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Sample records for geology wall-rock alteration

  1. 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.

  2. 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), sulfates (anhydrite) and halides (halite). The cooling calculations produce: (a) anhydrite, halite, sylvite; (b) Cu, Mo, Fe and Zn sulfides; (c) Mg fluoride at high temperature (> 370??C); (d) chlorides, fluorides and sulfates of Mn, Fe, Zn, Cu and Al at intermediate temperature (170-370??C); and (e) hydrated sulfates, liquid sulfur, crystalline sulfur, hydrated sulfuric acid and water at low temperature ( 0.41 (> 628??C). This is followed by precipitation of sulfates of Fe, Cu, Pb, Zn and Al at lg/a ratios between 0.41 and -0.4 (628-178??C). At a lg/r ratio of < - 0.4 (178??C), anhydrous sulfates are replaced by their hydrated forms and hygroscopic sulfuric acid forms. At these low g/a ratios, hydrated sulfuric acid becomes the dominant phase in the system. Comparison of the thermochemical modeling results with the natural samples suggests that the alteration assemblages include: (1) minerals that precipitate from direct cooling of the volcanic gas; (2) phases that form by volcanic gases mixing with air; and (3) phases that form by volcanic gas-air-rock reaction. A complex interplay of the three processes produces the observed mineral zoning. Another implication of the numerical simulation results is that most of the observed incrustation and sublimate minerals apparently formed below 700??C.

  3. Textures, paragenesis and wall-rock alteration of lode-gold deposits in the Charters Towers district, north Queensland: implications for the conditions of ore formation

    NASA Astrophysics Data System (ADS)

    Kreuzer, Oliver P.

    2006-01-01

    Ore deposits of the Charters Towers Goldfield (CTGF) are mainly hosted by fault-fill veins. Extensional (8% of all veins) and stockwork-like (3%) veins are less common and of little economic significance. Crosscutting relationships and published structural and geochronological data indicate a Late Silurian to Early Devonian timing of gold mineralization, coincident with regional shortening (D4) and I-type magmatism. Paragenetic relationships, which are uniform in veins everywhere within the CTGF, suggest that vein formation commenced with the deposition of large volumes of buck quartz (stage I), followed by buck and comb quartz, and significant pyrite and arsenopyrite precipitation (stage II). Gold was introduced during stage III, after earlier sphalerite and coincident with galena and chalcopyrite. Narrow, discontinuous calcite veins of stage IV mark the waning of gold-related hydrothermal activity or a later unrelated episode. Ore zones within the veins are everywhere composed of comb and/or gray quartz, calcite and/or ankerite and bands or clusters of fractured pyrite that are spatially associated with galena, sphalerite or chalcopyrite. Low-grade or barren vein sections, on the other hand, are mainly composed of milky buck quartz with little evidence for modification, overprinting or interaction with later fluids. Gold-related hydrothermal wall-rock alteration is symmetrically zoned, displaying proximal sericite-ankerite and distal epidote-chlorite-hematite assemblages that may be taken to imply wall-rock interaction with near neutral fluids (pH 5-6). Isocon plots assuming immobile Al, P, Ti, Y and Zr consistently indicate As, K, Pb, S and Zn enrichment and Na, Si and Sr depletion in altered wall-rock specimens relative to the least altered rocks. Alteration assemblages, quartz textures, fault rocks and published fluid inclusion and stable isotope data imply that the veins were formed under conditions of episodic fluid overpressuring (0.9-3.8 kbar), at a depth of 7 km and a temperature of 310C. The published fluid inclusion data also imply that gold precipitation may have been brought about by fluid mixing. However, physi- and chemisorption of gold complexes onto sulfide surfaces may have been important depositional processes and controls on gold enrichment at the millimeter to centimeter scale, given that most gold particles are attached to the surfaces of pyrite crystals of stage II or to etch-pits and fracture surfaces within the earlier pyrite.

  4. [The application of spectral geological profile in the alteration mapping].

    PubMed

    Li, Qing-Ting; Lin, Qi-Zhong; Zhang, Bing; Lu, Lin-Lin

    2012-07-01

    Geological section can help validating and understanding of the alteration information which is extracted from remote sensing images. In the paper, the concept of spectral geological profile was introduced based on the principle of geological section and the method of spectral information extraction. The spectral profile can realize the storage and vision of spectra along the geological profile, but the spectral geological spectral profile includes more information besides the information of spectral profile. The main object of spectral geological spectral profile is to obtain the distribution of alteration types and content of minerals along the profile which can be extracted from spectra measured by field spectrometer, especially for the spatial distribution and mode of alteration association. Technical method and work flow of alteration information extraction was studied for the spectral geological profile. The spectral geological profile was set up using the ground reflectance spectra and the alteration information was extracted from the remote sensing image with the help of typical spectra geological profile. At last the meaning and effect of the spectral geological profile was discussed. PMID:23016344

  5. 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

    Bhlke, 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

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

    NASA Astrophysics Data System (ADS)

    Ait Chaou, Abdelouahed; Abdelouas, Abdesselam; Karakurt, Gkhan; 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.

  7. 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.

  8. Foam flow through a transparent rough-walled rock fracture

    SciTech Connect

    Kovscek, A.; Tretheway, D.; Radke, C.

    1995-07-01

    This paper presents an experimental study of nitrogen, water, and aqueous foam flow through a transparent replica of a natural rough-walled rock fracture with a hydraulic aperture of roughly 30 {mu}m. It is established that single-phase flow of both nitrogen and water is well described by analogy to flow between parallel plates. Inertial effects caused by fracture roughness become important in single-phase flow as the Reynolds number approaches 1. Foam exhibits effective control of gas mobility. Foam flow resistances are approximately 10 to 20 times greater than those of nitrogen over foam qualities spanning from 0.60 to 0.99 indicating effective gas-mobility control. Because previous studies of foam flow have focused mainly upon unfractured porous media, little information is available about foam flow mechanisms in fractured media. The transparency of the fracture allowed flow visualization and demonstrated that foam rheology in fractured media depends upon bubble shape and size. Changes in flow behavior are directly tied to transitions in bubble morphology.

  9. 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 volatile-fluid phases, which have encountered a local hydrologically active fault. The explosions were inadequate in mechanical energy release (72% of a mine production blast) to eject material from the pipe, and the pipe may not have breached surface. The next stage of fragmentation is interpreted to have been an upward-moving collapse of the pre-conditioned hanging wall of a subterranean volcanic excavation. This would explain the mega-scale layering across the width of the breccia pipe. It must be questioned whether the preserved K08 architecture represents early pipe development in general, or is a special case of a late pipe geometry modification process. Previous literature describes sidewall and hanging wall caving processes elsewhere in the Venetia cluster and other kimberlites world wide. A requirement for emplacement models that include upward pipe growth processes is the availability of space (mass deficit at depth) into which the caving and/or dilating breccia can expand. It is possible that K08 might be connected to adjacent K02 at a depth somewhere below 400m, which would explain the presence of volcaniclastic kimberlite at depth within the K08 pipe. K08 is likely an incomplete ancillary sideward development to K02. The latest stage of brecciation is quantified through an observed evolution in the fractal dimension of the PSD. It is interpreted to be due to complex adjustments in volume in the pipe causing shearing and re-fragmentation of the breccia.

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

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

    Interaction of magma with wall rock is an important process in igneous petrology, but the mechanisms by which interactions occur are poorly known. The western outer granodiorite of the Cretaceous Tuolumne Intrusive Suite of Yosemite National Park, California, intruded a variety of metasedimentary and igneous wall rocks at 93.1 Ma. The May Lake metamorphic screen is a metasedimentary remnant whose contact zone exhibits a variety of interaction phenomena including xenolith incorporation, disaggregation, and partial melting. The chemical contrast of these metasedimentary rocks with the invading pluton provides an excellent measure of pluton/wall rock interactions. Wall rock xenoliths (mostly pelitic quartzite) are predominantly located in an elongate horizon surrounded by a hybridized fine-grained granodiorite. Initial Sr and Nd isotopic ratios of the hybridized granodiorite indicate significant local incorporation of crustal material. Major- and trace-element geochemical data indicate that contamination of the granodiorite occurred via selective assimilation of both high-K and low-K, high-silica partial melts derived from pelitic quartzite. Although the hybridized granodiorite shows significant amounts of contamination, adjacent to xenoliths the proportion of contamination is undetectable more than a meter away. These results indicate that the chemical and isotopic variability of the Tuolumne Intrusive Suite is not caused by magma contamination via in situ wall rock assimilation.

  11. 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.

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

    USGS Publications Warehouse

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

    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.

  13. A new Method in the displaying of Deep Contact relationships of an intrusive body with the wall rocks: Ground Penetrating Radar (GPR) Buzlukdagi Syenitoids (Kirsehir-Turkey)

    NASA Astrophysics Data System (ADS)

    Deniz, K.; Kadioglu, S.; Kadioglu, Y. K.

    2012-04-01

    Ground penetrating radar (GPR) method can be used in the geological studies for identifying the rock boundaries, joints and trace fractures. The research area comprises a part of alkaline igneous rocks (Buzlukdagi) at Central Anatolia, Turkey. These intrusive rocks are exposed as a small alkaline pluton which intruded into the metamorphic rocks in the composition of foid bearing syenitoid. The wall rock of the intrusive body mainly composed of migmatite and marble as a result of contact metamorphism of the dentritic and limestone rock units. The alkaline intrusive rocks have fine grain with holocrystalline texture at the contact zone. The wall rocks have a clear lineation with the melting signature in the form of migmatite. Marble rock blocks can be observed within the intrusive body at the outer zone of the contact. Fluorite bearing hydrothermal products can be seen along the fault and discontinuity zones within the alkaline unit in the studying area. Accordingly, joints and the fracture zones are very important for the mine researches in the region. This study presents the results of an application of GPR method for determination of the rock boundaries, joints and fractures within the studying area. In this study, RAMAC CU II equipment was used with 250 MHz shielded antenna to observe the lithological boundaries and fractures of the study area. The GPR measurements were taken on eight profiles with different lengths and different measurement time in order to identify the discontinuities according to the increasing depth. Time axis was transformed to the depth axis according to the determined 0.11m/ns of electromagnetic wave velocity as a result of velocity analysis. Generally the geological discontinuities could be seen until 10-14m in depth on radargrams of the profiles, while the radargram of the profile 3, which had 115m length and 900 ns of measurement time, could show them until 48m in depth. The discontinuity and xenoliths of the wall rocks are observed as various length and width within the intrusive body. Keywords: Ground Penetrating Radar (GPR), Marble xenolith, Fluorite, Migmatite.

  14. Geology

    SciTech Connect

    Reidel, Stephen P.

    2008-01-17

    This chapter summarizes the geology of the single-shell tank (SST) farms in the context of the region’s geologic history. This chapter is based on the information in the geology data package for the SST waste management areas and SST RFI Appendix E, which builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.

  15. Geological context of water-altered minerals in Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Chojnacki, Matthew; Hynek, Brian M.

    2008-12-01

    Greater than 15,000 km2 of the layered deposits within Valles Marineris are associated with water-altered minerals, yet their origin and history of alteration remain a mystery. There are numerous competing hypotheses for the formation of the interior layered deposits including aeolian, lacustrine, and volcanic. Recent orbiter spectroscopic data have indicated that water has played a role in their geological history. Thermal Emission Spectrometer (TES) measurements have revealed significant crystalline hematite-bearing deposits within Valles Marineris, typically related to interior layered deposits. These hematite deposits, found with a wide range of albedo values, are associated with relatively steep bedrock exposures but can also be seen downslope on flat surfaces where they may be a lag deposit. More recently, Observatoire la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) data have shown hydrated sulfates covering more than 13,000 km2 area of Valles Marineris. Sulfates are found in numerous topographic settings and geological units, but are typically located along the flanks of interior layered deposits and nearby low-lying floor units. Here we study the detailed morphologies of hematite and sulfate-bearing units such as mantled wall units, mass-wasting blocky deposits, massive floor deposits, and tectonically altered floor units. All of these terrains have diverse erosional styles and varied crater populations. In both hematite- and sulfate-bearing units, occasionally found in conjunction with one another, formation processes require contributions from water. The results indicate a wide range of diversity within an individual mineral class, between mineral classes, and also among morphological types. The diversity of geological settings and properties suggest that any single, unified formation mechanism is improbable.

  16. 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.

  17. 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

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

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  19. On Two-Phase Relative Permeability and Capillary Pressure ofRough-Walled Rock Fractures

    SciTech Connect

    Pruess , K.; Tsang, Y.W.

    1989-09-01

    This paper presents a conceptual and numerical model of multiphase flow in fractures. The void space of real rough-walled rock fractures is conceptualized as a two-dimensional heterogeneous porous medium, characterized by aperture as a function of position in the fracture plane. Portions of a fracture are occupied by wetting and nonwetting phase, respectively, according to local capillary pressure and accessibility criteria. Phase occupancy and permeability are derived by assuming a parallel-plate approximation for suitably small subregions in the fracture plane. For log-normal aperture distributions, a simple approximation to fracture capillary pressure is obtained in closed form; it is found to resemble the typical shape of Leverett's j-function. Wetting and non-wetting phase relative permeabilities are calculated by numerically simulating single phase flows separately in the wetted and non-wetted pore spaces. Illustrative examples indicate that relative permeabilities depend sensitively on the nature and range of spatial correlation between apertures. It is also observed that interference between fluid phases flowing in a fracture tends to be strong, with the sum of wetting and nonwetting phase relative permeabilities being considerably less than 1 at intermediate saturations.

  20. 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 produce the near linear or sometimes coiled tubes. Instead, we envision the activity of hyphae-like organelles or filaments, that may radiate out from a host body located in direct contact with circulating water, possibly penetrating a biofilm and entering/drilling into the fresh glass. Such microdrilling is well described in soils, where hyphae can slowly drill into silicates, in a process that takes about 1000 years to become visible as tunnels.

  1. 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

  2. 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.

  3. The fossil hydrothermal system of Saint Martin, Lesser Antilles: geology and lateral distribution of alterations

    NASA Astrophysics Data System (ADS)

    Beaufort, D.; Westercamp, D.; Legendre, O.; Meunier, A.

    1990-04-01

    The fossil geothermal system of Saint Martin, Lesser Antilles, was generated by an intrusion of quartz-diorite of Oligocene age into Eocene volcano-sedimentary host rocks. Adjacent to the pluton, the alteration pattern crops out continuously in the Fort Hill-Kool Bay area over a distance of 4 km. The lithology of the altered host rocks is the following: (1) alternating marls, limestones and minor hyaloclastite (Lower Eocene); (2) hyaloclastite and andesitic lava flows (Middle Eocene); (3) regularly bedded fine-grained hyaloclastite (Upper Eocene). On the basis of alteration petrography, chemistry and fluid-inclusion study, three alteration events have been distinguished: (1) High-temperature event (510 > T > 350C) accompanied by fluids with salinity higher than 35 wt.% NaCl-eq), mainly represented by tourmaline, quartz, magnetite, orthoclase, apatite and sulfide veins, occurring at the periphery of the pluton and along distal regional faults. (2) Moderate temperature event occurring as veins and pervasive alteration. Veins containing quartz, phengite, pyrite and minor dickite or chlorite ( T = 300C, very low salinity) are superimposed on the early high-temperature veins. Pervasive alteration affected large concentric zones: the inner zone (3 km width) shows an assemblage of epidote, quartz, actinolite magnetite at the periphery of the pluton and epidote, quartz and chlorite farther away. The outer zone (1 km width) shows calcite and mixed-layer illite/smectite (I/S) with ordering type R3 and chlorite/smectite (C/S). Fluid inclusions indicate that salinity and temperature decrease outward from the intrusion during the moderate-temperature pervasive alteration event (respectively from 320 to 140C and from 30 to 5 wt.% NaCl-eq). (3) Low-temperature event ( T < 50C) showing calcite, mixed-layer I/S (RO), chalcedonite or baryte in late disseminated veins. This lateral distribution of alteration is very similar to alteration zoning observed in porphyry ore environment or in active deep geothermal systems as Baca (Valles caldera). It shows contrast between zones of fracture permeability which controlled active flow in the system and large zones where pervasive alteration occurred in an inactive flow regime and can be included with metamorphic process. Phyllic alteration seems a good indicator of the active flow paths in the system of Saint Martin. The alteration pattern in Saint Martin is considered to represent the roots of a deep geothermal system (porphyry ore system?) of Oligocene age, actually eroded.

  4. 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.

  5. 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.

  6. Tail shortening with developing eddies in a rough-walled rock fracture

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyun; Yeo, In Wook; Lee, Kang-Kun; Detwiler, Russell L.

    2015-08-01

    Understanding fluid flow and solute transport in rough-walled fractures is important in many problems such as geological storage of CO2 and siting of radioactive waste repositories. The first microscopic observation of fluid flow and solute transport through a rough-walled fracture was made to assess the evolution of eddies and their effect on non-Fickian tailing. A noteworthy phenomenon was observed that as the eddy grew, the particles were initially caught in and swirled around within eddies, and then cast back into main flow channel, which reduced tailing. This differs from the conventional conceptual model, which presumes a distinct separation between mobile and immobile zones. Fluid flow and solute transport modeling within the 3-D fracture confirmed tail shortening due to mass transfer by advective paths between the eddies and the main flow channel, as opposed to previous 2-D numerical studies that showed increased tailing with growing eddies.

  7. Accounting for geochemical alterations of caprock fracture permeability in basin-scale models of leakage from geologic CO2 reservoirs

    NASA Astrophysics Data System (ADS)

    Guo, B.; Fitts, J. P.; Dobossy, M.; Bielicki, J. M.; Peters, C. A.

    2012-12-01

    Climate mitigation, public acceptance and energy, markets demand that the potential CO2 leakage rates from geologic storage reservoirs are predicted to be low and are known to a high level of certainty. Current approaches to predict CO2 leakage rates assume constant permeability of leakage pathways (e.g., wellbores, faults, fractures). A reactive transport model was developed to account for geochemical alterations that result in permeability evolution of leakage pathways. The one-dimensional reactive transport model was coupled with the basin-scale Estimating Leakage Semi-Analytical (ELSA) model to simulate CO2 and brine leakage through vertical caprock pathways for different CO2 storage reservoir sites and injection scenarios within the Mt. Simon and St. Peter sandstone formations of the Michigan basin. Mineral dissolution in the numerical reactive transport model expands leakage pathways and increases permeability as a result of calcite dissolution by reactions driven by CO2-acidified brine. A geochemical model compared kinetic and equilibrium treatments of calcite dissolution within each grid block for each time step. For a single fracture, we investigated the effect of the reactions on leakage by performing sensitivity analyses of fracture geometry, CO2 concentration, calcite abundance, initial permeability, and pressure gradient. Assuming that calcite dissolution reaches equilibrium at each time step produces unrealistic scenarios of buffering and permeability evolution within fractures. Therefore, the reactive transport model with a kinetic treatment of calcite dissolution was coupled to the ELSA model and used to compare brine and CO2 leakage rates at a variety of potential geologic storage sites within the Michigan basin. The results are used to construct maps based on the susceptibility to geochemically driven increases in leakage rates. These maps should provide useful and easily communicated inputs into decision-making processes for siting geologic CO2 storage sites.

  8. Wall-rock metasomatism of carbonaceous terrigenous rocks in the Lena gold district

    NASA Astrophysics Data System (ADS)

    Rusinov, V. L.; Rusinova, O. V.; Kryazhev, S. G.; Shchegol'Kov, Yu. V.; Alysheva, E. I.; Borisovsky, S. E.

    2008-02-01

    The Lena gold district is situated in the fold-and-shear belt of the southern framework of the Siberian Platform. The gold deposits are hosted in the Riphean-Vendian Khomolkho and Aunakit formations, revealing the strict control of ore mineralization by folding and shearing. The microstructure of metasomatically altered ore-bearing carbonaceous sedimentary rocks at the Sukhoi Log, Golets Vysochaishy, and Verninsky deposits (the latter includes the Pervenets vein zone) testifies to parallelism in the development of shearing, foliation, and ore-forming metasomatism. The local pressure gradients are marked by removal of silica from pressured zones into opened cleavage fractures and pockets. Two metasomatic stages are recognized: (1) early sodic metasomatism, which is characterized by the assemblage of magnesian siderite and paragonite, and (2) late potassic metasomatism, with formation of muscovite in association with sideroplesite and ankerite. The rocks altered at the early stage are distinguished by elevated Ni, Cr, and probably PGE contents. The second stage, close in age to the emplacement of Hercynian granitic plutons, was accompanied by the gain of chalcophile metals and deposition of the bulk of gold. In mineral composition, the metasomatic rocks are close to beresites, but the alteration differed in somewhat elevated alkalinity, so that microveinlets of albite and potassium feldspar occur in the ore zone together with muscovite. The ratio of modal muscovite to paragonite contents in orebodies is substantially higher than in the surrounding metasomatized rocks. This ratio directly depends on the degree of rock permeability and the intensity of the flow of ore-forming solutions. Carbonaceous matter (CM) in the ore zone underwent reworking and redeposition. CM is graphitized to a lesser extent than in the rocks affected by regional metamorphism. The spatial distribution of CM containing nitro and amino groups indicates more oxidizing conditions in the zone of ore deposition than at a distance from this zone. The temperature of metasomatic processes estimated from the muscovite, muscovite-paragonite, and chlorite mineral thermometers and fluid inclusions in quartz was 300-350C at a pressure of about 1 kbar. The S, O, and C isotopic compositions of ore-forming fluids that pertain to the second stage of metasomatism (?34S= +8.5, ?18O = +10, and ?13C= -11 to -18) indicate their crustal origin. The generally similar conditions and products of the ore-forming metasomatic process at the giant Sukhoi Log deposit and at the small Golets Vysochaishy deposit are combined with some differences. The formation of the described deposits was related to the deep convection of fluids along shear zones followed by more local flows of postmagmatic solutions derived from the emplaced granitic magma.

  9. Wall-rock control of cortain pitchblende deposits in Golden Gate Canyon, Jefferson County, Colorado

    USGS Publications Warehouse

    Adams, John W.; Stugard, Frederick, Jr.

    1954-01-01

    Carbonate veins cutting pre-Cambrian metamorphic rocks in Golden Gate Canyon contain pitchblende and base-metal sulfides. The veins occupy extensive faults of Laramide age but normally contain pitchblende only where the cut hornblende gneiss. At the Union Pacific prospect, which was studied in detail, pitchblende, hermatite, and some ankerite formed in advance of sulfides, except possibly for minor pyrite. Base-metal sulfides and the bulk of ankerite-calcite vein-filling were deposited after the pitchblende. Chemical analyses show a high ferrous iron content in the hornblende gneiss in contrast to low ferrous iron in the adjacent biotite gneiss. It is hypothesized that ferrous iron released by alteration of hornblende was partly oxidized to hematite by the ore-bearing solutions and, contemporaneously, uranium was reduced and deposited as pitchblende. In other veins, biotite or iron sulfides may have been similarly effective in precipitating pitchblende. Apparently both the ferrous ion and the sulfide ion can serve as reducing agents and control pitchblende deposition. It is suggested that conditions particularly favorable for uranium deposition are present where uranium-bearing solutions had access to rocks rich in ferrous iron or pre-existing sulfides.

  10. 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.

  11. Two-phase flow visualization and relative permeability measurement in transparent replicas of rough-walled rock fractures

    SciTech Connect

    Persoff, P.; Pruess, K.; Myer, L.

    1991-01-01

    Understanding and quantifying multi-phase flow in fractures is important for mathematical and numerical simulation of geothermal reservoirs, nuclear waste repositories, and petroleum reservoirs. While the cubic law for single-phase flow has been well established for parallel-plate fractures theoretically and experimentally, no reliable measurements of multi-phase flow in fractures have been reported. This work reports the design and fabrication of an apparatus for visualization of two-phase flow and for measurement of gas-liquid relative permeability in realistic rough-walled rock fractures. A transparent replica of a natural rock fracture from a core specimen is fabricated by molding and casting in clear epoxy. Simultaneous flow of gas and liquid with control of capillary pressure at inlet and outlet is achieved with the Hassler sandwich'' design: liquid is injected to the fracture through a porous block, while gas is injected directly to the edge of the fracture through channels in the porous block. A similar arrangement maintains capillary separation of the two phases at the outlet. Pressure drops in each phase across the fracture, and capillary pressures at the inlet and outlet, are controlled by means of pumps and needle valves, and are measured by differential and absolute pressure transducers. The clear epoxy cast of the natural fracture preserves the geometry of the fracture and permits visual observation of phase distributions. The fracture aperture distribution can be estimated by filling the fracture with a dyed liquid, and making pointwise measurements of the intensity of transmitted light.

  12. Two-phase flow visualization and relative permeability measurement in transparent replicas of rough-walled rock fractures

    SciTech Connect

    Persoff, P.; Pruess, K.; Myer, L.

    1991-01-01

    Understanding and quantifying multi-phase flow in fractures is important for mathematical and numerical simulation of geothermal reservoirs, nuclear waste repositories, and petroleum reservoirs. While the cubic law for single-phase flow has been well established for parallel-plate fractures theoretically and experimentally, no reliable measurements of multi-phase flow in fractures have been reported. This work reports the design and fabrication of an apparatus for visualization of two-phase flow and for measurement of gas-liquid relative permeability in realistic rough-walled rock fractures. A transparent replica of a natural rock fracture from a core specimen is fabricated by molding and casting in clear epoxy. Simultaneous flow of gas and liquid with control of capillary pressure at inlet and outlet is achieved with the Hassler ''sandwich'' design: liquid is injected to the fracture through a porous block, while gas is injected directly to the edge of the fracture through channels in the porous block. A similar arrangement maintains capillary separation of the two phases at the outlet. Pressure drops in each phase across the fracture, and capillary pressures at the inlet and outlet, are controlled by means of pumps and needle valves, and are measured by differential and absolute pressure transducers. The clear epoxy cast of the natural fracture preserves the geometry of the fracture and permits visual observation of phase distributions. The fracture aperture distribution can be estimated by filling the fracture with a dyed liquid, and making pointwise measurements of the intensity of transmitted light. A set of two-phase flow experiments has been performed which has proven the viability of the basic experimental design, while also suggesting further improvements in the apparatus. Preliminary measurements are presented for single-phase permeability to liquid, and for relative permeabilities in simultaneous flow of liquid and gas.

  13. 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.

  14. 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.

  15. 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 volumetrically small heterogeneities within the heterogeneous source. We hypothesize that rising melt will cause rapid and limited flux-melting in adjacent wall-rock as long as the melt+wall-rock system generates a larger equilibrium melt volume than the initial local melt volume, and that the preferred amount of local flux-melting is equal to the maximum amount of potential local flux-melting. (e.g., the volume fraction of wall-rock that interacts with melt is the fraction that maximizes the productivity of flux-melting.) As local flux-melting consumes latent-heat, wall-rock flux melting also reduces shallower melt-productivity of the assemblage. Since the hydrogen diffusion rate is too low to equilibrate the water contents of veins and surrounding matrix within the melting zone, dry and wet lithologies can coexist next to each other. Considering the dehydration related increase in viscosity for each lithology, the aggregate viscosity remains low until the last (most depleted) major lithology starts to melt -- e.g. until the most refractory harzburgites cross their wet solidus.

  16. 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 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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

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

  18. 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

    The Noachian terrain west of the Isidis basin hosts a diverse collection of alteration minerals in rocks comprising varied geomorphic units within a 100,000 km2 region in and near the Nili Fossae. Prior investigations in this region by the Observatoire pour l'Min??ralogie, l'Eau, les Glaces, et l'Activit?? (OMEGA) instrument on Mars Express revealed large exposures of both mafic minerals and iron magnesium phyllosilicates in stratigraphic context. Expanding on the discoveries of OMEGA, the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter (MRO) has found more spatially widespread and mineralogically diverse alteration minerals than previously realized, which represent multiple aqueous environments. Using CRISM near-infrared spectral data, we detail the basis for identification of iron and magnesium smectites (including both nontronite and more Mg-rich varieties), chlorite, prehnite, serpentine, kaolinite, potassium mica (illite or muscovite), hydrated (opaline) silica, the sodium zeolite analcime, and magnesium carbonate. The detection of serpentine and analcime on Mars is reported here for the first time. We detail the geomorphic context of these minerals using data from high-resolution imagers onboard MRO in conjunction with CRISM. We find that the distribution of alteration minerals is not homogeneous; rather, they occur in provinces with distinctive assemblages of alteration minerals. Key findings are (1) a distinctive stratigraphy, in and around the Nili Fossae, of kaolinite and magnesium carbonate in bedrock units always overlying Fe/Mg smectites and (2) evidence for mineral phases and assemblages indicative of low-grade metamorphic or hydrothermal aqueous alteration in cratered terrains. The alteration minerals around the Nili Fossae are more typical of those resulting from neutral to alkaline conditions rather than acidic conditions, which appear to have dominated much of Mars. Moreover, the mineralogic 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.

  19. 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 ?REE contents, strong REE fractionation, and the absence of significant Eu and Ce anomalies. High-grade iron ores in the G2 show similar ?18OV-SMOW values for magnetite, lower ?18OV-SMOW values for quartz and higher ?34SV-CDT values for pyrite when compared to the BIFs, whereas the QW shows lower ?18OV-SMOW values for magnetite, similar ?18OV-SMOW values for quartz and similar ?34SV-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.

  20. Altered volcanic ash partings in Wasatch Formation coal beds of the northern Powder River basin: composition and geologic applications

    USGS Publications Warehouse

    Bohor, Bruce Forbes; Phillips, Richard E.; Pollastro, Richard M.

    1979-01-01

    In contrast to the coal-bearing rocks of the Appalachian and Eastern Interior Basins, those of the northern Powder River Basin exhibit more complex stratigraphic and facies relationships, and regional correlations of coal beds are, therefore, more difficult to establish. Recently, however, several coal beds in the Powder River Basin, as well as coal beds in several other coal basins of the Rocky Mountain region, have been found to contain thin but persist·ent layers. of altered volcanic ash described as kaolinitic bentonites (Bohor, 1976, 1977, 1978, Bohor and others, 1976, 1978, Bohor and Pillmore, 1976). These layers serve as isochronous marker horizons which aid in correlating coal beds over broad areas.

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

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  2. 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.

  3. Dynamics of changes in the physical characteristics of a hydrothermally altered geological section according to nonisothermal physicochemical simulation (the Mutnovsky Volcano)

    NASA Astrophysics Data System (ADS)

    Bessonova, E. P.; Gora, M. P.; Shevko, A. Ya.; Chudnenko, K. V.; Cherepanova, V. K.

    2011-06-01

    The paper presents the results of numerical simulation of a subaerial volcanic hydrothermal system. The model is based on the factual data on the rock composition and the geological structure of the Mutnovsky Volcano. We develop a new approach to construct the numerical model of a volcanic hydrothermal system. According to this approach, at each step of the calculation, for each point of the spatiotemporal domain, the thermophysical properties are determined; further, these properties are used in the calculation of the equilibrium state of the system. This procedure allows us to take into account the dynamic changes in the T-P conditions in the cross section and the migration of the phase boundaries. As well, using this approach, we can pass from "conditional" time in the description of the evolution of the magmagenic fluid system to the "virtually dimensional time" of the development of the simulated ore-magmatic system, from the onset of melt crystallization in the intrusive chamber up to the termination of the retrograde boiling of the melt. The simulation shows that, depending on the structure of the lower part of the section, contrasting hydrothermal systems can develop in the originally homogeneous medium. The relation between the temperature, and, therefore, phase composition of the fluid and the features of the hydrothermal alteration in volcanic rocks is demonstrated. Among other questions, in the present paper we discuss the changes in the density and magnetic properties of the volcanogenic section.

  4. 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 preparation by a member of the Uranium Research and Resource Section, U.S. Geological Survey, was done on behalf of the Division of Raw Materials, U.S. Atomic Energy Commission. The report is based on both published and unpublished information collected principally by personnel of the U.S. Geological Survey, the U.S. Atomic Energy Commission or its predecessor organization, the Manhattan Engineer District, and to a lesser extent by staff members of other Federal or State agencies and by geologists in private industry. Information concerning foreign uranium-bearing vein deposits has been extracted almost exclusively from published reports; references to these and other data are included at appropriate places.

  5. 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)

  6. 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)

  7. Environmental Geology

    ERIC Educational Resources Information Center

    Dunn, James R.

    1977-01-01

    Discusses ways that geologic techniques can be used to help evaluate our environment, make economic realities and environmental requirements more compatible, and expand the use of geology in environmental analyses. (MLH)

  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 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.

  10. Environmental Geology

    ERIC Educational Resources Information Center

    Passero, Richard N.

    1978-01-01

    1977 was a year of continued and expanding efforts in the application of the geosciences to land-use planning, especially as they relate to geologic hazards, and elucidating the role of geology in public policy. The work of environmental geological programs is reviewed. (Author/MA)

  11. 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)

  12. Alteration of ocean crust provides a strong temperature dependent feedback on the geological carbon cycle and is a primary driver of the Sr-isotopic composition of seawater

    NASA Astrophysics Data System (ADS)

    Coogan, Laurence A.; Dosso, Stan E.

    2015-04-01

    On geological timescales there is a temperature dependent feedback that means that increased degassing of CO2 into the atmosphere leads to increased CO2 drawdown into rocks stabilizing Earth's climate. It is widely considered that this thermostat largely comes from continental chemical weathering. An alternative, or additional, feedback comes from dissolution of seafloor basalt in low-temperature (tens of C), off-axis, hydrothermal systems. Carbonate minerals precipitated in these systems provide strong evidence that increased bottom water temperature (traced by their O-isotopic compositions) leads to increased basalt dissolution (traced by their Sr-isotopic compositions). Inversion of a simple probabilistic model of fluid-rock interaction allows us to determine the apparent activation energy of rock dissolution in these systems. The high value we find (92 7 kJmol-1) indicates a strong temperature dependence of rock dissolution. Because deep-ocean temperature is sensitive to global climate, and the fluid temperature in the upper oceanic crust is strongly influenced by bottom water temperature, increased global temperature must lead to increased basalt dissolution. In turn, through the generation of alkalinity by rock dissolution, this leads to a negative feedback on planetary warming; i.e. off-axis, hydrothermal systems play an important role in the planetary thermostat. Changes in the extent of rock dissolution, due to changes in bottom water temperature, also lead to changes in the flux of unradiogenic Sr into the ocean. The decreased flux of unradiogenic Sr into the ocean due to the cooling of ocean bottom water over the last 35 Myr is sufficient to explain most of the increase in seawater 87Sr/86Sr over this time.

  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. Archeological Geology.

    ERIC Educational Resources Information Center

    Gifford, John A.

    1983-01-01

    Discusses some of the publication outlets, from international to relatively esoteric, used in archeological geology and comments on a possible future trend in publication of archeological-geology research. Publication outlets considered include books (including those published by university presses), journals, and government publications.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. Environmental Geology

    ERIC Educational Resources Information Center

    Everett, A. Gordon

    1972-01-01

    Briefly summarizes the major applications, during 1971, of geology to environmental problems in the United States and mentions some of the related literature from professional meetings and from other publications. (PR)

  1. Geology, summary

    NASA Technical Reports Server (NTRS)

    Sabins, F. F., Jr.

    1975-01-01

    Trends in geologic application of remote sensing are identified. These trends are as follows: (1) increased applications of orbital imagery in fields such as engineering and environmental geology - some specific applications include recognition of active earthquake faults, site location for nuclear powerplants, and recognition of landslide hazards; (2) utilization of remote sensing by industry, especially oil and gas companies, and (3) application of digital image processing to mineral exploration.

  2. Geology and origin of Ag-Pb-Zn deposits occurring in the Ulaan-Jiawula metallogenic province, northeast Asia

    NASA Astrophysics Data System (ADS)

    Nie, Feng-jun; Li, Qiang-feng; Liu, Chun-hua; Ding, Cheng-wu

    2015-01-01

    Located at the conjunction area of China, Mongolia and Russia in NE Asia, the Ulaan-Jiawula (also referred as UJ) region, with an area of 400,000 km2, is one of the most important Ag-Pb-Zn, U, Sn, W, Nb-Ta, and Au metallogenic provinces in Asia. At present, 2126 deposits and showings including 500 Ag-Pb-Zn deposits have been discovered, explored and mined since the late 1960s. These Ag-Pb-Zn occurrences can be subdivided into three types according to their geological setting, texture, alteration and mineral assemblages: (1) low sulfidation epithermal Ag-Pb-Zn deposits; (2) intermediate sulfidation epithermal Ag-Pb-Zn deposits; (3) mixed-type Ag-Pb-Zn deposit consisting of vein-like and tabular ore bodies. The Eren Tologoi and Tsagenbulagen deposits are representative of low-sulphidation type Ag-Pb-Zn mineralization in the UJ region, and are associated with intensive adularization and sericitization. Ore occurs as mineralized quartz veins, veinlet groups and altered-fracture zones within Mesozoic alkaline and high-K calc-alkaline volcanic rocks, Ore mineralogy includes native silver, electrum, pyrite, galena, sphalerite, arsenopyrite, pyrargyrite and chalcopyrite. The Tsav and Jiawula deposits are typical of intermediate sulfidation Ag-Pb-Zn mineralization. The δ34S value of sulfide (pyrite and galena) separates from groups 1 and 2 varies from 1.5‰ to 3.5‰ and 2.0‰ to 4.5‰, respectively. The δ34S values of the Mesozoic volcanic host rocks for groups 1 and 2 deposits also show the positive δ34S values of 1.5-4.8‰, while the δ34S value of pyrite separate from the pre-Jurassic schist range from -6‰ to -8‰ which are much lower than Mesozoic volcanic host rocks and their associated ore deposits. There is no difference between the δ34S value of sulfide (pyrite and galena) separates from vein-like ore bodies of the group 3 deposits and their wall rocks, having δ34S value of 1.0-5.0‰ and 1.2-4.5‰ which are similar to that of groups 1 and 2 deposits. For the Mesozoic monzogranite porphyry dykes and their associated tabular skarn ore bodies, the pyrite separates show δ34S values of 2-5‰ and 1.8-3‰. All of these deposits show relatively radiogenic lead isotopic compositions compared to mantle or lower crust curves. Most lead isotope data of sulfides from the Ag-Pb-Zn ores plot between the Mesozoic volcano-hypabyssal rocks and pre-Jurassic metamorphic rocks. Monzogranite dykes at Ulaan and Noyon Tologoi have εNd (T) values ranging from 1.5 to 4.5 that are similar to most of the Mesozoic granite with positive εNd (T) values in the Great Hinggan Mountains-Mongolia orogenic belt. Data are interpreted as indicative of a mixing of ore-forming materials from mantle-derived alkaline and high-K calc-alkaline magma with these from pre-Jurassic metamorphic wall rocks. Isotopic age data, geological and geochemical evidence suggest that the ore fluids for the Ag-Pb-Zn deposits were generated during eruption or emplacement of the Mesozoic alkaline and high-K calc-alkaline magma. The Mesozoic magmas may provide heat, volatiles and metals for the group 1 and 2 deposits. Evolved metamorphic fluids produced by devolatilization, circulated the wall rocks, were also progressively involved in the magmatic hydrothermal system, and may have dominated the ore fluids during late stage ore-forming processes. Most of the Ag-Pb-Zn bodies that occur along the contact of the pre-Jurassic marble and Cretaceous monzogranite porphyry dykes at Ulaan and Noyon Tologoi are closely associated with skarn. The ore fluid of these group 3 deposit may have resulted from the mixing of Mesozoic magmatic water and evolved metamorphic fluids. Ore deposition in this instance would be the product of the interaction of the Mesozoic intrusions and pre-Jurassic carbonate rocks.

  3. Theoretical geology

    NASA Astrophysics Data System (ADS)

    Mike, 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 erroneous assumptions and do not solve the very fundamental issue that lies at the base of the problem. This problem is straighforward and obvious: a sedimentary system is inherently four-dimensional (3 spatial dimensions + 1 temporal dimension). Any method using an inferior number or dimensions is bound to fail to describe the evolution of a sedimentary system. It is indicative of the present day geological world that such fundamental issues be overlooked. The only reason for which one can appoint the socalled "rationality" in todays society. Simple "common sense" leads us to the conclusion that in this case the empirical method is bound to fail and the only method that can solve the problem is the theoretical approach. Reasoning that is completely trivial for the traditional exact sciences like physics and mathematics and applied sciences like engineering. However, not for geology, a science that was traditionally descriptive and jumped to empirical science, skipping the stage of theoretical science. I argue that the gap of theoretical geology is left open and needs to be filled. Every discipline in geology lacks a theoretical base. This base can only be filled by the theoretical/inductive approach and can impossibly be filled by the empirical/deductive approach. Once a critical mass of geologists realises this flaw in todays geology, we can start solving the fundamental problems in geology.

  4. 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)

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  6. 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 studies and stage II mineral equilibria, gold deposited from a homogeneous, neutral to slightly alkaline (pH 5.1-5.5), reduced, low-salinity (<5.5 wt % NaCl equiv) fluid that had a bulk composition of 78 mole percent H2O and 21 mole percent CO2, and trace amounts of CH4, C2H6, H2, Ar, H2S, and He. Gold deposition occurred at 300?? ?? 50??C and 0.5 to 3.0 kbars. Assuming lithostatic fluid pressures, gold precipitated at a 2- to 10-km depth. Stage II gray quartz ??18Ofluid values range from 5.9 to 7.5 per mil, whereas ??Dfluid values calculated from the dehydration of muscovite grains and measured directly from bulk fluid inclusion analyses of stage II gray quartz have ranges of -9 to -35 and -27 to -28 per mil, respectively. Hydrothermal ore fluids were transported from greater crustal depths to the site of gold deposition during the district-scale D3 event by shallowly W dipping, reverse brittle-ductile shear zones in supracrustal rock and along the steeply east dipping trondhjemite contact. Associated subhorizontal east-west shortening caused the reactivation of the eastern trondhjemite margin and subparallel foliation, which facilitated the transport of hydrothermal fluids and the generation of gold-bearing veins and hydrothermal alteration zones in komatiite. East-west-striking fractures in trondhjemite aided the lateral migration of ore fluids away from trondhjemite margins and the formation of east-west-striking gold-bearing veins and broad alteration zones. Gold was most likely transported in the stage II fluid as bisulfide complexes. The sulfidation of trondhjemite and komatiite wall rock by the stage II fluid caused the destabilization of An bisulfide complexes and gold deposition. Potassium, Ca, and CO2 metasomatism of komatiite wall rock may have enhanced gold deposition via the acidification of the stage II fluid. The physicochemical characteristics of the Tarmoola ore fluid and relative timing of gold mineralization are consistent with the Yilgarn-wide,

  7. Geological speedometers

    NASA Astrophysics Data System (ADS)

    Khisina, Natal'ia R.

    1991-06-01

    It is pointed out that important information on the origin of minerals can be found in their cooling rates. In order to determine these rates, methods of geological 'speedometry' have been developed, which are based on the interpretation of crystallochemical data from the viewpioint of the thermal history of the minerals. It is noted that such studies started in connection with reserach on lunar soil, and can find application in the investigation of meteorites.

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

    USGS Publications Warehouse

    Brobst, Donald Albert

    1953-01-01

    This report describes the results of study and geologic mapping (1:12,000) in the 70-square-mile Plumtree area in the northeastern part of the Spruce Pine pegmatite district, on the Blue Ridge upland in western North Carolina. The district has been the chief domestic source of feldspar and sheet mica. The mining belt just west of the Blue Ridge Front trends northeast and is 25 miles long and 10 miles wide. The center of the Plumtree area lies 10 miles northeast of Spruce Pine pegmatite district, on the Blue Ridge upland in western North Carolina. The district has been the chief domestic source of feldspar and sheet mica. The mining belt just west of the Blue Ridge Front trends northeast and is 25 miles long and 10 miles wide. The center of the Plumtree area lies 10 miles northeast of Spruce Pine and includes parts of Mitchell and Avery Counties shown on the portions of the 7.5-minute Spruce Pine, Linville Falls, Newland, North Carolina, and Carvers Gap, North Carolina and Tennessee quadrangle. The topography varies from rugged mountains to rounded or flat topped hills near the entrenched, meandering master streams. Old erosion surfaces are approximately 600,1,100, 1,500, and 2,500 feet above the present master stream level. The area is in late youth or early maturity after rejuvenation.. The regionally metamorphosed rocks of the amophibolite facies form three mappable units: mica gneiss, mica schist, and hornblende rock. These rocks, perhaps of Precambrian age, are intimately interlayered with thicknesses of the individual layers ranging from less than one inch to several tons of feet. Field relationships and chemical data suggest that the mica (Carolina-type) rocks were derived from sandstones, graywackes, and shales and that the hornblende-rich (Roan-type) layers were derived from impure carbonate rocks. The igneous rocks include alaskite and associated pegmatite of early Paleozoic age (?), dunite and associated soapstone of a prepegmatite age, and a few diabasic 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

  9. 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., III

    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.

  10. Geologic Nozzles

    NASA Astrophysics Data System (ADS)

    Kieffer, Susan Werner

    1989-02-01

    Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. 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 gyeser 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 debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. The transport capacity in the rapids can be so great that the river contours the channel to a characteristic shape. This shape can be used to interpret the flood history of the Colorado River over the past 10³-105 years. The unity of fluid mechanics in these three natural phenomena is provided by the well-known analogy between gas flow and shallow-water flow in converging-diverging nozzles.

  11. Geologic nozzles

    NASA Astrophysics Data System (ADS)

    Kieffer, Susan Werner

    Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. 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, supercritical flow occurs where debris discharged from tributary canyons constricts the channel into the shape of a converging-diverging nozzle. The geometry of the channel in these regions can be used to interpret the flood history of the Colorado River over the past 103-105 years. The unity of fluid mechanics in these three natural phenomena is provided by the well-known analogy between gas flow and shallow-water flow in converging-diverging nozzles.

  12. 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.

  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. 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 precious-metal-rich silica-barite-carbonate white ores began at low temperature in a shallow, subaqueous setting, probably a thin carbonate shelf on the flanks of the Alexander landmass. Epigenetic carbonate replacement textures in the footwall dolostones are overlain by stratiform silica-carbonate-barite-rich ores and indicate that early mineralization formed at and just beneath the paleo sea floor by mixing of a reduced, precious-metal-rich, base-metal-poor hydrothermal fluid with oxygenated seawater. As rifting intensified, the shelf was downfaulted and isolated as a graben. Isolation of the basin and onset of starved-basin shale sedimentation was concurrent with emplacement of mafic-ultramafic intrusives at shallow levels in the rift, resulting in an increasingly higher temperature and progressively more anoxic ore-forming environment. The formation of the main stage of massive sulfide ores began as the supply of bacterially reduced sulfur increased in the accumulating shales. As the main-stage mineralization intensified, shale sedimentation inundated the hydrothermal system, eventually forming a cap. Biogenic sulfate reduction supplied reduced sulfur to the base of the shales where mixing occurred with hot, base-metal-rich hydrothermal fluids. Ore deposition continued by destruction and epigenetic replacement of the early white ores in proximal areas and by inflation and diagenetic replacement of unlithified shale at the interface between the white ores and the base of the shale cap. Ore deposition waned as the shales became lithified and as the supply of bacterially reduced sulfur to the site of ore deposition ceased. The final stages of rifting resulted in the emplacement of mafic-ultramafic intrusive rocks into the Greens Creek system and extrusion of voluminous basaltic flows at the top of the Triassic section. Greenschist facies metamorphism during the Jurassic-Cretaceous accretion of the Alexander terrane to the continental margin resulted in recrystalli

  15. 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 FieldSpec3 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.

  16. Vesta: A Geological Overview

    NASA Astrophysics Data System (ADS)

    Jaumann, R.

    2012-04-01

    Observations from the Dawn spacecraft [1] enable the derivation of the asteroid 4Vesta's shape, facilitate mapping of the surface geology, and provide the first evidence for interpreting Vesta's geological evolution. Science data were acquired during the approach to Vesta, a circular polar (Survey) orbit at an altitude of 2700 km providing ~ 230 m/pix camera scale, and during a circular high-altitude mapping orbit (HAMO) at 700 km altitude with a camera scale of ~ 65 m/pixel. Currently Dawn is orbiting Vesta in a low-altitude mapping orbit (LAMO) at 210 km altitude, yielding a global image coverage of ~20 m/pixel at the time of EGU [2,3,4,5]. Geomorphology and distribution of surface features provide evidence for impact cratering, tectonic activity, and regolith and probable volcanic processes. Craters with dark rays, bright rays, and dark rim streaks have been observed, suggesting buried stratigraphy. The largest fresh craters retain a simple bowl-shaped morphology, with depth/diameter ratios roughly comparable to lunar values. The largest crater Rheasilvia, an ~500 km diameter depression at the south pole, includes an incomplete inward facing cuspate scarp and a large central mound surrounded by unusual complex arcuate ridge and groove patterns, and overlies an older ~400 km wide basin. A set of large equatorial troughs is related to these south polar structures. Vesta exhibits rugged topography ranging from -22 km to +19 km relative to a best fit ellipsoidal shape. Vesta's topography has a much greater range in elevation relative to its radius (15%) than do the Moon and Mars (1%) or the Earth (0.3%), but less than highly battered smaller asteroids like Lutetia (40%). This also identifies Vesta as a transitional body between asteroids and planets. The surface of Vesta exhibits very steep topographic slopes that are near the angle of repose. Impacts onto these steep surfaces, followed by slope failure, make resurfacing - due to impacts and their associated gravitational forces and seismic activity - an important geologic process on Vesta that significantly alters the morphology of geologic features and adds to the complexity of its geologic history. In general, Vesta's geology is more like the Moon and rocky planets than other asteroids.

  17. Metamorphic geology

    NASA Astrophysics Data System (ADS)

    Peacock, Simon M.

    The complex heat- and mass-transfer processes of terrestrial metamorphism are described in a critical review of U.S. research from the period 1987-1990. Topics examined include metamorphic pressure-temperature-time paths and regional studies (crustal thickening, contact and subduction-zone metamorphism, crustal extension, and granulite facies metamorphism and crustal anatexis); metamorphic fluid-rock interaction in regional, contact, subduction-zone, and granulite terrains; metamorphic thermochemistry, phase relations, and mineral chemistry; metamorphic kinetics; and microstructures in metamorphic rocks. Textbooks and computer programs in metamorphic geology are briefly characterized, and it is concluded in general that a first-order explanation of the basic processes is now being developed. A comprehensive bibliography is provided.

  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 zone. However, irregularities in the distribution of some key elements, such as Au and Ag, relative to the predictive models suggest that a larger suite of elements be considered for exploration for ore zones within the district. ?? 1993.

  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 Pasadena.

  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 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 compositional banding in the intruded and included metamorphic rocks, formed late during batholith emplacement due to rising, buoyant magma and sinking, dense wall rocks. The Longs Peak-St Vrain batholith was intruded into crust that was structurally neutral or moderately extending in an east-northeast direction. A broad zone of mylonite, the Moose Mountain shear zone, formed within the batholith during the final stages of consolidation as a result of differential buoyancy between the magma and dense wall rock, not as a result of regional tectonic deformation.

  2. 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)

  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. 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.

  5. Visible Geology - Interactive online geologic block modelling

    NASA Astrophysics Data System (ADS)

    Cockett, R.

    2012-12-01

    Geology is a highly visual science, and many disciplines require spatial awareness and manipulation. For example, interpreting cross-sections, geologic maps, or plotting data on a stereonet all require various levels of spatial abilities. These skills are often not focused on in undergraduate geoscience curricula and many students struggle with spatial relations, manipulations, and penetrative abilities (e.g. Titus & Horsman, 2009). A newly developed program, Visible Geology, allows for students to be introduced to many geologic concepts and spatial skills in a virtual environment. Visible Geology is a web-based, three-dimensional environment where students can create and interrogate their own geologic block models. The program begins with a blank model, users then add geologic beds (with custom thickness and color) and can add geologic deformation events like tilting, folding, and faulting. Additionally, simple intrusive dikes can be modelled, as well as unconformities. Students can also explore the interaction of geology with topography by drawing elevation contours to produce their own topographic models. Students can not only spatially manipulate their model, but can create cross-sections and boreholes to practice their visual penetrative abilities. Visible Geology is easy to access and use, with no downloads required, so it can be incorporated into current, paper-based, lab activities. Sample learning activities are being developed that target introductory and structural geology curricula with learning objectives such as relative geologic history, fault characterization, apparent dip and thickness, interference folding, and stereonet interpretation. Visible Geology provides a richly interactive, and immersive environment for students to explore geologic concepts and practice their spatial skills.; Screenshot of Visible Geology showing folding and faulting interactions on a ridge topography.

  6. Geology of the Midnite uranium mine area, Washington: maps, description, and interpretation

    USGS Publications Warehouse

    Nash, J. Thomas

    1977-01-01

    Bedrock geology of about 12 km2 near the Midnite mine has been mapped at the surface, in mine exposures, and from drilling, at scales from 1:600 to 1:12,000 and is presented here at 1:12,000 to provide description of the setting of uranium deposits. Oldest rocks in the area are metapelitic and metacarbonate rocks of the Precambrian (Y) Togo Formation. The chief host for uranium deposits is graphitic and pyritic mica phyllite and muscovite schist. Ore also occurs in calc-silicate hornfels and marble at the western edge of a calcareous section about 1,150 m thick. Calcareous rocks of the Togo are probably older than the pelitic as they are interpreted to be near the axis of a broad anticline. The composition and structural position of the calcareous unit suggests correlation with less metamorphosed carbonate-bearing rocks of the Lower Wallace Formation, Belt Supergroup, about 200 km to the east. Basic sills intrusive into the Togo have been metamorphosed to amphibolite. Unmetamorphosed rocks in the mine area are Cretaceous(?) and Eocene igneous rocks. Porphyritic quartz monzonite of Cretaceous age, part of the Loon Lake batholith, is exposed over one third of the mine area. It underlies the roof pendant of Precambrian rocks in which the Midnite mine occurs at depths of generally less than 300 m. The pluton is a two-mica granite and exhibits pegmatitic and aplitic textural features indicative of water saturation and pressure quenching. Eocene intrusive and extrusive rocks in the area provide evidence that the Eocene surface was only a short distance above the present uranium deposits. Speculative hypotheses are presented for penesyngenetic, hydrothermal, and supergene modes of uranium emplacement. The Precambrian Stratigraphy, similar in age and pre-metamorphic lithology to that of rocks hosting large uranium deposits in Saskatchewan and Northern Territory, Australia, suggests the possibility of uranium accumulation along with diagenetic pyrite in carbonaceous muds in a marine shelf environment. This hypothesis is not favored by the author because there is no evidence for stratabound uranium such as high regional radioactivity in the Togo. A hydrothermal mode of uranium emplacement is supported by the close apparent ages of mineralization and plutonism, and by petrology of the pluton. I speculate that uranium may have become enriched in postmagmatic fluids at the top of the pluton, possibly by hydrothermal leaching of soluble uranium associated with magnetite, and diffused outward into metasedimentary wall rocks to create an aureole about 100 m thick containing about 100 ppm uranium. Chemistry of the hydrothermal process is not understood, but uranium does not appear to have been transported by an oxidizing fluid, and the fluid did not produce veining and alteration comparable to that of base-metal sulfide deposits. Uranium in the low-grade protore is believed to have been redistributed into permeable zones in the Tertiary to create ore grades. Geologic and isotopic ages of uranium mineralization, and the small volume of porphyritic quartz monzonite available for leaching, are not supportive of supergene emplacement of uranium.

  7. 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.

  8. History of Geology.

    ERIC Educational Resources Information Center

    Greene, Mott T.

    1985-01-01

    Discusses: (1) geologists and the history of geology; (2) American historians and the history of geology; (3) history of geology in the 1980s; (4) sources for the history of geology (bibliographies, dictionaries, encyclopedias, handbooks, periodicals, public/official histories, compilations, and books); (5) research opportunities; and (6) other

  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. Geology for the Masses

    ERIC Educational Resources Information Center

    Dickinson, William R.

    1970-01-01

    Describes environmental geology as including planning to avoid natural hazards, acquire natural resources, and use land wisely. Describes philosophy and strategies for developing interdisciplinary, environmental geology education at the high school, college, professional graduate, and doctoral research levels. (PR)

  11. Geologic spatial analysis

    SciTech Connect

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

    1989-01-01

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

  12. Geological Survey research 1976

    USGS Publications Warehouse

    U.S. Geological Survey

    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. Geological Survey research 1978

    USGS Publications Warehouse

    U.S. Geological Survey

    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)

  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. DNA ALTERATIONS

    EPA Science Inventory

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

  16. Geological Survey research 1981

    USGS Publications Warehouse

    U.S. Geological Survey

    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. (USGS)

  17. Geologic time scale bookmark

    USGS Publications Warehouse

    U.S. Geological Survey

    2012-01-01

    This bookmark, designed for use with U.S. Geological Survey activities at the 2nd USA Science and Engineering Festival (April 2629, 2012), is adapted from the more detailed Fact Sheet 20103059 "Divisions of Geologic Time." The information that it presents is widely sought by educators and students.

  18. 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.

  19. 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)

  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. 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.…

  2. 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.

  3. 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)

  4. 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.

  5. 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.

  6. Environmental geology of the Summitville mine, Colorado

    USGS Publications Warehouse

    Gray, John E.; Coolbaugh, Mark F.; Plumlee, Geoffrey S.; Atkinson, William W.

    1994-01-01

    Although altered and mineralized rocks at Summitville mine in Colorado contain minimal amount of sulfide minerals, acid mine problems existed primarily because of the pervasive alteration of the surrounding rocks, through hydrothermal process, to highly siliceous and argillized rocks that are incapable of buffering acidic waters during weathering. The problems are compounded by the continued exposure of altered and mineralized rocks in open pit, heap leach pad and waste piles to oxygenated waters. Inadequate subsurface structural control and underground mine workings also greatly affect water quality and the location of acid mine drainage output. It is expected that with these initial results, geological studies on constrained acid-generation from ore and altered rocks will be pursued.

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

    SciTech Connect

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

    1984-10-01

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

  8. Fundamentals of Structural Geology

    NASA Astrophysics Data System (ADS)

    Pollard, David D.; Fletcher, Raymond C.

    2005-09-01

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

  9. Geologic effects of hurricanes

    NASA Astrophysics Data System (ADS)

    Coch, Nicholas K.

    1994-08-01

    Hurricanes are intense low pressure systems of tropical origin. Hurricane damage results from storm surge, wind, and inland flooding from heavy rainfall. Field observations and remote sensing of recent major hurricanes such as Hugo (1989), Andrew (1992) and Iniki (1992) are providing new insights into the mechanisms producing damage in these major storms. Velocities associated with hurricanes include the counterclockwise vortex winds flowing around the eye and the much slower regional winds that steer hurricane and move it forward. Vectorial addition of theseof these two winds on the higher effective wind speed than on the left side. Coast-parallel hurricane tracks keep the weaker left side of the storm against the coast, whereas coast-normal tracks produce a wide swath of destruction as the more powerful right side of the storm cuts a swath of destruction hundreds of kilometers inland. Storm surge is a function of the wind speed, central pressure, shelf slope, shoreline configuration, and anthropogenic alterations to the shoreline. Maximum surge heights are not under the eye of the hurricane, where the pressure is lowest, but on the right side of the eye at the radius of maximum winds, where the winds are strongest. Flood surge occurs as the hurricane approaches land and drives coastal waters, and superimposed waves, across the shore. Ebb surge occurs when impounded surface water flows seaward as the storm moves inland. Flood and ebb surge damage have been greatly increased in recent hurricanes as a result of anthropogenic changes along the shoreline. Hurricane wind damage occurs on three scales — megascale, mesoscale and microscale. Local wind damage is a function of wind speed, exposure and structural resistance to velocity pressure, wind drag and flying debris. Localized extreme damage is caused by gusts that can locally exceed sustained winds by a factor of two in areas where there is strong convective activity. Geologic changes occuring in hurricanes include beach erosion, dune erosion, inlet formation from flood and ebb surge, landscape changes through tree destruction by wind and nearshore channeling and sedimentation resulting from ebb surge. Multi-decadal wet and dry cycles in West Africa seem to be associated with increases (wet periods) and decreases (dry periods) in the frequency of Atlantic Coast landfalling hurricanes. Coastalzone population and development has increased markedly in a time of low hurricane frequency in the 24 year dry cycle from1970 to the present. However, no previous climatic cycle in this century has exceeded 26 years. We may entering a multi-decadal cycle of greater hurricane activity, placing these highly urbanized shorelines in considerable danger.

  10. 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)

  11. Geology of caves

    USGS Publications Warehouse

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

    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.

  12. Glossary of Geology

    NASA Astrophysics Data System (ADS)

    Jackson, Julia A.

    The Glossary has expanded coverage particularly in such active fields as carbonate sedimentology, environmental geology and geophysics, GIS, GPS, hydrology and hydraulics, marine and coastal geology, organic geochemistry, paleoecology, seismology, stratigraphic nomenclature, speleology and karst, and structural geology and tectonics. Many definitions provide a syllabification guide and background information. Thus a reader will learn the difference between look-alike pairs, such as sylvanite (a mineral) and sylvinite (a rock); the origin of terms; the meaning of abbreviations and acronyms common in the geosciences vocabulary; the dates many terms were first used; the meaning of certain prefixes; and the preferred term of two or more synonyms.

  13. 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.

  14. Experiencing Structural Geology

    ERIC Educational Resources Information Center

    Davis, George H.

    1978-01-01

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

  15. 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)

  16. 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.

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

    USGS Publications Warehouse

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

    2005-01-01

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

  18. The Geology of Australia

    NASA Astrophysics Data System (ADS)

    Johnson, David

    2004-12-01

    The Geology of Australia provides a vivid and informative account of the evolution of the Australian continent over the past 4400 million years. Starting with the Precambrian rocks which hold clues to the origins of life and the development of an oxygenated atmosphere, it then covers the warms seas, volcanism and multiple orogenies of the Palaeozoic, which built the eastern third of the Australian continent. This illuminating history then details the breakup of Gondwana and the development of the continental shelves and coastlines. Separate chapters cover the origin of the Great Barrier Reef, the basalts in Eastern Australia and the geology of the Solar System. From Uluru to the Great Dividing Range, from sapphires to the stars, The Geology of Australia is a comprehensive exploration of the timeless forces that have shaped this continent and that continue to do so.

  19. Geologic map of Mars

    USGS Publications Warehouse

    Tanaka, Kenneth L.; Skinner, James A.; Dohm, James M.; Irwin, Rossman P., III; 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.

  20. 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.

  1. The geology of Ganymede

    NASA Technical Reports Server (NTRS)

    Shoemaker, E. M.; Lucchitta, B. K.; Wilhelms, D. E.; Plescia, J. B.; Squyres, S. W.

    1982-01-01

    A broad outline of the geologic history of Ganymede is presented, obtained from a first attempt to map the geology on a global scale and to interpret the characteristics of the observed geologic units. Features of the ancient cratered terrain such as craters and palimpsests, furrows and troughs, are discussed. The grooved terrain is described, including its sulci and cells, and the age relation of these units is considered along with the structure and origin of this terrain. The Gilgamesh Basin and Western Equatorial Basin in the post grooved terrain are treated, as are the bright and dark ray craters and the regolith. The development of all these regions and features is discussed in context. For the regolith, this includes the effect of water migration, sputtering, and thermal annealing. The histories of the ancient cratered terrain, the grooved terrain, and the post grooved terrain are presented.

  2. Petroleum development geology

    SciTech Connect

    Dickey, P.A.

    1986-01-01

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

  3. Planetary geological processes

    NASA Astrophysics Data System (ADS)

    Lopes, Rosaly M. C.; Solomonidou, Anezina

    2014-11-01

    In this introduction to planetary geology, we review the major geologic processes affecting the solid bodies of the solar system, namely volcanism, tectonism, impact cratering, and erosion. We illustrate the interplay of these processes in different worlds, briefly reviewing how they affect the surfaces of the Earth's Moon, Mercury, Venus and Mars, then focusing on two very different worlds: Jupiter's moon Io, the most volcanically active object in the solar system, and Saturn's moon Titan, where the interaction between a dense atmosphere and the surface make for remarkably earth-like landscapes despite the great differences in surface temperature and composition.

  4. The Geology of Earthquakes

    NASA Astrophysics Data System (ADS)

    Wallace, Robert E.

    The Geology of Earthquakes is a major contribution that brings together under one cover the many and complex elements of geology that are fundamental to earthquakes and seismology. Here are described and analyzed the basic causes of earthquakes, the resulting effects of earthquakes and faulting on the surface of the Earth, techniques of analyzing these effects, and engineering and public policy considerations for earthquake hazard mitigation. The three authors have played major roles in developing the fundamentals in both scientific and policy matters; thus they speak with an authority that few others could.

  5. 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.

  6. Geologic Data Systems

    USGS Multimedia Gallery

    Several of the systems used for viewing and storing geologic data as it's captured from the onboard instrumentation. The USGS returned from a seafloor data mapping mission offshore of the Delmarva Peninsula (Ocean City, MD) on July 25th, 2014. The data collected is foundational to our continued und...

  7. 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....

  8. 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." Included are a list of objectives, an outline

  9. IDAHO FLUVIAL GEOLOGY

    EPA Science Inventory

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

  10. Appendix E: Geology

    SciTech Connect

    Reidel, Steve; Chamness, Mickie A.

    2008-01-17

    This appendix provides a detailed description of geology under the Central Plateau of the Hanford Site, emphasizing the areas around tank farms. It is to be published by client CH2M HILL Hanford Group, Inc., as part of a larger, multi-contractor technical report.

  11. 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." Included are a list of objectives, an outline…

  12. 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...

  13. 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...

  14. Geology en Espanol

    ERIC Educational Resources Information Center

    McGehee, Richard V.

    1973-01-01

    Describes a program in which an introductory geology class was conducted in Spanish at Western Michigan University. Although difficulties were encountered, the author evaluated the program as a great success, and a valuable experience for the person who wants to be effectively bilingual in his profession. (JR)

  15. 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…

  16. 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 following…

  17. 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 following

  18. 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.

  19. 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 additional

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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)

  5. Geological Survey research, 1975

    USGS Publications Warehouse

    U.S. Geological Survey

    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)

  6. 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.

  7. 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.

  8. Principles of nuclear geology

    SciTech Connect

    Aswathanarayana, U.

    1985-01-01

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

  9. 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

  10. The Second Flowering of Geology.

    ERIC Educational Resources Information Center

    Cloud, Preston

    1983-01-01

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

  11. 77 FR 19032 - Geological Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... Geological Survey Announcement of National Geospatial Advisory Committee Meeting AGENCY: U.S. Geological Survey, Interior. ACTION: Notice of meeting. SUMMARY: The National Geospatial Advisory Committee (NGAC... advance. Please register by contacting Arista Maher at the U.S. Geological Survey (703-648-6283,...

  12. Geologic Map of North America

    USGS Multimedia Gallery

    The Geologic Map of North America is a product of GSA's Decade of North American Geology (DNAG) project. At a scale of 1:5,000,000, this map covers ~15% of Earth's surface and differs from previous maps in several important respects: it is the first such map to depict the geology of the seafloor, th...

  13. The Second Flowering of Geology.

    ERIC Educational Resources Information Center

    Cloud, Preston

    1983-01-01

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

  14. 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.

  15. 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.

  16. 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 330C. Samples for this study were obtained from the Iceland Deep Drilling Project (IDDP). The core contains hydrothermally altered rocks of basaltic composition. Hydrothermal alteration ranges from upper greenschist to lower amphibolite grade, dependent on protolith size and composition. Veins in the core grade inward from radial epidote + acicular hornblende + titanite + pyrite, to clearer equant and compositionally zoned epidote vein centers. Felted amphibole replaces hyaloclastite and smaller crystalline clasts within the core, but is absent from the centers of crystalline pillow basalt fragments. Amphibole in vein selvages and vesicle fillings is green and acicular. Electron microprobe analyses of amphibole indicate it spans a compositional range of ferrohornblende through paragasite. The pistacite component (Xps) of vein epidote ranges from 16.5 to 36.7. The Xps component shows both normal and reverse zoning within single epidote crystals across this range, and follows no distinct pattern. Vein epidote adjacent to the wall rock has a higher aluminum concentration than vein centers. This may be due to mobilization of aluminum from plagioclase in the wall rock during albitization. Solutions flowing through open fractures may have lower Al-content and thus precipitate more Fe-rich epidote than those next to the fracture walls. Primary fluid inclusions in epidote range in size from <1 to 10 ?m in diameter. Secondary fluid inclusions are <1 ?m in diameter and not measurable. Calculated fluid inclusion salinities range from 0.5 to 7.6 weight percent NaCl, with lower salinities adjacent to the wall rock and higher salinities in the vein centers. Homogenization temperature (Th) measurements fall into 3 categories: 1) non-homogenizing adjacent to vein walls; 2) inwards of vein wall (Th = 383.6 to 401.5C); and 3) the vein center (Th = 344.9 to 378.3C). Laser ablation ICP-MS spot measurements of strontium isotope (87Sr/86Sr) ratios decrease from the vein edges (0.70500) to the vein centers (0.70400). 87Sr/86Sr isotope ratios are overall shifted away from oceanic basalt values towards seawater values. Lower 87Sr/86Sr ratios in the vein centers indicate an evolution of the system to lower water/rock ratios. If this conclusion is correct, lower water/rock ratio may be responsible for salinities greater than seawater in the vein centers following wall rock hydration.

  17. 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 emplaced; these lie stratigraphically above the equatorial ridges that likely were formed by Rheasilvia. The last features to be formed were craters with bright rays and other surface mantling deposits. Executed progressively throughout data acquisition, the iterative mapping process provided the team with geologic proto-units in a timely manner. However, interpretation of the resulting map was hampered by the necessity to provide the team with a standard nomenclature and symbology early in the process. With regard to mapping and interpreting units, the mapping process was hindered by the lack of calibrated mineralogic information. Topography and shadow played an important role in discriminating features and terrains, especially in the early stages of data acquisition.

  18. Groundwater in Geologic Processes

    NASA Astrophysics Data System (ADS)

    Person, Mark

    Any student of geology who inspects a sample of galena or fluorite from one of the lead-zinc mines of the Mississippi Valley Ore district will be immediately struck by the hydrologic processes that were required to concentrate the requisite far-flung chemical components into a relatively thin layer of limestone. What was the nature and scale of the flow system that formed this ore body? How long did it last? Was it unlike modern flow systems? Until recently, these questions have been the sole domain of economic geologists.

  19. 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 length of the island and to American troop movement. This unique topography forced innovative tactics ranging from reverse slope defense to "blowtorch and corkscrew" offense in response. During this exercise, students apply their map-reading and interpretation skills, as well as their critical analysis abilities; the historical context, in turn, provides motivation to refine those skills. Sun Tzu wrote that all warfare is based on deception. What we hope to communicate to students with this activity is that much of warfare, and, more broadly, the way humans interact with the world, is inherently and undeniably based on geology.

  20. 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 emplaced; these lie stratigraphically above the equatorial ridges that likely were formed by Rheasilvia. The last features to be formed were craters with bright rays and other surface mantling deposits. Executed progressively throughout data acquisition, the iterative mapping process provided the team with geologic proto-units in a timely manner. However, interpretation of the resulting map was hampered by the necessity to provide the team with a standard nomenclature and symbology early in the process. With regard to mapping and interpreting units, the mapping process was hindered by the lack of calibrated mineralogic information. Topography and shadow played an important role in discriminating features and terrains, especially in the early stages of data acquisition.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

    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 carbon (TOC) content in weight percent. Although the RockEval and TOC data are included in this chapter (table 1), they are not shown on the maps. The revised CAI isograd and percent vitrinite reflectance isograd maps cover all or parts of Kentucky, New York, Ohio, Pennsylvania, Virginia, and West Virginia (fig. 1), and the following three stratigraphic intervals: Upper Ordovician carbonate rocks, Lower and Middle Devonian carbonate rocks, and Middle and Upper Devonian black shales. These stratigraphic intervals were chosen for the following reasons: (1) they represent target reservoirs for much of the oil and gas exploration in the Appalachian basin; (2) they are stratigraphically near probable source rocks for most of the oil and gas; (3) they include geologic formations that are nearly continuous across the basin; (4) they contain abundant carbonate grainstone-packstone intervals, which give a reasonable to good probability of recovery of conodont elements from small samples of drill cuttings; and (5) the Middle and Upper Devonian black shale contains large amounts of organic matter for RockEval, TOC, and dispersed vitrinite analyses. Thermal maturity patterns of the Upper Ordovician Trenton Limestone are of particular interest here, because they closely approximate the thermal maturity patterns in the overlying Upper Ordovician Utica Shale, which is the probable source rock for oil and gas in the Upper Cambrian Rose Run Sandstone (sandstone), Upper Cambrian and Lower Ordovician Knox Group (Dolomite), Lower and Middle Ordovician Beekmantown Group (dolomite or Dolomite), Upper Ordovician Trenton and Black River Limestones, and Lower Silurian Clinton/Medina sandstone (Cole and others, 1987; Jenden and others, 1993; Laughrey and Baldassare, 1998; Ryder and others, 1998; Ryder and Zagorski, 2003). The thermal maturity patterns of the Lower Devonian Helderberg Limestone (Group), Middle Devonian Onondaga Limestone, and Middle Devonian Marcellus Shale-Upper Devonian Rhine street Shale Member-Upper Devonian Ohio Shale are of interest, because they closely approximate the thermal maturity patterns in the Marcellus Shale, Upper Devonian Rhinestreet Shale Member, and Upper Devonian Huron Member of the Ohio Shale, which are the most important source rocks for oil and gas in the Appalachian basin (de Witt and Milici, 1989; Klemme and Ulmishek, 1991). The Marcellus, Rhinestreet, and Huron units are black-shale source rocks for oil and (or) gas in the Lower Devonian Oriskany Sandstone, the Upper Devonian sandstones, the Middle and Upper Devonian black shales, and the Upper Devonian-Lower Mississippian(?) Berea Sandstone (Patchen and others, 1992; Roen and Kepferle, 1993; Laughrey and Baldassare, 1998).

  5. 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.

  6. 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. Geographic Information System and metadata on most geologic features are available on the Geologic map of the Sheep Hole Mountains 30 by 60 quadrangle, U.S. Geological Survey map MF2234, scale 1:100,000, available at http://pubs.usgs.gov/mf/2002/2344/.

  7. Geological considerations for lunar telescopes

    NASA Technical Reports Server (NTRS)

    Taylor, G. Jeffrey

    1988-01-01

    The geological features of the Moon that may be advantageous for astronomical observations are listed and described. The Moon's geologic environment offers wondrous opportunities for astronomy and presents fascinating challenges for engineers designing telescope facilities on the lunar surface. The geologic nature of the stark lunar surface and the Moon's tenuous atmosphere are summarized. The Moon as a stable platform is described as is its atmosphere, surface temperatures, its magnetic field, its regolith, and its crater morphologies.

  8. 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 713, 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 (1990present), Galileo (19962001), 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 520 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 1995September 2003), and the results have been summarized in books published after the end of the Galileo Mission. Our mapping incorporates this new understanding to assist in map unit definition and to provide a global synthesis of Io's geology.

  9. Practical aspects of geological prediction

    SciTech Connect

    Mallio, W.J.; Peck, J.H.

    1981-11-01

    Nuclear waste disposal requires that geology be a predictive science. The prediction of future events rests on (1) recognizing the periodicity of geologic events; (2) defining a critical dimension of effect, such as the area of a drainage basin, the length of a fault trace, etc; and (3) using our understanding of active processes the project the frequency and magnitude of future events in the light of geological principles. Of importance to nuclear waste disposal are longer term processes such as continental denudation and removal of materials by glacial erosion. Constant testing of projections will allow the practical limits of predicting geological events to be defined. 11 refs.

  10. 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.

  11. Geological consequences of superplumes

    NASA Astrophysics Data System (ADS)

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

  12. 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., III; 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, rough inner, and annular massif) and exterior (continuous ejecta) subunits. Structural features and landforms are shown with conventional symbols. Type localities for the units are identified, along with suggestions for portraying the features on geological maps, including colors and letter abbreviations for material units. Implementing these suggestions by the planetary mapping community would facilitate comparisons of maps for different parts of Europa and contribute to an eventual global synthesis of its complex geology. On the basis of initial mapping results, a stratigraphic sequence is suggested in which ridged plains form the oldest unit on Europa, followed by development of band material and individual ridges. Band materials tend to be somewhat older than ridges, but in many areas the two units formed simultaneously. Similarly, the formation of most chaos follows the development of ridged plains; although chaos is among the youngest materials on Europa, some chaos units might have formed contemporaneously with ridged plains. Smooth plains generally embay all other units and are late-stage in the evolution of the surface. C1 craters are superposed on ridged plains but are crosscut by other materials, including bands and ridges. Most c2 craters postdate all other units, but a few c2 craters are cut by ridge material. C3 craters constitute the youngest recognizable material on Europa. Copyright 2000 by the American Geophysical Union.

  13. 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.

  14. Geologic repository licensing strategy

    SciTech Connect

    Berkowitz, L.; Stern, M.E.; Roberts, J.P.; Desell, L.J.

    1993-12-31

    The U.S. Department of Energy Office of Civilian Radioactive Waste Management`s objective is to characterize and determine the suitability of the Yucca Mountain site and, if this site is found suitable, obtain authorization from the U.S. Nuclear Regulatory Commission to construct, operate, and eventually close a geologic repository at that site. The Department`s licensing strategy involves the application of a process, the licensing process, that addresses the achievement of each of the elements of this objective. The applicable laws and regulations with which the Department must comply, including the Nuclear Waste Policy Act, as amended, the Energy Policy Act of 1992, the Atomic Energy Act of 1954, the National Environmental Policy Act, and the administrative Procedure Act, provide insights into what DOE must do if it is to achieve its objective. The Department`s licensing strategy, discussed in this paper, is based on these insights.

  15. 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.

  16. 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.

  17. 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 geologic framework model (200 feet [61 meters]), discussed in Section 6.4.2, limits the size of features that can be resolved by the model but is appropriate for the distribution of data available and its intended use. Uncertainty and limitations are discussed in Section 6.6 and model validation is discussed in Section 7.

  18. Effect of Hydrothermal Alteration on Rock Properties in Active Geothermal Setting

    NASA Astrophysics Data System (ADS)

    Mikisek, P.; Bignall, G.; Sepulveda, F.; Sass, I.

    2012-04-01

    Hydrothermal alteration records the physical-chemical changes of rock and mineral phases caused by the interaction of hot fluids and wall rock, which can impact effective permeability, porosity, thermal parameters, rock strength and other rock properties. In this project, an experimental approach has been used to investigate the effects of hydrothermal alteration on rock properties. A rock property database of contrastingly altered rock types and intensities has been established. The database details horizontal and vertical permeability, porosity, density, thermal conductivity and thermal heat capacity for ~300 drill core samples from wells THM12, THM13, THM14, THM17, THM18, THM22 and TH18 in the Wairakei-Tauhara geothermal system (New Zealand), which has been compared with observed hydrothermal alteration type, rank and intensity obtained from XRD analysis and optical microscopy. Samples were selected from clay-altered tuff and intercalated siltstones of the Huka Falls Formation, which acts as a cap rock at Wairakei-Tauhara, and tuffaceous sandstones of the Waiora Formation, which is a primary reservoir-hosting unit for lateral and vertical fluid flows in the geothermal system. The Huka Falls Formation exhibits argillic-type alteration of varying intensity, while underlying Waiora Formations exhibits argillic- and propylithic-type alteration. We plan to use a tempered triaxial test cell at hydrothermal temperatures (up to 200C) and pressures typical of geothermal conditions, to simulate hot (thermal) fluid percolation through the rock matrix of an inferred "reservoir". Compressibility data will be obtained under a range of operating (simulation reservoir) conditions, in a series of multiple week to month-long experiments that will monitor change in permeability and rock strength accompanying advancing hydrothermal alteration intensity caused by the hot brine interacting with the rock matrix. We suggest, our work will provide new baseline information concerning fluid-rock interaction processes in geothermal reservoirs, and their effects on rock properties, that will aid improved understanding of the evolution of high-temperature geothermal systems, provide constraints to parameterization of reservoir models and assist future well planning and design through prediction of rock properties in the context of drilling strategies.

  19. 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.

  20. 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)

  1. Computer Assisted Instruction in Geology.

    ERIC Educational Resources Information Center

    Lepp, Henry

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

  2. 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

  3. 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…

  4. 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

  5. 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…

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

    USGS Publications Warehouse

    Parker, John Mason

    1963-01-01

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

  7. 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 therefore strengthened the greenhouse effect by pressure broadening the absorption of greenhouse gases. In addition,the behaviour of N is dependent on redox conditions in the ocean, which have not been constant over time.

  8. Abiotic Alteration of Goethite Nanoparticles

    NASA Astrophysics Data System (ADS)

    Guyodo, Y. J. B.; Till, J. L.; Lagroix, F.; Ona-Nguema, G.; Morin, G.

    2014-12-01

    Goethite is a common iron-bearing mineral found in very diverse geological settings. It often occurs as particles made of nanoscale crystallites, which tend to increase its reactivity. At this meeting, we will present alteration experiments of nano-goethite particles after moderate heating in reducing or oxidizing atmospheres. Initial, intermediate, and final products of these experiments were characterized using low-temperature and room-temperature magnetometry, as well as non-magnetic techniques such as transmission electron microscopy and x-ray diffraction. Our results show that alteration of poorly crystalline nanophase goethite can produce strongly magnetic iron oxide nanoparticles. As a consequence, nano-goethite likely represents an important precursor of magnetic nanoparticles in the environment, which may impact a large number of paleoclimate, paleoenvironmental, and paleomagnetic studies. In particular, our experiments show that synthetic oriented aggregates of goethite nanoparticles can be easily converted to stoichiometric, highly crystalline, single-domain magnetite particles, including a substantial number of euhedral grains with morphologies similar to those of magnetosomes found in magnetotactic bacteria. Moreover, we demonstrate that such abiotic magnetite meets several of the biogenicity criteria commonly used for the identification of magnetofossils.

  9. 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.

  10. Geology of the BK9 kimberlite (Damtshaa, Botswana): implications for the formation of dark volcaniclastic kimberlite

    NASA Astrophysics Data System (ADS)

    Buse, B.; Sparks, R. S. J.; Field, M.; Schumacher, J. C.; Chisi, K.; Tlhaodi, T.

    2011-10-01

    The BK9 kimberlite consists of three overlapping pipes. It contains two dark varieties of massive volcaniclastic kimberlite, informally termed dark volcaniclastic kimberlite (DVK). DVK(ns) is present in the north and south pipes and is interbedded with lenses of basalt breccia at the margins of the pipes. DVK(c) is present within the central pipe where it is overlain by a sequence of basalt breccias with interbedded volcanogenic sediments. The features observed within the DVK units of the BK9 kimberlite provide strong evidence for gas fluidisation of the accumulating pyroclastic material. These include the massive interior of the pipes, marginal epiclastic units, well-dispersed country-rock xenoliths and small-scale heterogeneities in lithic clast abundance. The upper portions of the central pipe provide a record of the transition from pyroclastic eruption and infill to passive epiclastic infilling of the crater, after the eruption has ceased. The wall-rock of the BK9 kimberlite dips inwards and is interpreted as post pipe-fill subsidence of the adjacent country rock. The two DVK units contain interstitial, silt-sized pyroclasts. The DVK(ns) has a higher fraction of former melt and displays evidence of incipient welding, as a result of differences in eruption dynamics. These units demonstrate that whilst DVK is comparable in many respects to MVK and forms part of a spectrum of volcaniclastic rocks formed by fluidisation, it differs in frequently containing silt-sized particles and including agglutinated and welded varieties with a high melt fraction. The DVK varieties, studied here, also have a distinctive hydrothermal assemblage, resulting from the abundance of low-silica accidental lithic clasts. Both the hydrothermal alteration and the abundance of silt-sized particles contribute to the DVKs distinctive dark colour.

  11. Geology, gravitation, cosmology

    NASA Astrophysics Data System (ADS)

    Zelinsky, I. P.; Kuzjmenko, G. I.

    This paper is devoted to the memory of G. A. Gamow and considers basic problems of standard cosmology and its modern development including quantum cosmology. Therefore, the paper marks the difficulties in this branch of science (among the myths, religion, and the physical aspects) and pays attention to cosmological conceptions being shaky and to the necessity to take into account some existing gravitational and cosmological versions for working out a more generally accepted one. The potential fruitfulness of using modern concepts of synergetics, fractal and soliton-wavemechanical theory is noted, too. Attention is also payed to the significance of the newest geological and geophysical data to extend the observational material. It is shown that the cyclic character of the processes, the hierarchy of the structures, and the planet energy, being studied in detail and thoroughly, are of universal significance. It is shown too, that, from these materials on the universal cyclicity, structureness and transformation of gravitation energy into electromagnetic radiation, it should be useful to undertake new studies and to find possible improvements of standard cosmology and of its modern developments, including quantum cosmology.

  12. Petroleum geology of Kuwait

    SciTech Connect

    Youash, Y.

    1988-01-01

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

  13. Uranium geology of Bulgaria

    SciTech Connect

    Not Available

    1993-02-01

    Three major uranium districts containing several deposits, plus 32 additional deposits, have been identified in Bulgaria, all of which are detailed geologically in this article. Most of the deposits are located in the West Balkan mountains, the western Rhodope mountains, and the Thracian Basin. A few deposits occur in the East Balkan, eastern Rhodope and Sredna Gora mountains. The types of deposits are sandstone, vein, volcanic, and surficial. Sandstone deposits are hosted in Permian and Tertiary sediments. In early 1992, fifteen deposits were being exploited, of which roughly 70 percent of the uranium produced was being recovered using in-situ leaching (ISL) methods. The remainder was being recovered by conventional underground mining, except for one small deposit that utilized open-pit methods. Fifteen other Bulgarian deposits had been exhausted, while five deposits were still in the exploration stage. Uranium production began in Bulgaria in 1946, and cumulative production through 1991 exceeded 100 million pounds equivalent U3O8. Current annual production is on the order of one million pounds equivalent U3O8, about 750 thousand pounds of which are recovered by ISL operations.

  14. 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

    2014-01-01

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

  15. Multi- and hyperspectral geologic remote sensing: A review

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  16. Thermal-infrared spectral observations of geologic materials in emission

    NASA Technical Reports Server (NTRS)

    Christensen, Philip R.; Luth, Sharon J.

    1987-01-01

    The thermal-infrared spectra of geologic materials in emission were studied using the prototype Thermal Emission Spectrometer (TES). A variety of of processes and surface modifications that may influence or alter the spectra of primary rock materials were studied. It was confirmed that thermal emission spectra contain the same absorption features as those observed in transmission and reflection spectra. It was confirmed that the TES instrument can be used to obtain relevant spectra for analysis of rock and mineral composition.

  17. 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...

  18. 30 CFR 780.22 - Geologic information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) 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...

  19. 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...

  20. 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...

  1. 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...

  2. Chapter B in Geological Survey research 1966

    USGS Publications Warehouse

    U.S. Geological Survey

    1966-01-01

    This collection of 43 short papers is the first published chapter of 'Geological Survey Research 1966.' The papers report on scientific and economic results of current work by members of the Conservation, Geologic, Topographic, and Water Resources Divisions of the U.S. Geological Survey. Chapter A, to be published later in the year, will present a summary of significant results of work done during fiscal year 1966, together with lists of investigations in progress, reports published, cooperating agencies, and Geological Survey offices. 'Geological Survey Research 1966' is the seventh volume of the annual series Geological Survey Research. The six volumes already published are listed below, with their series designations. Geological Survey Research 1960-Prof. Paper 400 Geological Survey Research 1961-Prof. Paper 424 Geological Survey Research 1962-Prof. Paper 450 Geological Survey Research 1963-Prof. Paper 475 Geological Survey Research 1964-Prof. Paper 501 Geological Survey Research 1965-Prof. Paper 525

  3. The Essence of Urban Environmental Geology

    ERIC Educational Resources Information Center

    McKenzie, Garry D.; And Others

    1978-01-01

    Provides 60 quotations relating to urban geology, geologic hazards, engineering aspects of land use, urban resources, and geology and regional planning which have proven useful in developing central themes for lecture topics and student projects. (SL)

  4. 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.

  5. Outreach at Geology Camp 2008

    USGS Multimedia Gallery

    USGS Hydrologist, Andy Long, demonstrates an interactive groundwater-flow model in the USGS South Dakota Water Science Center laboratory to students attending Geology Camp with the South Dakota School of Mines in 2008....

  6. 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)

  7. 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.

  8. 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.

  9. Geology in Our Everyday Lives.

    ERIC Educational Resources Information Center

    Mirsky, Arthur

    1989-01-01

    Discusses methods to help the public recognize the geologic aspect of societal problems. Suggests using methods that will arouse immediate interest and demonstrate relevance in direct and personal ways. (MVL)

  10. 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.

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

    SciTech Connect

    Not Available

    1985-08-01

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

  12. Northeastern Regional geologic characterization report. Volume 1. Final report

    SciTech Connect

    Not Available

    1985-08-01

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

  13. 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.

  14. 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 (Ost?ihansk 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 Komorn H?rka (Kammerbhls) 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 body exposed to strong tidal action of Moon and Sun. Ostrihansky, L.: The structure of the earth's crust and the heat-flow--heat-generation relationship in the Bohemian Massif. Tectonophysics, 68(3-4), 325-337, doi:10.1016/0040-1951(80)90182-1 1980.

  15. 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.

  16. 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., Jr.; Rankin, Douglas W.; Doolan, Barry L.; Kim, Jonathan; Mehrtens, Charlotte J.; Aleinikoff, John N.; McHone, J. Gregory; Cartography by Masonic, Linda M.

    2011-01-01

    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.

  17. 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.

  18. 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.

  19. 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.

  20. 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 systems that flow south from the lode-bearing central zone. Carlin-like gold deposits have only been identified during the last decade in the southern zone of the western Qinling and in the northeastern corner of the Songpan-Ganzi basin. The deposits mainly contain micron-diameter gold in arsenical pyrite; are characterized by the common occurence of cinnabar, stibnite, realgar, and orpiment; exhibit strong silicification, carbonatization, pyritization, and decalcification dissolution textures; and are structurally controlled. The lack of reactive host lithologies may have prevented development of large (> 100 tones of gold), stratigraphically-controlled orebodies, which are typical of the Carlin deposits in the western USA. These deposits are hosted by Triassic turbidities and shallow-water carbonates, and an early Paleozoic inlier in the Songpan-Ganzi basin that extends in an east-west belt for about 300 km. Rather than true "Carlin" deposits, these Carlin-like deposits may be some type of shallow-crustal (i.e., epithermal) hybrid with features intermediate to Nevada-style Carlin deposits and the orogenic gold deposits to the immediate north. These Carlin-like deposits also overlap in age with the early Mesozoic orogenic gold deposits and, therefore, also formed during the final stages of collision between the cratons and intermediate basin closure.

  1. 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

  2. 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…

  3. 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…

  4. Geologic Sequestration of Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Benson, S. M.

    2003-04-01

    Geologic sequestration of carbon dioxide has emerged as one of the most promising options for making deep cuts in carbon dioxide emissions. Geologic sequestration involves the two-step process of first capturing carbon dioxide by separating it from stack emissions, followed by injection and long term storage in deep geologic formations. Sedimentary basins, including depleted oil and gas reservoirs, deep unminable coal seams, and brine-filled formations, provide the most attractive storage reservoirs. Over the past few years significant advances have been made in this technology, including development of simulation models and monitoring systems, implementation of commercial scale demonstration projects, and investigation of natural and industrial analogues for geologic storage of carbon dioxide. While much has been accomplished in a short time, there are many questions that must be answered before this technology can be employed on the scale needed to make significant reductions in carbon dioxide emissions. Questions such as how long must the carbon dioxide remain underground, to what extent will geochemical reactions completely immobilize the carbon dioxide, what can be done in the event that a storage site begins to leak at an unacceptable rate, what is the appropriate risk assessment, regulatory and legal framework, and will the public view this option favorably? This paper will present recent advances in the scientific and technological underpinnings of geologic sequestration and identify areas where additional information is needed.

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

    USGS Publications Warehouse

    Wells, J.D.

    1982-01-01

    The Jabal Riah area is in the southern part of the Jibal al Hamdah quadrangle (lat 19?00'00'' to 19?07'S0'' N., long 45?37'30'' to 43?45'00' E.) in the southeastern Precambrian Shield, Asir Province, Kingdom of Saudi Arabia. The Jabal Mahanid group of ancient gold mines, which is part of the Jabal Ishmas-Wadi Tathlith gold belt, is in the west-central part of the area. Rocks in the Jabal Riah area consist of Precambrian layered metasedimentary and metavolcanic rocks intruded by Precambrian igneous rocks. The metamorphic rocks are, from oldest to youngest, interlayered hornblende and biotite schist, quartz-biotite schist, hornblende schist, serpentinite, and chlorite schist. The igneous rocks are, from oldest to youngest, diorite-gabbro including dikes, granodiorite, monzogranite-granodiorite, leucocratic quartz porphyry, rhyolite, and aplite and pegmatite dikes. A large area of jasper replaces serpentinite. On the valley floors, recent alluvium and pediment deposits overlie the bedrock. The structure of the area is dominated by a dome centered over the eastern border of the area; leucocratic quartz porphyry forms the core of the dome. Minor folds and faults are present. The Jabal Mahanid group of ancient gold mines is on a northwest-trending vein system, and major ancient mine areas are found where the system splits or changes direction. The veins consist of zones of brecciated and crushed rock, which are generally less than 0.5 m wide but may be as wide as 1 m. These zones contain quartz and calcite stringers and commonly are along hornblende schist-serpentinite contacts; however, they also cut both units. Most aplite, pegmatite, and quartz dikes in the area are thin and discontinuous and are intruded along the vein trend. Similar veins, at the same stratigraphic interval, have been found beyond the northeastern part of the map area. The veins contain detectable gold and silver (median gold, approximately 0.14 ppm; median silver, approximately 1 ppm). Gold and 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.

  6. 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.

  7. Hydrothermal alteration in the Mount Hood Area, Oregon. Bulletin

    SciTech Connect

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

    1993-01-01

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

  8. 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.

  9. Southeastern Regional geologic characterization report. Volume 1. Final report

    SciTech Connect

    Not Available

    1985-08-01

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

  10. Classroom Strategies for Introductory Geology.

    ERIC Educational Resources Information Center

    Clemons, Joan

    1991-01-01

    The author describes her use of writing assignments, small-group discussions, note-taking strategies (learning logs), and professional simulations in an introductory geology course. The learning log process consists of note taking on one side of a divided page. After taking notes, students review the notes and record their questions, reactions,

  11. Geological rhythms and cometary impacts

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  12. 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)

  13. 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...

  14. 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...

  15. 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

  16. 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 bedrock exposures on the way to Cape York outcrops. We will report on results from Opportunity's measurements on Victoria, Santa Maria, and Ada craters, together with measurements within Botany Bay, focusing on the synergistic use of Opportunity and CRISM observations to understand the mineralogy and geologic history of Meridiani Planum.

  17. 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.

  18. 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. PMID:11214315

  19. 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.

  20. The Challenges of Standardized Planetary Geologic Mapping

    NASA Astrophysics Data System (ADS)

    Skinner, J. A.

    2015-06-01

    The process and product of creating standardized geologic maps of planetary bodies has been met with particular challenges. Addressing these challenges helps ensure that benchmark contextual geologic map products remain a reliable community resource.

  1. 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.

  2. 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)

  3. 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 fractured, thus more efficient at scattering. Under this hypothesis, all of the water-altered units have significant subwavelength heterogeneity due to their primary mode of origin or secondary alteration. Alternatively, absorption due to the dielectric relaxation of adsorbed water could influence the attenuation. Alteration minerals such as phyllosilicates and palagonite drastically increase the surface area and can hold up to three monolayers of adsorbed water at martian temperatures. Our lab measurements indicate that about 6% phyllosilicates or 15% palagonite by volume can completely attenuate the reflected signal of an interface at a depth of 30 m; which is the shallowest depth SHARAD can detect due to sidelobe effects. These minerals would not be confined to Noachian units as currently suggested by orbital spectroscopy. A smaller proportion of hydrated minerals could be accommodated if the shallow geotherm is steep, or if alteration minerals are below the detection threshold due to their degree of hydration or grain size. In either case, subsurface radar attenuation on Mars is less than that of the Earth, but more than that of the Moon. Tanaka, K.L., J.A. Skinner, and T.M. Hare (2005) Geologic map of the northern plains of Mars, USGS Sci. Invest. Map, 2888.

  4. 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 200 SAUs have been identified within these basins. The results of the assessment are estimates of the technically accessible storage resources based on present-day geological and engineering technology related to CO2 injection into geologic formations; therefore the assessment is not of total in-place resources. Summary geologic descriptions of the evaluated basins and SAUs will be prepared, along with the national assessment results. During the coming year, these results will be released as USGS publications available from http://energy.usgs.gov. In support of these assessment activities, CO2 sequestration related research science is being conducted by members of the project. Results of our research will contribute to current and future CO2 storage assessments conducted by the USGS and other organizations. Research topics include: (a) geochemistry of CO2 interactions with subsurface environments; (b) subsurface petrophysical rock properties in relation to CO2 injection; (c) enhanced oil recovery and the potential for CO2 storage; (d) storage of CO2 in unconventional reservoirs (coal, shale, and basalt); (e) statistical aggregation of assessment results; and (f) potential risks of induced seismicity.

  5. 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.

  6. Computer image processing: Geologic applications

    NASA Technical Reports Server (NTRS)

    Abrams, M. J.

    1978-01-01

    Computer image processing of digital data was performed to support several geological studies. The specific goals were to: (1) relate the mineral content to the spectral reflectance of certain geologic materials, (2) determine the influence of environmental factors, such as atmosphere and vegetation, and (3) improve image processing techniques. For detection of spectral differences related to mineralogy, the technique of band ratioing was found to be the most useful. The influence of atmospheric scattering and methods to correct for the scattering were also studied. Two techniques were used to correct for atmospheric effects: (1) dark object subtraction, (2) normalization of use of ground spectral measurements. Of the two, the first technique proved to be the most successful for removing the effects of atmospheric scattering. A digital mosaic was produced from two side-lapping LANDSAT frames. The advantages were that the same enhancement algorithm can be applied to both frames, and there is no seam where the two images are joined.

  7. 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.

  8. Geological exploration from orbital altitudes

    USGS Publications Warehouse

    Badgley, Peter C.; Fischer, William A.; Lyon, Ronald J. P.

    1965-01-01

    The National Aeronautics & Space Administration is planning geologic exploration from orbiting spacecraft. For that purpose it is evaluating new and refined exploration tools, often called remote sensors, including devices that are sensitive to force fields, such as gravity gradient systems, and devices that record the reflection or emission of electromagnetic energy. Both passive electromagnetic sensors (those that rely on natural sources of illumination, such as the Sun) and active electromagnetic sensors (which use an artificial source of illumination) are being considered.

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 30 CFR 784.22 - Geologic information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., 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. 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, and

  15. 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, and…

  16. Mapping hydrothermal alteration in Yellowstone National Park using magnetic methods

    NASA Astrophysics Data System (ADS)

    Bouligand, C.; Glen, J. M.

    2010-12-01

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

  17. 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.

  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. Geology

    NASA Technical Reports Server (NTRS)

    Arvidson, R.

    1984-01-01

    Three objectives were outlined: (1) global distribution, geometry and composition of continental rock units; (2) morphology and structure of the continental crust; and (3) monitoring selected surface processes. Mapping soil, sediment and rock characteristics for land surfaces requires the use of visible, reflected, thermal and radio parts of the spectrum. Digital topographic data (elevation, slope angle, slope magnitude) are needed to correct reflectance, emission, and radar data. In addition, images of the topographic data provide fundamental information on the morphology and structure of the land.

  20. 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.

  1. 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.

  2. 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 potential for enhanced coal bed methane recovery (ECBM).

  3. 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 quadrangle. They deserve detailed surface investigation followed if needed by exploration at depth.

  4. 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.

  5. 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.

  6. 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. PMID:17777763

  7. Geological rhythms and cometary impacts

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  8. United States Geological Survey yearbook

    SciTech Connect

    Not Available

    1988-01-01

    This yearbook of the U.S. Geological Survey describes results of a number of USGS research efforts in such diverse areas as studying the quality of the nation's surface-and ground-water resources, assessing the nation's oil and gas resources, and applying cartographic and remote sensing techniques to aid legislators, policymakers, and the public in solving land-and resources-management problems. Specific issues discussed in this yearbook include erosion of Louisiana's coastal barrier islands, transport of pollutants in sediment in the Mississippi River, primary mapping economic analysis, and probabilities of large earthquakes in California.

  9. Applications of ISES for geology

    NASA Technical Reports Server (NTRS)

    Bowker, David E.

    1990-01-01

    The principal applications for onboard data processing and real-time data transmission in the geological sciences are the detection of early warning signs of potential catastrophic events and the rapid assessment of impact and damage following major events. Also, the opportunity for quick look and supporting data during field investigations should not be disregarded. The Eos platforms are ideal for these applications because of the variety of earth sensing instruments and their differing modes of operation. Further study is required to define the role for each instrument and to assess how they can aid each other in establishing an improved output product.

  10. 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.

  11. Measuring student understanding of geological time

    NASA Astrophysics Data System (ADS)

    Dodick, Jeff; Orion, Nir

    2003-09-01

    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, and evolutionary biology. Thus, any student that wants to master these subjects must have a good understanding of geological time. Despite its critical importance, there has been very little attention given to geological time by science education researchers. Of the work that has been done, much of it ignores the cognitive basis for students' understanding of geological time. This work addresses this gap by presenting a validation study for a new instrument - the GeoTAT (Geological Time Aptitude Test). Consisting of a series of open puzzles, the GeoTAT tested the subjects' ability to reconstruct and represent the transformation in time of a series of geological structures. Montagnero (1992, 1996) terms this ability diachronic thinking. This instrument was distributed to a population of 285 junior and senior high school students with no background in geology, as well as 58 high school students majoring in geology. A comparison of the high school (grades 11-12) geology and non-geology majors indicated that the former group held a significant advantage over the latter in solving problems involving diachronic thinking. This relationship was especially strengthened by the second year of geological study (grade 12), with the key factor in this improvement being exposure to fieldwork. Fieldwork both improved the subjects' ability in understanding the 3-D factors influencing temporal organization, as well as providing them with experience in learning about the types of evidence that are critical in reconstructing a transformational sequence.

  12. Elements of Australian petroleum geology

    SciTech Connect

    Masters, C.D.; Scott, E.W.

    1986-05-01

    The petroleum geology of Australia reflects the existence of a large cratonic block broken away from India and Antarctica in the early Mesozoic and early Tertiary that has resulted in a rifted passive-margin character on the northwestern, western, and southern boundaries of the continent. Pre-breakup paleozoic sediments are widely distributed but commonly not deeply buried nor particularly thick, and hence contribute minimally to petroleum resource occurrence. Like their Asian neighbors, much of Australian petroleum geology is nonmarine and associated with marginal rift basins. The small Gippsland basin on the southeastern coast, which is responsible for more than 90% of oil and 28% of the gas discovered in Australia, derives its petroleum from nonmarine Eocene to Cretaceous graben-fill sediments, sealed and buried by Oligocene marine shales. The most active play in Australia is in the Eromanga depression of the Great Artesian basin, where nonmarine oil is trapped stratigraphically in small fields in Jurassic and Cretaceous sandstones. These Mesozoic sediments are sag-fill deposits above the Permian-Triassic Cooper basin, and are responsible for some 12% of the gas reserves in Australia. Offshore of the western coast, graben basins filled with late Paleozoic to Mesozoic sediments are prolific and gas-prone - 55% of reserves - owing to coaly source rocks. North Sea-type, Upper Jurassic grabens off the northwestern coast of Australia contain Kimmeridgian hot shales, but developmental drilling, following the initial Jabiru discovery, has yet to demonstrate large reserves.

  13. Computer stereograms of subsurface geology

    SciTech Connect

    Todd, H.W.

    1988-01-01

    Three-dimensional stereoscopic illustrations formerly have been a standard part of the subsurface geologist's toolkit. Now the immense complexity of stereograms can be resolved by inexpensive software on a personal computer. The construction technique is a simple combination of known technology. The subsurface geologist can gain an entirely new viewpoint. These new illustrations yield new patterns, new relationships, and prospective anomalies. Stereograms are particularly effective for displaying and interpreting complex geology in a simple way. Experienced geologists sometimes can fail to appreciate the vertical relationships involved in contour maps. Stereograms provide a more natural view of the data. They are useful also for presenting subsurface geology to persons unfamiliar with standard contouring methods and for clarifying vertical relationships to more experienced viewers. Contour maps and block diagrams were constructed with readily available, inexpensive software using kriging algorithms. Stereo pairs were created by rotating the blocks 4 degrees within the computer program. The pairs were positioned 2.5 in. apart to match an average viewer's interpupillary distance. The three-dimensional blocks may be viewed with a stereoscope or with naked eyes focused upon a distant point.

  14. 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.

  15. 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

    The age of the major geological units in Japan ranges from Cambrian to Quaternary. Precambrian basement is, however, expected, as the provenance of by detrital clasts of conglomerate, detrital zircons of metamorphic and sedimentary rocks, and as metamorphic rocks intruded by 500 Ma granites. Although rocks of Paleozoic age are not widely distributed, rocks and formations of late Mesozoic to Cenozoic can be found easily throughout Japan. Rocks of Jurassic age occur mainly in the Jurassic accretionary complexes, which comprise the backbone of the Japanese archipelago. The western part of Japan is composed mainly of Cretaceous to Paleogene felsic volcanic and plutonic rocks and accretionary complexes. The eastern part of the country is covered extensively by Neogene sedimentary and volcanic rocks. During the Quaternary, volcanoes erupted in various parts of Japan, and alluvial plains were formed along the coastlines of the Japanese Islands. These geological units are divided by age and origin: i.e. Paleozoic continental margin; Paleozoic island arc; Paleozoic accretionary complexes; Mesozoic to Paleogene accretionary complexes and Cenozoic island arcs. These are further subdivided into the following tectonic units, e.g. Hida; Oki; Unazuki; Hida Gaien; Higo; Hitachi; Kurosegawa; South Kitakami; Nagato-Renge; Nedamo; Akiyoshi; Ultra-Tamba; Suo; Maizuru; Mino-Tamba; Chichibu; Chizu; Ryoke; Sanbagawa and Shimanto belts. The geological history of Japan commenced with the breakup of the Rodinia super continent, at about 750 Ma. At about 500 Ma, the Paleo-Pacific oceanic plate began to be subducted beneath the continental margin of the South China Block. Since then, Proto-Japan has been located on the convergent margin of East Asia for about 500 Ma. In this tectonic setting, the most significant tectonic events recorded in the geology of Japan are subduction-accretion, paired metamorphism, arc volcanism, back-arc spreading and arc-arc collision. The major accretionary 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.

  16. 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).

  17. 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.

  18. 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 shards, which compacted and welded into thick massive units during emplacement and cooling. Subordinate water-laid clastic rocks occur t(ward the top of the formation, and thin-bedded pyroclastic layers occur between some of the ash flows. Exposures on Backbone Ridge and on Carbon River below the mouth of Cataract Creek show that in places the thick basal Stevens Ridge ash flows swept with great violence over an old erosion surface developed on rocks of the Ohanapecosh Formation. Masses of mud, tree trunks, and other surface debris were swirled upward into the base of the lowermost ash fiery, and lobes and tongues of hot ash were forced downward into. the saprolitic mud. The Stevens Ridge Formation is concordantly overlain by the Fifes Peak Formation of probable early Miocene age, which consists of lava flows, subordinate mudflows, and minor quantities of tuffaceous clastic rocks. The lavas are predominantly olivine basalt and basaltic andesite, but they include a little rhyolite. They are slightly to moderately altered: the ferromagnesian phenocrysts are generally replaced by saponite, chiprite, or carbonate ; the glass is devitrified ; and the rocks are locally permeated by veinlets of zeolite. Swarms of diabase sills and dikes are probably intrusive equivalents of the Fifes Peak lavas. The upper part of the Fifes Peak Formation has been mostly eroded from Mount Rainier National Park, but farther north, in the Cedar Lake quadrangle, it attains a thickness of more than 5,000 feet. The Fifes Peak and earlier formations were gently folded, faulted, uplifted, and eroded before the. late Miocene Tatoosh pluton worked its way upward to shallow depths and eventually broke through to the surface. The rise of the pluton was accompanied by .the injection of a complicated melange of satellitic stocks, sills, and dikes. A favored horizon for intrusion of sills was along or near the unconfo

  19. Introduction: The Geologic Mapping of Vesta

    NASA Technical Reports Server (NTRS)

    Williams, David A.; Yingst, R. Aileen; Garry, W. Brent

    2014-01-01

    The purpose of this paper is to introduce the Geologic Mapping of Vesta Special Issue/Section of Icarus, which includes several papers containing geologic maps of the surface of Vesta made to support data analysis conducted by the Dawn Science Team during the Vesta Encounter (July 2011-September 2012). In this paper we briefly discuss pre-Dawn knowledge of Vesta, provide the goals of our geologic mapping campaign, discuss the methodologies and materials used for geologic mapping, review the global geologic context of Vesta, discuss the challenges of mapping the geology of Vesta as a small airless body, and describe the content of the papers in this Special Issue/Section. We conclude with a discussion of lessons learned from our quadrangle-based mapping effort and provide recommendations for conducting mapping campaigns as part of planetary spacecraft nominal missions.

  20. Introduction: The geologic mapping of Vesta

    NASA Astrophysics Data System (ADS)

    Williams, David A.; Yingst, R. Aileen; Garry, W. Brent

    2014-12-01

    The purpose of this paper is to introduce the Geologic Mapping of Vesta Special Issue/Section of Icarus, which includes several papers containing geologic maps of the surface of Vesta made to support data analysis conducted by the Dawn Science Team during the Vesta Encounter (July 2011-September 2012). In this paper we briefly discuss pre-Dawn knowledge of Vesta, provide the goals of our geologic mapping campaign, discuss the methodologies and materials used for geologic mapping, review the global geologic context of Vesta, discuss the challenges of mapping the geology of Vesta as a small airless body, and describe the content of the papers in this Special Issue/Section. We conclude with a discussion of lessons learned from our quadrangle-based mapping effort and provide recommendations for conducting mapping campaigns as part of planetary spacecraft nominal missions.

  1. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  3. 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.

  4. Objective Subsurface Geological Modeling using Geological Columns - A case study for the Kisarazu Distinct, Japan

    NASA Astrophysics Data System (ADS)

    Nonogaki, S.; Nakazawa, T.

    2013-12-01

    Geological models of subsurface structure play an important role in disaster assessment, environmental preservation, and underground utilization. These models are often constructed subjectively based on geological data obtained from field survey. However, reliability of subjective model depends on modeler's knowledge and experience as well as on quality of basic data. In order to ensure a more stable reliability of the model, objective approach is necessary. The purpose of this study is to establish an objective geological modeling method. For the purpose of this study, we constructed a subsurface geological model focusing on mathematical treatment of stratigraphy. Study area is the Kisarazu distinct, in the middle part of Chiba Prefecture, Japan. Basic data for modeling are 44 geological columns. In the modeling, firstly, we constructed a Logical Model of Geological Structure (LMGS) that defines a positional relation between geological boundary surfaces and geological units. The LMGS is objectively given by recurrence formula derived from a sequence of geological events arranged in chronological order. Secondly, we generated Digital Elevation Models (DEMs) of geological boundary surfaces using geological columns. Thirdly, we constructed an objective geological model using the LMGS and the DEMs. Finally, we visualized the model in 2D and 3D using GRASS GIS. As a result, in the areas with high number of geological columns, geological map and geological cross-sections derived from objective model were in good agreement with the ones derived from subjective model reported in other studies. In the areas with low number of geological columns, the objective map and cross-sections were somewhat different from subjective ones. In conclusion, the results indicate that objective model may give new findings about subsurface structure. In addition, the objective model gives a more stable reliability than the subjective model because the former ensures traceability of modeling procedures. The LMGS is unfit for complicated geological structures like lens. For the solution of this problem, we need to improve theoretical base of the LMGS.

  5. 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.

  6. 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]).

  7. Europa: Geological activity and surface - subsurface exchange

    NASA Astrophysics Data System (ADS)

    Phillips, C. B.; Cowell, W.

    2005-12-01

    Jupiter's moon Europa has a geologically young surface, allowing the possibility of current, ongoing geological activity. We are searching the Galileo database for overlapping images taken during the 5-year mission, and are comparing images using an iterative coregistration technique to look for changes due to geological activity. We will also discuss methods by which such activity could occur on Europa. We are particularly interested in the ability of geological processes to bring surface material down into the subsurface, and to bring subsurface material up to the surface. We are continuing a survey of such processes, including endogenic tectonic and cryovolcanic activity, and exogenic processes such as gardening and impact cratering.

  8. 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.

  9. 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.

  10. 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.

  11. Geological interpretation of potential fields

    NASA Astrophysics Data System (ADS)

    Starostenko, V. I.

    This volume contains papers from the Third All-Union School-Seminar on the Geological Interpretation of Gravitational and Magnetic Fields (Yalta, December 1980). Particular consideration is given to such topics as a method for constructing density models of the tectonosphere of platform and active regions; the interpretation of the gravitational field of the basic structures of the world ocean; the current status of gravitational surveying; and an algorithm for the regional interpretation of gravimetry data. Also considered are the inverse problem of magnetic surveying; the role of viscous magnetization in the formation of magnetic anomalies of the continental crust; calculation of mechanical stresses in the lithosphere on the basis of gravitational data; the deep structure of the Siberian platform as interpreted on the basis of gravimeter and magnetometer data; the equivalence of density models of deep structures; and a systems approach to the interpretation of gravimetry data. No individual items are abstracted in this volume

  12. 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.

  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. Report on geologic exploration activities

    SciTech Connect

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

    1980-01-01

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

  15. Report on geologic exploration activities

    SciTech Connect

    1980-01-01

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

  16. 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.

  17. 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 structures: A limited set of material units and tectonic structures describes the geological situation on the surface of Venus (Fig. 1). The globally applicable stratigraphic sequence summarizing varieties of local to regional columns consists of the following units (from older to younger), the relative ages of which are established by relationships of embayment: Tessera (t) represents elevated regions deformed by multiple sets of tectonic structures. Densely lineated plains (pdl) are dissected by numerous subparallel narrow and short lineaments. Ridged plains (pr) commonly form elongated belts of ridges. Shield plains (psh) have numerous small volcanic edifices on the surface. Regional plains were divided into the lower (pr1) and the upper (pr2) units. The lower unit has uniform and relatively low radar albedo; the upper unit is brighter and often forms flow-like occurrences. Shield clusters (sc) are morphologically similar to psh but occur as small patches that postdate regional plains. Smooth plains (ps) have uniform and low radar albedo and occur near impact craters and at distinct volcanic centers. Lobate plains (pl) form fields of lava flows that are typically undeformed by tectonic structures and are associated with major volcanic centers. Several structural assemblages complicate the surface of the material units: Tessera-forming structures (ridges and grooves), belts of ridges, belts of grooves (structural unit gb), mountain belts (structural unit mt that occurs around Lakhmi Planum), wrinkle ridges, and rift zones (structural unit rt). The higly tectonized material and structural units such as t, pdl, pr, mt, and gb predate vast plains units such as psh and rp1. Wrinkle ridges deform all units that are older than units ps and pl. Smooth and lobate plains together with rift zones and shield clusters appear to be contemporaneous and form the top of the global stratigraphic column. Crater statistics: Two factors, the atmosphere screening [32-34] and the observational bias [35], appear to affect the statistics of the smaller craters on Venus. For the larger crater

  18. Geologic stereo mapping of geologic structures with SPOT satellite data

    SciTech Connect

    Berger, Z. ); Williams, T.H.L. ); Anderson, D.W. )

    1992-01-01

    The SPOT imaging system, launched in 1986 by the French National Space Agency (CNES), provides two significant advances for mapping geological structures from satellite imagery: increased spatial resolution of key structural and stratigraphic elements, and stereoscopic capabilities for making strike-and-dip measurements. Quantitative stereo mapping with SPOT data may be done using hard-copy images and conventional equipment, such as stereo plotters, or by displaying images on a video monitor in stereo-viewing format. The latter method is a new remote-sensing technique particularly relevant to the exploration community. This technique allows development, with minor expenditure and training, of an effective stereo mapping capability on existing image-processing systems or on stand-alone personal computers. SPOT stereo data is particularly useful for mapping low-amplitude and highly deformed structures. Surface structure maps generated from stereo imagery data can be applied to exploration at two levels. At early stages, such maps can be used to establish the style, trend, size, and spatial distribution of structures in a basin, and to investigate key tectonic elements. At more advanced prospecting stages, these maps can be used to constrain subsurface mapping of structures located in areas of poor seismic data quality. This latter technique, however, may require the support of higher resolution stereo aerial photography.

  19. 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)

  20. 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.

  1. 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

  2. Advances in planetary geology, volume 2

    SciTech Connect

    Not Available

    1986-07-01

    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.

  3. 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.

  4. Integration of geologic interpretation into geostatistical simulation

    SciTech Connect

    Carle, S.F.

    1997-06-01

    Embedded Markov chain analysis has been used to quantify geologic interpretation of juxtapositional tendencies of geologic facies. Such interpretations can also be translated into continuous-lag Markov chain models of spatial variability for use in geostatistical simulation of facies architecture.

  5. 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.

  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. 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.

  8. 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.

  9. 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.

  10. 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 degraded and fresh sharp craters. Preliminary crater counts indicate only small differences in absolute surface model ages between the northern region and the south polar structure.

  11. 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. PMID:21808092

  12. 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 ...

  13. 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.

  14. Geologically based fractured reservoir simulator

    SciTech Connect

    Wolff, M.

    1987-01-01

    The purpose of this study is to investigate flow of fluids in naturally fractured systems. Fracture networks are simulated using stochastically distributed variables to generate realistic random networks of interconnected planar flow paths. The network model is based on geological observations of actual fracture networks in sedimentary rocks. Network volumes, directional permeabilities, and breakthrough times and curves are generated for various flow geometries through computer simulation. A study is then conducted to relate these various results to variations in network parameters. Another simulator is written to model the behavior of individual matrix blocks during a water flood of the fracture network. Countercurrent imbibition causes oil to be fed into the fractures from the matrix. Specific oil feed functions are derived for rectangular matrix blocks with rock parameters from the Spraberry formation of West Texas. These feed functions are combined with the fracture network simulator and realistic networks with Spraberry network and rock parameters are simulated. Results indicate that while fractures provide the flow paths for the water flood, matrix block inhibition characteristics control breakthrough times and overall recovery.

  15. Global Warming in Geologic Time

    ScienceCinema

    David Archer

    2010-01-08

    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.

  16. Antarctica: geology and hydrocarbon potential

    SciTech Connect

    St. John, B.

    1984-09-01

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

  17. 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.

  18. (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.

  19. Pennsylvania's contribution to petroleum geology

    SciTech Connect

    Dickey, P.A.

    1991-03-01

    The petroleum industry began on August 27, 1859, with the drilling of the Drake well at Titusville, Pennsylvania. The well was located on an oil seep. Since then, most of the great oil provinces of the world have been located on or downdip from seeps. The next prospecting method was to note the orientation of productive trends, still universally used. The anticlinal theory was proposed in 1861, but not of the great Pennsylvania oil fields is on anticlines, so their importance was not generally recognized in the industry until the discovery of Cushing, Oklahoma, in 1912. John F. Carll, the oil geologist of the Pennsylvania Geological Survey between 1874 and 1888, introduced the techniques of logging samples, correlating strip logs, and drawing structure contours. He recognized that the oil came from porous sands, probably laid down nearshore. He recognized that gas was dissolved in the oil and understood water drive. In the 1920s, and 1930s, researchers at Penn State and at Gulf in Pittsburgh took cores, defined porosity, permeability, and relative permeability, and laid the foundations of reservoir behavior. The University of Pittsburgh started the first oil and gas curriculum in 1912.

  20. 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.

  1. 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.

  2. 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

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

  4. Kimberlite wall-rock fragmentation processes: Venetia K08 pipe development

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

    Current kimberlite pipe development models strongly advocate a downward growth process with the pipe cutting down onto its feeder dyke by means of volcanic explosions. Evidence is presented from the K08 kimberlite pipe in Venetia Mine, South Africa, which suggests that some pipes or sub-components of pipes develop upwards. The K08 pipe in pit exposure comprises >90 vol.% chaotic mega-breccia of country rock clasts (gneiss and schist) and <10 vol.% coherent kimberlite. Sub-horizontal breccia layers, tens of metres thick, are defined by lithic clast size variations and contain zones of shearing and secondary fragmentation. Textural studies of the breccias and fractal statistics on clast size distributions are used to characterize sheared and non-sheared breccia zones and to deduce a fragmentation mechanism. Breccia statistics are compared directly with the statistics of fragmented rock produced from mining processes in order to support interpretations. Results are consistent with an initial stage of brecciation formed by upward-moving collapse of an explosively pre-conditioned hanging wall into a sub-terranean volcanic excavation. Our analysis suggests that the pre-conditioning is most likely to have been caused by explosions, either phreatic or phreatomagmatic in nature, with a total energy output of 2.7 × 109 kJ (656 t of TNT). A second stage of fragmentation is interpreted as shearing of the breccia caused by multiple late kimberlite intrusions and possible bulk movement of material in the pipe conduit related to adjacent volcanism in the K02 pipe.

  5. 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.

  6. 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 -216'33", Longitude -510'51"). 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.

  7. 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., Jr.; 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.

  8. 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.

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

    SciTech Connect

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

    1980-01-01

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

  10. 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 in the form of tectonics and cryo-volcanism.

  11. 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 prospects for endogenic activity in the form of tectonics and cryovolcanism.

  12. 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.

  13. 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.

  14. The Mekong at climatic crossroads: Lessons from the geological past.

    PubMed

    Penny, Dan

    2008-05-01

    The wetlands of the lower Mekong River Basin are ecologically and socioeconomically significant, but they are threatened by predicted climatic change. The likely response of wetland ecosystems to altered flooding regimes and surface-water chemistry is unknown in detail and difficult to model. One way of exploring the impact of climate change on wetland ecosystems is to utilize proxy environmental data that reveal patterns of change over geological time. In recent years, the coverage and resolution of proxy climatic data have improved markedly in the region. Recent evidence of the South China Sea transgression into southern and central Cambodia and paleobotanical evidence from the Tonle Sap ("Great Lake") and elsewhere allow us to explore how periods of higher-than-present sea level and increased monsoon rainfall in the past have impacted the wetland ecology of the lower Mekong River Basin. PMID:18595270

  15. 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.

  16. 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.

  17. Geologic exploration of solar system

    SciTech Connect

    Wood, C.A.

    1987-11-01

    The processes that must have operated on the early Earth have been deduced from evidence from ancient surfaces of the Moon and planets. In particular, such comparative studies have demonstrated that only two geologic processes have been widespread throughout the history of the solar system: impact cratering and volcanism. Impact craters have formed throughout solar system history, indeed the planets themselves were formed by the accumulation of millions of smaller planetesimals, each of which formed an impact crater. Earth could not have escaped the intense bombardment that churned the surfaces of Mars, Mercury, and the Moon. The impact cratering rate dramatically declined about 3.9 billion years ago, but craters 10 km across still form on the Earth on the average of one every 140,000 years, and the 1.5-km wide Meteor Crater in Arizona formed only about 25,000 years ago. Volcanic flows and cones have been observed on nearly all planets and moons in the solar system; the variety and duration of volcanism are directly related to planet mass. Thus, a relatively large planet like the Earth has a wide range of volcanic morphologies and compositions, with activity continuing throughout Earth history. In contrast, the smaller Moon produced a narrow compositional range of basaltic lava flows, with most of the lavas having erupted about 3 billion years ago. Water and sulfur volcanism have also been discovered on the cold satellites of the outer solar system, thus expanding their terrestrial concept of volcanism. Many other processes and materials exist in the solar system, but the Earth remains unique in its richness of resources to support humans. Discovery and exploitation of extraterrestrial resources are beginning and must be greatly increased to prepare for their future as a space-faring race.

  18. 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.

  19. 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)

  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 six possible Martian landing sites

    NASA Technical Reports Server (NTRS)

    Masursky, Harold; Dial, A. L., Jr.; Strobell, M. E.; Applebee, D. J.

    1987-01-01

    Thirteen detailed maps of the first six (of ten) possible sites for a future Lander/Rover/Sample-return mission to Mars are either nearing completion or in review. Basic mosaic of all sites were available at 1:2 million scale. In addition to preparing new base maps, special enhancements were generated for computer mosaics and individual images that delineate the geologic units more clearly. Photoclinometric profiles that allowed measurement of the thicknesses of geologic units, the depth of channels, and the throw on faults were prepared. Crater counts were made for each geologic unit.

  2. Mountains and plains Denver's geologic setting

    USGS Publications Warehouse

    U.S. Geological Survey

    1967-01-01

    A slice of geologic history is exposed to view in the Denver, Colorado area. Denver is situated on the High Plains near the east front of the Rocky Mountains. As one travels westward from Denver toward the mountains, successively older rocks are crossed from the geologically young rocks of the High Plains and the South Platte River valley to the older rocks of the foothills and the ancient rocks of the mountains. Thus, within a few miles,the journey turns back the pages of time in a lifesized textbook that vividly illustrates the geologic events that shaped the landscape.

  3. Developing Medical Geology in Uruguay: A Review

    PubMed Central

    Maay, 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 populations 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

  4. Revised draft: Southeastern Regional geologic characterization report. Volume 1

    SciTech Connect

    Not Available

    1984-11-01

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

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

    SciTech Connect

    Not Available

    1984-11-01

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

  6. Long-term Alteration of Fractured Glass Blocks in Seawater

    NASA Astrophysics Data System (ADS)

    Verney-Carron, A.; Gin, S.; Libourel, G.

    2007-12-01

    Fractured archaeological glass blocks, altered in seawater over 1800 years, are studied because of their morphological analogy with the industrial nuclear glass blocks. They represent a striking example of altered fractured glass on a representative timescale in the prospect of a deep geological repository. Thus, they may contribute to the validation of models devoted to assess the long-term behaviour of high-level waste glass. Here, we present results concerning the alteration mechanisms within the cracks and the influence of seawater transport parameters on these mechanisms. A detailed study of the morphology, mineralogy and chemistry of these blocks allows to see that the alteration thicknesses of internal cracks are thinner than the alteration at the periphery of blocks (1 or 2 orders of magnitude). It suggests that the contribution of internal cracks to global alteration is quite low and that alteration processes depend on the renewal rate of the solution within cracks, so on the aperture and the accessibility to water. We also show that two mechanisms are involved in the glass alteration: i) interdiffusion between glass alkalis and protons of the solution leading to an amorphous gel layer, and ii) glass network dissolution followed by precipitation of less soluble elements of the glass (Si, Al) and some elements of the seawater (Mg) resulting in the formation of a secondary phases layer (smectites) in the middle of the crack. It is of note that the influence of transport parameters causes differences in the contribution of both mechanisms and in their respective kinetics. Indeed, at the periphery of blocks, alteration layers are thick and composed mainly of secondary products, because dissolution is maximal when solution is highly renewed. On the contrary, in cracks, where transport is slow, local equilibrium of saturation (Si) seems to be established quickly, creating favourable conditions to a drop in the dissolution rate. It causes a relative increase of the contribution of interdiffusion. Besides, the sealing due to the precipitation of secondary phases accentuates this influence of transport in cracks. To understand the coupling between chemistry and transport better, mainly the influence of parameters, such as aperture or S/V ratio, on the alteration kinetics, experiments have been carried out. Results show that thinner the fracture, higher pH, which reduces the diffusion coefficient of alkalis, and faster the chemical saturation is reached. These experimental data aim at parametering a model of a fractured glass block alteration.

  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 the aqueous alteration of lunar materials and simulants (e.g., Keller and Huang, 1971; Eick et al., 1996). Lunar basalts are void of water and highly reduced, hence, these materials are initially very reactive when exposed to water under oxidizing conditions.

  8. 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.

  9. 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)

  10. Remote-sensing applications to geology

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Results of two day workshop on applications of remote sensing to geology are summarized in report. Topics discussed are environmental analysis, crop classification, plant epidemics and diseases, irrigation reform, and soil surveys.

  11. Geological Survey research 1971, Chapter D

    USGS Publications Warehouse

    U.S. Geological Survey

    1971-01-01

    Chapter A, to be published later in the year, will present a summary of significant results of work done in fiscal year 197, together with lists of investigations in progress, reports published, cooperating agencies, and Geological Survey offices.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. OneGeology: Making the Worlds Geological Map Data Accessible Online

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    OneGeology (http://onegeology.org) is a successful international initiative of the geological surveys of the world and the flagship project of the International Year of Planet Earth. Its aim is to provide dynamic web access to geological map data covering the world, creating a focus for accessing geological information for everyone. Thanks to the enthusiasm and support of participating nations the initiative has progressed rapidly and geological surveys and the many users of their data are excited about this ground-breaking project. Currently 10 international geoscience organizations have endorsed the initiative and more than 109 countries have agreed to participate. OneGeology works with whatever digital format is available in each country. The target scale is 1:1 million, but the project is pragmatic and accepts a range of scales and the best available data. The initiative recognizes that different nations have differing abilities to participate and transfer of know-how to those who need it is a key aspect of the approach. A key contributor to the success of OneGeology has been its utilization of the latest new web technology and an emerging data exchange standard for geological map data called GeoSciML. GeoSciML (GeoScience Markup Language) is a schema written in GML (Geography Markup Language) for geological data. GeoSciML has the ability to represent both the geography (geometries e.g. polygons, lines and points) and geological attribution in a clear and structured format. OneGeology was launched March 2007 at the inaugural workshop in Brighton England. At that workshop the 43 participating nations developed a declaration of a common objective and principles called the Brighton Accord (http://onegeology.org/what_is/accord.html) . Work was initiated immediately and the resulting OneGeology Portal was launched at the International Geological Congress in Oslo in August 2008 by Simon Winchester, author of The Map that Changed the World. Since the successful launch, OneGeology participants have continued working both to increase national participation and content, and to put in place a more formal governance structure to oversee the long term evolution of the initiative. OneGeology is an example of collaboration in action and is both multilateral and multinational. In 2007, a group of motivated geoscientists and data managers identified an opportunity and took the initiative to engage their peers to work in concert to achieve a shared objective. OneGeology has facilitated collaborative development of an Internet site that provides unprecedented online access to global geological map data.

  17. 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.

  18. 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+

  19. 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.

  20. 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.

  1. 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.

  2. 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 geological data. These datasets are registered in a multilingual catalogue, who is one the main part of this system. This catalogue and a common metadata profile allows the discovery of national geological and applied geological maps at all scapes, Such an architecture is facilitating re-use and addition of value by a wide spectrum of users in the public and private sector and identifying, documenting and disseminating strategies for the reduction of technical and business barriers to re-use. In identifying and raising awareness in the user and provider communities, it is moving geological knowledge closer to the end-user where it will have greater societal impact and ensure fuller exploitation of a key data resource gathered at huge public expense. The project is providing examples of best practice in the delivery of digital geological spatial data to users, e.g. in the insurance, property, engineering, planning, mineral resource and environmental sectors. The scientifically attributed map data of the project will provide a pan-European base for science research and, importantly, a prime geoscience dataset capable of integration with other data sets within and beyond the geoscience domain. This presentation will demonstrate the first results of this project and will indicate how OneGeology-Europe is ensuring that Europe may play a leading role in the development of a geoscience spatial data infrastructure (SDI) globally.

  3. Geologic reconnaissance in western Liberia

    USGS Publications Warehouse

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

    1967-01-01

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

  4. 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.

    2016-01-01

    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 Orogeny. Surface exposure and weathering of fluorapatite produced acidic fluids and intense, near-surface kaolinitised zones that include high-grade, supergene-enriched cheralite-rich ores.

  5. 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 that is much more complex than previously described.

  6. WIPP site and vicinity geological field trip

    SciTech Connect

    Chaturvedi, L.

    1980-10-01

    The Environmental Evaluation Group (EEG) is conducting an assessment of the radiological health risks to people from the Waste Isolation Pilot Plant (WIPP). As a part of this work, EEG is making an effort to improve the understanding of those geological issues concerning the WIPP site which may affect the radiological consequences of the proposed repository. One of the important geological issues to be resolved is the timing and the nature of the dissolution processes which may have affected the WIPP site. EEG organized a two-day conference of geological scientists, titled Geotechnical Considerations for Radiological Hazard Assessment of WIPP on January 17-18, 1980. During this conference, it was realized that a field trip to the site would further clarify the different views on the geological processes active at the site. The field trip of June 16-18, 1980 was organized for this purpose. This report provides a summary of the field trip activities along with the participants post field trip comments. Important field stops are briefly described, followed by a more detailed discussion of critical geological issues. The report concludes with EEG's summary and recommendations to the US Department of Energy for further information needed to more adequately resolve concerns for the geologic and hydrologic integrity of the site.

  7. Canadian foothills geology unraveled by VSPs

    SciTech Connect

    Van Dijk, A.A.; Amstutz, R. )

    1992-07-01

    This paper reports that downhole vertical seismic profiles (VSPs) can help improve confidence in a seismic interpretation when surface seismic data are poor and the local geology is complex. Improved siting of additional drilling locations can result. In the case study detailed, Paleozoic outcrops at a prospective Alberta Foothills location caused the surface seismic data obtained to be a very poor representation of the subsurface. To gain needed subsurface detail, the operator chose to acquire a VSP survey in an initial wellbore in the area. Briefly, steps in the survey included: building an initial geologic model from the surface seismic in hand and limited local geologic knowledge; drilling a prospect well based on the initial geologic model; acquiring one VSP pass prior to reaching TD to locate a major fault and optimize the second VSP pass; process the first VSP pass and reinterpret the surface seismic based on the direct arrivals obtained from the VSP; modify the geologic model; acquire a second VSP pass optimized over the zones of interest; process the second VSP pass and overlay it on the reinterpreted surface seismic for further refinement and agreement; modify the geologic model and pick further drilling sites.

  8. Geologic studies in Alaska by the U.S. Geological Survey, 1998

    USGS Publications Warehouse

    Kelley, Karen D., (Edited By); Gough, Larry P.

    2000-01-01

    This annual compilation of geologically related papers, all dealing with studies in Alaska, contains 16 reports divided among four topics: geologic framework, environment and climate, resources, and bibliographies. These topics reflect the scope and objectives of some currently active U.S. Geological Survey programs and projects from all parts of the State of Alaska. Studies include results from the natural, chemical, and physical Earth sciences and are of interest to academia, government, industry, and the general public.

  9. 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 at Yucca Mountain, Nevada, USA. These results generally bracket repository conditions between natural and experimental systems providing confidence in the understanding of expected processes. Also, the conceptual bases and numerical techniques for modeling unsaturated zone contaminant transport over periods of thousands of years at Yucca Mountain were tested by modeling the observable record of metal transport from archaeological artifacts buried in Holocene tuff at Akrotiri, Greece. Geologically episodic mineral alteration and contaminant transport have been documented using radioisotope data in numerous analog systems providing insights for the interpretation and validity of predictive models for long term repository performance. The applicability and value of natural analog studies to understanding geologic disposal systems is a persistent question. As proposed disposal sites become increasingly well defined by site characterization and engineering design, the strengths and weaknesses of analogies can be assessed. Confidence in predictive models for complex geologic and engineered phenomena can be enhanced through multiple lines of investigation including studies of natural analog systems.

  10. 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 Geological Survey (CGS) working with the Bureau de Recherches Géologiques et Minières (BRGM), the British Geological Survey (BGS), the Geological Survey of Denmark and Greenland (GEUS) and the Geological Survey of Slovenia (GeoZS). The Geological Survey of the Netherlands (TNO) decided to provide financial support for the initiative. The Technical Support Team has been providing the technical advice required to enable the inclusion of geological maps from new countries in the 1G-E Portal using the standards developed and accepted for 1G-E. Cookbooks, on-line help and a helpdesk are provided during the work. A technical workshop was organized at which all the technical steps required to reach the target solution were presented and discussed. All newcomers must agree the existing common license that was created for downloading the 1G-E data. It should be emphasized that the results will be displayed as part of the 1G-E project and metadata/portal infrastructures. The process is still ongoing because the harmonization work for most of the countries involved has been a demanding process. Some countries are facing difficulties because of the lack of expert personnel or insufficient resources of data. Despite some problems, the 1G-E+ initiative and the work involved has contributed to effective networking and technical cooperation between the GSOs across the wider European region.

  11. 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 the resulting time-stratigraphic system and geologic timescale. Key results from the geologic mapping of Vesta include: 1) surface units are dominated by features and materials produced by two major impact events, the older Veneneia and younger Rheasilvia impacts at the south pole 2) both impacts produced a ridge-and-trough terrain as a tectonic response to the impacts, mapped as the Saturnalia Fossae and the Divalia Fossae Formations, respectively 3) stratigraphic analysis of Vesta's heavily cratered terrains show that portions of the original crust are preserved and predate the Veneneia impact 4) the Marcia impact event marks the beginning of Vesta's final stratigraphic period, including exposure of fresh bright and dark material and preservation of young bright-rayed and dark-rayed craters. We conclude that a geologic mapping campaign, including both global and regional mapping, can be conducted during the limited planetary nominal mission timeline, and is an excellent way to engage younger team members (graduate students and postdocs) in mission data analysis activities.

  12. 3-DIMENSIONAL Geological Mapping and Modeling Activities at the Geological Survey of Norway

    NASA Astrophysics Data System (ADS)

    Jarna, A.; Bang-Kittilsen, A.; Haase, C.; Henderson, I. H. C.; Hgaas, F.; Iversen, S.; Seither, A.

    2015-10-01

    Geology and all geological structures are three-dimensional in space. Geology can be easily shown as four-dimensional when time is considered. Therefore GIS, databases, and 3D visualization software are common tools used by geoscientists to view, analyse, create models, interpret and communicate geological data. The NGU (Geological Survey of Norway) is the national institution for the study of bedrock, mineral resources, surficial deposits and groundwater and marine geology. The interest in 3D mapping and modelling has been reflected by the increase of number of groups and researches dealing with 3D in geology within NGU. This paper highlights 3D geological modelling techniques and the usage of these tools in bedrock, geophysics, urban and groundwater studies at NGU, same as visualisation of 3D online. The examples show use of a wide range of data, methods, software and an increased focus on interpretation and communication of geology in 3D. The goal is to gradually expand the geospatial data infrastructure to include 3D data at the same level as 2D.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

    Tellez-Arenas, Agns.; Serrano, Jean-Jacques; Tertre, Franois; 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 metamorphic character. For high resolution maps physical properties, bedding characteristics and weathering also need to be added. Furthermore, Geological data held by national geological surveys is generally described in national language of the country. The project has to deal with the multilingual issue, an important requirement of the INSPIRE directive. The project provides a list of harmonized vocabularies, a set of web services to deal with them, and a web site for helping the geoscientists while mapping the terms used into the national datasets into these vocabularies. The web services provided by each data provider, with the particular component that allows them to deliver the harmonised data model and to handle the multilingualism, are the first part of the architecture. The project also implements a web portal that provides several functionalities. Thanks to the common data model implemented by each web service delivering a part of the geological map, and using OGC SLD standards, the client offers the following option. A user can request for a sub-selection of the map, for instance searching on a particular attribute such as "age is quaternary", and display only the parts of the map according to the filter. Using the web services on the common vocabularies, the data displayed are translated. The project started September 2008 for two years, with 29 partners from 20 countries (20 partners are Geological Surveys). The budget is 3.25 M, with a European Commission contribution of 2.6 M. The paper will describe the technical solutions to implement OneGeology-Europe components: the profile of the common data model to exchange geological data, the web services to view and access geological data; and a geoportal to provide the user with a user-friendly way to discover, view and access geological data.

  15. 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 (2) gradual dissolution of primary minerals promoting significant CO2 reduction through the release of Fe(II). The reduction of CO2 is identified as a new trapping mechanism that could significantly enhance the long-term stability of GCS reservoirs. Identification of reservoir characteristics that promote CO2 redox transformations could be used as an additional factor in screening geologic reservoirs for GCS.

  16. Geologic Mapping of Mawrth Vallis and Nili Fossae, Mars

    NASA Astrophysics Data System (ADS)

    Bleamaster, L. F.; Chuang, F.

    2010-12-01

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

  17. Teaching about time by understanding Geologic Time Scales: The Geological Society of America Geologic Time Scale and its history

    NASA Astrophysics Data System (ADS)

    Geissman, J. W.; Walker, J. D.

    2012-12-01

    Geologic time scales, of one form or another, are used in most undergraduate geosciences courses, even including introductory physical geology or equivalent. However, satisfactory discussions of how geologic time scales originated, and how they have evolved to modern versions, are far too often conveniently or inconveniently left out of classroom discussions. Yet it is these kinds of discussions that have the potential of solidifying student appreciation of deep time and rates of geologic processes. We use the history and development of the Geological Society of America Geologic Time Scale, which reflects major developments in the fields of stratigraphy, geochronology, magnetic polarity stratigraphy, astrochronology, and chemostratigraphy, as a focus of how specific details of time scales can be used to teach about time. Advances in all of these fields have allowed many parts of the time scale to be calibrated to precisions approaching less than 0.05 %. Notable time intervals for which collaborative, multifaceted efforts have led to dramatic improvements in our understanding of the character and temporal resolution of key evolutionary events, in both marine and terrestrial environments, include the Triassic-Jurassic, Permo-Triassic, and Neoproterozoic-Phanerozoic boundaries (or transitions). Many of the details, but certainly not all, can be incorporated in discussions of how we know about geologic time in the classroom. For example, we presently understand that both the end-Permian ecological crisis and the biostratigraphic Permian-Triassic boundary, as calibrated by conodonts, lie within a ca. 700 ka long normal polarity chron. The reverse to normal polarity transition at the beginning of this chron is ca. 100 ka earlier than the ecological crisis and thus slightly older than the current estimate, based on high precision U-Pb zircon age determinations, of ca. 252.4 Ma for the Permian-Triassic boundary. This polarity transition occurred during the early part of the major negative del 13C isotope excursion that is estimated to have lasted ca. 500 ka beginning in the very latest Permian. Current geologic time scales are vastly improved over the first geologic time scale published by Holmes, nearly a hundred years ago in 1913, that used a total of eight numerical ages to establish the Phanerozoic time scale.

  18. 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 Survey of Japan, AIST is promoting OneGeology in Asia. The OneGeology portal was officially launched in 2008. Volcanic hazard maps are available for most major active volcanoes in Japan. A web-based GIS system combining various types of information with real time numerical simulations are very important for the next generation of volcanic hazard maps. Volcanic gravity flow simulations using the energy cone model were developed on GEO Grid system in AIST. An interactive user interface is available on the GEO Grid website. The pyroclastic flow simulation is open to all scientists and local government officials at http://geoapp.geogrid.org/gridsphere.

  19. 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.

  20. Global Bedrock Geology and River Chemistry

    NASA Astrophysics Data System (ADS)

    Peucker-Ehrenbrink, B.; Miller, M. W.

    2002-12-01

    The lack of modern quantitative estimates of the Earth`s surface geology, one of the key parameters influencing river (and ocean) chemistry, is striking. Most published estimates of area-age relationships of sedimentary bedrock, for instance, were published before the 1980s, were based on less detailed geologic maps often decades older, and used techniques such as cutting and weighting age correlative map units or point counting at fairly coarse resolution (Higgs, 1949; Gilluly, 1969; Blatt and Jones, 1975; Ronov, 1980). Even more recent estimates (e.g., Berry and Wilkinson, 1994) are based on data predating the 1980s (Cook and Bally, 1975; Ronov, 1980). In an attempt to gain quantitative understanding of the link between surface geology (bedrock chemistry and weatherability) and river (and ocean) chemistry we have initiated a global assessment of the Earth`s surface geology that is based on the latest digital geologic maps using modern geographic information system technology (Environmental Systems Research Institute`s ArcInfo software). To date we have completed analysis of three digital data sets: 1) the geologic map of the conterminous United States of America by King and Beikman (1974; 1:2,500,000; spatial resolution ~600 km2 per polygon), made available in digital format by the USGS, 2) the geologic map of Alaska by Beikman (1980; 1:2,5000,000; ~300 km2 per polygon), also available in digital form through the USGS, and 3) the geologic map of Canada that is based on a revised and updated version of the geologic map by Douglas (1969; 1:5,000,000; ~780 km2 per polygon), made available in digital form by the Geologic Survey of Canada. The data reveal, among others, the area-age relationship of sedimentary, volcanic, intrusive and metamorphic rocks at unprecedented temporal and spatial resolution. The data also provide quantitative estimates of the abundance of major rock types: sedimentary rocks make up 83% (US; 69.7% stratified, mostly marine and 13.5% continental), 73% (Alaska; 66.5% stratified, mostly marine and 6.3% continental), and ~52% (Canada; 43% mostly marine, 9% continental) of the bedrock. Volcanic rocks cover 9% (US), 11.6% (Alaska), and ~6% (Canada) of the surface, whereas intrusive rocks make up 5% (US), 6.6% (Alaska), and 24.5% (Canada) of the bedrock. Metamorphic rocks comprise 2.6% (US), 3.4% (Alaska), and 16.4% (Canada) of the bedrock. The maps also reveal the areal extent of minor lithologies such as ultramafic rocks that make up 0.15% (US), 0.20% (Alaska), and 0.08% (Canada) of the bedrock. In the next project phase we will combine information on the spatial distribution of bedrock in North America with digital maps of major river basins to investigate correlations between the abundance of rock types in drainage basins with river chemistry, specifically radiogenic isotope systems and macronutrients. Depending on the availability of additional digital geologic maps we will expand the assessment to other continents. Combining digital information on bedrock geology with digital maps of precipitation may allow us to use precipitation-weighted bedrock geology rather than simple area-lithology relationships. Extending this analysis to pre-Quaternary periods is beyond the current focus of our study. However, we feel such a historic perspective is necessary to fully understand and utilize reconstructions of ocean paleochemistry (e.g., the marine Os-, Hf-, Nd-, and Sr -isotope records) in models of global biogeochemical cycles (e.g., Bluth and Kump, 1991).

  1. 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 work of wind. I will conclude with an assessment of the prospects for endogenic activity in the form of tectonics and cryo-volcanism.

  2. Magnetic effects of hydrothermal alteration in porphyry copper and iron-oxide copper-gold systems: A review

    NASA Astrophysics Data System (ADS)

    Clark, David A.

    2014-06-01

    Magnetic anomaly patterns can be used as a tool for mapping lithology, metamorphic zones and hydrothermal alteration systems, as well as identifying structures that may control passage of magmas or hydrothermal fluids associated with mineralisation. Reliable geological interpretation of mineralised systems requires an understanding of the magmatic, metamorphic and hydrothermal processes that create, alter and destroy magnetic minerals in rocks. Predictive magnetic exploration models for porphyry copper and iron oxide copper-gold (IOCG) deposits can be derived from standard geological models by integrating magnetic petrological principles with petrophysical data, deposit descriptions, and modelling of observed magnetic signatures of these deposits. Even within a particular geological province, the magnetic signatures of similar deposits may differ substantially, due to differences in the local geological setting. Searching for look-alike signatures of a known deposit is likely to be unrewarding unless pertinent geological factors are taken into account. These factors include the tectonic setting and magma type, composition and disposition of host rocks, depth of emplacement and post-emplacement erosion level, depth of burial beneath younger cover, post-emplacement faulting and tilting, remanence effects contingent on ages of intrusion and alteration, and metamorphism. Because the effects of these factors on magnetic signatures are reasonably well understood, theoretical magnetic signatures appropriate for the local geological environment can qualitatively guide exploration and make semiquantitative predictions of anomaly amplitudes and patterns. The predictive models also allow detectability of deposit signatures to be assessed, for example when deposits are buried beneath a considerable thickness of nonmagnetic overburden, are covered by highly magnetic heterogeneous volcanic rocks, or there is a strong regional magnetic gradient. This paper reviews the effects of hydrothermal alteration on magnetic properties and magnetic signatures of porphyry copper and iron oxide copper-gold systems and presents examples of predictive magnetic exploration models, and their predicted signatures, in various geological circumstances.

  3. Geologic applications of Space Shuttle photography

    NASA Technical Reports Server (NTRS)

    Wood, Charles A.

    1989-01-01

    Space Shuttle astronauts have used handheld cameras to take about 30,000 photographs of the earth as seen from orbit. These pictures provide valuable, true-color depictions of many geologically significant areas. While the photographs have areal coverages and resolutions similar to the more familiar Landsat MSS and TM images, they differ from the latter in having a wide variety of solar illumination angles and look angles. Astronaut photographs can be used as very small scale aerial photographs for geologic mapping and planning logistical support for field work. Astronaut photography offers unique opportunities, because of the intelligence and training of the on-orbit observer, for documenting dynamic geologic activity such as volcanic eruptions, dust storms, etc. Astronauts have photographed more than 3 dozen volcanic eruption plumes, some of which were not reported otherwise. The stereographic capability of astronaut photography also permits three-dimensional interpretation of geologic landforms which is commonly useful in analysis of structural geology. Astronauts have also photographed about 20 known impact craters as part of project to discover presently unknown examples in Africa, South America, and Australia.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Geologic datasets for weights of evidence analysis in northeast Washington: 1. geologic raster data

    USGS Publications Warehouse

    Boleneus, David E.; Causey, J. Douglas

    2000-01-01

    This dataset contains the combination of geology data (geologic units, faults, folds, and dikes) from 6 1:100,000 scale digital coverages in eastern Washington (Chewelah, Colville, Omak, Oroville, Nespelem, Republic). The data was converted to an Arc grid in ArcView using the Spatial Analyst extension.

  9. 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/

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

    USGS Publications Warehouse

    Evan E. Thoms and Ralph A. Haugerud

    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.

  11. 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.

  12. The Geologic History of Seawater

    NASA Astrophysics Data System (ADS)

    Holland, H. D.

    2003-12-01

    Aristotle proposed that the saltness of the sea was due to the effect of sunlight on water. Robert Boyle took strong exception to this view and - in the manner of the Royal Society - laid out a program of research in the opening paragraph of his Observations and Experiments about the Saltness of the Sea (1674) (Figure 1): (20K)Figure 1. Title page of Robert Boyle's Tracts consisting of Observations about the Saltness of the Sea and other essays (1674). The Cause of the Saltness of the Sea appears by Aristotle's Writings to have busied the Curiosity of Naturalists before his time; since which, his Authority, perhaps much more than his Reasons, did for divers Ages make the Schools and the generality of Naturalists of his Opinion, till towards the end of the last Century, and the beginning of ours, some Learned Men took the boldness to question the common Opinion; since when the Controversie has been kept on foot, and, for ought I know, will be so, as long as tis argued on both sides but by Dialectical Arguments, which may be probable on both sides, but are not convincing on either. Wherefore I shall here briefly deliver some particulars about the Saltness of the Sea, obtained by my own trials, where I was able; and where I was not, by the best Relations I could procure, especially from Navigators.Boyle measured and compiled a considerable set of data for variations in the saltness of surface seawater. He also designed an improved piece of equipment for sampling seawater at depth, but the depths at which it was used were modest: 30 m with his own instrument, 80 m with another, similar sampler. However, the younger John Winthrop (1606-1676), an early member of the Royal Society, an important Governor of Connecticut, and a benefactor of Harvard College, was asked to collect seawater from the bottom of the Atlantic Ocean during his crossing from England to New England in the spring of 1663. The minutes of the Royal Society's meeting on July 20, 1663, give the 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 oceans, (ii) geochemical cycles, and (iii) the notion of a steady-state ocean

  13. Hypothesis tests for hydrologic alteration

    NASA Astrophysics Data System (ADS)

    Kroll, Charles N.; Croteau, Kelly E.; Vogel, Richard M.

    2015-11-01

    Hydrologic systems can be altered by anthropogenic and climatic influences. While there are a number of statistical frameworks for describing and evaluating the extent of hydrologic alteration, here we present a new framework for assessing whether statistically significant hydrologic alteration has occurred, or whether the shift in the hydrologic regime is consistent with the natural variability of the system. Four hypothesis tests based on shifts of flow duration curves (FDCs) are developed and tested using three different experimental designs based on different strategies for resampling of annual FDCs. The four hypothesis tests examined are the Kolmogorov-Smirnov (KS), Kuiper (K), confidence interval (CI), and ecosurplus and ecodeficit (Eco). Here 117 streamflow sites that have potentially undergone hydrologic alteration due to reservoir construction are examined. 20 years of pre-reservoir record is used to develop the critical value of the test statistic for type I errors of 5% and 10%, while 10 years of post-alteration record is used to examine the power of each test. The best experimental design, based on calculating the mean annual FDC from an exhaustive jackknife resampling regime, provided a larger number of unique values of each test statistic and properly reproduced type I errors. Of the four tests, the CI test consistently had the highest power, while the K test had the second highest power; KS and Eco always had the lowest power. The power of the CI test appeared related to the storage ratio of the reservoir, a rough measure of the hydrologic alteration of the system.

  14. 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.

  15. 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.

  16. 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.

    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.

  17. Acidic Alteration Environments on Mars and Implications for Habitability

    NASA Astrophysics Data System (ADS)

    Bishop, J. L.; Flahaut, J.; Weitz, C. M.; Gross, C.; Parente, M.; Horgan, B. H. N.

    2014-12-01

    Unique surface materials have been discovered recently at Valles Marineris (Roach et al., 2010; Weitz et al., 2014; Flahaut et al., 2014), Noctis Labyrinthus (Weitz et al., 2011), Mawrth Vallis (Bishop et al., 2013), and elsewhere that have CRISM features distinct from those of any known minerals. Typically these unusual sites are found in light-toned outcrops or interior layered deposits associated with phyllosilicates, sulfates or both. Frequently these units are called "doublet" materials because they exhibit a doublet absorption in CRISM spectra between 2.2 and 2.3 µm. We are investigating the spectral signatures of these martian materials compared to our library of minerals and alteration materials. We are also evaluating the stratigraphy of these unique alteration phases compared with neighboring phyllosilicate and sulfate units. A similar 2.2-2.3 µm doublet has been observed in spectra taken of acid altered clays produced in the laboratory (Madejova et al., 2009; Tosca et al., 2009). The band centers and relative intensities of these martian doublet features vary greatly suggesting that a process such as acid weathering could be acting on OH-bearing minerals to produce altered phases that differ depending on the type of substrate, water/rock ratio, solution chemistry, and duration of aqueous processes. Because these unique materials occur in many regions across a range of times on Mars, acidic alteration may have been a key process at local and regional scales throughout martian geologic history. Constraining the types of acidic alteration that have taken place on Mars will assist in defining the aqueous geochemistry at these sites and whether habitable conditions were possible. References: Bishop et al. (2013) PSS, 86, 130-149. Flahaut et al. (2014) EPSC, #211. Madejová et al. (2009) Vibrational Spectroscopy, 49, 211-218. Roach et al. (2010) Icarus, 206, 253-268. Tosca & Knoll (2009) 40th LPSC, #1538. Weitz et al. (2011) Geology, 39, 899-902. Weitz et al. (2014) Icarus, doi:10.1016/j.icarus.2014.04.009.

  18. 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. PMID:17272239

  19. 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.

  20. 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.

  1. Geology before Pluto: Pre-encounter considerations

    NASA Astrophysics Data System (ADS)

    Moore, Jeffrey M.; Howard, Alan D.; Schenk, Paul M.; McKinnon, William B.; Pappalardo, Robert T.; Ewing, Ryan C.; Bierhaus, Edward B.; Bray, Veronica J.; Spencer, John R.; Binzel, Richard P.; Buratti, Bonnie; Grundy, William M.; Olkin, Catherine B.; Reitsema, Harold J.; Reuter, Dennis C.; Stern, S. Alan; Weaver, Harold; Young, Leslie A.; Beyer, Ross A.

    2015-01-01

    The cameras of New Horizons will provide robust data sets that should be imminently amenable to geological analysis of the Pluto system's landscapes. In this paper, we begin with a brief discussion of the planned observations by the New Horizons cameras that will bear most directly on geological interpretability. Then we broadly review the major geological processes that could potentially operate on the surfaces of Pluto and its major moon Charon. We 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. We conclude with an assessment of the prospects for endogenic activity in the form of tectonics and cryovolcanism.

  2. 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.

  3. The influence of geology on blasthole deviation

    SciTech Connect

    Singh, S.P.

    1996-12-31

    Blasthole deviation is a frequent, well documented and undesirable occurrence in mining operations. It is caused by the drill string mechanics, operating variables and the interaction between the drill bit and the rock mass characteristics. It is composed of three distinct components: collaring or marking error, alignment error and trajectory deviation. This study has focused on the dependence of trajectory or natural deviation on the geological features of the rock mass being drilled. The methodology involved the study of visible half barrels at road cuts, open pits, quarries, underground drifting and breasting operations. The effects of the following geological features on drillhole deviation have been investigated and discussed in this paper (1) strength and hardness of rocks (2) alternate layers of hard and soft rocks (3) anisotropy in rock mass (4) thickness and inclination of layers and bedding planes and (5) joints or other geological boundaries.

  4. Chapter D in Geological Survey research 1964

    USGS Publications Warehouse

    U.S. Geological Survey

    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.

  5. 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.

  6. Geology and astrobiological implications of Argyre, Mars

    NASA Astrophysics Data System (ADS)

    Dohm, J. M.; El-Maarry, R.; Soare, R. J.; Williams, J.-P.; Conway, S. J.; Miyamoto, H.; Maruyama, S.

    2013-09-01

    Using Viking and post-Viking data, the detailed geological investigation of the Argyre impact basin and surroundings (30S to 65S, 290E to 340.0E; Fig.1) has: (1) resulted in a new geologic map of the region (Fig.2); (2) revealed the stratigraphical history of the region, including distinct sequence stratigraphy marking a lake that formed shortly after the Argyre impact event and the subsequent growth of Tharsis; (3) identified local lake-containing basins (Fig.3); (4) mapped the extent of Argyre-related tectonism and its influence on the surrounding regions, which includes a geophysical perspective; (5) been compared to a CRISM-based perspective which supports impact harvesting of mantle materials and aqueous activity in drainage systems including catchment basins; and (6) detailed ancient and geologically-recent surface modification (Fig.4).

  7. 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.

  8. 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.

  9. 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

    Geochemical analyses of major, trace, and rare earth elements (REE) in more than 200 samples of variably silicified and altered wall rocks, massive and banded sulfide, silica rock, and sulfide-rich and unmineralized barite were obtained from the Main, Aqqaluk, and Anarraaq deposits in the Red Dog Zn-Pb-Ag district of northern Alaska. Detailed lithogeochemical profiles for two drill cores at Aqqaluk display an antithetic relationship between SiO2/Al2O3 and TiO2/Zr which, together with textural information, suggest preferential silicification of carbonate-bearing sediments. Data for both drill cores also show generally high Tl, Sb, As, and Ge and uniformly positive Eu anomalies (Eu/Eu* > 1.0). Similar high Tl, Sb, As, Ge, and Eu/Eu* values are present in the footwall and shallow hanging wall of Zn-Pb-Ag sulfide intervals at Anarraaq but are not as widely dispersed. Net chemical changes for altered wall rocks in the district, on the basis of average Al-normalized data relative to unaltered black shales of the host Kuna Formation, include large enrichments (>50%) of Fe, Ba, Eu, V, S, Co, Zn, Pb, Tl, As, Sb, and Ge at both Red Dog and Anarraaq, Si at Red Dog, and Sr, U, and Se at Anarraaq. Large depletions (>50%) are evident for Ca at both Red Dog and Anarraaq, for Mg, P, and Y at Red Dog, and for Na at Anarraaq. At both Red Dog and Anarraaq, wall-rock alteration removed calcite and minor dolomite during hydrothermal decarbonation reactions and introduced Si, Eu, and Ge during silicification. Sulfidation reactions deposited Fe, S, Co, Zn, Pb, Tl, As, and Sb; barite mineralization introduced Ba, S, and Sr. Light REE and U were mobilized locally. This alteration and mineralization occurred during Mississippi an hydrothermal events that predated the Middle Jurassic-Cretaceous Brookian orogeny. Early hydrothermal silicification at Red Dog took place prior to or during massive sulfide mineralization, on the basis of the dominantly planar nature of Zn-Pb veins, which suggests 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.

  10. 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.

  11. 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.

  12. Geological Survey Research 1966, Chapter A

    USGS Publications Warehouse

    U.S. Geological Survey

    1966-01-01

    'Geological Survey Research 1966' is the seventh annual review of the econamic and scientific work of the U.S. Geological Survey. As in previous years the purpose of the volume is to make available promptly to the public the highlights of Survey investigations. This year the volume consists of 4 chapters (A through D) of Professional Paper 550. Chapter A contains a summary of significant results, and the remaining chapters are made up of collections of short technical papers. Many of the results summarized in chapter A are discussed in greater detail in the short papers or in reports listed in 'Publications in Fiscal Year 1966,' beginning on page A265. The tables of contents for chapters B through D are listed on pages A259-A264. Numerous Federal, State, county, and municipal agencies listed on pages A211-A215 cooperated financially with the Geological Survey during fiscal 1966 and have contributed significantly to the results reported here. They are identified where appropriate in the short technical papers that have appeared in Geological Survey Research and in papers published cooperatively, but generally are not identified in the brief statements in chapter A. Many individuals on the staff of the Geological Survey have contributed to 'Geological Survey Research 1966.' Reference is made to only a few. Frank W. Trainer, Water Resources Division, was responsible for organizing and assembling chapter A and for critical review of papers in chapters B-D, assisted by Louis Pavlides, Geologic Division. Marston S. Chase, Publications Division, was in charge of production aspects of the series, assisted by Jesse R. Upperco in technical editing, and William H. Elliott and James R. Hamilton in planning and preparing illustrations. The volume for next year, 'Geological Survey Research 1967,' will be published as chapters af Professional Paper 5715. Previous volumes are listed below, with their series designations. Gealagical Survey Research 1960-Prof. Paper 400 Gealagical Survey Research 1961-Prof. Paper 424 Gealagical Survey Research 1962-Prof. Paper 450 Gealagical Survey Research 1963-Prof. Paper 475 Gealagical Survey Research 1964-Prof. Paper 501 Gealagical Survey Research 1965-Prof. Paper 525

  13. 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 Kentuckyincluding collections from oil and gas exploration operations, coal and other mining companies, highway construction projects, environmental studies, and federal facilities such as Fort Knoxand 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.

  14. 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.

  15. 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.

  16. 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

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

    NASA Astrophysics Data System (ADS)

    Duffy, Tim; Tellez-Arenas, Agnes

    2014-05-01

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

  18. Diverse Alteration Minerals Around Martian Impact Craters Revealed by MRO-CRISM: Indicators of Hydrothermal Activity or Subsurface Aqueous Alteration?

    NASA Astrophysics Data System (ADS)

    Ehlmann, B. L.; Mustard, J. F.; Fraeman, A. A.; Barnouin-Jha, O. S.; Wray, J. J.; Murchie, S. L.; CRISM Science Team

    2008-12-01

    Hydrated silicates indicating aqueous alteration of mafic rocks have been identified in central peak, wall, and ejecta rocks of many impact craters. CRISM has revealed 1000s of exposures in the Southern Highlands, often associated with craters, with Fe/Mg smectite-bearing rocks, and a small percentage with more diverse alteration minerals. Chlorite is not uncommon and kaolinite, illite or muscovite, hydrated silica, and zeolites are sometimes present, albeit infrequently. Understanding the geologic setting and formation processes of aqueous mineral deposits is important for determining whether alteration pre-dated the impact crater or whether mineralogic products are more recent and represent evidence for post-impact alteration, perhaps in hydrothermal systems. Using combined CRISM-CTX-HiRISE observations, we assess this in detail for craters of unusually diverse alteration mineralogy in the region west of the Isidis basin. Three types of information are considered: (1) Stratigraphy and geomorphic setting of crater hydrated silicates, (2) constraints on the temperature, pressure, and geochemical conditions required for the formation and stability of each alteration mineral, and (3) models of the temperatures experienced in impact processes. Two main classes of craters with diverse alteration minerals exist between the Nili Fossae and Antoniadi basin: (1) craters dominated by chlorite with illite and smectite also present and (2) craters with Fe/Mg smectite, chlorite, and the zeolite analcime in the central peaks. In (2), materials in sands ringing the peak are hydrated and Si-OH bearing, which may indicate either hydrated silica (e.g. chalcedony) or an aqueously altered basaltic glass. These sands also correspond to the unique units identified by TES with elevated quartz and alkali feldspars and interpreted to be quartzofeldspathic (QF)/granitoid material. Fe/Mg-rich smectites or chlorites with accessory zeolite, silica, quartz, and K-feldspar result from hydrothermal alteration in terrestrial craters (e.g. Allen et al., 1982; Naumov, 2005) and suggest a possible reinterpretation of the QF material in (2) as hydrothermal in origin rather than igneous. Experimental data show analcime-smectite assemblages result from aqueously altered glasses and basalt powders at temperatures T < 200 C (Robert and Goffe, 1993). Illite-chlorite assemblages are stable at T~200- 260 C. Variation in the temperature, water-rock ratio, and fluid chemistry of a hydrothermal system may result in these distinctive mineral assemblages observed in Nili Fossae craters. An alternative hypothesis is that alteration materials associated with craters reflect changes in underlying crustal materials west of Isidis and that aqueous alteration pre-dated formation of the impact structures in which these minerals are mapped. Smectite transforms to illite upon burial at T>50-80 C, and illite and chlorite altered at depth may have been excavated by impact. Both hypotheses--subsurface pre-impact alteration and post-impact hydrothermal alteration--will be examined with new MRO data.

  19. 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 for characterization of geologic units at a scale that is not possible with Magellan altimetry or products derived from the altimetry. Relative ages of the geologic units are determined using the well-known principles of superposition and intersection. Here, the perception of relief is invaluable because superposition relations among the geological units are more readily and clearly established. The recognition of folds, faults, and fault systems, regardless of their orientations, is facilitated with stereopsis so that sequences of deformation of the geologic units can be determined and structural analyses vastly improved. Shapes of landforms are readily perceived so that they can be properly interpreted. The end result of the mapping, analyses, and interpretations is a geologic history of Venus that includes the sequences of formation and deformation of various geologic units. Measurements of relief at the finest scale possible are necessary for numerous topical studies. Standard altimetry will provide the necessary information on the relief of most large landforms, but it tends to underestimate the relief of small landforms and distorts their shapes. Although special processing of the altimeter echoes improves the estimates of the relief and shapes of some landforms, there are uncertainties in the interpretations of the echoes. Examples of topical studies requiring measurements of relief are given.

  20. 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.

  1. 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.

  2. Remote sensing information identification technology for tectonic geological interpretation in Yinchuan area

    NASA Astrophysics Data System (ADS)

    Guo, Bang-jie; Zhang, Jie-lin; Wu, Ding; Zhang, Chuan; Liu, Yong-ming; Cui, Yuan-yuan

    2014-11-01

    Remote sensing technology takes the important role in the geological features identification of structure, strata, alterations and plutons. This paper uses satellite high spatial resolution remote sensing image and information identification technology to analyze tectonic geological features in Yinchuan basin, and better results are achieved. Based on image enhancement and geological interpretation, the structural characteristics including Helan mount large fold belt, Weining-beishan sawtooth structure and en echelon faults of Yinchuan area are analyzed and combined with seismic information, the causes of Yinchuan graben and its surrounding structures are discussed. Results shows all those structural characteristics and phenomena are caused by Yanshan movement and Himalayan movement, and Yinchuan graben is formed in the pulling tension environment caused by Himalayan movement on the basis of Helan-Hengshanbu fault belt which created by Yanshan movement. The tectonic evolution period times are determinated by this results and it is important for oil and gas exploration. Remote sensing information identification technology provides the new perspective and approach for geological research.

  3. 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 extremely useful accompaniment to compilation of field mapping efforts. It can also complement published geologic maps by vastly improving their comprehensibility when field photos, and specific notes can be viewed interactively with them. Other useful applications include GPS tracking/documentation of field traverses; invoking multiple geologic layers; 3-D visualizations of terrain and structure; and online collaboration with colleagues via blogs or wikis. Additional steps towards collaborative geologic mapping on the web may also enhance efficient and open sharing of data and ideas. Geologists are well aware that paper geologic maps can convey tremendous amounts of information. Digital geologic maps linked via a virtual globe with field data, diverse imagery, historical photographs, explanatory diagrams, and 3-D models convey a much greater amount of information and can provide a much richer context for comprehension and interpretation. They can also serve as an efficient, entertaining, and potentially compelling mechanism for fostering inspiration in the minds of budding (and aging) geologists.

  4. 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.

  5. 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.

  6. 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)

  7. 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.

  8. Geologic issues in environmental impact analyses

    SciTech Connect

    Almy, R.B.

    1985-01-01

    Environmental impact reports/statements are required by California and/or Federal law for most major development projects in California. Recent interest in, and development of, the petroleum resources in western Santa Barbara County have required a number of exhaustive impact reports. Their general format includes project description, environmental setting, assessment of impacts, and suggested mitigation measures to reduce impacts. Although most environmental issue areas, including geologic resources, fit well into this format, geologic hazards do not. Since the proposed facilities include offshore platforms, onshore processing facilities, and major interconnecting pipelines and since the potential impacts under upset conditions are substantial, these projects provide particularly good examples of the treatment of geologic hazards as well as resources affected. Geologic resources such as economic deposits and paleontological occurrences are treated as other sensitive resources, and mitigation measures developed to reduce impacts to them. Geohazards such as faults, landslides, and scour-prone rivers are related to potential failure scenarios. Level of impacts to various resource areas are assessed under likely failure scenarios. In this way, regulatory agencies charged with developing specific conditions to reduce impacts can focus both on reducing project impacts, as well as engineering or sitting alternatives which may significantly reduce the impacts of low risk but high consequence events.

  9. Applications of geohydrologic concepts in geology

    USGS Publications Warehouse

    Maxey, G.B.; Hackett, J.E.

    1963-01-01

    Subsurface water, an active agent in many geologic proceses, must be considered in interpreting geologic phenomena. Principles of the occurrence, distribution, and movement of subsurface waters are well established and readily applicable. In many interpretations in geologic literature, geohydrologic principles have been employed realistically, but in many others these principles have been either ignored or violated. Explanations of genesis of underclays and associated deposits afford some examples wherein principles of movement and activity of vadose and ground water have been ignored and others in which they have been used advantageously. Postulates stating that waters percolate downward from swamp areas do not allow for the usual movement of subsurface water in such environments. The idea that sediments were leached by vadose water after uplift satisfies the geohydrologic requirements. Weathering and solution form porous and permeable zones subjacent to unconformities in dense rocks such as carbonates and granites; this illustrates the geohydrologic and economic significance of unconformities. Examples are Mohawkian carbonate aquifers of northern Illinois and oil-bearing limestones of Mississippian age of eastern Montana. The flushing effects of meteoric water and other hydrodynamic factors active during erosion periods are important elements in the genesis and concentration of brines. Explanation of the origin and occurrence of brines must include consideration of the geohydrologic environments throughout their geologic history. ?? 1963.

  10. 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

  11. 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.

  12. 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.

  13. 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…

  14. Nuclear-waste disposal in geologic repositories

    SciTech Connect

    Isherwood, D.

    1982-08-02

    Deep geologic repositories are being widely studied as the most favored method of disposal of nuclear waste. Scientists search for repository sites in salt, basalt, tuff and granite that are geologically and hydrologically suitable. The systematic evaluation of the safety and reliability of deep geologic disposal centers around the concept of interacting multiple barriers. The simplest element to describe of the geologic barrier is the physical isolation of the waste in a remote region at some depth within the rock unit. Of greater complexity is the hydrologic barrier which is determined by the waste dilution factors and groundwater flow rates. The least understood is the geochemical barrier, identified as a series of waste/water/rock interactions involving sorption, membrane filtration, precipitation and complexing. In addition to the natural barriers are the engineered barriers, which include the waste form and waste package. The relative effectiveness of these barriers to provide long-term isolation of nuclear waste from the human environment is being assessed through the use of analytical and numerical models. The data used in the models is generally adequate for parameter sensitivity studies which bound the uncertainties in the release and transport predictions; however, much of the data comes from laboratory testing, and the problem of correlating laboratory and field measurements has not been resolved. Although safety assessments based on generic sites have been useful in the past for developing site selection criteria, site-specific studies are needed to judge the suitability of a particular host rock and its environment.

  15. 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

  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. 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.

  19. 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.

  20. A Field Course in Urban Geology

    ERIC Educational Resources Information Center

    Burger, H. Robert

    1973-01-01

    Describes a course attempting to educate people in environmental and urban matters. It is divided into two sections: One section for geology and the other science majors; the other for non-science majors who had not taken a college-level laboratory science. (DF)

  1. Geologic controls on radon occurrence in Georgia

    SciTech Connect

    Gregg, L.T. ); Coker, G. )

    1990-01-01

    Conventional wisdom holds that high radon concentrations occur mostly in areas of thin and/or sandy soils underlain by granitic bedrock, that other soil conditions and bedrock lithologies are less prone to high radon concentrations, and that high radon levels in groundwater represent an isolated phenomenon. Through a combination of geologic models and field measurements, each of the four geologic provinces of Georgia can be characterized for radon concentration. The results to date indicate that no area or geologic province should be exempted per se and that a careful study of site/area geology along with field measurement will yield dividends in understanding the occurrence of radon in soil and groundwater. The combinations of bedrock lithology and soil characteristics most likely to exhibit higher radon concentrations in Georgia, and throughout the southeast, are (a) granites, granodiorites, granite gneisses, pegmatites, mylonites, carbonaceous shales, phosphates, and monazite/heavy mineral placers, coupled with (b) high to medium permeability soils such as gravels, sands, and uniformly-graded silts and sandy silts. Saprolite and surficial soil may act as either a conduit or an impediment to radon migration, as may hydrogeologic characteristics and rock structures such as faults and joints/fractures.

  2. Status of Geological Education in Iranian Universities

    ERIC Educational Resources Information Center

    Shomali, Bahman Saghatchian; Hungerford, Harold R.

    1974-01-01

    A statistical survey revealed that education in three Iranian universities is primarily based on memorizing and recalling theoretical knowledge rather than on applying knowledge and skills in solving geological problems, and also that the curricula ignore the fact that the study of the earth is an interdisciplinary science. (MLH)

  3. US GEOLOGICAL SURVEY WELL WATERLEVEL DATA, NC

    EPA Science Inventory

    USGS well waterlevel data for NC wells, as provided by North Carolina Department of Environment and Natural Resources (NC-DENR). The zipped file contains 2 FoxPro databases:
    usgs.dbf - This database contains the well construction information for the US Geological Survey's moni...

  4. 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.

  5. The Emerging Medical and Geological Association

    PubMed Central

    Finkelman, Robert B; Centeno, Jose A; Selinus, Olle

    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. PMID:16555612

  6. 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.

  7. 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.

  8. Bedrock geology and chemistry of rivers basins

    NASA Astrophysics Data System (ADS)

    Peucker-Ehrenbrink, B.; Miller, M. W.

    2003-04-01

    The lack of modern quantitative estimates of the Earths surface geology, one of the key parameters influencing river and ocean chemistry, is striking. While some attempts have been made to quantify the lithologic composition of bedrock in individual river basins (e.g., Reeder et al., 1972; Amiotte-Suchet et al., 2002), the geologic age distribution of bedrock in river basins has not been investigated. We have therefore initiated a project aimed at generating a worldwide dataset on the bedrock lithology and age distribution of river basins, using the latest digital geologic maps and modern geographic information system technology. To date we have completed analysis of the digital geologic maps North America. These data have been used in conjunction with digital river basin polygons (Revenga et al., 1998, World Resources Institute) to compute the lithologic composition and geologic age structure of major river basins in North America. The lithologic composition of 14 large river basins range from predominantly igneous rocks dominated (Frazer, Columbia), to those dominated by sedimentary rocks (Brazos, Susquehanna, Mississippi), to basins with an equal mix of igneous, metamorphic and sedimentary bedrock (Thelon). Subdividing sedimentary rocks into marine and continental rocks reveals that continental sediments account for no more than 25% of sedimentary rocks in these river basins (e.g., Nelson, Colorado, Mississippi). A further subdivision of igneous rocks into intrusive and volcanic rocks reveals the entire range of igneous composition, from basins dominated by intrusive rocks (Hudson, Mackenzie, Nelson) to those dominated by volcanic rocks (Susquehanna, Colorado, Frazer, Columbia). We are currently analyzing the age distribution of major lithologic units in each river basin. In cases where detailed hydrochemical data is available for major tributaries we will expand the analysis to sub-basins (e.g., Frazer, Mississippi). Basins smaller than about 40,000 km^2 will require analysis of higher-resolution digital geologic bedrock maps. In the next project phase we will combine bedrock data for major river basins with hydrochemical data to investigate the influence bedrock exerts on river chemistry, specifically radiogenic isotopes and macronutrients. Combining digital information on bedrock geology with digital maps of precipitation will allow us to use precipitation-weighted bedrock area rather than simple area-lithology relationships. Extending this analysis to pre-Quaternary periods is beyond the current focus of the project, but will be necessary to fully utilize reconstructions of ocean paleochemistry in models of global biogeochemical cycles (e.g., Bluth and Kump, 1991).

  9. 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 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.

  10. 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 "integrated", meaning integration between natural components, including geological, biological and anthropogenic elements, climate, history, architecture, literature etc. Secondly, Goethe's scientific intuitions (in this case the geological ones) were compared with the evolution of scientific knowledge up to most recent times, which at times confirm what Goethe had already realised. This project is based on the description of the stages of his journey, in the light of modern results of investigations carried out in geology, geomorphology, mineralogy etc. This research is grateful for the contributions of many geologists from various universities and Italian research institutions from the Alps to Sicily. Goethe's Italian journey as revisited in this paper aims to stimulate the interest of the reader in the "geological" component of the environment in which we live by means of an "integrated" approach.

  11. The Geologic History of Mars: An Astrobiology Perspective

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K.; Westall, Frances; McKay, David S.; Thomas-Keprta, Kathie; Socki, Richard A.

    2000-01-01

    Fourteen SNC meteorites contain information which must be incorporated with recent spaceflight data for developing Mars' geologic history. SNCs have crystallization ages of 4500 to 160 m.y. Tle oldest meteorite ALH84001 contains information on the Noachian period of Mars' history. There are no meteorites from the Hesperian period and the remaining 13 meteorites fall into two age groups within the Amazonian: The nakhlites around 1300 m.y. and the shergottites between 800-160 m.y. Oxygen isotopic analysis of Martian samples shows two distinct O2 reservoirs throughout Martian history indicating late additions of volatiles and a lack of plate tectonics prior to 3.9 Gy. Evidence for percolation of aqueous brines through impact-produced fractures in the rocky surface is contained in the 3.9 Gy-old ALH84001 carbonate deposits. These carbonates precipitated at approx. 100 C. At this time life had already evolved on Earth. Early Mars could have hosted life similar to the bacteria that inhabited early Earth. Potential microorganisms could have been transported into fractures by carbonate-bearing waters and their remains could have become incorporated into the precipitated carbonate. Since Mars had a weak magnetic field at this time, it can be hypothesized that some of the Martian microorganisms may have been similar to terrestrial magnetotactic bacteria. Over geologic time episodic cratering, and tectonic events have occurred on Mars along with the periodic release of subsurface waters which may have produced clays within SNC meteorites. The geochemical data contained within SNC meteorites complements previous observational data and the recent Mars Global Surveyor data to provide a geological and environmental history which spans almost the entire lifespan on Mars. One of the outstanding features of this model is the possible creation of an early (about 4 Gy) volatile reservoir distinct from the outgassed Mars volatiles, and the persistence of this reservoir throughout most, if not all of subsequent Mars' history. Within the framework of this history a potential scenario for a possible record of living organisms is provided by suggestive structures and organic signatures trapped within secondary mineral deposits and alteration features of some SNC meteorites. Tracing the differences in oxygen isotopic compositions within Martian components allows us to gain insight in the history of Mars.

  12. Lithologic discrimination and alteration mapping from AVIRIS Data, Socorro, New Mexico

    NASA Technical Reports Server (NTRS)

    Beratan, K. K.; Delillo, N.; Jacobson, A.; Blom, R.; Chapin, C. E.

    1993-01-01

    Geologic maps are, by their very nature, interpretive documents. In contrasts, images prepared from AVIRIS data can be used as uninterpreted, and thus unbiased, geologic maps. We are having significant success applying AVIRIS data in this non-quantitative manner to geologic problems. Much of our success has come from the power of the Linked Windows Interactive Data System. LinkWinds is a visual data analysis and exploration system under development at JPL which is designed to rapidly and interactively investigate large multivariate data sets. In this paper, we present information on the analysis technique, and preliminary results from research on potassium metasomatism, a distinctive and structurally significant type of alteration associated with crustal extension.

  13. Analysis of the U.S. geological survey streamgaging network

    USGS Publications Warehouse

    Scott, A.G.

    1987-01-01

    This paper summarizes the results from the first 3 years of a 5-year cost-effectiveness study of the U.S. Geological Survey streamgaging network. The objective of the study is to define and document the most cost-effective means of furnishing streamflow information. In the first step of this study, data uses were identified for 3,493 continuous-record stations currently being operated in 32 States. In the second step, evaluation of alternative methods of providing streamflow information, flow-routing models, and regression models were developed for estimating daily flows at 251 stations of the 3,493 stations analyzed. In the third step of the analysis, relationships were developed between the accuracy of the streamflow records and the operating budget. The weighted standard error for all stations, with current operating procedures, was 19.9 percent. By altering field activities, as determined by the analyses, this could be reduced to 17.8 percent. The existing streamgaging networks in four Districts were further analyzed to determine the impacts that satellite telemetry would have on the cost effectiveness. Satellite telemetry was not found to be cost effective on the basis of hydrologic data collection alone, given present cost of equipment and operation.This paper summarizes the results from the first 3 years of a 5-year cost-effectiveness study of the U. S. Geological Survey streamgaging network. The objective of the study is to define and document the most cost-effective means of furnishing streamflow information. In the first step of this study, data uses were identified for 3,493 continuous-record stations currently being operated in 32 States. In the second step, evaluation of alternative methods of providing streamflow information, flow-routing models, and regression models were developed for estimating daily flows at 251 stations of the 3, 493 stations analyzed. In the third step of the analysis, relationships were developed between the accuracy of the streamflow records and the operating budget. The weighted standard error for all stations, with current operating procedures, was 19. 9 percent. By altering field activities, as determined by the analyses, this could be reduced to 17. 8 percent. Additional study results are discussed.

  14. VOSGES, a long and rich geologic history

    NASA Astrophysics Data System (ADS)

    Dominique, Carteaux; Cyrille, Delangle; Sophie, Demangel

    2015-04-01

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

  15. Geologic emissions of methane to the atmosphere.

    PubMed

    Etiope, Giuseppe; Klusman, Ronald W

    2002-12-01

    The atmospheric methane budget is commonly defined assuming that major sources derive from the biosphere (wetlands, rice paddies, animals, termites) and that fossil, radiocarbon-free CH4 emission is due to and mediated by anthropogenic activity (natural gas production and distribution, and coal mining). However, the amount of radiocarbon-free CH4 in the atmosphere, estimated at approximately 20% of atmospheric CH4, is higher than the estimates from statistical data of CH4 emission from fossil fuel related anthropogenic sources. This work documents that significant amounts of "old" methane, produced within the Earth crust, can be released naturally into the atmosphere through gas permeable faults and fractured rocks. Major geologic emissions of methane are related to hydrocarbon production in sedimentary basins (biogenic and thermogenic methane) and, subordinately, to inorganic reactions (Fischer-Tropsch type) in geothermal systems. Geologic CH4 emissions include diffuse fluxes over wide areas, or microseepage, on the order of 10(0)-10(2) mg m(-2) day(-1), and localised flows and gas vents, on the order of 10(2) t y(-1), both on land and on the seafloor. Mud volcanoes producing flows of up to 10(3) t y(-1) represent the largest visible expression of geologic methane emission. Several studies have indicated that methanotrophic consumption in soil may be insufficient to consume all leaking geologic CH4 and positive fluxes into the atmosphere can take place in dry or seasonally cold environments. Unsaturated soils have generally been considered a major sink for atmospheric methane, and never a continuous, intermittent, or localised source to the atmosphere. Although geologic CH4 sources need to be quantified more accurately, a preliminary global estimate indicates that there are likely more than enough sources to provide the amount of methane required to account for the suspected missing source of fossil CH4. PMID:12430657

  16. Mars geologic mapping program: Review and highlights

    NASA Technical Reports Server (NTRS)

    Scott, David H.

    1991-01-01

    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 from solar heating and sublimation by a weathering rind or lag deposit on the surface.

  17. Geological Investigations of Mars: The Human Factor

    NASA Astrophysics Data System (ADS)

    Neal, Clive R.

    2001-01-01

    Humans make better geologists than robots, and putting astronauts on the surface of Mars will greatly enhance scientific exploration and increase the chances for key scientific discoveries. Humans can recognize interesting samples and, importantly, place those samples in the overall geological context of the particular landing site. These attributes were amply demonstrated during the Apollo program, as for example when Jack Schmitt accidentally slipped and discovered the "orange soil" (glass beads) at the Apollo 17 site. These samples remain some of the most important collected during the Apollo program and are still being analyzed by scientists worldwide. Because the Apollo missions were each of limited duration, no instruments were carried along for actual analysis of rock samples prior to returning them to Earth. However, human expeditions to Mars will likely involve extended stays (months). Assuming a limited capacity for returning geological samples, it will be highly advantageous to carry some rudimentary kinds of analytical equipment to the Martian surface in order to ensure that the most significant geological samples are collected and returned to Earth. This paper discusses some of the most useful and practical types of analytical equipment that might be taken along in order to characterize geological samples on the surface of Mars. Some useful tools actually can be carried by astronauts into "the field" as opposed to remaining on the spacecraft lander. These portable instruments are mainly the simplest yet most important instruments. There is no substitute for a human eye coupled with a well-trained mind, and what the eye can see will be greatly enhanced by having a geological hammer (to expose fresh rock surfaces) and some kind of helmet compatible magnifier for first-order rock and mineral characterization.

  18. Charles Lyell and scientific thinking in geology

    NASA Astrophysics Data System (ADS)

    Virgili, Carmina

    2007-07-01

    Charles Lyell (1797-1875) was born at Kinnordy, Scotland. His father, an amateur botanist, and his grandfather, a navigator, gave him very soon a taste for the observation of the Nature. He went to the Oxford University to study classical literature, but he also followed the geological course of William Buckland. After having been employed as jurist for some years, in 1827 he decided on a career of geologist and held the chair of geology of the King's College of London, from 1831 on. He was a contemporary of Cuvier, Darwin, von Humboldt, Hutton, Lavoisier, and was elected 'membre correspondant' of the 'Académie des sciences, France', in January 1862. Charles Lyell is one of the eminent geologists who initiated the scientific thinking in geology, in which his famous volumes of the Principles of Geology were taken as the authority. These reference volumes are based on multiple observations and field works collected during numerous fieldtrips in western Europe (principally Spain, France, and Italy) and North America. To his name are attached, among others: ( i) the concept of uniformitarism (or actualism), which was opposed to the famous catastrophism, in vogue at that time, and which may be summarized by the expression "The present is the key to the past"; ( ii) the division of the Tertiary in three series denominated Eocene, Miocene, and Pliocene, due to the study of the age of strata by fossil faunas; ( iii) the theory according to which the orogenesis of a mountain chain, as the Pyrenees, results from different pulsations on very long time scales and was not induced by a unique pulsation during a short and intense period. The uniformity of the laws of Nature is undeniably a principle Charles Lyell was the first to state clearly and to apply to the study of the whole Earth's crust, which opened a new era in geology.

  19. Economic geology of the Bingham mining district, Utah, with a section on areal geology, and an introduction on general geology

    USGS Publications Warehouse

    Boutwell, J.M.; Keith, Arthur; Emmons, S.F.

    1905-01-01

    The field work of which this report represents the final results was first undertaken in the summer of the year 1900. This district had long been selected by the writer as worthy of special economic investigation, as well on account of the importance of its products as because of its geological structure and the peculiar relations of its ore deposits. It was not, however, until the summer mentioned above that the means at the disposal of the Survey, both pecuniary and scientific, justified its undertaking. As originally planned, the areal or surface geology was to have been worked out by Mr. Keith, who had already spent many years in unraveling the complicated geological structure of the Appalachian province, while Mr. Boutwell, who had more recently become attached to the Survey, was to have charge of the underground geology, or a study of the ore deposits, under the immediate supervision of the writer. When the time came for actually taking the field, it was found that the pressure of other work would not permit Mr. Keith to carry out fully the part allotted to him, and in consequence a part of his field work has fallen to Mr. Boutwell. Field work was commenced by the writer and Mr. Boutwell early in July, 1900. Mr. Keith joined the party on August 10, but was obliged to leave for other duties early in September. Mr. Boutwell carried on his field work continuously from July until December, taking up underground work after the snowfall had rendered work on the surface geology impracticable. The geological structure had proved to be unexpectedly intricate and complicated, so that, on the opening of the field season of 1901, it was found necessary to make further study in the light of results already worked out, and Mr. Boutwell spent some weeks in the district in the early summer of 1901. His field work that year, partly in California and partly in Arizona, as assistant to Mr. Waldemar Lindgren, lasted through the summer and winter and well into the spring of 1902, so that but little time , was left before he was obliged to take the field again in his study of the Park City district of Utah. Mr. Keith had been too closely occupied with his Appalachian work to complete his part,' and thus the publication of this report has been unusually delayed. While the delay is a cause for regret, this regret is much tempered by the consideration that had the report been published earlier many facts brought to light during the vigorous development of the region in late years, which have an important bearing upon the structure and genesis of the ore deposits, could not have been used in its preparation.

  20. The use of high resolution ground and airborne magnetic surveys to evaluate the geometry of hydrothermal alteration zones over volcanic provinces (Invited)

    NASA Astrophysics Data System (ADS)

    Bouligand, C.; Glen, J. M.

    2013-12-01

    Geophysical methods can provide critical constraints on the distribution and volume of hydrothermal alteration, important parameters in understanding the evolution of geothermal systems. Because hydrothermal alteration modifies the magnetic properties of the volcanic substratum, magnetic surveys can be used to provide constraints on the distribution of hydrothermal alteration at depth. Using Yellowstone caldera as an example, we show that both ground and airborne magnetic surveys can be used to map and assess the volume of hydrothermal alteration. Ground magnetic surveys over unaltered volcanic terranes display high-amplitude, short-wavelength anomalies, in contrast to smooth, subdued magnetic anomalies over volcanic substrata demagnetized by hydrothermal alteration. We use this contrast to map areas of hydrothermal alteration in detail. Inverse methods applied to high-resolution airborne and ground magnetic data can be used to create three-dimensional models of the distribution of magnetization and thus illuminate the geometry of hydrothermal alteration. Because of the non-uniqueness of potential fields, the construction of inverse models requires simplifying assumptions on the distribution of magnetization, knowledge of induced and remanent magnetization of fresh and altered geological units, and detailed geological and geophysical data. Within the three hydrothermal sites that we investigated in Yellowstone National Park, subdued short-wavelength signal indicates pervasive demagnetization (alteration) of the shallow substratum that extends over larger areas than initially mapped by geology. These data also reveal that the largest degree of demagnetization (alteration) and maximum thicknesses of demagnetized (altered) substratum, reaching a few hundred meters, are associated with hydrothermal vents and with superficial hydrothermal alteration. Our three dimensional models of magnetization provide estimates of the volume of buried hydrothermal alteration ranging from 10 to 20 km3 buried within each of our 10 x 10 km2 study areas.

  1. Effects Of Hydrothermal Alteration On Magnetic Properties And Magnetic Signatures - Implications For Predictive Magnetic Exploration Models

    NASA Astrophysics Data System (ADS)

    Clark, D.

    2012-12-01

    Magnetics is the most widely used geophysical method in hard rock exploration and magnetic surveys are an integral part of exploration programs for many types of mineral deposit, including porphyry Cu, intrusive-related gold, volcanic-hosted epithermal Au, IOCG, VMS, and Ni sulfide deposits. However, the magnetic signatures of ore deposits and their associated mineralized systems are extremely variable and exploration that is based simply on searching for signatures that resemble those of known deposits and systems is rarely successful. Predictive magnetic exploration models are based upon well-established geological models, combined with magnetic property measurements and geological information from well-studied deposits, and guided by magnetic petrological understanding of the processes that create, destroy and modify magnetic minerals in rocks. These models are designed to guide exploration by predicting magnetic signatures that are appropriate to specific geological settings, taking into account factors such as tectonic province; protolith composition; post-formation tilting/faulting/ burial/ exhumation and partial erosion; and metamorphism. Patterns of zoned hydrothermal alteration are important indicators of potentially mineralized systems and, if properly interpreted, can provided vectors to ore. Magnetic signatures associated with these patterns at a range of scales can provide valuable information on prospectivity and can guide drilling, provided they are correctly interpreted in geological terms. This presentation reviews effects of the important types of hydrothermal alteration on magnetic properties within mineralized systems, with particular reference to porphyry copper and IOCG deposits. For example, an unmodified gold-rich porphyry copper system, emplaced into mafic-intermediate volcanic host rocks (such as Bajo de la Alumbrera, Argentina) exhibits an inner potassic zone that is strongly mineralized and magnetite-rich, which is surrounded by an outer potassic zone that contains less abundant, but still significant, magnetite. The inner potassic zone represents relatively intense development of qtz-mt-Kfsp veins, whereas the outer potassic zone corresponds to bio-Kfsp-qtz-mt alteration. A shell of magnetite-destructive phyllic alteration with very low susceptibility envelops the potassic zones. The phyllic zone is surrounded by a zone of intense propylitic alteration, which is partially magnetite-destructive, which passes out into weak propylitic alteration and then into unaltered, moderately magnetic volcanics. For such a system, emplaced into magnetic intermediate-mafic igneous host rocks and exposed after removal by erosion of ~ 1 km of overburden, a strong central RTP high is surrounded by a relatively weak annular low over the phyllic zone, gradually returning to background levels over the propylitic zone (an "archery target" signature). For a completely buried system, however, the signature is basically an alteration low due to the large volume of magnetite-destructive alteration surrounding the deeply buried magnetic core.

  2. Scientists Debate Whether the Anthropocene Should Be a New Geological Epoch

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-01-01

    By about 2017 or 2018, scientists probably will have determined whether or not the Earth has entered into the "Anthropocene" epoch. Although many people are convinced that we are already living in the Anthropocene, that's the estimate for when a scientific review process could culminate in officially designating this potential new epoch of the Quaternary Period (roughly the past 2.6 million years) signified by profound human alteration to geological conditions and processes. The epoch would encompass—for the time being—a sliver of geological time separate rom the Holocene (roughly 12,000 years ago to the present), starting from perhaps the beginning of the Industrial Revolution, the end of World War II, or some other date determined to be a good marker to designate the beginning of the Anthropocene.

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

    USGS Publications Warehouse

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

    2011-01-01

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

  4. Geological exploration of Angola from Sumbe to Namibe: A review at the frontier between geology, natural resources and the history of geology

    NASA Astrophysics Data System (ADS)

    Masse, Pierre; Laurent, Olivier

    2016-01-01

    This paper provides a review of the Geological exploration of the Angola Coast (from Sumbe to Namibe) from pioneer's first geological descriptions and mining inventory to the most recent publications supported by the oil industry. We focus our attention on the following periods: 1875-1890 (Paul Choffat's work, mainly), 1910-1949 (first maps at country scale), 1949-1974 (detailed mapping of the Kwanza-Namibe coastal series), 1975-2000, with the editing of the last version of the Angola geological map at 1:1 million scale and the progressive completion of previous works. Since 2000, there is a renewal in geological fieldwork publications on the area mainly due to the work of university teams. This review paper thus stands at the frontier between geology, natural resources and the history of geology. It shows how geological knowledge has progressed in time, fueled by economic and scientific reasons.

  5. On the Geological History of Venus

    NASA Astrophysics Data System (ADS)

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

    2008-09-01

    mostly based on the analysis of data acquired by the Magellan mission: SAR images with 100-200 m resolution and the maps of topography, surface radar reflectivity, emissivity, roughness and gravity anomalies [1]. After initial analysis of the data summarized in [2, 3] several groups of researchers continued to study the geology and geophysics of the planet, resulting in numerous publications, some of which are referenced below. Very important for the studies emphasizing the geologic history of Venus was, and still is, a program of 1:5,000,000 geologic mapping coordinated by the US Geological Survey [4]. A recent summary of these studies can be found in [5]. Observations and analysis: All researchers in this study area analyze the same data sets and follow the same guidelines [4, 6] so geologic units identified by them and their time sequences are generally similar, although different researchers may name the same units differently and may interpret differently some details of local time sequences. Figure 1 shows a time sequence of geologic units suggested by [7, 8]: materials of tessera terrain (tt), densely fractured plains (pdf), fractured and ridged plains (pfr), shield plains (psh), plains with wrinkle ridges (pwr), lobate (pl) and smooth (ps) plains as well as materials of radar-dark craterassociated parabolas (cdp). These are material units. In addition, some researchers identify and map structural units. In Figure 1 examples of these are fracture belts (fb) and rifted terrain (rt). synchronous on a global scale. The first option can be visualized with Figure 1, suggesting that it is applicable for Venus globally. This option was suggested by Basilevsky and Head [e.g., 7, 8] as well as by Ivanov and Head [e.g., 9]. The second option, first clearly formulated by [10], can be visualized by the upper part of Figure 2 showing the situation in three different hypothetical geologic provinces on Venus. In these provinces the unit time sequences are the same: tt => pdf => pfr/RB => pwr, but morphologically similar units, for example, units pwr, are not synchronous between them: unit pwr in province 1 is generally synchronous with unit tt in province 2 and with unit pfr/RB in province 3. As it was mentioned in [7, 8], if geologic analysis and mapping are being done within spatially separated geologic provinces, the synchronous vs. not synchronous alternative cannot be resolved. But if the geologic analysis and mapping are done within large areas, which include several geologic provinces with nonsynchronous units sequences, then at the boundaries of the geologic provinces one should see contradictions in the units' age relations. These contradictions are visualized in the lower part of Figure 2: Tessera massif at the boundary between geologic provinces 1 and 2, from the province 1 side, should be formed as a result of tessera-forming deformation of material unit pwr, while from the province 2 side it is embayed by the unit pwr. Similar contradictions are observed in relations between tessera and unit pfr/RB in provinces 2 and 3. We have mentioned in several publications [e.g. 11] that very large (more than half) regions of the planet have been mapped and such contradictions were not met by us and not reported by other researchers. So we stated that this favored the synchronous option, but that time we could not global geologic mapping of Venus has been recently completed [12] and such contradictions have not been met, we can say that this mapping has proved that morphologically similar units occupying similar positions in the local time sequences are globally synchronous. Of course, each of units considered had been formed not instantaneously, but within some period of time. So we refer to the general synchroneity and minor overlapping in absolute time of formation between stratigraphically neighboring units as certainly possible. This global mapping of [12] led to the identification of geologic units and their time sequence that is very similar to those identified by [7, 8]; this allows us to return to that model of regional and global stratigraphy of Venus (Figure 3). This figure is almost identical to Figure 22 in [8] and differs only in the estimate of absolute age of the boundary between the Fortunian and Guineverian periods (1.2T here vs. 1.4T in [8]). The question of the estimation of absolute ages of geologic units is difficult for Venus because the atmosphere is too massive to allow craters smaller than a few kilometers in diameter to be formed on its surface. As a result, the total number of impact craters on Venus is only about 1,000, and this makes it possible to estimate more or less reliably only the mean surface age of Venus, and less reliably the mean ages of several large globally observed geologic units such as pwr, tt or pl. Crater count techniques used for other planetary bodies, which permits absolute dating and time correlations of units occupying relatively small areas, can not be used in this way on Venus. The existing estimates of mean absolute ages of the larger Venusian geologic units, such as pwr, tt or pl [e.g., 13-15], were obtained by counting craters on areally separated outcrops of these units and normalizing sums of crater numbers by the total areas of the unit outcrops. Although the results of such an approach were consistent with stratigraphies based on geologic analysis [e.g., 13-15] this was keeping in mind the possibility that in different part of the planet absolute ages of the same units may be significantly different. Now with the completion of the global geologic mapping of Venus, such inconsistencies are excluded. Another problem in crater-count-based estimations of absolute ages of the geological formations on Venus is related to uncertainties of a number of parameters crucial for reliable modeling to transition from number of craters to millions and billions of years: e.g., 1) the meteoroid flux in the vicinity of the planet Venus, 2) the physics of passing of meteoroids through the dense Venus atmosphere, and 3) cratering under the high atmospheric pressure. As a result of these uncertainties, even statistically reliable estimates of the mean surface age of Venus are not very certain: ~750 m.y., but any values between 300 m.y. and 1 b.y. are considered possible [16]. This is why researchers using crater statistics to estimate absolute ages of individual geologic units use fractions or multiples of the mean surface age of Venus, instead of millions or billions of years, designating it as T [e.g., 14, 15]. The new estimates based on the global geologic mapping of [12] suggest that ages of selected units (in T with 2 ? error bars) are: tt, 1.09 0.17; psh, 1.04 0.18; pwr, 1.05 0.12; pl, 0.54 0.19; rt, 0.63 0.26; confirming a new and more reliable basis for earlier estimates [13-15, 17-24]. This returns us to the conclusion made in [11]: the earlier suite of units (from heavily deformed tesserae through slightly deformed regional plains) occurred during a time period an order of magnitude shorter than the subsequent period (from the end of emplacement of the wrinkle-ridge network until the present). These results imply high global rates of endogenic (volcanic) activity during the first era (comparable to that of mid-oceanic-ridge volcanism of Earth) and much lower global rates of endogenic activity (by two orders of magnitude) for the second period (page 1015, abstract). Conclusions: As it follows from the above consideration, tectonic and volcanic processes in the beginning of the morphologically recognizable part of the geologic history of Venus (since tessera time) were rather active and resurfaced the entire planet. But then, after about 10-20% of the total duration of this part of history they rather sharply occurred sporadically and in separate spots and zones and affected only 15-20% of the Venus. For better understanding the rates of tectonic and volcanic processes on Venus, knowledge of which is crucial for working out reliable geodynamic models of the evolution of this planet, we need to have isotopic dating for absolute ages of major geologic units. The most promising in this respect is a sample return mission to Venus aiming to return to Earth material of unit pwr [25]. References: [1] Saunders R.S. et al. (1992) JGR, 97, 13067- 13091. [2] JGR (1992) 97, E8, E10. [3] Venus II (1997) Univ. Arizona Press. 1362 p. [4] Tanaka K.L. (1994) USGS Open-File Report 94-438. [5] Basilevsky A.T. & McGill G.E. (2007) In: Exploring Venus as a Terrestrial Planet, Geophysical Monograph 176. American Geophysical Union, Washington, DC. 23-44. [6] Wilhelms D. (1990) in Planetary Mapping, NY, 208-260. [7] Basilevsky A.T. & Head J.W. (1998) JGR, 103, 8531-8544. [8] Basilevsky A.T. & Head J.W. (2000) PSS, 48, 75-111. [9] Ivanov & Head J.W. (2001) JGR, 106, 17515-17566. [10] Guest J.E. & Stofan E.E. [1999] Icarus, 139, 55-66. [11] Basilevsky A.T. & Head J.W. (2002a) Geology, 30, 1015-1018. [12] Ivanov M.A. (2008) LPSC XXXIX, abs. # 1017. [13] Ivanov M. A. & Basilevsky A.T. (1993) GRL, 20, 2579-2582. [14] Namiki, N. & Solomon S.C. (1994) Science, 265, 929-933. [15] Price, M. & Suppe J. (1994) Nature, 372, 756-759. [16] McKinnon W. et al. (1997) Venus II, Univ. Arizona Press, 969-1014. [17] Gilmore M.S. et al. (1997) JGR, 102, 13,357-13,368. [18] Collins G.C. (1999) JGR, 104, 24,121-24,139. [19] Basilevsky A.T. et al. (1999) GRL, 26, 2593-2596. [20] Pivchenkova E.V. & Kryuchkov V.P. (2001) Vernadsky- Brown Microsymposium 34, abs. MS057. [21] Basilevsky A.T. & Head J.W. (2002b) JGR, 107, doi: 10.1029/2000JE001471. [22] Basilevsky A.T. & Head J.W. (2002c) JGR, 107, 10.1029/2001JE001584, 2002. [23] McGill G.E. (2004) Icarus, 172, 603-612. [24] Basilevsky A.T. & Head J.W. (2006) JGR, 111, CiteID E03006. [25] Basilevsky A.T. et al. (2006) PSS, 55, 2097-2112.

  6. Geology, mineralogy and fluid inclusion data from the Arapucan Pb Zn Cu Ag deposit, Canakkale, Turkey

    NASA Astrophysics Data System (ADS)

    Orgn, Yksel; Gltekin, Ali Haydar; Onal, Ayten

    2005-07-01

    The Arapucan Pb-Zn-Cu-Ag deposit occurs as hydrothermal veins in diabase and altered Triassic metasandstones adjacent to calc-alkaline intrusive igneous rocks. The deposit is an important commercial source of base metal in northwestern Turkey. Potential by-products are silver and gold. The geology of the area includes a Paleozoic metamorphic basement, Triassic sedimentary rocks with carbonate blocks, Tertiary granitoids and Neogene volcanics. The mineral assemblage includes galena, quartz, calcite, sphalerite, chalcopyrite and pyrite as well as minor bismuthinite, tetrahedrite, pyrolusite, hematite, scheelite, malachite, magnetite, limonite and rutile. Silver is associated with tetrahedrite. Early hydrothermal activity was responsible for the formation of three hypogene alteration types of decreasing intensity: silicification, sericitization and argillic alteration. These alteration styles show a rough spatial zonation. The ore stage clearly postdates hydrothermal alteration, as indicated by the occurrence of ore minerals in vuggy cavities and fractures in silica bodies. The deposit contains evidence of at least two periods of hypogene mineralization separated by a period of faulting. In addition to Pb, Zn, Cu, Ag and Au, the ores contain substantial quantities of W, Bi, Sb and Te. Average ? 34S values for galena and pyrite are -3.95 and -2.24, respectively, suggesting an igneous source for both the sulphur and metals. However, geological and geochemical interpretations suggest that at least some of the metals were leached from the metasandstones and diabases. Fluid inclusions in main-stage sphalerite homogenize at 229-384 C with salinities ranging from 1.7 to 18.5 eq.wt% NaCl. The deposits formed as the result of the interaction of two aqueous fluids: a higher-salinity fluid (probably magmatic) and a dilute meteoric fluid. The narrow range of ? 34S (galena and pyrite) values (-5.2 to -1.2 CDT) suggests that the sulphur source of the hydrothermal fluids was the same during deposition of the metals.

  7. 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 fs 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. For future missions to the Moon and Mars, the surface systems deployed must support the conduct of field geology if these endeavors are to be scientifically useful. This lecture discussed what field geology is all about.why it is important, how it is done, how conducting field geology informs many other sciences, and how it affects the design of surface systems and the implementation of operations in the future.

  8. Geologic guide to the island of Hawaii: A field guide for comparative planetary geology

    NASA Technical Reports Server (NTRS)

    Greeley, R. (Editor)

    1974-01-01

    With geological data available for all inner planets except Venus, we are entering an era of true comparative planetary geology, when knowledge of the differences and similarities for classes of structures (e.g., shield volcanoes) will lead to a better understanding of general geological processes, regardless of planet. Thus, it is imperative that planetologists, particularly those involved in geological mapping and surface feature analysis for terrestrial planets, be familiar with volcanic terrain in terms of its origin, structure, and morphology. One means of gaining this experience is through field trips in volcanic terrains - hence, the Planetology Conference in Hawaii. In addition, discussions with volcanologists at the conference provide an important basis for establishing communications between the two fields that will facilitate comparative studies as more data become available.

  9. Publications of the U.S. Geological Survey Branch of Atlantic Marine Geology: Calendar Year 1991

    USGS Publications Warehouse

    Mons-Wengler, Margaret C.; Oldale, Robert N.

    1992-01-01

    This [summary of] U.S. Geological Survey Open-File Report 92-585 contains a listing of publications authored or co-authored by members of the Branch of Atlantic Marine Geology during 1991. Results of Branch investigations are distributed in a variety of ways, including maps, journal articles, abstracts and U.S.G.S. publications. Copies of U.S.G.S. Open File Reports may generally be obtained from the author. Book publications can be obtained from U.S. Geological Survey, Books and Reports Sales, Federal Center, Box 25425, Denver, CO 80225. Copies of U.S.G.S. Maps may be obtained from the U.S. Geological Survey, Map Sales, Federal Center, Box 25286, Denver, CO 80225

  10. Art as Alterity in Education

    ERIC Educational Resources Information Center

    Zhao, Guoping

    2014-01-01

    In education, art has often been perceived as entertainment and decoration and is the first subject to go when there are budget cuts or test-score pressures. Drawing on Emmanuel Lvinas's idea of the primacy of radical alterity that breaks the totality of our being, enables self-transformation and ethics, and ensures community as a totality

  11. Altered Vision Near the Hands

    ERIC Educational Resources Information Center

    Abrams, Richard A.; Davoli, Christopher C.; Du, Feng; Knapp, William H., III; Paull, Daniel

    2008-01-01

    The present study explored the manner in which hand position may affect visual processing. We studied three classic visual attention tasks (visual search, inhibition of return, and attentional blink) during which the participants held their hands either near the stimulus display, or far from the display. Remarkably, the hands altered visual…

  12. Altered Vision Near the Hands

    ERIC Educational Resources Information Center

    Abrams, Richard A.; Davoli, Christopher C.; Du, Feng; Knapp, William H., III; Paull, Daniel

    2008-01-01

    The present study explored the manner in which hand position may affect visual processing. We studied three classic visual attention tasks (visual search, inhibition of return, and attentional blink) during which the participants held their hands either near the stimulus display, or far from the display. Remarkably, the hands altered visual

  13. Regional geology subprogram: Geological interpretation of ERTS imagery of the occidental region of Bolivia

    NASA Technical Reports Server (NTRS)

    Brockmann, C. E. (Principal Investigator); Ayllon, R. B.

    1973-01-01

    The author has identified the following significant results. Using ERTS-1 imagery, it is possible to delimit great lithological units, folds, lineaments, faults, and in lesser degree unconformities. In the morphological aspect, the images show clearly the relief necessary for geological interpretation. The ERTS-1 images are important for the preparation of the geological and tectonic map of Bolivia, on a 1:1 million scale, if conventional methods of work are used as a base.

  14. Mitochondrial alterations in Alzheimer's disease.

    PubMed

    Baloyannis, Stavros J

    2006-07-01

    Morphological alterations of mitochondria may be related to metabolic and energy deficiency in neurons in Alzheimer's disease and other neurodegenerative disorders. Mitochondrial dysfunction is also a hallmark of beta peptide induced neuronal toxicity in Alzheimer's disease. A general change in glucose utilization, increased oxidative stress, and Ca;{2+} deregulation are additional metabolic defects in the AD brain that may also be associated with defective mitochondrial function the result is a cycle of increased mitochondrial dysfunction causing increased oxidative damage until the cellular energy supply falls below the threshold for cellular survival. In a series of studies on the morphological and morphometric estimation of mitochondria in Alzheimer's disease, by electron microscopy we noticed substantial morphological and morphometric changes in the neurons of the hippocampus, the acoustic cortex, the frontal cortex, the cerebellar cortex, the climbing fibers, the thalamus, the globus pallidus, the red nucleus and the locus coeruleus. The morphological alterations consisted of considerable changes of the mitochondrial cristae, accumulation of osmiophilic material, and decrease of their size, in comparison with the normal controls. Mitochondrial alterations were particularly prominent in neurons, which showed loss of dendritic spines and abbreviation of the dendritic arborization. The ultrastructural study of large number of neurons in the thalamus and the red nucleus revealed that the mitochondrial alterations did not coexist with cytoskeletal pathology and accumulation of amyloid deposits, though they were prominent in neurons, which demonstrated fragmentation of the cisternae of the Golgi apparatus. Morphometric analysis showed that mitochondria are significantly reduced in Alzheimer's disease. The relationship between the site and extent of mitochondrial abnormalities and the synaptic alterations suggests an intimate and early association between these features in Alzheimer's disease. PMID:16873959

  15. Diabetic cardiomyopathy: electromechanical cellular alterations.

    PubMed

    Casis, O; Echevarria, E

    2004-07-01

    Diabetic patients show a higher incidence of cardiac arrhythmias, including ventricular fibrillation and sudden death. However, although diabetic cardiomyopathy is a frequent and important complication of diabetes mellitus, its physiological basis is not completely known. The electrocardiogram of diabetic patients shows several alterations from normal patterns, most of them related to the QT interval and T wave. Recently, different alterations in cardiac ionic currents have been described in myocytes isolated from diabetic hearts, mainly a reduction in potassium repolarizing currents. Three different mechanisms could be involved in these alterations. First, direct metabolic alterations of the cardiac myocyte, such as impaired activity of protein kinases and phosphatases, intracellular pH regulation, intracellular calcium handling, and others. Second, impaired support of extra cardiac factors regulating cardiac activity, such as sympathetic regulation of heart rate and contractility. Thus, diabetic autonomic neuropathy leads to diminished noradrenaline release in cardiac ventricle in response to standing, exercise or cold stress. Besides, diabetic cardiomyopathy reduces cardiac myocyte response to acute noradrenaline exposure and finally, impairs support of different trophic factors responsible for the regulation of ionic channel expression. Thus, basal noradrenaline release in the ventricles, necessary to maintain adequate potassium channel expression, is reduced by sympathetic neuropathy. Moreover, the levels of insulin and other trophic factors required for the maintenance of adequate ionic channel expression are also altered in diabetic patients. Therefore, different physiopathological mechanisms are involved in diabetic cardiomyopathy. Thus, further research is needed in order to prevent the development of this long-term complication, and to improve the pharmacological management of diabetic patients. PMID:15320822

  16. Assessment of effectiveness of geologic isolation systems: the AEGIS geologic simulation model

    SciTech Connect

    Foley, M.G.; Petrie, G.M.

    1981-02-01

    Assessment of the post-closure performance of a nuclear waste repository has two basic components: the identification and analysis of potentially disruptive sequences and the pattern of geologic events and processes causing each sequence, and the identification and analysis of the environmental consequences of radionuclide transport and interactions subsequent to disruption of a repository. The AEGIS Scenario Analysis Task is charged with identifying and analyzing potenially disruptive sequences of geologic events and processes. The Geologic Simulation Model (GSM) was developed to evaluate the geologic/hydrologic system surrounding an underground repository, and describe the phenomena that alone, or in concert, could perturb the system and possibly cause a loss of repository integrity. The AEGIS approach is described in this report. It uses an integrated series of models for repository performance analysis; the GSM for a low-resolution, long-term, comprehensive evaluation of the geologic/hydrologic system, followed by more detailed hydrogeologic, radionuclide transport, and dose models to more accurately assess the consequences of disruptive sequences selected from the GSM analyses. This approach is felt to be more cost-effective than an integrated one because the GSM can be used to estimate the likelihoods of different potentially disruptive future evolutionary developments within the geologic/hydrologic system. The more costly consequence models can then be focused on a few disruptive sequences chosen for their representativeness and effective probabilities.

  17. Reconciling Changes to the Geologic Time Scale, in the U.S. Geologic Names Lexicon

    NASA Astrophysics Data System (ADS)

    Soller, D. R.; Stamm, N. R.

    2014-12-01

    The U.S. Geologic Names Lexicon ("Geolex", http://ngmdb.usgs.gov/Geolex/), is a standard reference for the Nation's stratigraphic nomenclature. Geolex's content is drawn from the literature published since the late 1800's. Since that time, modifications to the geologic time scale have been significant, particularly in recent decades (e.g., the Ordovician, Carboniferous, Permian, and Quaternary), owing in part to more precise biostratigraphic zonations and advances in isotopic dating techniques. Because the definitions of geologic time intervals have been modified as more information is gathered, interpreted, and published, the geologic age of a unit as stated in a report published in, for example, 1950, may be different according to today's time scale. In order to ensure that people can search Geolex for geologic units according to today's time scale, we have updated to the modern time scale the age estimates for many geologic units. These updated age estimates are shown in Geolex's "Unit Summary" pages; the ages as originally determined are preserved in the synopsis for each publication. This presentation will focus on our methodology.

  18. Comprehensive geological history of asteroid Vesta

    NASA Astrophysics Data System (ADS)

    Marchi, S.; Williams, D. A.; McSween, H. Y.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

    2014-07-01

    In this paper, we present a time-stratigraphic scheme and geologic time scale for the asteroid Vesta, based on global geologic mapping and other analyses of NASA Dawn spacecraft data, supplemented with insights gained from laboratory studies of howardite-eucrite-diogenite (HED) meteorites and geophysical modeling. We identify four geologic time periods for Vesta, associated with the formation of major impacts: Pre-Veneneian, Veneneian, Rheasilvian, and Marcian. The Pre-Veneneian period covers the time from the formation of Vesta (a few Myr after the formation of the first solids in the proto-solar disk that took place at 4.57 Gyr ago) up to the Veneneia impact event. The Veneneian period covers the time between the Veneneia and Rheasilvia impact events. The Rheasilvian period covers the time between the formation of Rheasilvia and Marcia craters, and the Marcian period covers the time between the formation of Marcia crater until the present. Absolute ages for the boundaries of these periods have been derived by applying two crater chronologies, one based on the current understanding on asteroidal impact rate at Vesta and its evolution over time; the other is based on an extrapolated version of the lunar crater chronology. While the ages and durations of the various periods change considerably depending on which chronology is applied, the relative age of the Veneneia and Rheasilvia impacts is unambiguously determined by superposition relationships, while the formation of the Marcia crater clearly represents the youngest major geologic event on Vesta. Absolute model ages allow us to relate Vesta geologic time periods to key features of the main asteroid belt, such as the formation of the large vestan dynamical family. The formation ages of the Vesta's family can be assessed with independent means, such as by measuring the spreading of the family members in orbital space, and therefore provide a benchmark for both theoretical models of asteroid family evolution and crater chronology. Absolute ages also provide an important framework to interpret impact-generated radiometric ages of HEDs. Our proposed four-period geologic time scale for Vesta is consistent with those developed for other terrestrial bodies, such as the Moon, Mars, Earth, and Mercury, and allow us to place Vesta in the context of major phases of the evolution of the solar system, such as the Late Heavy Bombardment, a period of intense bombardment in the inner solar system triggered by the migration of the giant planets.

  19. Working towards a European Geological Data Infrastructure

    NASA Astrophysics Data System (ADS)

    van der Krogt, Rob; Hughes, Richard; Pedersen, Mikael; Serrano, Jean-Jacques; Lee, Kathryn A.; Tulstrup, Jrgen; Robida, Franois

    2013-04-01

    The increasing importance of geological information for policy, regulation and business needs at European and international level has been recognized by the European Parliament and the European Commission, who have called for the development of a common European geological knowledge base. The societal relevance of geoscience data/information is clear from many current issues such as shale gas exploration (including environmental impacts), the availability of critical mineral resources in a global economy, management and security with regard to geohazards (seismic, droughts, floods, ground stability), quality of (ground-)water and soil and societal responses to the impacts of climate change. The EGDI-Scope project responds to this, aiming to prepare an implementation plan for a pan-European Geological Data Infrastructure (EGDI), under the umbrella of the FP7 e- Infrastructures program. It is envisaged that the EGDI will build on geological datasets and models currently held by the European Geological Surveys at national and regional levels, and will also provide a platform for datasets generated by the large number of relevant past, ongoing and future European projects which have geological components. With European policy makers and decision makers from (international) industry as the main target groups (followed by research communities and the general public) stakeholder involvement is imperative to the successful realization and continuity of the EGDI. With these ambitions in mind, the presentation will focus on the following issues, also based on the first results and experiences of the EGDI-Scope project that started mid-2012: The organization of stakeholder input and commitment connected to relevant 'use cases' within different thematic domains; a number of stakeholder representatives is currently involved, but the project is open to more extensive participation; A large number of European projects relevant for data delivery to EGDI has been reviewed; what can we conclude and what is the way forward? The project has evaluated relevant existing interoperable infrastructures revealing a typology of infrastructures that may be useful models for the EGDI; Planning for the EGDI also need to be integrated with other relevant international initiatives and programs such as GMES, GEO and EPOS, and with legally binding regulations like INSPIRE. The outcomes of these relevant evaluations and activities will contribute to the implementation plan for the EGDI including the prioritization of relevant datasets and the most important functional, technical (design, use of standards), legal and organizational requirements.

  20. A Study of the Education of Geology

    NASA Astrophysics Data System (ADS)

    Berglin, R. S.; Baldridge, A. M.; Buxner, S.; Crown, D. A.

    2013-12-01

    An Evaluation and Assessment Method for Workshops in Science Education and Resources While many professional development workshops train teachers with classroom activities for students, Workshops in Science Education and Resources (WISER): Planetary Perspectives is designed to give elementary and middle school teachers the deeper knowledge necessary to be confident teaching the earth and space science content in their classrooms. Two WISER workshops, Deserts of the Solar System and Volcanoes of the Solar System, place an emphasis on participants being able to use learned knowledge to describe or 'tell the story of' a given rock. In order to understand how participants' knowledge and ability to tell the story changes with instruction, we are investigating new ways of probing the understanding of geologic processes. The study will include results from both college level geology students and teachers, focusing on their understanding of geologic processes and the rock cycle. By studying how new students process geologic information, teachers may benefit by learning how to better teach similar information. This project will help to transfer geologic knowledge to new settings and assess education theories for how people learn. Participants in this study include teachers participating in the WISER program in AZ and introductory level college students at St. Mary's College of California. Participants will be videotaped drawing out their thought process on butcher paper as they describe a given rock. When they are done, they will be asked to describe what they have put on the paper and this interview will be recorded. These techniques will be initially performed with students at St. Mary's College of California to understand how to best gather information. An evaluation of their prior knowledge and previous experience will be determined, and a code of their thought process will be recorded. The same students will complete a semester of an introductory college level Physical Geology course and then complete the assessment process, with the same rock again. Data will be compared to see how the thought process has changed. By studying the initial thought process, teachers can meet students at their level. At the end of the student research, this project will also be applied to elementary and middle school teachers in Tucson, Arizona at WISER workshops. This study will draw conclusions on how participants' thought processes change through WISER-type instruction.

  1. Using Student-Created Metaphors to Comprehend Geologic Time.

    ERIC Educational Resources Information Center

    Ritger, Scott David; Cummins, Robert Hays

    1991-01-01

    Presents an activity for introducing students to geologic time. Students choose their own metaphor for geologic time, selecting milestones in Earth history and scaling these events to their metaphors.(PR)

  2. Teaching Igneous Geology in Physical Geography: Some Recommendations.

    ERIC Educational Resources Information Center

    Powell, William E.

    1982-01-01

    The most common igneous minerals and their diagnostic properties, which the author considers the most significant and pragmatic aspect of igneous geology for physical geography students, are discussed. The nature of igneous geology is also examined. (RM)

  3. The United States Geological Survey in Alaska; accomplishments during 1983

    USGS Publications Warehouse

    Bartsch-Winkler, S., (Edited By); Reed, K.M.

    1985-01-01

    This circular contains short reports about many of the geologic studies carried out in Alaska by the U.S. Geological Survey and cooperating agencies during 1983. The topics cover a wide range in scientific and economic interest.

  4. Terrestrial and Lunar Geological Terminology for Non-Geoscientists

    NASA Technical Reports Server (NTRS)

    Schrader, Christian M.

    2009-01-01

    This slide presentation reviews several geologic concepts applicable to lunar geology with particular interest in creating lunar regolith simulant. Fundamental ways in which the Moon differs from the Earth. Concepts that are described in detail are: minerals, glass, and rocks.

  5. GEOLOGY - NEUSE RIVER WATERSHED, NC (1:250,000 SCALE)

    EPA Science Inventory

    The North Carolina Department of Environment, Health, and Natural Resources, Division of Land Resources, NC Geological Survey, in cooperation with the North Carolina Center for Geographic Information and Analysis, developed the digital version of the Geology of North Carolina. T...

  6. Summary on Several Key Techniques in 3D Geological Modeling

    PubMed Central

    2014-01-01

    Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized. PMID:24772029

  7. Principle and geometric precision of photographic geological logging of tunnels

    NASA Astrophysics Data System (ADS)

    Li, Hao; Zhang, Rong-Chun; Yang, Biao; Wu, Ming-Fei

    2014-01-01

    Considering the problem of engineering geological logging technique by means of sketching at the work site, this paper presents a photographic geological logging technique based on photogrammetry as well as engineering geology. The principles, methods, and working process have been discussed, and the photographic geological logging precision of a tunnel and its estimation method have been researched. The theoretical and experimental analysis shows that the precision of the digital unfolded image map of tunnel automatically generated by the photographic geological logging method is sufficient for serving as the logging base map. Besides, the measurement precision of unfolded images or stereopairs meets the requirements of geological attitude measurement. The new technique of photographic geological logging proposed in this paper is expected to replace the current sketch way of engineering geological logging on site, with the operation mode converted from manual operation to computer-aided operation and informatized management.

  8. Televising Microscopic Images for Instructional Use in Geology.

    ERIC Educational Resources Information Center

    Carter, Bruce

    1979-01-01

    Described are the uses of a television camera mounted on a microscope. Findings indicate the effectiveness of televised microscopy for instruction in geology. Particular usefulness was shown for teaching basic principles of microscopy and geology in introductory courses. (RE)

  9. Digital geologic map and GIS database of Venezuela

    USGS Publications Warehouse

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

    2006-01-01

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

  10. "Geological metadata" to share field geological knowledge and related map generalizations

    NASA Astrophysics Data System (ADS)

    Balestro, G.; Bini, S.; Piana, F.; Tallone, S.

    2009-04-01

    Sharing of geological information on the Web is rapidly increasing and steadily supported by ongoing IT innovation. Since GIS databases, metadata (MD) and spatial data infrastructures are tools gradually used in Earth science, concepts such as clearness, usefulness, quality and use constraints of web disseminated data, become matters of interest for the communities of geologists In field geosciences, the possibility to share actually understandable information is constrained by the peculiar approach adopted in knowledge acquisition (field survey) and knowledge representation (geological maps). Datasets comprehend both measurements/observations and applications of conceptual models, achieved with a large use of implicit knowledge that characterizes the analysis, processing and interpretation of original data. Field geological knowledge is biased by geologists' subjectivity and constrained by different type of uncertainties coming from capture methods, interpretative models and map generalizations. Shared information need thus specifications about i) the intended meanings of adopted concepts, ii) the physical paths (i.e. the operational steps concerning data acquisition on the field), iii) the knowledge paths (interpretation steps performed on data). Field geological data have to be organized in conceptually-driven systems, where explained information get retraceable. An attempt to reach this goal has been recently carried out by CNR IGG TO working group in the IDE-Univers project, by setting up a geoportal (http://www.geoportal-idec.net/ideunivers/), where geological information are described through ISO19915 MD standard and shared through WMS technology. The CNR IGGTO Server contains field data and related geological maps mainly stored in the frame of the CARG project (1:50000 Geological Map of Italy). Our strategy is to get this information conceptually described, using the Geographic MD international standard for the geological context, in order to give geological interpretations in an explicit format. These "geological metadata" have been compiled mainly as regard the "Identification" and the "Data Quality" classes. The Abstract element (Identification class) explains the criteria on which data are interpreted and the meaning of them, giving the peculiarities of interpreted features. The Resource Locator element (Identification class) allows to link datasets with conceptual supplemental information (conceptual schemas), where concepts and methods adopted in the acquisition of knowledge are given. The Lineage element (Data Quality class) gives the different process steps performed on data, specifying the provenance of interpreted features and making them retraceable. A further improvement of the readability of the information stored in the CNR IGGTO geoportal, is presently carried out in the frame of GIIDA project (an initiative to implement the Spatial Information Infrastructure of CNR for Environmental and Earth Observation data) by development of Wiki sites linkable to the MD sheets.

  11. Digital geologic map of Clinton Quadrangle, west-central Oklahoma

    USGS Publications Warehouse

    Cederstrand, J.R.

    1997-01-01

    This data set consists of digital data and accompanying documentation for the surficial geology of the 1:250,000-scale Clinton quadrangle. The original data are from the Geologic Map, sheet 1 of 4, included in the Oklahoma Geological Survey publication, Reconnaissance of the water resources of the Clinton quadrangle, west-central Oklahoma, Hydrologic Atlas 5, Carr and Bergman, 1976. The geology was compiled by J.E. Carr, 1972, and R.O. Fay, 1975.

  12. A digital geologic map database for the state of Oklahoma

    USGS Publications Warehouse

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

    2003-01-01

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

  13. Applicability of ERTS-1 to Montana geology

    NASA Technical Reports Server (NTRS)

    Weidman, R. M. (Principal Investigator); Alt, D. D.; Berg, R.; Johns, W.; Flood, R.; Hawley, K.; Wackwitz, L.

    1976-01-01

    The author has identified the following significant results. Late autumn imagery provides the advantages of topographic shadow enhancement and low cloud cover. Mapping of rock units was done locally with good results for alluvium, basin fill, volcanics, inclined Paleozoic and Mesozoic beds, and host strata of bentonite beds. Folds, intrusive domes, and even dip directions were mapped where differential erosion was significant. However, mapping was not possible for belt strata, was difficult for granite, and was hindered by conifers compared to grass cover. Expansion of local mapping required geologic control and encountered significant areas unmappable from ERTS imagery. Annotation of lineaments provided much new geologic data. By extrapolating test site comparisons, it is inferred that 27 percent of some 1200 lineaments mapped from western Montana represent unknown faults. The remainder appear to be localized mainly by undiscovered faults and sets of minor faults or joints.

  14. Geological interpretation of a Gemini photo

    USGS Publications Warehouse

    Hemphill, William R.; Danilchik, Walter

    1968-01-01

    Study of the Gemini V photograph of the Salt Range and Potwar Plateau, West Pakistan, indicates that small-scale orbital photographs permit recognition of the regional continuity of some geologic features, particularly faults and folds that could he easily overlooked on conventional air photographs of larger scale. Some stratigraphic relationships can also be recognized on the orbital photograph, but with only minimal previous geologic knowledge of the area, these interpretations are less conclusive or reliable than the interpretation of structure. It is suggested that improved atmospheric penetration could be achieved through the use of color infrared film. Photographic expression of topography could also be improved by deliberately photographing some areas during periods of low sun angle.

  15. Medium Frequency Pseudo Noise Geological Radar

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Byerly, Kent A. (Inventor); Amini, B. Jon (Inventor)

    2003-01-01

    System and methods are disclosed for transmitting and receiving electromagnetic pulses through a geological formation. A preferably programmable transmitter having an all-digital portion in a preferred embodiment may be operated at frequencies below 1 MHz without loss of target resolution by transmitting and over sampling received long PN codes. A gated and stored portion of the received signal may be correlated with the PN code to determine distances of interfaces within the geological formation, such as the distance of a water interfaces from a wellbore. The received signal is oversampled preferably at rates such as five to fifty times as high as a carrier frequency. In one method of the invention, an oil well with multiple production zones may be kept in production by detecting an approaching water front in one of the production zones and shutting down that particular production zone thereby permitting the remaining production zones to continue operating.

  16. Geologic hazards of the Wasatch Front, Utah

    USGS Publications Warehouse

    Hylland, M.D.; Black, B.D.; Lowe, Mark

    1997-01-01

    The results of recent and ongoing research into six significant geologic hazards of the Wasatch Front region will be summarized on this field trip, including: (1) surface fault rupture on the Salt Lake City segment of the Wasatch fault zone; (2) seismic site response in the Salt Lake Valley, including ground shaking and liquefaction; (3) liquefaction-induced landsliding at the Farmington Siding landslide complex; (4) lake flooding along the shores of Great Salt Lake; (5) debris-flow deposition on alluvial fans at the base of the Wasatch Range; and (6) landsliding in the Ogden area. The trip will provide an opportunity to discuss the scientific, engineering, and administrative aspects involved in geologic-hazard evaluation in this rapidly growing region.

  17. Evaluation of thermal data for geologic applications

    NASA Technical Reports Server (NTRS)

    Kahle, A. B.; Palluconi, F. D.; Levine, C. J.; Abrams, M. J.; Nash, D. B.; Alley, R. E.; Schieldge, J. P.

    1982-01-01

    Sensitivity studies using thermal models indicated sources of errors in the determination of thermal inertia from HCMM data. Apparent thermal inertia, with only simple atmospheric radiance corrections to the measured surface temperature, would be sufficient for most operational requirements for surface thermal inertia. Thermal data does have additional information about the nature of surface material that is not available in visible and near infrared reflectance data. Color composites of daytime temperature, nighttime temperature, and albedo were often more useful than thermal inertia images alone for discrimination of lithologic boundaries. A modeling study, using the annual heating cycle, indicated the feasibility of looking for geologic features buried under as much as a meter of alluvial material. The spatial resolution of HCMM data is a major limiting factor in the usefulness of the data for geologic applications. Future thermal infrared satellite sensors should provide spatial resolution comparable to that of the LANDSAT data.

  18. Overview: Gas hydrate geology and geography

    SciTech Connect

    Malone, R.D.

    1993-01-01

    Several geological factors which are directly responsible for the presence or absence of gas hydrates have been reviewed and are: tectonic position of the region; sedimentary environments; structural deformation; shale diapirism; hydrocarbon generation and migration; thermal regime in the hydrate formation zone (HFZ); pressure conditions; and hydrocarbon gas supply to the HFZ. Work on gas hydrate formation in the geological environment has made significant advances, but there is still much to be learned. Work is continuing in the deeper offshore areas through the Ocean Drilling Program, Government Agencies, and Industry. The pressure/temperature conditions necessary for formation has been identified for various compositions of natural gas through laboratory investigations and conditions for formation are being advanced through drilling in areas where gas hydrates exist.

  19. Miranda's Geologic History (variety of terrain)

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Miranda reveals a complex geologic history in this view, acquired by Voyager 2 on Jan. 24, 1986, around its close approach to the Uranian moon. At least three terrain types of different age and geologic style are evident at this resolution of about 700 meters (2,300 feet). Visible in this clear-filter, narrow-angle image are, from left: (1) an apparently ancient, cratered terrain consisting of rolling, subdued hills and degraded medium-sized craters (2) a grooved terrain with linear valleys and ridges developed at the expense of, or replacing, the first terrain type: and (3) a complex terrain seen along the terminator, in which intersecting curvilinear ridges and troughs are abruptly truncated by the linear, grooved terrain. Voyager scientists believe this third terrain type is intermediate in age between the first two. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  20. Modeling geological objects with the XML Schema

    NASA Astrophysics Data System (ADS)

    Babaie, Hassan A.; Babaei, Abbed

    2005-11-01

    Interchange, storage, and management of geological data require the development of knowledge-based, standardized vocabularies and data structures. Concepts modeled and designed with the Unified Markup Language (UML), can be mapped into XML Schema Definition Language (XSDL) to compose modular markup languages for each discipline. Developing such efficient, intra-disciplinary, modular and reusable components, based on the XSDL namespace facility and the principles of object-oriented design, reduces redundancy, increases efficiency, scalability, and extensibility, and simplifies the maintenance and future extension of the code. This paper discusses the best practices of composition and reuse of modular intra-disciplinary components by applying XML Schema namespace syntax. In addition to several small examples given for a variety of geological cases, the paper constructs a UML conceptual model and markup language, applying an XML-type library, for a component of the plate tectonics knowledge base (TectonicsML) that deals with the divergent plate boundary.