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1

Hydrothermal carbonates in altered wall rocks at the Uwamuki Kuroko deposits, Japan  

Microsoft Academic Search

Magnesite, siderite and dolomite are characteristic alteration minerals occurring in Miocene hanging wall rocks of dacitic\\u000a composition which host the Kuroko orebodies. These carbonates generally occur in a more stratigraphically upper horizon than\\u000a chlorite alteration zone surrounding the orebodies. The Mg\\/(Mg+Fe) ratios of the carbonates decrease from the central alteration\\u000a zone to marginal zone. The Mg\\/(Mg+Fe) ratios of carbonates and

N. Shikazono; M. Hoshino; M. Utada; M. Nakata; A. Ueda

1998-01-01

2

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

Microsoft Academic Search

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

Aberra Getahun; Mark H. Reed; Robert Symonds

1996-01-01

3

Stable isotope studies of stratabound ores and wall rock alterations at Killingdal Mine, central Norwegian caledonides  

SciTech Connect

/sup 34/S//sup 32/S and /sup 18/O//sup 16/O ratios have been measured on the massive sulfide ores and the adjacent metamorphic country rocks at the Killingdal Mine. Coexisting pyrite, chalcopyrite and sphalerite in the ores and country rocks show small but identical sulfur isotope fractionations (..delta..py-sp = 0.1-0.8, ..delta..py-cp = 0.41-1.1) suggesting a close approach to isotopic equilibrium at 480-505/sup 0/C. The delta/sup 34/S values of sulfides in the ores (-1.4 to +2.6) are distinct from those in the adjacent metamorphic country rocks (+1.8 to +3.7) suggesting that a small sulfur isotope fractionation occurred during the sulfur-silicate reactions. Material balance calculation also suggest that desulfurization of pyrite to pyrrhotite produced delta/sup 34/S enrichment of about 1.8 per thousands w.r.t. the original pyrite. delta/sup 18/O values in the silicate wall rocks are: phyllites 9.5-11.9, greenstones 7.7-8.1, altered greenstones 6.2-8.4, chlorite schists 5.8-9.5, and quartz-muscovite schists 8.1-12.4. The quartz-muscovite schists show two distinct isotopic groupings which fall within the range shown by the greenstones and phyllites, respectively. No isotopic anomaly was observed in the alteration halos in the country rocks. Analyses of coexisting quartz (delta=9.1-10.9) and muscovite (delta=5.9-7.2) in the q-m schists yield isotopic temperatures ranging from 440 to 510/sup 0/C, similar to those obtained from the massive ores. The delta/sup 18/O values of the aqueous fluid associated with the q-m schists were calculated to be from 5.6 to 7.4 per thousands suggesting its derivation from a magmatic source.

Shieh, Y.N.; Rui, I.J.; Kullerud, G.

1985-01-01

4

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

NASA Astrophysics Data System (ADS)

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 ~ 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 (quartz + biotite ± muscovite + plagioclase + microcline) 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. On the basis of a constant Al reference frame, calculations indicate a net volume loss of 21-34% within one centimeter of the vein with little or no volume loss further from the vein. Fluid-rock interaction modeling suggests that between one and four equivalent masses of fluid interacted chemically with the most altered mineral assemblages. In addition, greater than one equivalent mass of reactive fluid penetrated to distances of at least 5 cm from the vein contact.

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

1988-07-01

5

The significance of geological and zircon age data derived from the wall rocks of the Ailao Shan–Red River Shear Zone, NW Vietnam  

NASA Astrophysics Data System (ADS)

This paper offers new evidence on whether the Ailao Shan–Red River Shear Zone of NW Vietnam is part of a suture zone between two continental blocks (the IndoChina Block and the South China Block) or whether it is itself of intracontinental origin, developed within the South China margin. To help clarify the role that the Ailao Shan–Red River Shear Zone plays in South China tectonic reconstructions, we gathered new whole-rock geochemistry, structural field data, and zircon U–Pb (SHRIMP) ages from granites, rhyodacites, and migmatites that occur within geological units adjacent to both the SW and NE sides of the Red River Fault Zone, a segment of the larger shear zone. The new zircon ages show that both walls of the Red River Fault Zone contain metamorphic and intraplate A-type granitoid rocks of Late Permian–Early Triassic age (263–240 Ma) and are of Indosinian origin. In the SW wall, the Fan Si Pan complex is a Neoproterozoic basement of metagranites and metasediments that was intruded by Late Permian (˜260 Ma), peralkaline, A-type granites and by subalkaline, A-type, biotite granite of Eocene age (˜35 Ma), containing xenoliths of gneissified Permian granitoids. The two intrusive episodes were separated by regional tectonic deformations occurring within a transpressional regime of a NW/W-vergent thrusting with a left-lateral oblique component, that was associated with greenschist to amphibolite facies metamorphism, presumably also of Eocene age (˜50–35 Ma), and that may have been related to the left-lateral movement on the Ailao Shan–Red River Shear Zone. In the NE wall, the Lo Gam complex is a Neoproterozoic basement (˜767 Ma) that was repeatedly subjected to tectonothermal activity throughout the Palaeozoic (at ˜450–420 Ma, ˜350 Ma, ˜265 Ma), ending in the Early Triassic (˜248 Ma). There was no thermal overprint during the Cenozoic. In this wall, a significant part of the Permo-Triassic thermotectonism was ductile shearing that was concentrated along dextral, strike-slip NW-trending zones in the vicinity the Ailao Shan–Red River Shear Zone but that became a type of NE/N-ward extensional/contractional, regional movement further away of it. An early shearing on the Ailao Shan–Red River Shear Zone may date back to the Permo-Triassic and we consider that this probably originated in a continental fault zone initiated in the hinterland of the oblique Indosinian collisional zone.

?ela?niewicz, Andrzej; Hòa, Tr?n Tr?ng; Larionov, Alexander N.

2013-09-01

6

Red-staining of the wall rock and its influence on the reducing capacity around water conducting fractures  

Microsoft Academic Search

Red-staining and alteration of wall rock is common around water conducting fractures in the Laxemar–Simpevarp area (SE Sweden), which is currently being investigated by the Swedish Nuclear Fuel and Waste Management Co. (SKB) in common with many other places. Red-staining is often interpreted as a clear sign of oxidation but relevant analyses are seldom performed. The area is dominated by

Henrik Drake; Eva-Lena Tullborg; Hans Annersten

2008-01-01

7

Thermal limitations on incorporation of wall rock into magma  

NASA Astrophysics Data System (ADS)

Incorporation of solid wall rocks is an oft-cited process in the evolution of magmas, but this process is severely limited by the energy required to dissolve xenoliths. Disaggregation without melting has been proposed as an alternative process for incorporating xenoliths into magma because disaggregation avoids expending the energy required for melting. Analysis of these processes using enthalpy-composition diagrams shows that both processes rapidly lead to high crystal contents in the hybrid magma. For example, incorporation of 25% granite at 400 °C into basalt magma at 1125 °C produces a hybrid magma at 1050 °C with >50% crystals; if the granite disaggregates without melting, the crystal content is 65% 70%. Once the crystal content reaches ˜50% the viscosity of the magma is too high to allow further magma movement or xenolith incorporation. Thus, both processes are self-limiting and probably restricted in natural systems to at most a few tens of percent incorporation of xenoliths.

Glazner, Allen F.

2007-04-01

8

Kimberlite Wall Rock Fragmentation: Venetia K08 Pipe Development  

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

9

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

10

Global geologic context for rock types and surface alteration on Mars  

USGS Publications Warehouse

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

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

2004-01-01

11

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

Microsoft Academic Search

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.

Matthew Chojnacki; Brian M. Hynek

2008-01-01

12

Emplacement of multiple magma sheets and wall rock deformation: Trachyte Mesa intrusion, Henry Mountains, Utah  

Microsoft Academic Search

A detailed structural and rock magnetic study of the Trachyte Mesa intrusion and deformed sedimentary wall rocks, Henry Mountains, Utah, indicates that the intrusion grew vertically and horizontally by the accumulation of multiple horizontal magma sheets. 2–3cm thick shear zones recognized by intensely cataclasized plagioclase phenocrysts define the contact between sheets. Sheets have bulbous and \\/ or steep frontal terminations

Sven Morgan; Amy Stanik; Eric Horsman; Basil Tikoff; Michel de Saint Blanquat; Guillaume Habert

2008-01-01

13

Non-Darcy Effects for Fluid Flow in a Rough-Walled Rock Fracture  

Microsoft Academic Search

An experimental and computational study has been conducted of fluid flow in a rough-walled rock fracture, with emphasis on deviations from Darcy's law in the regime of Reynolds numbers greater than unity. First, profiles of a fracture in a red Permian sandstone were measured with a profilometer, to within +\\/- 2 microns in elevation, at intervals of every twenty microns

A. H. Al-Yaarubi; C. C. Pain; C. A. Grattoni; R. W. Zimmerman

2002-01-01

14

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)

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.

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

2012-04-01

15

Geology.  

National Technical Information Service (NTIS)

Geologic history and geographic distribution of Central New York's surface and subsurface mineral resources are described. Present and potential economic uses are identified; abandoned, semi-active, and active extraction sites are depicted; and resources ...

J. F. Davis

1970-01-01

16

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

NASA Astrophysics Data System (ADS)

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

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

2003-06-01

17

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

SciTech Connect

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.

Reed, M.H. (Univ. of Oregon, Eugene, OR (United States). Dept. of Geological Sciences)

1993-04-01

18

Using empirical geological rules to reduce structural uncertainty in seismic interpretation of faults  

Microsoft Academic Search

Good seismic interpretation of faults should include a workflow that checks the interpretation against known structural properties of fault systems. Estimates of wall-rock strains provide one objective means for discriminating between correct and incorrect structural interpretations of 2D and 3D seismic data – implied wall-rock strain should be below a geologically plausible maximum. We call this the strain minimisation approach. Drawing

Brett Freeman; Peter J. Boult; Graham Yielding; Sandy Menpes

2010-01-01

19

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

20

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

SciTech Connect

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.

Pruess (ed), K.; Tsang, Y.W.

1989-09-01

21

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

Microsoft Academic Search

Cored bombs, a kind of pyroclast consisting of a lithic core surrounded by a chilled shell of juvenile material, record the thermal interaction of magma with wall rocks. We performed textural analysis of cored bombs, solid–melt heat-transfer theoretical modelling, and high-temperature coating experiments to put temporal and intensity constraints on the thermal interaction of potassic magma feeder systems with carbonate

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

2010-01-01

22

The stable isotope geochemistry of acid sulfate alteration  

USGS Publications Warehouse

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

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

1992-01-01

23

Alteration of oceanic crust and geologic cycling of chlorine and water  

Microsoft Academic Search

We report new estimates of transport rates for H 2 O and Cl between the mantle and surface reservoirs. Our estimates take into consideration alteration of oceanic crust, especially that of plutonic rocks, and possible subduction of sediments. The effect of (hydrothermal) alteration on the Cl budget seems to be negligible, but the effect on the H 2 O budget

Emi Ito; David M. Harris; Alfred T. Anderson Jr.

1983-01-01

24

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

SciTech Connect

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.

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

1991-01-01

25

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

NASA Astrophysics Data System (ADS)

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

Torrez, G.; Putirka, K. D.

2010-12-01

26

Geological and geochemical constraints on genesis of the Liziyuan gold-dominated polymetal deposit, western Qinling orogen, central China  

Microsoft Academic Search

The Liziyuan gold deposit, located on the northern margin of the western Qinling orogen (WQO), consists of five mineralized sites hosted by metavolcanic rocks, and one hosted by the Tianzishan monzogranite. Orebodies mainly occur as lenticular veins along NW-striking dextral ductile strike–slip shear zones. Major wall rock alteration includes silicification, pyritization, and carbonation, progressively increasing in intensity towards the orebodies.

Tao Yang; Laimin Zhu; Guowei Zhang; Fei Wang; Rukun Lu; Jichao Xia; Yongqiang Zhang

2012-01-01

27

GEOLOGIC FRAMEWORK OF JURASSIC RESERVOIR ROCKS IN THE DIXIE VALLEY GEOTHERMAL FIELD, NEVADA: IMPLICATIONS FROM HYDROTHERMAL ALTERATION AND STRATIGRAPHY  

Microsoft Academic Search

The main reservoir in the Dixie Valley geothermal field of Nevada is hosted in fractured Jurassic rocks within the hanging wall of the Stillwater fault. Within the Jurassic sequence, at least four major stages of alteration related to the fault system can be identified. The paragenetic sequence from oldest to youngest consists of Stage I) biotite-potassium feldspar veins, and epidote-chlorite-calcite

Susan J. Lutz; Joseph N. Moore; Dick Benoit

1997-01-01

28

Geologic Maps  

NSDL National Science Digital Library

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

Graymer, Russell

29

Geological images  

NSDL National Science Digital Library

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

Miller, Marli B.; Oregon, University O.

30

Archeological Geology  

ERIC Educational Resources Information Center

|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)|

Rapp, George

1977-01-01

31

Structural Geology  

NSDL National Science Digital Library

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

2009-05-21

32

Geology of five small Australian impact craters  

USGS Publications Warehouse

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

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

2005-01-01

33

Origin of convex tetrads in rare earth element patterns of hydrothermally altered siliceous igneous rocks from the Zinnwald Sn W deposit, Germany  

NASA Astrophysics Data System (ADS)

The chondrite-normalized rare earth element (REE) patterns of whole rock samples from evolved granitic systems hosting rare metal deposits sometimes show a split into four consecutive curved segments, referred to as tetrads. In the present contribution, a rigorous statistical method is proposed that can be used to test whether geological significance should be attributed to tetrads that are only of limited size. The method involves a detailed evaluation of element and sample specific random and systematic errors that are constrained on the basis of independent repeated preparations and analyses of sample and reference materials. Application of the proposed method to samples from the granite-hosted Zinnwald Sn-W deposit, Germany, revealed that at least two tetrads in normalized whole rock REE patterns have to be analytically significant to rule out that fractional crystallization led to the unusual behavior of the REEs. Based on the analysis of altered albite granite and greisen samples from the endocontact of the Zinnwald granite massif, it is demonstrated that the lanthanide tetrad effect is responsible for the formation of the convex tetrads. Geological and petrological evidence suggests that the tetrads in the samples developed prior to greisenization and related cassiterite precipitation. In contrast to the endocontact samples, the rhyolitic wall rocks are typified by normalized REE patterns having tetrads that are variable in size and frequently close to the limit of analytical significance. The sizes of the tetrads apparently correlate with the intensity of albitization, but show no relation to subsequent alteration processes including greisenization and low-temperature argillization. This observation proves that curved segments in normalized whole rock REE patterns can be introduced during hydrothermal fluid-rock interaction.

Monecke, T.; Dulski, P.; Kempe, U.

2007-01-01

34

Lunar geology  

NASA Astrophysics Data System (ADS)

The development of a lunar geological map is traced, from the post-war period through the final Apollo mission. The impact of geological discoveries on earth on lunar geology is explained, and the use of photographs of the lunar surface to deduce its stratigraphy is described. The confirmation of the ages of various parts of the moon's surface through analysis of moon rocks is also discussed.

Shoemaker, E.

35

California Geological Survey: Geologic Maps  

NSDL National Science Digital Library

This index provides access to a selection of geologic maps of California, as well as an overview of geologic and other mapping activities in the state. The index, which can be accessed by clicking on an interactive map of the state, contains lists of selected geologic maps in California prepared by the Regional Geologic Mapping Project (RGMP). The RGMP staff monitors the literature and collects references that contain geologic mapping that may be useful for future compilations. In addition, the site has information about Caltrans Highway Corridor Mapping, The Mineral Resources and Mineral Hazards Mapping Program, North Coast Watersheds Assessment Program, The Timber Harvesting Plan Enforcement Program, and The Seismic Hazards Mapping Program. A set of links is provided to other sources of geologic maps and map information.

36

North Cascades Geology: Geologic Time  

NSDL National Science Digital Library

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

37

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

USGS Publications Warehouse

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

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

2004-01-01

38

Yellowstone Geology  

NSDL National Science Digital Library

This Yellowstone National Park website provides geological information about the Park. Links include geologic highlights, hydrothermal features, reports by park geologists, and scientists' talks (videos). A wide array of information can be found on these links and the webpage is expanding as more topics are added.

Park, Yellowstone N.

39

Physical geology  

SciTech Connect

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

Skinner, B.; Porter, S.

1987-01-01

40

Engineering Geology  

ERIC Educational Resources Information Center

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

Hatheway, Allen W.

1978-01-01

41

Geologic Time  

NSDL National Science Digital Library

The Earth is very old -- 4.5 billion years or more -- according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.

Newman, William L.

1997-01-01

42

Geologic time  

USGS Publications Warehouse

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.

Newman, William L.

2000-01-01

43

Mathematical Geology.  

ERIC Educational Resources Information Center

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

McCammon, Richard B.

1979-01-01

44

Engineering Geology  

ERIC Educational Resources Information Center

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)

Lee, Fitzhugh T.

1974-01-01

45

Geologic Timeline  

NSDL National Science Digital Library

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

2000-01-01

46

Schoolyard Geology  

NSDL National Science Digital Library

This set of lessons provides teachers with ideas on how to turn their schoolyards into a rich geologic experience that students will find familiar, easily accessible, and personally relevant. The three lesson plans feature materials on mapping, rock descriptions and geologic interpretations, ages of rocks, and dinosaur tracks. Lesson 1, "Map Your Schoolyard," teaches students what maps are, what they are used for, and some features used on maps (north arrow, scale bar, legend, etc.). Lesson 2, "Rock Stories," illustrates how to make geologic observations and what important properties of rocks to look for. Lesson 3, "GeoSleuth Schoolyard," teaches students that geology is a lot like detective work, in which geologists infer the sequence and timing of events by collecting evidence and making observations. Relevant California state science standards are also listed.

47

Pennsylvania Geology  

NSDL National Science Digital Library

Three decades after it was published, the Second Geological Survey of Pennsylvania was described as "the most remarkable series of reports ever issued by any survey." Considering the diversity of other geological reports, this was no small compliment. Drawing on support from the Marion and Kenneth Pollock Libraries Program Fund, the Pennsylvania State University Libraries' Digital Preservation Unit was able to digitize not only this fabled Survey, but also the Third and Fourth Surveys as well. Visitors can use the search engine on the homepage to look for items of interest, or they can just browse through the collection at their leisure. The surveys include various maps and illustrations that track mineral deposits and the disposition and location of other natural resources. Additionally, users can look through a miscellaneous set of publications from the early 20th century related to survey work performed by the U.S. Geological Survey.

48

Teaching Geology  

NSDL National Science Digital Library

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

49

Geologic Explorations  

NSDL National Science Digital Library

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

Bodzin, Alec M.

2001-01-01

50

Geologic Time  

NSDL National Science Digital Library

This site contains 24 questions on the topic of geologic time, which covers dating techniques and unconformities. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate feedback.

Heaton, Timothy

51

Physical geology  

Microsoft Academic Search

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

B. Skinner; S. Porter

1987-01-01

52

Geologic Time.  

ERIC Educational Resources Information Center

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

Albritton, Claude C., Jr.

1984-01-01

53

Geologic nozzles  

Microsoft Academic Search

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

Susan Werner Kieffer

1989-01-01

54

Physical Geology  

NSDL National Science Digital Library

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

Nelson, Stephen

55

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

SciTech Connect

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.

Holt, R.M.; Powers, D.W. (IT Corporation (USA))

1990-12-01

56

Tour of Park Geology: Shoreline Geology  

NSDL National Science Digital Library

This National Park Service (NPS) site provides links to shoreline geology fieldnotes for National Parks, Monuments, and Recreation Areas. When appropriate, fieldnotes include visitor information, geology, maps, photographs, multimedia resources, geologic research, and teacher features (lessons for teaching geology with National Park examples). Some of the parks included on this site: Acadia National Park, Everglades National Park, and Padre Island National Seashore.

57

How does surface life affect interior geological processes?  

Microsoft Academic Search

How does surface life affect interior geological processes? We propose that biologically-mediated processes operating on the surface of the Earth need to be incorporated into our understanding of the geological evolution of the Earth. We argue that biotic effects may penetrate the lithosphere and be responsible for altering the dynamics of mantle convection. Geological processes have played a fundamental role

James Dyke; Fabian Gans; Axel Kleidon

2010-01-01

58

Vesta: A Geological Overview  

NASA Astrophysics Data System (ADS)

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.

Jaumann, R.

2012-04-01

59

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

USGS Publications Warehouse

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

Taylor, Cliff D.; Johnson, Craig A.

2010-01-01

60

Geological Time Scale  

NSDL National Science Digital Library

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

61

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

USGS Publications Warehouse

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

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

2004-01-01

62

Geology of Kilauea volcano  

SciTech Connect

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.

Moore, R.B. (Geological Survey, Denver, CO (United States). Federal Center); Trusdell, F.A. (Geological Survey, Hawaii National Park, HI (United States). Hawaiian Volcano Observatory)

1993-08-01

63

Geologic Frameworks and Faulty Hydrology  

NASA Astrophysics Data System (ADS)

Hydraulic properties frequently are distributed in groundwater flow and transport models with geologic frameworks that can be quite complex. The complexity of these frameworks increases exponentially as fault structures are explicitly incorporated. Creation of complex frameworks that support hydrologic investigations can be a reasonable endeavor where the hydraulic significance of geologic units and fault structures are substantiated with water-level and hydraulic property data. This underlying assumption seems highly suspect in practice because of differences in scale between water-level data and hydraulic data. Proposed connections between geology and hydraulic properties seem more tenuous when justified with scatter plots that resemble a line in a shot-gun blast. Weak correlations between hydraulic property estimates and geologic structures have been developed primarily with hydraulic property estimates from physical property measurements from cores and limited hydraulic tests. These hydraulic properties typically are estimated at length scales of less than 1 m and rarely exceeded 10 m. Water levels primarily are the hydraulic data that constrain groundwater-flow model calibration and typically are sampled at length scales of more than 1,000 m. Differences in length scales between weak correlations and hydraulic data are bridged with assumed geologic relations between development of secondary permeability and proximity to faults, rock type, and degree of alteration. The utility of geologic frameworks for extrapolating hydraulic properties at length scales that are commensurate with hydraulic data has been assessed at the Nevada National Security Site in highly faulted, volcanic rocks. Observed drawdowns from multiple aquifer tests provided necessary constraints. Bulk hydraulic properties in a volume of more than 40 cubic km were defined primarily by drawdowns that were detected across fault structures and more than 3 km from pumping wells. Hydraulic properties were estimated by simultaneously interpreting all aquifer tests. Each geologic framework was incorporated and tested as prior information that assumed homogeneity in each geologic structure. Hydraulic differences between geologic units and fault structures were less than the inherent uncertainty of the hydraulic conductivity estimates. Geologic frameworks that conceptualized fault structures as unique hydraulic features degraded extrapolation of hydraulic properties.

Halford, K. J.; Sweetkind, D. S.; Fenelon, J.; Garcia, C.

2011-12-01

64

History of Geology.  

ERIC Educational Resources Information Center

|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…

Greene, Mott T.

1985-01-01

65

Practical petroleum geology  

SciTech Connect

This book presents the scope and content of the field of petroleum geology from the standpoint of the practicing petroleum geologist. Includes chapters on basic geological concepts, the sedimentation process, accumulation of hydrocarbons, exploration, economic examination, drilling of exploratory wells, recovering oil and gas (reservoir geology), and the relationship of geology to the petroleum industry as a whole.

Not Available

1985-01-01

66

Co2 geological sequestration  

SciTech Connect

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.

Xu, Tianfu

2004-11-18

67

Tennessee Division of Geology  

NSDL National Science Digital Library

This is the homepage of the Geology Division of the Tennessee Department of Environment and Conservation. It provides information on the division's programs, including geologic hazards research, public service, education programs, basic and applied research on geology and mineral resources, publication of geologic information, permitting of oil and gas wells, and regulation of Tennessee's oil and gas industry. Materials include a catalog of publications, maps, geologic bulletins, and the Public Information series of pamphlets; the Geology Division Newsletter; and information on the state's mineral industry. There is also a section on the Gray Fossil Site, an unusual assemblage of fossils and sedimentary geology encountered during road construction near the town of Gray, Tenessee.

68

Oklahoma Geological Survey  

NSDL National Science Digital Library

The Oklahoma Geological Survey is a state agency dedicated to geological research and public service. This site contains information on earthquakes, geographic names, general Oklahoma geology, and the mountains and water resources of the state. There are educational materials available to order, many of which are free. Geologic maps indicate rock types and ages, as well as the geologic provinces of the state. Links are provided for more resources.

69

Vermont Geological Survey  

NSDL National Science Digital Library

The Vermont Geological Survey, also known as the Division of Geology and Mineral Resources in the Department of Environmental Conservation, conducts surveys and research relating to the geology, mineral resources and topography of the State. This site provides details about the states geology with a downloadable state geologic map and key, state rock information, gold in Vermont, fossils found in the state, bedrock mapping details, stream geomorphology, the Champlain thrust fault, earthquakes, radioactive waste and links for additional information.

70

Kentucky Geological Survey  

NSDL National Science Digital Library

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

1997-01-01

71

Geophysics & Geology Inspected.  

ERIC Educational Resources Information Center

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

Neale, E. R. W.

1981-01-01

72

GSA Geologic Time Scale  

NSDL National Science Digital Library

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

1999-01-01

73

Geologic Report for the Beaufort Sea Planning Area, Alaska: Regional Geology, Petroleum Geology, Environmental Geology.  

National Technical Information Service (NTIS)

The 192-page report provides a summary of the geologic framework, hydrocarbon potential, and physical environment of the offshore area tentatively scheduled for Federal OCS (Outer Continental Shelf) Oil and Gas Lease Sale 97. The geologic interpretation i...

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

1985-01-01

74

Geologic spatial analysis  

SciTech Connect

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

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

1989-01-01

75

Blueschist alteration during serpentinization  

Microsoft Academic Search

The petrogenesis of Franciscan-type blueschists is controversial or paradoxial in regard to the possible significance of the serpentinite-blueschist association, the isochemical vs. allochemical character of blueschist metamorphism, the significance of ``high pressure'' mineralogy, and the physical-geologic-tectonic conditions existing during metamorphism. A model for blueschist alteration during serpentinization is presented that departs from conventional treatments of metamorphism because the reaction path

Randall L. Gresens

1969-01-01

76

Louisiana Geological Survey  

NSDL National Science Digital Library

The Louisiana Geological Survey, located at Louisiana State University, developed this website to promote its goal to provide geological and environmental data that will allow for environmentally sound natural resource development and economic decisions. Users can find general information about the Survey's mission, staff, plan, and history. The website features the research and publications of the Basin Research, Cartographic, Coastal, Geologic Mapping, and Water and Environmental sections. Researchers can discover stratigraphic charts of Louisiana, information on lignite resources, and other geologic data.

77

South Carolina Geological Survey  

NSDL National Science Digital Library

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

78

Geological Survey Program  

NSDL National Science Digital Library

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

79

Analysis of Geological Structures  

Microsoft Academic Search

A knowledge of structural geology is fundamental to understanding the processes by which the earth's crust has evolved. It is a subject of fundamental importance to students of geology, experienced field geologists and academic researchers as well as to petroleum and mining engineers. In contrast to many structural textbooks which dwell upon geometrical descriptions of geological structures, this book emphasises

Neville J. Price; John W. Cosgrove

1990-01-01

80

Teaching Sedimentary Geology  

NSDL National Science Digital Library

This site contains a variety of resources for faculty members who teach undergraduate sedimentary geology. You will find links to a growing collection of activities and assignments, internet and computer resources, useful articles, presentations from the summer 2006 workshop on teaching sedimentary geology, and lots of creative ideas for teaching sedimentary geology.

81

Utah Geological Survey  

NSDL National Science Digital Library

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

2011-03-30

82

Geology of Kentucky  

NSDL National Science Digital Library

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

83

Virtual-Geology.Info  

NSDL National Science Digital Library

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

84

Ohio Geological Survey  

NSDL National Science Digital Library

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

85

Louisiana Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Louisiana Geological Survey (LGS). The site includes general information about LGS and its various offices, as well as an overview of the Basin Research Energy Section, the oil, gas, and coal research section of LGS. The publications and data page features a catalog and ordering information for documents on mineral resources, fossils, water resources, geological bulletins and maps, and many others, as well as a selection of downloadable maps, including 30 x 60 minute geologic quadrangles, a generalized geologic map of the state with accompanying text, and an online map viewer of the state with selectable layers (geology, water bodies, cultural features, and Landsat imagery). There is also an online listing of well logs, grouped by parish, online listings of core samples, grouped by state, and downloadable public information documents on a variety of geologic topics.

86

Geologic Time: Online Edition  

NSDL National Science Digital Library

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

1997-10-09

87

Image Gallery for Geology  

NSDL National Science Digital Library

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

Glazner, Allen

88

Sedimentology and petroleum geology  

SciTech Connect

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

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

1989-01-01

89

Pennsylvania Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Pennsylvania Geological Survey. Users can access digital maps, data, and Geographic Information Systems (GIS), information on economic resources, and information on field mapping in the state. Classroom resources include a set of lesson plans on Pennsylvania geology; 'Rock Boxes', a set of rock samples which can be ordered; information on mineral collecting; and a series of educational publications, page-sized maps, and the 'Trail of Geology' park guide.

2011-03-29

90

The Geology of Virginia  

NSDL National Science Digital Library

From the College of William of Mary Department of Geology comes the Geology of Virginia Web site. From the Appalachian Plateau to the coastal plain, visitors can explore the geology and physical characteristics of the diverse landscape of the commonwealth of Virginia through simple descriptions and well designed graphics. Even if you don't live in the area, the site does a good job of capturing the interest of anyone looking for quality material on the presented subjects.

1997-01-01

91

Practical petroleum geology  

SciTech Connect

This book contains the following eight chapters: Basic Concepts of Geology; Sedimentation; Oil and Gas Accumulation; Exploration; Economics; Well Sitting; Field Development; and Past, Present and Future. The goal of the book is to present a description of the field of petroleum geology that is centered on the point of view of the practicing petroleum geologist. After the beginning three chapters of pure geology, slanted toward the petroleum geologist's interest in oil and gas, the discussion turns toward more active concerns.

Leecraft, J.

1985-01-01

92

Icelandic Geology Resources  

NSDL National Science Digital Library

The main feature of this site from Hamrahlio College of Reykjavik, Iceland is an interactive geological map of Iceland showing lava flows and glaciers. Other highlights include links to related Icelandic geology pages (e.g., The Effect of Diatom Mining, Iceland's Ministry of the Environment), news sources and journals, and Icelandic geological societies (not all are in English). A recommended resource for glaciologists, volcanologists, and educators in earth science.

Douglas, Georg R.

93

Arizona Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Arizona Geological Survey. Information accessible here includes maps, information on oil, gas, and minerals in the state, back issues of the survey's newsletter, and a list of resources for public education in the state. These resources include information centers for Arizona geology and Earth Science, the survey's geology library and bibliographic database, a repository of rock cuttings and cores, and a contact for earth science education who will assist teacher groups in introducing local geology to their classes.

94

Understanding Geologic Maps  

NSDL National Science Digital Library

This is an exercise in which students are reintroduced to geologic maps and encouraged to "deconstruct" the map into constituent elements in order to understand the geologic history of the area. The preceding lectures in the course have recapitulated material that the students have covered in Introduction to Physical Geology. During class, the students work through the maps that were part of lab exercises in the Intro level course, so that basic concepts are recalled (superposition, cross-cutting relationships, basic faults and folds). The final product is a geologic history of this map area.

Burberry, Cara

95

Modeling Geologic Time  

NSDL National Science Digital Library

In this activity students convert major events in Earth history from years before present into scale distances. After a list of events and their scale distances have been formulated, students construct a geologic time scale on 5 meters of adding machine paper, beginning with the formation of the Earth. Students will investigate change through geologic time; design, construct and interpret a model of geologic time; relate major events in Earth history to the geologic time scale; and compare and relate the span of Earth history to events of historical time and of the human lifetime. Some sample events and their approximate relative ages are included.

Firebaugh, James

96

Geologic Mapping Exercise  

NSDL National Science Digital Library

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

Smith, Andrew

97

Geologic mapping of tectonic planets  

Microsoft Academic Search

Geological analysis of planets typically begins with the construction of a geologic map of the planets’ surfaces using remote data sets. Geologic maps provide the basis for interpretations of geologic histories, which in turn provide critical relations for understanding the range of processes that contributed to the evolution. Because geologic mapping should ultimately lead to the discovery of the types

Vicki L. Hansen

2000-01-01

98

The encyclopedia of applied geology  

Microsoft Academic Search

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.

Finkl

1984-01-01

99

Geology of California. Second Edition  

Microsoft Academic Search

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

R. M. Norris; R. W. Webb

1990-01-01

100

Earthquakes and Geology  

NSDL National Science Digital Library

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

Ozsvath, David

101

SOPAC marine geology atlases  

Microsoft Academic Search

The US Geological Survey conducted a series of marine geologic and geophysical cruises in the southwest Pacific Ocean in 1982 and 1984 as part of a program with participation by Australia and New Zealand. These two SOPAC expeditions obtained various data, which have been compiled into a series of charts and thematic products for the offshore areas of Tonga, Fiji,

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

1986-01-01

102

Geological hydrogen storage  

Microsoft Academic Search

The probably least expensive form of hydrogen storage would be geological storage in formations easy to excavate, such as salt dome intrusions near the surface (which can be excavated by water flushing) or vertically curved, capped aquifer layers not requiring excavation at all. Such geological formation are already in use for natural gas storage and have proven very stable. Consideration

Bent Sørensen

103

Earthquakes and Geology  

NSDL National Science Digital Library

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

Ozsvath, David

2011-09-06

104

People and Geology.  

ERIC Educational Resources Information Center

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

Naturescope, 1987

1987-01-01

105

Radiometric Dating in Geology.  

ERIC Educational Resources Information Center

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

Pankhurst, R. J.

1980-01-01

106

Radiometric Dating in Geology.  

ERIC Educational Resources Information Center

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

Pankhurst, R. J.

1980-01-01

107

Forensic geology exhumed  

Microsoft Academic Search

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

Joseph Didier Martinez

1991-01-01

108

Layer Cake Geology  

NSDL National Science Digital Library

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

Wagner, John

109

Structural Geology Techniques  

NSDL National Science Digital Library

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

Dutch, Steven

2009-05-21

110

California Geological Survey - Landslides  

NSDL National Science Digital Library

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

Survey, California G.

111

National Geologic Map Database  

NSDL National Science Digital Library

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

1997-01-01

112

Marine Geological Discoveries  

NSDL National Science Digital Library

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

113

People and Geology.  

ERIC Educational Resources Information Center

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

Naturescope, 1987

1987-01-01

114

LOMONOSOV AND MODERN GEOLOGY  

Microsoft Academic Search

The tribute to Mikhail V. Lomonosov on the occasion of his 250th anniversary of his birth enables better students of the history of geological science to identify the obvious confusion and glaring flaws in this overstated presentation of Lomonosov as the father of geology. Perhaps it will stimulate interest in Lomonosov's On Terrestrial Strata, published in 1763. The article contains

V. Ye Khain

1963-01-01

115

Wyoming State Geological Survey  

NSDL National Science Digital Library

This agency's mission is to study, examine, and seek an understanding of the geology, mineral resources, and physical features of the State; to prepare, publish, and distribute reports and maps of Wyoming's geology, mineral resources, and physical features; and to provide information, advice, and services related to the geology, mineral resources, and physical features of the State. This site contains details and reports about metals in Wyoming, earthquakes and other hazards, coal, industrial minerals, uranium, oil and gas. The field trip section contains details about various areas to visit with students and gives a general geologic description. There is also a searchable bibliography with publications about Wyoming geology. Links are provided for additional resources.

116

Essential Elements of Geologic Reports.  

ERIC Educational Resources Information Center

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

Webb, Elmer James

1988-01-01

117

Deterministic geologic processes and stochastic modeling  

SciTech Connect

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

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

1991-12-31

118

Indiana Geological Survey  

NSDL National Science Digital Library

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

119

Journal of Geology  

NSDL National Science Digital Library

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

120

Formation evaluation: Geological procedures  

SciTech Connect

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

Whittaker, A.

1985-01-01

121

What is Geologic Time?  

NSDL National Science Digital Library

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

122

Geology of caves  

USGS Publications Warehouse

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

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

1991-01-01

123

Web Geologic Time Scale  

NSDL National Science Digital Library

The University of California-Berkeley Museum of Paleontology (last mentioned in the June 16, 1995 Scout Report) has recently updated its Web Geologic Time Scale, an online feature that helps users learn about the geologic timeline and explore related museum exhibits. The familiar geologic timeline appears on the main page of the Web site, with hypertext links for each division of time. Every page of the Web Geologic Time Machine site is liberally sprinkled with links to related UCMP Web pages; think of it as a portal to all online information available from the museum. Altogether, this Web site provides a well-organized and comprehensive resource for learning how the planet has changed over time, and would be a great addition to earth or life sciences classroom material for a broad range of grades.

1994-01-01

124

Comprehending Geologic Time  

NSDL National Science Digital Library

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

125

Interactive Geologic Timeline Activity  

NSDL National Science Digital Library

In this learning activity, students use a web-based geologic timeline to examine temperature, CO2 concentration, and ice cover data to investigate how climate has changed during the last 715 million years.

University, Environmental L.

126

Geologic Puzzles: Morrison Formation  

NSDL National Science Digital Library

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

Macdonald, Heather

127

Economic Geology (Oil & Gas)  

ERIC Educational Resources Information Center

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

Geotimes, 1972

1972-01-01

128

Curating Geological Collections.  

National Technical Information Service (NTIS)

ONR funding was used to accomplish the long-term goals of the Scripps Institution of Oceanography Geological Collections, which have been and continue to be, to serve the scientific community by acquisition, maintenance, conservation and curation of marin...

J. W. Hawkins A. Sanfilippo

2004-01-01

129

Geology in the field  

SciTech Connect

This book is an entirely new one-volume text and reference that covers the procedures essential to geologic field studies. It presents information not found in other field geology texts, including identification and modern classification of rocks, means of recognizing and interpreting primary structures in rocks (which reveal their origin), coverage of engineering geologic maps, and recognition of recently active faults. The procedures are described thoroughly enough so that students can proceed largely on their own. It follows the typical sequence of a student's experience in learning field work-starting with the first observation of an outcrop and proceeding to methods of measurement and mapping, ending with preparation of a full geologic report.

Compton, R.R.

1985-01-01

130

Photos of structural geology  

NSDL National Science Digital Library

This page contains four categories of structural geology photos: brittle structures, ductile structures, active tectonics, and unconformities. All photos are freely downloadable and are at resolutions sufficient for power point.

Miller, Marli

131

North Dakota Geological Survey  

NSDL National Science Digital Library

This is the homepage of the North Dakota Geological Survey. Site materials include information on the state's oil, gas and coal resources, maps, publications, and regulations. The paleontology page features educational articles, information on fossil collecting, articles about fossil exhibits, and information on the state fossil collection. The state GIS hub creates and distributes digital spatial data that conforms to national mapping standards. The teaching tools page includes illustrations and descriptions of rocks and minerals found in the state, as well as information on meteorites and newsletter articles about teaching North Dakota geology. There are also links to landslide maps, surficial geology maps, and links to other survey publications such as reports, bulletins, field studies, other geological and topographic maps, and information on groundwater resources.

132

USGS Geologic Hazards  

NSDL National Science Digital Library

The Geologic Hazards section of the US Geological Survey (USGS) conducts research into the causes of geological phenomena such as landslides and earthquakes. The homepage connects visitors to the Geologic Hazards team's three main areas of endeavor. Geomagnetism provides links to the National Geomagnetic Information Center; Magnetic Observatories, Models, and Charts; and the Geomagnetic Information Node, which receives geomagnetic observatory data from around the world. The Landslide group studies the "causes and mechanisms of ground failure" to prevent "long-term losses and casualties." Their section provides links to the program and information center, publications, events, and current projects. The Earthquakes department hosts a wealth of information, including neotectonics, engineering seismology, and paleoseismology. Interactive maps are also provided.

133

External Resource: Geology Jeopardy  

NSDL National Science Digital Library

This interactive Geology Jeopardy game can by used by the individual to review concepts in earth science or in the classroom as a classroom activity. Topics: rocks, minerals, topography, plate tectonics, weathering, erosion, astronomy, meteorology.

1900-01-01

134

Geology and Human Health  

NSDL National Science Digital Library

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

135

Introduction to Petroleum Geology  

Microsoft Academic Search

\\u000a \\u000a Petroleum geology comprises those geological disciplines which are of greatest significance for the finding and recovery of oil and gas. Since\\u000a most of the obvious and “easy to find” petroleum already has been discovered it is necessary to use sophisticated methods\\u000a in the exploration of sedimentary basins. These include advanced geophysical techniques and basin modelling. There is also\\u000a much more

Knut Bjørlykke

136

Geology of Scotland  

Microsoft Academic Search

MAY I supplement Prof. Green's history of geological mapping in Scotland (NATURE, vol. xlvii. p. 49) by pointing out that Mr. Cruchley published, on March 23, 1840, ``A Geological Map of Scotland by Dr. MacCulloch, F.R.S., &c., published by order of the Lords of the Treasury by S. Arrowsmith, Hydrographer to the King.'' This fine map is on the scale

Grenville A. J. Cole

1892-01-01

137

Interpreting Geologic Sections  

NSDL National Science Digital Library

Athro, Limited is a for-profit corporation that publishes high school and college level biology, earth science, and geology course supplements and independent learning materials on the Web. This site provides instruction in interpreting the order of events in three hypothetical and one real geological section. For each section there is a list of events and an animation of the history of the section once the student has decided on the order of events.

Morris, Paul

138

Geological mapping of the moon  

NASA Astrophysics Data System (ADS)

A new 1:5,000,000 scale geological map of the moon has been compiled at the Geological Institute of the USSR Academy of Sciences. This paper gives a brief description of the legend of this map, and compares this map to previous geological maps compiled at the Geological Institute.

Sukhanov, A. L.

139

Visualization in Undergraduate Geology Courses  

Microsoft Academic Search

Visualization is an essential skill in undergraduate geology courses as it is for expert geologists. Geology students and geologists must visualize the shape of the land from topographic maps, the three-dimensional geometry of geologic structures from limited exposures, and the geologic history recorded in sequences of layers and in natural landscapes. Interactive animations have proven successful in helping college students

Stephen Reynolds; Julia Johnson; Michael Piburn; Debra Leedy; Joshua Coyan; Melanie Busch

140

Minnesota Geological Survey  

NSDL National Science Digital Library

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

2012-09-21

141

Geology of Io  

NASA Astrophysics Data System (ADS)

Geologic mapping of the Jovian satellite Io has been completed at 1:15,000,000 scale for an area lying between +40 and -90 deg latitude and 230 and 45 deg longitude, which includes portions of the Ruwa Patera quadrangle (Ji2) and the Lerna Region (Ji4) and the westernmost section of the Colchis Region (Ji3). Image resolution in the mapped area is commonly 0.5 to 2 km/pxl. High resolution areas (less than .5 km/pxl) are located near the south pole (Lerna Region) and in eastern Ruwa Patera quadrangle. Geologic maps for the Ruwa Patera quadrangle (Ji2) and the Lerna Region (Ji4) have been produced at 1:5,000,000 scale. The present effort reexamines the previously mapped areas and synthesizes the geology of Io on a global scale.

Greeley, R.; Craddock, R. A.; Crown, D. A.; Leshin, L. A.; Schaber, G. G.

1987-05-01

142

Geology for Everyone  

NSDL National Science Digital Library

This Geological Survey of Ireland website can increase the public's excitement about geology by offering simple, straightforward materials on the basics of geology. The website is divided into numerous themes such as Volcanoes, Rocks, Caves, and the Water Cycle. The links from each of the headings introduce the topic with simple descriptions and remarkable pictures and offer easy experiments when applicable. Students and educators can take virtual tours of the Ox Mountains, Killiney Beach, and other Irish landscapes. Everyone should visit the Landscapes for the Living link, which offers outstanding images of the diverse landscapes of Europe. While some of the themes are currently under construction, including Planet Earth, Plate Tectonics, and Earthquakes, the authors indicate that these materials will be added in the near future.

143

The geology of Ganymede  

NASA Astrophysics Data System (ADS)

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.

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

144

SOPAC marine geology atlases  

SciTech Connect

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

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

1986-07-01

145

Geology By Lightplane  

NSDL National Science Digital Library

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

Maher, Louis J.

2001-01-01

146

Sedimentology and petroleum geology  

SciTech Connect

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

Bjorlykke, K.

1989-01-01

147

Global sedimentary geology program  

SciTech Connect

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

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

1986-07-01

148

Project Primary Geology  

NSDL National Science Digital Library

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

Fryer, Karen

149

Principles of isotope geology  

Microsoft Academic Search

Discussions of methods of isotope dating using Rb-Sr, K-Ar, ⁴°Ar\\/³⁹Ar, Re-Os, Lu-Hf, K-Ca, U, Tb-Pb, ¹⁴C, common lead, S,O,H, fission track, and U-series disequilibrium are included in respective chapters. Introductory chapters discussing the basics of isotope geology, atomic structure, decay mechanisms and mass spectrometry are included along with two appendices; the geological time scale for the Phanerzoic and a fitting

G Faure

1977-01-01

150

Understanding Geological Time  

NSDL National Science Digital Library

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

151

Petroleum development geology  

SciTech Connect

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

Dickey, P.A.

1986-01-01

152

Yosemite in Depth: Geology  

NSDL National Science Digital Library

This reference provides detailed information and activities related to the geology of Yosemite National Park. The introduction provides a history of ideas on Yosemite's origin. An overview describes the geologic history of the Sierra Nevada Mountains. An interactive timeline is featured to provide users with a temporal reference on park history. For students, there is a field journal with interactive questions and exercises about the park, and a set of online activities that take place on the park's Mirror Lake Trail. Links to a glossary are embedded in the text, and a list of references is provided.

153

Life on Guam: Geology.  

ERIC Educational Resources Information Center

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…

Elkins, Gail

154

Geology of Wisconsin.  

ERIC Educational Resources Information Center

|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…

Madison Public Schools, WI.

155

Geologic controls on radon  

SciTech Connect

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

Gates, A.E.; Gundersen, L.C.S. (eds.)

1992-01-01

156

Geology of Callisto.  

National Technical Information Service (NTIS)

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 s...

P. M. Schenk

1995-01-01

157

Marine Geology and Geophysics  

NSDL National Science Digital Library

This National Oceanic and Atmospheric Administration website provides bathymetry, topography and relief data; digital coastlines; an interactive coastline extractor; ocean mapping; the geomorphology and bathymetry of the Great Lakes; geological data of the seafloor, and total sediment thickness; and geophysical data, including trackline measurements of gravity, and magnetics from global ocean areas.

158

Geology of Io.  

National Technical Information Service (NTIS)

Geologic mapping of the Jovian satellite Io has been completed at 1:15,000,000 scale for an area lying between +40 and -90 deg latitude and 230 and 45 deg longitude, which includes portions of the Ruwa Patera quadrangle (Ji2) and the Lerna Region (Ji4) an...

R. Greeley R. A. Craddock D. A. Crown L. A. Leshin G. G. Schaber

1987-01-01

159

Appendix E: Geology  

SciTech Connect

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.

Reidel, Steve; Chamness, Mickie A.

2008-01-17

160

Apollo's geology lesson  

NASA Astrophysics Data System (ADS)

An historical account of the Apollo Project's lunar rock samples are presented. The discovery of the rocks and the methods and equipment used in analyzing them are discussed. The results of the analysis of the lunar samples are briefly summarized with respect to lunar geology, evolution, and origin.

Goodman, Billy

1994-06-01

161

Geologic Structures Lab  

NSDL National Science Digital Library

Students learn about the variables governing the brittle and ductile behavior of rocks, the simple geological structures associated with differential stress, and look at and apply real data to evaluate the depth to the brittle-ductile transition in the crust and how that depth can change temporarily due to sudden changes in stress introduced by large earthquakes.

Leland, John

162

Geological and Inorganic Materials.  

ERIC Educational Resources Information Center

|Presents a review focusing on techniques and their application to the analysis of geological and inorganic materials that offer significant changes to research and routine work. Covers geostandards, spectroscopy, plasmas, microbeam techniques, synchrotron X-ray methods, nuclear activation methods, chromatography, and electroanalytical methods.…

Jackson, L. L.; And Others

1989-01-01

163

Geologic exploration of Mars  

Microsoft Academic Search

The scientific objectives and methods involved in a geologic exploration of Mars from a manned outpost are discussed. The constraints on outpost activities imposed by the limited crew size, limited amount of time available for science, the limited diversity of scientific expertise, and the competition between scientific disciplines are addressed. Three examples of possible outpost locations are examined: the Olympus

J. B. Plescia

1990-01-01

164

Glacial Geology of Wisconsin.  

ERIC Educational Resources Information Center

|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…

Madison Public Schools, WI.

165

Characterizing Lunar Crustal Geology  

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

166

Urban Geology (GEOL357)  

NSDL National Science Digital Library

This webpage describes the Urban Geology class at California State University - Los Angeles. The course explores the natural environment in and around urban population centers and looks at how planners can mitigate the effects of natural phenomena such as earthquakes, floods, and landslides.

California State University, L. A.

167

Principles of nuclear geology  

Microsoft Academic Search

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

Aswathanarayana

1985-01-01

168

Geology: The Active Earth.  

ERIC Educational Resources Information Center

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

Braus, Judy, Ed.

1987-01-01

169

Lyell's Geological Texts  

Microsoft Academic Search

RECENTLY, while referring to Charles Lyell' ``Elements of Geology'', it was found that the Yale Library copy, of date September 12, 1839, had been sent by the publishers to Benjamin Silliman. This was the first American edition from the first London edition as published by Kay Bros., Philadelphia, with 316 pages and 295 figures in the text. After one hundred

G. R. Wieland

1940-01-01

170

Elements of petroleum geology  

Microsoft Academic Search

This work surveys the modern science of petroleum geology. Its aim is twofold: to describe generation, migration, and entrapment of oil and gas, and to outline the various procedures used in their location, evaluation, and production. Selley begins the book with an account of the physical and chemical properties of petroleum, followed by a review of the methods of petroleum

Selley

1985-01-01

171

Geology of Crater Lake  

NSDL National Science Digital Library

The Geology of Crater Lake is a resource for an introductory course on the geology of Mount Mazama and the Crater Lake caldera. The actual course consists of two evening presentations and a one-day field trip. The presentations outline the mountain's geologic setting, eruptive history, and potential hazards. The field trip affords an opportunity to examine volcanic and glacial features around the caldera rim and to explore one of the most spectacular lakes in the world. Upon successful completion of this course a student will be capable of the following: to describe the geologic setting of Mount Mazama and the other Cascade volcanoes; to identify andesite, dacite, and basalt and explain how the compositions of the lavas that form these rocks influence their eruptive characters; and to outline the major types of hazards that future eruptions of Mount Mazama may pose to regional communities. Along with a course syllabus, a bibliography and related links are available. Those registered for the course can visit the Gradebook to view their marks.

Hirt, William

172

Soviet geology, 1976  

Microsoft Academic Search

The geological history of the Jurassic period shows that the most abrupt change in physiogeographical, and particularly in climatic, conditions occured not at its lower or upper limit but at the boundary between the middle and late epochs. This is shown especially clearly by a study of the lacustral and continental sediments which form such a significant feature of the

V. A. Vakhrameyev

1976-01-01

173

Geology of Mars  

NSDL National Science Digital Library

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

Hsui, Albert T.

2004-07-14

174

Geology en Espanol  

ERIC Educational Resources Information Center

|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)|

McGehee, Richard V.

1973-01-01

175

Geologic Map Database of Texas  

USGS Publications Warehouse

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.

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

2005-01-01

176

Using Snow to Teach Geology.  

ERIC Educational Resources Information Center

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

Roth, Charles

1991-01-01

177

Geology of the Colorado Plateau  

NSDL National Science Digital Library

This web page provides a general description of the geology of the Colorado Plateau. Topics include information about the various geologic environments and processes active during the Precambrian and the Paleozoic, Mesozoic and Cenozoic Eras.

Institute, Colorado P.

178

Geological Considerations for Lunar Telescopes.  

National Technical Information Service (NTIS)

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 te...

G. J. Taylor

1988-01-01

179

Ordering Geologic Events and Interpreting Geologic History: The Grand Canyon  

NSDL National Science Digital Library

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

Wenner, Jennifer

180

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...

2010-06-25

181

The Second Flowering of Geology.  

ERIC Educational Resources Information Center

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

Cloud, Preston

1983-01-01

182

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

Microsoft Academic Search

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

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

2011-01-01

183

Geologic Maps and Geologic Structures: A Texas Example  

NSDL National Science Digital Library

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

Steinberg, Roger

184

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

SciTech Connect

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

Landefeld, L.A.

1985-01-01

185

Elements of petroleum geology  

SciTech Connect

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

Selley, R.C.

1985-01-01

186

Oceanography - Marine Geological Processes  

NSDL National Science Digital Library

A first year course in oceanography with extensive Internet resources. Topics covered include: principles of thermodynamics, heat and mass transfer, fluid mechanics, continuum mechanics, and time-series analysis applied to marine geological and geophysical data; applications to transport of marine sediments; Pleistocene sedimentation and global climate change; and the thermal balance of the oceanic lithosphere. The link to the lecture schedule provides detailed supporting materials.

Mcduff, Russell

187

Greater Yellowstone Geology  

NSDL National Science Digital Library

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

Institute, Mountain P.; Infrastructure, National B.

188

Medical Geology in Africa  

Microsoft Academic Search

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

T. C. Davies

189

Geologic controls on radon  

Microsoft Academic Search

This text provides a review of recent research on geological controls of [sup 222]Rn concentrations in soil gas in relation to the problem of high indoor radon concentrations in houses. The importance of the subject matter is highlighted in the preface by the observation that the US Environmental Protection Agency (EPA) estimates that 15,000 to 25,000 deaths result from radon-induced

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

1992-01-01

190

Principles of nuclear geology  

SciTech Connect

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

Aswathanarayana, U.

1985-01-01

191

The Geology of Callisto  

NASA Astrophysics Data System (ADS)

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 mappable 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 begin to answer some fundamental questions when Callisto is observed by Galileo in late 1996.

Schenk, Paul M.

1995-09-01

192

Solute transport in fractured rocks with stagnant water zone and rock matrix composed of different geological layers—Model development and simulations  

NASA Astrophysics Data System (ADS)

A model is developed to describe solute transport and retention in fractured rocks. It accounts for the fact that solutes can not only diffuse directly from the flowing channel into the adjacent rock matrix composed of different geological layers but also at first diffuse into the stagnant water zone occupied in part of the fracture and then from there into the rock matrix adjacent to it. In spite of the complexities of the system, it is shown that the analytical solution to the Laplace-transformed concentration at the outlet of the flowing channel is a product of two exponential functions, and it can be easily extended to describe solute transport through channels in heterogeneous fractured media consisting of an arbitrary number of rock units with piecewise constant geological properties. More importantly, by numerical inversion of the Laplace-transformed solution, the simulations made in this study help to gain insights into the relative significance and the different contributions of the rock matrix and the stagnant water zone in retarding solute transport in fractured rocks. It is found that, in addition to the intact wall rock adjacent to the flowing channel, the stagnant water zone and the rock matrix adjacent to it may also lead to a considerable retardation of solute in cases with a narrow channel.

Mahmoudzadeh, Batoul; Liu, Longcheng; Moreno, Luis; Neretnieks, Ivars

2013-03-01

193

Kimberlite Wall Rock Fragmentation: Venetia K08 Pipe Development  

Microsoft Academic Search

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

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

2009-01-01

194

The Geologic Time Scale  

NSDL National Science Digital Library

This site contains a large, easy to read, detailed geologic time scale for the Phanerozoic Eon (544 million years ago - Present). This is the period of time, also known as an eon, between the end of the Precambrian and today. The Phanerozoic begins with the start of the Cambrian period, 544 million years ago. It encompasses the period of abundant, complex life on Earth. The chart includes the Era, Period or System, and the Epoch or Series and features a brief description of each.

195

Structural Geology and Geomechanics  

NSDL National Science Digital Library

The teaching and research program, Structural Geology and Geomechanics at Stanford University, concentrates on brittle deformation in the earth's crust as well as fracturing and faulting of rocks under ductile conditions. Researchers can learn about the group's research which effectively unites field observations, laboratory experiments, and theoretical modeling. Scientists can learn about the program's software such as the Poly3Dinv which uses triangular dislocations to solve linear inverse problems. The site also publicizes the Stanford Rock Fracture Project, which researches rock fractures, crustal deformation, and fluid flow.

196

Geological Survey of Tanzania  

NSDL National Science Digital Library

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

1997-01-01

197

Geology in North Dakota  

NSDL National Science Digital Library

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

198

British Geological Survey: Geomagnetism  

NSDL National Science Digital Library

The British Geological Survey illustrates its work monitoring the earth's magnetic field in the UK at this website. Users can learn about the six observatories located in the Atlantic and the UK. Using the Grid Magnetic Angle Calculator, visitors can determine the angle between the British National grid north and the magnetic north. The website features Mercator projects created with the World Magnetic Model, geomagnetic data for the academic community, space weather services for industry, and more. Students can find tutorials about the Earth's magnetic field, magnetic reversals, and magnetic storms.

199

Minnesota Geological Survey funded  

NASA Astrophysics Data System (ADS)

The Minnesota Geological Survey, which was in danger of being closed down due to lack of funding, recently had their $1,075 million budget restored for fiscal 1993. Governor Ann Carlson signed the new bill into law on January 17.“Enactment of this legislation has effectively removed the threat of closure that has hung over our heads since the veto on June 4, 1991,” according to MGS director Priscilla Grew. Carlson vetoed the line item of the 2-year University of Minnesota budget that funds the MGS. The MGS is funded under Minnesota's Higher Education bill, rather than as a state agency.

Bush, Susan

1992-03-01

200

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

NSDL National Science Digital Library

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

2004-05-01

201

Geologic Mapping of Mars  

NASA Astrophysics Data System (ADS)

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.

Price, Katherine H.

1998-05-01

202

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

203

Geologically current plate motions  

NASA Astrophysics Data System (ADS)

We describe best-fitting angular velocities and MORVEL, a new closure-enforced set of angular velocities for the geologically current motions of 25 tectonic plates that collectively occupy 97 per cent of Earth's surface. Seafloor spreading rates and fault azimuths are used to determine the motions of 19 plates bordered by mid-ocean ridges, including all the major plates. Six smaller plates with little or no connection to the mid-ocean ridges are linked to MORVEL with GPS station velocities and azimuthal data. By design, almost no kinematic information is exchanged between the geologically determined and geodetically constrained subsets of the global circuit-MORVEL thus averages motion over geological intervals for all the major plates. Plate geometry changes relative to NUVEL-1A include the incorporation of Nubia, Lwandle and Somalia plates for the former Africa plate, Capricorn, Australia and Macquarie plates for the former Australia plate, and Sur and South America plates for the former South America plate. MORVEL also includes Amur, Philippine Sea, Sundaland and Yangtze plates, making it more useful than NUVEL-1A for studies of deformation in Asia and the western Pacific. Seafloor spreading rates are estimated over the past 0.78 Myr for intermediate and fast spreading centres and since 3.16 Ma for slow and ultraslow spreading centres. Rates are adjusted downward by 0.6-2.6mmyr-1 to compensate for the several kilometre width of magnetic reversal zones. Nearly all the NUVEL-1A angular velocities differ significantly from the MORVEL angular velocities. The many new data, revised plate geometries, and correction for outward displacement thus significantly modify our knowledge of geologically current plate motions. MORVEL indicates significantly slower 0.78-Myr-average motion across the Nazca-Antarctic and Nazca-Pacific boundaries than does NUVEL-1A, consistent with a progressive slowdown in the eastward component of Nazca plate motion since 3.16 Ma. It also indicates that motions across the Caribbean-North America and Caribbean-South America plate boundaries are twice as fast as given by NUVEL-1A. Summed, least-squares differences between angular velocities estimated from GPS and those for MORVEL, NUVEL-1 and NUVEL-1A are, respectively, 260 per cent larger for NUVEL-1 and 50 per cent larger for NUVEL-1A than for MORVEL, suggesting that MORVEL more accurately describes historically current plate motions. Significant differences between geological and GPS estimates of Nazca plate motion and Arabia-Eurasia and India-Eurasia motion are reduced but not eliminated when using MORVEL instead of NUVEL-1A, possibly indicating that changes have occurred in those plate motions since 3.16 Ma. The MORVEL and GPS estimates of Pacific-North America plate motion in western North America differ by only 2.6 +/- 1.7mmyr-1, ~25 per cent smaller than for NUVEL-1A. The remaining difference for this plate pair, assuming there are no unrecognized systematic errors and no measurable change in Pacific-North America motion over the past 1-3 Myr, indicates deformation of one or more plates in the global circuit. Tests for closure of six three-plate circuits indicate that two, Pacific-Cocos-Nazca and Sur-Nubia-Antarctic, fail closure, with respective linear velocities of non-closure of 14 +/- 5 and 3 +/- 1mmyr-1 (95 per cent confidence limits) at their triple junctions. We conclude that the rigid plate approximation continues to be tremendously useful, but-absent any unrecognized systematic errors-the plates deform measurably, possibly by thermal contraction and wide plate boundaries with deformation rates near or beneath the level of noise in plate kinematic data.

DeMets, Charles; Gordon, Richard G.; Argus, Donald F.

2010-04-01

204

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

SciTech Connect

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

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

1985-12-01

205

Tour of Park Geology: Fossils  

NSDL National Science Digital Library

This National Park Service Geology site provides links to tours of individual National Parks, Monuments, and Recreation Areas that contain fossils. Where appropriate, for each park, links are provided to park geology, maps, photographs, geologic research, related links, visitor information, multimedia resources, and teacher features (resources for teaching geology with National Park examples). The list includes places such as the Grand Canyon, Dinosaur National Monument, Yellowstone, and Death Valley, along with less well-known areas such as the John Day Fossil Beds National Monument in Oregon.

206

Geologic processes influence the effects of mining on aquatic ecosystems  

USGS Publications Warehouse

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

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

2012-01-01

207

Geologic processes influence the effects of mining on aquatic ecosystems.  

PubMed

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. PMID:22645817

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

2012-04-01

208

Geologic map of Io  

USGS Publications Warehouse

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

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

2011-01-01

209

Acting Locally, Thinking Globally: One Geology?  

NASA Astrophysics Data System (ADS)

Geological survey organizations around the world are responsible for geological data for their own countries, but until recently those data had never been made accessible worldwide. This raised the question of whether we really do have a holistic understanding of the geology of our planet—one geology. OneGeology (http://www.onegeology.org) is a global venture created to increase the accessibility of geological map data and make them available on the Web. Geological survey organizations from 113 countries are currently participating in ¬OneGeology, and to date more than 40 of those organizations are serving geological data to a dedicated Web map portal (see Figure 1).

Jackson, Ian

2010-02-01

210

Geological consequences of superplumes  

SciTech Connect

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

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

1991-10-01

211

Geology in the News  

NSDL National Science Digital Library

For this activity students read the newspaper on a daily basis, listen to news on the radio, or watch television, to acquire material related to the earth sciences. They will look for natural hazards (earthquakes, volcanoes, landslides, hurricanes, etc.), human-made hazards (urbanization, compromised engineering projects, etc.), environmental issues, or resource extraction issues which all appear in the news with great frequency and are easily accessible. Students are reminded that they should look for information on the local level (water quality, solid waste management, development issues, etc.), as well as national and world wide issues. The news items may then be presented to the class as show-and-tell exercises with follow-up discussion by the class; a bulletin board that could be dedicated to posting the geologic events of the week; or scrapbooks of events, arranged either chronologically or by category of events compiled by individuals or classes.

Mogk, David

212

Geology of National Parks  

USGS Publications Warehouse

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

Stoffer, Philip W.

2008-01-01

213

Geologic mapping of Europa  

USGS Publications Warehouse

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

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

2000-01-01

214

Geologic mapping of Argyre Planitia  

NASA Astrophysics Data System (ADS)

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

Gorsline, Donn S.; Parker, Timothy J.

1995-03-01

215

Biologically Enhanced Geologic Carbon Sequestration  

Microsoft Academic Search

There are four trapping mechanisms proposed to play significant roles in the deep geologic sequestration of CO2: i) formation trapping, ii) capillary trapping, iii) solubility trapping, and iv) mineral trapping. Our research has shown that microbial biofilms are capable of enhancing formation trapping, solubility trapping, and mineral trapping under conditions found in brine aquifers targeted for geologic carbon sequestration. We

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

2010-01-01

216

The Geophysical Revolution in Geology.  

ERIC Educational Resources Information Center

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

Smith, Peter J.

1980-01-01

217

The Geophysical Revolution in Geology.  

ERIC Educational Resources Information Center

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

Smith, Peter J.

1980-01-01

218

The geology of the moon  

Microsoft Academic Search

With traditional astronomical methods in the background, geological exploration of the Moon has developed rapidly, but logically, since the dawn of the space age. Geological maps were prepared, fist, from Earth-based photographs of the Moon. They were improved when close-up pictures of the Moon were taken from spacecraft. Artificial satellites of the Moon were used as platforms on which to

G. Fielder

1973-01-01

219

Creationism, Uniformitarianism, Geology and Science.  

ERIC Educational Resources Information Center

|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)|

Shea, James H.

1983-01-01

220

Geology: Just Touching the Surface  

Microsoft Academic Search

In this unit, students will explore patterns of change in the earth's layers through hands-on experiments and activities, as well as case studies of geologic phenomena. Students will learn about volcano types, volcanic activity, and plate movement and its effects. Students will be exposed to the plate tectonic theory and its implications on geologic history. They will observe the effects

Michael Shay; Carrie Susong

2006-01-01

221

Surficial Geologic Map of Maine  

NSDL National Science Digital Library

In this activity students become familiar with the nature and use of the Surficial Geologic Map of Maine and gain practice in using maps other than topographic maps. They will discover that surficial geology deals primarily with the geologically youthful, unconsolidated sedimentary materials that exist at, or close to the surface of a specific area and are important because the surface deposits filter and control the access of water to the water table. Students also learn that the study of surficial geology is important for siting of waste disposal facilities and for resources such as sand, gravel, and clay. Although this activity was written for a map of Maine, it will work in any state where surficial geological maps are available.

222

Plutonium alteration phases from lanthanide borosilicate glass  

SciTech Connect

A prototype lanthanide borosilicate (LaBS) glass containing 10 mass % plutonium was reacted with water vapor at 200 C for periods of 14 to 56 days. These tests, while not designed to replicate specific conditions that may be found in a potential geologic repository (e.g., Yucca Mountain), have been shown to accelerate alteration phase formation. The surfaces of the glass samples, along with alteration phases, were examined with a transmission electron microscope (TEM). Tests of 14 days produced macroscopic ({approximately} 20 {micro}m) crystallites of a plutonium-lanthanide silicate. An extensive alteration layer was found on the glass surface containing amorphous aluminosilicate layered with bands of a cryptocrystalline plutonium silicate. After 56 days of testing, additional alteration phases were formed, including a strontium lanthanide oxide phase. One of the options for disposal of surplus plutonium, particularly for impure residues that may be unfit for production of MOX fuel, is vitrification followed by geologic disposal. Since geologic disposal requires a passive system to isolate the radiotoxic elements from the biosphere, it is important to understand the possible corrosion mechanisms of the waste form.

Fortner, J.A.; Mertz, C.J.; Chamberlain, D.C.; Bates, J.K.

1997-10-01

223

Geological-geotechnical studies for siting the superconducting super collider in Illinois: Preliminary geological feasibility report  

Microsoft Academic Search

Site suitability was determined from a geological perspective. A preliminary compilation of existing geologic maps, reports, and other readily available geologic data is reported. Maps and cross sections were prepared to focus on the geologic units relevant to ring siting; geologic units were described and characterized to a geologically and economically practical depth (about 600 ft (180 m)). The data

J. P. Kempton; R. C. Vaiden; D. R. Kolata; P. B. Dumontelle; M. M. Killey

1985-01-01

224

Geological Evolution of Lada Terra, Venus  

NASA Astrophysics Data System (ADS)

This paper presents geologic history of Lada Terra of Venus. Geological mapping revealed formation of large-scale extensional belts, coronae, and volcanogenic plains. The sequence of geologic events provides clues to deeper geodynamic processes.

Kumar, P. S.; Head, J. W.

2011-03-01

225

Geology of Earth's Moon  

NSDL National Science Digital Library

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

226

Multi- and hyperspectral geologic remote sensing: A review  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

227

Geology Fieldnotes: Grand Canyon National Park, Arizona  

NSDL National Science Digital Library

Visitors can access park geology information, photographs, related links, visitor information, multimedia resources, and resources for teaching geology with National Park examples. The park geology section discusses the Grand Canyon's geologic history, structural geology, and features a question-and-answer section about the canyon. The history of the canyon as a park and environmental issues surrounding it are also discussed. A geologic cross section of the canyon showing the various rock layers is included.

228

Proceedings of the international symposium on remote sensing of environment. Third thematic conference:Remote sensing for exploration geology  

SciTech Connect

This book presents the papers given at a conference on the remote sensing of petroleum and natural gas deposits. Topics considered at the conference included Landsat imagery, tectonics, a geologic database for petroleum exploration, lithology, hydrothermal alteration mapping, artificial intelligence, geothermal exploration, petroleum geology, geobotany, infrared spectral studies, carbonate rocks, radar, microcomputer-based digital image processing, and terrain mapping for exploration surveys.

Not Available

1984-01-01

229

Coyote Creek Geologic Map  

NSDL National Science Digital Library

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

Walsh, Timothy R.

230

Roadside Geology of Yosemite Valley  

NSDL National Science Digital Library

This field trip guide provides an introduction to the geology of Yosemite Valley, emphasizing the changes that have been made by a series of geological events and natural disasters in the 1990's. The field trip moves from Arch Rock Entrance station, via Bridalveil Meadow and Inspiration Point. It features background notes on glaciation, granitic and plutonic rock, and rockfall events. Users can also examine information on field debris, rock composition, granites, diorites, and sedimentary structures. Other materials include a geological map, images, and bibliographic references of interest. In addition, there are also computer generated images of some of the park's landforms.

231

Galapagos Geology on the Web  

NSDL National Science Digital Library

For those interested in natural history, there are few places quite as facinating as the Galapagos. The intention of this web site is to provide information on the Galapagos Islands to both scientists and non-scientists alike. While the emphasis of this web site is on geology, Galapagos wildlife is difficult to ignore, so you will find many images and observations on biology, as well as geology, on this site. Sections include: a brief introduction to Galapagos geology, Tour the Islands, Galapagos Climate and Oceanography, Galapagos History (which includes a discussion of Darwin's work related to evolution and natural selection), and a Bibliography.

232

National Archive of Geological Photographs  

NSDL National Science Digital Library

Provided by the British Geological Survey, this site contains a database of some 6,400 digitized images drawn from the National Archive of Geological Photographs (NAGP). The archive may be searched by keyword, advanced search, or browsed via themed galleries (Montserrat Volcanic Eruption, Beltmoss Quarry - working stone, Aerial photographs in and around Edinburgh, etc.). Unfortunately, the images are only available in one, rather small, size. They are accompanied by information on location, photographer, geologist, year taken, and descriptions of varying length. Additional information on the British Geological Survey may be accessed from the main page.

233

Osmotic generation of 'anomalous' fluid pressures in geological environments  

USGS Publications Warehouse

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

Neuzii, C. E.

2000-01-01

234

Northeastern Regional geologic characterization report. Volume 1. Final report  

SciTech Connect

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

Not Available

1985-08-01

235

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

SciTech Connect

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

Not Available

1985-08-01

236

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

237

Geologic history of Mars  

NASA Astrophysics Data System (ADS)

Mars accumulated and differentiated into crust, mantle and core within a few tens of millions of years of Solar System formation. Formation of Hellas, which has been adopted as the base of the Noachian period, is estimated to have occurred around 4.1 to 3.8 Gyr ago, depending on whether or not the planet experienced a late cataclysm. Little is known of the pre-Noachian period except that it was characterized by a magnetic field, subject to numerous large basin-forming impacts, probably including one that formed the global dichotomy. The Noachian period, which ended around 3.7 Gyr ago, was characterized by high rates of cratering, erosion, and valley formation. Most of Tharsis formed and surface conditions were at least episodically such as to cause widespread production of hydrous weathering products such as phyllosilicates. Extensive sulfate deposits accumulated late in the era. Average erosion rates, though high compared with later epochs, fell short of the lowest average terrestrial rates. The record suggests that warm, wet conditions necessary for fluvial activity were met only occasionally, such as might occur if caused by large impacts or volcanic eruptions. At the end of the Noachian, rates of impact, valley formation, weathering, and erosion all dropped precipitously but volcanism continued at a relatively high average rate throughout the Hesperian, resulting in the resurfacing of at least 30% of the planet. Large water floods formed episodically, possibly leaving behind large bodies of water. The canyons formed. The observations suggest the change at the end of the Noachian suppressed most aqueous activity at the surface other than large floods, and resulted in growth of a thick cryosphere. However, presence of discrete sulfate rich deposits, sulfate concentrations in soils, and occasional presence of Hesperian valley networks indicates that water activity did not decline to zero. After the end of the Hesperian around 3 Gyr ago the pace of geologic activity slowed further. The average rate of volcanism during the Amazonian was approximately a factor of ten lower than in the Hesperian and activity was confined largely to Tharsis and Elysium. The main era of water flooding was over, although small floods occurred episodically until geologically recent times. Canyon development was largely restricted to formation of large landslides. Erosion and weathering rates remained extremely low. The most distinctive characteristic of the Amazonian is formation of features that have been attributed to the presence, accumulation, and movement of ice. Included are the polar layered deposits, glacial deposits on volcanoes, ice-rich veneers at high latitudes, and a variety of landforms in the 30-55° latitude belts, including lobate debris aprons, lineated valley fill and concentric crater fill. Most of the gullies on steep slopes also formed late in this era. The rate of formation of the ice-related features and the gullies probably varied as changes in obliquity affected the ice stability relations.

Carr, Michael H.; Head, James W.

2010-06-01

238

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

239

Geologic Images Associated with Lectures  

NSDL National Science Digital Library

This site contains photographs of igneous rocks, sedimentary rocks (plus erosion & karst topography), faults, folding, metamorphism, and glaciation. Each photo can be viewed as the original photo or with annotations that describe the associated geology.

Hochstaedter, Alfred

240

Tethys geology and tectonics revisited  

NASA Astrophysics Data System (ADS)

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

Croft, Steven K.

1991-06-01

241

Geologic interpretation of gravity anomalies  

SciTech Connect

This Russian textbook provides a sufficiently complete and systematic illumination of physico-geologic and mathematical aspect of complex problem of interpretation of gravity anomalies. The rational methods of localization of anomalies are examined in detail. All methods of interpreting gravity anomalies are described which have found successful application in practice. Also given are ideas of some new methods of the interpretation of gravity anomalies, the prospects for further development and industrial testing. Numerous practical examples to interpretation are given. Partial Contents: Bases of gravitational field theory; Physico-geologic bases of gravitational prospecting; Principles of geologic interpretation of gravity anomalies; Conversions and calculations of anomalies; Interpretation of gravity anomalies for bodies of correct geometric form and for bodies of arbitrary form; Geologic interpretation of the results of regional gravitational photographing; Searches and prospecting of oil- and gas-bearing structures and of deposits of ore and nonmetalliferous useful minerals.

Andreyev, B.A.; Klushin, I.G.

1990-04-19

242

Perspectives in geology. Circular 525  

SciTech Connect

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

Not Available

1982-01-01

243

A Primer in Lunar Geology.  

National Technical Information Service (NTIS)

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.

P. H. Schultz R. Greeley

1974-01-01

244

Geology Programs and Disciplinary Accreditation.  

ERIC Educational Resources Information Center

Describes geology department attitudes toward accreditation. Most departments would not currently welcome accreditation. Those persons currently neutral or uncertain about disciplinary accreditation should learn more about it and take a firm position. (Author/SAH)

Corbett, Robert G.; Corbett, Erica A.

2001-01-01

245

Report on Geologic Exploration Activities.  

National Technical Information Service (NTIS)

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 provid...

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

1980-01-01

246

Central American geologic map project  

SciTech Connect

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

Dengo, G.

1986-07-01

247

Geological Surveys Bureau Browse Area  

NSDL National Science Digital Library

Offered by the Iowa Geological Survey Bureau, the Browse Area page is a great collection of articles, photos, and maps about the state's geology geared especially to the public. Topics include Age of Dinosaurs in Iowa, Landscape Features, Satellite Image, Field Travels of Early Iowa Geologists, Meteorites in Iowa's History, Oil Exploration, and much more. This is a wonderful example of how government can provide informative and fun sites to the public without going overboard with high-end and complicated Web design.

248

Engineering geology of Stockholm, Sweden  

Microsoft Academic Search

The bedrock in the Stockholm area provides an excellent material for construction. The paper describes the geology of the\\u000a area and provides case histories, mainly related to infrastructure development, illustrating the use of underground construction\\u000a and the importance given to environmental considerations. It discusses the research being undertaken to establish data bases\\u000a which will record the geological and geotechnical information

L. Persson

1998-01-01

249

Geology of the Cook Islands  

Microsoft Academic Search

The geology of the 15 Cook Islands in the south-central Pacific is briefly described and their geological history outlined. All are the summit portions of extinct Tertiary volcanoes; six of the seven Northern Group islands are atolls, four of the Southern Group are makatea-type islands, and the others include a high mountainous volcanic island, a hilly near-atoll, an atoll, and

B. L. Wood

1967-01-01

250

The Bureau of Economic Geology  

NSDL National Science Digital Library

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

251

Central American geologic map project  

Microsoft Academic Search

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,

Dengo

1986-01-01

252

Community Perceptions of Geologic Sequestration  

NASA Astrophysics Data System (ADS)

Political momentum for mitigating climate change through the use of large-scale energy technologies such as geologic sequestration is growing. This paper explores the views of communities living near an actual or potential geologic sequestration project site. Given the potential importance of geologic sequestration to U.S. energy policy, what might explain and influence the views of this technology by the community-members. Through focus groups and one-on-one interviews, we gathered the views of two communities in California's Central Valley. One community close to a Department of Energy sponsored geologic sequestration pilot-project and another similarly located community that is not actually a project site. Our analysis combined a review of the history of the communities with other technologies and their social and economic indicators with the results of the focus groups and interviews. The results suggest that the sense of community empowerment, as contextualized by the history of the community and socio-economic indicators, is an important indicator of positive views of geologic sequestration. In addition, the results indicate community members prefer to be informed about geologic sequestration from a variety of sources (e.g., academia and industry).

Wong-Parodi, G. M.; Farrell, A.; Ray, I.

2007-12-01

253

Geology Field Trips as Performance Evaluations  

ERIC Educational Resources Information Center

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…

Bentley, Callan

2009-01-01

254

Basic petroleum geology, 2nd ed. , revised  

Microsoft Academic Search

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,

Link

1990-01-01

255

Geology of the Spirit landing site in Gusev crater  

NASA Astrophysics Data System (ADS)

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

Golombek, M.; Athena Science Team

256

Geology Fieldnotes: Petrified Forest National Park, Arizona  

NSDL National Science Digital Library

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

257

Montana Bureau of Mines and Geology  

NSDL National Science Digital Library

The Montana Bureau of Mines and Geology is the principal source of earth science information for the citizens of Montana. The bureau provides extensive advisory, technical, and informational services on geologic, mineral, energy, and water resources in the state of Montana. This includes earthquake studies, environmental assessment, Geographic Information Services (GIS), geology and minerals, groundwater, mines information, coal, state mapping, and more. The publications database contains all Bureau publications as well as U.S. Geological Survey publications related to Montana geology.

258

Geology Fieldnotes: Guadalupe Mountains National Park, Texas  

NSDL National Science Digital Library

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

259

Illinois State Geological Survey: Teacher Resources for Geology  

NSDL National Science Digital Library

The Illinois State Geological Survey (ISGS) has worked hard to create this vast array of materials designed for teachers working in geology and the earth sciences. The site is divided into two primary areas: "ISGS Teacher Resources" and "Other Teacher Resources." The "Ask An Expert" section is a good place to start, and it contains an A to Z archive of questions (and answers) that have been posed so far. Visitors are welcome to explore topics here like isotope geochemistry, limestone petrography, and also "Gold in Illinois." Also, this area contains links to teaching geology, which are quite useful. The "Other Teacher Resources" area brings together links to germane sites, such as the Denver Earth Science Project, NASA's meteorology home page, and online guides to landforms from the U.S. Bureau of Land Management.

260

Recent geologic activity on Mercury  

NASA Astrophysics Data System (ADS)

Since the MESSENGER spacecraft was inserted into orbit about Mercury in March 2011, global and targeted high-resolution image data sets have been acquired. These images support the conclusion that internal geological activity on Mercury did not end early in planetary history, as had generally been previously thought, but continued to geologically recent times. Three lines of evidence point to recent geological activity on Mercury. (1) There are smooth plains with surface areas up to 1.5×105 km2 that postdate young (morphological class 1) craters, indicating probable Kuiperian-aged volcanism. No volcanic vents, fissures, or flow fronts have been identified on these plains, suggesting that they are products of low-viscosity lavas, consistent with komatiite-like compositions of large areas on Mercury indicated by MESSENGER X-Ray Spectrometer observations. (2) Young lobate scarps transect class 1 craters as large as 30 km in diameter, indicating comparably recent crustal contraction. (3) A number of fresh-appearing, high-reflectance, irregularly shaped and rimless shallow depressions interpreted as pyroclastic vents have few superposed craters, suggesting that they have been recently active. Growing evidence from geological and geochemical observations indicates that Mercury's interior contains a higher abundance of volatile materials than was previously appreciated. Together these findings support the inference that Mercury experienced relatively recent volcanism and tectonic deformation, and the possibility that the planet is geologically active today cannot be discounted.

Xiao, Z.; Strom, R. G.; Blewett, D. T.; Solomon, S. C.; Head, J. W.; Watters, T. R.; Chabot, N. L.; Banks, M. E.; Chapman, C. R.

2011-12-01

261

Geological steering of horizontal wells  

SciTech Connect

Horizontal well technology has evolved rapidly. The most difficult concerns have changed from borehole stability and drilling techniques to completion, stimulation, and formation evaluation. Tomorrow's challenge lies in steering the well path precisely by use of formation geologic and geophysical information. This geosteering technique is credited with major improvements in drilling results. One definition of geosteering is the planned interactive navigation of a wellbore using geological criteria. Geosteering implies feedback, with all available data continuously entered into the model of the well path and reservoir. Potential gains in production must be balanced with additional drilling and formation evaluation costs. Proper characterization requires knowledge of where the well path is located, where the current trajectory will take the well path, and where the wellbore should go. Uncertainty in geological modeling and the need to maximize profitability require an interdisciplinary team approach.

Meehan, D.N. (Union Pacific Resources Co., Fort Worth, TX (United States))

1994-10-01

262

Bedrock Geologic Map of Maine  

NSDL National Science Digital Library

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

263

Geology on a Sand Budget  

NSDL National Science Digital Library

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

Kane, Jacqueline

2004-09-01

264

Geology of the American Southwest  

NASA Astrophysics Data System (ADS)

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.

Baldridge, W. Scott

2004-06-01

265

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

USGS Publications Warehouse

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.

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

2002-01-01

266

Southeastern Regional geologic characterization report. Volume 1. Final report  

SciTech Connect

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

Not Available

1985-08-01

267

Geology 101 at University of Washington  

NSDL National Science Digital Library

Created by teaching assistant Gwyn Jones for students of Geology 101 at the University of Washington, Seattle, this Website offers good introductory geology lessons and study hints. Here, users will find lab and lecture notes, study questions and answers, and abundant links. Besides links to pages relevant to study topics, Jones's favorite geological sites are linked and also a comprehensive list of recommended books is given. Rocks, minerals, geologic time, geologic mapping, and natural hazards are the introductory topics featured. Students new to geology and instructors looking for ideas should visit this site. Please note that because the site is not updated regularly some links might not work.

Jones, Gwyneth.

1998-01-01

268

Effect of Hydrothermal Alteration on Rock Properties in Active Geothermal Setting  

NASA Astrophysics Data System (ADS)

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 200°C) 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.

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

2012-04-01

269

Energy storage in geologic media  

Microsoft Academic Search

This paper synthesizes current design concepts for the storage of potential energy in geologic media utilizing compressed air energy storage (CAES) and underground pumped hydro (UPH). These concepts have been refined through cooperative studies over the last 6 to 7 years by international utilities and by American utilities under the sponsorship of the Department of Energy (DOE) and the Electric

Gustin

1982-01-01

270

A Geologic Time Scale 2004  

Microsoft Academic Search

A successor to A Geologic Time Scale 1989 (Cambridge, 1990), this volume introduces the theory and methodology behind the construction of the new time scale, before presenting the scale itself in extensive detail. An international team of over forty stratigraphic experts develops the most up-to-date international stratigraphic framework for the Precambrian and Phanerozoic eras. A large wallchart summarizing the time

Felix M. Gradstein; James G. Ogg; Alan G. Smith

2005-01-01

271

The Concise Geologic Time Scale  

Microsoft Academic Search

This concise handbook presents a summary of Earth's history over the past 4.5 billion years as well as a brief overview of contemporaneous events on the Moon, Mars and Venus. The authors have been at the forefront of chronostratigraphic research and initiatives to create an international geologic time scale for many years, and the charts in this book present the

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

2008-01-01

272

INTERPLANETARY CORRELATION OF GEOLOGIC TIME  

Microsoft Academic Search

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

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

273

Geological Steering of Horizontal Wells  

Microsoft Academic Search

Horizontal well technology has evolved rapidly. The most difficult concerns have changed from borehole stability and drilling techniques to completion, stimulation, and formation evaluation. Tomorrow's challenge lies in steering the well path precisely by use of formation geologic and geophysical information. This geosteering technique is credited with major improvements in drilling results. One definition of geosteering is the planned interactive

D. Meehan

1994-01-01

274

Geology in coal resource utilization  

SciTech Connect

The 37 papers in this book were compiled with an overriding theme in mind: to provide the coal industry with a comprehensive source of information on how geology and geologic concepts can be applied to the many facets of coal resource location, extraction, and utilization. The chapters have been arranged to address the major coal geology subfields of Exploration and Reserve Definition, Reserve Estimation, Coalbed Methane, Underground Coal Gasification, Mining, Coal Quality Concerns, and Environmental Impacts, with papers distributed on the basis of their primary emphasis. To help guide one through the collection, the author has included prefaces at the beginning of each chapter. They are intended as a brief lead-in to the subject of the chapter and an acknowledgement of the papers' connections to the subject and contributions to the chapter. In addition, a brief cross-reference section has been included in each preface to help one find papers of interest in other chapters. The subfields of coal geology are intimately intertwined, and investigations in one area may impact problems in another area. Some subfields tend to blur at their edges, such as with reserve definition and reserve estimation. Papers have been processed separately for inclusion on the data base.

Peters, D.C. (ed.)

1991-01-01

275

Geologic exploration of solar system  

Microsoft Academic Search

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

Wood

1987-01-01

276

Recent Review Articles in Geology.  

National Technical Information Service (NTIS)

A list of review articles in the pages that follow is presented in part as an aid to geologists who are looking for specialized summaries, and in part as a sample of how much and what kind of review material is available in the current geological literatu...

H. E. Hawkes

1966-01-01

277

The complexity of simple geology  

NASA Astrophysics Data System (ADS)

Geology becomes, like all natural sciences, increasingly dependent on sophisticated, complex technologies. This is not generally acknowledged, because many geological 'products' seem so simple that it is, for both the general public and decision makers, often difficult to understand how complex the activities are that are needed for making these apparently very simple raw materials available. A good example is aggregate, probably the simplest geological product. The understanding of aggregate characteristics (required to determine whether the material is suited for a specific purpose) requires a profound knowledge of the rock properties and of the variation of these properties. This is not enough, however, since the users must also be convinced that 'stones' are not always interchangeable, but that the efficacy of their application depends on their characteristics. Particularly decision makers and customers in the fields of housing, civil engineering and environmental planning should be convinced that they need the expertise of earth-science specialists, and that they should have themselves at least a basic knowledge of applied geology, including the possible use of, and the problems related with, aggregate.

van Loon, A. J.

2002-11-01

278

ANNOTATED BIBLIOGRAPHY OF GEOLOGICAL EDUCATION.  

ERIC Educational Resources Information Center

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

BERG, J. ROBERT; AND OTHERS

279

Geology on a Sand Budget  

ERIC Educational Resources Information Center

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

Kane, Jacqueline

2004-01-01

280

GEOLOGY OF THE ANGARA REGION  

Microsoft Academic Search

Industrial development of the Angara region has necessitated geological exploration for available resources. The Angara River flows north from Lake Baikal, intersecting the mountains surrounding it; passes through the 'Irkutsk Amphitheater, ' part of the central Siberian platform; and, near Bratsk, flows across a diabase intrusion, forming the Bratsk rapids (approximately 300 kilometers long). The Angara river basin is underlain

M. M. Odintsov

1960-01-01

281

Geological-geotechnical studies for siting the Superconducting Super Collider in Illinois: preliminary geological feasibility report. Environmental geology notes  

Microsoft Academic Search

Although the use of the Tevatron as an injector for the SSC would save a significant amount of money, the suitability of the topography and geology of the Fermilab environs must be demonstrated. In June 1983, the Illinois State Geological Survey (ISGS) was asked to aid the Fermilab staff in determining site suitability from a geological perspective. It was agreed

J. P. Kempton; R. C. Vaiden; D. R. Kolata; P. B. DuMontelle; M. M. Killey

1985-01-01

282

Geology of the Jabal Riah area, Kingdom of Saudi Arabia  

USGS Publications Warehouse

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.

Wells, J. D.

1982-01-01

283

License for the Konrad Deep Geological Repository.  

National Technical Information Service (NTIS)

Deep geological disposal of long-lived radioactive waste is currently considered a major challenge. Until present, only three deep geological disposal facilities have worldwide been operated: the Asse experimental repository (1967-1978) and the Morsleben ...

E. Biurrun B. Hartje

2003-01-01

284

Geology Fieldnotes: Kobuk Valley National Park  

NSDL National Science Digital Library

This feature discusses the geology, landforms, glacial history, soils, and mineral resources of Kobuk Valley National Park. Links are provided to maps, visitor information, a history of gold prospecting in the area, and to related geology and conservation organizations.

285

Controversial Origin of Central Utah's Geologic Complexities.  

National Technical Information Service (NTIS)

Geology, a somewhat inexact science, differs from the more precise sciences such as chemistry and physics. In geology, many complex rock exposures are not readily decipherable, and consequently lend themselves to differing interpretations. Geologists have...

I. J. Witkind

1995-01-01

286

30 CFR 780.22 - Geologic information.  

Code of Federal Regulations, 2010 CFR

...minimum the following: (1) A description of the geology of the proposed permit and adjacent areas down...mining. The description shall include the areal and structural geology of the permit and adjacent areas, and other...

2009-07-01

287

30 CFR 780.22 - Geologic information.  

Code of Federal Regulations, 2010 CFR

...minimum the following: (1) A description of the geology of the proposed permit and adjacent areas down...mining. The description shall include the areal and structural geology of the permit and adjacent areas, and other...

2010-07-01

288

Extreme Events in the Geological Past  

Microsoft Academic Search

Many Xevents in the geological past exceeded the strengths and intensities observed for modern-day natural events. The number\\u000a of extraordinary events that occurred in the geological past is of course much larger than the number we witness today because\\u000a the geological timescale covers millions of years. This contribution focuses on these Xevents from earth’s geological history,\\u000a including selected examples from

Jürgen Herget

289

Geology Fieldnotes: Oregon Caves National Monument  

NSDL National Science Digital Library

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

290

Geology Fieldnotes: Timpanogos National Monument, Utah  

NSDL National Science Digital Library

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

291

Geological dictionaries—Critical elements of every geological database  

Microsoft Academic Search

British Geological Survey (BGS) staff have developed an extensive range of dictionaries to support database development both in-house and for other organisations. Four types of dictionary have been identified, namely unstructured, structured, sequential and multi-dimensional. The nature of, and problems associated with, these various types of dictionary are described and two examples of multi-dimensional dictionaries (Lithostratigraphical Lexicon and Chronostratigraphical Index)

J. R. A. Giles; D. J. Lowe; K. A. Bain

1997-01-01

292

Geological dictionaries—Critical elements of every geological database  

NASA Astrophysics Data System (ADS)

British Geological Survey (BGS) staff have developed an extensive range of dictionaries to support database development both in-house and for other organisations. Four types of dictionary have been identified, namely unstructured, structured, sequential and multi-dimensional. The nature of, and problems associated with, these various types of dictionary are described and two examples of multi-dimensional dictionaries (Lithostratigraphical Lexicon and Chronostratigraphical Index) are described in more detail.

Giles, J. R. A.; Lowe, D. J.; Bain, K. A.

1997-07-01

293

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

NASA Astrophysics Data System (ADS)

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.

Arvidson, R. E.

2011-12-01

294

The commensurability of environmental geology and petroleum geology  

SciTech Connect

Environmental geology and petroleum geology are practical applications of pure geology. These two applied sciences differ with respect to their philosophical and ethical mandates. A good petroleum geologist finds hydrocarbons, but the role of a good environmental geologist is not well defined. If the good environmental geologist's role is not simply to protect the environment from the good petroleum geologist then how do the mandates of these geologists differ, yet remain compatible If the mandate of a good environmental geologist were to protect every natural resource from all managed use, then the good environmental geologist and the good petroleum geologist would forever be at war. This mandate provides no framework for agreement because it assumes the inherent worth of each natural resource is discoverable. If the mandate of a good environmental geologist is to discover how to maximize the long-term benefits of the managed use of natural resource, then both the good environmental geologist and the good petroleum geologist would agree that no natural resource has inherent worth. The value of a natural resource is not determined by what it is, but by how it enhances the quality of life for a particular class of sentient creatures. An instrumental theory of value will provide a medium for interim disagreement on how to enhance the quality of life for sentient creatures, and also will provide the means for a long-term agreement that the managed use of natural resources enhances the long-term quality of life for sentient creatures.

Argen, R.J.

1990-05-01

295

Tour of Park Geology: Human Use Sites  

NSDL National Science Digital Library

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

296

Measuring student understanding of geological time  

Microsoft Academic Search

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

Jeff Dodick; Nir Orion

2003-01-01

297

Measuring Student Understanding of Geological Time  

ERIC Educational Resources Information Center

|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…

Dodick, Jeff; Orion, Nir

2003-01-01

298

Introduction to petroleum geology. Second edition  

Microsoft Academic Search

This petroleum geology text has been updated to cover the latest developments in structural geology and applied geophysics. This new revision of the second edition brings together a treatment of both the theoretical and the practical aspects of oil and gas geology, explaining the current techniques of geophysical exploration and subsurface reservoir delineation. The latest advances in computerized imaging from

G. D. Hobson; E. N. Tiratsoo

1985-01-01

299

Geology Fieldnotes: Cape Krusenstern National Monument, Alaska  

NSDL National Science Digital Library

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

300

Geology Fieldnotes: Great Basin National Park, Nevada  

NSDL National Science Digital Library

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

301

Mars geologic mapping program: Review and highlights  

Microsoft Academic Search

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

David H. Scott

1991-01-01

302

Physical Geology Notes and Visual Aids  

NSDL National Science Digital Library

This site contains notes, graphics, presentations and slides for a variety of physical geology topics, including geologic maps, volcanoes, mass-wasting, ground water, landforms, rock types, fossils and evolution, glaciers, geologic time, erosion, metamorphism, earthquakes, plate tectonics, and Earth resources.

Dutch, Steve

303

Thermal state and complex geology of a heterogeneous salty crust of Jupiter's satellite, Europa  

Microsoft Academic Search

The complex geology of Europa is evidenced by many tectonic and cryomagmatic resurfacing structures, some of which are “painted” into a more visible expression by exogenic alteration processes acting on the principal endogenic cryopetrology. The surface materials emplaced and affected by this activity are mainly composed of water ice in some areas, but in other places there are other minerals

Olga Prieto-Ballesteros; Jeffrey S. Kargel

2005-01-01

304

Geology of the reading prong  

SciTech Connect

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.

Schutz, D.

1987-03-01

305

Geological models of petroleum entrapment  

SciTech Connect

Assessing petroleum potential of a sedimentary basin requires an in depth knowledge of the relative timings of seven geological factors: source rock, hydrocarbon generation and maturation, primary migration, secondary migration, trap, reservoir rock, and cap or sealing rock. The main theme of this book is to estimate the relative timings of these events through simple geological modelling. The methods discussed in the book use graphs, charts and some simple mathematics. Assuming limited availability of data, Dr. Magara distinguishes static and dynamic elements and attempts to integrate evidence and inference fundamental to the practical exploration for oil and gas. His essential prediction is that even with limited data, or where, by definition, the record no longer exists, marginal predictive capability is superior to no prediction at all.

Magara, K.

1986-01-01

306

Geology of Badlands National Park  

NSDL National Science Digital Library

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

National Park Service (NPS)

307

Geologically constrained migration velocity analysis  

NASA Astrophysics Data System (ADS)

In areas of complex geology, prestack depth migration is the only way to produce an accurate image of the subsurface. Prestack depth migration requires an accurate interval velocity model. With few exceptions, the subsurface velocities are not known beforehand and must be estimated. When the velocity structure is complex, with significant lateral variations, reflection tomography methods must be applied. Unfortunately, reflection tomography often converges slowly, to a model that geologically unreasonable, or not at all. One reason for this slow or non-convergence is that reflection tomography attempts to simultaneously estimate reflector position (mapping velocity) and image the data (focusing velocity). In this dissertation, I present a new approach to finding an acceptable interval velocity model for prestack migration. By performing tomography in vertical travel-time space, I avoid estimating mapping velocity, instead concentrating on focusing velocity. The large null space of reflection tomography problems forces a sparse parameterization of the model and/or regularization criteria to be added to the estimation. Standard tomography schemes tend to create isotropic features in velocity that are inconsistent with geology. These isotropic features are due in large part to using symmetric regularization operators or by choosing a poor model parameterization. By replacing these symmetric operators with operators that tend to spread information along structural dips, I can generate velocity models that are more geologically reasonable. In addition, by forming these operators in helical 1-D space and performing polynomial division, I can find the inverse of these space-varying anisotropic operators. These inverse operators can be used as a preconditioner to a standard tomography problem, significantly improving convergence speed compared to the typical, regularized inversion problem. Results from synthetic, 2-D field, and 3-D field data are shown. In each case the velocity obtained improves the focusing of the migrated image.

Clapp, Robert G.

308

Perkins Geology Museum Digital Archive  

NSDL National Science Digital Library

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

309

Geological mapping in West Virginia  

SciTech Connect

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

Dean, S.L. (Univ. of Toledo, Toledo, OH (United States). Dept. of Geology); Kulander, B.R. (Wright State Univ., Dayton, OH (United States). Dept. of Geological Sciences); Lessing, P. (West Virginia Geological Survey, Morgantown, WV (United States))

1992-01-01

310

Radioactive waste disposal and geology  

Microsoft Academic Search

This book is an excellent, well-presented treatise on the nature and types of radioactive wastes, disposal alternatives and strategies, radionuclide release and disposal models, geologic repositories, natural analogues, subsea-bed options, and low-level wastes. The authors provide national and international perspectives on radioactive waste disposal problems. They carefully dissected each issue, treating its pros and cons equally. Moreover, they is careful

K. B. Krauskopf

1988-01-01

311

Marine Geology: Research Beneath the Sea  

NSDL National Science Digital Library

Another informative offering from the US Geological Survey is the Marine Geology: Research Beneath the Sea Web site. Visitors can read about the agency's Marine Geology program which "strives to increase our understanding of the geology of the lands covered by water." Topics include methods and equipment used for the research, plate tectonics, resources in the marine realm, predicting effects of marine processes, new frontiers, and even images of marine geology. This interesting and unique site does a good job of explaining and educating the public on this important segment of the agency's research.

312

Pennsylvania's contribution to petroleum geology  

SciTech Connect

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.

Dickey, P.A.

1989-09-01

313

Alteration of Impact Melts  

NASA Astrophysics Data System (ADS)

In this project we study the alteration processes of melt rocks, impact melt in particular. Experimental analyses, succeeded by mineralogical and geochemical modeling, explain the formation of alterations products, e.g., smectites, saponite, zeolites.

Dypvik, H.; Hellevang, H.; Kalleson, E.

2012-03-01

314

Preliminary Geologic Characterization of West Coast States for Geologic Sequestration  

SciTech Connect

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).

Larry Myer

2005-09-29

315

Leaching and Attenuation Characteristics of Unaltered and Thermally Altered Materials from the Rocky Mountain 1 Underground Coal Gasification Field Site.  

National Technical Information Service (NTIS)

This report reviews the results of an experimental leaching and attenuation investigation involving unaltered and thermally altered geological materials from the Rocky Mountain 1 (RM1) underground coal gasification (UCG) field test site near Hanna, Wyomin...

D. J. Hassett D. F. Pflughoeft-Hassett C. R. Schmit

1998-01-01

316

Geologic setting, genesis and transformation of sulfide deposits in the northern part of Khetri copper belt, Rajasthan, India — an outline  

NASA Astrophysics Data System (ADS)

The present study is confined to the northern part of the Khetri copper belt that extends for about 100 km in northern Rajasthan. Mineralization is more or less strata-bound and is confined to the garnetiferous chlorite schist and banded amphibolite quartzite, occurring towards the middle of the Proterozoic Delhi Supergroup. Preserved sedimentary features and re-estimation of the composition of the pre-metamorphic rocks suggest that the latter were deposited in shallow marine environment characterized by tidal activity. Cordierite-orthoamphibole-cummingtonite rock occurring in the neighbourhood of the ores is discussed, and is suggested to be isochemically metamorphosed sediment. The rocks together with the ores were deformed in two phases and metamorphosed in two progressive and one retrogressive events of metamorphism. Study of the host rocks suggests that the maximum temperature and pressure attained during metamorphism are respectively 550 600°C and < 5.5 kb. Principal ore minerals in Madan Kudan are chalcopyrite, pyrrhotite, pyrite and locally magnetite. In Kolihan these are chalcophyrite, pyrrhotite and cubanite. Subordinate phases are sphalerite, ilmenite, arsenopyrite, mackinawite, molybdenite, cobaltite and pentlandite. The last two are very rare. Gangue minerals comprise quartz, chlorite, garnet, amphiboles, biotite, scapolite, plagioclase and graphite. The ores are metamorphosed at temperatures > 491°C. Sulfide assemblages are explained in terms of fS 2 during metamorphism. Co-folding of the ore zone with the host rocks, confinement of the ores to the carbonaceous pelites or semi-pelitic rocks, strata-bound and locally even stratiform nature of the orebodies, lack of finite ‘wall rock alteration’, metamorphism of the ores in the thermal range similar to that for the host rocks, absence of spatial and temporal relationship with the granitic rocks of the region led the authors to conclude that the entire mineralization was originally sedimentary-diagenetic. Any loss of primitive features and development of incongruency are due to subsequent deformation and metamorphism to which the ores and their hosts were together subjected.

Sarkar, S. C.; Dasgupta, Somnath

1980-07-01

317

GeoSciML version 3: A GML application for geologic information  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

318

Geodetic Modeling With Realistic Geology  

NASA Astrophysics Data System (ADS)

Crustal structure has significant impact on the gravity field in short to intermediate wavelengths and lateral variations in density at or near the surface also affect the field. The U.S. Naval Research Laboratory will begin in FY2010 a research program to develop advanced geodetic modeling techniques utilizing realistic geologic and geophysical constraints to improve gravity anomaly estimation in mountainous terrains. The effort is facilitated by several new high-altitude airborne gravity data sets that will provide ground truth for modeling in several different geologic environments. Data sets collected over the Himalayas, the Alps and the mountains of Taiwan will be used to develop, calibrate and test regional models having different geologic conditions including crustal thickness and flexural rigidity, average regional sediment thickness, fault geometry, geomorphology and local density variations. Medium wavelength satellite gravity such as the Gravity Recovery and Climate Experiment (GRACE) data will allow comparison with the upward continued models as a check on the accuracy of the estimates and can also be used to estimate longer wavelength components due to the crust-mantle interface from either remove-restore methods of modeling or from two dimensional loaded plate theory under appropriate assumptions of flexural rigidity. Buried basement topography masked by sediments is a primary contributor to unknown short wavelength features and will be of great importance in stream-cut mountain valleys and depositional plains adjacent to exposed mountain ridges: we will use existing data sets to test the effects of various basement morphologies. Our modeling strategies will be tested for biases in medium and short wavelength components against existing ground truth, airborne and satellite data sets. Some of the proposed modeling has been previously done for specific and limited areas but we propose to examine to what extent it is possible to determine regional parameterizations that can be used to forward model large areas.

Brozena, J. M.; Peters, M. F.; Jung, W.

2009-05-01

319

Petroleum geology of southwestern Ohio  

SciTech Connect

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.

Sitler, G.

1987-09-01

320

Connecting Soils and Glacial Geology  

NSDL National Science Digital Library

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

Dolliver, Holly

321

Observations and Measurements in Geology  

NSDL National Science Digital Library

This activity allows students to see several key geologic concepts that they will learn in greater detail later in the semester. They compare densities of two different blocks, which serve as proxies for the differences between oceanic and continental crust, and this provides an example of isostasy. They determine sedimentation rates and deduce what type of changes in environment can affect these rates. They determine the relative ages of two different Martian surfaces. Students also get to see hand samples of rock and mineral specimens, and compare hardness and relative sorting. These topics allow students exposure to several different concepts that they will develop a greater appreciation of throughout their courses.

Cochiara, Stacey

322

United States Geological Survey yearbook  

SciTech Connect

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.

Not Available

1988-01-01

323

Geologic Sequestration Studies with Hawaiian Picrites  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

324

Geology and geochemistry of radon in shear zones  

SciTech Connect

The objective of this project is to understand the geologic control on distribution and availability of radon gas in areas where sheared fault zones cause localized, anomalously high concentrations of radon in rocks, soils, and water. Sheared fault zones in bedrock have been identified as the cause of some of the highest indoor radon and water borne radon problems recorded in the United States (Boyertown, Pennsylvania and Clinton, New Jersey are well known examples). This study will provide detailed geological and geochemical models of the processes that create very high concentrations of radon in shear zones. The main research goals are to: (1) characterize and quantify uranium enrichment in shear zones by examining the chemical and deformational processes involved; (2) develop predictive models that will identify severe radon occurrences by rock type, amount of deformation (including shear strain), deformational style, and amount of radionuclide enrichment and chemical alteration; (3) characterize and quantify the effect of the deformation fabric of the rock on soil development, permeability, radon migration and emanation, alteration, and radium distribution; and (4) characteize and quantify the rock-water equilibria within shear zones that produce the extreme concentrations of radon in water derived from sheared rock aquifers, and examine the contribution of radon in water to indoor radon concentrations. 23 refs.

Gundersen, L.C.S. (Geological Survey, Reston, VA (USA)); Gates, A.E. (Rutgers--the State Univ., Newark, NJ (USA). Dept. of Geology); Wanty, R.B. (Geological Survey, Denver, CO (USA)); Schultz, A.P. (Geological Survey, Reston, VA (USA))

1990-01-01

325

Maine Geological Survey: Online Educational Materials  

NSDL National Science Digital Library

The Maine Geological Survey (MGS) has crafted a fine set of materials for those interested in learning more about the state's natural history via virtual tours, lesson plans, and maps. First up is the Virtual Tour of Maine Geology, which includes photographs of bedrock geology, geologic hazards, mineral collecting, and surficial geology. The Lesson Plans area contains 51 lessons, including "Igneous Rock Identification" and "Composition of Topsoil." A number of MGS maps are available online in the Maps and Publications area. The site includes a Bibliography of Maine Geology, which contains over 12,000 references. Additionally, the site contains a link to the MGS publications page, which has official state of Maine wall maps available for purchase.

2009-12-08

326

Geologic Provinces of the United States  

NSDL National Science Digital Library

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

Leech, Mary

327

National Park Service: Tour of Park Geology  

NSDL National Science Digital Library

The tour of Park geologic resources includes pages specific to individual National Parks, Monuments, Recreation Areas, Preserves, Seacoasts, Reserves, and Recreation Areas. These pages are indexed by park name, state, or by one of the following topics: basin and range, caves, Colorado Plateau, fossils, glaciers, hot springs, human use, mountain building, oldest rocks, plate tectonics, river systems, sand dunes, shoreline geology, or volcanoes. Organization of each of the pages typically follows a NPS template with categories for park geology, maps, photographs, geologic research, related links, visitor information, multimedia, and "teacher features" (educational resources and links for teaching geology with National Park examples.) Common subjects that are addressed at various park sites include: minerals, rocks, fossils, cave and karst systems, coastlines, glaciers, volcanoes, faults, landforms, landslides, structures, fluvial systems, sediments, soils, stratigraphic relations, processes that form or act on geologic features and their chemical compositions, and the history of the planet and its life forms.

328

Global Geological Mapping of Enceladus  

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

329

Teaching Resources in Structural Geology  

NSDL National Science Digital Library

To some, the terms folds, faults, and shear zones might suggest a type of elaborate and cutting-edge style of origami. Those in the know will think immediately of the field of structural geology, and this site is a fine resource for information within that area of geology. Rob Butler, Martin Casey, Geoff Lloyd, and Andrew McCaig, all of whom work in the School of Earth Sciences at the University of Leeds, created these teaching resources. Visitors can start their journey through the site by clicking on the "Basic Principles" section, which contains a nice overview of the patterns of rock organization and how geologists understand the history of rock patterns. The other sections of the site provide basic overviews of shear zones, fault patterns, minor structures, and strain. The site is rounded out by a few virtual field trips, which will be quite helpful for those who can't make it to the Himalayas or the fabled Western Gneiss region of Norway.

Butler, Rob; Casey, Martin; Lloyd, Geoff; Mccaig, Andrew

330

County digital geologic mapping. Final report  

SciTech Connect

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

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

1995-12-31

331

The Geologic History of Cape Cod, Massachusetts  

NSDL National Science Digital Library

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

Oldale, Robert

332

Geology Fieldnotes: Capitol Reef National Park, Utah  

NSDL National Science Digital Library

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

333

Learning Assessment #5 - Geologic Time (2011)  

NSDL National Science Digital Library

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

Reid, Leslie; Speta, Michelle

334

Geology Fieldnotes: Badlands National Park, South Dakota  

NSDL National Science Digital Library

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

335

Geology Fieldnotes: Dinosaur National Monument, Colorado / Utah  

NSDL National Science Digital Library

Dinosaur National Monument preserves a fossil bone deposit containing the bones of hundreds of dinosaurs, which was once enclosed in the sands of an ancient river. Features of the site include park geology information, maps, photographs, related links, visitor information, multimedia resources, and resources for teaching geology with National Park examples. The geology section discusses the park's geologic history and fossil beds. A park map of the Monument is included, and the photo album section contains drawings of some of the dinosaur species found at the Monument's Dinosaur Quarry.

336

Geology Fieldnotes: Fossil Butte National Monument, Wyoming  

NSDL National Science Digital Library

Fossil Butte National Monument preserves a 50-million year old bed of Eocene limestone that contains one of the richest fossil deposits in the world. Site features include park geology information, photographs of fossils, related links, visitor information, multimedia resources, and resources for teaching geology with National Park examples. The park geology section discusses the Monument's geologic history and fossil beds, focusing on the conditions that created the fossil-rich region and on the history of fossil collection in the area. A map of the Monument is also included.

337

Europa: Divining Water from Surface Geology  

NASA Astrophysics Data System (ADS)

Europa's surface geology as viewed by Galileo imaging suggests a thin brittle lithosphere above a warm (potentially salt-rich) ice layer that is at least in part convecting, in turn situated above a liquid water ocean. This configuration is consistent with thermal and geochemical modeling, and with Galileo magnetometer and NIMS results, which suggest that Europa may have a salty global-scale subsurface ocean at relatively shallow depths (~20-30 km). Dynamical modeling and visible crater density suggests a surface age of ~50 million years, implying that Europa is probably still geologically active today. Large shallow craters and even larger multi-ringed structures imply impact into low-viscosity (warm) subsurface material. The satellite's bright plains are criss-crossed by narrow troughs and enigmatic double ridges (paired ridges separated by a medial trough); a morphological sequence (and implied evolutionary sequence) exists from isolated troughs to doublet ridges to wider and more complex ridge morphologies. Troughs are inferred as widened fractures formed though tensile and shear failure in response to global stressing of the ice shell above liquid water. Several models exist to explain ridges, but the most likely is one in which localized shear heating triggers upwelling of warm ice along fracture zones. Triple bands are ridges with diffuse ruddy margins that may have formed through thermal alteration and/or partial melting of briny ice. Wider pull-apart bands represent complete separation and spreading of the icy lithosphere, in a manner broadly analogous to terrestrial sea-floor spreading. Europa's global lineament pattern implies that nonsynchronous rotation and orbital flexing ("diurnal" stressing) have worked in tandem to deform the surface. Diurnal stressing can explain Europa's extremely enigmatic cycloid ridge and fracture patterns, and may drive rapid strike-slip faulting along ridges. Because significant tidal amplitude is necessary to produce significant diurnal stressing, this argues strongly for a subsurface liquid layer, but does not constrain its depth. Extremely slow nonsynchronous rotation of the ice shell may drive shear failure in equatorial regions, and may have opened the satellite's pull-apart bands. Mottled terrain consists of pits, domes, dark spots, patches of smooth plains, and regions of chaos terrain. Chaos is characterized by fragmented blocks of the preexisting surface, some of which have translated a few kilometers from their original positions, in a dark hummocky matrix. Mottled terrain landforms suggest vertical deformation and disruption of the surface along with localized partial melting. Their formation has been interpreted as due to diapiric upwelling--the expression of solid-state convection of warm subsurface ice--predicted to occur within an ice shell tens of kilometers thick above liquid water. Warm ice diapirs can circulate material between Europa's ocean and shallow levels within the ice shell, and can trigger local partial melting of briny ice, potentially creating near-surface biological niches. Europa's astonishing geology and its biological potential makes the satellite a high priority for future orbital and landed exploration.

Pappalardo, R. T.

2001-12-01

338

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

NSDL National Science Digital Library

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

339

Geologic Studies in Alaska by the U.S. Geological Survey, 1999.  

National Technical Information Service (NTIS)

The collection of nine papers that follow continue the series of U.S. Geological Survey (USGS) investigative reports in Alaska under the broad umbrella of the geologic sciences. Contents: Redoubt Volcano and the Alaska Volcano Observatory, 10 years later;...

L. P. Gough F. H. Wilson

2001-01-01

340

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

Federal Register 2010, 2011, 2012, 2013

...m. Mountain Standard Time. The Advisory Committee...and implementation of the geologic mapping and data preservation...m. Mountain Standard Time. FOR FURTHER INFORMATION...the National Cooperative Geologic Mapping Program and...

2013-09-20

341

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

Federal Register 2010, 2011, 2012, 2013

...m. Eastern Standard Time. The Advisory Committee...and implementation of the geologic mapping and data preservation...m. Eastern Standard Time. FOR FURTHER INFORMATION...the National Cooperative Geologic Mapping Program and...

2012-06-27

342

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

USGS Publications Warehouse

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

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

1972-01-01

343

Geologic Studies of the Platte River, South-Central Nebraska and Adjacent Areas: Geologic Maps, Subsurface Study, and Geologic History.  

National Technical Information Service (NTIS)

The Platte River of south-central Nebraska was studied at three scales to place the river in its geological context and to trace its evolution through geologic time. At the largest scale the Elm Creek West and the Newark 7.5 minute quadrangles were mapped...

S. M. Condon

2005-01-01

344

Fostering Digital Geologic Maps: The Digital Geologic Map of Mercury from the USGS Atlas of Mercury, Geologic Series  

NASA Astrophysics Data System (ADS)

We present the digital geologic map of Mercury generated from the merge of the USGS Atlas of Mars, Geologic Series originally published by the USGS, and based on Mariner data. This single map offers several advantages over a series of distinct maps.

Frigeri, A.; Federico, C.; Pauselli, C.; Coradini, A.

2009-03-01

345

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

Microsoft Academic Search

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

E. O. Walsh; E. Davis

2008-01-01

346

Geologic Studies in Alaska by the U.S. Geological Survey, 1991.  

National Technical Information Service (NTIS)

The collection of twenty-one papers continues the annual series of U.S. Geological Survey reports on the geology of Alaska. These contributions, which include full-length Articles and shorter Geologic Notes, are grouped under tow broad headings; Mineral R...

D. C. Bradley C. Dusel-Bacon

1992-01-01

347

Geology of interior cratonic sag basins  

SciTech Connect

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

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

1990-05-01

348

American Geological Institute: Educational Resources  

NSDL National Science Digital Library

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

349

Symmetries in geology and geophysics.  

PubMed

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

Turcotte, D L; Newman, W I

1996-12-10

350

Quantitative bedrock geology of Brazil  

NASA Astrophysics Data System (ADS)

We quantitatively analyze the area-age distribution of sedimentary, igneous, metamorphic, and ultramafic bedrock on the basis of data from the digital geologic map of Brazil, published as a GIS map by the Brazilian Geological Survey. Bedrock units exclusively encompassing sedimentary rocks, igneous rocks, or metamorphic rocks cover 40.4%, 31.5%, and 17.7%, respectively, of the total bedrock area. These numbers have to be considered minimum estimates of the areal abundance of sedimentary, igneous, and metamorphic bedrock because polygons defined by mixed lithologies cover ˜8.5-9.5% of the total bedrock area. These mixed units are sedimentary rocks with igneous and/or metamorphic contributions (1.4%), metamorphic rocks with sedimentary contributions (1.2%), metamorphic rocks with igneous contributions (1.5%), igneous rocks with sedimentary and/or metamorphic contributions (4.4%), and ultramafic units with sedimentary, igneous, and/or metamorphic contributions (˜1-2%). The average ages of major lithologic units, weighted according to bedrock area, are as follows: sedimentary rocks (average stratigraphic age of 248 ± 5 [1?] Myr; median stratigraphic age of 87.5 Myr), igneous rocks (1153 ± 13 [1?] Myr), metamorphic rocks (1678 ± 30 [1?] Myr), and ultramafic rocks (˜1227 ± 25 [1?] Myr). The average bedrock age of Brazil is 946 ± 7 [1?] Myr. The range in lithologic composition and age structure of the various bedrock units reflects the complex tectonic makeup of Brazil that ranges from Neogene sedimentary cover in the Amazon Basin to Precambrian cratons (Guyana and Brazilian shields) and Transamazonian greenstone belts. The average spatial resolution of the data is 232 km2 polygon-1 and is sufficient to perform area-age analyses of individual river drainage basins larger than ˜5,000 km2.

Peucker-Ehrenbrink, Bernhard; Miller, Mark W.

2007-05-01

351

CASP: Geological exploration and research  

SciTech Connect

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

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

1995-08-01

352

Geology of the Fargo-Moorehead Region  

NSDL National Science Digital Library

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

Schwert, Donald P.; University, North D.

353

Reservoir geology using 3D modelling tools  

Microsoft Academic Search

The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified.

O. Dubrule; P. Samson; D. Segonds

1996-01-01

354

Geologic History Field Investigation - Minnehaha Falls  

NSDL National Science Digital Library

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

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

355

A megastructural end to Geologic Time  

Microsoft Academic Search

Futuristic nuclear waste disposal projects may have profound implications for the development of Anthropogeomorphology; namely, institution of an Anthropic Rock Cycle within the earth. Some time prior to 12,000 A.D., by construction of a preliminary Dyson heliosphere in the Solar System, Geologic Time could be artificially terminated and the geologic record eventually erased. Here, a new mechanical means of planetary

R. B. Cathcart

1983-01-01

356

Advances in planetary geology, volume 2  

SciTech Connect

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

Not Available

1986-07-01

357

Nabarlek Region, Northern Territory. Geological Map Commentary.  

National Technical Information Service (NTIS)

The area between latitude 12 deg and 12 deg 45 min S and longitudes 133 deg and 144 deg 30 min E, centered 265 km east of Darwin is covered. Stratigraphy, metamorphism, metasomatism, structure economic geology, and geological history are examined.

R. S. Needham

1982-01-01

358

Application of fracture mechanics in geological materials  

Microsoft Academic Search

Application of conventional fracture mechanics concepts to treat crack growth and failure problems in geological media is discussed in this paper. Conventional fracture mechanics methods were developed mainly for metallic materials which exhibit nonlinearity associated mainly with plasticity type responses. Thus, these are not directly applicable to geological materials whose inelastic responses originate from inherent large-scale heterogenities, microcracking, strain softening,

1991-01-01

359

The Second International Geological Congress, Bologna, 1881  

Microsoft Academic Search

The world geological community owes the 2nd Interna- tional Geological Congress (IGC) Bologna 1881 (i) the establishment of a common disciplinary language; (ii) agreement on the basic chronostratigraphical and chrono- logical classification and nomenclature; (iii) agreement on the basic principles for naming the fossil organisms fol- lowing the binomial nomenclature and the priority rule starting with Linnaeus' Systema Naturae (1776

Gian Battista Vai

360

Economic Geology of Lunar Helium-3.  

National Technical Information Service (NTIS)

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 recoverin...

H. H. Schmitt

1988-01-01

361

Worldwide databases in marine geology: A review  

Microsoft Academic Search

This paper provides a review of the major databases relevant to marine geology. Of the 7500 databases studied, about 110 (1.5%) are related to marine geology. Nearly 29% are bibliographic whereas 71% are numeric in nature. Though with shortcomings, there is a potential for subject experts and database developers to build informative and interactive databases. A statistical profile of these

Pravin D. Kunte

1995-01-01

362

Wyoming Geology and Geography, Unit I.  

ERIC Educational Resources Information Center

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

Robinson, Terry

363

RADIO-WAVE METHOD OF GEOLOGICAL MAPPING  

Microsoft Academic Search

Practical methods of using radio waves in geological mapping are considered. The history and basic principles of the method are briefly outlined. When transmitted radio waves penetrate the earth to a definite depth, they induce currents in the heterogeneous geological structures encountered (ore veins, contacts of different rocks, ground-water lenses, for example). The electromagnetic fields of these currents superimposed on

A. D. Frolov

1961-01-01

364

Yellowstone Geologic System Database (GeoGIS)  

NSDL National Science Digital Library

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

Group, University O.

365

Structural Geology Mapping/GIS Software  

NSDL National Science Digital Library

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

Holcombe, Rod

2008-01-14

366

Applications of imaging radar to geology  

Microsoft Academic Search

Tone, texture, and features imaged by radars were studied. A variety of computer image processing techniques were developed to reveal characteristics of these scences. Field checking of sites suggests links between the geology and the images. Tonal studies examine the effects of varying frequency polarization, and illumination geometry. Most surficial geologic units in Death Valley, California, are distinguishable by use

M. I. Daily

1985-01-01

367

US Geological Survey World Energy Project  

NSDL National Science Digital Library

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

368

Wyoming Geology and Geography, Unit I.  

ERIC Educational Resources Information Center

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

Robinson, Terry

369

Geologic Investigations of Underground Coal Mining Problems.  

National Technical Information Service (NTIS)

A series of geological surveys were completed in six coal mines in connection with a Bureau of Mines research program on methane control. The aim of these surveys was to study the overall geology of the coalbed and to use the resulting data to evaluate th...

C. M. McCulloch P. W. Jeran C. D. Sullivan

1975-01-01

370

Structural Geology of the Bermuda Islands  

Microsoft Academic Search

IN conjunction with investigations for the development of a technique for deep-sea seismic measurements that will permit the obtaining of positive geological information on the structure of the ocean basins, we have investigated the structural geology of the Bermuda Islands.

George P. Woolard; Maurice Ewing

1939-01-01

371

Amazing Altered Books  

ERIC Educational Resources Information Center

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

Kieling, Linda W.

2006-01-01

372

Planetary geology and terrestrial analogs in Asia  

NASA Astrophysics Data System (ADS)

2011 PERC Planetary Geology Field Symposium;Kitakyushu City, Japan, 5-6 November 2011 In spite of the extremely diverse geological settings that exist in Asia, relatively little attention has previously been paid to this region in terms of terrestrial analog studies for planetary application. Asia is emerging as a major center of studies in planetary geology, but no attempt had been made in the past to organize a broadly based meeting that would allow planetary geologists in Asia to meet with ones from more advanced centers, such as the United States and Europe, and that would include the participation of many geologists working primarily on terrestrial research. The Planetary Exploration Research Center (PERC) of the Chiba Institute of Technology hosted the first planetary geology field symposium in Asia to present results from recent planetary geology studies and to exchange ideas regarding terrestrial analogs (http://www.perc.it-chiba.ac.jp/meetings/pgfs2011/index.html).

Komatsu, Goro; Namiki, Noriyuki

2012-04-01

373

Geologic Provinces of the United States  

NSDL National Science Digital Library

A look into the forces of plate tectonics, weathering and erosion. A clickable, digital shaded relief map of the United States divides the continental states into 10 regions: Pacific Mountain System, Columbia Plateau, Basin and Range, Colorado Plateau, Rocky Mountain System, Laurentian Upland, Interior Plains, Interior Highlands, Appalachian Highlands, and Atlantic Plain. Each link takes the viewer to a descriptive page that tells of the geologic history of the region and the forces that produced the current landscape. The site is currently under construction; each specific region will soon have links to Sub provinces, Maps and Illustrations (enabled), and an Image Gallery. Links to two other United States Geological Survey (USGS) learning web sites are available: Geologic time and Plate tectonics. Other links are also provided to a list of parks by province or plate tectonic setting, USGS Geology in the Parks home, and National Park Service Park Geology Tour home.

374

The National Geologic Mapping Act of 1992  

SciTech Connect

The well being of any nation is based, in large part, on its ability to locate and prudently use its mineral and water resources; to assess potential harm to its citizens from natural hazards; and to provide for safe disposal of its waste material. These tasks require a detailed knowledge of the character and distribution of geologic materials at or near the surface of the earth, and geologic maps are the principal sources of these types of information. Geologic maps provide essential information regarding the assessment of mineral, energy, and water resources; locating potential sites for the safe disposal of hazardous and nonhazardous waste; land-use planning; earthquake-hazard reduction; predicting volcanic hazards; reducing losses from landslides and other ground failures; mitigating effects of coastal and stream erosion; siting of critical facilities; and basic earth-science research. Geologic maps are the primary sources of geologic information for nearly all decision making related to the habitation of the earth's surface and the use of its resources. Available maps are in continuous use by Federal agencies, state and local governments, private industries, and the general public, but large areas of the US have remained unmapped, or mapped at scales to small to be of general use. Recognizing the increasing National need for geologic maps, the Association of American State Geologists initiated an effort in 1989 to establish a geologic mapping program for the entire US. After developing an implementation plan in concert with the US Geological Survey, the Association of American State Geologists arranged for geologic mapping bills to be introduced simultaneously in both houses of Congress in late 1991. On May 18, 1992, President Bush signed the National Geologic Mapping Act into law.

Haney, D.C. (Univ. of Kentucky, Lexington, KY (United States). Kentucky Geological Survey)

1993-03-01

375

Perlite and Vermiculite (Geology, Exploration and Production Technology).  

National Technical Information Service (NTIS)

Contents: Present state of geological study of perlite and vermiculite resources and problems of further geological prospecting; Perlite, its nature of distribution in the USSR; Transcarpathian perlites; Perlites of Armenia; Results of geological prospect...

V. P. Petrov

1973-01-01

376

Mapping Vesta: A Geological Overview  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

377

THE ROLE OF LITHOLOGY AND ALTERATION ON PERMEABILITY AND FLUID FLOW IN THE YELLOWSTONE GEOTHERMAL SYSTEM, WYOMING  

Microsoft Academic Search

Cores from two of the 13 U.S. Geological Survey (USGS) research holes at Yellowstone National Park (Y-5 and Y-8) were evaluated to characterize lithology, texture, alteration, and the degree and nature of fracturing and veining. Matrix permeability measurements and petrographic examination of the core were used to evaluate the effects of lithology and hydrothermal alteration on permeability. The intervals studied

Patrick Dobson; Jeffrey Hulen; Timothy J. Kneafsey; Ardyth Simmons

378

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

NASA Astrophysics Data System (ADS)

Life has significantly altered the Earth's atmosphere, oceans and crust. To what extent has it also affected interior geological processes? To address this question, three models of geological processes are formulated: mantle convection, continental crust uplift and erosion and oceanic crust recycling. These processes are characterised as non-equilibrium thermodynamic systems. Their states of disequilibrium are maintained by the power generated from the dissipation of energy from the interior of the Earth. Altering the thickness of continental crust via weathering and erosion affects the upper mantle temperature which leads to changes in rates of oceanic crust recycling and consequently rates of outgassing of carbon dioxide into the atmosphere. Estimates for the power generated by various elements in the Earth system are shown. This includes, inter alia, surface life generation of 264 TW of power, much greater than those of geological processes such as mantle convection at 12 TW. This high power results from life's ability to harvest energy directly from the sun. Life need only utilise a small fraction of the generated free chemical energy for geochemical transformations at the surface, such as affecting rates of weathering and erosion of continental rocks, in order to affect interior, geological processes. Consequently when assessing the effects of life on Earth, and potentially any planet with a significant biosphere, dynamical models may be required that better capture the coupled nature of biologically-mediated surface and interior processes.

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

2011-06-01

379

Global Warming in Geologic Time  

SciTech Connect

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

Archer, David (University of Chicago)

2008-02-27

380

Pennsylvania's contribution to petroleum geology  

SciTech Connect

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.

Dickey, P.A.

1991-03-01

381

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

SciTech Connect

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

Fraser Goff; George Guthrie

1999-06-01

382

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

SciTech Connect

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.

Not Available

1991-01-01

383

Geology of Massachusetts and Rhode Island  

USGS Publications Warehouse

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

Emerson, Benjamin Kendall

1917-01-01

384

James Hutton: The Founder of Modern Geology  

NSDL National Science Digital Library

This article reports on the life and influence of James Hutton, considered the founder of modern geology. It covers the existing thinking about Earth's creation, how Hutton's scientific training and his work as a farmer came together in his pursuit of geology, his important contributions to the new science of geology, and the influence his work had on future generations of scientists. The article explains why the boundary between the two rock types at Siccar Point in Scotland is now called the Hutton Unconformity and defines his key concept, the Theory of Uniformitarianism.

385

Review of nuclear techniques in subsurface geology  

SciTech Connect

Nuclear techniques have assumed a major role in obtaining data on geological strata. These techniques require detailed analysis to understand the meaning of the measurements because of the extended region of the interactions and the complications introduced by the borehole environment. In addition, the nuclear parameters that are measured must be related to the geological parameters that are of interest. Types of measurements that can be performed, their relationship to geological parameters, limitations imposed by the need to make measurements in extended media under hostile conditions, and methods to analyze the measurements are presented.

Schweitzer, J.S.; Ellis, D.V.

1988-02-01

386

Tour of Park Geology: Sand Dunes  

NSDL National Science Digital Library

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

387

Geology Fieldnotes: Bryce Canyon National Park, Utah  

NSDL National Science Digital Library

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

Foos, Annabelle

388

Strontium isotopes, a window to the past: researching geological formations at Mount Wapta in the Canadian Rocky Mountains  

Microsoft Academic Search

Variations in the isotopic composition of an element are used as a tool to investigate geological processes. In this study, the variations in the 87 Sr\\/ 86 Sr isotope amount ratio are measured in carbonate minerals to interpret the extent of hydrothermal fluid-rock interactions at a Middle Cambrian site. Although the samples were from different types of altered limestone, those

Michael Wieser

389

Chromite alteration processes within Vourinos ophiolite  

NASA Astrophysics Data System (ADS)

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

Grieco, Giovanni; Merlini, Anna

2012-09-01

390

Modeling the Long-Term Isolation Performance of Natural and Engineered Geologic CO2 Storage Sites  

Microsoft Academic Search

Long-term cap rock integrity represents the single most important constraint on the long-term isolation performance of natural and engineered geologic CO storage sites. CO influx that forms natural accumulations and CO injection for EOR\\/sequestration or saline-aquifer disposal both lead to concomitant geochemical alteration and geomechanical deformation of the cap rock, enhancing or degrading its seal integrity depending on the relative

J W Johnson; J J Nitao; J P Morris

2004-01-01

391

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

SciTech Connect

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

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

1980-01-01

392

Updating of the geological and geothermal research on Milos island  

SciTech Connect

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

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

1989-01-01

393

Geology and Geochemistry of the Lac Cinquante Uranium Deposit, Nunavut  

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

394

Multisource geological data mining and its utilization of uranium resources exploration  

NASA Astrophysics Data System (ADS)

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

Zhang, Jie-Lin

2009-10-01

395

Revised draft: Southeastern Regional geologic characterization report. Volume 1  

SciTech Connect

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

Not Available

1984-11-01

396

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

SciTech Connect

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

Not Available

1984-11-01

397

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

NSDL National Science Digital Library

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

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

398

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

NASA Astrophysics Data System (ADS)

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

Asch, Kristine; Tellez-Arenas, Agnes

2010-05-01

399

Geomorphology in North American Geology Departments, 1971  

ERIC Educational Resources Information Center

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

White, Sidney E.; Malcolm, Marshall D.

1972-01-01

400

Geology and Radiometry of West Macedonia (Greece).  

National Technical Information Service (NTIS)

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

D. G. Minatidis

1984-01-01

401

Geologic distributions of US oil and gas.  

National Technical Information Service (NTIS)

This publication presents nonproprietary field size distributions that encompass most domestic oil and gas fields at year-end 1989. These data are organized by geologic provinces as defined by the American Association of Petroleum Geologists' Committee on...

1992-01-01

402

Alaska Division of Geological & Geophysical Surveys  

NSDL National Science Digital Library

The mission of the Alaska Division of Geological & Geophysical Surveys is "to determine the potential of Alaskan land for production of metals, minerals, fuels, and geothermal resources." The homepage features a "Headlines" area that includes mining reports, links to press releases, and a fascinating interactive map of quaternary faults and folds that will be of great interest to geologists. Moving on, the Sections area contains links to specific department projects, including work on engineering geology, energy resources, and volcanology. Visitors won't want to miss the Geologic Materials Center area. Here they can learn about the Division's work cataloging, storing, and studying key metrics that tell the story of Alaska's geological resources. Finally, the Publications area contains links to all of the organization's written works, including those from the Mineral Industry Research Laboratory at the University of Alaska at Fairbanks and a number of crucial reports from the U.S. Bureau of Mines. [KMG

403

Planetary Geology: Impact Processes on Asteroids.  

National Technical Information Service (NTIS)

The fundamental geological and geophysical properties of asteroids were studied by theoretical and simulation studies of their collisional evolution. Numerical simulations incorporating realistic physical models were developed to study the collisional evo...

C. R. Chapman D. R. Davis R. Greenberg S. J. Weidenschilling

1982-01-01

404

Etymology of Some Common Geologic Terms  

ERIC Educational Resources Information Center

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

Lutz, Alan

1978-01-01

405

Overview of geology, hydrology, geomorphology, and sediment ...  

Treesearch

Science.gov - We Participate ... Description: Within the Deschutes River basin of central Oregon, the geology, hydrology, and physiography ... Modern sediment yield for much of the Deschutes River basin, as determined from reservoir surveys, ...

406

DEEP GEOLOGICAL DISPOSAL RESEARCH IN ARGENTINA  

Microsoft Academic Search

Argentina requires a deep geological repository for the disposal of conditioned spent fuel and high-level waste from two research reactors and two nuclear power plants. Since 1980 to 1990 the first phase of the \\

Carlos A. Ninci; Arturo M. Bevilacqua; Luis A. Jolivet; Elvira R. Maset; Raúl E. Ferreyra; Alicia R. Vullien; Oscar Elena; Luis E. López; Alejandro L. Maloberti; Humberto O. Nievas; Nancy C. Reyes; Juan J. Zarco

407

Early lunar geology and geophysics  

NASA Astrophysics Data System (ADS)

Despite a number of human and robotic missions to the Moon, there are still important unanswered questions about its early evolution, and how it came to be the object we observe today. Here we use observational, experimental, and theoretical techniques to examine three important events that took place early in lunar history and have left a lasting signature. The first event is the formation of the largest basin on the Moon, the South Pole-Aitken Basin. We develop a systematic method to define the previously unknown boundaries of this degraded structure and quantify its gross shape. We also combine a number of remote sensing data sets to constrain the origin of heat producing elements in its interior. The second event we examine is the evolution of the lunar orbit, and the coupling between the Moon's early geophysical properties and the growth of orbital eccentricity. We use analytical models for tidal deformations and orbit evolution to show that the shape of the Moon suggests its early orbit was highly eccentric. However, we are also able to explain the presently high eccentricity entirely by traditional, secular tidal growth while the early Moon was hot. The third event we examine is the magnetization of lunar samples. We perform extensive paleomagnetic measurements of an ancient, deep-seated lunar sample, and determine that a long-lived magnetic field like that of a core dynamo is the most plausible explanation for its magnetic remanence. In sum, the earliest portion of lunar history has been largely obscured by later geologic events, but a great deal can still be learned from this formative epoch. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Garrick-Bethell, Ian

2009-06-01

408

Petroleum geology of East Siberia  

SciTech Connect

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.

Clarke, J.W.

1986-05-01

409

Engineering geological evaluation of geological barrier rocks at landfills and repositories  

Microsoft Academic Search

A site specific evaluation of geological barriers is required for landfills and waste repositories. The waste-repository-rock system has to be taken into consideration for this. Since the geotechnical barrier in conjunction with geological barriers contributes considerably to long-term isolation of the harmful substances from the biosphere, it is absolutely necessary\\u000a to use engineering geology and hydrogeological methods for a quantitative

M. Langer

1998-01-01

410

The virtual landscape of geological information: Topics, methods, and rhetoric in modern geology  

Microsoft Academic Search

Geology is undergoing changes that could influence its knowledge claims, reportedly becoming more laboratory-based, technology-driven, quantitative, and physics- and chemistry-rich over time. This dissertation uses techniques from information science and linguistics to examine the geologic literature of 1945-2005. It consists of two studies: an examination of the geological literature as an expanding network of related subdisciplines, and an investigation of

Sarah Elizabeth Fratesi

2008-01-01

411

The Human side of geologic hazards  

NSDL National Science Digital Library

Students are asked to respond in a way they choose (as a class) to a geologic or weather related hazard. They begin with a study of the event, its causes and local effects. They then research the needs of the people affected. They research charities that serve the population affected. They choose a response (again, as a class). They educate the campus community about the geology/geography of the event, the needs and solicit donations.

Faatz, Renee

412

Scaling geologic reservoir description to engineering needs  

SciTech Connect

This paper evaluates three types of reservoir description models that have been developed for Balmoral field, North Sea, for different applications. A depositional model provides a geological basis for constructing a layer model and for exploration for similar deposits. The layer model provides a framework for calculating reservoir volumetrics. It is concluded that since it provides a flow-unit model integrates geological and petrophysical properties, it provides the most comprehensive description for simulation and reservoir management.

Slatt, R.M. (Arco Research and Technical Services, Plano, TX (US)); Hopkins, G.L. (Arco British Ltd. (GB))

1990-02-01

413

Geology and coal potential of Somaliland  

Microsoft Academic Search

Geological field mapping along with available geological and drilling data suggest that Somaliland (Northwestern Somalia) has favourable stratigraphy and structure for coal deposits. Lignitic to sub-bituminous coal deposits with ages from Jurassic to Oligocene-Miocene occur in various locations across the country including Hed-Hed valley south of Onkhor, Guveneh hills north of Las Dureh and Daban Basin southeast of Berbera. However,

M. Y. Ali

2009-01-01

414

Geology Fieldnotes: Grand Teton National Park, Wyoming  

NSDL National Science Digital Library

This National Park Service resource includes information about geology, park maps, visitor information, photographs, and links to other sites about this park. Geologic information spans the entire history of the park, beginning 2.5 billion years ago (Precambrian) to the present. Details about the different rock types and their formation, mountain building through plate tectonics and the Laramide Orogeny, formation of valleys and canyons, volcanism in the area, and erosion by glaciers are all covered.

415

Tour of Park Geology: Colorado Plateau  

NSDL National Science Digital Library

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

416

Comparison Charts of Geological Processes: Terrestrial Planets  

NSDL National Science Digital Library

This chart presents information on the geological processes (volcanism, impact cratering, tectonics, and gradation) that have affected the Earth, Moon, and the terrestrial planets. Students compare the effects these processes have had on the Moon and planets. There is also a blank chart and a sheet of notes on the geological processes that may be used in conjunction with this chart. This chart is one of the activities for the Exploring Planets in the Classroom's Introduction to the Solar System.

417

GROUNDWATER MODELLING: FROM GEOLOGY TO HYDROGEOLOGY  

Microsoft Academic Search

1. ABSTRACT Three-dimensional mapping has extensively developed in the last decade; geological mapping being the area where these developments are more striking. 3D geological mapping has a myriad of applications in the domains of basin analysis, geophysics, geostatistics, geothermal and energy resources, etc. A parallel domain of development has been three-dimensional groundwater modelling: regional groundwater systems, surface water-groundwater interactions, radioactive

Alfonso Rivera

418

WIPP site and vicinity geological field trip  

SciTech Connect

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.

Chaturvedi, L.

1980-10-01

419

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

420

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

NASA Astrophysics Data System (ADS)

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.

Walsh, E. O.; Davis, E.

2008-12-01

421

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

USGS Publications Warehouse

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

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

1986-01-01

422

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

NASA Astrophysics Data System (ADS)

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.

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

2010-05-01

423

Altered Genes, Altered Metabolism - Longer Life?  

NSDL National Science Digital Library

Studying a tiny worm, Caenorhabditis elegans, scientists discovered that a gene which regulates glucose (sugar) metabolism may also enhance longevity. The principle investigator, Dr. David Finkelstein, says, "this finding suggests that altering glucose metabolism could be a key to slowing aging in higher organisms, even perhaps in humans." Working with a variety of taxa from mice to monkeys, scientists interested in the causes of aging have recently made significant advances in scientists' understanding of the aging process. Researchers have long realized that aging and the pathologies associated with it have evolutionary, physiological and genetic causes, although the relative influence of each of these has been debated. By testing hypotheses in diverse fields, and with a variety of species (from short-lived to long-lived), researchers are growing closer to building an understanding of the mechanisms underlying the aging process.

National Institutes of Health (U.S.). National Institute on Aging.

1997-01-01

424

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

NASA Astrophysics Data System (ADS)

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

Murphy, W. M.

2009-12-01

425

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

NSDL National Science Digital Library

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

426

Geological pattern formation by growth and dissolution in aqueous systems  

Microsoft Academic Search

Although many geological processes take place on time scales that are very long compared with the human experience, essentially all geological processes, fast or slow, are far from equilibrium processes. Surprisingly often, geological processes lead to the formation of quite simple and distinctive patterns, which hint at an underlying simplicity in many complex geological systems.. The ability to predict the

Paul Meakin; B. Jamtveit

2009-01-01

427

From Surface Data to 3D Geologic Maps  

Microsoft Academic Search

New trends in earth sciences are mostly related to technologies allowing graphical representations of the geology in 3D. However, the concept of 3D geologic map is commonly misused. For instance, displays of geologic maps draped onto DEM in rotating perspective views have been misleadingly called 3D geologic maps, but this still cannot provide any volumetric underground information as a true

D. Dhont; P. Luxey; V. Longuesserre; B. Monod; B. Guillaume

2008-01-01

428

The NASA\\/USGS Planetary Geologic Mapping Program  

Microsoft Academic Search

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

K. Tanaka

2006-01-01

429

Geologic setting of the low-level burial grounds  

Microsoft Academic Search

This report describes the regional and site specific geology of the Hanford Sites low-level burial grounds in the 200 East and West Areas. The report incorporates data from boreholes across the entire 200 Areas, integrating the geology of this area into a single framework. Geologic cross-sections, isopach maps, and structure contour maps of all major geological units from the top

K. A. Lindsey; G. K. Jaeger; J. L. Slate; K. J. Swett; R. B. Mercer

1994-01-01

430

Geology Fieldnotes: Death Valley National Park, California/Nevada  

NSDL National Science Digital Library

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

431

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

NASA Astrophysics Data System (ADS)

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.

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

2009-12-01

432

Geologic repositories for radioactive waste: the nuclear regulatory commission geologic comments on the environmental assessment  

Microsoft Academic Search

The NRC staff completed its review of the Environmental Assessments (EAs) issued by the Department of Energy (DOE) in December, 1984, in support of the site selection processes established by the Nuclear Waste Policy Act of 1982 (NWPA). The EAs contain geologic information on nine sites that DOE has identified as potentially acceptable for the first geologic repository in accordance

P. S. Justus; J. S. Trapp; K. B. Westbrook; R. Lee; M. B. Blackford; B. Rice

1985-01-01

433

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

Federal Register 2010, 2011, 2012, 2013

...Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National...2 p.m.-4 p.m. Eastern Standard Time. The Committee will hear updates on progress...2 p.m.-4 p.m. Eastern Standard Time. FOR FURTHER INFORMATION CONTACT:...

2012-02-08

434

Investigating the Geologic Time Scale: Creating posters to Display Trends in Geologic Time  

NSDL National Science Digital Library

This observational inquiry activity involving careful descriptions of rocks and fossil including age will be used to create a scalar accurate geologic time scale. Students will observe and learn that the geologic time scale was created based on changes in fossil, rock, and atmospheric changes.

Atkins, Kim

435

Bureau of Economic Geology. 1978 annual report  

SciTech Connect

Bureau research programs and projects are designed to address many of the State's major concerns in the areas of geologic, energy, mineral, land, and environmental resouces. Research programs incorporate geologic concepts that will build toward an understanding of a specific resource and its impact on human activities. In addition to resource assessments in uranium, lignite, and geopressured geothermal energy, the Bureau continued research into analysis of governmental policy related to energy. Systemic geologic mapping, coastal studies, basin analysis projects, and investigations in other areas of economic geology further indicate the range of research programs carried forward in 1978. Specifically, research on mineral resources and land resources, coastal studies, hydrogeology, basin studies, geologic mapping, and other research (tektites and meteorites, carboniferous of Texas, depositional environments of the Marble Falls Formation, Central Texas) are reported. The establishment of the Mining and Mineral Resources Research Institute is followed. Contracts and grant support and contract reports are listed. The publications eminating from the Bureau are listed. Services rendered by the Bureau and personnel information are included. (MCW)

Not Available

1978-01-01

436

Impact, and its implications for geology  

NASA Astrophysics Data System (ADS)

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.

Marvin, Ursula B.

437

Geological assessment of the greenhouse effect  

SciTech Connect

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

Crowley, T.J. (Texas A M Univ., College Station, TX (United States))

1993-12-01

438

Remote geologic structural analysis of Yucca Flat  

SciTech Connect

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.

Foley, M.G.; Heasler, P.G.; Hoover, K.A. [Pacific Northwest Lab., Richland, WA (United States); Rynes, N.J. [Northern Illinois Univ., De Kalb, IL (United States); Thiessen, R.L.; Alfaro, J.L. [Washington State Univ., Pullman, WA (United States)

1991-12-01

439

Remote geologic structural analysis of Yucca Flat  

SciTech Connect

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.

Foley, M.G.; Heasler, P.G.; Hoover, K.A. (Pacific Northwest Lab., Richland, WA (United States)); Rynes, N.J. (Northern Illinois Univ., De Kalb, IL (United States)); Thiessen, R.L.; Alfaro, J.L. (Washington State Univ., Pullman, WA (United States))

1991-12-01

440

The marine geological record of industrialization  

NASA Astrophysics Data System (ADS)

In the far distant future, what traces of our industrialized civilization could a hypothetical alien visitor to the Earth identify our ever having existed by? Popular perception is of landfills being excavated and species extinctions identified. However, localized terrestrial deposits and loss of only a relatively small proportion of species would be fickle candidates for reliable preservation in the geological record. Rather, the imprint of our current civilization will be seen in a global-scale dissolution-preservation event of carbonate in marine sediments, coupled to a pronounced negative carbon isotopic excursion. This is the geological fingerprint of massive carbon release to the oceans and atmosphere in injunction with the rock weathering consequences of a global warming transient. In this contribution I explore the characteristics of the future marine geological record of industrialization and draw parallels with observations recorded in sediments spanning the Paleocene-Eocene Thermal Maximum.

Ridgwell, A.

2007-12-01

441

Origins of Niagara: A Geological History  

NSDL National Science Digital Library

This site describes the geologic history and current hydrologic and cultural concerns associated with the natural resources of the Niagara region. Many topics are discussed, including the birth of Niagara Falls, the Wisconsin Glacier, rocks and sedimentary deposits, and the future of the falls. Hyperlinks connect one to related histories and facts concerning the Niagara Glen, Devil's Hole, the Niagara River Water Diversion Treaty, and two geologic tables: the Rock of Ages Chart and the Silurian Era Rock Chart. There are thumbnail photos dispersed throughout this document, which display geologic features such as a knick point, a gorge, and strata. A link connects to Thunder Alley, a comprehensive web site about Niagara Falls, of which this site is a part.

Berketa, Rick

442

USGS Coastal and Marine Geology Infobank  

NSDL National Science Digital Library

This clearinghouse provides organized access to U.S. Geological Survey (USGS) coastal and marine data and metadata. The facilities section features material on Coastal and Marine Geology (CMG) regional centers such as maps and information about staff, facilities, labs, research libraries and archives. The Atlas includes maps for specific geographic areas and information about specific types of data within the area such as bathymetry, gravity, magnetics, sampling, and others. The Field Activities section provides information about specific data collection activities (date, place, crew, equipment used, data collected, publications). The Field Activity Collection System (FACS) provides information about field activities (overviews, crew lists, equipment lists, and events). The "Geology School" provides general, broad-based information about earth science concepts, processes and terminology, indexed to keywords. There is also a set of links to additional databases, software tools and viewers, and to related topics.

443

Geologic time: The age of the Earth  

USGS Publications Warehouse

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.

Newman, William L.

1977-01-01

444

Geologic Time: Eons, Eras, and Epochs  

NSDL National Science Digital Library

This resource guide from the Middle School Portal 2 project, written specifically for teachers, provides links to exemplary resources including background information, lessons, career information, and related national science education standards. This publication contains resources designed to do three things. The first is to complement teacher content knowledge and its relationship to the nature of geologic science. Geology is not a laboratory based science lending itself to traditional notions of controlled experiments, rather it is a historical science requiring different methods. Second, we supply teachers with various student centered, hands-on/minds-on activities to develop student understanding, and third, we provide career oriented resources to expose students to scientists whose work involves concepts in geologic time.

Lefever, Mary

2007-09-01

445

Geology Resources: The University of Texas of the Permian Basin  

NSDL National Science Digital Library

The University of Texas of the Permian Basin (UTPB) has a well-regarded geology program, and they have created this engaging site to profile the geology of their unique corner of West Texas. Their geology resources page contains the following sections: "Geological Overview", "West Texas Geology", "Interesting Links", "Road Logs", "Cores & Samples & Topo Maps", and "Presentations". The "Geological Overview" area offers a brief rundown of the geological milieu surrounding the UTPB campus. Moving on, the site really comes alive in "West Texas Geology", with insightful descriptions of the Basin and Range Province, faults, folds, igneous intrusions, and a relief map of Texas. Those with a penchant for travel will be delighted with the "Road Logs" area. Essentially, they are geological tour guides for persons driving from Midland to Van Horn, the Guadalupe Mountains, and other locations. Overall, it's a well-done site, and one that visitors will want to share with friends.

446

Method of fracturing a geological formation  

DOEpatents

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.

Johnson, James O. (2679-B Walnut, Los Alamos, NM 87544)

1990-01-01

447

Application of remote sensing to California's geology  

SciTech Connect

Recent improvements in remote sensing from spacecraft and aircraft are providing unique opportunities for scientists to study the earth. Observations and measurements can be made with greater accuracy, precision, and resolution than ever before. The following article discusses how current remote sensing data can be used to further the understanding of California's diverse and complex geology. Topics which are discussed include: wavelength intervals used in remote sensing; systems used; interpretation of images; digital processing of images; geological applications in California; and future improvements in remote sensing. 28 references.

Higgins, C.T.; Streitz, R.

1988-06-01

448

Geology Fieldnotes: Ice Age National Scientific Preserve  

NSDL National Science Digital Library

This National Park Service (NPS) site gives information on the Ice Age National Scientific Preserve in Wisconsin, including geology, park maps, a photo album, and other media (books, videos, CDs). There is also a selection of links to other geologic and conservation organizations, and to information for visitors. This preserve contains a wealth of glacial features associated with the most recent Pleistocene continental glaciation including drumlins, kames, kettles, moraines, erratics, and eskers. It also contains a segment of the Ice Age National Scenic Trail, a 1000-plus mile hiking and backpacking trail that passes through this unique glacial landscape.

449

Spatial Visualization in Introductory Geology Courses  

NASA Astrophysics Data System (ADS)

Visualization is critical to solving most geologic problems, which involve events and processes across a broad range of space and time. Accordingly, spatial visualization is an essential part of undergraduate geology courses. In such courses, students learn to visualize three-dimensional topography from two-dimensional contour maps, to observe landscapes and extract clues about how that landscape formed, and to imagine the three-dimensional geometries of geologic structures and how these are expressed on the Earth's surface or on geologic maps. From such data, students reconstruct the geologic history of areas, trying to visualize the sequence of ancient events that formed a landscape. To understand the role of visualization in student learning, we developed numerous interactive QuickTime Virtual Reality animations to teach students the most important visualization skills and approaches. For topography, students can spin and tilt contour-draped, shaded-relief terrains, flood virtual landscapes with water, and slice into terrains to understand profiles. To explore 3D geometries of geologic structures, they interact with virtual blocks that can be spun, sliced into, faulted, and made partially transparent to reveal internal structures. They can tilt planes to see how they interact with topography, and spin and tilt geologic maps draped over digital topography. The GeoWall system allows students to see some of these materials in true stereo. We used various assessments to research the effectiveness of these materials and to document visualization strategies students use. Our research indicates that, compared to control groups, students using such materials improve more in their geologic visualization abilities and in their general visualization abilities as measured by a standard spatial visualization test. Also, females achieve greater gains, improving their general visualization abilities to the same level as males. Misconceptions that students carry obstruct learning, but are largely undocumented. Many students, for example, cannot visualize that the landscape in which rock layers were deposited was different than the landscape in which the rocks are exposed today, even in the Grand Canyon.

Reynolds, S. J.

2004-12-01

450

Discrete computer analysis in petroleum geology  

SciTech Connect

Computer analysis must not be resembling on geologist`s work, having its own way because of uncertainty and shortness of geological information even on mature stage of exploration, when our original system of formal discrete computer analysis, realised on {open_quotes}FoxPro for Windows{close_quotes} with not substantial but probabilistic (without ever driving the usual maps) representation of geological situation was used for picking out the sets of best points for exploration drilling in south part of Dheprovsko-Donetzky oil-gas basin.

Zakharian, A.Z.

1995-08-01

451

Devils Postpile National Park Geologic Story  

NSDL National Science Digital Library

This website of the United States Geological Survey (USGS) and the National Park Service (NPS) highlights the geology of Devils Postpile National Monument in California. Beginning with the origin of the Sierra Nevada Mountains 150 million years ago, the story continues on to the rocks of Devils Postpile, which formed 100,000 years ago from basaltic lava. There is a description of the cracking and columnar jointing that formed the 'posts', and why some of them are not straight but curved. Information also includes other volcanic rocks in and near the monument, recent earthquakes, weathering, and a summary of the volcanic and glacial history of the area.

452

The Slippery Slope of Litigating Geologic Hazards  

NSDL National Science Digital Library

Based on a lawsuit brought against the County of Los Angeles by homeowners suing over damage caused by the Portuguese Bend Landslide, this case study teaches students principles of landslide movement while illustrating the difficulties involved with litigation resulting from natural hazards. Students first read a fictitious newspaper article (based on the actual events), then receive details about the geologic setting and landslide characteristics. With this information, the students are then asked to evaluate the possible causes of the disaster. The case was developed for use in a non-majorsâ introductory course in environmental geology.

Ozsvath, David

453

Arabian plate hydrocarbon geology and potential  

SciTech Connect

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

Beydoun, Z.R.

1991-01-01

454

The Geologic History of Seawater  

NASA Astrophysics Data System (ADS)

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

Holland, H. D.

2003-12-01

455

Azithromycin alters macrophage phenotype  

Microsoft Academic Search

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

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

2008-01-01

456

The Geologic Context of Water-altered Minerals in Valles Marineris  

NASA Astrophysics Data System (ADS)

We investigated hematite and sulfate (polyhydrated sulfates and kieserite) sites throughout the Valles Marineris complex, with a variety of remote-sensing tools, in order to better understand the correlation between different mineral types and their likel

Chojnacki, M.; Hynek, B. M.

2007-03-01

457

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

Microsoft Academic Search

The Westwood Au-Zn-Cu deposit, one of the latest major discoveries made in the Abitibi Subprovince, is hosted by the Bousquet Formation of the Archean Blake River Group, Abitibi Subprovince. The Bousquet Formation forms a south-facing, steeply dipping homoclinal volcanic sequence. Three mineralized corridors from the north to the south have been defined to date: 1) the Zone 2 Extension Corridor,

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

2009-01-01

458

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

Microsoft Academic Search

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

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

2007-01-01

459

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

460

Magellan stereo images and Venusian geology  

NASA Astrophysics Data System (ADS)

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.

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

1992-12-01

461

Alteration/minerals information extraction from EO-1 Hyperion data  

NASA Astrophysics Data System (ADS)

Satellite-based hyper-spectral imaging became a reality in November 2000 with the successful launch and operation of the Hyperion system on board the EO-1 platform. Hyperion is a pushbroom imager with 220 spectral bands in the 400-2500 nm wavelength range, a 30-meter pixel size and a 7.5 km swath. The objective of this research is to use the Hyperion image for deriving the Rocks/Minerals Information. This paper introduces a complete processing flow from raw Hyperion image to geological theme information map, including radiance calibration and correction, atmospheric correction and geometrical correction, feature extraction and Selection, and spectral mapping by multi-method on the base of referring to the USGS spectral library and ground radiometric measurement data. The study explored the utility of Hyperion data in alteration mineral mapping. Two Hyperion images of the BeiYa in the northwest of YunNan was acquired and evaluated for alteration zone mapping. The results show that the alteration zones in the study area can be identified from Hyperion data very efficiently. The mineralogical and lithologic information extracted from Hyperion data is largely consistent with the geological map and previous research results.

Wang, Zhenghai; Hu, Guangdao

2006-10-01

462

Geology Fieldnotes: Yellowstone National Park, Wyoming/Idaho/Montana  

NSDL National Science Digital Library

This Yellowstone National Park site contains park geology information, photographs, related links, visitor information, multimedia resources, and teacher features (resources for teaching geology with National Park examples). The park geology section discusses the Park's geologic history, structural geology, and describes many of the geologic sites and wildlife found in the park. It describes the sites found on the routes from Old Faithful to Mammoth Springs (East Thumb, Old Faithful, Midway, Lower, and Norris geysers, geyser basins, Gibbon Falls), Mammoth Springs to Tower Junction and the Canyon (Undine Falls, Lava Creek, Lamar Valley, Hayden Valley), and at the Yellowstone Lake area (West Thumb and Grant Village).

463

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

NASA Astrophysics Data System (ADS)

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.

House, P. K.

2008-12-01

464

Compositional changes induced by hydrothermal alteration at the Red Mountain alunite deposit, Lake City, Colorado. Bulletin  

SciTech Connect

Red Mountain, on the eastern margin of the 23.1-Ma Lake City caldera (Hon, 1987), Lake City, Colo., hosts one of the largest replacement alunite deposits in the western United States (more than 70 million metric tons of alunite). Chemical analyses of 35 samples selected from both altered and fresh rocks from Red Mountain were analyzed to evaluate chemical changes within the major alteration assemblages. The paper briefly summarizes the geology of Red Mountain, presents the mass-balance data, and discusses the implications of these data with respect to mineralogic changes within the alteration assemblages.

Bove, D.J.; Hon, K.

1990-01-01