlites intrude Archean basement of the central Slave craton. Numerous Proterozoic diabase dykes intrude the area. The Precambrian rocks are overlain by Quaternary glacial sediments. No Phanerozoic rocks are present. However, mudstone xenoliths and disaggregated sediment within the kimberlites indicate that late-Cretaceous and Tertiary cover (likely <200 m) was present at the time of emplacement. The Ekati kimberlites range in age from 45 to 75 Ma. They are mostly small pipe-like bodies (surface area mostly <3 ha but up to 20 ha) that typically extend to projected depths of 400-600 m below current surface. Pipe morphologies are strongly controlled by joints and faults. The kimberlites consist primarily of variably bedded volcaniclastic kimberlite (VK). This is dominated by juvenile constituents (olivine and lesser kimberlitic ash) and variable amounts of exotic sediment (primarily mud), with minor amounts of xenolithic wall-rock material (generally <5%). Kimberlite types include: mud-rich resedimented VK (mRVK); olivine-rich VK (oVK); sedimentary kimberlite; primary VK (PVK); tuffisitic kimberlite (TK) and magmatic kimberlite (MK). The presence and arrangement of these rock types varies widely. The majority of bodies are dominated by oVK and mRVK, but PVK is prominent in the lower portions of certain kimberlites. TK is rare. MK occurs primarily as precursor dykes but, in a few cases, forms pipe-filling intrusions. The internal geology of the kimberlites ranges from simple single-phase pipes (RVK or MK), to complex bodies with multiple, distinct units of VK. The latter include pipes infilled with steep, irregular VK blocks/wedges and at least one case in which the pipe is occupied by well-defined sub-horizontal VK phases, including a unique, 100-m-thick graded sequence

  18. Developing Medical Geology in Uruguay: A Review

    PubMed Central

    Mañay, Nelly

    2010-01-01

    Several disciplines like Environmental Toxicology, Epidemiology, Public Health and Geology have been the basis of the development of Medical Geology in Uruguay during the last decade. The knowledge and performance in environmental and health issues have been improved by joining similar aims research teams and experts from different institutions to face environmental problems dealing with the population’s exposure to metals and metalloids and their health impacts. Some of the Uruguayan Medical Geology examples are reviewed focusing on their multidisciplinary approach: Lead pollution and exposed children, selenium in critically ill patients, copper deficiency in cattle and arsenic risk assessment in ground water. Future actions are also presented. PMID:20623004

  19. Developing medical geology in Uruguay: a review.

    PubMed

    Mañay, Nelly

    2010-05-01

    Several disciplines like Environmental Toxicology, Epidemiology, Public Health and Geology have been the basis of the development of Medical Geology in Uruguay during the last decade. The knowledge and performance in environmental and health issues have been improved by joining similar aims research teams and experts from different institutions to face environmental problems dealing with the population's exposure to metals and metalloids and their health impacts. Some of the Uruguayan Medical Geology examples are reviewed focusing on their multidisciplinary approach: Lead pollution and exposed children, selenium in critically ill patients, copper deficiency in cattle and arsenic risk assessment in ground water. Future actions are also presented.

  20. Mineral resources, geological structures, and landform surveys

    NASA Technical Reports Server (NTRS)

    Short, N. M.

    1974-01-01

    Since March 1973 there has been a shift in ERTS results in geology from the initial show-and-tell stage to a period in which scientific studies predominated, and now to an emphasis on effective applications having economic benefits and clearcut relevance to national needs. Many years will be spent on geological tasks resulting from ERTS alone; reconnaissance mapping in inaccessible regions, map revisions, regional or synoptic analysis of crustal fractures, assessment of dynamic surficial processes, systematic search for mineral wealth, use of sophisticated enhancement techniques, recognition of potential geologic hazards, and many more applications that still need to be defined.

  1. Geology of Massachusetts and Rhode Island

    USGS Publications Warehouse

    Emerson, Benjamin Kendall

    1917-01-01

    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.

  2. Genetically Altered Plant Species

    NASA Technical Reports Server (NTRS)

    2003-01-01

    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.

  3. [Unusual myopic fundus alteration].

    PubMed

    Münzenberg, C; Paulsen, F; Kalinski, T; Dmitriew, A; Duncker, G I W; Sel, S

    2009-07-01

    A 44-year-old female patient reported a "black dot" which had been in front of the right eye for more than 4 days and which moved together with eye movements. The optical coherence tomography (OCT) image of the right macula showed large cystic cavities and thickening within the retinal pigment epithelium (RPE) near the fovea centralis as well as small bore cystic alterations, which indicated an event in the region of the choroid. Fluorescein angiography and indocyanine green angiography excluded choroidal neovascularization (CNV). The diagnosis revealed a broad superficial choroidal blood vessel mimicking a subretinal hemorrhage.

  4. Endeavour basalt geology and petrology

    NASA Astrophysics Data System (ADS)

    Gill, J. B.; Stakes, J.; Ramos, F.; Michael, P.; Stakes, D.

    2005-12-01

    We report major and trace element and isotope data from 250 basalt samples recently collected by submersible from the axial valley and flanks of the Endeavour segment of the Juan de Fuca Ridge. Off-axis volcanism is abundant on both flanks which are mirror images of one another geologically. Axial valley walls up to 1 km off axis appear to be steps of in tact but variably fractured sheet, lobate, and hackly lava flows similar to the youngest lavas seen in collapse features in the axis. Coverage by pillow terrane increases with distance off axis and coverage becomes complete after 1 km. The similarity of the two flanks suggests that the currently asymmetric axial magma chamber (van Ark et al., 2004) may be shorter-lived than the off-axis volcanism. MgO contents range from 6.0-8.5% and generally are lower on the flanks consistent with consistently cooler chamber edges there. La/Yb ratios vary 3-fold within 100 m in the axial valley, with normalized La/Sm = 0.8-2.5 in contrast to constant Sr and Nd isotopes. However, Th/U and 230Th/232Th ratios vary only slightly in the axial valley, which may enable dating of off-axis samples. H2O/Ce is less than 170, typical of values throughout much of the Pacific. Variations in depth and degree of melting, and in source composition, are implied. At times, these heterogeneities escaped homogenization in axial magma chambers. Cl concentrations and Cl/K ratios are surprisingly low considering the active hydrothermal systems in close proximity and the potential for brine incorporation into the magma chamber.

  5. Geology of the Henry Mountains

    USGS Publications Warehouse

    Gilbert, G.K.

    1877-01-01

    If these pages fail to give a correct account of the structure of the Henry Mountains the fault is mine and I have no excuse. In all the earlier exploration of the Rocky Mountain Region, as well as in much of the more recent survey, the geologist has merely accompanied the geographer and has had no voice in the determination of either the route or the rate of travel. When the structure of a mountain was in doubt he was rarely able to visit the points which should resolve the doubt, but was compelled to turn regretfully away. Not so in the survey of the Henry Mountains. Geological exploration had shown that they were well disposed for examination, and that they promised to give the key to a type of structure which was at best obscurely known; and I was sent by Professor Powell to make a study of them, without restriction as to my order or method. I was limited only in time, the snow stopping my work two months after it was begun. Two months would be far too short a period in which to survey a thousand square miles in Pennsylvania or Illinois, but among the Colorado Plateaus it proved sufficient. A few comprehensive views from mountain tops gave the general distribution of the formations, and the remainder of the time was spent in the examination of the localities which best displayed the peculiar features of the structure. So thorough was the display and so satisfactory the examination, that in preparing my report I have felt less than ever before the desire to revisit the field and prove my conclusions by more extended observation.

  6. Petroleum geology of East Siberia

    SciTech Connect

    Clarke, J.W.

    1986-05-01

    The unmetamorphosed geologic section of the East Siberian region consists of upper Proterozoic clastic and carbonate sediments; Cambrian evaporites, carbonates, and black shales; Ordovician to permian clastic and carbonate sediments; Triassic basaltic flows and intrusives; and Jurassic and Cretaceous clastic sediments. During the Cambrian, a barrier reef extended across the region. Salt and anhydrite were deposited in the vast lagoon to the southwest behind this reef. The structure is typical of platforms; broad, gentle warps are complicated by smaller highs. The total area of East Siberia that is potentially favorable for oil and gas is 3.23 million km/sup 2/ (1.24 million mi/sup 2/). Deposits in the Lena-Tunguska province are in stratigraphic traps in Proterozoic to Cambrian clastic and carbonate sediments sealed by Cambrian salt and in anticlinal structures in areas of salt tectonics. Source beds seem to be Proterozoic. Pools in the Khatanga-Vilyuy province are in anticlines in Triassic, Jurassic, and Cretaceous clastic sedimentary rocks. Source beds are Permian carbonaceous shale. Most discoveries have been of gas; however, several fields have oil rings. The traps appear to have been filled by oil at one time. Undiscovered recoverable petroleum resources of East Siberia are assessed, at 90% probability, within the range of 2.2-14.6 billion bbl of oil and 72-278 tcf of gas. Mean estimates are 7.3 billion bbl of oil and 158 tcf of gas, respectively. Gas-hydrate deposits in the Lena-Vilyuy province, where permafrost is more than 400 m thick, are estimated to contain 27 tcf of possibly recoverable gas.

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

    NASA Technical Reports Server (NTRS)

    1991-01-01

    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.

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

    SciTech Connect

    Not Available

    1991-01-01

    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, US 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.

  9. Contribution of LANDSAT-4 thematic mapper data to geologic exploration

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  10. Proposed geologic model based on geophysical well logs

    SciTech Connect

    Diaz C, S.; Puente C, I.; de la Pena L, A.

    1981-01-01

    An investigation of the subsurface based on a qualitative interpretation of well logs was carried out at Cerro Prieto to obtain information on the distribution of the different lithofacies that make up a deltaic depositional system. The sedimentological interpretation derived from the resistivity and spontaneous potential are shown in several cross-sections of the field. In addition to the sedimentological interpretation, a map of the structural geology of the region based on well logs and available geophysical information was prepared, including the results of gravity and seismic refraction surveys. The depth to the zone of hydrothermal alteration described by Elders (1980) was found by means of temperature, electrical, and radioactive logs. Two maps showing the configuration of the top of this anomaly show a clear correlation with the gravity anomalies found in the area.

  11. Nuclear fuel corrosion over millennia interpreted using geologic data

    SciTech Connect

    Pearcy, E.C.; Manaktala, H.K.

    1994-12-31

    Corrosion of nuclear fuel over the 10,000 year regulatory period in a geologic repository will be a function of physical characteristics (e.g., crystallinity, crystal sizes, crystal forms) and chemical characteristics (e.g., crystal composition, compositional variability, accessory phases). Natural uraninite (nominally UO{sub 2+x}) which has undergone long-term corrosion can be studied to infer the long-term behavior of nuclear fuel. Previously, uraninite from the Nopal I deposit, Pena Blanca district, Chihuahua, Mexico, has been shown to constitute an outstanding analog material for comparison with nuclear fuel. Similarities between Nopal I uraninite and nuclear fuel have been shown to include bulk composition, general crystal structure, and total trace element content. Data presented here suggest that, as a bulk material, Nopal I uraninite compares favorably with irradiated nuclear fuel. Nevertheless, some fine-scale differences are noted between Nopal I uraninite and irradiated nuclear fuel with respect to both internal structures and compositions. These observations suggest that whereas the long-term responses of the two materials to oxidative alteration in a geologic repository may be similar, the detailed mechanisms of initial oxidant penetration and the short-term oxidative alternation of Nopal I uraninite and irradiated nuclear fuel are likely to be different.

  12. The Nolans Bore rare-earth element-phosphorus-uranium mineral system: geology, origin and post-depositional modifications

    NASA Astrophysics Data System (ADS)

    Huston, David L.; Maas, Roland; Cross, Andrew; Hussey, Kelvin J.; Mernagh, Terrence P.; Fraser, Geoff; Champion, David C.

    2016-08-01

    Nolans Bore is a rare-earth element (REE)-U-P fluorapatite vein deposit hosted mostly by the ~1805 Ma Boothby Orthogneiss in the Aileron Province, Northern Territory, Australia. The fluorapatite veins are complex, with two stages: (1) massive to granular fluorapatite with inclusions of REE silicates, phosphates and (fluoro)carbonates, and (2) calcite-allanite with accessory REE-bearing phosphate and (fluoro)carbonate minerals that vein and brecciate the earlier stage. The veins are locally accompanied by narrow skarn-like (garnet-diopside-amphibole) wall rock alteration zones. SHRIMP Th-Pb analyses of allanite yielded an age of 1525 ± 18 Ma, interpreted as the minimum age of mineralisation. The maximum age is provided by a ~1550 Ma SHRIMP U-Pb age for a pegmatite that predates the fluorapatite veins. Other isotopic systems yielded ages from ~1443 to ~345 Ma, implying significant post-depositional isotopic disturbance. Calculation of initial ɛNd and 87Sr/86Sr at 1525 Ma and stable isotope data are consistent with an enriched mantle or lower crust source, although post-depositional disturbance is likely. Processes leading to formation of Nolans Bore began with north-dipping subduction along the south margin of the Aileron Province at 1820-1750 Ma, producing a metasomatised, volatile-rich, lithospheric mantle wedge. About 200 million years later, near the end of the Chewings Orogeny, this reservoir and/or the lower crust sourced alkaline low-degree partial melts which passed into the mid- and upper-crust. Fluids derived from these melts, which may have included phosphatic melts, eventually deposited the Nolans Bore fluorapatite veins due to fluid-rock interaction, cooling, depressurisation and/or fluid mixing. Owing to its size and high concentration of Th (2500 ppm), in situ radiogenic heating caused significant recrystallisation and isotopic resetting. The system finally cooled below 300 °C at ~370 Ma, possibly in response to unroofing during the Alice Springs

  13. OneGeology: Making the World’s Geological Map Data Accessible Online

    NASA Astrophysics Data System (ADS)

    Broome, H.; Jackson, I.; Robida, F.; Thorleifson, H.

    2009-12-01

    OneGeology (http://onegeology.org) is a successful international initiative of the geological surveys of the world and the flagship project of the ‘International Year of Planet Earth’. Its aim is to provide dynamic web access to geological map data covering the world, creating a focus for accessing geological information for everyone. Thanks to the enthusiasm and support of participating nations the initiative has progressed rapidly and geological surveys and the many users of their data are excited about this ground-breaking project. Currently 10 international geoscience organizations have endorsed the initiative and more than 109 countries have agreed to participate. OneGeology works with whatever digital format is available in each country. The target scale is 1:1 million, but the project is pragmatic and accepts a range of scales and the best available data. The initiative recognizes that different nations have differing abilities to participate and transfer of know-how to those who need it is a key aspect of the approach. A key contributor to the success of OneGeology has been its utilization of the latest new web technology and an emerging data exchange standard for geological map data called GeoSciML. GeoSciML (GeoScience Markup Language) is a schema written in GML (Geography Markup Language) for geological data. GeoSciML has the ability to represent both the geography (geometries e.g. polygons, lines and points) and geological attribution in a clear and structured format. OneGeology was launched March 2007 at the inaugural workshop in Brighton England. At that workshop the 43 participating nations developed a declaration of a common objective and principles called the “Brighton Accord” (http://onegeology.org/what_is/accord.html) . Work was initiated immediately and the resulting OneGeology Portal was launched at the International Geological Congress in Oslo in August 2008 by Simon Winchester, author of “The Map that Changed the World”. Since the

  14. 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)

    Ballew, G.

    1977-01-01

    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.

  15. Planetary Geologic Mapping Handbook - 2010. Appendix

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    Geologic maps present, in an historical context, fundamental syntheses of interpretations of the materials, landforms, structures, and processes that characterize planetary surfaces and shallow subsurfaces. Such maps also provide a contextual framework for summarizing and evaluating thematic research for a given region or body. In planetary exploration, for example, geologic maps are used for specialized investigations such as targeting regions of interest for data collection and for characterizing sites for landed missions. Whereas most modern terrestrial geologic maps are constructed from regional views provided by remote sensing data and supplemented in detail by field-based observations and measurements, planetary maps have been largely based on analyses of orbital photography. For planetary bodies in particular, geologic maps commonly represent a snapshot of a surface, because they are based on available information at a time when new data are still being acquired. Thus the field of planetary geologic mapping has been evolving rapidly to embrace the use of new data and modern technology and to accommodate the growing needs of planetary exploration. Planetary geologic maps have been published by the U.S. Geological Survey (USGS) since 1962. Over this time, numerous maps of several planetary bodies have been prepared at a variety of scales and projections using the best available image and topographic bases. Early geologic map bases commonly consisted of hand-mosaicked photographs or airbrushed shaded-relief views and geologic linework was manually drafted using mylar bases and ink drafting pens. Map publishing required a tedious process of scribing, color peel-coat preparation, typesetting, and photo-laboratory work. Beginning in the 1990s, inexpensive computing, display capability and user-friendly illustration software allowed maps to be drawn using digital tools rather than pen and ink, and mylar bases became obsolete. Terrestrial geologic maps published by

  16. Reports of planetary geology program, 1983

    NASA Technical Reports Server (NTRS)

    Holt, H. E. (Compiler)

    1984-01-01

    Several areas of the Planetary Geology Program were addressed including outer solar system satellites, asteroids, comets, Venus, cratering processes and landform development, volcanic processes, aeolian processes, fluvial processes, periglacial and permafrost processes, geomorphology, remote sensing, tectonics and stratigraphy, and mapping.

  17. Geomorphology in North American Geology Departments, 1971

    ERIC Educational Resources Information Center

    White, Sidney E.; Malcolm, Marshall D.

    1972-01-01

    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)

  18. Etymology of Some Common Geologic Terms

    ERIC Educational Resources Information Center

    Lutz, Alan

    1978-01-01

    A knowledge of Latin, Greek, and modern foreign language prefixes and suffixes often enables one to define a word without using a dictionary. A list of certain common geologic terms and their etymologies is provided. (Author/MA)

  19. The geology and geophysics of Mars

    NASA Technical Reports Server (NTRS)

    Saunders, R. S.

    1976-01-01

    The current state of knowledge concerning the regional geology and geophysics of Mars is summarized. Telescopic observations of the planet are reviewed, pre-Mariner models of its interior are discussed, and progress achieved with the Mariner flybys, especially that of Mariner 9, is noted. A map of the Martian geological provinces is presented to provide a summary of the surface geology and morphology. The contrast between the northern and southern hemispheres is pointed out, and the characteristic features of the surface are described in detail. The global topography of the planet is examined along with its gravitational field, gravity anomalies, and moment of inertia. The general sequence of events in Martian geological history is briefly outlined.

  20. Reports of planetary geology program, 1980. [Bibliography

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    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.

  1. The Geologic Story of Colorado National Monument

    USGS Publications Warehouse

    Lohman, Stanley William

    1981-01-01

    From 1946 until about 1956 I carried out fieldwork intermittently on the geology and artesian water supply of the Grand Junction area, Colorado, the results of which have been published. The area mapped geologically contains about 332 square miles in the west-central part of Mesa County and includes all of Colorado National Monument. During the field work several successive custodians or superintendents and several park naturalists urged that upon completion of my professional paper I prepare a brief account of the geology of the Monument in terms understandable by laymen, and which could be sold at the Visitor Center. This I was happy to do and there resulted 'The geologic story of Colorado National Monument', published by the Colorado and Black Canyon Natural History Association in cooperation with the National Park Service. This report contained colored sketches by John R. Stacy and a colored cover, but the photographs and many of the drawings were reproduced in black and white.

  2. Significant achievements in the planetary geology program

    NASA Technical Reports Server (NTRS)

    Head, J. W. (Editor)

    1984-01-01

    Recent developments in planetology research are summarized. Important developments are summarized in topics ranging from solar system evolution, comparative planetology, and geologic processes active on other planetary bodies, to techniques and instrument development for exploration.

  3. TRENDS IN ENGINEERING GEOLOGIC AND RELATED MAPPING.

    USGS Publications Warehouse

    Varnes, David J.; Keaton, Jeffrey R.

    1983-01-01

    Progress is reviewed that has been made during the period 1972-1982 in producing medium- and small-scale engineering geologic maps with a variety of content. Improved methods to obtain and present information are evolving. Standards concerning text and map content, soil and rock classification, and map symbols have been proposed. Application of geomorphological techniques in terrain evaluation has increased, as has the use of aerial photography and other remote sensing. Computers are being used to store, analyze, retrieve, and print both text and map information. Development of offshore resources, especially petroleum, has led to marked improvement and growth in marine engineering geology and geotechnology. Coordinated planning for societal needs has required broader scope and increased complexity of both engineering geologic and environmental geologic studies. Refs.

  4. Mineral Resources, Geological Structure and Landform Surveys

    NASA Technical Reports Server (NTRS)

    Short, M. N.

    1973-01-01

    Significant results are presented of ERTS-1 investigations of landform surveys, mineral resources, and geological structures. The report covers four areas: (1) mapping investigations; (2) dynamic surface processes and landforms; (3) structural elements; and (4) mineral deposits.

  5. Groups in Geological Education, Research, and Organizations

    ERIC Educational Resources Information Center

    Romey, William D.

    1974-01-01

    Discusses different methods of instruction, such as the Keller Plan, audio-visual-tutorial methods, contract systems, and group seminars. Also discusses the role of groups in professional associations, particularly the National Association of Geology Teachers. (MLH)

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

    NASA Astrophysics Data System (ADS)

    Asch, Kristine; Tellez-Arenas, Agnes

    2010-05-01

    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

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

    NASA Technical Reports Server (NTRS)

    Lyon, R. J. P.; Prelat, A. E.; Kirk, R. (Principal Investigator)

    1981-01-01

    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.

  8. Geologic investigations of outer planets satellites

    NASA Technical Reports Server (NTRS)

    Strom, R. G.

    1984-01-01

    Four tests are examined: (1) investigation of volcanism on Io; Interim results of thermal and structural modeling of volcanism on Io are presented, (2) a study of the ancient heavily cratered regions on Ganymede, (3) a geologic comparison of the cratering record on Ganymede and Callisto, and (4) a geological and chemical investigation of internal resurfacing processes on the Saturnian satellites. Tasks 2, 3, and 4 utilize Voyager imaging data.

  9. Impact cratering at geologic stage boundaries

    NASA Technical Reports Server (NTRS)

    Stothers, Richard B.

    1993-01-01

    The largest known Cenozoic impact craters with the most accurately measured ages are found to correlate very closely with geologic stage boundaries. The level of confidence in this result is 98-99 percent even under the most pessimistic assumptions concerning dating errors. One or more large impacts may have led, in at least some cases, to the extinctions and first appearances of biotic species that mark many of the geologic stage boundaries.

  10. Soil-plant-microbial relations in hydrothermally altered soils of Northern California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soils developed on relict hydrothermally altered soils throughout the Western United States present unique opportunities to study the role of geology on above and belowground biotic activity and composition. Soil and vegetation samples were taken at three unaltered andesite and three hydrothermally ...

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

    USGS Publications Warehouse

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

    2005-01-01

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

  12. Sphene-a geological chameleon

    SciTech Connect

    Jaffe, H.W. . Geology Dept.)

    1993-03-01

    Synthetic sphene, CaTiO(SiO[sub 4]), is colorless and the natural, rock-forming mineral, yellow-brown-red-black. Sphene is:(Ca, U, Th, Pb, REE)(Ti, Fe[sup 3+], Al, Nb, Cr) (O,F)(SiO[sub 4]). Color appears to change and deepen with geologic age and radiation dosage, based upon study of 100-200 samples concentrated from calc-alkaline and alkaline plutonic rocks. Maximum absorption of light coincides with Z, the slow vibration direction, and high index of refraction, n=1.943-2.110, along a zig-zag or kinked octahedral chain, made up of: O-Ti-O-Fe-O-Ti-O-Nb-O-Ti-O..., where each O is an octahedral corner, and each transition metal, M, and octahedral center. Octahedra in each chain are cross-linked by (SiO[sub 4]) tetrahedral corners, and Ca ions lie in 7-fold holes. Along a chain, O-Ti-O distances alternate between 1.973 and 1.766 [angstrom]. Short O-M distances favor O-M charge transfer and adsorption of UV, blue, and green light, yielding yellow transmission. Energetic U+Th alpha-particle recoil will induce lattice damage over time (t) where dosage =[alpha]t, or alpha/mg/t and may involve 10[sup 15] alpha events in a Precambrian mineral. High dosage promotes a metamict state with partial loss of crystallinity, strain, expansion, hydration, and partial reduction of Fe[sup 3+] [r arrow] Fe[sup 2+]. Yellow-brown sphene has become black over time. Grains and fragments of black, metamict Precambrian sphene from Ontario and S. Africa, placed between graphite electrodes and energized for 3 secs. at T=7800[degree] in a carbon arc, turned bright yellow on cooling, without having fused. Reoxidation of Fe[sup 2+] [r arrow] Fe[sup 3+] in the arc would induce lattice contraction as r[sub Fe[sup 3+

  13. Tethys - Geological and Spectral Properties

    NASA Astrophysics Data System (ADS)

    Stephan, Katrin; Jaumann, Ralf; Wagner, Roland; Clark, Roger N.; Cruikshank, Dale P.; Dalle Ore, Cristina; Brown, Robert H.; Giese, Bernd; Roatsch, Thomas; Matson, Dennis; Baines, Kevin H.; Filacchione, Gianrico; Capaccione, Fabrizio; Burratti, Bonnie J.; Nicholson, Phil D.; Rodriguez, Sebastian

    2015-04-01

    Despite the spectral dominance of H2O ice on Tethys' surface, distinct spectral variations derived by the Cassini VIMS instrument could be detected. The ice infrared absorption strengths are very different from what was expected from the visible albedo derived from Voyager and Cassini camera data. Although on Tethys, the major ice absorptions at 1.5 and 2µm are general stronger on the leading hemisphere of the satellite similar to that seen on the neighboring satellites Dione and Rhea, the detailed mapping shows a more complex pattern. Two relatively narrow N/S trending bands enriched in H2O ice of relatively large particle size separate the Saturn-facing and the anti-Saturnian hemisphere. The largest impact crater Odysseus (33°N/129°W) is included in the N/S trending band of deeper H2O absorptions on the leading hemisphere, whereas the geologically older and fourth largest impact crater Penelope (11°S/249°W) is excluded from the 'icy' band on the trailing hemisphere - supporting an exogenic origin of these bands. The oval shaped dark albedo unit observed by Voyager in the equatorial region of Tethys' leading hemisphere, which could be related to magnetospheric 'dust' impacting the surface, exhibits slightly surpressed H2O ice absorptions compared to their surrounding regions. Variations in the spectral slope from the visible to the ultra-violet wavelength range are similar to the variations observed by Cassini ISS. The spectral slope is steepest (i.e. the effect of an ultra-violet absorber other than H2O ice is strongest) on the leading as well on the trailing hemisphere. No spectral properties could be exclusively associated with Tethys' extended graben system Ithaca Chasma. Local variations, i.e. local deepening of H2O ice absorptions, are mostly related to several probably fresh impact craters and to locations where topographic slope is high like crater walls. However, only a few such fresh impact craters could be observed.

  14. Groundwater in geologic processes, 2nd edition

    USGS Publications Warehouse

    Ingebritsen, Steven E.; Sanford, Ward E.; Neuzil, Christopher E.

    2006-01-01

    Interest in the role of Groundwater in Geologic Processes has increased steadily over the past few decades. Hydrogeologists and geologists are now actively exploring the role of groundwater and other subsurface fluids in such fundamental geologic processes as crustal heat transfer, ore deposition, hydrocarbon migration, earthquakes, tectonic deformation, diagenesis, and metamorphism.Groundwater in Geologic Processes is the first comprehensive treatment of this body of inquiry. Chapters 1 to 4 develop the basic theories of groundwater motion, hydromechanics, solute transport, and heat transport. Chapter 5 applies these theories to regional groundwater flow systems in a generic sense, and Chapters 6 to 13 focus on particular geologic processes and environments. Relative to the first edition of Groundwater in Geologic Processes , this second edition includes a much more comprehensive treatment of hydromechanics (the coupling of groundwater flow and deformation). It also includes new chapters on "compaction and diagenesis," "metamorphism," and "subsea hydrogeology." Finally, it takes advantage of the substantial body of published research that has appeared since the first edition in 1998. The systematic presentation of theory and application, and the problem sets that conclude each chapter, make this book ideal for undergraduate- and graduate-level geology courses (assuming that the students have some background in calculus and introductory chemistry). It also serves as an invaluable reference for researchers and other professionals in the field

  15. Geology of the Huntsville quadrangle, Alabama

    USGS Publications Warehouse

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

    1961-01-01

    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.

  16. Geologic mapping can boost productivity, safety underground

    SciTech Connect

    Ledvina, C.T.

    1986-04-01

    Geologic mapping in hardrock mines is old hat, but in the coal industry it's a relatively new management tool, Only during the past eight to 10 years have some of the larger coal operators been convinced that mapping of macro- and micro-structures in their mines may help to make the mines more productive, more profitable and more safe. In most underground coal mines, roof conditions-indeed, mining conditions in general-are dependent upon geologic factors. Of special significance are the roof falls, almost always a function of roof geology. Unfortunately, many important geologic factors that may provide clues to areas prone to roof falls are frequently too small or too local to be detected by drilling programs and go undected until mining reveals them. By applying basic techniques of geologic mapping, using simple tools and little time, many important relationships between geologic factors and actual roof and mining conditions can be more easily understood. And by understanding these relationships, mining and roof control plans can be adjusted to accommodate or avoid poor conditions, often in advance of mining. Mapping thus benefits not only operating mines but supplements exploration or pre-mining investigation.

  17. Metamorphic geology: Why should we care?

    NASA Astrophysics Data System (ADS)

    Tajcmanova, Lucie; Moulas, Evangelos; Vrijmoed, Johannes

    2016-04-01

    Estimation of pressure-temperature (P-T) from petrographic observations in metamorphic rocks has become a common practice in petrology studies during the last 50 years. This data then often serves as a key input in geodynamic reconstructions and thus directly influences our understanding of lithospheric processes. Such an approach might have led the metamorphic geology field to a certain level of quiescence. Obtaining high-quality analytical data from metamorphic rocks has become a standard part of geology studies. The numerical tools for geodynamic reconstructions have evolved to a great extend as well. Furthermore, the increasing demand on using the Earth's interior for sustainable energy or nuclear waste disposal requires a better understanding of the physical processes involved in fluid-rock interaction. However, nowadays, metamorphic data have apparently lost their importance in the "bigger picture" of the Earth sciences. Interestingly, the suppression of the metamorphic geology discipline limits the potential for understanding the aforementioned physical processes that could have been exploited. In fact, those phenomena must be considered in the development of new generations of fully coupled numerical codes that involve reacting materials with changing porosity while obeying conservation of mass, momentum and energy. In our contribution, we would like to discuss the current role of metamorphic geology. We will bring food for thoughts and specifically touch upon the following questions: How can we revitalize metamorphic geology? How can we increase the importance of it? How can metamorphic geology contribute to societal issues?

  18. Geology in the Vicinity of the TYBO and BENHAM Underground Nuclear Tests, Pahute Mesa, Nevada Test Site

    SciTech Connect

    L. B. Prothro

    2001-12-01

    Recent radiochemical evidence from groundwater characterization and monitoring wells in the vicinity of the TYBO and BENHAM underground nuclear tests in Area 20 of the Nevada Test Site, suggests that migration of radionuclides within groundwater beneath this portion of Area 20 may be more rapid than previously thought. In order to gain a better understanding of the hydrogeologic conditions in the TYBO-BENHAM area for more accurate flow and transport modeling, a reevaluation of the subsurface geologic environment in the vicinity of the two underground tests was conducted. Eight existing drill holes provided subsurface control for the area. These holes included groundwater characterization and monitoring wells, exploratory holes, and large-diameter emplacement holes used for underground nuclear weapons tests. Detailed and consistent geologic descriptions of these holes were produced by updating existing geologic descriptions with data from petrographic, chemical, and mineralogic analyses, and current stratigraphic concepts of the region. The updated descriptions, along with surface geologic data, were used to develop a detailed geologic model of the TYBO-BENHAM area. This model is represented by diagrams that correlate stratigraphic, lithologic, and alteration intervals between holes, and by isopach and structure maps and geologic cross sections. Regional data outside the TYBO-BENHAM area were included in the isopach and structure maps to better evaluate the geology of the TYBO-BENHAM area in a regional context. The geologic model was then evaluated with regard to groundwater flow and radionuclide migration to assess the model's implications for flow and transport modeling. Implications include: (1) confirmation of the general hydrogeology of the area described in previous studies; (2) the presence of two previously unrecognized buried faults that could act as zones of enhanced permeability within aquifers; and (3) secondary alteration within tuff confining units

  19. OneGeology-Europe Plus Initiative

    NASA Astrophysics Data System (ADS)

    Capova, Dana; Kondrova, Lucie

    2014-05-01

    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

  20. The geologic mapping of asteroid Vesta

    NASA Astrophysics Data System (ADS)

    Williams, D.; Yingst, A.; Garry, B.

    2014-07-01

    As part of NASA's Dawn mission [1,2] we conducted a geologic mapping campaign to provide a systematic, cartography-based initial characterization of the global and regional geology of asteroid Vesta. The goal of geological maps is to place observations of surface features into their stratigraphic context to develop a geologic history of the evolution of planetary surfaces. Geologic mapping reduces the complexity of heterogeneous planetary surfaces into comprehensible portions, defining and characterizing discrete material units based upon physical attributes related to the geologic processes that produced them, and enabling identification of the relative roles of various processes (impact cratering, tectonism, volcanism, erosion and deposition) in shaping planetary surfaces [3,4]. The Dawn Science Team produced cartographic products of Vesta from the Framing Camera images, including global mosaics as well as 15 regional quadrangles [5], which served as bases for the mapping. We oversaw the geologic mapping campaign during the Nominal Mission, including production of a global geologic map at scale 1:500,000 using images from the High Altitude Mapping Orbit [6] and 15 quadrangle geologic maps at scale 1:250,000 using images from the Low Altitude Mapping Orbit [7]. The goal was to support the Dawn Team by providing geologic and stratigraphic context of surface features and supporting the analysis of data from the Visible and Infrared Spectrometer (VIR) and the Gamma Ray and Neutron Detector (GRaND). Mapping was done using ArcGIS™ software, in which quadrangle mapping built on interpretations derived from the global geologic map but were updated and modified to take advantage of the highest spatial resolution data. Despite challenges (e.g., Vesta's highly sloped surface [8] deforms impact craters and produces mass movements that buries contacts), we were successfully able to map the whole surface of Vesta and identify a geologic history as represented in our maps and

  1. Introductory Geology From the Liberal Arts Approach: A Geology-Sociology Linked Course

    NASA Astrophysics Data System (ADS)

    Walsh, E. O.; Davis, E.

    2008-12-01

    Geology can be a hard sell to college students, especially to college students attending small, liberal arts institutions in localities that lack exaggerated topography. At these schools, Geology departments that wish to grow must work diligently to attract students to the major; professors must be able to convince a wider audience of students that geology is relevant to their everyday lives. Toward this end, a Physical Geology course was linked with an introductory Sociology course through the common theme of Consumption. The same students took the two courses in sequence, beginning with the Sociology course and ending with Physical Geology; thus, students began by discussing the role of consumption in society and ended by learning about the geological processes and implications of consumption. Students were able to ascertain the importance of geology in their daily lives by connecting Earth processes to specific products they consume, such as cell phones and bottled water. Students were also able to see the connection between seemingly disparate fields of study, which is a major goal of the liberal arts. As a theme, Consumption worked well to grab the attention of students interested in diverse issues, such as environmental science or social justice. A one-hour lecture illustrating the link between sociology and geology was developed for presentation to incoming freshmen and their parents to advertise the course. Initial response has been positive, showing an increase in awareness of geological processes among students with a wide range of interests.

  2. OneGeology-Europe: architecture, portal and web services to provide a European geological map

    NASA Astrophysics Data System (ADS)

    Tellez-Arenas, Agnès.; Serrano, Jean-Jacques; Tertre, François; Laxton, John

    2010-05-01

    OneGeology-Europe is a large ambitious project to make geological spatial data further known and accessible. The OneGeology-Europe project develops an integrated system of data to create and make accessible for the first time through the internet the geological map of the whole of Europe. The architecture implemented by the project is web services oriented, based on the OGC standards: the geological map is not a centralized database but is composed by several web services, each of them hosted by a European country involved in the project. Since geological data are elaborated differently from country to country, they are difficult to share. OneGeology-Europe, while providing more detailed and complete information, will foster even beyond the geological community an easier exchange of data within Europe and globally. This implies an important work regarding the harmonization of the data, both model and the content. OneGeology-Europe is characterised by the high technological capacity of the EU Member States, and has the final goal to achieve the harmonisation of European geological survey data according to common standards. As a direct consequence Europe will make a further step in terms of innovation and information dissemination, continuing to play a world leading role in the development of geosciences information. The scope of the common harmonized data model was defined primarily by the requirements of the geological map of Europe, but in addition users were consulted and the requirements of both INSPIRE and ‘high-resolution' geological maps were considered. The data model is based on GeoSciML, developed since 2006 by a group of Geological Surveys. The data providers involved in the project implemented a new component that allows the web services to deliver the geological map expressed into GeoSciML. In order to capture the information describing the geological units of the map of Europe the scope of the data model needs to include lithology; age; genesis and

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

    NASA Astrophysics Data System (ADS)

    Murphy, W. M.

    2009-12-01

    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

  4. Sedimentary reservoir oxidation during geologic CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Lammers, Laura N.; Brown, Gordon E.; Bird, Dennis K.; Thomas, Randal B.; Johnson, Natalie C.; Rosenbauer, Robert J.; Maher, Katharine

    2015-04-01

    Injection of carbon dioxide into subsurface geologic reservoirs during geologic carbon sequestration (GCS) introduces an oxidizing supercritical CO2 phase into a subsurface geologic environment that is typically reducing. The resulting redox disequilibrium provides the chemical potential for the reduction of CO2 to lower free energy organic species. However, redox reactions involving carbon typically require the presence of a catalyst. Iron oxide minerals, including magnetite, are known to catalyze oxidation and reduction reactions of C-bearing species. If the redox conditions in the reservoir are modified by redox transformations involving CO2, such changes could also affect mineral stability, leading to dissolution and precipitation reactions and alteration of the long-term fate of CO2 in GCS reservoirs. We present experimental evidence that reservoirs with reducing redox conditions are favorable environments for the relatively rapid abiotic reduction of CO2 to organic molecules. In these experiments, an aqueous suspension of magnetite nanoparticles was reacted with supercritical CO2 under pressure and temperature conditions relevant to GCS in sedimentary reservoirs (95-210 °C and ∼100 bars of CO2). Hydrogen production was observed in several experiments, likely caused by Fe(II) oxidation either at the surface of magnetite or in the aqueous phase. Heating of the Fe(II)-rich system resulted in elevated PH2 and conditions favorable for the reduction of CO2 to acetic acid. Implications of these results for the long-term fate of CO2 in field-scale systems were explored using reaction path modeling of CO2 injection into reservoirs containing Fe(II)-bearing primary silicate minerals, with kinetic parameters for CO2 reduction obtained experimentally. The results of these calculations suggest that the reaction of CO2 with reservoir constituents will occur in two primary stages (1) equilibration of CO2 with organic acids resulting in mineral-fluid disequilibrium, and

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

    USGS Publications Warehouse

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

    2003-01-01

    . 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

  6. The Black Mountain tectonic zone--a reactivated northeast-trending crustal shear zone in the Yukon-Tanana Upland of east-central Alaska: Chapter D in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

    USGS Publications Warehouse

    O'Neill, J. Michael; Day, Warren C.; Alienikoff, John N.; Saltus, Richard W.; Gough, Larry P.; Day, Warren C.

    2007-01-01

    The Black Mountain tectonic zone in the YukonTanana terrane of east-central Alaska is a belt of diverse northeast-trending geologic features that can been traced across Black Mountain in the southeast corner of the Big Delta 1°×3° degree quadrangle. Geologic mapping in the larger scale B1 quadrangle of the Big Delta quadrangle, in which Black Mountain is the principal physiographic feature, has revealed a continuous zone of normal and left-lateral strikeslip high-angle faults and shear zones, some of which have late Tertiary to Quaternary displacement histories. The tectonic zone includes complexly intruded wall rocks and intermingled apophyses of the contiguous mid-Cretaceous Goodpaster and Mount Harper granodioritic plutons, mafic to intermediate composite dike swarms, precious metal mineralization, early Tertiary volcanic activity and Quaternary fault scarps. These structures define a zone as much as 6 to 13 kilometers (km) wide and more than 40 km long that can be traced diagonally across the B1 quadrangle into the adjacent Eagle 1°×3° quadrangle to the east. Recurrent activity along the tectonic zone, from at least mid-Cretaceous to Quaternary, suggests the presence of a buried, fundamental tectonic feature beneath the zone that has influenced the tectonic development of this part of the Yukon-Tanana terrane. The tectonic zone, centered on Black Mountain, lies directly above a profound northeast-trending aeromagnetic anomaly between the Denali and Tintina fault systems. The anomaly separates moderate to strongly magnetic terrane on the northwest from a huge, weakly magnetic terrane on the southeast. The tectonic zone is parallel to the similarly oriented left-lateral, strike-slip Shaw Creek fault zone 85 km to the west.

  7. Volcanic and geologic database projects of the Geological Survey of Japan (Invited)

    NASA Astrophysics Data System (ADS)

    Takarada, S.; Nakano, S.; Hoshizumi, H.; Itoh, J.; Urai, M.; Nishiki, K.

    2009-12-01

    Geological Survey of Japan (GSJ) is presently implementing the GEO-DB project, which aims to integrate all kinds of geological information in GSJ. GSJ published more than 50 CD-ROM series and established more than 20 databases at the Research Information Database (RIO-DB) of the National Institute of Advanced Industrial Science and Technology (AIST). Presently, four volcanic databases are open to the public: (1) Quaternary volcano database (RIO-DB), (2) Active volcano database (RIO-DB), and (3) ASTER satellite image database of major volcanoes. The Quaternary volcano database contains information such as volcanic type, history, age and pictures of more than 300 Quaternary volcanoes in Japan. More detailed volcanic information will be added to the database in the near future. The active volcano database contains information of active volcanoes in Japan such as the catalog of eruptive events during the last 10,000 years and geological maps of active volcanoes. The ASTER satellite image database provides sequential ASTER satellite image datasets of major volcanoes in the world. Collaboration between Quaternary and active volcano databases and the VOGRIPA project is the next important activity at the Geological Survey of Japan. The Geological Survey of Japan introduced the Integrated Geological Map Database (GeoMapDB) in 2006. The GeoMapDB is based on a WebGIS technology, which makes it possible to browse, overlay and search geological maps online. The database contains geological maps with scales ranging from 1:2 million to 1:25,000. Links to aforementioned volcanic database and active fault database in RIO-DB are also available. OneGeology is an international initiative of the geological surveys of the world and a flagship project of the ‘International Year of Planet Earth’. It aims to create dynamic geological map of the world available at the world wide web. Geological Surveys from 109 countries of the world are participating in this project. The Geological

  8. Remote sensing and geologic studies of localized dark mantle deposits on the moon

    NASA Technical Reports Server (NTRS)

    Hawke, B. R.; Coombs, C. R.; Lucey, P. G.; Owensby, P. D.; Gaddis, L. R.

    1989-01-01

    Localized lunar dark mantle deposits (LDMD) are small, smooth low-albedo units of pyroclastic origin commonly found associated with endogenic source craters. Analysis of near-infrared spectra, multispectral images, and radar data obtained for 25 LDMD has led to the identification of three compositional groups of LDMD. Group 1 deposits are composed predominantly of highlands-rich wall rock but also contain a substantial juvenile component, Group 2 deposits are composed largely of mare plug rock material, while Group 3 deposits are rich in a mixture of olivine and pyroxene. Variations in eruption conditions are interpreted to be largely responsible for the varying mineralogy of these three types of deposits.

  9. Altered fingerprints: analysis and detection.

    PubMed

    Yoon, Soweon; Feng, Jianjiang; Jain, Anil K

    2012-03-01

    The widespread deployment of Automated Fingerprint Identification Systems (AFIS) in law enforcement and border control applications has heightened the need for ensuring that these systems are not compromised. While several issues related to fingerprint system security have been investigated, including the use of fake fingerprints for masquerading identity, the problem of fingerprint alteration or obfuscation has received very little attention. Fingerprint obfuscation refers to the deliberate alteration of the fingerprint pattern by an individual for the purpose of masking his identity. Several cases of fingerprint obfuscation have been reported in the press. Fingerprint image quality assessment software (e.g., NFIQ) cannot always detect altered fingerprints since the implicit image quality due to alteration may not change significantly. The main contributions of this paper are: 1) compiling case studies of incidents where individuals were found to have altered their fingerprints for circumventing AFIS, 2) investigating the impact of fingerprint alteration on the accuracy of a commercial fingerprint matcher, 3) classifying the alterations into three major categories and suggesting possible countermeasures, 4) developing a technique to automatically detect altered fingerprints based on analyzing orientation field and minutiae distribution, and 5) evaluating the proposed technique and the NFIQ algorithm on a large database of altered fingerprints provided by a law enforcement agency. Experimental results show the feasibility of the proposed approach in detecting altered fingerprints and highlight the need to further pursue this problem.

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

    USGS Publications Warehouse

    Wells, Ray

    2006-01-01

    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.

  11. Interplay between microorganisms and geochemistry in geological carbon storage

    SciTech Connect

    Altman, Susan J.; Kirk, Matthew Fletcher; Santillan, Eugenio-Felipe U.; Bennett, Philip C.

    2016-02-28

    Researchers at the Center for Frontiers of Subsurface Energy Security (CFSES) have conducted laboratory and modeling studies to better understand the interplay between microorganisms and geochemistry for geological carbon storage (GCS). We provide evidence of microorganisms adapting to high pressure CO2 conditions and identify factors that may influence survival of cells to CO2 stress. Factors that influenced the ability of cells to survive exposure to high-pressure CO2 in our experiments include mineralogy, the permeability of cell walls and/or membranes, intracellular buffering capacity, and whether cells live planktonically or within biofilm. Column experiments show that, following exposure to acidic water, biomass can remain intact in porous media and continue to alter hydraulic conductivity. Our research also shows that geochemical changes triggered by CO2 injection can alter energy available to populations of subsurface anaerobes and that microbial feedbacks on this effect can influence carbon storage. Our research documents the impact of CO2 on microorganisms and in turn, how subsurface microorganisms can influence GCS. Furthermore, we conclude that microbial presence and activities can have important implications for carbon storage and that microorganisms should not be overlooked in further GCS research.

  12. Interplay between microorganisms and geochemistry in geological carbon storage

    DOE PAGES

    Altman, Susan J.; Kirk, Matthew Fletcher; Santillan, Eugenio-Felipe U.; ...

    2016-02-28

    Researchers at the Center for Frontiers of Subsurface Energy Security (CFSES) have conducted laboratory and modeling studies to better understand the interplay between microorganisms and geochemistry for geological carbon storage (GCS). We provide evidence of microorganisms adapting to high pressure CO2 conditions and identify factors that may influence survival of cells to CO2 stress. Factors that influenced the ability of cells to survive exposure to high-pressure CO2 in our experiments include mineralogy, the permeability of cell walls and/or membranes, intracellular buffering capacity, and whether cells live planktonically or within biofilm. Column experiments show that, following exposure to acidic water, biomassmore » can remain intact in porous media and continue to alter hydraulic conductivity. Our research also shows that geochemical changes triggered by CO2 injection can alter energy available to populations of subsurface anaerobes and that microbial feedbacks on this effect can influence carbon storage. Our research documents the impact of CO2 on microorganisms and in turn, how subsurface microorganisms can influence GCS. Furthermore, we conclude that microbial presence and activities can have important implications for carbon storage and that microorganisms should not be overlooked in further GCS research.« less

  13. Multistage hydrothermal silicification and Fe-Tl-As-Sb-Ge-REE enrichment in the Red Dog Zn-Pb-Ag district, northern Alaska: Geochemistry, origin, and exploration applications

    USGS Publications Warehouse

    Slack, J.F.; Kelley, K.D.; Anderson, V.M.; Clark, J.L.; Ayuso, R.A.

    2004-01-01

    filling of fractures that developed in previously lithified rock. Uniformly low Ca and Mg and uniformly negative Ce anomalies in highly siliceous Red Dog wall rocks reflect hydrothermal decarbonation reactions and pervasive silicification owing to conductive cooling of oxidized metalliferous fluids. Similar Ca and Mg depletions are evident at Anarraaq but generally lack associated silicification, possibly because temperatures of the hydrothermal fluids were too low (<180??C) or because the thermal contrast between the fluids and wall rocks was smaller owing to the greater depth of alteration and mineralization there, compared with Red Dog. Chalcophile element anomalies (Fe, Zn, Pb, Tl, As, Sb) in wall rocks at both Red Dog and Anarraq are attributed to sulfidation reactions, coeval with subsurface Zn-Pb-Ag mineralization, during the mixing of oxidized metalliferous fluids with H2S-rich fluids derived locally within the Kuna Formation. Sedimentary wall rocks in the Red Dog district are characterized by a distinctive suite of geochemical anomalies, especially for Zn, Pb, Tl, As, Sb, Ge, and Eu/Eu*. At the Aqqaluk deposit, wall rocks without visible sphalerite or galena (<300 ppm Zn + Pb) have anomalous Eu/Eu*, Tl, Sb, and As for up to ???100 m stratigraphically below Zn-rich silica rock. At Anarraaq, the Tl anomaly is most extensively developed, and enrichment relative to unaltered black shale of the Kuna Formation is present up to 62 m above the highest Zn-Pb sulfide zones. The magnitude of the enrichment and systematic behavior of Tl in the district make Tl a promising geochemical exploration guide for Red Dog-type Zn-Pb-Ag deposits elsewhere. ?? 2004 by Economic Geology.

  14. The United States Geological Survey in Alaska; accomplishments during 1976

    USGS Publications Warehouse

    Blean, Kathleen M.

    1977-01-01

    United States Geological Survey projects in Alaska include a wide range of topics of economic and scientific interest. Studies in 1976 include economic geology, regional geology, stratigraphy, environmental geology, engineering geology, hydrology, and marine geology. Discussions of the findings or, in some instances, narratives of the course of the investigations are grouped in eight subdivisions corresponding to the six major onshore geographic regions, the offshore projects, and projects that are statewide in scope. Locations of the study areas are shown. In addition, many reports and maps covering various aspects of the geology and mineral and water resources of the State were published. These publications are listed. (Woodard-USGS)

  15. Geology Before Pluto: Pre-encounter Considerations

    NASA Astrophysics Data System (ADS)

    Moore, Jeffrey

    2014-05-01

    Jeffrey M. Moore (NASA Ames) and the New Horizons Science Team Pluto, its large satellite Charon, and its four small known satellites represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique, lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Modeling of the interior suggests that geologic activity may have been significant to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. However, these putative indicators of Pluto's geologic history are inconclusive and unspecific. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observation. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system's geologic history. The cameras of New Horizons will provide robust data sets that should be immanently amenable to geological analysis of the Pluto System's landscapes. In this talk, we begin with a brief discussion of the planned observations by the New Horizons cameras that will bear most directly on geological interpretability. Then I will broadly review major geological processes that could potentially operate on the surfaces of Pluto and its moons. I will first survey exogenic processes (i.e. those for which energy for surface modification is supplied externally to the planetary surface): impact cratering, sedimentary processes (including volatile migration), and the

  16. Geologic and Mineral Resource Map of Afghanistan

    USGS Publications Warehouse

    Doebrich, Jeff L.; Wahl, Ronald R.; With Contributions by Ludington, Stephen D.; Chirico, Peter G.; Wandrey, Craig J.; Bohannon, Robert G.; Orris, Greta J.; Bliss, James D.; Wasy, Abdul; Younusi, Mohammad O.

    2006-01-01

    Data Summary The geologic and mineral resource information shown on this map is derived from digitization of the original data from Abdullah and Chmyriov (1977) and Abdullah and others (1977). The U.S. Geological Survey (USGS) has made no attempt to modify original geologic map-unit boundaries and faults as presented in Abdullah and Chmyriov (1977); however, modifications to map-unit symbology, and minor modifications to map-unit descriptions, have been made to clarify lithostratigraphy and to modernize terminology. Labeling of map units has not been attempted where they are small or narrow, in order to maintain legibility and to preserve the map's utility in illustrating regional geologic and structural relations. Users are encouraged to refer to the series of USGS/AGS (Afghan Geological Survey) 1:250,000-scale geologic quadrangle maps of Afghanistan that are being released concurrently as open-file reports. The classification of mineral deposit types is based on the authors' interpretation of existing descriptive information (Abdullah and others, 1977; Bowersox and Chamberlin, 1995; Orris and Bliss, 2002) and on limited field investigations by the authors. Deposit-type nomenclature used for nonfuel minerals is modified from published USGS deposit-model classifications, as compiled in Stoeser and Heran (2000). New petroleum localities are based on research of archival data by the authors. The shaded-relief base is derived from Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) data having 85-meter resolution. Gaps in the original SRTM DEM dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). The marginal extent of geologic units corresponds to the position of the international boundary as defined by Abdullah and Chmyriov (1977), and the international boundary as shown on this map was acquired from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af) in

  17. Prototype of Partial Cutting Tool of Geological Map Images Distributed by Geological Web Map Service

    NASA Astrophysics Data System (ADS)

    Nonogaki, S.; Nemoto, T.

    2014-12-01

    Geological maps and topographical maps play an important role in disaster assessment, resource management, and environmental preservation. These map information have been distributed in accordance with Web services standards such as Web Map Service (WMS) and Web Map Tile Service (WMTS) recently. In this study, a partial cutting tool of geological map images distributed by geological WMTS was implemented with Free and Open Source Software. The tool mainly consists of two functions: display function and cutting function. The former function was implemented using OpenLayers. The latter function was implemented using Geospatial Data Abstraction Library (GDAL). All other small functions were implemented by PHP and Python. As a result, this tool allows not only displaying WMTS layer on web browser but also generating a geological map image of intended area and zoom level. At this moment, available WTMS layers are limited to the ones distributed by WMTS for the Seamless Digital Geological Map of Japan. The geological map image can be saved as GeoTIFF format and WebGL format. GeoTIFF is one of the georeferenced raster formats that is available in many kinds of Geographical Information System. WebGL is useful for confirming a relationship between geology and geography in 3D. In conclusion, the partial cutting tool developed in this study would contribute to create better conditions for promoting utilization of geological information. Future work is to increase the number of available WMTS layers and the types of output file format.

  18. Geological maps of the European seas - the EMODNET-Geology project.

    NASA Astrophysics Data System (ADS)

    Stevenson, Alan

    2014-05-01

    To support its objectives to achieve Good Environmental Status in Europe's seas by 2020, the European Commission established the European Marine Observation and Data Network (EMODNET) to assemble existing but fragmented and inaccessible marine data and to create interoperable, contiguous and publicly available information layers which encompass whole marine basins. EMODNET is a network of existing and developing European observation systems linked by a data management structure covering all European coastal waters, shelf seas and surrounding ocean basins. The marine departments of the European Geological Surveys form the basis of a partnership that implements the EMODNET-Geology project, part of a suite of EMODNET studies that also cover bathymetry, marine chemistry, marine biology, seabed habitats, physics and human activities in the marine environment. The EMODnet-Geology project will deliver integrated geological map products through the One Geology-Europe portal. EMODNET-Geology will have a distributed map service with each of the work packages delivering a specified layer that include seafloor geology, seabed sediments, mineral resources and geological events such as submarine slides and earthquakes. Further information about the EMODNET project can be found at: http://www.emodnet.eu/

  19. GDA (Geologic Data Assistant), an ArcPad extension for geologic mapping: code, prerequisites, and instructions

    USGS Publications Warehouse

    ,

    2006-01-01

    GDA (Geologic Data Assistant) is an extension to ArcPad, a mobile mapping software program by Environmental Systems Research Institute (ESRI) designed to run on personal digital assistant (PDA) computers. GDA and ArcPad allow a PDA to replace the paper notebook and field map traditionally used for geologic mapping. GDA allows easy collection of field data.

  20. Remote geologic structural analysis of Yucca Flat

    NASA Astrophysics Data System (ADS)

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

    1991-12-01

    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 digital elevation model (DEM), fits three-dimensional vectors to valley bottoms, and catalogs all potential fracture or fault planes defined by coplanar pairs of valley vectors. The system generates a cluster hierarchy of planar features having greater-than-random density that may represent areas of anomalous topography manifesting structural control of erosional drainage development. Because RGA uses computer methods to identify zones of hypothesized control of topography, ground truth using a well-characterized test site was critical in our evaluation of RGA's characterization of inaccessible test sites for seismic verification studies. Therefore, we applied RGA to a study area centered on Yucca Flat at the Nevada Test Site (NTS) and compared our results with both mapped geology and geologic structures and with seismic yield-magnitude models. This is the final report of PNL's RGA development project for peer review within the U.S. Department of Energy Office of Arms Control (OAC) seismic-verification community. In this report, we discuss the Yucca Flat study area, the analytical basis of the RGA system and its application to Yucca Flat, the results of the analysis, and the relation of the analytical results to known topography, geology, and geologic structures.

  1. Wave Propagation in Jointed Geologic Media

    SciTech Connect

    Antoun, T

    2009-12-17

    Predictive modeling capabilities for wave propagation in a jointed geologic media remain a modern day scientific frontier. In part this is due to a lack of comprehensive understanding of the complex physical processes associated with the transient response of geologic material, and in part it is due to numerical challenges that prohibit accurate representation of the heterogeneities that influence the material response. Constitutive models whose properties are determined from laboratory experiments on intact samples have been shown to over-predict the free field environment in large scale field experiments. Current methodologies for deriving in situ properties from laboratory measured properties are based on empirical equations derived for static geomechanical applications involving loads of lower intensity and much longer durations than those encountered in applications of interest involving wave propagation. These methodologies are not validated for dynamic applications, and they do not account for anisotropic behavior stemming from direcitonal effects associated with the orientation of joint sets in realistic geologies. Recent advances in modeling capabilities coupled with modern high performance computing platforms enable physics-based simulations of jointed geologic media with unprecedented details, offering a prospect for significant advances in the state of the art. This report provides a brief overview of these modern computational approaches, discusses their advantages and limitations, and attempts to formulate an integrated framework leading to the development of predictive modeling capabilities for wave propagation in jointed and fractured geologic materials.

  2. Remote geologic structural analysis of Yucca Flat

    SciTech Connect

    Foley, M.G.; Heasler, P.G.; Hoover, K.A. ); Rynes, N.J. ); Thiessen, R.L.; Alfaro, J.L. )

    1991-12-01

    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 digital elevation model (DEM), fits three-dimensional vectors to valley bottoms, and catalogs all potential fracture or fault planes defined by coplanar pairs of valley vectors. The system generates a cluster hierarchy of planar features having greater-than-random density that may represent areas of anomalous topography manifesting structural control of erosional drainage development. Because RGA uses computer methods to identify zones of hypothesized control of topography, ground truth using a well-characterized test site was critical in our evaluation of RGA's characterization of inaccessible test sites for seismic verification studies. Therefore, we applied RGA to a study area centered on Yucca Flat at the Nevada Test Site (NTS) and compared our results with both mapped geology and geologic structures and with seismic yield-magnitude models. This is the final report of PNL's RGA development project for peer review within the US Department of Energy Office of Arms Control (OAC) seismic-verification community. In this report, we discuss the Yucca Flat study area, the analytical basis of the RGA system and its application to Yucca Flat, the results of the analysis, and the relation of the analytical results to known topography, geology, and geologic structures. 41 refs., 39 figs., 2 tabs.

  3. Remote geologic structural analysis of Yucca Flat

    SciTech Connect

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

    1991-12-01

    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 digital elevation model (DEM), fits three-dimensional vectors to valley bottoms, and catalogs all potential fracture or fault planes defined by coplanar pairs of valley vectors. The system generates a cluster hierarchy of planar features having greater-than-random density that may represent areas of anomalous topography manifesting structural control of erosional drainage development. Because RGA uses computer methods to identify zones of hypothesized control of topography, ground truth using a well-characterized test site was critical in our evaluation of RGA`s characterization of inaccessible test sites for seismic verification studies. Therefore, we applied RGA to a study area centered on Yucca Flat at the Nevada Test Site (NTS) and compared our results with both mapped geology and geologic structures and with seismic yield-magnitude models. This is the final report of PNL`s RGA development project for peer review within the US Department of Energy Office of Arms Control (OAC) seismic-verification community. In this report, we discuss the Yucca Flat study area, the analytical basis of the RGA system and its application to Yucca Flat, the results of the analysis, and the relation of the analytical results to known topography, geology, and geologic structures. 41 refs., 39 figs., 2 tabs.

  4. Geological assessment of the greenhouse effect

    SciTech Connect

    Crowley, T.J. )

    1993-12-01

    Geologic studies provide a valuable perspective on the importance of greenhouse forcing for climate change. On both Pleistocene and tectonic time scales, changes in climate are positively correlated with greenhouse gas variations. However, the sensitivity of the system to greenhouse gas changes cannot yet be constrained by paleoclimate data below its present large range. Geologic records do not support one of the major predictions of greenhouse models-namely, that tropical sea surface temperatures will increase. Geologic data also suggest that winter cooling in high-latitude land areas is less than predicted by models. As the above-mentioned predictions appear to be systemic features of the present generation of climate models, some significant changes in model design may be required to reconcile models and geologic data. However, full acceptance of this conclusion requires more measurements and more systematic compilations of existing geologic data. Since progress in data collection in this area has been quite slow, uncertainties associated with these conclusions may persist for some time. 106 refs., 6 figs.

  5. Getting Geology Students Into the Field

    NASA Astrophysics Data System (ADS)

    Nocerino, J.

    2011-12-01

    The importance of field schools to practicing geologists is unquestionable; yet, the opportunities to experience field geology are dwindling. The Geological Society of America (GSA), in cooperation with ExxonMobil, are currently offering three programs to support and encourage field geology. The GSA/ExxonMobil Bighorn Basin Field award is a field seminar in the Bighorn Basin of north-central Wyoming emphasizing multi-disciplinary integrated basin analysis. The GSA/ExxonMobil Field Camp Scholar Award provides undergraduate students 2,000 each to attend the field camp of their choice based on diversity, economic/financial need, and merit. Finally, the GSA/ExxonMobil Field Camp Excellence Award provides one geologic field camp leader an award of 10,000 to assist with their summer field camp season based on safety awareness, diversity, and technical excellence. This non-profit/industry collaboration has proven very successful and in 2011 over 300 geology students and professors have applied for these awards.

  6. Geology of the west Bear Creek site

    SciTech Connect

    Lee, R.R.; Ketelle, R.H.

    1989-01-01

    A geological study was conducted at the Department of Energy's proposed ''tumulus'' low-level waste disposal site in west Bear Creek Valley on the Oak Ridge Reservation. The objective of the study was to describe the geologic characteristics of the site and to provide a foundation for concurrent geohydrologic studies. Methods for study included examination of existing rock core, acquisition of additional core, geophysical logging, study of sparse natural rock exposures, examination of weathered surficial bedrock, and acquisition of bedrock fracture orientation data. For construction of geologic cross sections and a geologic map, key subsurface data were projected to the surface using a typical bedrock attitude. The surface locations of these data were refined by examination of weathered bedrock. Consistent with the regional geologic setting and previous studies elsewhere in Bear Creek Valley, results of this study indicate that the site is underlain by generally uniform dipping strata of the Cambrian Conasauga Group. Detailed examination of the lithologic features of a portion of the Conasauga at the site indicates that direct application of regional stratigraphic nomenclature requires minor modification. Analysis of intermediate-scale (meter-scale) structural features leads to the development of two conceptual models. 17 refs., 11 figs.

  7. Impact, and its implications for geology

    NASA Technical Reports Server (NTRS)

    Marvin, Ursula B.

    1988-01-01

    The publication of seminal texts on geology and on meteoritics in the 1790s, laid the groundwork for the emergence of each discipline as a modern branch of science. Within the past three decades, impact cratering has become universally accepted as a process that sculptures the surfaces of planets and satellites throughout the solar system. Nevertheless, one finds in-depth discussions of impact processes mainly in books on the Moon or in surveys of the Solar System. The historical source of the separation between meteoritics and geology is easy to identify. It began with Hutton. Meteorite impact is an extraordinary event acting instantaneously from outside the Earth. It violates Hutton's principles, which were enlarged upon and firmly established as fundamental to the geological sciences by Lyell. The split between meteoritics and geology surely would have healed as early as 1892 if the investigations conducted by Gilbert (1843-1918) at the crater in northern Arizona had yielded convincing evidence of meteorite impact. The 1950s and 1960s saw a burgeoning of interest in impact processes. The same period witnessed the so-called revolution in the Earth Sciences, when geologists yielded up the idea of fixed continents and began to view the Earth's lithosphere as a dynamic array of horizontally moving plates. Plate tectonics, however, is fully consistent with the geological concepts inherited from Hutton: the plates slowly split, slide, and suture, driven by forces intrinsic to the globe.

  8. Conduct of Geologic Field Work During Planetary Exploration: Why Geology Matters

    NASA Technical Reports Server (NTRS)

    Eppler, Dean B.

    2010-01-01

    The science of field geology is the investigative process of determining the distribution of rock units and structures on a planet s surface, and it is the first order data set that informs all subsequent studies of a planet, such as geochemistry, geochronology, geophysics or remote sensing. These allied sciences, as important as they are, derive the basis of their understanding from the knowledge of the geology of a given location. When we go back to the Moon, and on to Mars, the surface systems we deploy will need to support the conduct of field geology if these endeavors are to be scientifically useful. This lecture will consider what field geology is about - why it s important, how we do it, how the conduct of field geology informs many other sciences, and how it will affect the design of surface systems and implementation of operations in the future.

  9. The Geologic History of Seawater

    NASA Astrophysics Data System (ADS)

    Holland, H. D.

    2003-12-01

    following account of his unsuccessful attempt to do so (Birch, 1756 and Black, 1966):Mr. Winthrop's letter written from Boston to Mr. Oldenburg was read, giving an account of the trials made by him at sea with the instrument for sounding of depths without a line, and with the vessel for drawing water from the bottom of the sea; both which proved successless, the former by reason of too much wind at the time of making soundings; the latter, on account of the leaking of the vessel. Capt. Taylor being to go soon to Virginia, and offering himself to make the same experiments, the society recommended to him the trying of the one in calm weather, and of the other with a stanch vessel.Mr. Hooke mentioning, that a better way might be suggested to make the experiment above-mentioned, was desired to think farther upon it, and to bring in an account thereof at the next meeting.A little more than one hundred years later, in the 1780s, John Walker (1966) lectured at Edinburgh on the saltness of the oceans. He marshaled all of the available data and concluded that "these reasons seem all to point to this, that the water of the ocean in respect to saltness is pretty much what it ever has been."In this opinion he disagreed with Halley (1715), who suggested that the salinity of the oceans has increased with time, and that the ratio of the total salt content of the oceans to the rate at which rivers deliver salt to the sea could be used to ascertain the age of the Earth. The first really serious attempt to measure geologic time by this method was made by Joly (1899). His calculations were refined by Clarke (1911), who inferred that the age of the ocean, since the Earth assumed its present form, is somewhat less than 100 Ma. He concluded, however, that "the problem cannot be regarded as definitely solved until all available methods of estimation shall have converged on one common conclusion." There was little appreciation in his approach for the magnitude of: (i) the outputs of salt from the

  10. Geology and MER target site characteristics along the southern rim of Isidis Planitia, Mars

    NASA Astrophysics Data System (ADS)

    Crumpler, L. S.; Tanaka, K. L.

    2003-12-01

    The southern rim of the Isidis basin contains one of the highest densities of valley networks, several restricted paleolake basins, and the stratigraphically lowest (oldest) terrain on Mars. Geologic mapping in Viking, MGS/MOC, and MOLA data, Odyssey/THEMIS data, and other multispectral data products supports the presence of extensive fans of debris and sediments deposited along the inner rim of the Isidis basin where large valleys enter the lowlands. Additional processes subsequent to the period of intense fluvial activity, including mass flow analogous to some glacial processes, have contributed to the materials accumulated on the margins of the Isidis basin. These have occurred along preexisting channels and valleys at the termini of major channels where they enter the plains along the highland-lowland boundary. If the abundant valley networks in highland terrains are the result of runoff accompanied by saturated groundwater flow, as has been suggested in previous studies of ancient fluvial highland terrains, then the extreme age and abundance of early valley networks in the Libya Montes highland rocks should have resulted in deposition of materials that record evidence for the long-term presence of water in the form of aqueous alteration of polycrystalline constituents. The material deposited along the basin margin is likely to consist of ancient altered highland rocks in several physical states (weathered, rounded, and angular) exposing both weathered and altered surfaces, and exposures of alteration profiles in fractured faces and unweathered material from rock interiors. Debris fans shed off the southern rim of Isidis Planitia should contain materials that have experienced possible saturated groundwater flow, residence within paleolake basins, and derivative materials deposited during the most fluvially intensive part of Martian geologic history. Many of these materials have also been reworked by ice-related processes. In situ measurements of the ancient

  11. Brine flow in heated geologic salt.

    SciTech Connect

    Kuhlman, Kristopher L.; Malama, Bwalya

    2013-03-01

    This report is a summary of the physical processes, primary governing equations, solution approaches, and historic testing related to brine migration in geologic salt. Although most information presented in this report is not new, we synthesize a large amount of material scattered across dozens of laboratory reports, journal papers, conference proceedings, and textbooks. We present a mathematical description of the governing brine flow mechanisms in geologic salt. We outline the general coupled thermal, multi-phase hydrologic, and mechanical processes. We derive these processes governing equations, which can be used to predict brine flow. These equations are valid under a wide variety of conditions applicable to radioactive waste disposal in rooms and boreholes excavated into geologic salt.

  12. The geologic history of Margaritifer basin, Mars

    NASA Astrophysics Data System (ADS)

    Salvatore, M. R.; Kraft, M. D.; Edwards, C. S.; Christensen, P. R.

    2016-03-01

    In this study, we investigate the fluvial, sedimentary, and volcanic history of Margaritifer basin and the Uzboi-Ladon-Morava outflow channel system. This network of valleys and basins spans more than 8000 km in length, linking the fluvially dissected southern highlands and Argyre basin with the northern lowlands via Ares Vallis. Compositionally, thermophysically, and morphologically distinct geologic units are identified and are used to place critical relative stratigraphic constraints on the timing of geologic processes in Margaritifer basin. Our analyses show that fluvial activity was separated in time by significant episodes of geologic activity, including the widespread volcanic resurfacing of Margaritifer basin and the formation of chaos terrain. The most recent fluvial activity within Margaritifer basin appears to terminate at a region of chaos terrain, suggesting possible communication between surface and subsurface water reservoirs. We conclude with a discussion of the implications of these observations on our current knowledge of Martian hydrologic evolution in this important region.

  13. Carbon dioxide capture and geological storage.

    PubMed

    Holloway, Sam

    2007-04-15

    Carbon dioxide capture and geological storage is a technology that could be used to reduce carbon dioxide emissions to the atmosphere from large industrial installations such as fossil fuel-fired power stations by 80-90%. It involves the capture of carbon dioxide at a large industrial plant, its transport to a geological storage site and its long-term isolation in a geological storage reservoir. The technology has aroused considerable interest because it can help reduce emissions from fossil fuels which are likely to remain the dominant source of primary energy for decades to come. The main issues for the technology are cost and its implications for financing new or retrofitted plants, and the security of underground storage.

  14. Chapter D in Geological Survey research 1964

    USGS Publications Warehouse

    ,

    1964-01-01

    This collection of 43 short papers is the last of the chapters of Geological Survey Research 1964. The papers report on scientific and economic results of current work by members of the Geologic, Conservation, Water Resources, and Topographic Divisions of the U.S. Geological Survey. Some of the papers present results of completed parts of continuing investigations; others announce new discoveries or preliminary results of investigations that will be discussed in greater detail in reports to be published in the future. Still others are. scientific notes of limited scope, and short papers on techniques and instrumentation. Chapter A of this series presents a summary of results of work done during the present fiscal year.

  15. System for fracturing an underground geologic formation

    DOEpatents

    Mace, Jonathan L.; Tappan, Bryce C.; Seitz, Gerald J.; Bronisz, Lawrence E.

    2017-03-14

    An explosive system for fracturing an underground geologic formation adjacent to a wellbore can comprise a plurality of explosive units comprising an explosive material contained within the casing, and detonation control modules electrically coupled to the plurality of explosive units and configured to cause a power pulse to be transmitted to at least one detonator of at least one of the plurality of explosive units for detonation of the explosive material. The explosive units are configured to be positioned within a wellbore in spaced apart positions relative to one another along a string with the detonation control modules positioned adjacent to the plurality of explosive units in the wellbore, such that the axial positions of the explosive units relative to the wellbore are at least partially based on geologic properties of the geologic formation adjacent the wellbore.

  16. The geologic history of Margaritifer basin, Mars

    USGS Publications Warehouse

    Salvatore, M. R.; Kraft, M. D.; Edwards, Christopher; Christensen, P.R.

    2016-01-01

    In this study, we investigate the fluvial, sedimentary, and volcanic history of Margaritifer basin and the Uzboi-Ladon-Morava (ULM) outflow channel system. This network of valleys and basins spans more than 8000 km in length, linking the fluvially dissected southern highlands and Argyre Basin with the northern lowlands via Ares Vallis. Compositionally, thermophysically, and morphologically distinct geologic units are identified and are used to place critical relative stratigraphic constraints on the timing of geologic processes in Margaritifer basin. Our analyses show that fluvial activity was separated in time by significant episodes of geologic activity, including the widespread volcanic resurfacing of Margaritifer basin and the formation of chaos terrain. The most recent fluvial activity within Margaritifer basin appears to terminate at a region of chaos terrain, suggesting possible communication between surface and subsurface water reservoirs. We conclude with a discussion of the implications of these observations on our current knowledge of Martian hydrologic evolution in this important region.

  17. Planetary Geology: Goals, Future Directions, and Recommendations

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Planetary exploration has provided a torrent of discoveries and a recognition that planets are not inert objects. This expanded view has led to the notion of comparative planetology, in which the differences and similarities among planetary objects are assessed. Solar system exploration is undergoing a change from an era of reconnaissance to one of intensive exploration and focused study. Analyses of planetary surfaces are playing a key role in this transition, especially as attention is focused on such exploration goals as returned samples from Mars. To assess how the science of planetary geology can best contribute to the goals of solar system exploration, a workshop was held at Arizona State University in January 1987. The participants discussed previous accomplishments of the planetary geology program, assessed the current studies in planetary geology, and considered the requirements to meet near-term and long-term exploration goals.

  18. Geologic time: The age of the Earth

    USGS Publications Warehouse

    Newman, William L.

    1977-01-01

    The Earth is very old 4 1/2 billion years or more according to recent estimates. This vast span of time, called geologic time by earth scientists and believed by some to reach back to the birth of the Solar System, is difficult if not impossible 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 man's centuries-old search for the key led to the beginning and nourished the growth of geologic science.

  19. A Geology Sampling System for Microgravity Bodies

    NASA Technical Reports Server (NTRS)

    Hood, Anthony; Naids, Adam

    2016-01-01

    Human exploration of microgravity bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this microgravity category and some are been discussed as potential mission targets. Obtaining geological samples for return to Earth will be a major objective for any mission to a microgravity body. Currently the knowledge base for geology sampling in microgravity is in its infancy. Humans interacting with non-engineered surfaces in microgravity environment pose unique challenges. In preparation for such missions a team at the NASA Johnson Space Center has been working to gain experience on how to safely obtain numerous sample types in such an environment. This paper describes the type of samples the science community is interested in, highlights notable prototype work, and discusses an integrated geology sampling solution.

  20. A Geology Sampling System for Small Bodies

    NASA Technical Reports Server (NTRS)

    Hood, A. D.; Naids, A. J.; Graff, T.; Abell, P.

    2015-01-01

    Human exploration of Small Bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this Small Bodies category and some are being discussed as potential mission tar-gets. Obtaining geological samples for return to Earth will be a major objective for any mission to a Small Body. Currently the knowledge base for geology sampling in microgravity is in its infancy. Furthermore, humans interacting with non-engineered surfaces in a microgravity environment poses unique challenges. In preparation for such missions, a team at the National Aeronautics and Space Administration (NASA) John-son Space Center (JSC) has been working to gain experience on how to safely obtain numerous sample types in such an environment. This abstract briefly summarizes the type of samples the science community is interested in, discusses an integrated geology sampling solution, and highlights some of the unique challenges associated with this type of exploration.

  1. A Geology Sampling System for Small Bodies

    NASA Technical Reports Server (NTRS)

    Naids, Adam J.; Hood, Anthony D.; Abell, Paul; Graff, Trevor; Buffington, Jesse

    2016-01-01

    Human exploration of microgravity bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this microgravity category and some are being discussed as potential mission targets. Obtaining geological samples for return to Earth will be a major objective for any mission to a small body. Currently, the knowledge base for geology sampling in microgravity is in its infancy. Humans interacting with non-engineered surfaces in microgravity environment pose unique challenges. In preparation for such missions a team at the NASA Johnson Space Center has been working to gain experience on how to safely obtain numerous sample types in such an environment. This paper describes the type of samples the science community is interested in, highlights notable prototype work, and discusses an integrated geology sampling solution.

  2. Cassini's geological and compositional view of Tethys

    NASA Astrophysics Data System (ADS)

    Stephan, Katrin; Wagner, Roland; Jaumann, Ralf; Clark, Roger N.; Cruikshank, Dale P.; Brown, Robert H.; Giese, Bernd; Roatsch, Thomas; Filacchione, Gianrico; Matson, Dennis; Ore, Cristina Dalle; Capaccioni, Fabrizio; Baines, Kevin H.; Rodriguez, Sebastien; Krupp, Norbert; Buratti, Bonnie J.; Nicholson, Phil D.

    2016-08-01

    The Saturnian satellite Tethys exhibits geological and spectral properties, whose appearance, nature and spatial distribution partly mirror those identified on the neighboring satellites Dione and Rhea or fit to the picture how spectral surface properties are expected to change from one satellite to the other within the inner Saturnian system. However, we also identified spectral variations that are unique in the Saturnian system. Whereas geologically young surface features are characterized by pure H2O-ice composition with relatively large particles, which match the particle sizes measured for fresh surface features also on Dione and Rhea, geologically old weathered regions are dominated by submicron-sized ice particles. Our investigations confirm that the Odysseus impact event did not cause the formation of Tethys' extended graben system Ithaca Chasma. On the contrary, Odysseus might be responsible for the N-S trending 'icy' bands that mark Tethys' surface in the center of its leading and trailing hemisphere.

  3. Geology of the Apollo 17 site

    NASA Technical Reports Server (NTRS)

    Muehlberger, W. R.

    1992-01-01

    The Apollo 17 landing site was unique in several aspects: (1) it was the only site that was not selected from telescopic-based geologic interpretation--interest in the site was generated by the visual observations of Al Worden, Apollo 15 Command Module pilot, who interpreted dark-haloed craters as possible cinder cones; (2) instead of 20-m-resolution photographs, as was the norm for all earlier missions, this site had Apollo 15 panoramic camera photography coverage that had 2-m resolution; and (3) it had a geologist-astronaut aboard who was intimately involved in all stages of planning and mission operation, and was also instrumental in the design of a long-handled sample bag holder that eliminated the need for crew to dismount before collecting a sample, which then permitted sampling between major stations. Details of site geology, sample description, and geologic synthesis of the site as viewed from studies through 1976 are summarized.

  4. Geologic coal assessment: The interface with economics

    USGS Publications Warehouse

    Attanasi, E.D.

    2001-01-01

    Geologic resource assessments describe the location, general characteristics, and estimated volumes of resources, whether in situ or technically recoverable. Such compilations are only an initial step in economic resource evaluation. This paper identifies, by examples from the Illinois and Appalachian basins, the salient features of a geologic assessment that assure its usefulness to downstream economic analysis. Assessments should be in sufficient detail to allocate resources to production units (mines or wells). Coal assessments should include the spatial distribution of coal bed characteristics and the ability to allocate parts of the resource to specific mining technologies. For coal bed gas assessment, the production well recoveries and well deliverability characteristics must be preserved and the risk structure should be specified so dryholes and noncommercial well costs are recovered by commercially successful wells. ?? 2001 International Association for Mathematical Geology.

  5. Geographic information systems (GIS) for geologic mapping

    SciTech Connect

    Schock, S.C. . Center for Environmental Research Information)

    1993-03-01

    The computer-based Geographic Information System (GIS) is a powerful and versatile tool for preparation of geologic maps. Using GIS different types of geographically oriented information can be displayed on a common base in a flexible format that facilitates examination of relationships between the types of information. In addition, text-based and graphic information (attributes) from separate databases can be attached to points, lines or areas within the different map layers. Although GIS has enormous potential for geologic mapping, it must be used with care. Key considerations when using GIS include realistic representation of the geology, choice of an appropriate scale for the maps, and comparison of the computer-generated maps with field observations to maintain quality control. In building multilayer GIS maps, the data sources must be at a scale appropriate to the intended use. Information derived from diverse sources must be examined carefully to assure that it is valid at the scale of representation required. Examples of GIS products created for one purpose, but potentially misused for a different purpose, include formation contacts (lines) on a regional geologic map scaled up for a facility siting study or well locations on a small-scale location map subsequently contoured for contaminant plume prediction at a very large scale. In using GIS to prepare geologic maps, it is essential to have a clear rationale for the map and use an appropriate scale to depict the various layers of information. The authors of GIS-based geologic maps must be aware that the attractive, polished appearance of their products may tempt some end users to stretch and misinterpret the information displayed.

  6. Geological Mapping Using Machine Learning Algorithms

    NASA Astrophysics Data System (ADS)

    Harvey, A. S.; Fotopoulos, G.

    2016-06-01

    Remotely sensed spectral imagery, geophysical (magnetic and gravity), and geodetic (elevation) data are useful in a variety of Earth science applications such as environmental monitoring and mineral exploration. Using these data with Machine Learning Algorithms (MLA), which are widely used in image analysis and statistical pattern recognition applications, may enhance preliminary geological mapping and interpretation. This approach contributes towards a rapid and objective means of geological mapping in contrast to conventional field expedition techniques. In this study, four supervised MLAs (naïve Bayes, k-nearest neighbour, random forest, and support vector machines) are compared in order to assess their performance for correctly identifying geological rocktypes in an area with complete ground validation information. Geological maps of the Sudbury region are used for calibration and validation. Percent of correct classifications was used as indicators of performance. Results show that random forest is the best approach. As expected, MLA performance improves with more calibration clusters, i.e. a more uniform distribution of calibration data over the study region. Performance is generally low, though geological trends that correspond to a ground validation map are visualized. Low performance may be the result of poor spectral images of bare rock which can be covered by vegetation or water. The distribution of calibration clusters and MLA input parameters affect the performance of the MLAs. Generally, performance improves with more uniform sampling, though this increases required computational effort and time. With the achievable performance levels in this study, the technique is useful in identifying regions of interest and identifying general rocktype trends. In particular, phase I geological site investigations will benefit from this approach and lead to the selection of sites for advanced surveys.

  7. Aqueous Alteration of Basalts: Earth, Moon, and Mars

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.

    2007-01-01

    The geologic processes responsible for aqueous alteration of basaltic materials on Mars are modeled beginning with our knowledge of analog processes on Earth, i.e., characterization of elemental and mineralogical compositions of terrestrial environments where the alteration and weathering pathways related to aqueous activity are better understood. A key ingredient to successful modeling of aqueous processes on Mars is identification of phases that have formed by those processes. The purpose of this paper is to describe what is known about the elemental and mineralogical composition of aqueous alteration products of basaltic materials on Mars and their implications for specific aqueous environments based upon our knowledge of terrestrial systems. Although aqueous alteration has not occurred on the Moon, it is crucial to understand the behaviors of basaltic materials exposed to aqueous environments in support of human exploration to the Moon over the next two decades. Several methods or indices have been used to evaluate the extent of basalt alteration/weathering based upon measurements made at Mars by the Mars Exploration Rover (MER) Moessbauer and Alpha Particle X-Ray Spectrometers. The Mineralogical Alteration Index (MAI) is based upon the percentage of total Fe (Fe(sub T)) present as Fe(3+) in alteration products (Morris et al., 2006). A second method is the evaluation of compositional trends to determine the extent to which elements have been removed from the host rock and the likely formation of secondary phases (Nesbitt and Young, 1992; Ming et al., 2007). Most of the basalts that have been altered by aqueous processes at the two MER landing sites in Gusev crater and on Meridiani Planum have not undergone extensive leaching in an open hydrolytic system with the exception of an outcrop in the Columbia Hills. The extent of aqueous alteration however ranges from relatively unaltered to pervasively altered materials. Several experimental studies have focused upon

  8. Fallon FORGE 3D Geologic Model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    An x,y,z scattered data file for the 3D geologic model of the Fallon FORGE site. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  9. Economic geology of lunar Helium-3

    NASA Technical Reports Server (NTRS)

    Schmitt, Harrison H.

    1988-01-01

    Economic geology evaluation of lunar He-3 should answer the question: Can lunar He-3 be sold on Earth with sufficient profit margins and low enough risk to attract capital investment in the enterprise. Concepts that relate to economic geology of recovering He-3 from the lunar maria are not new to human experience. A parametric cost and technology evaluation scheme, based on existing and future data, is required to qualitatively and quantitatively assess the comprehensive economic feasibility and return on investment of He-3 recovery from the lunar maria. There are also many political issues which must be considered as a result of nuclear fusion and lunar mining.

  10. Geologic utility of small-scale airphotos

    NASA Technical Reports Server (NTRS)

    Clark, M. M.

    1969-01-01

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

  11. Economic geology of lunar Helium-3

    NASA Astrophysics Data System (ADS)

    Schmitt, Harrison H.

    1988-09-01

    Economic geology evaluation of lunar He-3 should answer the question: Can lunar He-3 be sold on Earth with sufficient profit margins and low enough risk to attract capital investment in the enterprise. Concepts that relate to economic geology of recovering He-3 from the lunar maria are not new to human experience. A parametric cost and technology evaluation scheme, based on existing and future data, is required to qualitatively and quantitatively assess the comprehensive economic feasibility and return on investment of He-3 recovery from the lunar maria. There are also many political issues which must be considered as a result of nuclear fusion and lunar mining.

  12. Lunar Geologic Mapping Program: 2008 Update

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

  13. Arabian plate hydrocarbon geology and potential

    SciTech Connect

    Beydoun, Z.R.

    1991-01-01

    This book provides a thought-provoking, succinct presentation of the geologic evolution and hydrocarbon potential of the world's most prolific petroleum province. The fascinating subjects discussed and documented include: What are the unique geologic factors that make the Middle East such a prolific province Where are the future Mesozoic and Tertiary plays What is the virtually untapped potential of the Paleozoic section What are the play potentials for underexplored areas such as Jordan, Syria, Yemen How are deeper drilling results shaping and modifying concepts of the Arabian plate history and pointing the way to future hydrocarbon targets

  14. Geologic Map of the Thaumasia Region, Mars

    USGS Publications Warehouse

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

    2001-01-01

    The geology of the Thaumasia region (fig. 1, sheet 3) includes a wide array of rock materials, depositional and erosional landforms, and tectonic structures. The region is dominated by the Thaumasia plateau, which includes central high lava plains ringed by highly deformed highlands; the plateau may comprise the ancestral center of Tharsis tectonism (Frey, 1979; Plescia and Saunders, 1982). The extensive structural deformation of the map region, which is without parallel on Mars in both complexity and diversity, occurred largely throughout the Noachian and Hesperian periods (Tanaka and Davis, 1988; Scott and Dohm, 1990a). The deformation produced small and large extensional and contractional structures (fig. 2, sheet 3) that resulted from stresses related to the formation of Tharsis (Frey, 1979; Wise and others, 1979; Plescia and Saunders, 1982; Banerdt and others, 1982, 1992; Watters and Maxwell, 1986; Tanaka and Davis, 1988; Francis, 1988; Watters, 1993; Schultz and Tanaka, 1994), from magmatic-driven uplifts, such as at Syria Planum (Tanaka and Davis, 1988; Dohm and others, 1998; Dohm and Tanaka, 1999) and central Valles Marineris (Dohm and others, 1998, Dohm and Tanaka, 1999), and from the Argyre impact (Wilhelms, 1973; Scott and Tanaka, 1986). In addition, volcanic, eolian, and fluvial processes have highly modified older surfaces in the map region. Local volcanic and tectonic activity often accompanied episodes of valley formation. Our mapping depicts and describes the diverse terrains and complex geologic history of this unique ancient tectonic region of Mars. The geologic (sheet 1), paleotectonic (sheet 2), and paleoerosional (sheet 3) maps of the Thaumasia region were compiled on a Viking 1:5,000,000-scale digital photomosaic base. The base is a combination of four quadrangles: the southeast part of Phoenicis Lacus (MC–17), most of the southern half of Coprates (MC–18), a large part of Thaumasia (MC–25), and the northwest margin of Argyre (MC–26

  15. Method of fracturing a geological formation

    DOEpatents

    Johnson, James O.

    1990-01-01

    An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

  16. Recent advances in geologic mapping by radar

    NASA Technical Reports Server (NTRS)

    Farr, T. G.

    1984-01-01

    Quantitative techniques are available which allow the analysis of SAR images for the derivation of geological surface and process data. In conjunction with calibrated radar sensors operating at several incidence angles, wavelengths, and polarizations, the compilation of multiparameter radar signatures of lithological and geomorphic units can accordingly proceed for geological mapping in unknown areas. While radar image tone can be used in arid zones to derive surface micromorphology, heavily vegetated tropical regions require the analysis of radar image texture by means of Fourier techniques which decompose the image into bandpasses that represent different scales of texture.

  17. Impact process: an important geological phenomenon.

    PubMed

    Skala, R

    1996-01-01

    The impact process was for a long period of time, even after a wider acceptance among the geological community, considered to be a marginal phenomenon in the Earth sciences. The first decade or two have showed an importance of the process itself and consequent events only too clearly. The present paper is a review describing the history and development of the impact hypothesis, structure and origin of impact craters, influence of huge impacts on the living environment and other aspects of the impact process from the point of view of geology s.l.

  18. Geologic Mapping of Ascraeus Mons, Mars

    NASA Technical Reports Server (NTRS)

    Mohr, K. J.; Williams, D. A.; Garry, W. B.

    2016-01-01

    Ascraeus Mons (AM) is the northeastern most large shield volcano residing in the Tharsis province on Mars. We are funded by NASA's Mars Data Analysis Program to complete a digital geologic map based on the mapping style. Previous mapping of a limited area of these volcanoes using HRSC images (13-25 m/pixel) revealed a diverse distribution of volcanic landforms within the calderas, along the flanks, rift aprons, and surrounding plains. The general scientific objectives for which this mapping is based is to show the different lava flow morphologies across AM to better understand the evolution and geologic history.

  19. Geological Data Preservation Program Receives Bipartisan Support

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2014-09-01

    More than 22 million vertical feet of geologic cores and cuttings fill the Kentucky Geological Survey's Well Sample and Core Library in Lexington. The materials are from at least 22,000 sites within Kentucky—including collections from oil and gas exploration operations, coal and other mining companies, highway construction projects, environmental studies, and federal facilities such as Fort Knox—and they are straining the 15-year-old facility to the point where there is no room to keep everything, according to geologist Patrick Gooding, the library manager.

  20. Reports of Planetary Geology Program, 1981

    NASA Technical Reports Server (NTRS)

    Holt, H. E. (Compiler)

    1981-01-01

    Abstracts of 205 reports from Principal investigators of NASA's Planetary Geology Program succinctly summarize work conducted and reflect the significant accomplishments. The entries are arranged under the following topics: (1) Saturnian satellites; (2) asteroids, comets and Galilean satellites; (3) cratering processes and landform development; (4) volcanic processes and landforms; (5) Aerolian processes and landforms; (6) fluvial, preglacial, and other processes of landform development; (7) Mars polar deposits, volatiles, and climate; (8) structure, tectonics, and stratigraphy; (9) remote sensing and regolith chemistry; (10) cartography and geologic mapping; and (11) special programs.

  1. Automated geologic mapping using rock reflectances.

    NASA Technical Reports Server (NTRS)

    Watson, R. D.; Rowan, L. C.

    1971-01-01

    Investigation of the feasibility of preparing geologic maps automatically through computer processing of calibrated narrow-band visible and near IR reflectivity data collected with a 12-channel scanner. Five procedures were followed in the computer analysis of the radiances recorded as voltages on analog magnetic tape. Three recognition maps have been generated iteratively using a progressively more complex classification scheme. The overall accuracy of the first recognition map was 80%, but the discrimination of the limestone and dolomite was only 50-60%. All three maps are very accurate outcrop maps. The results demonstrate the feasibility of automated geologic mapping in this relatively simple setting.

  2. OneGeology Web Services and Portal as a global geological SDI - latest standards and technology

    NASA Astrophysics Data System (ADS)

    Duffy, Tim; Tellez-Arenas, Agnes

    2014-05-01

    The global coverage of OneGeology Web Services (www.onegeology.org and portal.onegeology.org) achieved since 2007 from the 120 participating geological surveys will be reviewed and issues arising discussed. Recent enhancements to the OneGeology Web Services capabilities will be covered including new up to 5 star service accreditation scheme utilising the ISO/OGC Web Mapping Service standard version 1.3, core ISO 19115 metadata additions and Version 2.0 Web Feature Services (WFS) serving the new IUGS-CGI GeoSciML V3.2 geological web data exchange language standard (http://www.geosciml.org/) with its associated 30+ IUGS-CGI available vocabularies (http://resource.geosciml.org/ and http://srvgeosciml.brgm.fr/eXist2010/brgm/client.html). Use of the CGI simpelithology and timescale dictionaries now allow those who wish to do so to offer data harmonisation to query their GeoSciML 3.2 based Web Feature Services and their GeoSciML_Portrayal V2.0.1 (http://www.geosciml.org/) Web Map Services in the OneGeology portal (http://portal.onegeology.org). Contributing to OneGeology involves offering to serve ideally 1:1000,000 scale geological data (in practice any scale now is warmly welcomed) as an OGC (Open Geospatial Consortium) standard based WMS (Web Mapping Service) service from an available WWW server. This may either be hosted within the Geological Survey or a neighbouring, regional or elsewhere institution that offers to serve that data for them i.e. offers to help technically by providing the web serving IT infrastructure as a 'buddy'. OneGeology is a standards focussed Spatial Data Infrastructure (SDI) and works to ensure that these standards work together and it is now possible for European Geological Surveys to register their INSPIRE web services within the OneGeology SDI (e.g. see http://www.geosciml.org/geosciml/3.2/documentation/cookbook/INSPIRE_GeoSciML_Cookbook%20_1.0.pdf). The Onegeology portal (http://portal.onegeology.org) is the first port of call for anyone

  3. ALTERATION OF U(VI)-PHASES UNDER OXIDIZING CONDITIONS

    SciTech Connect

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

    2006-02-21

    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.

  4. Preliminary geologic map of the eastern Willapa Hills, Cowlitz, Lewis, and Wahkiakum Counties, Washington

    USGS Publications Warehouse

    Wells, Ray E.; Sawlan, Michael G.

    2014-01-01

    This digital map database and the PDF derived from the database were created from the analog geologic map: Wells, R.E. (1981), “Geologic map of the eastern Willapa Hills, Cowlitz, Lewis, and Wahkiakum Counties, Washington.” The geodatabase replicates the geologic mapping of the 1981 report with minor exceptions along water boundaries and also along the north and south map boundaries. Slight adjustments to contacts along water boundaries were made to correct differences between the topographic base map used in the 1981 compilation (analog USGS 15-minute series quadrangle maps at 1:62,500 scale) and the base map used for this digital compilation (scanned USGS 7.5-minute series quadrangle maps at 1:24,000 scale). These minor adjustments, however, did not materially alter the geologic map. No new field mapping was performed to create this digital map database, and no attempt was made to fit geologic contacts to the new 1:24,000 topographic base, except as noted above. We corrected typographical errors, formatting errors, and attribution errors (for example, the name change of Goble Volcanics to Grays River Volcanics following current State of Washington usage; Walsh and others, 1987). We also updated selected references, substituted published papers for abstracts, and cited published radiometric ages for the volcanic and plutonic rocks. The reader is referred to Magill and others (1982), Wells and Coe (1985), Walsh and others (1987), Moothart (1993), Payne (1998), Kleibacker (2001), McCutcheon (2003), Wells and others (2009), Chan and others (2012), and Wells and others (in press) for subsequent interpretations of the Willapa Hills geology.

  5. Magellan stereo images and Venusian geology

    NASA Technical Reports Server (NTRS)

    Moore, H. J.; Saunders, R. S.; Plaut, Jeffrey J.; Parker, T. J.

    1992-01-01

    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 planetary bodies. Three sets of images with different viewing conditions have been acquired: (1) left-looking with variable incidence angles (cycle 1 profile), (2) right-looking with nearly constant incidence angles (cycle 2 profile), and (3) left-looking with variable incidence angles that are almost always smaller than those in (1) (cycle 3 profiles). The unique data provided by paired images of the same scene with different incidence angles arises from image displacements caused by the relief of individual landforms at scales comparable to the ground-range and azimuth resolutions of the images. There are two aspects of the data: (1) Stereopsis achieved by simultaneous viewing of paired left-looking images of the same scene permits three-dimensional perception and interpretation of the morphologies of landforms at resolutions much finer than the altimetry footprints. (2) Measurements of differences of image displacements (parallax) on paired images with known imaging geometries provide quantitative estimates of the relief and shapes of landforms. The potential scientific contributions of the data can be grouped into two interrelated classes: (A) geologic mapping, analysis, and interpretation and (B) topical studies that involve topographic measurements. Stereopsis, without quantitative measurements, enhances geologic mapping, analysis, and interpretation of the rock units of Venus to a degree that cannot be overestimated. In geologic mapping, assemblages of landforms, assessments of backscatter and variations in backscatter, and fine-scale topography are used to define and characterize geologic map units that represent laterally continuous deposits or rock units. Stereopsis adds the important dimension of local relief

  6. A SKOS-based multilingual thesaurus of geological time scale for interoperability of online geological maps

    NASA Astrophysics Data System (ADS)

    Ma, Xiaogang; Carranza, Emmanuel John M.; Wu, Chonglong; van der Meer, Freek D.; Liu, Gang

    2011-10-01

    The usefulness of online geological maps is hindered by linguistic barriers. Multilingual geoscience thesauri alleviate linguistic barriers of geological maps. However, the benefits of multilingual geoscience thesauri for online geological maps are less studied. In this regard, we developed a multilingual thesaurus of geological time scale (GTS) to alleviate linguistic barriers of GTS records among online geological maps. We extended the Simple Knowledge Organization System (SKOS) model to represent the ordinal hierarchical structure of GTS terms. We collected GTS terms in seven languages and encoded them into a thesaurus by using the extended SKOS model. We implemented methods of characteristic-oriented term retrieval in JavaScript programs for accessing Web Map Services (WMS), recognizing GTS terms, and making translations. With the developed thesaurus and programs, we set up a pilot system to test recognitions and translations of GTS terms in online geological maps. Results of this pilot system proved the accuracy of the developed thesaurus and the functionality of the developed programs. Therefore, with proper deployments, SKOS-based multilingual geoscience thesauri can be functional for alleviating linguistic barriers among online geological maps and, thus, improving their interoperability.

  7. Systematics of hydrothermal alteration at the volcanic-hosted Falun Zn-Pb-Cu-(Au-Ag) deposit - implications for ore genesis, structure and exploration in a 1.9 Ga ore district, Fennoscandian Shield, Sweden

    NASA Astrophysics Data System (ADS)

    Kampmann, Tobias C.; Jansson, Nils J.; Stephens, Michael B.; Majka, Jarosław

    2016-04-01

    strongly subordinate. Pre-metamorphic alteration in the proximal hydrothermally altered zone is characterized by general depletion in Na and Ca, and a strong enrichment in Mg and Fe. Pre-metamorphic alteration assemblages of Mg- or Fe-chlorite, sericite and talc can account for the observed mineral associations in the altered rocks. During metamorphism, strongly Mg-enriched altered rocks yielded Mg-rich biotite and cordierite porphyroblasts, whereas Fe-enriched altered rocks typically have Fe-rich biotite and garnet porphyroblasts dominated by the cations Fe and Mn. The less aluminous quartz-anthophyllite rocks could have formed from rocks enriched in talc. The nature of the precursor, style of hydrothermal alteration and mineralogy at Falun are characteristic of a metamorphosed volcanogenic massive sulphide (VMS) deposit. The zone of intense chlorite-style alteration of rhyolitic precursor rocks envelops the formerly mined sulphide ore bodies on all sides of the deposit. These spatial relationships are consistent with a previously suggested structural model, wherein the mineralization is hosted by a steeply plunging, D2 sheath fold with no preserved stratigraphic hanging wall in the core of the structure. The parts of other sulphide deposits in the 1.9 Ga ore district lacking good stratigraphic control and previously considered as barren hanging-wall rocks may have a higher exploration potential for base metals than previously thought.

  8. Digital Geologic Mapping and Integration with the Geoweb: The Death Knell for Exclusively Paper Geologic Maps

    NASA Astrophysics Data System (ADS)

    House, P. K.

    2008-12-01

    The combination of traditional methods of geologic mapping with rapidly developing web-based geospatial applications ('the geoweb') and the various collaborative opportunities of web 2.0 have the potential to change the nature, value, and relevance of geologic maps and related field studies. Parallel advances in basic GPS technology, digital photography, and related integrative applications provide practicing geologic mappers with greatly enhanced methods for collecting, visualizing, interpreting, and disseminating geologic information. Even a cursory application of available tools can make field and office work more enriching and efficient; whereas more advanced and systematic applications provide new avenues for collaboration, outreach, and public education. Moreover, they ensure a much broader audience among an immense number of internet savvy end-users with very specific expectations for geospatial data availability. Perplexingly, the geologic community as a whole is not fully exploring this opportunity despite the inevitable revolution in portends. The slow acceptance follows a broad generational trend wherein seasoned professionals are lagging behind geology students and recent graduates in their grasp of and interest in the capabilities of the geoweb and web 2.0 types of applications. Possible explanations for this include: fear of the unknown, fear of learning curve, lack of interest, lack of academic/professional incentive, and (hopefully not) reluctance toward open collaboration. Although some aspects of the expanding geoweb are cloaked in arcane computer code, others are extremely simple to understand and use. A particularly obvious and simple application to enhance any field study is photo geotagging, the digital documentation of the locations of key outcrops, illustrative vistas, and particularly complicated geologic field relations. Viewing geotagged photos in their appropriate context on a virtual globe with high-resolution imagery can be an

  9. Significant achievements in the Planetary Geology Program. [geologic processes, comparative planetology, and solar system evolution

    NASA Technical Reports Server (NTRS)

    Head, J. W. (Editor)

    1978-01-01

    Developments reported at a meeting of principal investigators for NASA's planetology geology program are summarized. Topics covered include: constraints on solar system formation; asteriods, comets, and satellites; constraints on planetary interiors; volatiles and regoliths; instrument development techniques; planetary cartography; geological and geochemical constraints on planetary evolution; fluvial processes and channel formation; volcanic processes; Eolian processes; radar studies of planetary surfaces; cratering as a process, landform, and dating method; and the Tharsis region of Mars. Activities at a planetary geology field conference on Eolian processes are reported and techniques recommended for the presentation and analysis of crater size-frequency data are included.

  10. Geological monitoring of Surtsey, Iceland, 1967-1998

    USGS Publications Warehouse

    Jakobsson, Sveinn P.; Gudmundsson, Gudmundur; Moore, James G.

    2000-01-01

    Aspects of the geological monitoring of the volcanic island of Surtsey 1967-1998, are described. A hydrothermal system was developed within the tephra craters in late 1966 to early 1967. Temperatures in a drill hole, situated at the eastern border of the hydrothermal area, indicate that the hydrothermal system at that site has been cooling at an average rate of ≤ 1°C per year since 1980. The tephra was altered rapidly within the hydrothermal area, producing the first visible palagonite tuff in 1969. A substantial part of the tephra pile above sea level was probably converted to tuff by 1972. The visible area of tuff has gradually increased since then, primarily due to erosion of tephra at the surface. By 1998 52% of the exposed tephra area had been converted to palagonite tuff. By volume, however, some 80-85% of the tephra pile above sea level has been converted to tuff in 1998. The area of Surtsey has shrunk from its original 2.65 km2 (1967) to 1.47 km2 (1998) due to marine abrasion. The geological formations on Surtsey have, however, responded quite variably to erosion. The tephra pile was easily eroded, but marine abrasion. The central core of palagonite tuff is estimated to be ≤0.39 km2. Statistical estimation of models of the decreases of Surtsey indicate that it will last for a long time. The numerical experiments indicate that it will take over 100 years until only the palagonite tuff core is left. It is postulated that the final remnany of Surtsey before complete destruction will be a palagonite tuff crag, comparable to those of the other islands in the Vestmannaeyjar archipelago.

  11. The Geology of the Florida Keys.

    ERIC Educational Resources Information Center

    Shinn, Eugene A.

    1988-01-01

    Describes some of the ancient geologic history of the Florida Keys from Key Largo to Key West including the effects of glaciers, sea level rise, reef distribution, spurs and grooves, backstepping and ecological zonation, growth rates and erosion. Predicts future changes in this area. (CW)

  12. Life on Guam: Geology. 1977 Edition.

    ERIC Educational Resources Information Center

    Elkins, Gail; And Others

    As part of an updated series of activity oriented educational materials dealing with aspects of the Guam environment, this publication focuses on the physical environment of Guam through an introduction to the geology of Guam. Contents include the formation of Guam, weathering and erosion, earthquakes, soil, and water. Activities investigate…

  13. Geology of magma systems: background and review

    SciTech Connect

    Peterfreund, A.R.

    1981-03-01

    A review of basic concepts and current models of igneous geology is presented. Emphasis is centered on studies of magma generation, ascent, emplacement, evolution, and surface or near-surface activity. An indexed reference list is also provided to facilitate future investigations.

  14. Geology of the USSR (Chapter IV).

    DTIC Science & Technology

    1979-10-05

    siny1a coniferaq, Araucariaceae, Podozamites and ancipn- Pinaceae . DOC 7q126601 PAGE 16 v" v "v v - 2 34 Fiq. 2. Schematic geologic map/ctiart/cdrd of...of coniferous ones (Araucariaceae, Podozamites, Picea, Pinaceae - 50o/o) and a large quantity of pollen of Bennettitales and ginkgoic - 15o/o

  15. Reginal Geology of Hadley Rille, part F

    NASA Technical Reports Server (NTRS)

    Howard, K. A.; Head, J. W.

    1972-01-01

    Local geology of Hadley Rille near the landing site of Apollo 15 is described. Orbital photography from the Hasselblad, metric, and panoramic cameras is used to study regional relationships of the rille. The shape of the rille due to various natural causes is examined, along with stratigraphic measurements of mare materials.

  16. Teaching Geology at San Quentin State Prison

    NASA Astrophysics Data System (ADS)

    D'Alessio, M. A.; Pehl, J.; Ferrier, K. L.; Pehl, C. W.

    2004-12-01

    The students enrolled in our Geology 215 class are about as on-traditional as it gets. They range in age from about 20 - 50 years old, they are all male, all from under-represented ethnic groups, and they are all serving time in one of the country's most notorious prisons. We teach in a degree-granting community college program inside California's San Quentin State Prison. The program is run entirely by volunteers, and students who participate in educational programs like ours are about 5 times less likely to return to prison than the general inmate population in California. The prison population of California is ethnically diverse, though minorities are present in higher proportion than in the general population. Last semester, our geology class happened to be composed entirely of minorities even though the college program serves the full spectrum of the prison population. While some trends in geoscience education encourage the use of technology in the classroom, security restrictions prevent us from using even some of the simplest visual aids. Faced with these challenges, we have developed an inquiry-based syllabus for an introductory Geology class at the community college level. We find that kinaesthetic learning activities such as urban geologic mapping and acting out plate tectonic motions from ridge to trench (complete with magnetic pole polarity shifts) are not only possible in restricted learning environments, but they promote student learning in unexpected ways.

  17. The Geology of Delaware Coastal Environments.

    ERIC Educational Resources Information Center

    Lewis, Robert E.

    This teachers' manual provides model classroom lessons in earth science. It is specially designed to be used with John C. Kraft's A GUIDE TO THE GEOLOGY OF DELAWARE'S COASTAL ENVIRONMENT. The lessons suggest an approach for using the guide in the science classroom and in field studies. The manual can be used as a complete unit, or individual…

  18. Environmental geology in loess areas of China

    SciTech Connect

    Sun Jianzhong )

    1988-08-01

    There are several unfavorable geological hazards in the loess area of China. The major purposes of environmental geology studies in this region are to expound the causes of these hazards and to determine treatments. Geological hazards include endemic diseases, depletion of groundwater, land subsidence, ground fissures, soil erosion, and collapsibility of loess. This article is a summary of studies regarding these hazards. Keshan disease and Kaschin-Beck disease, for example, can be prevented and cured by adding selenates to table salt. Ponds can be constructed on the loess plateau and dikes around farmlands to collect rainfall to recharge groundwater resources. Excess extraction of groundwater is the major cause of land subsidence. Ground fissures in Xi'an are primarily caused by tectonics, but over-extraction of ground water strengthens its activity. Observation stations should be established in order to forecast and prevent landslides. Planting trees in a regional shelterbelt is the primary measure necessary to prevent soil erosion. As a result of these geological studies, valuable experience in preventing collapse of loess in China has been gained.

  19. Geological terrains and crater frequencies on Ariel

    USGS Publications Warehouse

    Plescia, J.B.

    1987-01-01

    The southern hemisphere of Ariel, a satellite of Uranus, can be divided into several terrain types. Data on the size-frequency distribution of craters for those different terrain types indicate that these terrains formed over a relatively short period of time. Much information on Ariel's geological history can be gained from these data. ?? 1987 Nature Publishing Group.

  20. The United States Geological Survey Library System

    USGS Publications Warehouse

    ,

    1994-01-01

    The U.S. Geological Survey Library, established in 1882, is one of the largest earth science libraries in the world. The Library System consists of the headquarters library in Reston, Virginia, and three branch libraries in Denver, Colorado; Flagstaff, Arizona; and Menlo Park, California

  1. The emerging Medical and Geological Association.

    USGS Publications Warehouse

    Finkelman, R.B.; Centeno, J.A.; Selinus, O.

    2005-01-01

    The impact on human health by natural materials such as water, rocks, and minerals has been known for thousands of years but there have been few systematic, multidisciplinary studies on the relationship between geologic materials and processes and human health (the field of study commonly referred to as medical geology). In the past few years, however, there has been a resurgence of interest in medical geology. Geoscientists working with medical researchers and public health scientists have made important contributions to understanding novel exposure pathways and causes of a wide range of environmental health problems such as: exposure to toxic levels of trace essential and non-essential elements such as arsenic and mercury; trace element deficiencies; exposure to natural dusts and to radioactivity; naturally occurring organic compounds in drinking water; volcanic emissions, etc. By linking with biomedical/public health researchers geoscientists are finally taking advantage of this age-old opportunity to help mitigate environmental health problems. The International Medical Geology Association has recently been formed to support this effort.

  2. Marine geology: A planet earth perspective

    SciTech Connect

    Anderson, R.N.

    1986-01-01

    This text provides coverage of the basic geology of the marine development. It starts with the formation of the oceans using plate tectonics, continues with discussions of the mid-ocean ridges, and concludes with coverage of the formation and deformation of the continents.

  3. Forensic Analysis using Geological and Geochemical Techniques

    NASA Astrophysics Data System (ADS)

    Hoogewerff, J.

    2009-04-01

    Due to the globalisation of legal (and illegal) trade there is an increasing demand for techniques which can verify the geographical origin and transfer routes of many legal and illegal commodities and products. Although geological techniques have been used in forensic investigations since the emergence of forensics as a science in the late eighteen hundreds, the last decade has seen a marked increase in geo-scientists initiating concept studies using the latest analytical techniques, including studying natural abundance isotope variations, micro analysis with laser ablation ICPMS and geochemical mapping. Most of the concept studies have shown a good potential but uptake by the law enforcement and legal community has been limited due to concerns about the admissibility of the new methods. As an introduction to the UGU2009 session "Forensic Provenancing using Geological and Geochemical Techniques" I will give an overview of the state of the art of forensic geology and the issues that concern the admissibility of geological forensic evidence. I will use examples from the NITECRIME and FIRMS networks, the EU TRACE project and other projects and literature to illustrate the important issues at hand.

  4. A geologic atlas of TIMS data

    NASA Technical Reports Server (NTRS)

    Abbott, Elsa

    1986-01-01

    In the three years since the first data were taken, it was well demonstrated that the Thermal Infrared Multispectral Scanner (TIMS), properly used, can be a most valuable tool for the geologist. Compilation of the TIMS data into a geological atlas was felt to be useful. Several data sets were extensively studied to establish TIMS as a geologic tool and to explore the optimum enhancement techniques. It was found that a decorrelation stretch of bands 1, 3, and 5 enhance the data to a form that is very useful and this enhancement will be used in the geologic atlas along with an accompanying geologic map and description. Many data sets are well published and familiar to TIMS users, but there are some sets that, for lack of time and funds, were not thoroughly studied or published. A short description of these least studied sets of data is presented. The images presented along with the many previously studied and published TIMS images constitute an enormously useful set of information for the geologist in the 8 to 10 micron range.

  5. Geologic Mapping of Arsia and Pavonis Montes

    NASA Technical Reports Server (NTRS)

    Williams, D. A.; Garry, W. B.; Bleacher, J. E.; Shean, D.; Greeley, R.

    2012-01-01

    We are funded by the NASA Mars Data Analysis Program (MDAP) to produce 1:1,000,000 scale geologic maps of Arsia Mons and Pavonis Mons, as well as conduct mapping of surrounding regions. In this abstract we discuss progress made during years 1 and 2 of the 4-year project.

  6. The Geology of Comet 19/P Borrelly

    NASA Technical Reports Server (NTRS)

    Britt, D. T.; Boice, D. C; Buratti, B. J.; Hicks, M. D.; Nelson, R. M.; Oberst, J.; Sandel, B. R.; Soderblom, L. A.; Stern, S. A.; Thomas, N.

    2002-01-01

    The Deep Space One spacecraft flew by Comet 19P/Borrelly on September 22, 2001 and returned a rich array of imagery with resolutions of up to 48 m/pixel. These images provide a window into the surface structure, processes, and geological history of a comet. Additional information is contained in the original extended abstract.

  7. Lunar Crustal Magnetism: Correlations with Geology

    NASA Technical Reports Server (NTRS)

    Halekas, J. S.; Mitchell, D. L.; Lin, R. P.; Frey, S.; Acuna, M. H.; Hood, L. L.; Binder, A. B.

    2001-01-01

    With Lunar Prospector reflectometry data we now have sufficient surface coverage to allow detailed comparisons between crustal magnetism and geology. We find substantial evidence that lunar magnetism is dominated by the effects of impact processes. Additional information is contained in the original extended abstract.

  8. Undergraduate Preparation for Graduate Work in Geology.

    ERIC Educational Resources Information Center

    Fetter, Charles W.

    1992-01-01

    Geoscience departments with graduate programs were surveyed to determine the courses required of entering graduate students. Most geologists consider the core curriculum to be that which is required or recommended by most graduate programs. In addition to geology courses, two semesters of calculus, physics, and chemistry were required by more than…

  9. US Geological Survey customers speak out

    USGS Publications Warehouse

    Gillespie, S.; Snyder, G.

    1995-01-01

    Provides results of a customer survey carried out in 1994 by the US Geological Survey. Uses of cartographic products are classified, as are application areas, accuracy satisfaction, media, Digital Line Graph requirements in update, and frequency of product use. USGS responses and plans for the future are noted. -M.Blakemore

  10. Iapetus: Tectonic structure and geologic history

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1991-01-01

    Many papers have been written about the surface of Iapetus, but most of these have discussed either the nature of the strongly contrasting light and dark materials or the cratering record. Little has been said about other geologic features on Iapetus, such as tectonic structures, which would provide constraints on Iapetus' thermal history. Most references have suggested that there is no conclusive evidence for any tectonic activity, even when thermal history studies indicate that there should be. However, a new study of Iapetus' surface involving the use of stereo pairs, an extensive tectonic network has been recognized. A few new observations concerning the craters and dark material were also made. Thus the geology and geologic history of Iapetus can be more fully outlined than before. The tectonic network is shown along with prominent craters and part of the dark material in the geologic/tectonic sketch map. The topology of crater rims and scarps are quite apparent and recognizable in the different image pairs. The heights and slopes of various features given are based on comparison with the depths of craters 50 to 100 km in diameter, which are assumed to have the same depths as craters of similar diameter on Rhea and Titania.

  11. Estimating the social value of geologic map information: A regulatory application

    USGS Publications Warehouse

    Bernknopf, R.L.; Brookshire, D.S.; McKee, M.; Soller, D.R.

    1997-01-01

    People frequently regard the landscape as part of a static system. The mountains and rivers that cross the landscape, and the bedrock that supports the surface, change little during the course of a lifetime. Society can alter the geologic history of an area and, in so doing, affect the occurrence and impact of environmental hazards. For example, changes in land use can induce changes in erosion, sedimentation, and ground-water supply. As the environmental system is changed by both natural processes and human activities, the system's capacity to respond to additional stresses also changes. Information such as geologic maps describes the physical world and is critical for identifying solutions to land use and environmental issues. In this paper, a method is developed for estimating the economic value of applying geologic map information to siting a waste disposal facility. An improvement in geologic map information is shown to have a net positive value to society. Such maps enable planners to make superior land management decisions.

  12. Geology and recognition criteria for uraniferous humate deposits, Grants Uranium Region, New Mexico. Final report

    SciTech Connect

    Adams, S.S.; Saucier, A.E.

    1981-01-01

    The geology of the uraniferous humate uranium deposits of the Grants Uranium Region, northwestern New Mexico, is summarized. The most important conclusions of this study are enumerated. Although the geologic characteristics of the uraniferous humate deposits of the Grants Uranium Region are obviously not common in the world, neither are they bizarre or coincidental. The source of the uranium in the deposits of the Grants Uranium Region is not known with certainty. The depositional environment of the host sediments was apparently the mid and distal portions of a wet alluvial fan system. The influence of structural control on the location and accumulation of the host sediments is now supported by considerable data. The host sediments possess numerous important characteristics which influenced the formation of uraniferous humate deposits. Ilmenite-magnetite distribution within potential host sandstones is believed to be the simplest and most useful regional alteration pattern related to this type of uranium deposit. A method is presented for organizing geologic observations into what is referred to as recognition criteria. The potential of the United States for new districts similar to the Grants Uranium Region is judged to be low based upon presently available geologic information. Continuing studies on uraniferous humate deposits are desirable in three particular areas.

  13. Goethe's Italian Journey and the geological landscape

    NASA Astrophysics Data System (ADS)

    Coratza, Paola; Panizza, Mario

    2015-04-01

    Over 220 years ago Johann Wolfgang von Goethe undertook a nearly two-years long and fascinating journey to Italy, a destination dreamed for a long time by the great German writer. During his journey from Alps to Sicily Goethe reflects on landscape, geology, morphology of "Il Bel Paese", sometimes providing detailed descriptions and acute observations concerning the great and enduring laws by which the earth and all within it are governed. He was an observer, with the eye of the geologist and landscape painter, as he himself stated, and therefore he had a 360 degree focus on all parts of the territory. From the Brenner Pass to Sicily, Goethe reflects on landscape, contrasting morphologies, the genesis of territories, providing detailed descriptions useful for reconstructing the conditions of the territory and crops of the late 18th century. His diary is a description of the impressions he received from the country and its people, mingled with reflections upon art, science and literature. Goethe studied mineralogical and geological phenomena and drew up notes on the life of the people, the climate and the plants. On various scientific occasions and, in particular, within the framework of the Italian Association "Geologia & Turismo", of the Working Group "Geomorphosites" of the International Association of Geomorphologists and the International Year of Planet Earth, the opportunity to re-examine Goethe's travels in Italy from a geological viewpoint was recognised. In the present paper an attempt was made to reproduce the geotourism itinerary ante litteram of the writer to Italy, one of the most important tourist destination worldwide, thanks to its rich cultural and natural heritage and the outstanding aesthetic qualities of the complex natural landscape. This project was essentially conceived with a twofold purpose. First of all, an attempt was made to reproduce the journey of a great writer, as an example of description of landscape perceived and described as

  14. Putting the geology back into Earth models

    NASA Astrophysics Data System (ADS)

    McCaffrey, K.; Imber, J.; Holdsworth, R.; Clegg, P.; de Paola, N.; Jones, R.; Hobbs, R.; Holliman, N.

    2005-12-01

    Geological architectures span at least 12 orders of magnitude length-scale from individual microstructures to lithospheric plates. Traditional paper-based geological mapping and fieldwork techniques have not been able to accurately capture the geospatial properties of mesoscale features in surface outcrops. In addition, geophysical imaging of the subsurface is poor at these length scales. This lack of fine-scale spatial precision has meant that the superbly detailed lithological units and structures we see in surface outcrops have not been integrated directly into predictive numerical and analogue models. As a result, models created to simulate mesoscale geology are currently not well calibrated to natural datasets and it is therefore difficult to demonstrate even partial confirmation of predictive, three dimensional (3D) models. This creates significant problems for industrial users interested in the extraction or storage of fluids in subsurface reservoirs, since accurate predictions of these processes rely critically on a complete 3D understanding of the subsurface mesoscale geology. Terrestrial laser scanners and Real Time Kinematic (RTK) GPS units are the principal tools used to capture digital data from surface outcrops. Automatic data collection involves scanning the outcrop surface with a laser to capture the topography with a cm-spaced grid of spatial coordinates in x,y and z. Using built-in digital cameras, the most recent laser scanners collect registered photographs that allow the software to colour the points to match the outcrop, and produce a photo-realistic 3D image. Laser scanning works best on cliff sections or in mines and quarries where the scanner can be placed directly in front of the outcrop. With RTK GPS data collection, any measurable attribute (surface dip, strike, lithology) can be recorded together with the spatial coordinates at a user-controlled sample spacing down to c. 5 cm. As the method is GPS-based, it works best on sub

  15. Environmental geology: Our professional public responsibility

    USGS Publications Warehouse

    Gerhard, L.C.; Brady, L.L.

    1999-01-01

    Conflicts between different interest groups for use of natural resources is one area where state geological surveys can provide assistance. A state geological survey working within the scientific constraints of specific issues can remain objective in its presentations and maintain the faith of both the conflicting interest groups and the public. One cannot vary from the objective view or you will quickly be criticized. Criticism can still occur from one side of a natural resource issue as your data might counter their views. However, the final decisions are almost always made in some legislators, or regulators, area of responsibility. The responsibility of the state geological survey is to provide the important data that will assist in making correct decisions. Should one party in the conflict become extreme in their demands, a potential compromise that is beneficial to both sides can be lost. In Kansas, the classical natural resource problem of resource/recreation in a populated area is presented as a case study. The state geological survey presented data on sand resources in the Kansas River and its valley in northeast Kansas. That information was important to both recreation and dredging interests where the political problem is a conflict of sand use as a construction material resource versus use of the alluvial river as an important recreation area, especially for canoeing. However, when a reasonable compromise was near completion in the Kansas Legislature one side, in a bold move to develop an advantage, ruined that potential for compromise.Conflicts between different interest groups for use of natural resources is one area where state geological surveys can provide assistance. A state geological survey working within the scientific constraints of specific issues can remain objective in its presentations and maintain the faith of both the conflicting interest groups and the public. In Kansas, the classical natural resource problem of resource/recreation in a

  16. The United States Geological Survey in Alaska: Accomplishments during 1977

    USGS Publications Warehouse

    Johnson, Kathleen M.

    1978-01-01

    United States Geological Survey projects in Alaska study a wide range of topics of economic and scientific interest. Work done in 1977 includes contributions to economic geology, regional geology, stratigraphy, engineering geology, hydrology, and marine geology. Many maps and reports covering various aspects of the geology and mineral and water resources of the State were published. In addition, the published 1:1,000,000-scale map of the State has been revised in two areas. A bibliography containing 263 reports on Alaska published in 1977 is included. (Woodard-USGS)

  17. Geology of the Yucca Mountain region

    USGS Publications Warehouse

    Stuckless, J.S.; O'Leary, D. W.

    2006-01-01

    Yucca Mountain has been proposed as the site for the nation's first geologic repository for high-level radioactive waste. This chapter provides the geologic framework for the Yucca Mountain region. The regional geologic units range in age from late Precambrian through Holocene, and these are described briefly. Yucca Mountain is composed dominantly of pyroclastic units that range in age from 11.4 to 15.2 Ma. The proposed repository would be constructed within the Topopah Spring Tuff, which is the lower of two major zoned and welded ash-flow tuffs within the Paintbrush Group. The two welded tuffs are separated by the partly to nonwelded Pah Canyon Tuff and Yucca Mountain Tuff, which together figure prominently in the hydrology of the unsaturated zone. The Quaternary deposits are primarily alluvial sediments with minor basaltic cinder cones and flows. Both have been studied extensively because of their importance in predicting the long-term performance of the proposed repository. Basaltic volcanism began ca. 10 Ma and continued as recently as ca. 80 ka with the eruption of cones and flows at Lathrop Wells, ???10 km south-southwest of Yucca Mountain. Geologic structure in the Yucca Mountain region is complex. During the latest Paleozoic and Mesozoic, strong compressional forces caused tight folding and thrust faulting. The present regional setting is one of extension, and normal faulting has been active from the Miocene through to the present. There are three major local tectonic domains: (1) Basin and Range, (2) Walker Lane, and (3) Inyo-Mono. Each domain has an effect on the stability of Yucca Mountain. ?? 2007 Geological Society of America. All rights reserved.

  18. Interpreting ground conditions from geologic maps

    USGS Publications Warehouse

    ,

    1949-01-01

    Intelligent planning for heavy construction, water supply, or other land utilization requires advance knowledge of ground conditions in the area. It is essential to know:the topography, that is, the configuration of the land surface;the geology and soils, that is, the deposits that compose the land and its weathered surface; andthe hydrology, that is, the occurrence of water whether under or on the ground.These elements usually are considered in planning land developments that involve much investment; detailed surveys generally are made of the topography, geology, soils, and hydrology at the site selected for development. Such detailed surveys are essential, but equally essential and often overlooked is the need for general surveys prior to site selection.Only if the general surveys have been made is it possible to know that a particular site is most suitable for the purpose and that no situations in the tributary areas that might affect the project have been overlooked. Moreover, the general regional relations must be known in order to properly interpret the geology, soils, and hydrology at a particular locality. In brief, both the general and the specific are needed in order to avoid costly mistakes either during or after development.The accompanying maps illustrate how a general geologic map can be used for interpreting grc .d conditions during a planning stage prior to site selection. The topographic and geologic maps, which provide the basic data, have been simplified from some existing ones. The interpretive sheets are intended to provide some examples of the kinds of information that trained persons can read from such basic maps.

  19. Mars geologic mapping program: Review and highlights

    NASA Astrophysics Data System (ADS)

    Scott, David H.

    1991-06-01

    The Mars Geologic Mapping (MGM) Program was introduced by NASA in 1987 as a new initiative in the Planetary Geology and Geophysics (PGG) Program. The overall purpose of the program is to support research on topical science problems that address specific questions. Among the objectives of the project are: (1) to produce highly detailed geologic maps that will greatly increase the knowledge of the materials and processes that have contributed to the evolutionary history of Mars; (2) to define areas of special interest for possible future investigation by planned missions (Mars Observer, Mars Sample Return); and (3) to maintain the interest of the planetary community in the development of new concepts and the re-evaluation of Martian geology as new data in usable form become available. Some interesting highlights of the geologic mapping indicate that multiple flood episodes occurred at different times during the Hesperian Period in both Kasei and Maja Valles. Studies of small channels in the Memnonia, Mangala, and Tharsis regions show that fluvial events appear to have occurred during the Amazonian Period at equatorial latitudes. Flood waters occurred during the Amazonian Period at equatorial latitudes. Flood waters from Mangala Valles may have seeped into surficial materials with the subsequent development of numerous sapping channels and debris flows; this suggests that the ancient highland terrain consists of relatively unconsolidated materials. Multiple layers were observed for the first time in the ridged plains lava flows covering large areas of Lunae Planum; some wrinkle ridges in this area are associated with grabens and collapse volcanic units at Hadriaca and Tyrrhena Paterae indicates that the units may have been emplaced by gravity-driven pyroclastic flows. Unlike the north polar layered deposits, those in the south polar region show no angular unconformities or evidence of faulting and folding. Water ice in the south polar layered deposits may be protected

  20. California and Saudi Arabia: geologic contrasts

    SciTech Connect

    Alexander, R.G. Jr.

    1984-09-01

    Assessing hydrocarbon futures in unexplored basins involves geology by analogy. Through 1978, approximately 265 fields were discovered in California containing 22 billion bbl of oil, 53% being in the 10 largest fields, ranging in size from 0.6 to 2.4 billion bbl. Through 1978, about 50 fields were found in Saudi Arabia containing 206 billion bbl of oil, 78% in the 10 largest fields, ranging in size from 7 to 83 billion bbl. The contrasts in field size distribution and in the total amount of oil present are explained by the dramatically different geology and geologic histories. California's surface geology is characterized by rare Precambrian, isolated Paleozoic, and widespread Mesozoic accreted terranes and intrusions, and by highly uplifted and depressed Tertiary sedimentary prisms bounded by widespread high-angle thrusting and strike-slip and normal faulting. Numerous families of medium to small anticlines and fault traps, commonly involving moderately dipping to overturned beds, have resulted from Tertiary tectonism, which segmented California dramatically. Saudi Arabia is characterized by a broad Precambrian shield area, flanked on the east by very long, gently dipping cuestas of Paleozoic and Mesozoic sediments, with an upper thin veneer of nearly flat Tertiary strata. Most structures involving the Mesozoic and Cenozoic are large, but gentle and unfaulted, representing a passive reaction of the sediments to underlying mild basement distortion and/or movement of Cambrian salt, all occurring while the arabian plate continued to subside and tip to the northeast. The contrasts between California and Saudi Arabia oil field and geology result from contrasting plate-tectonic settings and history.