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Sample records for drillholes ol-kr40 ol-kr42

  1. Basic Data Report for Drillhole SNL-2 (C-2948)

    SciTech Connect

    Powers, Dennis W.

    2005-01-19

    SNL-2 was drilled in the northwest quarter of Section 12, T22S, R30E, in eastern Eddy County, New Mexico (Figure 2-1). It is located 574 ft from the north line (fnl) and 859 ft from the west line (fwl) of the section (Figure 2-2). This location places the drillhole east of the Livingston Ridge escarpment among oil wells of the Cabin Lake field. SNL-2 will be used to test hydraulic properties and to monitor ground water levels of the Culebra Dolomite Member of the Permian Rustler Formation. SNL-2 was permitted by the New Mexico State Engineer as C-2948. [Official correspondence regarding permitting and regulatory information must reference this permit number.] In the plan describing the integrated groundwater hydrology program (Sandia National Laboratories, 2003), SNL-2 is also codesignated WTS-1 because the location also satisfies needs for long-term monitoring of water quality and movement in the Culebra Dolomite for RCRA permitting; this program is under the management of Washington TRU Solutions LLC (WTS). In the event that additional wells are established on the SNL-2 drillpad to monitor other hydrological units (e.g., the Magenta Dolomite Member of the Permian Rustler Formation), the current drillhole will likely be referred to as SNL-2C because it is completed in the Culebra. Most drillholes at WIPP have been described after completion to provide an account of the geology, hydrology, or other basic data acquired during drilling and immediate completion of the drillhole. In addition, the basic data report provides an account of the drilling procedures and activities that may be helpful to later interpretations of data or for further work in the drillhole, including test activities and eventual plugging and abandoning activities. The basic data report also provides a convenient means of reporting information about administrative activities necessary to drill the hole.

  2. Permeability and porosity of the Illinois UPH 3 drillhole granite and a comparison with other deep drillhole rocks

    USGS Publications Warehouse

    Morrow, C.A.; Lockner, D.A.

    1997-01-01

    Permeability, porosity, and volumetric strain measurements were conducted on granite cores obtained at depths of 0.7 to 1.6 km from the Illinois UPH 3 drillhole at effective confining pressures from 5 to 100 MPa. Initial permeabilities were in the range of 10-17 to 10-19 m2 and dropped rapidly with applied pressure to values between 10-20 and 10-24 m2 at 100 MPa, typical of other deep granite core samples. These values are several decades lower than equivalent weathered surface granites at comparable effective confining pressures, where weathering products in cracks and pores inhibit crack closure with applied pressure. Permeabilities of the Illinois cores were inversely related to sample depth, suggesting that stress relief and thermal microfractures induced during core retrieval dominated the fluid flow. Thus these samples provide an upper bound on in situ matrix permeability values. A comparison of core permeability from UPH 3 and other deep drillholes shows that stress relief damage can often dominate laboratory permeability measurements. We conclude that it may be difficult to make meaningful estimates of in situ permeability based on either borehole samples (possible damage during retrieval) or surface-derived analogs (altered by weathering). Volumetric strain determined from porosity measurements was compared with differential strain analysis (DSA) data reported by other investigators on samples from the same depths in the drillhole. Our strain measurements (0.002 to 0.005 at 100 MPa) were nearly twice as large as the DSA values, probably because of the crack-enhancing effects of fluids present in our samples that are absent in the dry DSA cores, as well as other time-dependent deformation effects. This difference in observed strain magnitudes between the two measurement methods may be an important consideration if strain and/or porosity data from deep core samples are used in models of stress, fluid circulation, and excess fluid pressure generation in the

  3. Basic Data Report for Drillhole SNL-9 (C-2950)

    SciTech Connect

    Dennis W. Powers; Washington Regulatory and Environmental Services

    2005-01-19

    SNL-9 (permitted by the State Engineer as C-2950) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation within a proposed re-entrant of the margin of halite dissolved from the upper part of the Salado near Livingston Ridge. SNL-9 is located in the southeast quarter of section 23, T22S, R30E, in eastern Eddy County, New Mexico. SNL-9 was drilled to a total depth of 845 ft below the ground surface. Below surface dune sand and the Berino soil, SNL-9 encountered, in order, the Mescalero caliche, Gatuna, Dewey Lake, Rustler, and uppermost Salado Formations. Two intervals were cored: 1) from the lower Forty-niner Member through the Magenta Dolomite and into the upper Tamarisk Member; and 2) from the lower Tamarisk Member through the Culebra Dolomite and Los Meda?os Members and into the uppermost Salado Formation. Geophysical logs were acquired from the open hole to total depth, and the drillhole was successfully completed with a screened interval open across the Culebra.

  4. Basic Data Report for Drillhole SNL-5 (C-3002)

    SciTech Connect

    Dennis W. Powers; Washington Regulatory and Environmental Services

    2005-01-18

    SNL-5 (permitted by the New Mexico State Engineer as C-3002) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation in an area north of the Waste Isolation Pilot Plant (WIPP) site where data are sparse and where a pumping or monitoring well for the northern pumping test is needed. SNL-5 is located in the southeast quarter of section 6, T22S, R31E, in eastern Eddy County, New Mexico. SNL-5 was drilled to a total depth of 687 ft below ground level (bgl), based on driller's measurements. Below the caliche pad, SNL-5 encountered the Mescalero caliche, Gatu?a, Dewey Lake, and Rustler Formations. Two intervals of the Rustler were cored: (1) from the lower Forty-niner Member through the Magenta Dolomite and into the upper Tamarisk Member; and (2) from the lower Tamarisk Member through the Culebra Dolomite and into the upper Los Meda?os Members. Geophysical logs were acquired from the open hole to a depth of ~672 ft. No water was observed to flow into the open drillhole until the Culebra was penetrated. includes horizontal beds and laminae near the base, and the uppermost part shows some inclined bedding. The mudstone unit shows mostly reddish brown claystone and siltstone with some gray mottling. Clasts or intraclasts are also included in the unit. The upper Tamarisk sulfate is somewhat brecciated near the base.

  5. Basic Data Report for Drillhole SNL-12 (C-2954)

    SciTech Connect

    Dennis W. Powers

    2005-01-20

    SNL-12 (permitted by the New Mexico State Engineer as C-2954) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation near the margin of dissolution of halite in the upper part of the Salado south of the Waste Isolation Pilot Plant (WIPP). SNL-12 is located in the southeast quarter of section 20, T23S, R31E, in eastern Eddy County, New Mexico. SNL-12 was drilled to a total depth of 905 ft below the ground level. Below surface dune sand and the Berino soil, SNL-12 encountered, in order, the Mescalero caliche, Gatu?a, Dewey Lake, Rustler, and uppermost Salado Formations. Two intervals were cored: (1) from the lower Forty-niner Member through the Magenta Dolomite and into the upper Tamarisk Member; and (2) from the lower Tamarisk Member through the Culebra Dolomite and Los Meda?os Members and into the uppermost Salado Formation. Geophysical logs were acquired from the open hole to total depth, and the drillhole was successfully completed with a screened interval open across the Culebra. At SNL-12, the uppermost Salado cores display displacive halite crystals in clastic-rich units below an amalgamated sulfate at the top of the formation. There is no indication of thinning of the upper Salado due to postdepositional dissolution, and this is consistent with predrilling expectations.

  6. Milankovitch cycles in electrical resistivity logs from the Toa Baja scientific drillhole, Puerto Rico

    SciTech Connect

    Maltezou, F.; Anderson, R.N. )

    1991-03-01

    Milankovitch cycles in the upper part of the Toa Baja drillhole, detected by geophysical logs, are used to estimate sedimentation rates, and to localize the depths at which sedimentation rate changes occur. The log-derived age information is then combined with reference dates from palaeontological data and the Vail' global sea-level curve to build a detailed record of the chronology of the upper stratigraphic sequence in the well.

  7. Basic data report for drilling and hydrologic testing of drillhole DOE-2 at the Waste Isolation Pilot Plant (WIIP) site

    SciTech Connect

    Mercer, J.W.; Beauheim, R.L.; Snyder, R.P.; Fairer, G.M.

    1987-04-01

    Drillhole DOE-2 was drilled to investigate a structural depression marked by the downward displacement of stratigraphic markers in the Salado Formation. Contrary to several hypotheses, halite layers were thicker in the lower part of the Salado, not thinner as a result of any removal of halite. The upper Castile anhydrite in Drillhole DOE-2 is anomalously thick and is strongly deformed relative to the anhydrite in adjacent drillholes. In contrast, the halite was <8 ft thick and significantly thinner than usually encountered. The lower Castile anhydrite appears to be normal. The depression within the correlated marker beds in the Salado Formation in Drillhole DOE-2 is interpreted as a result of gravity-driven deformation of the underlying Castile Formation. Several stratigraphic units were hydrologically tested in Drillhole DOE-2. Testing of the unsaturated lower portion of the Dewey Lake Red Beds was unsuccessful because of exceptionally small rates of fluid intake. Drill-stem tests were conducted in five intervals in the Rustler Formation, over the Marker Bed 138-139 interval in the Salado formation, and over three sandstone members of the Bell Canyon Formation. A pumping test was conducted in the Culebra Dolomite Member of the Rustler Formation. Pressure-pulse tests were conducted over the entire Salado Formation. Fluid samples were collected from the Culebra Dolomite Member and from the Hays Member of the Bell Canyon Formation. 31 refs., 31 figs., 5 tabs.

  8. A study of the mineralogy and lithology of cuttings from the U.S. Bureau of Reclamation MESA 6-2 Drillhole, Imperial County, California, including comparisons with MESA 6-1 Drillhole

    USGS Publications Warehouse

    Fournier, R.B.

    1976-01-01

    The Mesa 6-2 drillhole penetrates 6,000 feet of sediments in Imperial County, California. The cuttings material from the upper part of the drillhole is chiefly unconsolidated mud and silt. Soft siltstone fragments occur at about 1,400 feet and increase in amount down to 2,400 feet. Some pebbles are found above 2,400 feet, but the pebble-rich horizons are less distinctive than the pebble zone in the Mesa 6-1 drillhole. Below 2,400 feet, cuttings ape composed of about two-thirds siltstone and one-third sandstones, ranging from very fine to very coarse sand, plus loose Sand grains. Although below 2,400 feet there is no systematic change in color of siltstones, grain size, or cementation with depth, horizons composed predominantly of loose sand are more common at deeper levels. Fragments of igneous and metamorphic rocks are less common than in the Mesa 6-1 drillhole. Quartz, calcite, K-feldspar, plagioclase (albite), illite, and mixed layer clays are identified by X-ray diffractograms of whole-rock samples throughout the hole. Chlorite occurs in all samples from below 2,100 feet, and probably also occurs at shallower depths. In most siltstones, montmorillonite occurs only down to the interval 2,200-2,300 feet, but in the buff siltstone it is found to the bottom of the drillhole. Kaolinite occurs at least down to 4,700 feet. Dolomite is found down to at least 5,970 feet, but is generally absent from horizons composed mostly of loose sand. Pyrite occurs in many samples. No zeolites, ankerite, or amorphous sulfur were detected. Theme is no horizon that may be used fop conclusive correlation with the Mesa 6-1 drillhole.

  9. Potential contributions of metamorphic petrology studies in an ultra-deep drillhole in the southern Appalachians

    SciTech Connect

    Speer, J.A.

    1985-01-01

    The proposed, ultra-deep hole in the southeast U.S. will penetrate allochthonous, medium- to high-grade metamorphic rocks of the Inner Piedmont and Blue Ridge thrust sheets. It is anticipated that the hole will then encounter autochthonous low-grade, metasedimentary cover rocks before bottoming out in crystalline Precambrian basement rocks. Metamorphic petrology in the recent past has concentrated on unraveling the physical and chemical history (P, T, X/sub fluid/, etc.) of metamorphic rocks. The techniques that have been developed are ideally suited to the study of relatively limited samples from drill core. Detailed studies of the allochthonous and autochthonous rocks from the drillhole, combined with comparable studies of the surface rocks, by metamorphic petrologists experimented with these approaches, would give a 3-dimensional picture of the PTX evolution in the region of the ultra-deep hole, and thus an idea of the geometrical, chemical, and physical changes the rocks experienced. This would place constraints on conditions of the rocks before and after thrusting and thus any tectonic models of thrusting in the southern Appalachians. With limited sampling this could be a problem, with more complete sampling it will be an advantage. The metamorphic petrology of the rocks will provide basic support for the other studies of the drill core and drillhole, most notably geochronology and stable isotopes. It should not be forgotten that in addition to the historical metamorphism, the expected, present-day conditions in the drillhole are those of burial metamorphism. The hole will present an excellent opportunity to study such active metamorphic conditions.

  10. Experimental Investigation on the Basic Law of the Fracture Spatial Morphology for Water Pressure Blasting in a Drillhole Under True Triaxial Stress

    NASA Astrophysics Data System (ADS)

    Huang, Bingxiang; Li, Pengfeng

    2015-07-01

    The present literature on the morphology of water pressure blasting fractures in drillholes is not sufficient and does not take triaxial confining stress into account. Because the spatial morphology of water pressure blasting fractures in drillholes is not clear, the operations lack an exact basis. Using a large true triaxial water pressure blasting experimental system and an acoustic emission 3-D positioning system, water pressure blasting experiments on cement mortar test blocks (300 mm × 300 mm × 300 mm) were conducted to study the associated basic law of the fracture spatial morphology. The experimental results show that water pressure blasting does not always generate bubble pulsation. After water pressure blasting under true triaxial stress, a crushed compressive zone and a blasting fracture zone are formed from the inside, with the blasting section of the naked drillhole as the center, to the outside. The shape of the outer edges of the two zones is ellipsoidal. The range of the blasting fracture is large in the radial direction of the drillhole, where the surrounding pressure is large, i.e., the range of the blasting fracture in the drillhole radial cross-section is approximately ellipsoidal. The rock near the drillhole wall is affected by a tensile stress wave caused by the test block boundary reflection, resulting in more flake fractures appearing in the fracturing crack surface in the drillhole axial direction and parallel to the boundary surface. The flake fracture is thin, presenting a small-range flake fracture. The spatial morphology of the water pressure blasting fracture in the drillhole along the axial direction is similar to a wide-mouth Chinese bottle: the crack extent is large near the drillhole orifice, gradually narrows inward along the drillhole axial direction, and then increases into an approximate ellipsoid in the internal naked blasting section. Based on the causes of the crack generation, the blasting cracks are divided into three

  11. Basic data report for drillholes at the H-11 complex (Waste Isolation Pilot Plant-WIPP)

    SciTech Connect

    Mercer, J.W. ); Snyder, R.P. )

    1990-05-01

    Drillholes H-11b1, H-11b2, and H-11b3 were drilled from August to December 1983 for site characterization and hydrologic studies of the Culebra Dolomite Member of the Upper Permian Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico. In October 1984, the three wells were subjected to a series of pumping tests designed to develop the wells, provide information on hydraulic communication between the wells, provide hydraulic properties information, and to obtain water samples for quality of water measurements. Based on these tests, it was determined that this location would provide an excellent pad to conduct a convergent-flow non-sorbing tracer test in the Culebra dolomite. In 1988, a fourth hole (H-11b4) was drilled at this complex to provide a tracer-injection hole for the H-11 convergent-flow tracer test and to provide an additional point at which the hydraulic response of the Culebra H-11 multipad pumping test could be monitored. A suite of geophysical logs was run on the drillholes and was used to identify different lithologies and aided in interpretation of the hydraulic tests. 4 refs., 6 figs., 6 tabs.

  12. Physical-Property Measurements on Core samples from Drill-Holes DB-1 and DB-2, Blue Mountain Geothermal Prospect, North-Central Nevada

    USGS Publications Warehouse

    Ponce, David A.; Watt, Janet T.; Casteel, John; Logsdon, Grant

    2009-01-01

    From May to June 2008, the U.S. Geological Survey (USGS) collected and measured physical properties on 36 core samples from drill-hole Deep Blue No. 1 (DB-1) and 46 samples from drill-hole Deep Blue No. 2 (DB-2) along the west side of Blue Mountain about 40 km west of Winnemucca, Nev. These data were collected as part of an effort to determine the geophysical setting of the Blue Mountain geothermal prospect as an aid to understanding the geologic framework of geothermal systems throughout the Great Basin. The physical properties of these rocks and other rock types in the area create a distinguishable pattern of gravity and magnetic anomalies that can be used to infer their subsurface geologic structure. Drill-holes DB-1 and DB-2 were spudded in alluvium on the western flank of Blue Mountain in 2002 and 2004, respectively, and are about 1 km apart. Drill-hole DB-1 is at a ground elevation of 1,325 m and was drilled to a depth of 672 m and drill-hole DB-2 is at a ground elevation of 1,392 m and was drilled to a depth of 1522 m. Diameter of the core samples is 6.4 cm. These drill holes penetrate Jurassic and Triassic metasedimentary rocks predominantly consisting of argillite, mudstone, and sandstone; Tertiary diorite and gabbro; and younger Tertiary felsic dikes.

  13. A note on drillhole depths required for reliable heat flow determinations

    USGS Publications Warehouse

    Chapman, D.S.; Howell, J.; Sass, J.H.

    1984-01-01

    In general, there is a limiting depth in a drillhole above which the reliability of a single determination of heat flow decreases rapidly with decreasing depth and below which the statistical uncertainty of a heat flow determination does not change perceptibly with increasing depth. This feature has been established empirically for a test case comprising a group of twelve heat flow sites in the Republic of Zambia. The technique consists of constructing heat flow versus depth curves for individual sites by progressively discarding data from the lower part of the hole and recomputing heat flow from the remaining data. For the Zambian test case, the curves converge towards a uniform value of 67 ?? 3 mW m-2 when all available data are used, but values of heat flow calculated for shallow(< 100 m) parts of the same holes range from 45 to 95 mW m-2. The heat flow versus depth curves are enclosed by a perturbation envelope which has an amplitude of 40 mW m-2 at the surface and decreases linearly to the noise level at 190 m. For the test region of Zambia a depth of 170 m is needed to guarantee a heat flow measurement within ?? 10% of the background regional value. It is reasonable to expect that this depth will be shallower in some regions and deeper in others. Features of heat flow perturbation envelopes can be used as quantitative reliability indices for heat flow studies. ?? 1984.

  14. "Intelligent design" of a 3D reflection survey for the SAFOD drill-hole site

    NASA Astrophysics Data System (ADS)

    Alvarez, G.; Hole, J. A.; Klemperer, S. L.; Biondi, B.; Imhof, M.

    2003-12-01

    SAFOD seeks to better understand the earthquake process by drilling though the San Andreas fault (SAF) to sample an earthquake in situ. To capitalize fully on the opportunities presented by the 1D drill-hole into a complex fault zone we must characterize the surrounding 3D geology at a scale commensurate with the drilling observations, to provide the structural context to extrapolate 1D drilling results along the fault plane and into the surrounding 3D volume. Excellent active-2D and passive-3D seismic observations completed and underway lack the detailed 3D resolution required. Only an industry-quality 3D reflection survey can provide c. 25 m subsurface sample-spacing horizontally and vertically. A 3D reflection survey will provide subsurface structural and stratigraphic control at the 100-m level, mapping major geologic units, structural boundaries, and subsurface relationships between the many faults that make up the SAF fault system. A principal objective should be a reflection-image (horizon-slice through the 3D volume) of the near-vertical fault plane(s) to show variations in physical properties around the drill-hole. Without a 3D reflection image of the fault zone, we risk interpreting drilled anomalies as ubiquitous properties of the fault, or risk missing important anomalies altogether. Such a survey cannot be properly costed or technically designed without major planning. "Intelligent survey design" can minimize source and receiver effort without compromising data-quality at the fault target. Such optimization can in principal reduce the cost of a 3D seismic survey by a factor of two or three, utilizing the known surface logistic constraints, partially-known sub-surface velocity field, and the suite of scientific targets at SAFOD. Our methodology poses the selection of the survey parameters as an optimization process that allows the parameters to vary spatially in response to changes in the subsurface. The acquisition geometry is locally optimized for

  15. Analysis of borehole televiewer measurements in the Vorotilov drillhole, Russia - First results

    USGS Publications Warehouse

    Huber, K.; Fuchs, K.; Palmer, J.; Roth, F.; Khakhaev, B.N.; Van-Kin, L. E.; Pevzner, L.A.; Hickman, S.; Moos, D.; Zoback, M.D.; Schmitt, D.

    1997-01-01

    In the Eurasian part of the World Stress Map almost the whole region east of the Tornquist-Teisseyre line is terra incognita. The closure of this information gap is of fundamental importance to the understanding of the geodynamics of the Eurasian continent. A detailed analysis of stress-induced wellbore breakouts has been performed over a 4.1-km-long depth interval in the Vorotilov drillhole (VGS). The borehole is located in the central part of the Russian platform, right in the center of the Vorotilov meteorite impact crater 60 km to the NNE of the city of Nizni Novgorod. An ultrasonic borehole televiewer (BHTV) was used to obtain high-resolution acoustical images from the borehole wall. With an interactive system for analyzing BHTV data the azimuth and shape of borehole breakouts occurring in the depth range of 1.3-4.8 km were analyzed. A statistical analysis of the resulting orientation profile of the breakout azimuths yields an overall direction of the maximum horizontal principal stress SH of N 137??E ?? 15??. Variations of breakout orientation with depth ranging from a few degrees up to more than 90?? are seen on various depth scales. The observed stress direction of N 137??E agrees very well with the average SH orientation of N 145??E in Central Europe. If this measurement is taken as representative for the Russian platform, the stress field in Russia is only slightly rotated in comparison to Central Europe. This can possibly be interpreted as indicative for the stress field to be governed by broad scale tectonic forces, such as a strong contribution from the forces exerted by the collision zone in the Alpine-Himalayan belt and by the Mid-Atlantic ridge.

  16. Basic Data Report for Drillholes on the H-19 Hydropad (Waste Isolation Pilot Plant--WIPP)

    SciTech Connect

    Mercer, J.W.; Cole, D.L.; Holt, R.M.

    1998-10-09

    Seven holes were drilled and wells (H-19b0, H-19b2, H-19b3, H-19b4, H-19b5, H-19b6, and H-19b7) were constructed on the H-19 hydropad to conduct field activities in support of the Culebra Transport Program. These wells were drilled and completed on the Waste Isolation Pilot Plant (WIPP) site during February to September 1995. An eighth hole, H-19b1, was drilled but had to be abandoned before the target depth was reached because of adverse hole conditions. The geologic units penetrated at the H-19 location include surficial deposits of Holocene age, rocks from the Dockum Group of Upper Triassic age, the Dewey Lake Redbeds, and Rustler Formation of the Permian age. The Rustler Formation has been further divided into five informal members which include the Forty-niner Member, Magenta Member, Tamarisk Member, Culebra Dolomite Member, and an unnamed lower member. The Rustler Formation, particularly the Culebra Dolomite Member, is considered critical for hydrologic site characterization. The Culebra is the most transmissive saturated unit above the WIPP repository and, as such, is considered to be the most likely pathway for radionuclide transport to the accessible environment in the unlikely event the repository is breached. Seven cores from the Culebra were recovered during drilling activities at the H-19 hydropad and detailed descriptions of these cores were made. On the basis of geologic descriptions, four hydrostratigraphic units were identified in the Culebra cores and were correlated with the mapping units from the WFP air intake shaft. The entire length of H-19b1 was cored and was described in detail. During coring of H-19b1, moisture was encountered in the upper part of the Dewey Lake Redbeds. A 41-ft-thick section of this core was selected for detailed description to qualify the geologic conditions related to perched water in the upper Dewey Lake. In addition to cuttings and core, a suite of geophysical logs run on the drillholes was used to identify and

  17. Geothermal reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes

    USGS Publications Warehouse

    McKenzie, W.F.; Truesdell, A.H.

    1977-01-01

    The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested as a geothermometer in three areas of the western United States. Limited analyses of spring and borehole fluids and existing experimental rate studies suggest that dissolved sulfate and water are probably in isotopic equilibrium in all reservoirs of significant size with temperatures above ca. 140??C and that little re-equilibration occurs during ascent to the surface. The geothermometer is, however, affected by changes in ??18O of water due to subsurface boiling and dilution and by addition of sulfate of nearsurface origin. Methods are described to calculate the effects of boiling and dilution. The geothermometer, is applied to thermal systems of Yellowstone Park, Wyoming, Long Valley, California, and Raft River, Idaho to estimate deep reservoir temperatures of 360, 240, and 142??C, respectively. ?? 1976.

  18. Geologic Characterization of Young Alluvial Basin-Fill Deposits from Drill-Hole Data in Yucca Flat, Nye County, Nevada

    USGS Publications Warehouse

    Sweetkind, Donald S.; Drake II, Ronald M.

    2007-01-01

    Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site in Nye County, Nevada, that has been the site of numerous underground nuclear tests; many of these tests occurred within the young alluvial basin-fill deposits. The migration of radionuclides to the Paleozoic carbonate aquifer involves passage through this thick, heterogeneous section of Tertiary and Quaternary rock. An understanding of the lateral and vertical changes in the material properties of young alluvial basin-fill deposits will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating ground-water flow in the Yucca Flat area. This report by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, presents data and interpretation regarding the three-dimensional variability of the shallow alluvial aquifers in areas of testing at Yucca Flat, data that are potentially useful in the understanding of the subsurface flow system. This report includes a summary and interpretation of alluvial basin-fill stratigraphy in the Yucca Flat area based on drill-hole data from 285 selected drill holes. Spatial variations in lithology and grain size of the Neogene basin-fill sediments can be established when data from numerous drill holes are considered together. Lithologic variations are related to different depositional environments within the basin such as alluvial fan, channel, basin axis, and playa deposits.

  19. Discovery of microdiamond in the Åreskutan Nappe of the Seve Nappe Complex, overlying the COSC-1 drillhole

    NASA Astrophysics Data System (ADS)

    Klonowska, Iwona; Janák, Marian; Majka, Jarosław; ‎ Froitzheim, Nikolaus; Gee, David G.

    2015-04-01

    The Seve Nappe Complex (SNC) crops out for about 800 km along the Scandian mountain belt in northwestern Sweden. In the central Scandes of Jämtland and Tröndelag, the SNC has been mapped 200 km westards into the hinterland, via the Tömmerås and Trollheimen antiforms into the northern parts of the Western Gneiss Region. The Complex is dominated by psammitic metasediments and amphibolites derived from dolerites, basalts and gabbros (locally ultramafites) comprising an outer continental margin assemblage, inferred to represent the Cryogenian-Ediacaran, extended outer margin of Baltica. Although most of the SNC is in amphibolite facies, eclogites and garnet peridotites are locally preserved both in Sweden and farther west in Trollheimen. More pelitic metasediments occur at higher levels in the Complex and the high grade metamorphism is usually accompanied by partial melting and leucogranites. Isotope dating indicates that HP/UHP metamorphism is of mostly of Ordovician age and related to continent-arc subduction during closure of the Iapetus Ocean. In recent years, closer investigation of the high grade metamorphism has led not only to the identification of UHP assemblages in the eclogites and garnet peridotites (Janák et al. 2013, Klonowska et al. 2014), but also that the host paragneisses contain clear evidence of subduction (Majka et al. 2014), with microdiamond inclusions in garnet. Most recently on Åreskutan (Klonowska et al., this volume), on the mountain top above the COSC-1 drillhole, diamond-bearing gneisses have been found. Garnets in Åreskutan gneisses are characterized by inclusion-rich cores. Graphite, carbonates, quartz and CO2-fluid inclusions together with diamonds and moissanite are concentrated in swarms. Garnets are homogeneous, almandine-rich (Alm65-68Prp26-33Grs3-5Sps2-3). However, the highest grossular content is observed in garnet cores (5mol.%). Phengite is characterized by Si content of 3.19-3.47 apfu. Thermodynamic modelling indicates

  20. Mechanical properties of fractures from drillholes, UE25-NRG-4; USW-NRG-6; USW-NRG-7; USW-SD-9, at Yucca Mountain, Nevada

    SciTech Connect

    Olsson, W.A.; Brown, S.R.

    1997-01-01

    Rock cores from drillholes UE25-NRG-4, USW-NRG-6, USW-NRG-7, and USW-SD-9 containing natural fractures were obtained from the Sample Management Facility at Yucca Mountain, Nevada. All recoverable fractures were sheared at constant normal stresses from 2.5 to 15 MPa, in the as-received condition (air-dry). Detailed profilometer data were collected from each fracture surface before testing. The tests yielded the normal closure as a function of normal stress, and the shear stress and dilation as functions of shear offset. The constitutive properties obtained from these stress-displacement relations were: normal stiffness, shear stiffness, shear strength, and dilation angle at peak shear stress. Shear strength plotted against normal stress for four thermomechanical units shows that friction angle varies from 370 to 460 and cohesion varies from 0.02 to 1.71 MPa.

  1. A SMALL-ANGLE DRILL-HOLE WHIPSTOCK

    DOEpatents

    Nielsen, D.E.; Olsen, J.L.; Bennett, W.P.

    1963-01-29

    A small angle whipstock is described for accurately correcting or deviating a drill hole by a very small angle. The whipstock is primarily utilized when drilling extremely accurate, line-of-slight test holes as required for diagnostic studies related to underground nuclear test shots. The invention is constructed of a length of cylindrical pipe or casing, with a whipstock seating spike extending from the lower end. A wedge-shaped segment is secured to the outer circumference of the upper end of the cylinder at a position diametrically opposite the circumferential position of the spike. Pin means are provided for affixing the whipstock to a directional drill bit and stem to alloy orienting and setting the whipstock properly in the drill hole. (AEC)

  2. Basic Data Report for Drillhole SNL-3 (C-2949)

    SciTech Connect

    Dennis W. Powers; Washington Regulatory and Environmental Services

    2005-01-20

    SNL-3 (permitted by the New Mexico State Engineer as C-2949) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation within a dissolution reentrant north of the WIPP site and well east of Livingston Ridge. SNL-3 is located in the southeast quarter of section 34, T21S, R31E, in eastern Eddy County, New Mexico. SNL-3 was drilled to a total depth of 970 ft below ground level (bgl). Below surface dune sand, SNL-3 encountered, in order, the Mescalero caliche, Gatuna, Dewey Lake, Rustler, and upper Salado Formations. Two intervals were cored: (1) from the lower Forty-niner Member through the Magenta Dolomite and into the upper Tamarisk Member; and (2) from the lower Tamarisk Member through the Culebra Dolomite and Los Meda?os Members and into the uppermost Salado.

  3. Basic Data Report for Drillhole SNL-1 (C-2953)

    SciTech Connect

    Dennis W. Powers; Washington Regulatory and Environmental Services

    2005-01-19

    SNL-1 (permitted by the New Mexico State Engineer as C-2953) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation near the margin of dissolution of halite in the upper Permian Salado Formation in the northeast arm of Nash Draw. SNL-1 is located in the northwest quarter of section 16, T21S, R31E, in eastern Eddy County, New Mexico, and it is adjacent to the tailings pile of Mississippi Potash Incorporated (now Intrepid) East mine to test for the presence of shallow zones that might include brine infiltrated from the tailings pile. SNL-1 was drilled to a total depth of 644 ft below ground level (bgl). Below surface wash, SNL-1 encountered, in order, the Mescalero caliche, Dewey Lake, and Rustler Formations.

  4. Small drill-hole, gas mini-permeameter probe

    DOEpatents

    Molz, III, Fred J.; Murdoch, Lawrence C.; Dinwiddie, Cynthia L.; Castle, James W.

    2002-01-01

    The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.

  5. Small drill-hole, gas mini-permeameter probe

    DOEpatents

    Molz, III, Fred J.; Murdoch, Lawrence C.; Dinwiddie, Cynthia L.; Castle, James W.

    2002-12-03

    The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.

  6. Basic data report for drillhole AEC 8 (Waste Isolation Pilot Plant - WIPP). [Eddy County, New Mexico

    SciTech Connect

    Not Available

    1983-01-01

    AEC 8 was originally drilled in 1974 to a depth of 3028 ft by Oak Ridge National Laboratory as part of the initial investigations of a site for radioactive waste disposal. In 1976, Sandia National Laboratories deepened the borehole from the top of the Castile Formation into the Bell Canyon Formation to test the hydraulic properties of the Bell Canyon. The borehole encountered in descending order Holocene sands (20 ft), Mescalero caliche (6 ft), Santa Rosa Sandstone (143 ft), Dewey Lake Redbeds (491 ft), Rustler Formation (322 ft), Salado Formation (1990 ft), Castile Formation (1335 ft), and the upper Bell Canyon Formation (603 ft). The borehole stratigraphy is in normal order and there is no significant deformation. An extensive suite of geophysical logs provides information on the lithology and stratigraphy. The potentiometric surfaces of Bell Canyon fluid-bearing zones are 550 ft (for the zone at 4821 ft to 4827 ft) and 565 ft below land surface (for the zone at 4844 to 4860 ft). The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level wastes.

  7. Basic data report for drillhole WIPP 30 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    Not Available

    1980-04-01

    WIPP 30 was drilled in east-central Eddy County, New Mexico, in NW 1/4, Sec. 33, T21S, R31E, to obtain drill core for the study of dissolution of near-surface rocks. The borehole encountered from top to bottom, the Dewey Lake Red Beds (449' including artificial fill for drill pad), Rustler Formation (299'), and the upper 160' of the Salado Formation. Continuous core was cut from the surface to total depth. Geophysical logs were taken the full length of the borehole to measure acoustic velocities, density, and distribution of potassium and other radioactive elements. Information from this borehole will be included in an interpretive report on dissolution in Nash Draw based on combined borehole data, surface mapping and laboratory analyses of rocks and fluids. The WIPP is to demonstrate (through limited operations) disposal technology for transuranic defense wastes and to then be converted to a repository. The WIPP will also provide research facilities for interactions between high-level waste and salt. Administration policy as of February 1980 is to hold the WIPP site in reserve until the first disposal site can be chosen from several potential sites, including the WIPP.

  8. Basic data report for drillhole WIPP 32 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    1980-11-01

    WIPP 32 is an exploratory borehole drilled to examine the subsurface at a small topographic high in Nash Draw. The borehole is located in east-central Eddy County, New Mexico, in NE 1/4 SE 1/4 Sec. 33, T.22S., R.29E. and was drilled in August, 1979. The hole was drilled to a depth of 390 feet, and encountered, from top to bottom, the Rustler Formation (166') and the upper Salado Formation (224'). Core was taken from 4 to 353 feet. Geophysical logs were run the full length of the hole to measure formation properties. The WIPP is to demonstrate (through limited operations) disposal technology for transuranic defense wastes. The WIPP will also provide facilities to research interactions between high-level waste and salt.

  9. Basic data report for drillhole ERDA 9 (Waste Isolation Pilot Plant WIPP)

    SciTech Connect

    Not Available

    1983-01-01

    ERDA 9 was drilled in eastern Eddy County, New Mexico, to investigate and test salt beds for the disposal of nuclear wastes. The hole was placed near the SE corner of section 20, T22S,R31E. It was drilled between April 28 and June 4, 1976, to a depth of 2889 ft (measured from a kelly bushing altitude of 3,420.4 ft MSL). The borehole encountered, from top to bottom, Holocene deposits (including artificial fill) of 22 ft, the Pleistocene Mescalero Caliche (5 ft) and Gatuna Formation (27 ft), 9 ft of the Triassic Santa Rosa Sandstone, and 487 ft of the Dewey Lake Red Beds, 290 ft of the Rustler Formation, 1976 ft of the Salado Formation and 53 ft of the Castile Formation, all of Permian age. Cuttings were collected at 5-ft intervals for the land surface to a depth of 1090 ft, and consecutive cores were taken to a depth of 2876.6 ft. A suite of wireline geophysical logs was run the full length of the borehole to measure distribution of radioactive elements and hydrogen, and variations in rock density and elastic velocity. On the basis of the borehole findings and related hydrological and geophysical programs, the site was judged suitable to pursue the extensive geological characterization program which followed. The core from ERDA 9 provided a suite of samples extensively tested for rock mechanics, physical properties, and mineralogy. Drill-stem tests in ERDA 9 indicated no significant fluids or permeability in the Salado beds of interest. The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level wastes.

  10. Frictional strength of cuttings and core from SAFOD drillhole phases 1 and 2

    USGS Publications Warehouse

    Tembe, S.; Lockner, D.A.; Solum, J.G.; Morrow, C.A.; Wong, T.-F.; Moore, Diane E.

    2006-01-01

    We investigated the frictional properties of drill cuttings and core obtained from 1.85-3.1 km true vertical depth in the SAFOD scientific borehole in central California. Triaxial frictional sliding experiments were conducted on samples from primary lithologic traits and significant shear zones, including the inferred active trace of the San Andreas fault. The samples were deformed at room temperature under constant effective normal stresses of 10, 40, and 80 MPa with axial shortening rates of 0.01-1.0 ??m s-1. The weakest samples were from shale, claystone, and siltstone units with friction coefficient ?? = 0.4-0.55. Stronger samples were from quartzo-feldspathic rocks with ?? ??? 0.6. Materials tested from two shear, zones at 2560 and 3067 m measured depth had ?? = 0.4-0.55 and velocity strengthening behavior consistent with fault creep at depths <4 km. The coefficient of friction for bulk samples from the inferred trace of the San Andreas fault was ???0.6. Copyright 2006 by the American Geophysical Union.

  11. Basic data report for Drillhole WIPP 33 (Waste Isolation Pilot Plant-WIPP)

    SciTech Connect

    1981-02-01

    WIPP 33 is an exploratory borehole to investigate the nature of unusually thick fill material in the northwest portion of the WIPP site; a breccia pipe was considered a possible, though unlikely, cause of the fill. The borehole is located in Section 13, T22S, R30E, in east central Eddy County, New Mexico and was drilled during July, 1979. The hole was drilled to a depth of 840 feet, and encountered, from top to bottom, surficial Holocene deposits (44 ft including artificial fill for drill pad), the Dewey Lake Red Beds (457 ft), the Rustler Formation (276 ft) and the upper portion of the Salado Formation (163 ft). Selected intervals were cored, and cuttings were taken for examination by geologists. Geophysical logs were taken the full length of the borehole to measure radioactivity, resistivity and density. The stratigraphic profile was found to be normal, and no breccia was observed.

  12. Basic data report for drillhole WIPP 11 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    Not Available

    1982-02-01

    Seismic reflection data from petroleum industry sources showed anomalous reflectors in the Castile Formation over a small area about 3 miles north of the center of the Waste Isolation Pilot Plant (WIPP) site. Additional corroborative seismic reflection data were collected as part of WIPP investigations, and WIPP 11 was drilled to investigate the anomaly. WIPP 11 was drilled near the northwest corner of Section 9, T.22.S., R.31E. it penetrated, in descending order, sand dune deposits and the Gatuna Formation (29'), Santa Rosa Sandstone (132'), Dewey Lake Red Beds (502'), Rustler Formation (288'), Salado Formation (1379'), and most of the Castile Formation (1240'). Beds within the lower part of the Salado, and the upper anhydrite of the Castile, are thinner than normal; these beds are displaced upward structurally by the upper Castile halite which is highly thickened (about 968'). The lowest halite is thin (51') and the basal anhydrite was not completely penetrated. Subsequent seismic and borehole data has shown WIPP 11 to be in a structural complex now identified as the disturbed zone. The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level waste, though there are no plans at this time to dispose of high level waste or spent fuel at WIPP.

  13. Basic data report for Drillhole WIPP 22 (Waste Isolation Pilot Plant, WIPP)

    SciTech Connect

    Not Available

    1980-03-01

    WIPP 22 is an exploratory borehole whose objective is to determine the nature of the near-surface formations after seismic information indicated a possible fault. The borehole is located in section 20, T.22S., R.31E., in eastern Eddy County, New Mexico, and was drilled between March 14 and 30, 1978. The hole was drilled to a depth of 1448 feet and encountered, from top to bottom, surficial Holocene deposits (6', including artificial fill for drill pad), the Mescalero caliche (7'), the Santa Rosa Sandstone (68'), the Dewey Lake Red Beds (492'), the Rustler Formation (311'), and the upper portion of the Salado Formation (565'). Cuttings were collected at 10-foot intervals. A suite of geophysical logs was run to measure acoustic velocities, density, and radioactivity. On the basis of comparison with other geologic sections drilled in the area, the WIPP 22 section is a normal stratigraphic sequence and it does not show structural disruption. The WIPP is to demonstrate (through limited operations) disposal technology for transuranic defense wastes. The WIPP will also provide facilities to research interactions between high-level waste and salt.

  14. Basic data report for drillhole WIPP 21 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    Not Available

    1980-03-01

    WIPP 21 is an exploratory borehole whose objective is to determine the nature of the near-surface formations after seismic information indicated a possible fault. The borehole is located in section 20, T.22S., R.31E., in eastern Eddy County, New Mexico, and was drilled between May 24 and 26, 1978. The hole was drilled to a depth of 1046 feet and encountered, from top to bottom, surficial Holocene deposits (6', including artificial fill for drill pad), the Mescalero caliche (6'), the Santa Rosa Sandstone (34'), the Dewey Lake Red Beds (487'), the Rustler Formation (308'), and the upper portion of the Salado Formation (178'). Cuttings were collected at 10-foot intervals. A suite of goephysical logs was run to measure acoustic velocities, density, and radioactivity. On the basis of comparison with other geologic sections drilled in the area, the WIPP 21 section is a normal stratigraphic sequence and it does not show structural disruption. The WIPP is to demonstrate (through limited operations) disposal technology for transuranic defense wastes. The WIPP will also provide facilities to research interactions between high-level waste and salt.

  15. Basic data report for drillhole WIPP 15 (Waste Isolation Pilot Plant-WIPP)

    SciTech Connect

    Not Available

    1981-11-01

    WIPP 15 is a borehole drilled in Marformation.h, 1978, in section 18, T.23S., R. 35E. of south-central Lea County. The purpose of WIPP 15 was to examine fill in San Simon Sink in order to extract climatic information and to attempt to date the collapse of the sink. The borehole was cored to total depth (810.5 feet) and encountered, from top to bottom, Quaternary calcareous clay, marl and sand, the claystones and siltstones of the Triassic Santa Rosa Formation. Neutron and gamma ray geophysical logs were run to measure density and radioactivity. The sink was about 547 feet of Quaternary fill indicating subsidence and deposition. Diatomaceous beds exposed on the sink margin yielded samples dated by /sup 14/C at 20,570 +- 540 years BP and greater than 32,000 years BP; these beds are believed stratigraphically equivalent to ditomaceous beds at 153 to 266 feet depth in the core. Aquatic fauna and flora from the upper 98 feet of core indicate a pluvial period (probably Tohokan) followed by an arid or very arid time before the present climate was established. Aquifer pump tests performed in the Quaternary sands and clays show transmissivities to be as high as 600 feet squared per day. As the water quality was good, the borehole was released to the lessee as a potential water well.

  16. Basic data report for drillhole ERDA 6 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    Not Available

    1983-01-01

    ERDA 6 was drilled in eastern Eddy County, New Mexico, to investigate a candidate site for a nuclear waste repository. The site was subsequently rejected on the basis of geological data. ERDA 6 was drilled in the NE 1/4 SE 1/4, section 35, T21S,R31E. The borehole encountered, from top to bottom, 17 ft of Quaternary deposits, 55 ft of the Triassic Santa Rosa Sandstone, 466 ft of the Dewey Lake Red Beds, 273 ft of the Rustler Formation, 1785.5 ft of the Salado Formation and 374.5 ft of the upper Castile Formation, all of Permian age. Cores or drill cuttings were taken throughout the hole. A suite of wireline geophysical logs was run to a depth of 883 ft to facilitate the recognition and correlation of rock units, to assure identification of major lithologies and to provide depth determinations independent of drill-pipe measurements. The site at ERDA 6 was rejected because the structure of the lower Salado and the Castile is too severe to develop a repository along a single set of beds. The borehole also intersected a reservoir of pressurized brine and gas at about 2710'. The pore volume for the reservoir was estimated to be in the range from about 200,000 to about 2 million barrels. ERDA 6 was re-entered in 1981 by the Department of Energy (DOE) for the purpose of further testing the brine reservoir. Those tests are described in separate reports by the DOE and its contractors. The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level wastes.

  17. Permeability of Whole Core Samples of Chelungpu Fault, Taiwan TCDP Scientific Drillhole

    NASA Astrophysics Data System (ADS)

    Lockner, D. A.; Morrow, C.; Song, S.; Tembe, S.; Wong, T.

    2005-12-01

    We are measuring material properties of core samples from the 2000 meter Taiwan Continental Drilling Program (TCDP) borehole crossing the Chelungpu fault (activated during the 1999 M7.6 Chi-Chi earthquake). Measurements include permeability, intact strength, frictional sliding strength and poroelastic storativity. Initial tests are concentrating on permeability and storativity of undisturbed whole core samples spanning approximately 60 m including the main shear zones identified at depths of 1111 m and 1151 m. The 1111 m shear zone is believed to have slipped nearly 10 meters during the Chi-Chi earthquake. Formation rock types vary from shales to mudstones to graywacke. Pervasively high clay content throughout the core suggested that samples would be sensitive to salinity of the pore fluid used during testing. This was confirmed by spot tests of strength and permeability versus pore water salinity. (Increased salinity increased strength, Young's modulus and permeability.) Consequently, all TCDP samples were tested with 1 molar KCl pore fluid. Permeability results are therefore expected to represent upper bounds on in-situ values. Whole core permeabilities measured at 15.5 MPa effective confining pressure (appropriate for 1111 m depth) ranged from 0.4 to 7 x 10-20 m2, with the lowest values near the axis of the 1111 m shear zone. At this same effective pressure, storativity was in the range 1.3 to 7 x 10-11 Pa-1 and preliminary measurements of coefficient of friction were 0.55 to 0.75. Apparently, even fault `core' samples contain sufficient quartz and other hard grains to sustain moderate to high frictional strength. The northern segment of the Chi-Chi earthquake which slid on the Chelungpu fault showed an unusual combination of suppressed high frequency seismic radiation and large total slip, leading to the suggestion that deformation was enhanced by high transient pore fluid pressure. Our observations of low permeability, low storativity and high frictional strength make this section of the Chelungpu fault a good candidate for thermally-induced fluid pressurization and dynamic weakening during the Chi-Chi earthquake.

  18. The geologic structures observed in drillhole DOE-2 and their possible origins: Waste Isolation Pilot Plant

    SciTech Connect

    Borns, D.J.

    1987-07-01

    Questions remain as the origins of evaporite deformation within the Salado and Castile formations. Two miles north of the WIPP site, a stacked sequence of depressions was indicated by shallow boreholes. Such structures raise questions regarding the role of dissolution and gravity tectonics at the WIPP site. To investigate these structures, DOE drilled hole DOE-2 north of the WIPP site. At DOE-2, the downward displacement of stratigraphic markers in the Salado confirmed the presence of stacked depressions, which were the primary target of the drilling program. The halitic units between the marker beds were thickened compared to the average section determined from basin-wide drilling. The remaining question is whether dissolution occurred in the underlying Castile and resulted in the deformation of the Salado. Markers in the anhydrite units indicate recumbent structures and thickening of the anhydrite units by folding. As a consequence, the Castile Formation is nearly its average thickness, with the folded thickness of anhydrite compensating for the missing halite. The nearby thickening of halite within the Castile, the absence of relic anhydrite laminae in the attenuated halite units, and the high strain fabric of the remaining halite suggest that dissolution was not the dominant process in the Castile. The favored hypothesis for the Castile structures is salt flow in response to gravity inversion of the anhydrite and halite units of the Castile. 21 refs., 18 figs.

  19. Geothermal research on the 2.5 km deep COSC-1 drillhole, Central Sweden

    NASA Astrophysics Data System (ADS)

    Pascal, Christophe; Beltrami, Hugo; Daly, Stephen; Juhlin, Christopher; Kukkonen, Ilmo; Long, Mike; Rath, Volker; Renner, Joerg; Schwarz, Gerhard; Sundberg, Jan

    2015-04-01

    The scientific drilling project "Collisional Orogeny in the Scandinavian Caledonides" (COSC), supported by ICDP and the Swedish Research Council, involves the drilling of two boreholes through carefully selected sections of the Paleozoic Caledonian orogen in Central Sweden. COSC-1, the first of the two planned boreholes, was drilled and fully cored down to 2.5 km depth during spring and summer 2014 near the town of Åre. The COSC working group is organised around six thematic teams including us, the geothermal team. The major objectives of the COSC geothermal team are: a) to contribute to basic knowledge about the thermal regime of Palaeozoic orogenic belts, ancient shield areas and high heat-producing plutons; b) to refine knowledge on climate change at high latitudes (i.e. Scandinavia), including historical global changes, recent palaeoclimate development (since last ice age) and expected future trends; c) to determine the vertical variation of the geothermal gradient, heat flow and thermal properties down to 2.5 km, and to determine the required corrections for shallow (< 1 km) heat flow data; d) to explore the geothermal potential of the Åre-Järpen area; e) to explore to what degree the conductive heat transfer is affected by groundwater flow in the uppermost crust and f) to evaluate the heat generation input and impact from the basement and the alum shales. To reach these targets the following tasks were carried out or are planned: 1) heat flow predictions from shallow boreholes; 2) geophysical logging; 3) analyses of logs and well tests; (3) determination of rock thermal properties on core samples; 4) determination of heat generation rates from radiometric and geochemical studies; 5) fracture characterisation for permeability and convective heat flow estimations; 6) analysis of convective signals; 7) analysis of paleoclimatic signals; 8) heat flow modelling and evaluation of geothermal potential and 9) Fennoscandia heat flow map compilation. The purpose of the present contribution is to summarise the tasks completed so far and to present the on-going research by the COSC geothermal team.

  20. Predicted variation of stress orientation with depth near an active fault: application to the Cajon Pass Scientific Drillhole, southern California

    USGS Publications Warehouse

    Wesson, R.L.

    1988-01-01

    Preliminary measurements of the stress orientation at a depth of 2 km interpreted to indicate that the regional orientation of the maximum compression is normal to the fault, and taken as evidence for a very weak fault. The orientation expected from plate tectonic arguments is about 66?? NE from the strike of the fault. Geodetic data indicate that the orientation of maximum compressive strain rate is about 43?? NE from the strike of the fault, and show nearly pure right-lateral shear acting parallel to the fault. These apparent conflicts in the inferred orientation of the axis of maximum compression may be explained in part by a model in which the fault zone is locked over a depth interval in the range of 2-5 to 15 km, but is very weak above and below that interval. This solution does require, however, a few mm/yr of creep at the surface on the San Andreas or nearby sub-parallel faults (such as the San Jacinto), which has not yet been observed, or a shallow zone near the faults of distributed deformation. -from Author

  1. Description of drill-hole VIIIV core from the Jabiluka unconformity-type uranium deposit, Northern Territory, Australia

    SciTech Connect

    Nutt, C.J.

    1984-01-01

    The Jabiluka unconformity-type uranium deposit is one of four large unconformity-type deposits in the Alligator Rivers Uranium Field in the eastern part of the Pine Creek geosyncline, Northern Territory, Australia. These unconformity-type uranium deposits occur as veins, disseminations, and breccia matrix in metasedimentary rocks of the Lower Proterozoic Cahill Formation and are near a regional unconformity that separates the Cahill from the sedimentary rocks of the Middle Proterozoic Kombolgie Formation. The study of unconformity-type deposits - a new type of uranium deposit typified by deposits discovered in the past 15 years in Australia and Canada - is part of the US Geological Survey uranium program; funding was also provided by the US Department of Energy National Uranium Resource Evaluation (NURE) program. Pancontinental Mining Limited kindly gave us access to Jabiluka core and made their geological and geophysical data available for inclusion in our reports. Data and interpretations from the mineralogy and stratigraphy of Jabiluka should aid in defining characteristics and setting of these world class deposits and guide exploration for similar deposits in the United States. 3 refs., 6 figs., 1 tab.

  2. The Silent Canyon Caldera Complex--A three-dimensional model based on drill-hole stratigraphy and gravity inversion

    SciTech Connect

    Sawyer, D.A.; Anderson, M.L.; Hildenbrand, T.G; McKee, E.H.; Rowley, P.R.

    1999-12-13

    The structural framework of Pahute Mesa, nevada, is dominated by the Silent Canyon caldera complex, a buried, multiple collapse caldera complex. Using the boundary surface between low density Tertiary volcanogenic rocks and denser granitic and weakly metamorphosed sedimentary rocks (basement) as the outer faults surfaces for the modeled collapse caldera complex, it is postulated that the caldera complex collapsed on steeply dipping arcuate faults two, possibly three, times following eruption of at least two major ash-flow tuffs. The caldera and most if its eruptive products are now deeply buried below the surface of Pahute Mesa. Relatively low-density rocks in the caldera complex produce one of the largest gravity lows in the western conterminous United States.

  3. Thermochronometry using red TL of quartz - a feasibility study from in-situ drill-hole samples

    NASA Astrophysics Data System (ADS)

    Schmidt, Christoph; Zöller, Ludwig

    2015-04-01

    Thermochronometry - the revelation of the temperature history of rock related to subsidence or uplift and erosion - relies on methods with closure temperatures >40-70 °C, such as (U-Th-Sm)/He or fission track analysis on apatite. These methods are applicable to young and tectonically active mountain ranges, but results of calculated mean denudation rates are too imprecise for older orogens. Several studies attested the quartz luminescence signal (325 °C TL peak, OSL fast component) isothermal decay at ambient temperatures as low as 56 °C (Prokein and Wagner, 1994; Herman et al., 2010; de Sarkar et al., 2013). The so far determined closure temperatures of the quartz luminescence thermochronometry system vary between ~35 °C for the OSL fast component (Herman et al., 2010) and ~70 °C for red thermoluminescence (RTL; Tsuchiya and Fujino, 2000) and are dependent on the cooling rate and the charge trap parameters. Although featuring a favourably low closure temperature - thus allowing to study the geologically most recent temperature history -, especially quartz OSL suffers from low dose saturation, limiting the application to highly erosive orogens. Saturation doses of RTL exceed those of OSL by a factor of 10 or more (Fattahi and Stokes, 2000), what opens up new perspectives in low-temperature thermochronometry. We here present experimental results on the general suitability of RTL for thermochronometry, obtained for samples from a drilling hole in the granitic basement of the Variscan Fichtelgebirge (Franconia, Germany). The samples allowed studying the RTL signal saturation level in-situ at different ambient temperatures up to ~55 °C (at 1831 m depth). Measurements confirmed depletion of the 325 °C RTL peak for ambient temperatures >25 °C, most probably for even lower temperatures. Irradiation experiments showed that the RTL signal is not in saturation for ambient temperatures >25 °C, even for this 'old' mountain range. We could further demonstrate that the luminescence sensitivity of samples strongly increases with rising ambient temperature, opposite to the findings of Ypma and Hochman (1991) for samples from sedimentary basins. References Fattahi, M., Stokes, S., 2000. Extending the time range of luminescence dating using red TL (RTL) from volcanic quartz. Radiation Measurements 32, 479-485. Herman, F., Rhodes, E.J., Braun, J., Heiniger, L., 2010. Uniform erosion rates and relief amplitude during glacial cycles in the Southern Alps of New Zealand, as revealed from OSL-thermochronology. Earth and Planetary Science Letters 297, 183-189. Prokein, J., Wagner, G.A., 1994. Analysis of thermoluminescent glow peaks in quartz derived from the KTB-drill hole. Radiation Measurements 23, 85-94. de Sarkar, S., Mathew, G., Pande, K., Chauhan, N., Singhvi, A.K., 2013. Rapid denudation of Higher Himalaya during late Pleistocence, evidence from OSL thermochronology. Geochronometria 40, 304-310. Tsuchiya, N., Fujino, K., 2000. Evaluation of cooling history of the Quaternary Takidani pluton using thermoluminescence technique. Proceedings World Geothermal Congress, Kyushu-Tohoku, Japan. Ypma, P.J., Hochman, M.B., 1991. Thermoluminescence geothermometry - a case study of the Otway basin. APEA Journal, 312-324.

  4. Sedimentary cover in the South Western Desert of Egypt as deduced from Bouguer gravity and drill-hole data

    NASA Astrophysics Data System (ADS)

    Senosy, M. M.; Youssef, M. M.; Abdel Zaher, M.

    2013-06-01

    The Western Desert, Egypt includes the major groundwater aquifer in the country. It is apart from the Major Sahara Nubian Aquifer which is present in Sudan, Chad, Egypt and Libya. Thickness of this aquifer is changed laterally from south to north and also from west to east. The changes may structurally or litheologicalley control. The present study is focused on using of Bouguer gravity anomaly mapped at a scale of 1:500,000 and the lithological logs of about 120 deep wells used to determine the thickness of the sedimentary sequence containing the main Nubian sandstone water aquifer in important area of Egypt. The area is located in the southern part of the Western Desert bounded by the latitudes 22°00'-26°30'N, and longitudes 28°30'-33°00'E. The predominant structures affecting the basement rocks and the sedimentary cover were traced and analyzed. The gravity stripping approach was applied to eliminate the gravity effects caused by sedimentary sequence and to separate density anomalies within the sedimentary fill from the influence of rocks at deeper levels in the crystalline crust. The study indicated that the surface of the basement rocks is highly rugged and mostly controlled by structures which have a direct effect on thickness variation of the sedimentary cover all over the area. Regionally the area is characterized by two major intracratonic basins (the Dahkla Basin and the Nile valley Basin) separated by a NE-SW trending swell of the Kharga uplift and bounded at the south by the Oweinat-Bir Safsaf-Aswan uplift. These major tectonic units are controlled by fault structures trending in N-S, E-W, NE-SW, NW-SE, which cut the basement rocks and extend upward in the sedimentary cover. The maximum thickness of sandstone formations is recorded at west Oweinat, west Kurkur, southwest of Aswan, Gramashin, Dakhla oasis and some localities west of Sohag and Qena towns. At these localities the thickness ranges between 600 and 900 m. As this formation is the main water aquifer in the study area, therefore these localities are characterized by the presence of big amount of ground water. Accordingly, these areas must take the priority in the sustainable development programs of southern Egypt.

  5. The Iceland Deep Drilling Project, a 5 km Deep Drillhole Underway to Investigate Deep Geothermal Resources on the Mid-Atlantic Ridge.

    NASA Astrophysics Data System (ADS)

    Elders, W. A.; Fridleifsson, G. O.; Bird, D. K.; Pope, E. C.; Freedman, A. J.; Schiffmann, P.; Zierenberg, R. A.; Reed, M. H.; Palandri, J.

    2005-12-01

    The Iceland Deep Drilling Project (IDDP) is a long-term study of high-temperature hydrothermal systems on the Reykjanes Peninsula, where the Mid-Atlantic Ridge emerges on to the SW tip of Iceland. The IDDP is a collaborative effort, by a consortium of Icelandic power companies and the Icelandic government, to investigate if utilizing supercritical geothermal fluids would improve the economics of power production from geothermal fields. Over the next decade this will involve drilling a series of wells >4 km deep, to reach temperatures ~450°C. The deepest of these wells so far was completed at 3.1 km in February 2005. The rocks penetrated consist of Holocene basaltic lavas, subglacial hyaloclastites, marine sediments, submarine pillow basalts, and diabase dikes. In 2006, the IDDP will rotary drill and spot core this, or another candidate well, to 4.0 km, and in 2007, the IDDP will deepen the borehole from 4.0 km to 5.0 km, using continuous wireline coring. Such deep, hot wells present both technical challenges and opportunities for important scientific studies. For example, preliminary analyses of rock samples and fluids from the existing geothermal wells indicate that the shallow geothermal system is complex, as indicated by paragenetic relations and strong compositional zoning in calc-silicate minerals, such as epidote. Calculation of local equilibria between calc-silicates and calcite suggests that the CO2 content of the geothermal fluids increased during the evolution of this geothermal system. Zoned hydrothermal amphiboles at 3.1 km depth include tschermakitic hornblende (~13 wt. % Al2O3), suggesting temperatures in the upper 300°C range. Similarly, analyses of hydrogen isotopic ratios of epidotes and amphiboles currently underway indicate that meteoric water has mixed with seawater during the evolution of the Reykjanes geothermal system. The Reykjanes Peninsula is a superb location for scientific investigations of the deeper levels of a high enthalpy geothermal resource. Coring below 4.0 km is designed to penetrate into supercritical fluids which couple black smoker hydrothermal systems with their magmatic heat sources. Supercritical fluids have greatly enhanced rates of mass transfer and chemical reaction. Such environments have never before been available for comprehensive direct study and sampling. These investigations will be a very important contribution to global science and have clear connections to the studies of ridge-hotspot interactions by the Integrated Ocean Drilling Program. The broader implications of the IDDP are twofold; scientifically it will permit a quantum leap in our understanding of active hydrothermal processes that are important on a global scale, and secondly, if the industrial aims are successful, the resulting technology could have a major impact on improving the economics of high-temperature geothermal resources worldwide. The IDDP has welcomed participation by an international group of scientists that will investigate and test models of the coupling of hydrothermal and magmatic processes. The status of the project is reported at http://www.iddp.is.

  6. Thickness variation of the sedimentary cover in the South Western Desert of Egypt as deduced from Bouguer gravity and drill-hole data using neural network method

    NASA Astrophysics Data System (ADS)

    Abdel Zaher, M.; Senosy, M. M.; Youssef, M. M.; Ehara, S.

    2009-06-01

    The Bouguer anomaly map of scale 1:500,000 and the lithological logs of more than 120 deep wells distributed in the Southern part of Western Desert of Egypt were used to determine the thickness of the sedimentary cover containing the main sandstone water formation. The predominant structures affecting both the basement rock and the sedimentary cover were also studied. Gravity stripping approach was applied to separate density anomalies within the sedimentary fill from the influence of deeper levels in the crystalline crust. The study indicated that the surface of the basement rock is highly rugged and mostly controlled by structures causing variation of the sedimentary cover thickness from location to other all over the area. Isopach maps were constructed based on the Artificial Neural Network (ANN) model which is considered a best method for that operation. The maximum thickness of sandstone formations is recorded at west Oweinat, southwest of Aswan, Dakhla oasis and west of Qena town. As this formation is the main water aquifer in the study area, therefore these locations are characterized by the presence of huge amount of ground water. Accordingly, these areas must be taking the priority in the programs of sustainable development in southern Egypt.

  7. On the origin of mixed-layered clay minerals from the San Andreas Fault at 2.5-3 km vertical depth (SAFOD drillhole at Parkfield, California)

    NASA Astrophysics Data System (ADS)

    Schleicher, A. M.; Warr, L. N.; van der Pluijm, B. A.

    2009-02-01

    A detailed mineralogical study is presented of the matrix of mudrocks sampled from spot coring at three key locations along the San Andreas Fault Observatory at depth (SAFOD) drill hole. The characteristics of authigenic illite-smectite (I-S) and chlorite-smectite (C-S) mixed-layer mineral clays indicate a deep diagenetic origin. A randomly ordered I-S mineral with ca. 20-25% smectite layers is one of the dominant authigenic clay species across the San Andreas Fault zone (sampled at 3,066 and 3,436 m measured depths/MD), whereas an authigenic illite with ca. 2-5% smectite layers is the dominant phase beneath the fault (sampled at 3,992 m MD). The most smectite-rich mixed-layered assemblage with the highest water content occurs in the actively deforming creep zone at ca. 3,300-3,353 m (true vertical depth of ca. 2.7 km), with I-S (70:30) and C-S (50:50). The matrix of all mudrock samples show extensive quartz and feldspar (both plagioclase and K-feldspar) dissolution associated with the crystallization of pore-filling clay minerals. However, the effect of rock deformation in the matrix appears only minor, with weak flattening fabrics defined largely by kinked and fractured mica grains. Adopting available kinetic models for the crystallization of I-S in burial sedimentary environments and the current borehole depths and thermal structure, the conditions and timing of I-S growth can be evaluated. Assuming a typical K+ concentration of 100-200 ppm for sedimentary brines, a present-day geothermal gradient of 35°C/km and a borehole temperature of ca. 112°C for the sampled depths, most of the I-S minerals can be predicted to have formed over the last 4-11 Ma and are probably still in equilibrium with circulating fluids. The exception to this simple burial pattern is the occurrence of the mixed layered phases with higher smectite content than predicted by the burial model. These minerals, which characterize the actively creeping section of the fault and local thin film clay coating on polished brittle slip surfaces, can be explained by the influence of either cooler fluids circulating along this segment of the fault or the flow of K+-depleted brines.

  8. Clay Neomineralization and its Role in a Weak San Andreas Fault: new Insights From the SAFOD Drillhole in Parkfield/California

    NASA Astrophysics Data System (ADS)

    Schleicher, A. M.; van der Pluijm, B. A.; Warr, L. N.

    2007-12-01

    Neomineralization in fault zones and its influence on deformation and shear strength has been suggested as a possible explanation for a weak fault behavior. However, studies often lack the localization and characterization of the minerals along the slip surfaces, which is crucial for understanding the role of mineralization in fault zone processes. In this study, a detailed examination of illite minerals has been conducted from three sedimentary core samples of the SAFOD drill hole (3066m, 3436m and 3992m), showing different degrees of shearing and deformation. Based on X-ray diffraction and electron microscopy (SEM, TEM), we measured the crystal structure and fabric, as well as the shape and size of illite, their chemical composition, water content and polytypes. All samples contain detrital quartz, feldspar, chlorite, muscovite and biotite, with authigenic illite, illite-smectite (I-S), chlorite-smectite and smectite. The I-S phase at 3066m contains ca 75% of illite with a long-range ordering (R¡Ý3), the I-S at 3436m consists of ca 70% illite with randomly ordered smectite layers (R0), and illite at 3992m reveal thicker crystals without distinct smectite interlayers. The chemical composition ranges from a muscovitic composition (~1.0pu) at 3992m to depleted interlayer values of 0.5pu at 3436m. However, all illite phases show mixtures of 2M1 and 1M polytypes, with the coarse-grained (~150nm thick) pseudohexagonal 2M1 phase dominating and the very fine grained (10-15nm thick) 1M illite occurring as fibrous or flaky pore-fillings. The fine grained mineral phases were likely formed during the circulation of aqueous fluids along permeable fractures and veins by dissolution-precipitation reactions, partly at the expense of the detrital packets. Based on CALCMIX modeling, the clays contain different amounts of interlayer water with the highest values recorded at 3436m. Also heat flow analyses indicate the highest volatiles content at 3436m (6.5% total volatiles with 2% interlayer water), and the lowest volatiles content (2.7% with 0% interlayer water) at 3992m. The timing of illite growth in the matrix is considered to be coeval or older than the growth reported along open fractures, which are notably smectite rich and are an indication of more extensive dissolution associated with enhanced fluid flow. The localization of clay indicates that these phyllosilicates may dominate the fault behavior at shallow depth, as it is the dominant phase in these fault rocks.

  9. Examining the feasibility of modeling the subsurface structure of two volcanic units in drill-holes UE18r and ER-EC-2a using existing magnetic data

    USGS Publications Warehouse

    Phelps, G.A.

    2010-01-01

    The magnetic properties of two volcanic units encountered in two drill holes, ER-EC-2a and UE18r, located in the vicinity of the Nevada Test Site, were investigated to determine if the units were significantly more magnetic than overlying units and, thus, detectable by using aeromagnetic data. Magnetic-susceptibility measurements were made on cuttings from the drill holes and were combined with published data on remanent magnetism to generate two-dimensional magnetic models, based on an interpreted geologic cross-section. The resulting magnetic anomaly calculated from the models was compared with the observed aeromagnetic anomaly and was found to differ significantly from it. Furthermore, the calculated magnetic anomalies were found to be relatively insensitive to changes in the two units of interest.

  10. Drill-hole data, drill-site geology, and geochemical data from the study of Precambrian uraniferous conglomerates of the Medicine Bow Mountains and Sierra Madre of southeastern Wyoming

    SciTech Connect

    Karlstrom, K.E.; Houston, R.S.; Schmidt, T.G.; Inlow, D.; Flurkey, A.J.; Kratochvil, A.L.; Coolidge, C.M.; Sever, C.K.; Quimby, W.F.

    1981-02-01

    This volume is presented as a companion to Volume 1: The Geology and Uranium Potential of Precambrian Conglomerates in the Medicine Bow Mountains and Sierra Madre of Southeastern Wyoming; and to Volume 3: Uranium Assessment for Precambrian Pebble Conglomerates in Southeastern Wyoming. Volume 1 summarized the geologic setting and geologic and geochemical characteristics of uranium-bearing conglomerates in Precambrian metasedimentary rocks of southeastern Wyoming. Volume 3 is a geostatistical resource estimate of U and Th in quartz-pebble conglomerates. This volume contains supporting geochemical data, lithologic logs from 48 drill holes in Precambrian rocks of the Medicine Bow Mountains and Sierra Madre, and drill site geologic maps and cross-sections from most of the holes.

  11. Evaluation of the thermomechanical behavior about a waste container/sleeve in salt

    SciTech Connect

    Waldman, H.

    1983-04-01

    This report deals with the very-near-field aspects of waste disposal in conceptual repositories within a salt medium and concentrates on the thermomechanical behavior around a drillhole containing a nuclear waste canister. Specifically, this includes an investigation of: (1) the expected closure of an unlined drillhole, and (2) the pressure buildup on a protective sleeve initially in direct contact with the drillhole wall. The results of the current study based on the disposal of unreprocessed spent fuel (SF) and a review of previous near-field studies based on the emplacement of high-level waste (HLW) are included. The current SF study uses a thermo/viscoelastic mechanical model involving an empirical creep law. Previous HLW studies were based on either a thermoelastic/plastic mechanical model or a thermo/viscoelastic model that did not include temperature dependence in the creep law. Several repository designs were considered with drillholes ranging from 50.8 cm to 61.0 cm in diameter. The thermomechanical behavior was modeled over a 25-year period after which retrieval was not expected to be a major concern. Sleeve pressures for the lined drillhole did not exceed 21 MPa and would not warrant specially designed sleeves. Unlined drillholes 53.3 cm in diameter can accommodate HLW packages up to 45 cm in diameter for at least 10 years while a 61.0-cm-diameter drillhole will accommodate SF waste packages up to 43 cm in diameter for at least 25 years.

  12. Drilling Predation on Serpulid Polychaetes (Ditrupa arietina) from the Pliocene of the Cope Basin, Murcia Region, Southeastern Spain

    PubMed Central

    Martinell, Jordi; Kowalewski, Michał; Domènech, Rosa

    2012-01-01

    We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ∼5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 to 13.4 mm in length and displayed allometric growth patterns, with larger specimens being relatively slimmer. Drilled Ditrupa tubes were observed in all samples. Drillholes, identified as Oichnus paraboloides, were characterized by circular to elliptical outline (drillhole eccentricity increased with its diameter), parabolic vertical profile, outer diameter larger than inner diameter, penetration of one tube wall only, narrow range of drill-hole sizes, and non-random (anterior) distribution of drillholes. A total of 233 drilled specimens were identified, with drilling frequencies varying across horizons from 2.7% to 21% (3.9% for pooled data). Many tube fragments were broken across a drillhole suggesting that the reported frequencies are conservative and that biologically-facilitated (drill-hole induced) fragmentation hampers fossil preservation of complete serpulid tubes. No failed or repaired holes were observed. Multiple complete drillholes were present (3.9%). Drilled specimens were significantly smaller than undrilled specimens and tube length and drill-hole diameter were weakly correlated. The results suggest that drillholes were produced by a size-selective, site-stereotypic predatory organism of unknown affinity. The qualitative and quantitative patterns reported here are mostly consistent with previous reports on recent and fossil Ditrupa and reveal parallels with drilling patterns documented for scaphopod mollusks, a group that is ecologically and morphologically similar to Ditrupa. Consistent with previous studies, the results suggest that free-dwelling serpulid

  13. Preliminary report on some factors affecting shotpoint efficiency

    USGS Publications Warehouse

    Jackson, W.H.; Healy, J.H.

    1964-01-01

    A study of first-arrival amplitudes from 6 water shotpoints and 7 drill-hole shotpoints in parts of central and western United States indicate a variation of over 100 to 1 between the best and poorest shotpoints. Water shotpoints are, in general, superior to drill-hole shotpoints; however, one drill-hole shotpoint produced higher signal amplitudes than more than half of the water shotpoints. Signal amplitudes from drill-hole shotpoints varied by a factor of over 20. Saturated clay shooting medium appears to be the best shooting medium. Amplitudes from water shotpoints varied by a factor of about 10. Signal amplitude increases, in general, with water depth for bottom shots.

  14. Mineral and Lithology Mapping of Drill Core Pulps Using Visible and Infrared Spectrometry

    SciTech Connect

    Taylor, G. R.

    2000-12-15

    A novel approach for using field spectrometry for determining both the mineralogy and the lithology of drill core pulps (powders) is developed and evaluated. The methodology is developed using material from a single drillhole through a mineralized sequence of rocks from central New South Wales. Mineral library spectra are used in linear unmixing routines to determine the mineral abundances in drill core pulps that represent between 1 m and 3 m of core. Comparison with X-Ray Diffraction (XRD) analyses shows that for most major constituents, spectrometry provides an estimate of quantitative mineralogy that is as reliable as that provided by XRD. Confusion between the absorption features of calcite and those of chlorite causes the calcite contents determined by spectrometry to be unreliable. Convex geometry is used to recognize the spectra of those samples that are extreme and are representative of unique lithologies. Linear unmixing is used to determine the abundance of these lithologies in each drillhole sample and these abundances are used to interpret the geology of the drillhole. The interpreted geology agrees well with conventional drillhole logs of the visible geology and photographs of the split core. The methods developed provide a quick and cost-effective way of determining the lithology and alteration mineralogy of drill core pulps.

  15. A Placer-Gold Evaluation Exercise.

    ERIC Educational Resources Information Center

    Tunley, A. Tom

    1984-01-01

    A laboratory exercise allowing students to use drillhole data to simulate the process of locating a placer gold paystreak is presented. As part of the activity students arithmetically compute the value of their gold, mining costs, and personal profits or losses, and decide on development plans for the claim. (BC)

  16. Upper proterozoic geology and hydrocarbon prospects, Metropolitan Moscow District

    SciTech Connect

    Kuz`menko, Yu.T.; Kuklinskii, A.Ya.; Pimenov, Yu.G.

    1994-09-01

    New data on the geological makeup of the Teplostansk Graben of the Moscow Aulacogen deals with lithological-geochemical rock characteristics in deep drillholes in the Moscow area and about the enclosed bituminoids. Hydrocarbon prospects of the Upper Proterozoic beds in the graben have been evaluated.

  17. Results of site validation experiments. Volume II. Supporting documents 5 through 14

    SciTech Connect

    Not Available

    1983-01-01

    Volume II contains the following supporting documents: Summary of Geologic Mapping of Underground Investigations; Logging of Vertical Coreholes - ''Double Box'' Area and Exploratory Drift; WIPP High Precision Gravity Survey; Basic Data Reports for Drillholes, Brine Content of Facility Internal Strata; Mineralogical Content of Facility Interval Strata; Location and Characterization of Interbedded Materials; Characterization of Aquifers at Shaft Locations; and Permeability of Facility Interval Strate.

  18. 30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... underground openings: General requirements. Each exploration hole, other drillhole or borehole, shaft, well..., fish and wildlife, and machinery in the permit area and adjacent area. Each exploration hole, drill... be permanently closed, unless approved for water monitoring or otherwise managed in a manner...

  19. Geology of Medicine Lake Volcano, Northern California Cascade Range

    USGS Publications Warehouse

    Donnelly-Nolan, Julie

    1990-01-01

    Medicine Lake volcano (MLV) is located in an E-W extensional environment on the Modoc Plateau just east of the main arc of the Cascades. It consists mainly of mafic lavas, although drillhole data indicate that a larger volume of rhyolite is present than is indicated by surface mapping. The most recent eruption was rhyolitic and occurred about 900 years ago. At least seventeen eruptions have occurred since 12,000 years ago, or between 1 and 2 eruptions per century on average, although activity appears to be strongly episodic. The calculated eruptive rate is about 0.6 km3 per thousand years during the entire history of the volcano. Drillhole data indicate that the plateau surface underlying the volcano has been downwarped by 0.5 km under the center of MLV. The volcano may be even larger than the estimated 600 km3, already the largest volcano by volume in the Cascades.

  20. How one engineer and computer workstation design a surface mine. [New Mexico

    SciTech Connect

    Chironis, N.P.

    1984-04-01

    Engineers at the new Lee Ranch coal mine near Grants, New Mexico, decided to use an interactive computer and workstation, and a mine-planning programme capable of handling day-to-day production. Scheduling and producing necessary plans, maps, and other graphics: the programme called MINEMAP can deal also with drill-hole data and stripping ratios. Teamed with MINEMAP is a computerized drafting and plotting system called DISSPLA.

  1. Taphonomic pathways and environmental differentiation based on the clypeasteroid echinoid Echinocyamus

    NASA Astrophysics Data System (ADS)

    Grun, Tobias; Nebelsick, James

    2015-04-01

    Taphonomic pathways that dictate the preservation of skeletal components differ along environmental gradients. Understanding preservation potentials within different habitats are key factors in reconstructing paleoenvironments. Actualistic studies allow for direct correlation of taphonomic features with environmental parameters serving as models for fossil analogies. This study concentrates on a single genus of clypeasteroid echinoids thus alleviating the influence of differential skeletal architectures on taphonomic pathways. The goal of this study is to gain detailed information on the alteration and preservation of recent examples and their variations with respect to environmental conditions with the goal of applying this knowledge to fossil populations. Numerous tests of the minute clypeasteroid echinoid Echinocyamus pusillus were collected from the Island of Giglio (Mediterranean Sea) from various depths and environments. The tests were analyzed for taphonomic alteration including the abrasion of the (1) tubercles, (2) stereom and (3) genital and ambulacral pores. The preservation of the (4) ambitus and the (5) test were also analyzes as well as the degree of (5) encrustation and (6) fragmentation. When drillholes of predatory gastropods were present, these were analyzed for the (7) drillhole outline and (8) cross-section. These features were analyzed both qualitatively and quantitatively and subjected to statistical analysis. Results indicate that most tests show a rather good preservation with individuals from sheltered areas featuring a low grade of tubercle and stereom abrasion. Pores are mostly not affected and the encrustation rate is low. Areas with higher wave activities yield individuals which features higher abrasion grades. Pores are more often affected than in sheltered areas, while the encrustation rate is significantly lower. Drillholes are generally robust to abrasion, since almost all drillhole outlines and the concave cross-sections are well

  2. Application of a feedforward neural network in the search for kuroko deposits in the hokuroku district, Japan

    USGS Publications Warehouse

    Singer, D.A.; Kouda, R.

    1996-01-01

    A feedforward neural network with one hidden layer and five neurons was trained to recognize the distance to kuroko mineral deposits. Average amounts per hole of pyrite, sericite, and gypsum plus anhydrite as measured by X-rays in 69 drillholes were used in train the net. Drillholes near and between the Fukazawa, Furutobe, and Shakanai mines were used. The training data were selected carefully to represent well-explored areas where some confidence of the distance to ore was assured. A logarithmic transform was applied to remove the skewness of distance and each variable was scaled and centered by subtracting the median and dividing by the interquartile range. The learning algorithm of annealing plus conjugate gradients was used to minimise the mean squared error of the sealed distance to ore. The trained network then was applied to all of the 152 drillholes that had measured gypsum, sericite, and pyrite. A contour plot of the neural net predicted distance to ore shows fairly wide areas of 1 km or less to ore; each of the known deposit groups is within the 1 km contour. The high and htw distances on the margins of the contoured distance plot are in part the result of boundary effects of the contouring algorithm. For example, the short distances to ore predicted west of the Shakanai (Hanaoka) deposits are in basement. However, the short distances to ore predicted northeast of Furotobe, just off the figure, coincide with the location of the Nurukawa kuroko deposit and the Omaki deposit, south of the Shakanai-Hanaoka deposits, seems to be on an extension of short distance to ore contour, but is beyond the 3 km limit from drillholes. Also of interest are some areas only a few kilometers from the Fukazawa and Shakanai groups of deposits that are estimated to be many kilometers from ore, apparently reflecting the network's recognition of the extreme local variability of the geology near some deposits. 1996 International Association for Mathematical Geology.

  3. Element mobility studies of two drill-cores from the Götemar Granite (Kråkemåla test site), southeast Sweden

    USGS Publications Warehouse

    Smellie, John A.T.; Stuckless, John S.

    1985-01-01

    The pervasive alteration and the more recent mobilisation of U are evident to a depth of at least 600 m. The effects are most prevalent along major fracture zones and within the upper 250–300 m of one drill-hole where a high frequency of crush zones has been noted. Higher Fe oxidation ratios, higher Rb contents, lower U contents and correspondingly higher Th/U ratios, all characterise this zone.

  4. Uranium assessment for the Precambrian pebble conglomerates in southeastern Wyoming

    SciTech Connect

    Borgman, L.E.; Sever, C.; Quimby, W.F.; Andrew, M.E.; Karlstrom, K.E.; Houston, R.S.

    1981-03-01

    This volume is a geostatistical resource estimate of uranium and thorium in quartz-pebble conglomerates, and is a companion to Volume 1: The Geology and Uranium Potential to Precambrian Conglomerates in the Medicine Bow Mountains and Sierra Madre of Southeastern Wyoming; and to Volume 2: Drill-Hole Data, Drill-Site Geology, and Geochemical Data from the Study of Precambrian Uraniferous Conglomerates of the Medicine Bow Mountains and the Sierra Madre of Southeastern Wyoming.

  5. Using drill cutting separates to estimate the strength of narrow shear zones at SAFOD

    USGS Publications Warehouse

    Morrow, C.; Solum, J.; Tembe, S.; Lockner, D.; Wong, T.-F.

    2007-01-01

    A technique is presented for estimating frictional strength of narrow shear zones based on hand selection of drillhole cuttings separates. Tests were conducted on cuttings from the SAFOD scientific drillhole near Parkfield, California. Since cuttings are mixed with adjacent material as they travel up the drillhole, these fault-derived separates give a better representation of the frictional properties of narrow features than measurements from the bulk material alone. Cuttings from two shear zones (one an active trace of the San Andreas fault) contain a significant weight percent of clay-rich grains that exhibit deformation-induced slickensides. In addition, cuttings from the active SAF trace contain around 1% serpentine. Coefficients of friction for clay-rich and serpentine grains were 0.3-0.5 and 0.4-0.45, respectively. These values are around 0.12 lower than the friction coefficient of the corresponding bulk cuttings, providing an improved estimate of the frictional strength of the San Andreas fault. Copyright 2007 by the American Geophysical Union.

  6. Variable lag variography using k-means clustering

    NASA Astrophysics Data System (ADS)

    Kapageridis, I. K.

    2015-12-01

    Experimental variography in three dimensions based on drillhole data and current modelling software requires the selection of particular directions (azimuth and plunge) and a basic lag distance. Variogram points are then calculated on distances which are multiples of that basic lag. As samples rarely follow a regular grid, directional and distance tolerances are applied in order to have sufficient pairs to calculate reliable variogram points. This process is adequate when drillholes follow a drilling pattern (even if not an exactly regular grid) but can be time consuming and hard when the drilling pattern is irregular or when drillhole orientations vary considerably. Having all variogram points being calculated on multiples of a fixed lag, and the same tolerance being applied throughout the range of distances used, can be very restrictive and a reason for considerable time wasting or even failure to calculate an interpretable experimental variogram. The method discussed in this paper is using k-means clustering of sample pairs based on pair separation distance leading to a number of clusters each representing a different variogram point. This way, lag parameters are adjusted automatically to match the spatial distribution of sample locations and the resulting variogram is improved. Case studies are provided showing the benefits of this method over current fixed-lag experimental variogram calculation techniques.

  7. Seismic reflection structure of intracratonic palmyride fold-thrust belt and surrounding Arabian platform, Syria

    SciTech Connect

    McBride, J.H.; Barazangi, M.; Best, J. ); Al-Saad, D.; Sawaf, T.; Al-Otri, M.; Gebran, A. )

    1990-03-01

    Seismic reflection and drill-hole data from central Syria provide a detailed view of the subsurface structure (10-15 km depth) of the relatively little-studied intracratonic Palmyride fold and thrust belt. The data set, together with surface geologic mapping, constrains a structural/stratigraphic section spanning the northeast sector of the belt and the surrounding subprovinces of the Arabian platform. The seismic reflection and drill-hole data show Mesozoic stratigraphic sequences thickening abruptly into the Palmyrides from the adjacent, arched Paleozoic platforms Neogene (alpine) folding and thrusting of the Mesozoic basin, as documented on the seismic data, are sharply restricted to the narrow width of the belt ({approximately}100 km), in contrast to the relatively undeformed Phanerozoic strata of the platforms to the north and south. The seismic and drill-hole data support the hypothesis that the palmyrides began as a Permian-Triassic failed rift connected to the Levantine passive continental margin, which was inverted and complexly deformed by the interfering effects of Cenozoic movements along the Dead Sea transform fault system and the Turkish Bitlis convergent zone. The seismic data provide a first view into the extent and depth of the early basin formation and subsequent compressional deformation, and as such represent a necessary element for constraining reconstructions of northern Middle East plate motions. 20 figs.

  8. Electromagnetic detection of subsurface voids. Final report

    SciTech Connect

    Wilt, M.J.; Becker, A.

    1985-11-01

    This report presents the results of a time domain electromagnetic survey over a subsurface cavity near drillhole U2ck at the Nevada test site. The purpose of the survey was to test the sensitivity of the time domain method using maximum and minimum coupled coiled configurations for the detection of subsurface cavity. The survey was made with the Geonics EM-37 system deployed so that horizontal and vertical magnetic field sensors are positioned at the center of the transmitter loop. Measurements were made at 25 and 50 m intervals on N-S and E-W trending profiles over the drillhole. The purpose of the study was to map the subsurface cavity associated with drillhole U2ck. Initial results indicate significant horizontal field anomalies near ground zero. Some of the horizontal field profiles closely resemble scale model profiles for buried fractures presented by Becker and Dallal (1985). Because of the difference in the time scale, however, we cannot use those results to obtain quantitative information about the cavity.

  9. Geochemistry of Salado Formation brines recovered from the Waste Isolation Pilot Plant (WIPP) repository

    SciTech Connect

    Abitz, R.; Myers, J.; Drez, P.; Deal, D.

    1990-01-01

    Intergranular brines recovered from the repository horizon of the Waste Isolation Pilot Plant (WIPP) have major- and trace-element compositions that reflect seawater evaporation and diagenetic processes. Brines obtained from repository drill holes are heterogenous with respect to composition, but their compositional fields are distinct from those obtained from fluid inclusions in WIPP halite. The heterogeneity of brine compositions within the drill-hole population indicates a lack of mixing and fluid homogenization within the salt at the repository level. Compositional differences between intergranular (drill hole) and intragranular (fluid inclusions) brines is attributed to isolation of the latter from diagenetic fluids that were produced from dehydration reactions involving gypsum and clay minerals. Modeling of brine-rock equilibria indicates that equilibration with evaporite minerals controls the concentrations of major elements in the brine. Drill-hole brines are in equilibrium with the observed repository minerals halite, anhydrite, magnesite, polyhalite and quartz. The equilibrium model supports the derivation of drill-hole brines from near-field fluid, rather than large-scale vertical migration of fluids from the overlying Rustler or underlying Castile Formations. 13 refs., 6 figs., 6 tabs.

  10. Comparison of sea-ice thickness measurements under summer and winter conditions in the Arctic using a small electromagnetic induction device

    SciTech Connect

    Haas, C.; Eicken, H.; Miller, H.; Gerland, S.

    1997-05-01

    Drillhole-determined sea-ice thickness was compared with values derived remotely using a portable small-offset loop-loop steady state electromagnetic (EM) induction device during expeditions to Fram Strait and the Siberian Arctic, under typical winter and summer conditions. Simple empirical transformation equations are derived to convert measured apparent conductivity into ice thickness. Despite the extreme seasonal differences in sea-ice properties as revealed by ice core analysis, the transformation equations vary little for winter and summer. Thus, the EM induction technique operated on the ice surface in the horizontal dipole mode yields accurate results within 5 to 10% of the drillhole determined thickness over level ice in both seasons. The robustness of the induction method with respect to seasonal extremes is attributed to the low salinity of brine or meltwater filling the extensive pore space in summer. Thus, the average bulk ice conductivity for summer multiyear sea ice derived according to Archie`s law amounts to 23 mS/m compared to 3 mS/m for winter conditions. These mean conductivities cause only minor differences in the EM response, as is shown by means of 1-D modeling. However, under summer conditions the range of ice conductivities is wider. Along with the widespread occurrence of surface melt ponds and freshwater lenses underneath the ice, this causes greater scatter in the apparent conductivity/ice thickness relation. This can result in higher deviations between EM-derived and drillhole determined thicknesses in summer than in winter.

  11. Imaging of unconformity related uranium ore zones by crosshole ERT

    NASA Astrophysics Data System (ADS)

    Yi, M.; Kim, C.; Son, J.

    2011-12-01

    For the exploration of unconformity type uranium deposits in the Athabasca basin, Canada, electrical resistiivty survey is commonly used to define graphtic conductors in the basement. The method, however, can not provide enough resolution since the exploration target is seated in depth greater than 300 m while the width is less than 50 m. To overcome this inherent problem and introduce new exploration technology, we applied the crosshole ERT(Electrical Resistivity Tomography) technology in the Athabasca basin. Since the drillholes are not vertical and randomly oriented, 3D ERT inversion algorithm, accommodating arbitray electrode locations, was used to reconstruct 2D surbsurface resistivity image. For the 2D inversion in 3D inversion code, subsurface was assumed to be two-dimensional. We also applied the full 3D inversion to the field data set from several drillholes. In the ERT images, we could observe the graphitic pelite zone with very low resistivity which is our exploration target. By defining the accurate location of graphtic conductor, we could understand the basic setting of the site. Moreover, in the 3D ERT image, we could define anomalous zone in 3D space which can be related to the uranium target. By this introductory ERT survey, we could show that ERT can be used as a new geophysical exploration method in the Athabasca basin. In the current exploration procedure, barren drillholes are abandoned and further geophysical surveys using thes holes are rare in most cases. Since ERT technique can provide very high resolution image of the subsurface, we can have more detailed information to design the drilling program and this can lead to the cost reduction of exploration program. We expect crosshole ERT will become a standard geophysical methods in the exploration projects in the Athabasca basin.

  12. Blake Plateau: control of Miocene sedimentation patterns by large- scale shifts of the Gulf Stream axis.

    USGS Publications Warehouse

    Pinet, P.R.; Popenoe, P.

    1982-01-01

    The distribution of buried channel networks within Cenozoic sequences of the Blake Plateau and their correlation with global sea-level oscillations indicate that the Gulf Stream axis shifted landward against the Florida-Hatteras Slope during sea-level highstands and seaward across the central Blake Plateau during sea-level lowstands. A sedimentation model incorporating axial shifts of the Gulf Stream successfully predicts the Miocene stratigraphy of the Florida-Hatteras Slope and Blake Plateau as defined by seismic and drill-hole data. -Authors Cenozoic sequences Blake Plateau sea level oscillations North Atlantic

  13. Thermal waters of the Yemen Arab Republic

    SciTech Connect

    Dowgiallo, J.

    1986-01-01

    Thermal waters (30-61/sup 0/C) occur in springs and shallow drill-holes (max. 300 m) in several areas of the Yemen Arab Republic. Their mineral content is generally low ( < 1000-2000 ppm TDS) except for waters with high CO/sub 2/ content and those directly influenced by the evaporitic Baid formation (Tertiary) in the Western Lowlands along the Red Sea. The temperature anomalies occur in areas of Quaternary basaltic volcanism (Aden formation) and in fault zones connected with the eastern margin of the Red Sea graben. In the latter zones radiogenic heat may be contributed by Tertiary granitic intrusions.

  14. Exceptionally well-preserved early Oligocene diatoms from glacial sediments of Prydz Bay, East Antarctica

    USGS Publications Warehouse

    Barron, J.A.; Mahood, A.D.

    1993-01-01

    An exceptionally well-preserved early Oligocene diatom assemblage is documented and illustrated from the internal sediment of a gastropod shell, which was collected from glacial sedments recovered at ODP Site 739, Prydz Bay, Antarctica. The diatoms were deposited between 35.9 and 34.8 Ma according to diatom and calcareous nannofossil stratigraphy, apparently soon after a period of major ice sheet advance across the Prydz Bay continental shelf. The diatom assemblage is neritic in character, but it can readily be correlated with open ocean assemblages from the Southern Ocean as well as with similar material recovered from the CIROS-1 drillhole in the Ross Sea. -Authors

  15. Mechanical anisotropy of the Yucca Mountain tuffs

    SciTech Connect

    Price, R.H.; Boyd, P.J.; Martin, R.J.; Haupt, R.W.; Noel, J.S.

    1991-12-31

    Three series of measurements were performed on oriented cores of several Yucca Mountain tuffs to determine the importance of mechanical anisotropy in the intact rock. Outcrop and drillhole samples were tested for acoustic velocities, linear compressibilities, and strengths in different orientations. The present data sets are preliminary, but suggest the tuffs are transversely anisotropic for these mechanical properties. The planar fabric that produces the anisotropy is believed to be predominantly the result of the preferred orientation of shards and pumice fragments. The potential of significant anisotropy has direct relevance to the formulation of constitutive formulation and the analyses of an underground opening within the Yucca Mountain.

  16. Uniaxial compression test series on Bullfrog Tuff

    SciTech Connect

    Price, R H; Jones, A K; Nimick, K G

    1982-04-01

    Nineteen uniaxial compressive experiments were performed on samples of the Bullfrog Member of the Crater Flat Tuff, obtained from drillhole USW-G1 at Yucca Mountain on the Nevada Test Site. The water saturated samples were deformed at a nominal strain rate of 10{sup -5} sec{sup -1}, atmospheric pressure and room temperature. Resultant unconfined compressive strengths, axial strains to failure, Young`s moduli and Poisson`s ratios ranged from 4.63 to 153. MPa, .0028 to .0058, 2.03 to 28.9 GPa and .08 to .16, respectively.

  17. Thickness of Cenozoic deposits of Yucca Flat inferred from gravity data, Nevada Test Site, Nevada

    SciTech Connect

    Jachens, R.C.; Langenheim, V.E.; Phelps, G.A.

    1999-05-25

    The basin-basement contact for Yucca Flat was modeled using isostatic gravity data, a linear density-depth function for the basin deposits, and drill-hole constraints to produce a digital database of both the depth to basement and gravitational anomaly associated with the basement rocks. The model predicts a depth of roughly 2,500 m in the deepest, southern part of the basin. The model shows offsets in the basement rocks along both the Carpetbag and Yucca faults. The basement rocks of Yucca Flat have a higher gravity anomaly west of the N-S trending Carpetbag fault, suggesting higher density rocks on the west side of the valley.

  18. Fluid-inclusion evidence for past temperature fluctuations in the Kilauea East Rift Zone geothermal area, Hawaii

    USGS Publications Warehouse

    Bargar, K.E.; Keith, T.E.C.; Trusdell, F.A.

    1995-01-01

    Heating and freezing data were obtained for fluid inclusions in hydrothermal quartz, calcite, and anhydrite from several depths in three scientific observation holes drilled along the lower East Rift Zone of Kilauea volcano, Hawaii. Comparison of measured drill-hole temperatures with fluid-inclusion homogenization-temperature (Th) data indicates that only about 15% of the fluid inclusions could have formed under the present thermal conditions. The majority of fluid inclusions studied must have formed during one or more times in the past when temperatures fluctuated in response to the emplacement of nearby dikes and their subsequent cooling. -from Authors

  19. Definition imaging of an orebody with the radio imaging method (RIM)

    SciTech Connect

    Stolarczyk, L.G. )

    1992-10-01

    Waste rock dilution is an economic concern in the planning and design of mining methods for mineralized ore zones. Diamond core drilling and mineralogical examination of core are routinely used to determine the general shape of the ore body. Drilling on closer centers enhances the definition of the mineralization and oregrade across the orebody. In a practical sense, drilling time and cost limit definition. Crosshole scanning between drillholes with the radio imaging method (RIM) has been used to map changes in mineralization in the rock mass. The magnitude and phase of the RIM radio wave depend on the electrical conductivity of the rock mass. The conductivity strongly depends on the percent mineralization. Since the attenuation rate and phase constants of the radio wave are proportional to the one half power of conductivity, the measured crosshole radio wave data can be processed in a tomography algorithm to reconstruct images (map the change in conductivity (mineralization)). The tomography image enhances definition in the orebody while reducing the number of drillholes. This paper compares reconstructed images of the radio wave propagation constants to percent mineralization in the ore body.

  20. Pollution par les nitrates des eaux souterraines du bassin d'Essaouira (Maroc)

    NASA Astrophysics Data System (ADS)

    Laftouhi, Nour-Eddine; Vanclooster, Marnik; Jalal, Mohammed; Witam, Omar; Aboufirassi, Mohamed; Bahir, Mohamed; Persoons, Étienne

    2003-03-01

    The Essaouira Basin (Morocco) contains a multi-layered aquifer situated in fractured and karstic materials from the Middle and Upper Cretaceous (the Cenomanian, Turonian and Senonian). Water percolates through the limestone and dolomite formations of the Turonian stage either through the marls and calcareous marls of the Cenomanian or through the calcareous marly materials of the Senonian. The aquifer system may be interconnected since the marl layer separating the Turonian, Cenomanian and Senonian aquifers is thin or intensively fractured. In that case, the water is transported through a network of fractures and stratification joints. This paper describes the extent of the nitrate pollution in the area and its origin. Most of the wells and drillholes located in the Kourimat perimeter are contaminated by nitrates with some concentrations over 400 mg l-1. Nitrate contamination is also observed in the surface water of the Qsob River, which constitutes the natural outlet of the multi-layered complex aquifer system. In this area, agriculture is more developed than in the rest of the Essaouira Basin. Diffuse pollution of the karstic groundwater body by agricultural fertiliser residues may therefore partially explain the observed nitrate pollution. However, point pollution around the wells, springs and drillholes from human wastewater, livestock faeces and the mineralisation of organic debris close to the Muslim cemeteries cannot be excluded.

  1. Preliminary results on the characterization of Cretaceous and lower Tertiary low-permeability (tight) gas-bearing rocks in the Wind River Basin, Wyoming

    SciTech Connect

    Fouch, T.D.; Keefer, W.R.; Finn, T.M.

    1993-12-31

    The Wind River Basin is a structural and sedimentary basin in central Wyoming (Figure 1) that was created during the Laramide orogeny from Late Cretaceous through Eocene time. The objectives of the Wind River Basin tight gas sandstone project are to define the limits of the tight gas accumulation in the basin and to estimate in-place and recoverable gas resources. The approximate limits of the tight gas accumulation are defined from available drillhole information. Geologic parameters, which controlled the development of the accumulation, are studied in order to better understand the origins of tight gas accumulations, and to predict the limits of the accumulation in areas where little drillhole information is available. The architecture of sandstone reservoirs are studied in outcrop to predict production characteristics of similar reservoirs within the tight gas accumulation. Core and cuttings are used to determine thermal maturities, quality of source rocks, and diagenetic histories. Our work thus far has concentrated in the Wind River Indian Reservation in the western part of the basin.

  2. The Silent Canyon caldera: a three-dimensional model as part of a Pahute Mesa-Oasis Valley, Nevada, hydrogeologic model

    USGS Publications Warehouse

    McKee, Edwin H.; Phelps, Geoffery A.; Mankinen, Edward A.

    2001-01-01

    A 3-dimensional caldera model based on gravity inversion, drill-hole data, and geologic mapping offers the framework for a hydrogeologic evaluation of the Silent Canyon caldera in the central part of Pahute Mesa, Nevada. It has been recognized for several decades that the central part of Pahute Mesa is the site of a buried caldera called the Silent Canyon caldera. Conceptually, the structural framework of the Silent Canyon caldera is based on the idea of collapse of the caldera roof over a shallow magma chamber to form a structural basin following violent volcanic eruptions. Calderas are common in certain volcanic regions of the world, and most well-exposed calderas are broadly similar to each other, particularly the arcuate or circular shape of their collapse depression. There are other reasons for modeling the Silent Canyon caldera as a circular feature in addition to knowledge that calderas throughout the world are generally circular features. The Silent Canyon caldera is the site of one of the largest gravity lows in the Western United States, indicating a thick accumulation of low-density rocks such as lavas and tuffs—a fact confirmed by drilling on Pahute Mesa. This gravity low is bowl-shaped, and the uppermost volcanic units on Pahute Mesa form a circular outcrop pattern of inward-dipping tuff interpreted to be the result of their filling the upper part of the bowl-shaped depression. Together, these features are consistent with, and indicative of, a circular collapse structural model for the Silent Canyon caldera. The collapse depression of the Silent Canyon caldera, bounded by arcuate faults, is filled with as much as 6 km (19,800 ft) of volcanic and sedimentary rocks that are considerably less dense than the underlying and surrounding basement rocks. The boundary surface between less dense caldera fill and more dense basement is modeled as the caldera ring fault. Rocks in the upper part of the caldera fill are penetrated by drilling, and the drill-hole

  3. Heat Flow of the Norwegian Continental Shelf

    NASA Astrophysics Data System (ADS)

    Pascal, C.

    2015-12-01

    Terrestrial heat flow determination is of prime interest for oil industry because it impacts directly maturation histories and economic potential of oil fields. Published systematic heat flow determinations from major oil provinces are however seldom. Robust heat flow determinations in drillholes require logging of undisturbed temperatures and intensive sampling of core material for petrophysical measurements. Temperature logging in exploration drillholes is traditionally conducted during drill breaks or shortly after drilling, resulting in temperatures severely disturbed by mud circulation and coring is restricted to selected intervals. Alternatively, test temperatures, information from electric logs and lithological descriptions of drill cuttings can be used to overcome these limitations. The present contribution introduces new heat flow determinations based on 63 exploration drillholes from the Norwegian North Sea, the Mid Norway Margin and the Barents Shelf. Our analyses are based on released DST temperatures, precise lithological descriptions of drill cuttings, previously measured rock matrix thermal conductivities and established porosity laws. For the sake of comparison, we carefully review previous heat flow studies carried out both onshore and offshore Norway. Our results suggest median heat flow values of 64 mW/m2, 65 mW/m2 and 72 mW/m2 for the North Sea, the Mid Norway Margin (mainly the Trøndelag Platform) and the SW Barents Shelf respectively. In detail, heat flow increases by ~ 10 mW/m2 from the southern Norwegian North Sea towards the Mid Norway Margin. This result appears to be in very good agreement with seismic tomographic studies suggesting northward thinning of the underlying mantle lithosphere. Our results together with published marine heat flow data from the Mid Norway Margin suggest a gradual decrease in heat flow levels from both the North Sea and the Trøndelag Platform towards the centres of the deep Møre and Vøring basins. This latter

  4. Heat flow of the Norwegian continental shelf

    NASA Astrophysics Data System (ADS)

    Pascal, Christophe

    2015-04-01

    Terrestrial heat flow influences a large collection of geological processes. Its determination is a requirement to assess the economic potential of deep sedimentary basins. Published heat flow calculations from e.g. major oil provinces are however seldom. Robust heat flow determinations in drillholes require logging of undisturbed temperatures and intensive sampling of core material for petrophysical measurements. Temperature logging in exploration drillholes is traditionally conducted during drill breaks or shortly after drilling, resulting in temperatures severely disturbed by mud circulation and coring is restricted to selected intervals. Alternatively, test temperatures, information from electric logs and lithological descriptions of drill cuttings can be used to overcome these limitations. The present contribution introduces new heat flow determinations based on 63 exploration drillholes from the Norwegian North Sea, the Mid Norway Margin and the Barents Shelf. Our analyses are based on released DST temperatures, precise lithological descriptions of drill cuttings, previously measured rock matrix thermal conductivities and established porosity laws. Our results suggest median heat flow values of 64 mW/m2, 65 mW/m2 and 72 mW/m2 for the North Sea, the Mid Norway Margin (mainly the Trøndelag Platform) and the SW Barents Shelf respectively. The Barents Shelf shows significantly high heat flow, suggesting lateral transfer of heat from the mantle of the adjacent young ocean. In detail, heat flow increases by ~ 10 mW/m2 from the southern Norwegian North Sea towards the Mid Norway Margin. This result appears to be in very good agreement with seismic tomographic studies suggesting northward thinning of the underlying mantle lithosphere. Our results together with published marine heat flow data from the Mid Norway Margin suggest a gradual decrease in heat flow levels from both the North Sea and the Trøndelag Platform towards the centres of the deep Møre and V

  5. Geology of the Rotorua geothermal system

    SciTech Connect

    Wood, C.P. )

    1992-04-01

    This paper discusses the Rotorua geothermal system located in the south part of Rotorua Caldera, which collapsed during and after the eruption of Mamaku Ignimbrite some 140 ka ago. Drillholes provide geological and hydrological information to 300 m depth. The Mamaku Ignimbrite aquifer has been drilled in the east and south of the field where it contains fluid at or near boiling point. The Ignimbrite drops from south to north across exposed and buried caldera collapse scarps. Rotorua City domes comprise a buried N-S ridge rising at either end to form north and south domes; both contain mostly sub-boiling water up to 190{degrees} C which flows laterally through the outer 40 m of permeably rhyolite as indicated by temperature data. The Fenton Park aquifer comprises sands and gravels in the shallow sedimentary sequence which contain hot water derived possibly from Whakarewarewa, the south dome or the Rotoatamaheke Fault.

  6. Thermal regimes of major volcanic centers: magnetotelluric constraints

    SciTech Connect

    Hermance, J.F.

    1987-11-13

    The focus of activity at this laboratory is on applying natural electromagnetic methods along with other geophysical techniques to studying the dynamical processes and thermal regimes associated with centers of major volcanic activity. We are presently emphasizing studies of the Long Valley/Mono Craters Volcanic Complex, the Cascades Volcanic Belt, and the Valles Caldera. This work addresses questions regarding geothermal energy, chemical transport of minerals in the crust, emplacement of economic ore deposits, and optimal siting of drill-holes for scientific purposes. In addition, since much of our work is performed in the intermontane sedimentary basins of the western US (along with testing our field-system in some of the graben structures in the Northeast), there is an application of these studies to developing exploration and interpretational strategies for detecting and delineating structures associated with hydrocarbon reserves.

  7. Selected stratigraphic data for drill holes located in Frenchman Flat, Nevada Test Site. Rev. 1

    SciTech Connect

    Drellack, S.L. Jr.

    1997-02-01

    Stratigraphic data are presented in tabular form for 72 holes drilled in Frenchman Flat, Nevada Test Site, between 1950 and 1993. Three pairs of data presentations are included for each hole: depth to formation tops, formation thicknesses, and formation elevations are presented in both field (English) and metric units. Also included for each hole, where available, are various construction data (hole depth, hole diameter, surface location coordinates) and certain information of hydrogeologic significance (depth to water level, top of zeolitization). The event name is given for holes associated with a particular nuclear test. An extensive set of footnotes is included, which indicates data sources and provides other information. The body of the report describes the stratigraphic setting of Frenchman Flat, gives drill-hole naming conventions and database terminology, and provides other background and reference material.

  8. The permeability of gabbro in oceanic core complexes

    NASA Astrophysics Data System (ADS)

    Titarenko, S.; McCaig, A. M.

    2013-12-01

    In IODP Expedition 340T, a thermal gradient of about 100 °C km-1 was measured in IODP Hole U1309D (Blackman et al. 2013), located in 1.2 My old gabbroic crust in the footwall of an oceanic detachment fault in the Atlantis Massif, just west of the mid-Atlantic Ridge at 30° N. The gradient is linear below 748 mbsf, indicating an essentially conductive regime, and slightly concave above that depth, suggesting slow, long-term downward flow of seawater in surrounding rocks. The lack of any vigorous hydrothermal circulation at this site is remarkable considering that the serpentinite-hosted Lost City Hydrothermal Field (LCHF) is located only 5 km to the south, and has been venting highly alkaline fluids at 40-90 °C for at least the last 140,000 years. We have created a 2-D topographic model of the Atlantis Massif using a N-S profile through the LCHF and the drillhole location, and modelled hydrothermal circulation using Comsol Multiphysics. A maximum permeability of 10-17 m2 below 750 mbsf, and a basal heatflow of 0.22 Wm-1 are required at the drillhole location to suppress hydrothermal circulation and preserve the observed conductive thermal gradient at depth. The concave gradient above this depth can be closely fitted over long time periods with a layer 750 m thick of higher permeability, ~3x 10-14 m2. Fluid vents at the site of the LCHF and in a small knoll north of the drill hole, and enters the seafloor everywhere else, including the drillhole location. Model vent temperatures are only about 20 °C however, much less that at the LCHF. A model with a deeper permeable zone beneath the LCHF, with a permeability of 10-15 m2 or more, is required to match simultaneously both observed vent temperatures and the drillhole gradient. This deep permeable zone is hosted in serpentinite but is most likely related to active faulting related to the Atlantis Transform Fault, not lithological control on permeability. Data from the flanks of both fast and intermediate spreading

  9. Results of investigation at the Ahuachapan Geothermal Field, El Salvador

    SciTech Connect

    Fink, J.B. )

    1990-04-01

    The Ahuachapan Geothermal Field (AGF) is a 95 megawatt geothemal-sourced power-plant operated by the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) of El Salvador. During the past decade, as part of an effort to increase in situ thermal reserves in order to realize the full generation capacity of the AGF, extensive surface geophysical coverage has been obtained over the AGF and the prospective Chipilapa area to the east. The geophysical surveys were performed to determine physical property characteristics of the known reservoir and then to search for similar characteristics in the Chipilapa area. A secondary objective was to evaluate the surface recharge area in the highlands to the south of the AGF. The principal surface electrical geophysical methods used during this period were DC resistivity and magnetotellurics. Three available data sets have been reinterpreted using drillhole control to help form geophysical models of the area. The geophysical models are compared with the geologic interpretations.

  10. Bedrock geologic map of the Spring Valley, West Plains, and parts of the Piedmont and Poplar Bluff 30'x60' quadrangles, Missouri, including the upper Current River and Eleven Point River drainage basins

    USGS Publications Warehouse

    Weary, David J.; Harrison, Richard W.; Orndorff, Randall C.; Weems, Robert E.; Schindler, J. Stephen; Repetski, John E.; Pierce, Herbert A.

    2015-01-01

    Potentially economic mineral resources are present in the subsurface in the map area. Exploration drill-hole data indicate that anomalously high concentrations of base-metal sulfides locally occur within the Cambrian Bonneterre Formation. The geologic setting of these anomalous concentrations is similar to that found in the Viburnum Trend, part of the largest lead-mining district in the world. The southernmost part of the Viburnum Trend extends into the northern part of the map area and is exploited by the Sweetwater Mine. Undeveloped and potentially economic occurrences of base metals are known also beneath Blair Creek, a tributary to the Current River in the north-central part of the map area.

  11. Constraints on magma ascent, emplacement, and eruption: geochemical and mineralogical data from drill-core samples at Obsidian dome, Inyo chain, California

    SciTech Connect

    Vogel, T.A.; Younker, L.W.; Schuraytz, B.C.

    1987-05-01

    Systematic chemical and mineralogical variability occurs in samples from drill holes through Obsidian dome, the conduit to the dome, and a nearby associated feeder dike. The drill-hole samples from the margins of the conduit and most of the lower part of the dome are high-Ba, low-silica rhyolites; they contain two populations of phenocrysts and represent commingled magmas, whereas samples from the dike and upper parts of the dome are low-Ba, higher silica rhyolites that do not reflect commingled magmas. Samples from the center of the conduit are low-Ba, higher silica rhyolites that are only slightly mixed. A major part of the variability within the drill-core samples of the dome and conduit reflects the juxtaposition and commingling of two distinct magmas during their passage through the conduit.

  12. Tectonic and karstic effects on the western Taurus region, southwestern Turkey: Relations to the present temperature gradients and total organic carbon content

    SciTech Connect

    Demirel, I.H.; Gunay, Y.

    2000-06-01

    The western Taurus region is one of the promising hydrocarbon provinces and the largest karstic terrain of Turkey. The Mesozoic Beydaglari units deposited in the study area are composed mainly of a carbonate succession which has potential hydrocarbon source rocks of various ages. To confirm the tectonic and karstic influence on the regional temperature gradient and total organic carbon content, subsurface data obtained from four drillholes, and the results of the surface samples and water samples analyses, were used. The low salinity values (less than 2,500 mg/liter) of the formation water, and the measured hole temperatures, indicate the presence of the meteoric water circulation in the geologic section. Since the Late Miocene, intensive tectonic deformations and karstification have provided the development of the aquifer characteristics of the Beydaglari units. Water circulation in the aquifer system has influenced the total organic carbon content and karstic conduits within carbonates.

  13. Anomalous gold, antimony, arsenic, and tungsten in ground water and alluvium around disseminated gold deposits along the Getchell Trend, Humboldt County, Nevada

    USGS Publications Warehouse

    Grimes, D.J.; Ficklin, W.H.; Meier, A.L.; McHugh, J.B.

    1995-01-01

    Ground-water, alluvium, and bedrock samples were collected from drill holes near the Chimney Creek, Preble, Summer Camp, and Rabbit Creek disseminated gold deposits in northern Nevada. Results of chemical analyses of drill-hole water samples show the presence of hydromorphic dispersion anomalies of Au, As, Sb, and W in the local ground-water systems associated with these deposits. In addition, analysis of sequential dissolution and extraction solutions of drill cuttings of alluvium and bedrock indicate geochemical anomalies of gold and ore-related metals in the overburden at depths corresponding to the location of the present-day water table. This relationship suggests that water-rock reactions around these buried deposits are active. -from Authors

  14. Biomechanics of femur fractures secondary to gunshot wounds.

    PubMed

    Smith, H W; Wheatley, K K

    1984-11-01

    Nonlethal gunshot wounds to the femur produce four classical types of fractures. The 'drill-hole,' incomplete, and 'butterfly' fractures have been described in both clinical and experimental settings. The remote spiral fracture, sometimes attributed to the fall on the femur after wounding, is unique to the weight-loaded femur. A mathematical model relying on the beam in bending and the mechanics of a cylindrical shell is offered. An experimental method utilizing an apparatus (the 'osteoclast') designed to apply torsion, bending, or combined forces to cadaveric long bones is discussed. Femur failure proximal or distal to the impact site of a projectile is a function of stress risers operating at relatively great distances. Predictable primary and secondary peak moment locations for fracture are illustrated. PMID:6502770

  15. The influence of geology on blasthole deviation

    SciTech Connect

    Singh, S.P.

    1996-12-31

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

  16. Geophysical investigations of a geothermal anomaly at Wadi Ghadir, eastern Egypt

    NASA Technical Reports Server (NTRS)

    Morgan, P.; Boulos, F. K.; Hennin, S. F.; El-Sherif, A. A.; El-Sayed, A. A.; Basta, N. Z.; Melek, Y. S.

    1984-01-01

    During regional heat flow studies a geothermal anomaly was discovered approximately 2 km from the Red Sea coast at Wadi Ghadir, in the Red Sea Hills of Eastern Egypt. A temperature gradient of 55 C/km was measured in a 150 m drillhole at this location, indicating a heat flow of approximately 175 mw/sqm, approximately four times the regional background heat flow for Egypt. Gravity and magnetic data were collected along Wadi Ghadir, and combined with offshore gravity data, to investigate the source of the thermal anomaly. Magnetic anomalies in the profile do not coincide with the thermal anomaly, but were observed to correlate with outcrops of basic rocks. Other regional heat flow and gravity data indicate that the transition from continental to oceanic type lithosphere occurs close to the Red Sea margin, and that the regional thermal anomaly is possibly related to the formation of the Red Sea.

  17. A note on the frictional strength of laumontite from Cajon Pass, California

    USGS Publications Warehouse

    Morrow, C.A.; Byerlee, J.D.

    1991-01-01

    Laumontite mineralization is pervasive in joints and shear zones encountered in the Cajon Pass drillhole in southern California. In order to determine whether a gouge composed of this hydrated mineral affects shear strength in a manner similar to low-strength, clay-rich fault gouges, frictional sliding experiments were performed under dry, saturated and high pore pressure conditions at effective pressures up to 450 MPa. Coefficients of friction ranged between 0.66 and 0.84, consistent with most crustal rocks and well above the values typical of clay-rich San Andreas fault gouges. Saturation state had no effect on strength or sliding stability. These results suggest that the presence of laumontite in shear zones at Cajon Pass will not affect the shear strength of the rock in a way that can account for the inferred low ambient shear stresses. -Authors

  18. The role of metamorphism of the basaltic basement of sedimentary basins in crustal evolution

    SciTech Connect

    Yakovlev, L.Ye.

    1993-01-01

    A previously unknown but important process-metamorphogenic infiltration of crustal fluids-may take place whenever a thick sedimentary sequence overlies basaltic basement. Alteration of the basalt draws water released during lithification of the sediments, setting up a downward flow of water and its dissolved load. Investigations in the Saatly superdeep drillhole and the surrounding region of the Trans-Caucasus provide evidence for the reality of this process and an indication of its magnitude. Metamorphogenic infiltration of fluids may control redistribution of crustal material through metamorphic differentiation of the basalt complex, accompanied by formation of brines and metallic mineral and petroleum deposits, and development of stress seismic conditions and geothermal anomalies. Further investigation of the new process may show that the downward infiltration can be tapped into and used for disposal of hazardous wastes. 57 refs., 9 figs.

  19. Cerro Prieto geothermal field: exploration during exploitation

    SciTech Connect

    Not Available

    1982-07-01

    Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. The description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field are presented. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development.

  20. Comparison of computer-based and manual coal resource estimation methods for the Cache coal bed, Recluse Geologic Model Area, Wyoming

    USGS Publications Warehouse

    Schneider, Gary B.; Crowley, Sharon S.; Carey, Mary Alice

    1984-01-01

    Coal resources have been estimated, using both manual and computer methods, for the Cache coal bed in the Recluse Geologic Model Area, which covers the White Tail Butte, Pitch Draw, Recluse, and Homestead Draw SW 7?-minute quadrangles in Campbell County, Wyoming. Approximately 300 coal thickness measurements from drill-hole logs are distributed throughout the area The Cache coal bed and associated strata are in the Paleocene Tongue River Member of the Fort Union Formation. The depth to the Cache coal bed ranges from 269 to 1,257 feet. The coal bed is as much as 31 feet thick but is absent in places. Comparisons between hand-drawn and computer-generated isopach maps show minimal differences. Total coal resources estimated by hand show the bed to contain 2,228 million short tons or about 2.6 percent more than the computer-calculated figure of 2,169 million short tons.

  1. CRANBERRY WILDERNESS STUDY AREA, WEST VIRGINIA.

    USGS Publications Warehouse

    Meissner, Charles R., Jr.; Mory, P.C.

    1984-01-01

    The Cranberry Wilderness Study Area, West Virginia contains a large demonstrated resource of bituminous coal of coking quality. Demonstrated coal resources in beds more than 14 in. thick are about 110 million short tons of which 56. 5 million tons are in beds more than 28 in. thick in areas of substantiated coal resource potential. Other mineral resources in the study area include peat, shale and clay suitable for building brick and lightweight aggregate, sandstone suitable for low-quality glass sand, and sandstone suitable for construction material. These commodities are found in abundance in other areas throughout the State. Study of the drill-hole data did not reveal indications of a potential for oil and gas resources in the study area. Evidence of metallic mineral potential was not found during this investigation.

  2. A refined characterization of the alluvial geology of yucca flat and its effect on bulk hydraulic conductivity

    USGS Publications Warehouse

    Phelps, G.A.; Halford, K.J.

    2011-01-01

    In Yucca Flat, on the Nevada National Security Site in southern Nevada, the migration of radionuclides from tests located in the alluvial deposits into the Paleozoic carbonate aquifer involves passage through a thick, heterogeneous section of late Tertiary and Quaternary alluvial sediments. An understanding of the lateral and vertical changes in the material properties of the alluvial sediments will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating groundwater flow in the Yucca Flat area. Previously published geologic models for the alluvial sediments within Yucca Flat are based on extensive examination and categorization of drill-hole data, combined with a simple, data-driven interpolation scheme. The U.S. Geological Survey, in collaboration with Stanford University, is researching improvements to the modeling of the alluvial section, incorporating prior knowledge of geologic structure into the interpolation method and estimating the uncertainty of the modeled hydrogeologic units.

  3. Map showing depth to pre-Cenozoic basement in the Death Valley ground-water model area, Nevada and California

    SciTech Connect

    Blakely, R.J.; Ponce, D.A.

    2002-03-12

    This map shows the depth to pre-Cenozoic basement in the Death Valley ground-water model area. It was prepared utilizing gravity (Ponce and others, 2001), geologic (Jennings and others, 1977; Stewart and Carlson, 1978), and drill-hole information. Geophysical investigations of the Death Valley ground-water model area are part of an interagency effort by the U.S. Geological Survey (USGS) and the U.S. Department of Energy (Interagency Agreement DE-AI08-96NV11967) to help characterize the geology and hydrology of southwestern Nevada and parts of California. The Death Valley ground-water model is located between lat 35 degrees 00' and 38 degrees 15' N., and long 115 degrees and 118 degrees W.

  4. Gravity survey and interpretation of Fort Irwin and vicinity, Mojave Desert, California: Chapter H in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

    USGS Publications Warehouse

    Jachens, Robert C.; Langenheim, V.E.

    2014-01-01

    In support of a hydrogeologic study of the groundwater resources on Fort Irwin, we have combined new gravity data with preexisting measurements to produce an isostatic residual gravity map, which we then separated into two components reflecting (1) the density distribution in the pre-Cenozoic basement complex and (2) the distribution of low-density Cenozoic volcanic and sedimentary deposits that lie on top of the basement complex. The second component was inverted to estimate the three-dimensional distribution of Cenozoic deposits by using constraints from geology, drillholes, and time-domain electromagnetic soundings. In most of the base, the Cenozoic deposits are no more than 300 m thick, except in the basins with more than 500 m of fill beneath Coyote Lake, Red Pass Lake, west of Nelson Lake, west of Superior Lake, Bicycle Lake, and in the vicinity of Nelson Lake.

  5. Permeability of rock samples from Cajon Pass, California

    USGS Publications Warehouse

    Morrow, C.; Byerlee, J.

    1988-01-01

    Room temperature, steady-state flow measurements of permeability were conducted on 15 unfractured core samples collected at depths between 270 and 2100 m in the Cajon Pass drillhole. Confining and pore pressures were set to the lithostat and hydrostat for each depth. The first 500 m encountered in the drill hole is composed of sandstones with typically high permeabilities of around 10-17m2. The crystalline rocks between 500 and 2100 m show a systematic decrease in permeability with depth from 10-19 to less than 10-21m2. These values are particularly low relative to the applied effective stresses of only 10-30 MPa, and may be a result of the extensive crack healing that was observed in most samples. -Authors

  6. National coal resource assessment non-proprietary data: Location, stratigraphy, and coal quality for selected tertiary coal in the Northern Rocky Mountains and Great Plains region

    USGS Publications Warehouse

    Flores, Romeo M.; Ochs, A.M.; Stricker, G.D.; Ellis, M.S.; Roberts, S.B.; Keighin, C.W.; Murphy, E.C.; Cavaroc, V.V., Jr.; Johnson, R.C.; Wilde, E.M.

    1999-01-01

    One of the objectives of the National Coal Resource Assessment in the Northern Rocky Mountains and Great Plains region was to compile stratigraphic and coal quality-trace-element data on selected and potentially minable coal beds and zones of the Fort Union Formation (Paleocene) and equivalent formations. In order to implement this objective, drill-hole information was compiled from hard-copy and digital files of the: (1) U.S. Bureau of Land Management (BLM) offices in Casper, Rawlins, and Rock Springs, Wyoming, and in Billings, Montana, (2) State geological surveys of Montana, North Dakota, and Wyoming, (3) Wyoming Department of Environmental Quality in Cheyenne, (4) U.S. Office of Surface Mining in Denver, Colorado, (5) U.S. Geological Survey, National Coal Resource Data System (NCRDS) in Reston, Virginia, (6) U.S. Geological Survey coal publications, (7) university theses, and (8) mining companies.

  7. Site selection for manned Mars landings: A geological perspective

    NASA Technical Reports Server (NTRS)

    Spudis, Paul D.

    1986-01-01

    Issues relating to the selection of initial landing sites for manned Mars missions are discussed from a geological viewpoint. The two prime objectives for initial manned exploration should be the youngest unambiguous lava flows (to tie down the late end of the cratering history curve for Mars) and old highland crust, which is best sampled and studied through the use of large impact basins as natural, planetary drill-holes. Exploration of these two sites will provide data on Martian chronology, volcanism, impact processes and gross chemical structure that will enable a first-order global synthesis through integration of these results with the global remote-sensing data already in hand from Viking and that to be provided by the Mars Observer Mission.

  8. The mechanisms of overlapping of the Bresse graben by the Jura formations in the Vignoble area (France)

    NASA Astrophysics Data System (ADS)

    Mugnier, Jean Louis; Vialon, Pierre

    1984-06-01

    This paper aims to underline how powerful and important the balanced cross-section constructions are for understanding structural mechanisms, especially when several interpretations are possible. In the Vignoble area, between Lons le Saulnier and Arbois — French foothills of Jura, the frontal overlapping is proved by several drillholes. The classical interpretation is a thrusting through listric reverse faults and continuation of the décollement level underlying the Jura at the cover—basement interface. The balanced cross-section construction demonstrates that this assumption is not valid due to the necessary thinning and stretching of the overlapping formations in this region. This paper proposes a new solution where the overlapping, through listric normal faults, is like a huge gravity landslide, without any relation to the shortening and décollement of the internal Jura. The new interpretation is supported by the very consistent balanced crosssection of the displaced cover and by the extension structures observed in the field.

  9. Subsurface mapping in the Iberian Pyrite Belt using seismic reflection profiling and potential-field data

    NASA Astrophysics Data System (ADS)

    Carvalho, João; Inverno, Carlos; Matos, João Xavier; Rosa, Carlos; Granado, Isabel; Branch, Tim; Represas, Patrícia; Carabaneanu, Livia; Matias, Luís; Sousa, Pedro

    2016-06-01

    The Iberian Pyrite Belt (IPB) hosts world-class massive sulphide deposits, such as Neves-Corvo in Portugal and Rio Tinto in Spain. In Portugal, the Palaeozoic Volcanic-Sedimentary Complex (VSC) hosts these ore deposits, extending from the Grândola-Alcácer region to the Spanish border with a NW-SE to WNW-ESE trend. In the study area, between the Neves-Corvo mine region and Alcoutim (close to the Spanish border), the VSC outcrops only in a small horst near Alcoutim. Sparse exploration drill-hole data indicate that the depth to the top of the VSC varies from several 100 m to about 1 km beneath the Mértola Formation Flysch cover. Mapping of the VSC to the SE of Neves-Corvo mine is an important exploration goal and motivated the acquisition of six 2D seismic reflection profiles with a total length of approximately 82 km in order to map the hidden extension of the VSC. The data, providing information deeper than 10 km at some locations, were integrated in a 3D software environment along with potential-field, geological and drill-hole data to form a 3D structural framework model. Seismic data show strong reflections that represent several long Variscan thrust planes that smoothly dip to the NNE. Outcropping and previously unknown Late Variscan near-vertical faults were also mapped. Our data strongly suggest that the structural framework of Neves-Corvo extends south-eastwards to Alcoutim. Furthermore, the VSC top is located at depths that show the existence within the IPB of new areas with good potential to develop exploration projects envisaging the discovery of massive sulphide deposits of the Neves-Corvo type.

  10. Evaluation of hydrocarbon potential, Task 8

    SciTech Connect

    Cashman, P.H.; Trexler, J.H. Jr.

    1993-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vicinity. Our main focus is source rock stratigraphy in the Nevada Test Site (NTS) area in southern Nevada. In order to reconstruct the Paleozoic stratigraphy, we are also studying the geometry and kinematics of deformation at NTS. A thorough understanding of the structure will also be essential to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We are now provisionally limiting the name {open_quotes}Eleana Formation{close_quotes} to the rocks that make up the Eleana Range - i.e., the rocks that we have been calling {open_quotes}western Eleana{close_quotes}. The mudstone section (which we have until now called {open_quotes}eastern Eleana{close_quotes}) we are provisionally calling the {open_quotes}Chainman Shale{close_quotes}, in keeping with regional lithostratigraphic nomenclature. We continue to work out the internal stratigraphies and basin histories of both units; XRD (r-ray diffraction) determinations of clay mineralogy are an addition to our understanding of the Chainman. The basin histories place important constraints on regional paleogeographic and tectonic reconstructions. This year we have hired a consulting petroleum geologist for two jobs: (1) to review drillhole data from southern Nevada on file at NBMG and make recommendations about more detailed study of any interesting drillholes; and (2) to log the UE17e core (in the Chainman) and evaluate source rock potential. The results of these studies have been incorporated into this report, and the consultant`s reports.

  11. ER-12-1 completion report

    SciTech Connect

    Russell, C.E.; Gillespie, D.; Cole, J.C.; Drellack, S.L.

    1996-12-01

    The objective of drillhole ER-12-1 was to determine the hydrogeology of paleozoic carbonate rocks and of the Eleana Formation, a regional aquitard, in an area potentially downgradient from underground nuclear testing conducted in nearby Rainier Mesa. This objective was addressed through the drilling of well ER-12-1 at N886,640.26 E640,538.85 Nevada Central Coordinates. Drilling of the 1094 m (3588 ft) well began on July 19, 1991 and was completed on October 17, 1991. Drilling problems included hole deviation and hole instability that prevented the timely completion of this borehole. Drilling methods used include rotary tri-cone and rotary hammer drilling with conventional and reverse circulation using air/water, air/foam (Davis mix), and bentonite mud. Geologic cuttings and geophysical logs were obtained from the well. The rocks penetrated by the ER-12-1 drillhole are a complex assemblage of Silurian, Devonian, and Mississippian sedimentary rocks that are bounded by numerous faults that show substantial stratigraphic offset. The final 7.3 m (24 ft) of this hole penetrated an unusual intrusive rock of Cretaceous age. The geology of this borehole was substantially different from that expected, with the Tongue Wash Fault encountered at a much shallower depth, paleozoic rocks shuffled out of stratigraphic sequence, and the presence of an altered biotite-rich microporphyritic igneous rock at the bottom of the borehole. Conodont CAI analyses and rock pyrolysis analyses indicate that the carbonate rocks in ER-12-1, as well as the intervening sheets of Eleana siltstone, have been thermally overprinted following movement on the faults that separate them. The probable source of heat for this thermal disturbance is the microporphyritic intrusion encountered at the bottom of the hole, and its age establishes that the major fault activity must have occurred prior to 102.3+0.5 Ma (middle Cretaceous).

  12. Hydrogeologic role of geologic structures. Part 2: analytical models

    NASA Astrophysics Data System (ADS)

    Levens, Russell L.; Williams, Roy E.; Ralston, Dale R.

    1994-04-01

    This paper is the second of two papers that address the influence of geologic structures on ground water flow at various scales in fractured rocks. The ultimate purpose of this research is to investigate the feasibility of grouting preferentially permeable zones as a strategy to minimize the production of acid mine drainage in underground hard rock mines in which the major permeability is structure and fracture controlled. The aim of grouting is to reduce permeability around mined-out openings, to minimize the rate of inflow of ground water into such openings via the structurally controlled preferentially permeable pathways. A series of hydraulic stress tests were conducted to help characterize the role of geologic structures in controlling the ground water flow system in the vicinity of the Bunker Hill Mine in north Idaho. The results of these tests indicate that most of the ground water that flows from the underground drillholes used for hydraulic stress testing is derived from a few discrete, structurally produced fracture zones that are more or less connected through smaller-scale fractures. Four types of analytical models are considered as a means of analyzing the results of multiple drillhole hydraulic stress tests, as follows: cross-hole equivalent porous media; double-porosity equivalent porous media; a solution to flow in and around a single vertical fracture; leaky equivalent porous media, partial penetration. The estimation of hydraulic coefficients in complex fractured rock environments involves the combined application of a number of deterministic analytical models. The models to be used are selected dependent on the location of the drawdown observations relative to the water-producing zone and the length of the test. The result of the tests can be related to the permeability hierarchy discussed in our first paper.

  13. “Imaging” the cross section of oceanic lithosphere: The development and future of electrical microresistivity logging through scientific ocean drilling

    NASA Astrophysics Data System (ADS)

    Tominaga, Masako

    2013-11-01

    A detailed understanding of the architecture of volcanic and magmatic lithologies present within the oceanic lithosphere is essential to advance our knowledge of the geodynamics of spreading ridges and subduction zones. Undertaking sub-meter scale observations of oceanic lithosphere is challenging, primarily because of the difficulty in direct continuous sampling (e.g., by scientific ocean drilling) and the limited resolution of the majority of geophysical remote sensing methods. Downhole logging data from drillholes through basement formations, when integrated with recovered core and geophysical remote sensing data, can provide new insights into crustal accretion processes, lithosphere hydrogeology and associated alteration processes, and variations in the physical properties of the oceanic lithosphere over time. Here, we introduce an alternative approach to determine the formation architecture and lithofacies of the oceanic sub-basement by using logging data, particularly utilizing downhole microresistivity imagery (e.g. Formation MicroScanner (FMS) imagery), which has the potential to become a key tool in deciphering the high-resolution internal architecture of the intact upper ocean crust. A novel ocean crust lithostratigraphy model based on meticulously deciphered lava morphology determined by in situ FMS electrofacies analysis of holes drilled during Ocean Drilling Program legs (1) advances our understanding of ocean crust formation and accretionary processes over both time and space; and (2) allows the linking of local igneous histories deciphered from the drillholes to the regional magmatic and tectonic histories. Furthermore, microresistivity imagery can potentially allow the investigation of (i) magmatic lithology and architecture in the lower ocean crust and upper mantle; and, (ii) void space abundances in crustal material and the determination of complex lithology-dependent void geometries.

  14. Contact metamorphism, partial melting and fluid flow in the granitic footwall of the South Kawishiwi Intrusion, Duluth Complex, USA

    NASA Astrophysics Data System (ADS)

    Benko, Z.; Mogessie, A.; Molnar, F.; Severson, M.; Hauck, S.; Lechler, P.; Arehart, G.

    2012-04-01

    The footwall of the South Kawishiwi Intrusion (SKI) a part of the Mesoproterozoic (1.1 Ga) Duluth Complex consists of Archean granite-gneiss, diorite, granodiorite (Giant Range Batholith), thin condensed sequences of Paleoproterozoic shale (Virginia Fm.), as well as banded iron formation (Biwabik Iron Fm). Detailed (re)logging and petrographic analysis of granitic footwall rocks in the NM-57 drillhole from the Dunka Pit area has been performed to understand metamorphic processes, partial melting, deformation and geochemical characteristics of de-volatilization or influx of fluids. In the studied drillhole the footwall consists of foliated metagranite that is intersected by mafic (dioritic) dykes of older age than the SKI. In the proximal contact zones, in the mafic dykes, the orthopyroxene+clinopyroxene+plagioclase+quartz+Fe-Ti-oxide+hornblende±biotite porphyroblasts embedded in a plagioclase+K-feldspar+orthopyroxene+apatite matrix indicate pyroxene-hornfels facies conditions. Migmatitization is revealed by the euhedral crystal faces of plagioclase and pyroxene against anhedral quartz crystals in the in-situ leucosome and by the presence of abundant in-source plagioclase±biotite leucosome veinlets. Amphibole in the melanosome of mafic dykes was formed with breakdown of biotite and implies addition of H2O to the system during partial melting. Towards the deeper zones, the partially melted metatexite-granite can be characterized by K-feldspar+plagioclase+quartz+ortho/clinopyroxene+biotite+Fe-Ti-oxide+apatite mineral assemblage. The felsic veins with either pegmatitic or aplititic textures display sharp contact both to the granite and the mafic veins. They are characterized by K-feldspar+quartz±plagioclase±muscovite mineral assemblage. Sporadic occurrence of muscovite suggest local fluid saturated conditions. Emplacement of gabbroic rocks of the SKI generated intense shear in some zones of the granitic footwall resulting in formation of biotite-rich mylonites with

  15. The deep structure of the Western Pyrenees: constraints from tomographic imaging, field and marine geological observations

    NASA Astrophysics Data System (ADS)

    Tugend, Julie; Manatschal, Gianreto; Chevrot, Sébastien; Mohn, Geoffroy

    2015-04-01

    Knowledge of magma-poor rifted margin architecture has significantly evolved over the past decades. Refraction seismic data combined with drill-hole observations unravelled the velocity structure and lithological assemblages of the most distal part of continental rifted margins. Present-day models of continental rifted margins include the occurrence of hyperextended domains consisting in extremely thinned continental crust and/or exhumed subcontinental mantle as described at many rifted margins. Studies in mountain belts revealed that remnants of hyperextended domains could also be identified in internal parts of collisional orogens. Integrating recent developments in the understanding of rifted margins in the study of mountain building processes, in particular the importance of the reactivation of inherited rift structures is therefore essential and may result in alternative interpretations of the lithospheric scale structure of collisional orogens. In this contribution, we focus on the western part of the Pyrenean orogen that resulted from the inversion of a complex Late Jurassic to Mid Cretaceous rift system. The transition from preserved oceanic and rift domains to the west (in the offshore Bay of Biscay) to their complete inversion in the east provides simultaneous access to seismically imaged and exposed parts of a hyperextended rift system. Based on a multi-scale dataset that combines sub-surface data (field and drill-hole observations) with tomographic imaging (PYROPE experiment) and integrating new concepts derived from the study of present-day rifted margins, we investigate the lithospheric-scale architecture of the Western Pyrenees. Our results suggest that the imaged north-dipping crustal root may correspond to the former exhumed mantle and hyperthinned domains that have been subducted/underthrust at the onset of convergence. This interpretation contrasts with the classical assumption that the crustal root is made of lower crustal rocks. This

  16. Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - I. A simple damage structure inferred from borehole core permeability

    USGS Publications Warehouse

    Lockner, D.A.; Tanaka, H.; Ito, H.; Ikeda, R.; Omura, K.; Naka, H.

    2009-01-01

    The 1995 Kobe (Hyogo-ken Nanbu) earthquake, M = 7.2, ruptured the Nojima fault in southwest Japan. We have studied core samples taken from two scientific drillholes that crossed the fault zone SW of the epicentral region on Awaji Island. The shallower hole, drilled by the Geological Survey of Japan (GSJ), was started 75 m to the SE of the surface trace of the Nojima fault and crossed the fault at a depth of 624 m. A deeper hole, drilled by the National Research Institute for Earth Science and Disaster Prevention (NIED) was started 302 m to the SE of the fault and crossed fault strands below a depth of 1140 m. We have measured strength and matrix permeability of core samples taken from these two drillholes. We find a strong correlation between permeability and proximity to the fault zone shear axes. The half-width of the high permeability zone (approximately 15 to 25 m) is in good agreement with the fault zone width inferred from trapped seismic wave analysis and other evidence. The fault zone core or shear axis contains clays with permeabilities of approximately 0.1 to 1 microdarcy at 50 MPa effective confining pressure (10 to 30 microdarcy at in situ pressures). Within a few meters of the fault zone core, the rock is highly fractured but has sustained little net shear. Matrix permeability of this zone is approximately 30 to 60 microdarcy at 50 MPa effective confining pressure (300 to 1000 microdarcy at in situ pressures). Outside this damage zone, matrix permeability drops below 0.01 microdarcy. The clay-rich core material has the lowest strength with a coefficient of friction of approximately 0.55. Shear strength increases with distance from the shear axis. These permeability and strength observations reveal a simple fault zone structure with a relatively weak fine-grained core surrounded by a damage zone of fractured rock. In this case, the damage zone will act as a high-permeability conduit for vertical and horizontal flow in the plane of the fault. The fine

  17. Structural evolution of the Currawong Pb-Zn-Cu deposit (Victoria, Australia) - new insights from 3D implicit modelling linked to structural observations

    NASA Astrophysics Data System (ADS)

    Vollgger, Stefan; Cruden, Alexander

    2015-04-01

    Structurally controlled mineralisation commonly shows distinctive geometries, orientations and spatial distributions that derive from associated structures. These structures have the ability to effectively transport, trap and focus fluids. Moreover, structures such as faults and shear zones can offset, truncate and spatially redistribute earlier mineralisation. We present a workflow that combines structural fieldwork with state-of-the-art 3D modelling to assess the structural framework of an ore deposit. Traditional 3D models of ore deposits rely on manual digitisation of cross sections and their subsequent linkage to form 3D objects. Consequently, the geological interpretation associated with each section will be reflected in the resulting 3D models. Such models are therefore biased and should be viewed and interpreted with caution. Conversely, 3D implicit modelling minimises the modelling bias by using an implicit function that is fitted to spatial data such as drillhole data. This function defines a scalar field, from which 3D isosurfaces can be extracted. Assay data can be visualised as 3D grade shells at various threshold grade values and used to analyse and measure the shape, distribution and orientation of mineralisation. Additionally, lithology codes from drillholes can be used to extract lithological boundaries in 3D without the need for manual digitisation. In our case study at the Palaeozoic Currawong Pb-Zn-Cu deposit (Victoria, Australia), orientations extracted from ore bodies within a 3D implicit model have been compared to structural field data collected around the deposit. The data and model suggest that Currawong's massive sulfide lenses have been structurally modified. Mineralisation trends are parallel to a dominant NW dipping foliation mapped in the field. This foliation overprints earlier bedding in the host metasediments that has been deformed into upright folds. Several sets of steep faults further increase the structural complexity of the

  18. Using mineralogical and geochemical data as a tool for determining potential environmental changes

    NASA Astrophysics Data System (ADS)

    Perunović, Tamara; Jovančićević, Branimir; Brčeski, Ilija; Šajnović, Aleksandra; Stojanović, Ksenija; Simić, Vlada; Kašanin-Grubin, Milica

    2014-05-01

    Neogene lacustrine basins are often bearing coal, oil-shale and non-metallic minerals such as magnesite, borates and marls. Exploration of these deposits could put a lot of pressure on the landscape. Aim of this research is to show that geochemical and mineralogical data could be used as a tool in determining landscape sensitivity to an imposed change. To test this hypothesis Lower Miocen lacustrine Kremna basin, Serbia, was investigated. Kremna basin covers an area of approximately 15 km2 and is located in SW Serbia. For the purpose of this study, geomorphologic and microclimatic characteristics of the area were assessed and geochemical and mineralogical composition of 43 sediment samples from one borehole was determined. The purpose of the drilling was to determine the possible evaporite deposit and boron occurrence. The borehole was 343 m deep and ended in weathered serpentinite. Landscape of Kremna basin is hilly-mountainous with pastures, meadows and agriculture as dominant vegetation type. The area is sparsely populated with mountain villages dispersed and mostly isolated. Main water supplies for villages are springs. Climate data (1961-2012) indicate that the average precipitation is 988 mm, and temperature 7,5oC. However, variations in climatic conditions are evident since 1990 showing more profound change between colder and wetter, and warmer and drier years alternating every two to three years. The base and the edge of the Kremna basin consist predominantly of ultrabasic rocks, serpentinite and ophiolitic mélange, which are all prone to weathering. Drill-hole date showed that uppermost clay and Mg rich sediments were overlain by a thin soil layer (~ 15cm). Leaching tests performed on these uppermost sediments indicated that they are dispersive and prone to erosion. Higher average concentration of boron and certain heavy metals, as well as presents of Cr, Hg, As, Pb, Ni, Th, U was determined. Effect of these elements on the environment can be highly

  19. A multiple-point geostatistical approach to quantifying uncertainty for flow and transport simulation in geologically complex environments

    NASA Astrophysics Data System (ADS)

    Cronkite-Ratcliff, C.; Phelps, G. A.; Boucher, A.

    2011-12-01

    In many geologic settings, the pathways of groundwater flow are controlled by geologic heterogeneities which have complex geometries. Models of these geologic heterogeneities, and consequently, their effects on the simulated pathways of groundwater flow, are characterized by uncertainty. Multiple-point geostatistics, which uses a training image to represent complex geometric descriptions of geologic heterogeneity, provides a stochastic approach to the analysis of geologic uncertainty. Incorporating multiple-point geostatistics into numerical models provides a way to extend this analysis to the effects of geologic uncertainty on the results of flow simulations. We present two case studies to demonstrate the application of multiple-point geostatistics to numerical flow simulation in complex geologic settings with both static and dynamic conditioning data. Both cases involve the development of a training image from a complex geometric description of the geologic environment. Geologic heterogeneity is modeled stochastically by generating multiple equally-probable realizations, all consistent with the training image. Numerical flow simulation for each stochastic realization provides the basis for analyzing the effects of geologic uncertainty on simulated hydraulic response. The first case study is a hypothetical geologic scenario developed using data from the alluvial deposits in Yucca Flat, Nevada. The SNESIM algorithm is used to stochastically model geologic heterogeneity conditioned to the mapped surface geology as well as vertical drill-hole data. Numerical simulation of groundwater flow and contaminant transport through geologic models produces a distribution of hydraulic responses and contaminant concentration results. From this distribution of results, the probability of exceeding a given contaminant concentration threshold can be used as an indicator of uncertainty about the location of the contaminant plume boundary. The second case study considers a

  20. Orbitally-paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene Climatic Optimum

    NASA Astrophysics Data System (ADS)

    Passchier, S.; Falk, C. J.; Florindo, F.; Sangiorgi, F.

    2012-12-01

    The AND-2A drillhole at ca. 10 km from the east Antarctic coastline records nearly 6 million years of sedimentation across the Miocene Climatic Optimum at a high-latitude site. We collected and interpreted a laser particle size record on 300 samples in the upper 855 m of the drillhole. Within the expanded early to mid-Miocene section (~17.6 to 15.7 Ma), in an interval characterized by hemipelagic deposition and deposition from floating ice, we document changes in mud percent within glacial-interglacial cycles, which we attribute to the hydrodynamic effects of wave stirring tied to episodes of ice growth and decay. Bedforms logged from the cut face of the core confirm that the sedimentation was strongly affected by changes in the strength of shelf currents (waves). Spectral analysis demonstrates that the mud percent displays cyclicity within the short-eccentricity band (99 kyr), suggestive of low-latitude climate forcing. Both wave climate and paleobathymetry affect wave stirring, and we argue that through these variables its intensity and impact on the particle size record is ultimately forced by the size of the ice sheet. Ice sheet and climate modeling studies indicate that ice retreat likely negatively impacts the wave-dampening effect of floating ice, and increases atmospheric pressure gradients and wind speed. Further, geodynamic modeling studies of glacio-isostatic and self-gravitation effects of the collapse of marine sectors of the Antarctic ice sheet have shown a decrease in paleobathymetry at the high-latitude AND-2A site, which would enhance wave stirring. The exact contributions of wave climate and paleobathymetric changes cannot be quantified without further regional modeling. However, despite uncertainties in the relative importance of these contributing forcings, wave stirring intensity and ice volume are anticorrelated for the AND-2A site and the particle size record can be viewed as a near-field ice volume proxy. Under the Miocene polythermal

  1. Using airborne magnetic data to map folding and faulting in sedimentary layers: implications for seismic hazard (Invited)

    NASA Astrophysics Data System (ADS)

    Langenheim, V. E.; Jachens, R. C.; Phelps, G. A.; Simpson, R. W.

    2010-12-01

    Aeromagnetic surveys are increasingly used to map structure within sedimentary rocks important for seismic assessment as better magnetometers, positioning, and techniques are developed. We present three examples in which aeromagnetic data are used to map folding and faulting within Cenozoic sedimentary rocks and deposits. In the Salton Trough, detailed aeromagnetic data collected in 1990 suffered from leveling problems that obscured low-amplitude (less than 2-3 nT) magnetic anomalies arising from Tertiary sedimentary rocks. Decorrugation and subtraction of a regional field (upward continuation of 100 m) isolated and enhanced these low-amplitude anomalies, some of which extend the length of the Clark fault, a major strand of the San Jacinto fault zone in southern California, another 20-25 km southwest of its termination point. Other anomalies point to distributed deformation confirmed by detailed surficial mapping by geologists. Detailed aeromagnetic data in the San Ramon Valley, California area show curvilinear anomalies that arise from folding and faulting of the Neroly sandstone, a Miocene unit whose magnetization is due to andesitic detritus. Detailed geologic maps and drillholes locally constrain the geometry of the Neroly Formation at the surface and subsurface, but constrained inversion of aeromagnetic data identified folds not earlier seen. In northern California (e.g. Ukiah), similar long (up to 50 km), curvilinear magnetic anomalies also occur, but in an area where drillholes are absent and geologic mapping is limited by dense vegetation, steep slopes, abundant landsliding, and thick soils. Magnetic susceptibility measurements from sparse outcrops show that the anomalies arise from lithic, volcanic-rich graywacke and metabasalt within the Franciscan Complex. The similarity in anomaly characteristics between the San Ramon and Ukiah areas suggests that the graywackes are folded, coherent bodies within an assemblage that at the surface is termed

  2. Regional liquefaction hazard evaluation following the 2010-2011 Christchurch (New Zealand) earthquake sequence

    NASA Astrophysics Data System (ADS)

    Begg, John; Brackley, Hannah; Irwin, Marion; Grant, Helen; Berryman, Kelvin; Dellow, Grant; Scott, David; Jones, Katie; Barrell, David; Lee, Julie; Townsend, Dougal; Jacka, Mike; Harwood, Nick; McCahon, Ian; Christensen, Steve

    2013-04-01

    Following the damaging 4 Sept 2010 Mw7.1 Darfield Earthquake, the 22 Feb 2011 Christchurch Earthquake and subsequent damaging aftershocks, we completed a liquefaction hazard evaluation for c. 2700 km2 of the coastal Canterbury region. Its purpose was to distinguish at a regional scale areas of land that, in the event of strong ground shaking, may be susceptible to damaging liquefaction from areas where damaging liquefaction is unlikely. This information will be used by local government for defining liquefaction-related geotechnical investigation requirements for consent applications. Following a review of historic records of liquefaction and existing liquefaction assessment maps, we undertook comprehensive new work that included: a geologic context from existing geologic maps; geomorphic mapping using LiDAR and integrating existing soil map data; compilation of lithological data for the surficial 10 m from an extensive drillhole database; modelling of depth to unconfined groundwater from existing subsurface and surface water data. Integrating and honouring all these sources of information, we mapped areas underlain by materials susceptible to liquefaction (liquefaction-prone lithologies present, or likely, in the near-surface, with shallow unconfined groundwater) from areas unlikely to suffer widespread liquefaction damage. Comparison of this work with more detailed liquefaction susceptibility assessment based on closely spaced geotechnical probes in Christchurch City provides a level of confidence in these results. We tested our susceptibility map by assigning a matrix of liquefaction susceptibility rankings to lithologies recorded in drillhole logs and local groundwater depths, then applying peak ground accelerations for four earthquake scenarios from the regional probabilistic seismic hazard model (25 year return = 0.13g; 100 year return = 0.22g; 500 year return = 0.38g and 2500 year return = 0.6g). Our mapped boundary between liquefaction-prone areas and areas

  3. Economics of Developing Hot Stratigraphic Reservoirs

    SciTech Connect

    Greg Mines; Hillary Hanson; Rick Allis; Joseph Moore

    2014-09-01

    Stratigraphic geothermal reservoirs at 3 – 4 km depth in high heat-flow basins are capable of sustaining 100 MW-scale power plants at about 10 c/kWh. This paper examines the impacts on the levelized cost of electricity (LCOE) of reservoir depth and temperature, reservoir productivity, and drillhole/casing options. For a reservoir at 3 km depth with a moderate productivity index by hydrothermal reservoir standards (about 50 L/s/MPa, 5.6 gpm/psi), an LCOE of 10c/kWh requires the reservoir to be at about 200°C. This is the upper temperature limit for pumps. The calculations assume standard hydrothermal drilling costs, with the production interval completed with a 7 inch liner in an 8.5 inch hole. If a reservoir at 4 km depth has excellent permeability characteristics with a productivity index of 100 L/s/MPa (11.3 gpm/psi), then the LCOE is about 11 c/kWh assuming the temperature decline rate with development is not excessive (< 1%/y, with first thermal breakthrough delayed by about 10 years). Completing wells with modest horizontal legs (e.g. several hundred meters) may be important for improving well productivity because of the naturally high, sub-horizontal permeability in this type of reservoir. Reducing the injector/producer well ratio may also be cost-effective if the injectors are drilled as larger holes.

  4. Tensor controlled-source audiomagnetotelluric survey over the Sulphur Springs thermal area, Valles Caldera

    SciTech Connect

    Wannamaker, P.E.

    1991-10-01

    The extensive tensor CSAMT survey of the Sulphur Springs geothermal area, Valles Caldera, New Mexico, consists of 45 high-quality soundings acquired in continuous-profiling mode and has been funded in support of CSDP drillholes VC-2A and VC-2B. Two independent transmitter bipoles were energized for tensor measurements using a 30 KW generator placed approximately 13 km south of the VC-2B wellhead. These current bipoles gave source fields over the receiver sites which were substantially independent in polarization and provided well-resolved tensor elements. The surroundings in the Sulphur Springs area were arranged in four profiles to cross major structural features. At each receiver, two orthogonal electric and three orthogonal magnetic field components were acquired in accordance with tensor principles. Derivation of model resistivity cross sections from our data and their correlation with structure and geochemistry are principal components of the OBES award. However, Sulphur Springs also can serve as a natural testbed of traditional assumptions and methods of CSAMT with quantification through rigorous model analysis. Issues here include stability and accuracy of scalar versus tensor estimates, theoretical versus observed field patterns over the survey area, and controls on near-field effects using CSAMT and natural field data both inside and outside the caldera.

  5. Introduction to the hydrogeochemical investigations within the International Stripa Project

    USGS Publications Warehouse

    Nordstrom, D.K.; Olsson, T.; Carlsson, L.; Fritz, P.

    1989-01-01

    The International Stripa Project (1980-1990) has sponsored hydrogeochemical investigations at several subsurface drillholes in the granitic portion of an abandoned iron ore mine, central Sweden. The purpose has been to advance our understanding of geochemical processes in crystalline bedrock that may affect the safety assessment of high-level radioactive waste repositories. More than a dozen investigators have collected close to a thousand water and gas samples for chemical and isotopic analyses to develop concepts for the behavior of solutes in a granitic repository environment. The Stripa granite is highly radioactive and has provided an exceptional opportunity to study the behavior of natural radionuclides, especially subsurface production. Extensive microfracturing, low permeability with isolated fracture zones of high permeability, unusual water chemistry, and a typical granitic mineral assemblage with thin veins and fracture coatings of calcite, chlorite, seriate, epidote and quartz characterize the site. Preliminary groundwater flow modeling indicates that the mine has perturbed the flow environment to a depth of about 3 km and may have induced deep groundwaters to flow into the mine. ?? 1989.

  6. Monitoring roof beam lateral displacement at the waste isolation pilot plant

    SciTech Connect

    Terrill, L.J.; Lewis, R.E.

    1996-08-01

    Lateral displacement in the immediate roof beam at the Waste Isolation Pilot Plant (WIPP) is a significant factor in assessment of excavation performance for the design of ground control systems. Information on roof beam lateral displacement, expansion, fracture formation, as well as excavation convergence, is gathered using a variety of manually and remotely read instruments. Visual observations are also used when possible. This paper describes the methods used to measure lateral displacement, or offset, at the WIPP. Offset magnitudes are determined by the degree of occlusion in drillholes that intersect the offset plane. The Borehole Lateral Displacement Sensor (BLDS) was developed for installation at WIPP to monitor offset at a high degree of accuracy at a short reading frequency. Offset measurements have historically been obtained by visual estimation of borehole occlusion. Use of the BLDS will enable relationships between time dependent roof beam lateral displacement and expansion to be established in much shorter periods than is possible using visual observations. The instrument will also allow remote monitoring of roof beam displacement in areas where visual estimations are not possible. Continued monitoring of roof beam displacement, convergence, and expansion, is integral to timely and pertinent assessments of WIPP excavation performance.

  7. The national coal-resources data system of the U.S. geological survey

    USGS Publications Warehouse

    Carter, M.D.

    1976-01-01

    The National Coal Resources Data System (NCRDS) was designed by the U.S. Geological Survey (USGS) to meet the increasing demands for rapid retrieval of information on coal location, quantity, quality, and accessibility. An interactive conversational query system devised by the USGS retrieves information from the data bank through a standard computer terminal. The system is being developed in two phases. Phase I, which currently is available on a limited basis, contains published areal resource and chemical data. The primary objective of this phase is to retrieve, calculate, and tabulate coal-resource data by area on a local, regional, or national scale. Factors available for retrieval include: state, county, quadrangle, township, coal field, coal bed, formation, geologic age, source and reliability of data, and coal-bed rank, thickness, overburden, and tonnage, or any combinations of variables. In addition, the chemical data items include individual values for proximate and ultimate analyses, BTU value, and several other physical and chemical tests. Information will be validated and deleted or updated as needed. Phase II is being developed to store, retrieve, and manipulate basic point source coal data (e.g., field observations, drill-hole logs), including geodetic location; bed thickness; depth of burial; moisture; ash; sulfur; major-, minor-, and trace-element content; heat value; and characteristics of overburden, roof rocks, and floor rocks. The computer system may be used to generate interactively structure-contour or isoline maps of the physical and chemical characteristics of a coal bed or to calculate coal resources. ?? 1976.

  8. LavaNet—Neural network development environment in a general mine planning package

    NASA Astrophysics Data System (ADS)

    Kapageridis, Ioannis Konstantinou; Triantafyllou, A. G.

    2011-04-01

    LavaNet is a series of scripts written in Perl that gives access to a neural network simulation environment inside a general mine planning package. A well known and a very popular neural network development environment, the Stuttgart Neural Network Simulator, is used as the base for the development of neural networks. LavaNet runs inside VULCAN™—a complete mine planning package with advanced database, modelling and visualisation capabilities. LavaNet is taking advantage of VULCAN's Perl based scripting environment, Lava, to bring all the benefits of neural network development and application to geologists, mining engineers and other users of the specific mine planning package. LavaNet enables easy development of neural network training data sets using information from any of the data and model structures available, such as block models and drillhole databases. Neural networks can be trained inside VULCAN™ and the results be used to generate new models that can be visualised in 3D. Direct comparison of developed neural network models with conventional and geostatistical techniques is now possible within the same mine planning software package. LavaNet supports Radial Basis Function networks, Multi-Layer Perceptrons and Self-Organised Maps.

  9. Fault geometry and cumulative offsets in the central Coast Ranges, California: Evidence for northward increasing slip along the San Gregorio-San Simeon-Hosgri fault

    USGS Publications Warehouse

    Langenheim, V.E.; Jachens, R.C.; Graymer, R.W.; Colgan, J.P.; Wentworth, C.M.; Stanley, R.G.

    2012-01-01

    Estimates of the dip, depth extent, and amount of cumulative displacement along the major faults in the central California Coast Ranges are controversial. We use detailed aeromagnetic data to estimate these parameters for the San Gregorio–San Simeon–Hosgri and other faults. The recently acquired aeromagnetic data provide an areally consistent data set that crosses the onshore-offshore transition without disruption, which is particularly important for the mostly offshore San Gregorio–San Simeon–Hosgri fault. Our modeling, constrained by exposed geology and in some cases, drill-hole and seismic-reflection data, indicates that the San Gregorio–San Simeon–Hosgri and Reliz-Rinconada faults dip steeply throughout the seismogenic crust. Deviations from steep dips may result from local fault interactions, transfer of slip between faults, or overprinting by transpression since the late Miocene. Given that such faults are consistent with predominantly strike-slip displacement, we correlate geophysical anomalies offset by these faults to estimate cumulative displacements. We find a northward increase in right-lateral displacement along the San Gregorio–San Simeon–Hosgri fault that is mimicked by Quaternary slip rates. Although overall slip rates have decreased over the lifetime of the fault, the pattern of slip has not changed. Northward increase in right-lateral displacement is balanced in part by slip added by faults, such as the Reliz-Rinconada, Oceanic–West Huasna, and (speculatively) Santa Ynez River faults to the east.

  10. Erschließung eines Marmorkarstvorkommens als mitteltiefer Erdwärmesondenspeicher im Tuxertal, Tirol

    NASA Astrophysics Data System (ADS)

    Sass, Ingo; Heldmann, Claus-Dieter; Lehr, Clemens

    2016-06-01

    Borehole heat exchangers can be economically beneficial for meeting heating and cooling demands of houses or buildings. In karst aquifers development of thermal storage and exchange systems may be problematic in terms of groundwater protection and storage design, due to possibly high groundwater velocities. The new development of the Hochstegen marble unit in the Tux Valley (Zillertal, Austria) was designed in two stages for the requested cooling and heating demands. An enhanced geothermal response test was completed using optical frequency domain reflectometry in an exploration drillhole. Additional studies focussing on local geology and hydrology were also conducted. Geothermal parameters obtained at precise depths allowed differentiating between conductive and convective heat flow and were correlated with the lithostratigraphically-conditioned karst characteristics. The borehole heat exchanger field was developed with nine 400 m deep dual U-shaped tube probes in 2013 for 1 GWh/a extraction and 400 MWh/a induction. Along with borehole geophysics and geothermal response tests, the study has provided relevant geothermal data for improving storage design and exploration.

  11. Cretaceous - Tertiary Hoploparia species: Occurrence, paleobiogeography and predation context

    NASA Astrophysics Data System (ADS)

    El-Shazly, Soheir

    2015-12-01

    The study of Hoploparia species in 25 localities in Northern and Southern Hemispheres from Early Cretaceous to Early Miocene reveals the appearance of 51 species in Early Cretaceous, mostly in Northern Hemisphere, 46 species from Late Cretaceous (42 and 4 carryover from the Early Cretaceous), 7 species from Danian (4 plus 3 carryover from the Late Cretaceous), 7 species from Eocene (6 plus one from the Early Cretaceous), 2 species from Lower Oligocene and the last recorded species Hoploparia persisted in the Early Miocene of Antarctica. The oldest Hoploparia was recorded from Europe and distributed through the Northern and Southern Hemispheres with the facilitation of the Indo-Madagascar sea-way and Hispanic corridor. The tolerance for temperature and water depth as well as the morphological changes in genus Hoploparia in the Late Cretaceous and Tertiary periods, helped some species to survive the K/T event. Drill-hole predation in Hoploparia longimana (Sowerby, 1826) was recorded for the first time from the Lower Cretaceous (Albian) of Egypt.

  12. Early and Middle Miocene Antarctic Climate and Ice Sheet variability: ANDRILL SMS Project results

    NASA Astrophysics Data System (ADS)

    Harwood, David; Florindo, Fabio; Levy, Richard; Talarico, Franco; Sms Project Science Team Members

    2010-05-01

    The sedimentary archive recovered during the ANDRILL Southern McMurdo Sound Project (SMS) comprises an expanded early and middle Miocene section deposited in a high-accommodation continental margin location, proximal to glacial ice influence from the West Antarctic Ice Sheet, East Antarctic Ice Sheet, and local ice in the Transantarctic Mountains. The AND-2A drillhole reached a total depth of 1138.54 mbsf, and obtained an excellent quality core with 98% recovery through the cored interval. Stratigraphic sequences and facies interpretations reveal a cyclical history of environmental variation influenced by climate, glacial advance/retreat cycles, and water depth variation. These lower and middle Miocene shallow marine sediments were deposited in the subsiding Victoria Land Basin, during a period of relatively steady thermal subsidence, on the coastal plain and continental shelf seaward of the rising Transantarctic Mountains. A well-developed chronostratigraphic framework developed through integrated diatom biostratigraphy, magnetostratigraphy, Sr isotope geochemistry, and radiometric dating of volcanic materials, allows for the comparison of events recognized in this drillcore with events identified in distal proxy records from deep-sea stable isotope studies, and in sea-level reconstructions based on continental shelf sequence stratigraphy. More than 60 sequences recognized in the AND-2A drillcore represent repeating lithological changes in glacimarine, terrigenous, volcanic and biogenic sediments, deposited during a dynamic climate regime, that appear to reflect a variable pace of Milankovitch forcing.

  13. Hydrogeology and Physical Characteristics of Water Samples at the Red River Aluminum Site, Stamps, Arkansas

    NASA Astrophysics Data System (ADS)

    Czarnecki, J. B.; Stanton, G. P.; Freiwald, D. A.

    2001-12-01

    The Red River Aluminum site near Stamps, Arkansas, contains waste piles of salt cake and metal byproducts from the smelting of aluminum. The waste piles are subjected to about 50 inches of rainfall a year, resulting in the dissolution of the salts and metal. To assess the potential threat to underlying ground-water resources at the site, its hydrogeology was characterized by measuring water levels and field parameters of water quality in 23 wells and at 2 surface-water sites. Seventeen of these monitor wells were constructed at various depths for this study to allow for the separate characterization of the shallow and deep ground-water systems, the calculation of vertical gradients, and the collection of water samples at different depths within the flow system. Lithologic descriptions from drill-hole cuttings and geophysical logs indicate the presence of interbedded sands, gravels, silts, and clays to depths of 65 feet. The regionally important Sparta aquifer underlies the site. Water levels in shallow wells indicate radial flow away from the salt-cake pile located near the center of the site. Flow in the deep system is to the west and southwest toward Bodcau Creek. Water-level data from eight piezometer nests indicate a downward hydraulic gradient from the shallow to deep systems across the site. Values of specific conductance (an indicator of dissolved salts) ranged from 215 to 196,200 microsiemens per centimeter and indicate that saline waters are being transported horizontally and vertically downward away from the site.

  14. A novel application of the ESR method: dating of insular phosphorites and reef limestone

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Brumby, S.; Jacobson, G.; Beckwith, A. L. J.; Polach, H. A.

    Samples composed of cemented coral conglomerate, reef limestone, and phosphorite have been obtained from outcrops and two drillholes on Nauru Island, central Pacific Ocean. They have been used to test the ESR dating method as applied to insular phosphorite and reef limestone, up to several million years in age. The following time framework for the diagenesis and recrystallisation of the deposits was obtained: 0.08-0.10 Ma for superficial phosphatic crust; 0.18-0.22 Ma for massive phosphorite with nodules and replaced coral; 0.50-0.60 Ma for uppermost reef limestone; 1.00-2.00 Ma for reef limestone at a depth of about 15 m; 3.00-5.00 Ma for reef limestone under the modern reef flat, perhaps extending to the interior upland at a depth of about 70-80 m. These ages are consistent with the stratigraphic positions and geological estimations, thus demonstrating that both phosphatic deposits and reef limestone are suitable for ESR dating. The age limination for reef limestone specimens may be more than 3-4 million years.

  15. Flexible Mechanical Conveyors for Regolith Extraction and Transport

    NASA Technical Reports Server (NTRS)

    Walton, Otis R.; Vollmer, Hubert J.

    2013-01-01

    A report describes flexible mechanical conveying systems for transporting fine cohesive regolith under microgravity and vacuum conditions. They are totally enclosed, virtually dust-free, and can include enough flexibility in the conveying path to enable an expanded range of extraction and transport scenarios, including nonlinear drill-holes and excavation of enlarged subsurface openings without large entry holes. The design of the conveyors is a modification of conventional screw conveyors such that the central screw-shaft and the outer housing or conveyingtube have a degree of bending flexibility, allowing the conveyors to become nonlinear conveying systems that can convey around gentle bends. The central flexible shaft is similar to those used in common tools like a weed whacker, consisting of multiple layers of tightly wound wires around a central wire core. Utilization of compliant components (screw blade or outer wall) increases the robustness of the conveying, allowing an occasional oversized particle to pass hough the conveyor without causing a jam or stoppage

  16. Evaluation of the geothermal resource in the area of Albuquerque, New Mexico

    SciTech Connect

    Jiracek, G.R.; Swanberg, C.A.; Morgan, P.; Parker, M.D.

    1983-07-01

    Factors indicating a potential geothermal resource near Albuquerque are: (1) nearby volcanoes active as recently as 120,000 years ago, (2) gravity interpretation indicating a potential reservoir averaging 1.5 km thickness, (3) high heat flow near the city, (4) warm waters (>30/sup 0/C) in municipal wells, (5) recent seismicity indicating active faulting, thereby, allowing the possibility of deep hydrothermal circulation, (6) high shallow (<30 m) temperature gradients (>100/sup 0/C/km) discovered in our drillholes, (7) deeper (<500 m) gradients from water wells exceeding 80/sup 0/C/km, and (8) chemical analyses of 88 groundwater samples yielding estimated base reservoir temperatures as high as 190/sup 0/C. An area of elevated shallow temperature gradients (less than or equal to 140/sup 0/C/km) was discovered a few kilometers west of Albuquerque by our 69 hole drilling program. Resistivity, magnetic, and gravity measurements combined with computer modeling suggests that heated ground water is forced closer to the surface here by flow over a buried ridge. A well drilled nearby yielded the highest recorded temperature in the Albuquerque area at its maximum depth (32.8/sup 0/C at 364 m). The deep gradient is 35/sup 0/C/km. An oil test well close by reported large volumes of water at 1 km; therefore, the possibility of a low temperature (>50/sup 0/C) geothermal resource exists west of Albuquerque at less than 1 km depth.

  17. Clastic rocks associated with the Midcontinent rift system in Iowa

    USGS Publications Warehouse

    Anderson, Raymond R.; McKay, Robert M.

    1997-01-01

    The Middle Proterozoic Midcontinent Rift System (MRS) of North America is a failed rift that formed in response to region-wide stresses about 1,100 Ma. In Iowa, the MRS is buried beneath 2,200?3,500 ft of Paleozoic and Mesozoic sedimentary rocks and Quaternary glaciogenic deposits. An extremely large volume of sediments was deposited within basins associated with the rift at several stages during its development. Although the uplift of a rift-axial horst resulted in the erosional removal of most of these clastic rocks from the central region of the MRS in Iowa, thick sequences are preserved in a series of horst-bounding basins. Recent studies incorporating petrographic analysis, geophysical modeling, and other analytical procedures have led to the establishment of a preliminary stratigraphy for these clastic rocks and interpretations of basin geometries. This information has allowed the refinement of existing theories and history of MRS formation in Iowa. Additionally, drill samples previously interpreted as indicating the existence of early Paleozoic basins overlying the Proterozoic MRS basins were re-examined. Samples previously interpreted as deep-lying Paleozoic rocks are now known to have caved from upper levels of the drillhole and were out of stratigraphic position. No deep Paleozoic basins exist in this area. These investigations led to the development of petrographic parameters useful in differentiating the Proterozoic MRS Red clastics from Paleozoic clastic rocks having similar lithologies.

  18. The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering

    PubMed Central

    Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A.; Janeczek, Agnieszka A.; Kontouli, Nasia; Kanczler, Janos M.; Evans, Nicholas D.; Oreffo, Richard OC

    2016-01-01

    Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p < 0.01). This human-avian system offers a simple refinement model for animal research and a step towards a humanized in vivo model for tissue engineering. PMID:27577960

  19. Task 3: Evaluation of mineral resource potential, caldera geology, and volcano-tectonic framework at and near Yucca Mountain

    SciTech Connect

    Weiss, S.I.; Noble, D.C.; Larson, L.T.

    1994-12-31

    This report summarizes the work of Task 3 that was initially discussed in our monthly reports for the period October 1, 1993 through September 30, 1994, and is contained in our various papers and abstracts, both published and in press or currently in review. Our efforts during this period have involved the continuation of studies begun prior to October, 1993, focussed mainly on aspects of the caldera geology, magmatic activity, hydrothermal mineralization and extensional tectonics of the western and central parts of the southwestern Nevada volcanic field (SWNVF), studies of the subsurface rocks of Yucca Mountain utilizing drill-hole sampled obtained in 1991 and 1992, and studies of veins and siliceous ledges cropping out in northwestern Yucca Mountain. These veins and ledges provide evidence for near-surface hydrothermal activity in northwestern Yucca Mountain during the Crater Flat Tuff period of volcanism. During the period of this report we have concentrated our efforts on the production and publication of documents summarizing many of the data, interpretations and conclusions of Task 3 studies pertaining to hydrothermal activity and mineralization in the Yucca Mountain region and their relations to volcanism and tectonic activity. The resulting two manuscripts for journal publication and a compilation of radiometric age and trace-element geochemical data are appended to this report.

  20. A Hydrostratigraphic Model of the Pahute Mesa - Oasis Valley Area, Nye County, Nevada

    SciTech Connect

    S. L. Drellack, Jr.; L. B. Prothro; J. L. Gonzales

    2001-12-01

    A 3-D hydrostratigraphic framework model has been built for the use of hydrologic modelers who are tasked with developing a model to determine how contaminants are transported by groundwater flow in an area of complex geology. The area of interest includes Pahute Mesa, a former nuclear testing area at the Nevada Test Site (NTS), and Oasis Valley, a groundwater discharge area down-gradient from contaminant source areas on Pahute Mesa. To build the framework model, the NTS hydrogeologic framework was integrated with an extensive collection of drill-hole data (stratigraphic, lithologic, and alteration data); a structural model; and several recent geophysical, geological, and hydrological studies to formulate a hydrostratigraphic system. The authors organized the Tertiary volcanic units in the study area into 40 hydrostratigraphic units that include 16 aquifers, 13 confining units, and 11 composite units. The underlying pre-Tertiary rocks were divided into six hydrostratigraphic units, including two aquifers and four confining units. The model depicts the thickness, extent, and geometric relationships of these hydrostratigraphic units (''layers'' in the model) along with all the major structural features that control them, including calderas and faults. The complexity of the model area and the non-uniqueness of some of the interpretations incorporated into the base model made it necessary to address alternative interpretations for some of the major features in the model. Six of these alternatives were developed so they could be modeled in the same fashion as the base model.

  1. Report on Conceptual Systems Analysis of Drilling Systems for 200-m-Depth Penetration and Sampling of the Martian Subsurface

    NASA Astrophysics Data System (ADS)

    Blacic, J. D.; Dreesen, D. S.; Mockler, T.

    2000-10-01

    A conceptual systems analysis study was performed to identify critical issues and assess the best technologies for accessing and sampling the Martian subsurface to a depth of 200 m.To illustrate what a credible system might look like for this mission, three example systems SYSTEMS were constructed from the analysis combining the best subsystems for rock comminution, drill-hole conveyance of subassemblies, drill-cuttings transport and disposal, well bore stabilization, power transmission from surface to hole bottom, and thermal management. Familiar cuttings transport methods are inefficient and possibly ineffective at shallow, near-vacuum wellbore pressure. Therefore, continuous coring was found to be feasible and probably the most efficient method to remove material from the bore, and so all samples were assumed to be of this form. The example systems are described conceptually and total system estimates for mass and power are given. We conclude that the assumed mass and power mission constraints are feasible. The analysis concludes with recommendations for subsystem research and prototype demonstrations that must be performed before any detailed mission design can be undertaken.

  2. Primary sedimentary structures and the internal architecture of a Martian sand body in search of evidence for sand transport and deposition

    NASA Technical Reports Server (NTRS)

    Basu, Abhijit

    1988-01-01

    Lunar experiences show that unmanned sample return missions, despite limitations on sample size, can produce invaluable data to infer crustal processes, regolith processes, regolith-atmosphere/ionosphere interaction processes, etc. Drill cores provide a record of regolith evolution as well as a more complete sample of the regolith than small scoops and/or rakes. It is proposed that: (1) a hole be drilled in a sand body to obtain continuous oriented cores; a depth of about 10 m would be compatible with what we know of bed form hierarchy of terrestrial stream deposits; (2) two trenches, at right angles to each other and close to the drill-hole, be dug and the walls scraped lightly such that primary/internal sedimentary structures of the sand body become visible; (3) the walls of the trenches be made gravitationally stable by impregnation techniques; (4) acetate or other peels of a strip on each wall be taken; and (5) appropriately scaled photographs of the walls be taken at different sun-angles to ensure maximum ease of interpretation of sedimentary structures; and, to correlate these structural features with those in the core at different depth levels of the core.

  3. The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering.

    PubMed

    Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A; Janeczek, Agnieszka A; Kontouli, Nasia; Kanczler, Janos M; Evans, Nicholas D; Oreffo, Richard Oc

    2016-01-01

    Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p < 0.01). This human-avian system offers a simple refinement model for animal research and a step towards a humanized in vivo model for tissue engineering. PMID:27577960

  4. Heat flow and geothermal assessment of the Escalante Desert, southwestern Utah, with emphasis on the Newcastle KGRA

    SciTech Connect

    Clement, M.D.; Chapman, D.S.

    1981-02-01

    Twenty-five new regional heat flow measurements are presented for the Escalante Desert region within the Great Basin of the western US. Heat flow excluding geothermal areas ranges from 42 to 350 mW m/sup -2/ but much of the variability may be caused by deeply circulating groundwater redistributing the regional flux. A subset of 10 sites drilled specifically to characterize the heat flow of the region yielded a mean of 100 mW m/sup -2/ with a standard deviation of 22 mW m/sup -2/. An analysis of thermal conductivities of solid cylindrical discs and rock chips of rhyolite to andesite tuffs emphasized the importance of porosity corrections to thermal conductivity measurements. A blind geothermal system southwest of Newcastle, Utah, situated within the Escalante Desert has also been studied. Heat flow results from 11 local drillholes yield values between 163 and 3065 mW m/sup -2/. The 500 mW m/sup -2/ contour encloses an area of 9.4 km/sup 2/. By integrating the anomalous flux above background over the thermal anomaly, a thermal power loss of 12.8 mW and corresponding subsurface mass discharge of 32 kg s/sup -1/ are calculated for this geothermal system.

  5. Hydrogeology and physical characteristics of water samples at the Red River aluminum site, Stamps, Arkansas, April 2001

    USGS Publications Warehouse

    Czarnecki, John B.; Stanton, Gregory P.; Freiwald, David A.

    2001-01-01

    The Red River Aluminum site near Stamps, Arkansas, contains waste piles of salt cake and metal byproducts from the smelting of aluminum. The waste piles are subjected to about 50 inches of rainfall a year, resulting in the dissolution of the salts and metal. To assess the potential threat to underlying ground-water resources at the site, its hydrogeology was characterized by measuring water levels and field parameters of water quality in 23 wells and at 2 surface-water sites. Seventeen of these monitor wells were constructed at various depths for this study to allow for the separate characterization of the shallow and deep ground-water systems, the calculation of vertical gradients, and the collection of water samples at different depths within the flow system. Lithologic descriptions from drill-hole cuttings and geophysical logs indicate the presence of interbedded sands, gravels, silts, and clays to depths of 65 feet. The regionally important Sparta aquifer underlies the site. Water levels in shallow wells indicate radial flow away from the salt-cake pile located near the center of the site. Flow in the deep system is to the west and southwest toward Bodcau Creek. Water-level data from eight piezometer nests indicate a downward hydraulic gradient from the shallow to deep systems across the site. Values of specific conductance (an indicator of dissolved salts) ranged from 215 to 196,200 microsiemens per centimeter and indicate that saline waters are being transported horizontally and vertically downward away from the site

  6. Nature of basement rocks under the Los Angeles Basin, southern California, as inferred from aeromagnetic data

    SciTech Connect

    Langenheim, V.E.; Jachens, R.C. . Branch of Geophysics)

    1993-04-01

    The Los Angeles (L.A.) Basin, one of the world's richest oil-producing basins, is underlain by at least two basement assemblages. Because the thickness of the basin sediments reaches up to a minimum of 10 km, magnetic data allow a more regional view of the juxtaposition and nature of basement rocks than do available drill-hole data. Aeromagnetic data indicate that a zone of magnetic rocks extends along the coast east of the Newport-Inglewood fault zone from the San Joaquin Hills northwest to the Santa Monica Mountains. The magnetic highs produced by these rocks appear to be a continuation of intense magnetic highs that are present over exposed rocks of the Peninsular Ranges batholith to the southwest. Modeling of a 180 nT magnetic high over the San Joaquin Hills indicates that the tops of two concealed magnetic sources are at about 1.5 km and 4.5 km depth, which places these bodies at or beneath the basement surface. Modeling of magnetic highs over the exposed batholithic rocks to the south reveals a source with similar geometry and magnetic properties. The associated gravity highs of the San Joaquin Hills suggest that the probable lithology of these concealed magnetic bodies is a dense crystalline rock such as gabbro.

  7. Uncertainty Analysis for Assessing Leakage Through Water Tunnels: A Case from Nepal Himalaya

    NASA Astrophysics Data System (ADS)

    Panthi, Krishna Kanta; Nilsen, Bjørn

    2010-09-01

    Water leakage problems in unlined or shotcrete lined water tunnels are not new issues. In many occasions severe water leakage problems have been faced that not only have reduced the stability of the rock mass, but also have caused valuable water to be lost from it, causing safety risk as well as huge economic loss to the projects. Hence, making tunnels water tight plays an important role in improving stability and safety of underground excavations. The real challenge is however accurate prediction and quantification of possible water leakage, so that cost consequences can be incorporated during planning of a water conveying tunnel project. The main purposes of this paper are to analyze extensive data on leakage test carried out through exploratory drillhole used to define the need for pre-injection grouting of Khimti headrace tunnel and to carry out probabilistic approach of uncertainty analysis based on relationship established between leakage, hydrostatic head and selected Q-value parameters. The authors believe that the new approach regarding uncertainty analysis of leakage presented in this paper will improve the understanding of leakage characteristics of the rock mass, and hope this will lead to a better understanding concerning quantification of possible water leakage from unlined and shotcrete lined water tunnels.

  8. Chlorine isotopic compositions of deep saline fluids in Ibusuki coastal geothermal region, Japan: using B-Cl isotopes to interpret fluid sources.

    PubMed

    Musashi, Masaaki; Oi, Takao; Kreulen, Rob

    2015-01-01

    We report chlorine stable isotopic compositions (δ(37)Cl, expressed in ‰ relative to the standard mean ocean chloride) as well as δ(2)H and δ(18)O values of deep saline fluids taken at eight drill-holes reaching from 73 to 780 m below sea level in the Ibusuki coastal geothermal region, Japan. Analytical results show that the δ(37)Cl values narrowly range between -0.26 and +0.21 ‰ with an analytical precision of ±0.06 ‰. Except for one sample, the samples examined are negative in δ(37)Cl value with varying Cl/B molar ratios from 117 to 1265. A correlation study between the Cl/B molar ratio and the δ(37)Cl/δ(11)B ratio indicates a hyperbola-type mixing of at least two Cl sources in the Ibusuki region. One of them depletes in (37)Cl with a higher value of Cl/B molar ratio; and the other one enriches in (37)Cl with a lower Cl/B molar ratio. The former is chemically identical to that of the deep brine, which is altered seawater through the seawater-hot rock interaction. The latter is chemically similar to gas condensate derived from the high-temperature (890 °C) vent of an island-arc volcano near the Ibusuki region. PMID:25564103

  9. Structural style of east flank of Bighorn Mountains, Johnson and Sheridan Counties, Wyoming

    SciTech Connect

    Furner, R.B. )

    1989-09-01

    The 70 mi-long portion of the east flank of the Bighorn Mountains, between Sheridan and Mayoworth, Wyoming, is structurally divisible into three distinct segments - northern, central, and southern - each distinguished by a dominant sense of vergence and structural style. The northern segment displays southwest-verging reverse faults and associated folds, indicating tectonic transport out of the Powder River basin and onto the mountain flank. The central segment displays northeast and east-northeast-verging reverse faults and associated folds, indicating tectonic transport of the mountain flank over the Powder River basin. Seismic and drill-hole data indicate most of these reverse faults dip to the southwest and west-southwest at angles of 35{degree} or less. The southern segment displays west-southwest-verging reverse faults and associated folds, again indicating tectonic transport out of the Powder River basin and onto the mountain flank. All major structures identified within the area of investigation are basement involved, and the geometry of the rocks supports the concept that the mountain flank deformed under the influence of northeast-southwest-directed horizontal compression rather than vertically oriented block uplift.

  10. Geology of the Ferron Sandstone coalbed gas [open quotes]fairway,[close quotes] central Utah

    SciTech Connect

    Tabet, D.E.; Hucka, B.P.; Sommer, S.N. )

    1996-01-01

    A major new coalbed gas play with as many as 1,000 wells already proposed is being developed in the Upper Cretaceous Ferron Sandstone of central Utah. The Ferron consists of a vertically stacked sequence of as many as seven fluvial-deltaic sandstones and laterally equivalent interdistributary coal swamp units. A new total-net-coal isopach map for the Ferron, compiled from the review of hundreds of well records, shows the greatest accumulation of coal generally occurs in a 6-to 10-mile-wide band, or fairway, directly to the west (landward) of the fluvial-deltaic sandstones. This fairway can be traced a distance of at least 80 miles, heading southwest from the vicinity of Price to the southeast corner of Sevier County. The fairway is interrupted roughly every 8-to-12 miles along its length by deltaic, distributary-channel systems. Well samples of Ferron coal were examined microscopically to determine vitrinite reflectance and maturity level. Near-surface coals, on the east side of the fairway, have vitrinite reflectance measurements as low as 0.5 percent. Reflectance values increase to the west, reaching a maximum of 0.71 percent. The maturity of coals with vitrinite reflectance readings between 0.5 and 0.71 percent is the early stage in which thermogenic methane generation begins. Examination of drill-hole data also shows that the coal fairway exists at shallow to moderate depths, ranging from surface exposures to 8,000 feet deep.

  11. Geology of the Ferron Sandstone coalbed gas {open_quotes}fairway,{close_quotes} central Utah

    SciTech Connect

    Tabet, D.E.; Hucka, B.P.; Sommer, S.N.

    1996-12-31

    A major new coalbed gas play with as many as 1,000 wells already proposed is being developed in the Upper Cretaceous Ferron Sandstone of central Utah. The Ferron consists of a vertically stacked sequence of as many as seven fluvial-deltaic sandstones and laterally equivalent interdistributary coal swamp units. A new total-net-coal isopach map for the Ferron, compiled from the review of hundreds of well records, shows the greatest accumulation of coal generally occurs in a 6-to 10-mile-wide band, or fairway, directly to the west (landward) of the fluvial-deltaic sandstones. This fairway can be traced a distance of at least 80 miles, heading southwest from the vicinity of Price to the southeast corner of Sevier County. The fairway is interrupted roughly every 8-to-12 miles along its length by deltaic, distributary-channel systems. Well samples of Ferron coal were examined microscopically to determine vitrinite reflectance and maturity level. Near-surface coals, on the east side of the fairway, have vitrinite reflectance measurements as low as 0.5 percent. Reflectance values increase to the west, reaching a maximum of 0.71 percent. The maturity of coals with vitrinite reflectance readings between 0.5 and 0.71 percent is the early stage in which thermogenic methane generation begins. Examination of drill-hole data also shows that the coal fairway exists at shallow to moderate depths, ranging from surface exposures to 8,000 feet deep.

  12. Three-Dimensional Geologic Model of Complex Fault Structures in the Upper Seco Creek Area, Medina and Uvalde Counties, South-Central Texas

    USGS Publications Warehouse

    Pantea, Michael P.; Cole, James C.; Smith, Bruce D.; Faith, Jason R.; Blome, Charles D.; Smith, David V.

    2008-01-01

    This multimedia report shows and describes digital three-dimensional faulted geologic surfaces and volumes of the lithologic units of the Edwards aquifer in the upper Seco Creek area of Medina and Uvalde Counties in south-central Texas. This geologic framework model was produced using (1) geologic maps and interpretations of depositional environments and paleogeography; (2) lithologic descriptions, interpretations, and geophysical logs from 31 drill holes; (3) rock core and detailed lithologic descriptions from one drill hole; (4) helicopter electromagnetic geophysical data; and (5) known major and minor faults in the study area. These faults were used because of their individual and collective effects on the continuity of the aquifer-forming units in the Edwards Group. Data and information were compared and validated with each other and reflect the complex relationships of structures in the Seco Creek area of the Balcones fault zone. This geologic framework model can be used as a tool to visually explore and study geologic structures within the Seco Creek area of the Balcones fault zone and to show the connectivity of hydrologic units of high and low permeability between and across faults. The software can be used to display other data and information, such as drill-hole data, on this geologic framework model in three-dimensional space.

  13. Comparative mineral chemistry and textures of SAFOD fault gouge and damage-zone rocks

    USGS Publications Warehouse

    Moore, Diane E.

    2014-01-01

    Creep in the San Andreas Fault Observatory at Depth (SAFOD) drillhole is localized to two foliated gouges, the central deforming zone (CDZ) and southwest deforming zone (SDZ). The gouges consist of porphyroclasts of serpentinite and sedimentary rock dispersed in a foliated matrix of Mg-smectite clays that formed as a result of shearing-enhanced reactions between the serpentinite and quartzofeldspathic rocks. The CDZ takes up most of the creep and exhibits differences in mineralogy and texture from the SDZ that are attributable to its higher shearing rate. In addition, a ∼0.2-m-wide sector of the CDZ at its northeastern margin (NE-CDZ) is identical to the SDZ and may represent a gradient in creep rate across the CDZ. The SDZ and NE-CDZ have lower clay contents and larger porphyroclasts than most of the CDZ, and they contain veinlets and strain fringes of calcite in the gouge matrix not seen elsewhere in the CDZ. Matrix clays in the SDZ and NE-CDZ are saponite and corrensite, whereas the rest of the CDZ lacks corrensite. Saponite is younger than corrensite, reflecting clay crystallization under declining temperatures, and clays in the more actively deforming portions of the CDZ have better equilibrated to the lower-temperature conditions.

  14. Heat flow and subsurface temperature as evidence for basin-scale ground-water flow, North Slope of Alaska

    USGS Publications Warehouse

    Deming, D.; Sass, J.H.; Lachenbruch, A.H.; De Rito, R. F.

    1992-01-01

    Several high-resolution temperature logs were made in each of 21 drillholes and a total of 601 thermal conductivity measurements were made on drill cuttings and cores. Near-surface heat flow (??20%) is inversely correlated with elevation and ranges from a low of 27 mW/m2 in the foothills of the Brooks Range in the south, to a high of 90 mW/m2 near the north coast. Subsurface temperatures and thermal gradients estimated from corrected BHTs are similarly much higher on the coastal plain than in the foothills province to the south. Significant east-west variation in heat flow and subsurface temperature is also observed; higher heat flow and temperature coincide with higher basement topography. The observed thermal pattern is consistent with forced convection by a topographically driven ground-water flow system. Average ground-water (Darcy) velocity in the postulated flow system is estimated to be of the order of 0.1 m/yr; the effective basin-scale permeability is estimated to be of the order of 10-14 m2. -from Authors

  15. Preferred orientation and elastic anisotropy in shales.

    SciTech Connect

    Lonardelli, I.; Wenk, H.-R.; Ren, Y.; Univ. of California at Berkeley

    2007-03-01

    Anisotropy in shales is becoming an important issue in exploration and reservoir geophysics. In this study, the crystallographic preferred orientation of clay platelets that contributes to elastic anisotropy was determined quantitatively by hard monochromatic X-ray synchrotron diffraction in two different shales from drillholes off the coast of Nigeria. To analyze complicated diffraction images with five different phases (illite/smectite, kaolinite, quartz, siderite, feldspar) and many overlapping peaks, we applied a methodology based on the crystallographic Rietveld method. The goal was to describe the intrinsic physical properties of the sample (phase composition, crystallographic preferred orientation, crystal structure, and microstructure) and compute macroscopic elastic properties by averaging single crystal properties over the orientation distribution for each phase. Our results show that elastic anisotropy resulting from crystallographic preferred orientation of the clay particles can be determined quantitatively. This provides a possible way to compare measured seismic anisotropy and texture-derived anisotropy and to estimate the contribution of the low-aspect ratio pores aligned with bedding.

  16. Interpretation of gravity data using 2-D continuous wavelet transformation and 3-D inverse modeling

    NASA Astrophysics Data System (ADS)

    Roshandel Kahoo, Amin; Nejati Kalateh, Ali; Salajegheh, Farshad

    2015-10-01

    Recently the continuous wavelet transform has been proposed for interpretation of potential field anomalies. In this paper, we introduced a 2D wavelet based method that uses a new mother wavelet for determination of the location and the depth to the top and base of gravity anomaly. The new wavelet is the first horizontal derivatives of gravity anomaly of a buried cube with unit dimensions. The effectiveness of the proposed method is compared with Li and Oldenburg inversion algorithm and is demonstrated with synthetics and real gravity data. The real gravity data is taken over the Mobrun massive sulfide ore body in Noranda, Quebec, Canada. The obtained results of the 2D wavelet based algorithm and Li and Oldenburg inversion on the Mobrun ore body had desired similarities to the drill-hole depth information. In all of the inversion algorithms the model non-uniqueness is the challenging problem. Proposed method is based on a simple theory and there is no model non-uniqueness on it.

  17. New oil source rocks cut in Greek Ionian basin

    SciTech Connect

    Karakitsios, V.; Rigakis, N.

    1996-02-12

    The Ionian zone of Northwest Greece (Epirus region) constitutes part of the most external zones of the Hellenides (Paxos zone, Ionian zone, Gavrovo Tripolitza zone). The rocks of the Ionian zone range from Triassic evaporites and associated breccias through a varied series of Jurassic through Upper Eocene carbonates and lesser cherts and shales followed by Oligocene flysch. The surface occurrences of petroleum in the Ionian zone are mainly attributed to Toarcian Lower Posidonia beds source rocks and lesser to late Callovian-Tithonian Upper Posidonia beds and to the Albian-Cenomanian Upper Siliceous zone or Vigla shales of the Vigla limestones. Oil that could not be attributed to the above source rocks is believed to have an origin from Triassic formations that contain potential source rocks in Albania and Italy. However, several samples of the shales of Triassic breccias from outcrops and drillholes were analyzed in the past, but the analytical results were not so promising since their hydrocarbon potential was low. In this article, the authors will present their analytical results of the Ioannina-1 well, where for the first time they identified some very rich source beds in the Triassic breccias formation of Northwest Greece.

  18. Erschließung eines Marmorkarstvorkommens als mitteltiefer Erdwärmesondenspeicher im Tuxertal, Tirol

    NASA Astrophysics Data System (ADS)

    Sass, Ingo; Heldmann, Claus-Dieter; Lehr, Clemens

    2016-05-01

    Borehole heat exchangers can be economically beneficial for meeting heating and cooling demands of houses or buildings. In karst aquifers development of thermal storage and exchange systems may be problematic in terms of groundwater protection and storage design, due to possibly high groundwater velocities. The new development of the Hochstegen marble unit in the Tux Valley (Zillertal, Austria) was designed in two stages for the requested cooling and heating demands. An enhanced geothermal response test was completed using optical frequency domain reflectometry in an exploration drillhole. Additional studies focussing on local geology and hydrology were also conducted. Geothermal parameters obtained at precise depths allowed differentiating between conductive and convective heat flow and were correlated with the lithostratigraphically-conditioned karst characteristics. The borehole heat exchanger field was developed with nine 400 m deep dual U-shaped tube probes in 2013 for 1 GWh/a extraction and 400 MWh/a induction. Along with borehole geophysics and geothermal response tests, the study has provided relevant geothermal data for improving storage design and exploration.

  19. Tectonic breccias--conduits for ore-bearing and metasomatic fluids in the Jabiluka unconformity-type uranium-gold deposit, Northern Territory, Australia

    SciTech Connect

    Nutt, C.J.; Grauch, R.I.

    1985-01-01

    The distribution of strata-bound uranium ore in the highly chloritized Early Proterozoic metasedimentary rocks at Jabiluka, Australia, is controlled by shear zones associated with repeated episodes of brittle deformation. Based on extensive study of drill-hole core, the authors proposed tectonic control of ore distribution contrasts with most previous Jabiluka models that emphasize carbonate solution and collapse as the primary cause of brecciation. The strata-bound character of the ore, which is predominantly in chlorite, chlorite+graphite, and siliceous breccias, is a function of the susceptibility of specific rock types to shear and fracture. The siliceous breccias, which may in part be preferentially brecciated and silicified magnesite and dolomite, commonly contain fragments of sheared and strained quartz in recrystallized quartz matrix. Mineralized schist fragments and broken uraninite veins in breccias indicate that some of the brecciation occurred after a major mineralizing event. Brecciated zones and fractures are cemented and filled by quartz and by Mg-rich chlorite and 7A amesite. The presence of at least three generations of quartz in siliceous breccias and a number of optically, and in some cases chemically, distinguishable chlorites in chlorite breccias indicates that repeated pulses of fluids moved through the broken rocks. The circulation of these fluids redistributed and possibly further concentrated preexisting ore.

  20. Bulk densities and porosities of Cenozoic and Cretaceous basin-filling strata and Cretaceous and older basement rocks, Los Angeles Basin, California, determined from measurements of core samples

    USGS Publications Warehouse

    Beyer, L.A.; McCulloh, T.H.

    1998-01-01

    This report describes and provides a digital data file of selected bulk properties of subsurface rocks sampled in and around Los Angeles basin, California. Selected properties include measured dry bulk density (range 0.78 to 3.01 g/cm3), measured or estimated grain (matrix) density, calculated water saturated bulk density (range 1.47 to 3.01 g/cm3), calculated total porosity (range 0 to 69 porosity percent), geologic age, and lithology. Most of the rocks are conventional core samples taken from wells drilled by the petroleum industry. A small percentage of the core samples are from shallow borings. Rocks studied range in age from pre-Cambrian (?) to Recent and include sedimentary (98.8%), and volcanic, metamorphic and intrusive (1.2%) samples. Core samples studied were taken from measured drillhole depths that range from 35 to 20,234 ft (11 to 6,167 m). Version 1.0 of the data base (dated June 1998) contains information for 7378 samples from 234 wells, including two redrilled wells. This report/data base can be accessed on U. S. Geological Survey servers at http://geopubs.wr.usgs.gov/open-file/of98-788. Periodic additions to the on-line data base will be provided as new data is gathered.

  1. Magnetotelluric data, Taos Plateau Volcanic Field, New Mexico

    USGS Publications Warehouse

    Ailes, Chad E.; Rodriguez, Brian D.

    2010-01-01

    The population of the San Luis Basin region of northern New Mexico is growing. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's groundwater resources. An important issue in managing the groundwater resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal groundwater aquifers. The shallow unconfined aquifer and the deeper confined Santa Fe Group aquifer in the San Luis Basin are the main sources of municipal water for the region. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey called magnetotellurics (MT), and hydrologic and lithologic data are being used to better understand the aquifers. This report describes a regional east-west MT sounding profile acquired in late July 2009 across the Taos Plateau Volcanic Field where drillhole data are sparse. Resistivity modeling of the MT data can be used to help map changes in electrical resistivity with depths that are related to differences in rock types. These various rock types help control the properties of aquifers. The purpose of this report is to release the MT sounding data collected along the east-west profile. No interpretation of the data is included.

  2. Texture development in naturally compacted and experimentally deformed silty clay sediments from the Nankai Trench and Forearc, Japan

    NASA Astrophysics Data System (ADS)

    Schumann, Kai; Stipp, Michael; Leiss, Bernd; Behrmann, Jan H.

    2014-12-01

    The petrophysical properties of fine-grained marine sediments to a large extent depend on the microstructure and crystallographic preferred orientations (CPOs). In this contribution we show that Rietveld-based synchrotron texture analysis is a new and valuable tool to quantify textures of water-saturated fine-grained phyllosilicate-rich sediments, and assess the effects of compaction and tectonic deformation. We studied the CPO of compositionally almost homogeneous silty clay drillcore samples from the Nankai Accretionary Prism slope and the incoming Philippine Sea plate, offshore SW Japan. Basal planes of phyllosilicates show bedding-parallel alignment increasing with drillhole depth, thus reflecting progressive burial and compaction. In some samples calcite and albite display a CPO due to crystallographically controlled non-isometric grain shapes, or nannofossil tests. Consolidated-undrained experimental deformation of a suite of thirteen samples from the prism slope shows that the CPOs of phyllosilicate and calcite basal planes develop normal to the experimental shortening axis. There is at least a qualitative relation between CPO intensity and strain magnitude. Scanning electron micrographs show concurrent evolution of preferred orientations of micropores and detrital illite flakes normal to axial shortening. This indicates that the microfabrics are sensitive strain gauges, and contribute to anisotropic physical properties along with the CPO.

  3. Clustering of downhole physical property measurements at the Victoria property, Sudbury for the purpose of extracting lithological information

    NASA Astrophysics Data System (ADS)

    Mahmoodi, Omid; Smith, Richard

    2015-07-01

    Downhole density, gamma radioactivity, and magnetic susceptibility measurements in five drillholes at the Victoria property (located in the south range of the Sudbury basin) were analyzed to identify homogenous physical units. The fuzzy k-means clustering algorithm was used for unsupervised classification of the data. Four main physical units were identified in boreholes with distinct physical characteristics. Three of them were differentiated mainly based on different gamma ray and density values, and the fourth one was characterized by high magnetic susceptibility. Physical units were compared with rock types logged by geologists to determine which rock types corresponded to physical units. We found that there was a meaningful spatial and statistical correlation between physical units (characterized based on their physical property measurements) and lithological units as indicated by rock types at the Victoria property. However, not all rock types could be uniquely identified by the statistical classification, but a set of similar groups could be identified. Hence, identifying a group of rock types described by each physical unit can be used to translate physical data to/from lithological data. Alternatively, the physical log units could be used as a quality control procedure to check the geological logs, or to highlight areas where more careful logging or other investigation would be warranted.

  4. Geospatial data for coal beds in the Powder River Basin, Wyoming and Montana

    USGS Publications Warehouse

    Kinney, Scott A.; Scott, David C.; Osmonson, Lee M.; Luppens, James A.

    2015-01-01

    The purpose of this report is to provide geospatial data for various layers and themes in a Geographic Information System (GIS) format for the Powder River Basin, Wyoming and Montana. In 2015, as part of the U.S. Coal Resources and Reserves Assessment Project, the U.S. Geological Survey (USGS) completed an assessment of coal resources and reserves within the Powder River Basin, Wyoming and Montana. This report is supplemental to USGS Professional Paper 1809 and contains GIS data that can be used to view digital layers or themes, including the Tertiary limit of the Powder River Basin boundary, locations of drill holes, clinker, mined coal, land use and technical restrictions, geology, mineral estate ownership, coal thickness, depth to the top of the coal bed (overburden), and coal reliability categories. Larger scale maps may be viewed using the GIS data provided in this report supplemental to the page-size maps provided in USGS Professional Paper 1809. Additionally, these GIS data can be exported to other digital applications as needed by the user. The database used for this report contains a total of 29,928 drill holes, of which 21,393 are in the public domain. The public domain database is linked to the geodatabase in this report so that the user can access the drill-hole data through GIS applications. Results of this report are available at the USGS Energy Resources Program Web site,http://energy.usgs.gov/RegionalStudies/PowderRiverBasin.aspx.

  5. Data regarding hydraulic fracturing distributions and treatment fluids, additives, proppants, and water volumes applied to wells drilled in the United States from 1947 through 2010

    USGS Publications Warehouse

    Gallegos, Tanya J.; Varela, Brian A.

    2015-01-01

    Comprehensive, published, and publicly available data regarding the extent, location, and character of hydraulic fracturing in the United States are scarce. The objective of this data series is to publish data related to hydraulic fracturing in the public domain. The spreadsheets released with this data series contain derivative datasets aggregated temporally and spatially from the commercial and proprietary IHS database of U.S. oil and gas production and well data (IHS Energy, 2011). These datasets, served in 21 spreadsheets in Microsoft Excel (.xlsx) format, outline the geographical distributions of hydraulic fracturing treatments and associated wells (including well drill-hole directions) as well as water volumes, proppants, treatment fluids, and additives used in hydraulic fracturing treatments in the United States from 1947 through 2010. This report also describes the data—extraction/aggregation processing steps, field names and descriptions, field types and sources. An associated scientific investigation report (Gallegos and Varela, 2014) provides a detailed analysis of the data presented in this data series and comparisons of the data and trends to the literature.

  6. Thermal maturity and source-rock potential in Northwestern Melville Island, Arctic Canada

    SciTech Connect

    Gentzis, T. ); Goodarzi, F. )

    1992-10-01

    This paper reports that approximately 130 core and drillhole cuttings samples taken from the Palaeozoic and Mesozoic of northwestern Melville Island were examined using reflected-light microscopy and Rock-Eval pyrolysis. The Palaeozoic section is dominated by bitumen, and often numerous bitumen populations are identified based on morphology, texture, and optical properties. Bitumen reflectance increases with depth, following a trend almost parallel to vitrinite, an indication that it is primary and has been subjected to similar thermal stress. The upper Palaeozoic sediments are within the hydrocarbon generation zone but have limited potential, except for an algal-rich interval in the Permian Trold Fiord Formation. Overall, the study is important because it attempts to identify the source rocks in an area of Melville Island where no previous work has been reported on the hydrocarbon-generating potential of the sedimentary succession. In addition, the use of bitumen reflectance in lower Palaeozoic strata devoid of vitrinite is evaluated and the amount of eroded section is calculated based on the thermal maturity pattern of bitumen.

  7. Thermal regime of the Escalante Desert, Utah, with an analysis of the the Newcastle Geothermal System

    SciTech Connect

    Chapman, D.S.; Clement, M.D.; Mase, C.W.

    1981-12-10

    Twenty-five new heat flow measurements are presented for the Escalante Desert region within the Great Basin of the wester United States. Heat flow, excluding geothermal areas, ranges from 43 to 350 mW m/sup -2/, but much of the variability may be caused by deeply circulating groundwater redistributing the regional flux. A subset of 10 sites drilled specifically to characterize the heat flow of the region yielded a mean of 100 mW m/sup -2/ with a standard deviation of 22 mW m/sup -2/. A comparison of thermal conductivities of solid cylindrical discs and rock chips (rhyolite to andesite tuffs) confirmed the importance of porosity corrections to thermal conductivity measurements. A 'blind' geothermal system southwest of Newastle, Utah, situated within the Escalante Desert, has also been studied. Temperature Desert, has also been studied. Temperatures of 110/sup 0/C are observed only 75 m below the ground surface. Heat flow results from 11 drillholes in this region yield values between 163 and 3065 mW m/sup -2/. The 500 mW m/sup -2/ contour encloses an area of 9.4 km/sup 2/. By integrating the excess heat flux (above background) over the thermal anomaly, we deduce a thermal power loss of 12.8 MW for this geothermal system, which corresponds to a subsurface water discharge of 32 kg s/sup -1/.

  8. Global change and the dynamics of ecological systems: Cretaceous through Oligocene naticid gastropods and their prey

    SciTech Connect

    Kelley, P.H. . Dept. of Geology and Geological Engineering); Hansen, T.A. . Dept. of Geology)

    1993-03-01

    Most studies of global change, particularly events that produced mass extinctions, document extinction and survivorship within taxonomic groups or trophic levels. Studies that consider effects of such events on ecological systems are less common. Global events nevertheless affect interaction of species; to predict the consequences of future global change, one must consider interactions within ecological systems. Vermeij has suggested that escalation involving adaptation to enemies has been a major theme of Phanerozoic life, but that such escalation has proceeded at highly variable rates depending on extrinsic events. He has predicted that escalation should be fostered by climatic warming, marine transgression, and high primary productivity. Mass extinctions involving global cooling, regression, or reduction in productivity should temporarily halt escalation, but rapid rebound may occur because post-crisis assemblages provide the raw material for escalation. A comprehensive survey (40,000 specimens) of naticid gastropod predation in the Coastal Plain Cretaceous through Oligocene supports this hypothesis. Drilling frequencies dropped at the K/T and E/O boundaries, which were marked by decreases in productivity and/or cooling. Drilling recovered very rapidly after these events, and in the Paleocene far exceeded Cretaceous drilling, reaching modern levels. This suggests the K/T extinction produced a major reorganization of the ecosystem. Other indicators of escalation (frequency of incomplete and multiple drillholes), however, do not correspond as neatly to global change. Nevertheless, results suggest that global change may be a major determinant of long-term evolutionary patterns, such as escalation.

  9. Derivation and calibration of semi-empirical gas geothermometers for Mahanagdong Geothermal Project, Philippines

    SciTech Connect

    Sanchez, D.R.

    1996-12-31

    The dissolved CO{sub 2}, H{sub 2}S, and H{sub 2} gases in Mahanagdong aquifer fluids are controlled by specific gas-mineral equilibria. At temperature range of 250 to 310 {degrees}C, CO{sub 2} is buffered by clinozoisite + K-feldspar + calcite + muscovite (illite) + quartz mineral assemblage. For H{sub 2}S and H{sub 2} dissolved gases, they are more likely buffered by pyrrhotite + pyrite + magnetite mineral assemblage at similar temperature range. Calibration of five Mahanagdong (MG) gas geothermometers is presented, three of which used CO{sub 2}, H{sub 2}S, and H{sub 2} concentration in steam. The remaining two use CO{sub 2}/H{sub 2} and H{sub 2}S/H{sub 2} ratios. The calibration is based on the relation between gas content of drillhole discharges and measured aquifer temperatures. After establishing the gas content in the aquifer, gas concentrations were computed in steam after adiabatic boiling to atmospheric condition (100 {degrees}C), to obtain gas geothermometry functions. These functions could also be used in evaluating fraction of steam condensation and temperature of phase separation. A demonstration given the Mahanagdong fumarole data, indicates that there is generally a fair relation between computed temperatures using Mahanagdong gas geothermometers and the actual field trend`s temperatures.

  10. Advances in downhole sampling of high temperature solutions

    SciTech Connect

    Bayhurst, G.K.; Janecky, D.R.

    1991-01-01

    A fluid sampler capable of sampling hot and/or deep wells has been developed at Los Alamos National Laboratory. In collaboration with Leutert Instruments, an off-the-shelf sampler design was modified to meet gas-tight and minimal chemical reactivity/contamination specifications for use in geothermal wells and deep ocean drillholes. This downhole sampler has been routinely used at temperatures up to 300{degrees}C and hole depths of greater than 5 km. We have tested this sampler in various continental wells, including Valles Caldera VC-2a and VC-2b, German KTB, Cajon Pass, and Yellowstone Y-10. Both the standard commercial and enhanced samplers have also been used to obtain samples from a range of depths in the Ocean Drilling Project's hole 504B and during recent mid-ocean ridge drilling efforts. The sampler has made it possible to collect samples at temperatures and conditions beyond the limits of other tools with the added advantage of chemical corrosion resistance.

  11. Downhole measurements in the AND-1B borehole, ANDRILL McMurdo Ice Shelf Project, Antarctica

    USGS Publications Warehouse

    Morin, R.; Williams, T.; Henrys, S.; Crosby, T.; Hansaraj, D.

    2007-01-01

    A comprehensive set of downhole measurements was collected in the AND-1B drillhole as part of the on-ice scientific programme defined for the McMurdo Ice Shelf (MIS) Project. Geophysical logs were recorded over two operation phases and consisted of calliper, temperature, fluid conductivity, induction resistivity, magnetic susceptibility, natural gamma activity, acoustic televiewer, borehole deviation, and dipmeter. In addition, two standard vertical seismic profiles (VSP) and one walk-away VSP were obtained. Radioactive logs (porosity and density) were not run because of unstable borehole conditions. Although the total depth of the hole is 1285 metres below seafloor (mbsf), the depth range for in situ measurements was limited by the length of the wireline (1018 mbsf) and by the nullification of some geophysical logs due to the presence of steel casing. A depth correction was derived to account for systematic discrepancies in depth between downhole measurements and cores; consequently, log responses can be directly compared to core properties. The resulting data are amenable to studies of cyclicity and climate, heat flux and fluid flow, and stricture and stress. When integrated with physical properties and fractures measured on the core, this information should play a significant role in addressing many of the scientific objectives of the ANDRILL programme.

  12. Tectonic events recorded in the sediments and crust of the Caribbean sea floor

    SciTech Connect

    Holcombe, T.L.

    1985-01-01

    A reconnaissance review of reflection-seismic sections from the Caribbean, together with limited information derived from dredged rocks, sediment cores, and drillholes, yields or contributes to first-order conclusions regarding the tectonic history of the water-covered Caribbean. Broadly speaking, tectonic episodes for which there is some evidence are: (1) late Cenozoic convergence and accretion along deformed continental or island margins off Panama, Colombia/Venezuela, and Hispaniola/Puerto Rico; (2) late Cenozoic generation of oceanic crust within the Cayman Trough; (3) late Cenozoic secondary deformation along the Caribbean-North American plate boundary zone, in the form of small pull-apart basins, transcurrent faults, tensional rift basins, and compressional features; (4) late Cenozoic slow disintegration of the western part of the Caribbean plate; (5) Cenozoic rift-basin formation on the upper Nicaraguan rise; (6) early Cenozoic or late Cretaceous opening of the Yucatan Basin; (7) late Cretaceous through early Cenozoic island arc formation; and (8) late Cretaceous and earlier emplacement of flow basalts in the northwestern Venezuelan Basin and possibly beneath large areas of the Caribbean. There is no evidence that except along their active margins, the Venezuelan Basin, Beata Ridge, Colombian Basin, and Nicaraguan rise areas have been sites for large-scale relative movements which created or destroyed plate material since late Cretaceous time - or earlier.

  13. The Erratic Behavior of Lesions in Burnt Bone.

    PubMed

    Collini, Federica; Amadasi, Alberto; Mazzucchi, Alessandra; Porta, Davide; Regazzola, Valeria Luisa; Garofalo, Paola; Di Blasio, Annalisa; Cattaneo, Cristina

    2015-09-01

    This study analyses depressed fractures (by blunt force trauma) and circular full-thickness injuries (drill injuries and gunshot wounds) in charred bones. Fifty bovine ribs (total 104 lesions) were divided into three groups. The first group consisted in 20 depressed hammer-produced fractures; in the second one, 60 round drill-holes were produced (30 circular, 30 semicircular); in the third group, 12 fleshed and 12 skeletonized ribs were hit by 9-mm bullets. Each specimen was carbonized in an electric oven up to 800°C. Morphological and metric analyses were performed before and after: morphological features were preserved, but depressed fractures showed an increase in their dimensions (p-value<0.05); the drilled holes shrunk (p-value<0.01); the charring cycle increased the number of fractures in samples with gunshot wounds differently in fleshed and defleshed ribs. This study showed the complex behavior of charred bone, for what concerns the interpretation of trauma and how caution should be applied. PMID:26257320

  14. Scientific drilling to study the roots of active hydrothermal systems related to young magmatic intrusions. [Abstract only

    SciTech Connect

    Muffler, L.J.P.

    1983-03-01

    At present, hydrothermal-magma processes can be studied only inferentially, using observations on hot springs and volcanic rocks, data from shallow- and intermediate-depth drill holes, analogies with exhumed fossil systems, and extrapolation of laboratory investigations. The Thermal Regimes Panel of the Continental Scientific Drilling Committee in a draft report concludes that an understanding of active hydrothermal-magma systems requires drill-hole investigations of deeper and hotter levels than have been drilled and studied to date. The Panel groups hydrothermal-magma systems in the United States into five classes: (1) dominantly andesitic centers, (2) spreading ridges, (3) basaltic fields, (4) evolved basaltic centers, and (5) silicic caldera complexes. Application of eight scientific criteria and three social criteria leads to the conclusion that silicic caldera complexes should be the first target of a focused drilling program to investigate the hydrothermal-magma interface at depths of 5 to 7 km. Primary targets are the three young, silicic caldera systems in the western conterminous United States: Yellowstone (Wyoming), Valles (New Mexico), and Long Valley (California). Scientific drilling of these active hydrothermal-magma systems complements scientific drilling proposed for fossil systems such as Creede (Colorado). In addition, the roots of the Salton Sea geothermal system (California) present an opportunity for add-on deep drilling and scientific experiments to supplement geothermal drilling by industry in this active spreading-ridge environment.

  15. Comparative mineral chemistry and textures of SAFOD fault gouge and damage-zone rocks

    NASA Astrophysics Data System (ADS)

    Moore, Diane E.

    2014-11-01

    Creep in the San Andreas Fault Observatory at Depth (SAFOD) drillhole is localized to two foliated gouges, the central deforming zone (CDZ) and southwest deforming zone (SDZ). The gouges consist of porphyroclasts of serpentinite and sedimentary rock dispersed in a foliated matrix of Mg-smectite clays that formed as a result of shearing-enhanced reactions between the serpentinite and quartzofeldspathic rocks. The CDZ takes up most of the creep and exhibits differences in mineralogy and texture from the SDZ that are attributable to its higher shearing rate. In addition, a ∼0.2-m-wide sector of the CDZ at its northeastern margin (NE-CDZ) is identical to the SDZ and may represent a gradient in creep rate across the CDZ. The SDZ and NE-CDZ have lower clay contents and larger porphyroclasts than most of the CDZ, and they contain veinlets and strain fringes of calcite in the gouge matrix not seen elsewhere in the CDZ. Matrix clays in the SDZ and NE-CDZ are saponite and corrensite, whereas the rest of the CDZ lacks corrensite. Saponite is younger than corrensite, reflecting clay crystallization under declining temperatures, and clays in the more actively deforming portions of the CDZ have better equilibrated to the lower-temperature conditions.

  16. Ant colony optimisation inversion of surface and borehole magnetic data under lithological constraints

    NASA Astrophysics Data System (ADS)

    Liu, Shuang; Hu, Xiangyun; Liu, Tianyou; Xi, Yufei; Cai, Jianchao; Zhang, Henglei

    2015-01-01

    The ant colony optimisation algorithm has successfully been used to invert for surface magnetic data. However, the resolution of the distributions of the recovered physical property for deeply buried magnetic sources is not generally very high because of geophysical ambiguities. We use three approaches to deal with this problem. First, the observed surface magnetic data are taken together with the three-component borehole magnetic anomalies to recover the distributions of the physical properties. This cooperative inversion strategy improves the resolution of the inversion results in the vertical direction. Additionally, as the ant colony tours the discrete nodes, we force it to visit the nodes with physical properties that agree with the drilled lithologies. These lithological constraints reduce the non-uniqueness of the inversion problem. Finally, we also implement a K-means cluster analysis for the distributions of the magnetic cells after each iteration, in order to separate the distributions of magnetisation intensity instead of concentrating the distribution in a single area. We tested our method using synthetic data and found that all tests returned favourable results. In the case study of the Mengku iron-ore deposit in northwest China, the recovered distributions of magnetisation are in good agreement with the locations and shapes of the magnetite orebodies as inferred by drillholes. Uncertainty analysis shows that the ant colony algorithm is robust in the presence of noise and that the proposed approaches significantly improve the quality of the inversion results.

  17. Role of fluid in the mechanism of formation of volcaniclastic and coherent kimberlite facies: a diamond perspective

    NASA Astrophysics Data System (ADS)

    Fedortchouk, Yana; Chinn, Ingrid

    2016-04-01

    Dissolution features on diamonds recovered from kimberlites vary depending on the dissolution conditions and can be used as a reliable proxy for volatiles and their role in kimberlite emplacement. Volatiles determine the mechanism of magma emplacement; variation in volatile content and CO2/CO2+H2O ratio may affect the geology of kimberlite bodies and formation of coherent vs. volcaniclastic kimberlite facies. Here we examine the evolution of a kimberlite system during ascent using the resorption morphology of its diamond population. We use 655 macro-diamonds from a complex kimberlite pipe in the Orapa kimberlite field (Botswana) to examine the role of volatiles in the formation of the three facies comprising this pipe: two coherent kimberlite facies (CKA and CKB) and one massive volcaniclastic facies (MVK). The diamonds come from three drillholes through each of the studied kimberlite facies. Separate diamond samples derived from 2 - 13 m intervals were combined into 40 m depth intervals for statistical purposes. Four independent morphological methods allowed us to reliably discriminate products of resorption in kimberlite magma from resorption in the mantle, and use the former in our study. We found that the proportion of diamonds with kimberlitic resorption is the lowest in CKA - 22%, medium in MVK - 50%, and highest in CKB - 73%, and it increases with depth in each of the drillholes. Each kimberlite facies shows its own style of kimberlite-induced resorption on rounded tetrahexahedron (THH) diamonds: glossy surfaces in MVK, rough corroded surfaces in CKB, and combination of glossy surfaces with chains of circular pits in CKA, where these pits represent the initial stages of development of corrosive features observed on CKB diamonds. Based on the results of our previous experimental studies we propose that resorption of MVK diamonds is a product of interaction with COH fluid, resorption of CKB diamonds is a product of interaction with a volatile

  18. Geologic mapping of Kentucky; a history and evaluation of the Kentucky Geological Survey--U.S. Geological Survey Mapping Program, 1960-1978

    USGS Publications Warehouse

    Cressman, Earle Rupert; Noger, Martin C.

    1981-01-01

    In 1960, the U.S. Geological Survey and the Kentucky Geological Survey began a program to map the State geologically at a scale of 1:24,000 and to publish the maps as 707 U.S. Geological Survey Geologic Quadrangle Maps. Fieldwork was completed by the spring of 1977, and all maps were published by December 1978. Geologic mapping of the State was proposed by the Kentucky Society of Professional Engineers in 1959. Wallace W. Hagan, Director and State Geologist of the Kentucky Geological Survey, and Preston McGrain, Assistant State Geologist, promoted support for the proposal among organizations such as Chambers of Commerce, industrial associations, professional societies, and among members of the State government. It was also arranged for the U.S. Geological Survey to supply mapping personnel and to publish the maps; the cost would be shared equally by the two organizations. Members of the U.S. Geological Survey assigned to the program were organized as the Branch of Kentucky Geology. Branch headquarters, including an editorial staff, was at Lexington, Ky., but actual mapping was conducted from 18 field offices distributed throughout the State. The Publications Division of the U.S. Geological Survey established a cartographic office at Lexington to prepare the maps for publication. About 260 people, including more than 200 professionals, were assigned to the Branch of Kentucky Geology by the U.S. Geological Survey at one time or another. The most geologists assigned any one year was 61. To complete the mapping and ancillary studies, 661 professional man-years were required, compared with an original estimate of 600 man-years. A wide variety of field methods were used, but most geologists relied on the surveying altimeter to obtain elevations. Surface data were supplemented by drill-hole records, and several dozen shallow diamond-drill holes were drilled to aid the mapping. Geologists generally scribed their own maps, with a consequent saving of publication costs

  19. Geophysical investigations of the Stuoragurra postglacial fault, Finnmark, northern Norway

    NASA Astrophysics Data System (ADS)

    Olesen, Odleiv; Henkel, Herbert; Lile, Ole Bernt; Mauring, Eirik; Rønning, Jan Steinar

    1992-08-01

    Processed images of aeromagnetic, gravimetric and topographical data and geological maps combined with VLF ground measurements have been interpreted in mapping the main fault structures along the Mierujav'ri-Sværholt Fault Zone (MSFZ) in Finnmark, northern Norway. The 230 km long MSFZ is situated in the extensive Proterozoic terrain of Finnmark. Proterozoic albite diabases, which cause characteristic magnetic anomalies in the Masi area, have intruded along the MSFZ. A system of duplexes can be delineated along the MSFZ from the geophysical images. These interpretations have been followed up in the till-covered area with electromagnetic measurements and confirm the existence of the faults interpreted from the geophysical images. The postglacial Stuoragurra Fault (SF) lies within the MSFZ. It is a southeasterly dipping reverse fault and can be traced fairly continuously for 80 km in the Masi-Iešjav'ri area. Detailed geophysical investigations and drilling have been carried out in the Fidnajåkka area 10 km to the south of Masi. A ca. 1 m thick layer of fault gouge detected in the drillholes is thought to represent the actual fault surface. Resistivity measurements reveal low-resistivity zones in the hanging-wall block as well as in the foot-wall block of the SF. These low-resistivity zones lie within a several hundred metre wide belt and are interpreted to be due to fracturing of the quartzites along the regional MSFZ. Within the Fidnajåkka area, however, the resistivity of the hanging-wall block of the SF is typically lower than in the foot-wall, indicating more intense fracturing in the hanging-wall. Vertical electrical soundings show a low-resistivity layer at depth in the eastern hanging-wall block, which corroborates other evidence that the fault dips to the southeast. The refraction seismic data reveal low seismic velocities along the SF which are interpreted to be caused by faulted and fractured bedrock. Detailed topographical data proved very useful for

  20. Magma chambers: Formation, local stresses, excess pressures, and compartments

    NASA Astrophysics Data System (ADS)

    Gudmundsson, Agust

    2012-09-01

    -situ tensile strength of the host rock, 0.5-9 MPa. These in-situ strength estimates are based on hydraulic fracture measurements in drill-holes worldwide down to crustal depths of about 9 km. These measurements do not support some recent magma-chamber stress models that predict (a) extra gravity-related wall-parallel stresses at the boundaries of magma chambers and (b) magma-chamber excess pressures prior to rupture of as much as hundreds of mega-pascals, particularly at great depths. General stress models of magma chambers are of two main types: analytical and numerical. Earlier analytical models were based on a nucleus-of-strain source (a 'point pressure source') for the magma chamber, and have been very useful for rough estimates of magma-chamber depths from surface deformation during unrest periods. More recent models assume the magma chamber to be axisymmetric ellipsoids or, in two-dimensions, ellipses of various shapes. Nearly all these models use the excess pressure in the chamber as the only loading (since lithostatic stress effects are then automatically taken into account), assume the chamber to be totally molten, and predict similar local stress fields. The predicted stress fields are generally in agreement with the world-wide stress measurements in drill-holes and, in particular, with the in-situ tensile-strength estimates. Recent numerical models consider magma-chambers of various (ideal) shapes and sizes in relation to their depths below the Earth's surface. They also take into account crustal heterogeneities and anisotropies; in particular the effects of the effects of a nearby free surface and horizontal and inclined (dipping) mechanical layering. The results show that the free surface may have strong effects on the local stresses if the chamber is comparatively close to the surface. The mechanical layering, however, may have even stronger effects. For realistic layering, and other heterogeneities, the numerical models predict complex local stresses around

  1. Application of fracture-flow hydrogeology to acid-mine drainage at the Bunker Hill Mine, Kellogg, Idaho

    NASA Astrophysics Data System (ADS)

    Lachmar, Thomas E.

    1994-03-01

    The mechanics of groundwater flow through fractured rock has become an object of major research interest during recent years. This project has investigated the flow of groundwater through fractured Precambrian metaquartzite rocks in a portion of the Bunker Hill Mine near Kellogg, Idaho. Groundwater flow through these types of rocks is largely dependent upon the properties of fractures such as faults, joints and relict bedding planes. Groundwater that flows into the mine via the fractures is acidic and is contaminated by heavy metals, which results in a severe acid mine drainage problem. A more complete understanding of how the fractures influence the groundwater flow system is a prerequisite of the evaluation of reclamation alternatives to reduce acid drainage from the mine. Fracture mapping techniques were used to obtain detailed information on the fracture properties observed in the New East Reed drift of the Bunker Hill Mine. The information obtained includes fracture type, orientation, trace length, the number of visible terminations, roughness, waviness, infilling material, and a qualitative measure of the amount of water flowing through each fracture. The hydrogeologic field data collected include routine measurements of the discharge from four individual structural features and four areas where large quantities of water are discharging from vertical rock bolts, the depths to water in three piezometer nests at the ground surface, the pressure variations in four diamond drillholes, and constant discharge flow tests conducted on three of the diamond drillholes. The field data indicate that relict bedding planes are the primary conduits for groundwater flow, and suggest that the two major joint sets that are present connect water flowing through the discontinuous bedding planes. The three minor joint sets that are present do not seem to have a significant impact on groundwater flow, but along with the two major joint sets may store relatively large quantities of

  2. Continuous monitoring of deep groundwater at the ice margin, Kangerlussuaq, West Greenland

    NASA Astrophysics Data System (ADS)

    Claesson Liljedahl, L.; Lehtinen, A. M.; Ruskeeniemi, T.; Engström, J.; Hansson, K.; Sundberg, J.; Henkemans, E.; Frape, S.; Johansson, S.; Acuna, J.

    2012-12-01

    The deep geologic repository (DGR) concept for the long-term management of used nuclear fuel involves the containment and isolation of used nuclear fuel at depths of approximately 500-1000 m below ground surface within a suitable geological formation for hundreds of thousands of years. A key objective of the used fuel DGR research programs of the Swedish, Finnish and Canadian nuclear waste management organizations (SKB, POSIVA and NWMO, respectively) is to further understanding of geosphere stability and long-term evolution. Future glaciation represents an intense external perturbation of a DGR situated in northern latitudes. To advance the understanding of processes associated with glaciation and their impact on the long-term performance of a DGR, the Greenland Analogue Project (GAP) was initiated by SKB, POSIVA and NWMO. The GAP was initiated in 2008 as a four-year field and modelling study utilizing the Greenland ice sheet and sub-surface conditions in West Greenland as an analogue for the conditions expected to prevail in Fennoscandia and Canada during future glacial cycles. One of the main aims of the GAP is to improve the understanding of how groundwater flow and water chemistry is influenced by an existing ice sheet and continuous permafrost. One way to study this is by monitoring deep drillholes. A 645 m deep drillhole (DH-GAP04) was drilled and instrumented in July 2011 at the ice-sheet margin in Kangerlussuaq, West Greenland to investigate the hydrogeochemical and hydrogeological conditions of a subglacial environment. Of particular interest is the recharge of glacial meltwater, and understanding to what depth it intrudes into the bedrock and whether it affects the chemistry and physico-chemical properties of the deep groundwater. DH-GAP04 is instrumented with a two-packer multi-sensor system, installed at a depth of 560 m, dividing the hole into three sections. The upper section extends from the base of permafrost (about 350 m) down to the upper packer

  3. The sub-ice platelet layer and its influence on freeboard to thickness conversion of Antarctic sea ice

    NASA Astrophysics Data System (ADS)

    Price, D.; Rack, W.; Langhorne, P. J.; Haas, C.; Leonard, G.; Barnsdale, K.

    2014-02-01

    This is an investigation to quantify the influence of the sub-ice platelet layer on satellite measurements of total freeboard and their conversion to thickness of Antarctic sea ice. The sub-ice platelet layer forms as a result of the seaward advection of supercooled ice shelf water from beneath ice shelves. This ice shelf water provides an oceanic heat sink promoting the formation of platelet crystals which accumulate at the sea ice-ocean interface. The build-up of this porous layer increases sea ice freeboard, and if not accounted for, leads to overestimates of sea ice thickness from surface elevation measurements. In order to quantify this buoyant effect, the solid fraction of the sub-ice platelet layer must be estimated. An extensive in situ data set measured in 2011 in McMurdo Sound in the south-western Ross Sea is used to achieve this. We use drill-hole measurements and the hydrostatic equilibrium assumption to estimate a mean value for the solid fraction of this sub-ice platelet layer of 0.16. This is highly dependent upon the uncertainty in sea ice density. We test this value with independent Global Navigation Satellite System (GNSS) surface elevation data to estimate sea ice thickness. We find that sea ice thickness can be overestimated by up to 19%, with a mean deviation of 12% as a result of the influence of the sub-ice platelet layer. It is concluded that in close proximity to ice shelves this influence should be considered universally when undertaking sea ice thickness investigations using remote sensing surface elevation measurements.

  4. The sub-ice platelet layer and its influence on freeboard to thickness conversion of Antarctic sea ice

    NASA Astrophysics Data System (ADS)

    Price, D.; Rack, W.; Langhorne, P. J.; Haas, C.; Leonard, G.; Barnsdale, K.

    2014-06-01

    This is an investigation to quantify the influence of the sub-ice platelet layer on satellite measurements of total freeboard and their conversion to thickness of Antarctic sea ice. The sub-ice platelet layer forms as a result of the seaward advection of supercooled ice shelf water from beneath ice shelves. This ice shelf water provides an oceanic heat sink promoting the formation of platelet crystals which accumulate at the sea ice-ocean interface. The build-up of this porous layer increases sea ice freeboard, and if not accounted for, leads to overestimates of sea ice thickness from surface elevation measurements. In order to quantify this buoyant effect, the solid fraction of the sub-ice platelet layer must be estimated. An extensive in situ data set measured in 2011 in McMurdo Sound in the southwestern Ross Sea is used to achieve this. We use drill-hole measurements and the hydrostatic equilibrium assumption to estimate a mean value for the solid fraction of this sub-ice platelet layer of 0.16. This is highly dependent upon the uncertainty in sea ice density. We test this value with independent Global Navigation Satellite System (GNSS) surface elevation data to estimate sea ice thickness. We find that sea ice thickness can be overestimated by up to 19%, with a mean deviation of 12% as a result of the influence of the sub-ice platelet layer. It is concluded that within 100 km of an ice shelf this influence might need to be considered when undertaking sea ice thickness investigations using remote sensing surface elevation measurements.

  5. High-resolution chemical composition of geothermal scalings from Hungary: Preliminary results

    NASA Astrophysics Data System (ADS)

    Boch, Ronny; Dietzel, Martin; Deák, József; Leis, Albrecht; Mindszenty, Andrea; Demeny, Attila

    2015-04-01

    Geothermal fluids originating from several hundreds to thousands meters depth mostly hold a high potential for secondary mineral precipitation (scaling) due to high total dissolved solid contents at elevated temperature and pressure conditions. The precipitation of e.g. carbonates, sulfates, sulfides, and silica has shown to cause severe problems in geothermal heat and electric power production, when clogging of drill-holes, downhole pumps, pipes and heat exchangers occurs (e.g. deep geothermal doublet systems). Ongoing scaling reduces the efficiency in energy extraction and might even question the abandonment of installations in worst cases. In an attempt to study scaling processes both temporally and spatially we collected mineral precipitates from selected sites in Hungary (Bükfürdo, Szechenyi, Szentes, Igal, Hajduszoboszlo). The samples of up to 8 cm thickness were recovered from different positions of the geothermal systems and precipitated from waters of various temperatures (40-120 °C) and variable overall chemical composition. Most of these scalings show fine lamination patterns representing mineral deposition from weeks up to 45 years at our study sites. Solid-fluid interaction over time captured in the samples are investigated applying high-resolution analytical techniques such as laser-ablation mass-spectrometry and electron microprobe, micromill-sampling for stable isotope analysis, and micro-XRD combined with hydrogeochemical modeling. A detailed investigation of the processes determining the formation and growth of precipitates can help to elucidate the short-term versus long-term geothermal performance with regard to anthropogenic and natural reservoir and production dynamics. Changes in fluid chemistry, temperature, pressure, pH, degassing rate (CO2) and flow rate are reflected by the mineralogical, chemical and isotopic composition of the precipitates. Consequently, this high-resolution approach is intended as a contribution to decipher the

  6. Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Gibson, J.D.; Swan, F.H.; Wesling, J.R.; Bullard, T.F.; Perman, R.C.; Angell, M.M.; DiSilvestro, L.A.

    1992-01-01

    Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques.

  7. Fluid-rock interactions in the Rhine Graben: A thermodynamic model of the hydrothermal alteration observed in deep drilling

    NASA Astrophysics Data System (ADS)

    Komninou, A.; Yardley, B. W. D.

    1997-02-01

    Deep drilling at Soultz-sous-Forêts, France, on the western flanks of the Rhine Graben, has penetrated Hercynian granite underlying Mesozoic sediments. Veins are present throughout the drilled granite, and there are flows of warm water localized in fractures within the granite. Detailed mineralogical study of core material from the research drillhole EPS 1 has been carried out in order to assess the alteration history of the Soultz granite, part of the crystalline basement of the Rhine Graben. The results of the study have been used, in conjunction with analyses of present-day fluids from deep drilling in the Rhine Graben reported in the literature, to model thermodynamically the alteration process, and in particular to evaluate if it is likely to be continuing today. Reaction-path calculations show that if deep basinal brines, such as are known from sediments of the central Rhine Graben, react with Hercynian granite, they will form different alteration assemblages depending on both the path that the fluid follows (e.g., descending through sediments or through granite) and the extent of preexisting alteration of the granite. The calculations suggest that fluid now sampled from granite in EPS-1 achieved its peak temperature, c. 200°C, while within Permo-Triassic sandstone. The modeling also indicates that present-day fluids from the Rhine Graben system are capable of producing the vein quartz and possibly also the baryte veins, seen in the EPS 1 core. Much of the alteration present in the granite in the vicinity of veins and fractures may have been produced by a flow regime similar to that prevailing today.

  8. Corrective Tibial Osteotomy in Young Adults Using an Intramedullary Nail

    PubMed Central

    Kim, Kang-Il; Thaller, Peter H.; Ramteke, Alankar; Lee, Seung-Hyuk

    2014-01-01

    Purpose The purpose of this study was to document results of a less invasive technique of open wedge proximal tibial osteotomy (PTO) for the varus knee in young adults using an intramedullary tibial nail. Materials and Methods We prospectively studied 24 knees in 16 young patients with varus knee deformity. The mean follow-up was 54 months (range, 36 to 107 months) and the mean age of patients at the time of operation was 25.8 years (range, 18 to 40 years). The open wedge PTO was performed below tibial tuberosity using a percutaneous multiple drill-hole technique. Conventional intramedullary tibial nail was used for fixation without bone graft. Radiographic evaluations were made using mechanical alignment (MA), posterior tibial slope angle, and Insall-Salvati ratio. Union time, loss of correction, implant failure, and associated complications were also investigated. Results The mean MA was significantly changed from -9.7° preoperatively to 1.1° at the final follow-up (p<0.001). There was no significant change in the proximal tibial anatomy and patellar height. All patients achieved radiographic bony union at an average of 3.1 months without loss of correction. The only complication was knee pain due to nail prominence in 3 patients. Conclusions Radiographic evaluation indicated that PTO using an intramedullary tibial nail leads to significant improvement in radiographic parameters without changes in posterior tibial slope or patellar height. We found that this technique could be a less invasive and effective alternative for correction of the varus knee in young adults. PMID:24944974

  9. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multi-frequency EM

    NASA Astrophysics Data System (ADS)

    Hendricks, S.; Hoppmann, M.; Hunkeler, P. A.; Kalscheuer, T.; Gerdes, R.

    2015-12-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise and accumulate beneath nearby sea ice to form a several meter thick sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator for ice - ocean interactions. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and sub-ice platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions from platelet-layer conductivities using Archie's Law. The thickness results agreed well with drill-hole validation datasets within the uncertainty range, and the ice-volume fraction also yielded plausible results. Our findings imply that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties. However, we emphasize that the successful application of this technique requires a break with traditional EM sensor calibration strategies due to the need of absolute calibration with respect to a physical forward model.

  10. Mineralogical, geochemical and isotopic features of tuffs from the CFDDP drill hole: Hydrothermal activity in the eastern side of the Campi Flegrei volcano (southern Italy)

    NASA Astrophysics Data System (ADS)

    Mormone, A.; Troise, C.; Piochi, M.; Balassone, G.; Joachimski, M.; De Natale, G.

    2015-01-01

    A 506 m drill-hole has been recently drilled in the framework of the Campi Flegrei Deep Drilling Project (CFDDP) and the International Continental Scientific Drilling Program (ICDP) with the intention of coring the subsurface in the eastern sector of the Campi Flegrei caldera. The borehole, located in the western district of the Neapolitan city (Bagnoli Plain) 3 km to the east of the most active volcanic area and about 5 m above sea level, is now targeted for monitoring purposes. This paper reports the results obtained from the analysis of two short cores collected at depths of - 443 and - 506 m below the ground level. The cores sampled two pre-caldera tuffs. Observations performed by optical and scanning electron microscopy, energy dispersive spectroscopy and powder X-ray diffraction were used to achieve data on the primary lithology, both primary and secondary mineralogical assemblages, and the relationship between texture and secondary mineralization. Sr isotope ratios were determined on selected primary feldspars, whereas δ13C and δ18O analyses were performed on carbonates from veins and filled-voids in tuffs. Our results provide information on the hydrothermal system in the eastern sector of the caldera that was not among the goals in the previous drilling programs. Secondary mineralization suggests a saline hydrothermal environment characterized by fluids that progressively evolved from boiling toward more alkaline and cooler conditions. A paleo-temperature of ca. 160 °C has been inferred from authigenic mineral occurrences and calculated on the basis of equilibria between cored calcites and fluids presently emitted at the surface, by using carbon and oxygen isotope data. The temperature measured at the bottom of the drilling is about 80 °C.

  11. Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - II. Microstructures and their implications for permeability and strength

    USGS Publications Warehouse

    Moore, Diane E.; Lockner, D.A.; Ito, H.; Ikeda, R.; Tanaka, H.; Omura, K.

    2009-01-01

    Samples of damage-zone granodiorite and fault core from two drillholes into the active, strike-slip Nojima fault zone display microstructures and alteration features that explain their measured present-day strengths and permeabilities and provide insight on the evolution of these properties in the fault zone. The least deformed damage-zone rocks contain two sets of nearly perpendicular (60-90?? angles), roughly vertical fractures that are concentrated in quartz-rich areas, with one set typically dominating over the other. With increasing intensity of deformation, which corresponds generally to increasing proximity to the core, zones of heavily fragmented rock, termed microbreccia zones, develop between prominent fractures of both sets. Granodiorite adjoining intersecting microbreccia zones in the active fault strands has been repeatedly fractured and locally brecciated, accompanied by the generation of millimeter-scale voids that are partly filled with secondary minerals. Minor shear bands overprint some of the heavily deformed areas, and small-scale shear zones form from the pairing of closely spaced shear bands. Strength and permeability measurements were made on core collected from the fault within a year after a major (Kobe) earthquake. Measured strengths of the samples decrease regularly with increasing fracturing and fragmentation, such that the gouge of the fault core and completely brecciated samples from the damage zone are the weakest. Permeability increases with increasing disruption, generally reaching a peak in heavily fractured but still more or less cohesive rock at the scale of the laboratory samples. Complete loss of cohesion, as in the gouge or the interiors of large microbreccia zones, is accompanied by a reduction of permeability by 1-2 orders of magnitude below the peak values. The core samples show abundant evidence of hydrothermal alteration and mineral precipitation. Permeability is thus expected to decrease and strength to increase somewhat

  12. Occurrence and significance of microbialites in the uplifted Tasmaloum reef (SW Espiritu Santo, SW Pacific)

    NASA Astrophysics Data System (ADS)

    Cabioch, Guy; Taylor, Frederick W.; Corrège, Thierry; Récy, Jacques; Edwards, Lawrence R.; Burr, George S.; Le Cornec, Florence; Banks, Kirsten A.

    1999-07-01

    In the SW Pacific Ocean, subduction of the d'Entrecasteaux ridge system has caused rapid uplift of the central New Hebrides Island Arc. The maximum uplift rate of 6 mm yr -1 occurs along the southwest coast of Espiritu Santo Island, near Tasmaloum. The Tasmaloum uplifted reef sequence internal structure, which is strongly linked to its tectonic context, was investigated through a series of drill-holes to depths up to 42 m. Although a stable tropical coast would undergo approximately 120 m of post-glacial sea-level rise, the net relative sea-level rise on such a rapidly uplifting coast is only about 20 m. Colonization of the Tasmaloum fringing reef occurred by 24 ka, upon a pre-reef substrate composed of a thick bioclastic sand formation accumulated during the last glacial period. During the post-glacial sea-level rise, the vertical succession of reef assemblages reflects environmental and bathymetric variations controlled by the interplay of rapid, but variable rates of sea-level rise and more or less constant uplift of 5-6 mm yr -1. Microbialite crusts, composed of high-magnesian calcite laminae, occur in the Tasmaloum reef from 20 to 6 ka and are particularly abundant from 16 to 10 ka. The development of microbialite crusts is related to nutrient enrichment of interstitial waters through mixing with meteoric groundwater. After 6 ka, when sea level ceased rising in the region and continuing uplift caused rapid emergence of the reef, microbialites disappear within the subtidal assemblages. Several explanations can be put forward for their disappearance. In particular, nutrient input changes are a likely cause. A new hydrologic and oceanographic regime was established when sea level ceased rising. This change was accompanied by warming of tropical waters.

  13. Reservoir uncertainty, Precambrian topography, and carbon sequestration in the Mt. Simon Sandstone, Illinois Basin

    USGS Publications Warehouse

    Leetaru, H.E.; McBride, J.H.

    2009-01-01

    Sequestration sites are evaluated by studying the local geological structure and confirming the presence of both a reservoir facies and an impermeable seal not breached by significant faulting. The Cambrian Mt. Simon Sandstone is a blanket sandstone that underlies large parts of Midwest United States and is this region's most significant carbon sequestration reservoir. An assessment of the geological structure of any Mt. Simon sequestration site must also include knowledge of the paleotopography prior to deposition. Understanding Precambrian paleotopography is critical in estimating reservoir thickness and quality. Regional outcrop and borehole mapping of the Mt. Simon in conjunction with mapping seismic reflection data can facilitate the prediction of basement highs. Any potential site must, at the minimum, have seismic reflection data, calibrated with drill-hole information, to evaluate the presence of Precambrian topography and alleviate some of the uncertainty surrounding the thickness or possible absence of the Mt. Simon at a particular sequestration site. The Mt. Simon is thought to commonly overlie Precambrian basement granitic or rhyolitic rocks. In places, at least about 549 m (1800 ft) of topographic relief on the top of the basement surface prior to Mt. Simon deposition was observed. The Mt. Simon reservoir sandstone is thin or not present where basement is topographically high, whereas the low areas can have thick Mt. Simon. The paleotopography on the basement and its correlation to Mt. Simon thickness have been observed at both outcrops and in the subsurface from the states of Illinois, Ohio, Wisconsin, and Missouri. ?? 2009. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  14. A molecular and isotopic study of palaeoenvironmental conditions through the middle Cambrian in the Georgina Basin, central Australia

    NASA Astrophysics Data System (ADS)

    Pagès, Anais; Schmid, Susanne; Edwards, Dianne; Barnes, Stephen; He, Nannan; Grice, Kliti

    2016-08-01

    The Cambrian period marks an important point in Earth's history with profound changes in the ocean's biogeochemistry and the occurrence of the most significant evolutionary event in the history of life, the Cambrian explosion. The Cambrian explosion is described as a succession of complex cycles of extinctions and radiations. This study integrates biomarkers and their compound-specific stable carbon isotopes to investigate the palaeoenvironmental depositional conditions in middle Cambrian (Series 3) sedimentary rocks (Thorntonia Limestone, Inca Formation and Currant Bush Limestone) from two drillholes in the Undilla Sub-basin in the eastern Georgina Basin, central Australia. The occurrence of photic zone euxinia (PZE) was detected throughout these three formations by the identification of green sulfur bacteria Chlorobiaceae-derived biomarkers, including a series of 2,3,6-aryl isoprenoids and the intact biomarker isorenieratane. Pulses of enhanced PZE conditions were detected in two core intervals (90-110 mKB, Currant Bush Limestone and 170-200 mKB, Inca Formation) by an increase in the 2,3,6-aryl isoprenoids and C19 biphenyl concentrations. These enhanced PZE conditions were followed by blooms of phytoplankton, as demonstrated by the increase in algal-derived biomarker (i.e. pristane, phytane and the C19n-alkane) concentrations and compound-specific isotopes. These observations confirm that palaeoenvironmental conditions were similar to those reported for the Permian/Triassic and Triassic/Jurassic mass extinction events. The sterane distributions varied across the three formations reflecting possible changes in the phytoplanktonic communities through time. Although a rise in atmospheric oxygen during the Cambrian has been previously associated with the rapid evolution of metazoans, the ecological challenges related to widespread anoxia must have had a major influence on the evolution of life in Cambrian oceans.

  15. A multiple-point geostatistical method for characterizing uncertainty of subsurface alluvial units and its effects on flow and transport

    USGS Publications Warehouse

    Cronkite-Ratcliff, C.; Phelps, G.A.; Boucher, A.

    2012-01-01

    This report provides a proof-of-concept to demonstrate the potential application of multiple-point geostatistics for characterizing geologic heterogeneity and its effect on flow and transport simulation. The study presented in this report is the result of collaboration between the U.S. Geological Survey (USGS) and Stanford University. This collaboration focused on improving the characterization of alluvial deposits by incorporating prior knowledge of geologic structure and estimating the uncertainty of the modeled geologic units. In this study, geologic heterogeneity of alluvial units is characterized as a set of stochastic realizations, and uncertainty is indicated by variability in the results of flow and transport simulations for this set of realizations. This approach is tested on a hypothetical geologic scenario developed using data from the alluvial deposits in Yucca Flat, Nevada. Yucca Flat was chosen as a data source for this test case because it includes both complex geologic and hydrologic characteristics and also contains a substantial amount of both surface and subsurface geologic data. Multiple-point geostatistics is used to model geologic heterogeneity in the subsurface. A three-dimensional (3D) model of spatial variability is developed by integrating alluvial units mapped at the surface with vertical drill-hole data. The SNESIM (Single Normal Equation Simulation) algorithm is used to represent geologic heterogeneity stochastically by generating 20 realizations, each of which represents an equally probable geologic scenario. A 3D numerical model is used to simulate groundwater flow and contaminant transport for each realization, producing a distribution of flow and transport responses to the geologic heterogeneity. From this distribution of flow and transport responses, the frequency of exceeding a given contaminant concentration threshold can be used as an indicator of uncertainty about the location of the contaminant plume boundary.

  16. Fluid-rock interactions in the Rhine Graben: A thermodynamic model of the hydrothermal alteration observed in deep drilling

    SciTech Connect

    Komninou, A.; Yardley, B.W.D.

    1997-02-01

    Deep drilling at Soultz-sous-Forets, France, on the western flanks of the Rhine Graben, has penetrated Hercynian granite underlying Mesozoic sediments. Veins are present throughout the drilled granite, and there are flows of warm water localized in fractures within the granite. Detailed mineralogical study of core material from the research drillhole EPSI has been carried out in order to assess the alteration history of the Soultz granite, part of the crystalline basement of the Rhine Graben. The results of the study have been used, in conjunction with analyses of present-day fluids from deep drilling in the Rhine Graben reported in the literature, to model thermodynamically the alteration process, and in particular to evaluate if it is likely to be continuing today. Reaction-path calculations show that if deep basinal brines, such as are known from sediments of the central Rhine Graben, react with Hercynian granite, they will form different alteration assemblages depending on both the path that the fluid follows (e.g., descending through sediments or through granite) and the extent of preexisting alteration of the granite. The calculations suggest that fluid now sampled from granite in EPS-1 achieved its peak temperature, c. 200{degrees}C while within Permo-Triassic sandstone. The modeling also indicates that present-day fluids from the Rhine Graben system are capable of producing the vein quartz and possibly also the baryte veins, seen in the EPSI core. Much of the alteration present in the granite in the vicinity of veins and fractures may have been produced by a flow regime similar to that prevailing today. 48 refs., 15 figs., 4 tabs.

  17. Integrated geophysical imaging of a concealed mineral deposit: a case study of the world-class Pebble porphyry deposit in southwestern Alaska

    USGS Publications Warehouse

    Shah, Anjana K.; Bedrosian, Paul A.; Anderson, Eric D.; Kelley, Karen D.; Lang, James

    2013-01-01

    We combined aeromagnetic, induced polarization, magnetotelluric, and gravity surveys as well as drillhole geologic, alteration, magnetic susceptibility, and density data for exploration and characterization of the Cu-Au-Mo Pebble porphyry deposit. This undeveloped deposit is almost completely concealed by postmineralization sedimentary and volcanic rocks, presenting an exploration challenge. Individual geophysical methods primarily assist regional characterization. Positive chargeability and conductivity anomalies are observed over a broad region surrounding the deposit, likely representing sulfide minerals that accumulated during multiple stages of hydrothermal alteration. The mineralized area occupies only a small part of the chargeability anomaly because sulfide precipitation was not unique to the deposit, and mafic rocks also exhibit strong chargeability. Conductivity anomalies similarly reflect widespread sulfides as well as water-saturated glacial sediments. Mineralogical and magnetic susceptibility data indicate magnetite destruction primarily within the Cu-Au-Mo mineralized area. The magnetic field does not show a corresponding anomaly low but the analytic signal does in areas where the deposit is not covered by postmineralization igneous rocks. The analytic signal shows similar lows over sedimentary rocks outside of the mineralized area, however, and cannot uniquely distinguish the deposit. We find that the intersection of positive chargeability anomalies with analytic signal lows, indicating elevated sulfide concentrations but low magnetite at shallow depths, roughly delineates the deposit where it is covered only by glacial sediments. Neither chargeability highs nor analytic signal lows are present where the deposit is covered by several hundred meters of sedimentary and volcanic rocks, but a 3D resistivity model derived from magnetotelluric data shows a corresponding zone of higher conductivity. Gravity data highlight geologic features within the

  18. Shallow subsurface geology of part of the Savannah River alluvial valley in the upper Coastal Plain of Georgia and South Carolina

    USGS Publications Warehouse

    Leeth, D.C.; Nagle, D.D.

    1996-01-01

    The depth to which Coastal Plain rivers incise underlying formations is an important control on local and regional hydrologic flow systems. In order to clarify these stream/aquifer relations, a better understanding of the shallow subsurface geology of the Savannah River was necessary. To accomplish this, three drillhole transects were completed across a part of the Savannah River alluvial valley in September 1993, and five geologic sections were constructed from the data. The alluvium is coarser, more angular, and more poorly sorted than the underlying formations, and lithologic differences between the strata are readily apparent, especially in areas where the underlying strata are of marine origin. Inspection of the transects indicates an asymmetry to both the alluvial terrace complex and the underlying bedrock strath. The alluvium thins in a coastward direction; and similarly, bulk-grain size diminishes in a downstream direction. This phenomenon has remained constant over time and is most likely a function of the change in slope which occurs when the river traverses the Fall Line north of the study area. The maximum thickness of the alluvial valley fill is 50 ft. The elevation of the unconformity between the alluvium and the underlying formation is far below the lowest elevation of the modern-day thalweg, indicating that the alluvial system has aggraded to form the modern-day Savannah River Valley. Formerly, the Savannah River was located immediately adjacent to and east of the modern floodplain when the river valley was formed by a cyclic pattern of infilling and subsequent entrenchment that gave rise to an irregular bedrock surface beneath the depositional terrace system. After this depositional period, the river migrated to the southwest and began a period of downcutting that ended with the formation of the unconformity (erosional terrace) that lies some 45 ft. beneath the modern-day river. The protracted southwestward migration of the river system is perhaps

  19. Gulf coastal Pleistocene units and time stratigraphy; reevaluation and problems of Atlantic correlation

    SciTech Connect

    Otvos, E.G. . Geology Section)

    1993-03-01

    Outdated glacial subdivisions and misinterpretations of alluvial interfluve ridges as marine terraces hampered advances in coastal stratigraphy. One problem involves C.W. Cooke's extension of his Atlantic shorelines along the NE Gulf into the Mississippi Embayment. The mirage of an inter-Wisconsinan interglacial gave way to beliefs in high glacial Wisconsinan sea levels that were assumed to have resulted in barriers and intensive alluvial aggradation on the TX-LA coastal plain. Without vertical definitions, Fisk assigned formation status to alluvial and brackish-marine sediments that directly underlie four coastwise Pleistocene terraces in SW Louisiana. The youngest (Prairie) and associated formations were recently (re)defined and correlated with other coastal areas. Brackish and marine deposits in the subsurface have been correlated with Fisk's second youngest coastwise surface. Detailed facies analyses of cores from hundreds of drillholes indicated that, in sharp contrast with Plio-Pleistocene barriers on the Atlantic coast, only a single, Sangamonian (Sg) barrier shore complex remains on the NE Gulf coastal plain after intensive uplift/erosion. Few isolated remnants of pre-Sg Pleistocene alluvial units occur, including flora elements in peat lenses at one location. An early, low Sg sea level stand near Apalachicola is marked by transgressive deposits at c. [minus]37.5m. Thin NE Gulf Sg sequence includes the fine-grained, open marine-to-estuarine Biloxi, the regressive, shallow subtidal-to-supratidal, mainland Gulfport barrier and the alluvial Prairie Formations. These are correlatable Gulfwide. Contrary to widespread assumption, the Gulfport-Ingleside barriers were not islands but mainland strandplains. The Sg complex correlates with oxygen isotope Stage 5 units of the Mid/South Atlantic coastal plain and shelf. Thick LA-TX shelf/slope intervals display about ten fourth-order cycles within 4 primary ones.

  20. Prunetin signals via G-protein-coupled receptor, GPR30(GPER1): Stimulation of adenylyl cyclase and cAMP-mediated activation of MAPK signaling induces Runx2 expression in osteoblasts to promote bone regeneration.

    PubMed

    Khan, Kainat; Pal, Subhashis; Yadav, Manisha; Maurya, Rakesh; Trivedi, Arun Kumar; Sanyal, Sabyasachi; Chattopadhyay, Naibedya

    2015-12-01

    Prunetin is found in red clover and fruit of Prunus avium (red cherry). The effect of prunetin on osteoblast function, its mode of action and bone regeneration in vivo were investigated. Cultures of primary osteoblasts, osteoblastic cell line and HEK293T cells were used for various in vitro studies. Adult female rats received drill-hole injury at the femur diaphysis to assess the bone regenerative effect of prunetin. Prunetin at 10nM significantly (a) increased proliferation and differentiation of primary cultures of osteoblasts harvested from rats and (b) promoted formation of mineralized nodules by bone marrow stromal/osteoprogenitor cells. At this concentration, prunetin did not activate any of the two nuclear estrogen receptors (α and β). However, prunetin triggered signaling via a G-protein-coupled receptor, GPR30/GPER1, and enhanced cAMP levels in osteoblasts. G15, a selective GPR30 antagonist, abolished prunetin-induced increases in osteoblast proliferation, differentiation and intracellular cAMP. In osteoblasts, prunetin up-regulated runt-related transcription factor 2 (Runx2) protein through cAMP-dependent Erk/MAP kinase activation that ultimately resulted in the up-regulation of GPR30. Administration of prunetin at 0.25mg/kg given to rats stimulated bone regeneration at the site of drill hole and up-regulated Runx2 expression in the fractured callus and the effect was comparable to human parathyroid hormone, the only clinically used osteogenic therapy. We conclude that prunetin promotes osteoinduction in vivo and the mechanism is defined by signaling through GPR30 resulting in the up-regulation of the key osteogenic gene Runx2 that in turn up-regulates GPR30. PMID:26345541

  1. Melt-rock interactions and fabric development of peridotites from North Pond in the Kane area, Mid-Atlantic Ridge: Implications of microstructural and petrological analyses of peridotite samples from IODP Hole U1382A

    NASA Astrophysics Data System (ADS)

    Harigane, Yumiko; Abe, Natsue; Michibayashi, Katsuyoshi; Kimura, Jun-Ichi; Chang, Qing

    2016-06-01

    North Pond is an isolated sedimentary pond on the western flank of the Kane area along the Mid-Atlantic Ridge. Drill-hole U1382A of IODP Expedition 336 recovered peridotite and gabbro samples from a sedimentary breccia layer in the pond, from which we collected six fresh peridotite samples. The peridotite samples came from the southern slope of the North Pond where an oceanic core complex is currently exposed. The samples were classified as spinel harzburgite, plagioclase-bearing harzburgite, and a vein-bearing peridotite that contains tiny gabbroic veins. No obvious macroscopic shear deformation related to the formation of a detachment fault was observed. The spinel harzburgite with a protogranular texture was classified as refractory peridotite. The degree of partial melting of the spinel harzburgite is estimated to be ˜17%, and melt depletion would have occurred at high temperatures in the uppermost mantle beneath the spreading axis. The progressive melt-rock interactions between the depleted spinel harzburgite and the percolating melts of Normal-Mid Ocean Ridge Basalt (N-MORB) produced the plagioclase-bearing harzburgite and the vein-bearing peridotite at relatively low temperatures. This implies that the subsequent refertilization occurred in an extinct spreading segment of the North Pond after spreading at the axis. Olivine fabrics in the spinel and plagioclase-bearing harzburgites are of types AG, A, and D, suggesting the remnants of a mantle flow regime beneath the spreading axis. The initial olivine fabrics appear to have been preserved despite the later melt-rock interactions. The peridotite samples noted above preserve evidence of mantle flow and melt-rock interactions beneath a spreading ridge that formed at ˜8 Ma.

  2. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Quarterly progress report, July 1--September 30, 1995

    SciTech Connect

    Allison, M.L.

    1995-10-30

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. Technical progress this quarter is divided into regional stratigraphy, case studies, stochastic modeling and fluid-flow simulation, and technology transfer activities. The regional stratigraphy of the Ferron Sandstone outcrop belt is being described and interpreted. Detailed geological and petrophysical characterization of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir, is continuing at selected case-study areas. Interpretations of lithofacies, bounding surfaces, and other geologic information are being combined with permeability measurements from closely spaced traverses and from drill-hole cores (existing and two drilled during the quarter). Petrophysical and statistical analyses are being incorporated with the geological characterization to develop a three-dimensional model of the reservoirs through fluid-flow simulation.

  3. Geological and petrophysical characterization of the Ferron sandstone for 3-D simulation of a fluvial-deltaic reservoir. [Quarterly progress report], October 1--December 31, 1995

    SciTech Connect

    Allison, M.L.

    1995-12-31

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Technical progress this quarter is divided into regional stratigraphy, case studies, and technology transfer activities. The Kf-2 contains more and cleaner sand, indicating a more wave-modified environment of deposition. The regional stratigraphy of the Ferron Sandstone outcrop belt from Last Chance Creek to Ferron Creek was described and interpreted. Photomosaics and a database of existing surface and subsurface data are being used to determine the extent and depositional environment of each parasequence, and the nature of the contacts with adjacent rocks or flow units. Detailed geological and petrophysical characterization of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir, is continuing at selected case-study areas. Interpretations of lithofacies, bounding surfaces, and other geologic information are being combined with permeability measurements from closely spaced traverses and from drill-hole cores (described this quarter).

  4. How fault zones impact regional permeability and groundwater systems: insights from global database of fault zone studies.

    NASA Astrophysics Data System (ADS)

    Scibek, J.; McKenzie, J. M.; Gleeson, T.

    2014-12-01

    Regional and continental scale groundwater flow models derive aquifer permeability distributions from datasets based on hydraulic tests and calibrated local and regional flow models, however, much of this data does not account for barrier/conduit effects of fault zones, local and regional geothermal flow cells, and other fault-controlled flow systems. In this study we researched and compiled fault zone permeability and conceptual permeability models in different geologic settings from published multidisciplinary literature (structural- and hydro-geology, engineering geology of tunnels and mines, and geothermal projects among others). The geospatial database focuses on data-rich regions such as North America, Europe, and Japan. Regionalization of the dominant conceptual models of fault zones was regionalized based on geological attributes and tested conceptually with simple numerical models, to help incorporate the effect of fault zones on regional to continental flow models. Results show that for large regional and continental scale flow modeling, the fault zone data can be generalized by geology to determine the relative importance of fault conduits vs fault barriers, which can be converted to effective anisotropy ratios for large scale flow, although local fault-controlled flow cells in rift zones require appropriate upscaling. The barrier/conduit properties of fault zones are present in all regions and rock types, and the barrier effect must be properly conceptualized in large scale flow models. The fault zone data from different geologic disciplines have different biases (e.g. outcrop studies, deep drillhole tests, tunnels, etc.) depending on scale of hydraulic tests. Finally, the calibrated recharge estimates for fault controlled flow systems may be lower than for unfaulted flow systems due to predominant barrier (regional anisotropy or permeability reduction), suggesting a "scaling effect" on recharge estimates.

  5. A study on the discrete image method for calculation of transient electromagnetic fields in geological media

    NASA Astrophysics Data System (ADS)

    Meng, Qing-Xin; Pan, He-Ping; Luo, Miao

    2015-12-01

    We conducted a study on the numerical calculation and response analysis of a transient electromagnetic field generated by a ground source in geological media. One solution method, the traditional discrete image method, involves complex operation, and its digital filtering algorithm requires a large number of calculations. To solve these problems, we proposed an improved discrete image method, where the following are realized: the real number of the electromagnetic field solution based on the Gaver-Stehfest algorithm for approximate inversion, the exponential approximation of the objective kernel function using the Prony method, the transient electromagnetic field according to discrete image theory, and closed-form solution of the approximate coefficients. To verify the method, we tentatively calculated the transient electromagnetic field in a homogeneous model and compared it with the results obtained from the Hankel transform digital filtering method. The results show that the method has considerable accuracy and good applicability. We then used this method to calculate the transient electromagnetic field generated by a ground magnetic dipole source in a typical geoelectric model and analyzed the horizontal component response of the induced magnetic field obtained from the "ground excitation-stratum measurement" method. We reached the conclusion that the horizontal component response of a transient field is related to the geoelectric structure, observation time, spatial location, and others. The horizontal component response of the induced magnetic field reflects the eddy current field distribution and its vertical gradient variation. During the detection of abnormal objects, positions with a zero or comparatively large offset were selected for the drillhole measurements or a comparatively long observation delay was adopted to reduce the influence of the ambient field on the survey results. The discrete image method and forward calculation results in this paper

  6. The 2.7 Ga Pilbara Drilling Project, Western Australia: Paleomagnetic Results

    NASA Astrophysics Data System (ADS)

    Poitou, C.; Besse, J.; Valet, J.; Philippot, P.

    2007-12-01

    The Pilbara Drilling Project diamond drillhole intersects subaerial basaltic flows (Maddina Formation, 2715 Ma), stromatolitic carbonates, interbedded black shale (Meentheena Member, Tumbiana Formation) and underlying volcaniclastic sandstones (2719 Ma). Three to four 15 mm diameter and 13 mm long tiny cylindrical specimens were sampled every metre downcore and subjected to thermal and alternating field demagnetization. The demagnetization results of the upper Maddina basalts (0-40 m depth) revealed one or two distinct magnetization components. The high temperature component was observed for more than 50% of the samples and could not be isolated before 550°C. It shows normal polarity and is always almost antiparallel to the low temperature component of reverse polarity. Alternating field demagnetization displayed similar characteristics with opposite directions for the low reverse and high normal coercivity components. We thus consider that the high unblocking temperature and high coercivity grains carry the same normal characteristic component. In contrast to the basaltic flows, the Tuffaceous materials (98-104m depth) show a unique component of reverse polarity which could either reflect thermo-chemico-viscous overprint or an actual reverse polarity before emplacement of the basaltic flows. Paleomagnetic studies on interbedded sedimentary materials and complementary rock magnetic experiments are under way to discriminate between the two hypotheses. If the second scenario had to be retained we would have identified the second oldest known reversal of the Earth's magnetic field (first one was presented in Strik et al., doi:10.1029\\slash2003JB002475, 2003). Other implications of the present study would concern the characteristics of the paleosecular variation during Precambrian time but also lateral drift of continental plates. This would also constrain the apparent polar wander path of the Pilbara Craton and the origin of plate velocity which is suggested to be

  7. Structure of the Rambler Rhyolite, Baie Verte Peninsula, Newfoundland: Inversions using UBC-GIF Grav3D and Mag3D

    NASA Astrophysics Data System (ADS)

    Spicer, B.; Morris, B.; Ugalde, H.

    2011-09-01

    Hosted within the Pacquet Harbour Group (PHG) on the Baie Verte Peninsula of north-central Newfoundland, the Rambler rhyolite is a 487 Ma unit of felsic tuffs, flows and subvolcanic intrusive rocks. The PHG has been affected by multiple phases of deformation with the youngest D4 deformation event producing broad northeast plunging upright cross folds in the Rambler rhyolite. Fold culminations on the upper bounding surface of the rhyolite host Cu +/- Au volcanogenic massive sulfide deposits (e.g. Rambler and Ming mines). Geophysical inversions of recently acquired high resolution gravity and magnetic data have been implemented to determine the extent of the fold axis (dome) at depth. To direct the outcome of the inversion process towards a more geologically reasonable solution this study outlines a procedure which permits the inclusion of known geological and geophysical constraints into the input (reference) model for inversion using the MAG3D and GRAV3D algorithms provided by the University of British Columbia Geophysical Inversion Facility. Reference model constraints included surficial geological contacts as defined by aeromagnetic data, and subsurface distribution of physical property variations from a series of drill-hole logs. The output (computed) model images the surface of the rhyolite dome as dipping roughly 40° to the northeast as a series of voxels with density values ranging from 2.71 to 2.75 g/cm3. While previously published ore deposit models parallel this structure in the near surface, results from these inversions suggest deeper exploration may be favorable. Magnetic inversion modeling has not provided any insight into dome morphology however it outlines the distribution of gabbroic dykes surrounding the dome.

  8. Multifractal magnetic susceptibility distribution models of hydrothermally altered rocks in the Needle Creek Igneous Center of the Absaroka Mountains, Wyoming

    USGS Publications Warehouse

    Gettings, M.E.

    2005-01-01

    measured data. Comparisons of the model and data from drillholes show good but not perfect agreement. ?? 2005 Author(s). This work is licensed under a Creative Commons License.

  9. Buried Mesozoic rift basins of the U. S. middle Atlantic continental margin

    SciTech Connect

    Benson, R.N. )

    1991-08-01

    The Atlantic continental margin is one of the frontier areas for oil and gas exploration in the US. Most the activity has been offshore where Upper Jurassic-Lower Cretaceous siliciclastic and carbonate rocks have been the drilling objectives, with only one significant but noncommercial gas discover. Onshore, recent exploration activities have focused on early Mesozoic rift basins buried beneath the postrift sediments of the middle Atlantic coastal plain. Many of the basins are of interest because they contain fine-grained lacustrine rocks that have sufficient organic richness, if not lost through hydrocarbon generation, to be classified as source beds for oil or gas. Locations of inferred rift basins beneath the middle Atlantic coastal plain were determined by analysis of drill-hole data in combination with gravity anomaly and aeromagnetic maps. Two basins in Delaware and the Queen Anne basin of Maryland are imaged on a regional Vibroseis profile. Areas enclosing inferred rift basins in the offshore region were mapped from interpretation of seismic reflection profiles. Assuming that petroleum source beds are present in the basin (synrift) rocks, hydrocarbon-generation models (Lopatin method) indicate that for a basin just offshore Delaware that is buried by 7 km of postrift sediments, only dry gas would be present in reservoir rocks; for the Norfolk basin of the Virginia coast buried by only 3 km of postrift rocks, the upper few hundred meters of synrift rocks are still within the oil-generation window. The less deeply buried basins beneath the coastal plain likely are still within the oil window.

  10. Seismic analyses of the Triassic in Northern Germany for hydrogeothermal exploitation

    NASA Astrophysics Data System (ADS)

    Beilecke, Thies; Buness, Hermann; Musmann, Patrick; Schulz, Rüdiger

    2010-05-01

    Hydrothermal resources provide a large potential for the energy supply in Germany. However, the risk in reservoir detection is a major obstacle for its commercial utilization. Deep drillholes for a geothermal plant demand financial investments of several ten million Euros, without a comprehensive guarantee that the delivery and temperature of the required energy supply are met. A risk reduction is offered through the application of seismic techniques that have been developed in the oil and gas industry. Yet, in the geothermic business the topic of exploration cost reduction often has a higher priority. This is the reason why the necessity of 3D seismic is being repeatedly questioned. However, a seismic dataset from northern Germany currently being studied reveals a complicated fault zone network that has been partly generated by salt tectonics. It would be unrepresentable without the aid of 3D seismic. For fault detection in particular, time slices of the signal variance with a short time window and few traces have proven their suitability. In northern Germany some strata of the middle and lower Triassic are being regarded as hydrogeothermal reservoirs because of their temperature and permeability. Typically, areal amplitude distributions are being analyzed for anomalies. In the referred dataset, such areal analyses are however degraded by the intercalated complicated fault zone structures. In particular, in large sections of the lower Triassic the fault zone detection with signal variance calculation is also poor because of small seismic reflection amplitudes. It can be concluded that in some cases, 3D seismic offers the only way to recognize the subsurface structures. On the other hand, there are cases where even 3D seismic data needs carefully guided analysis instead of automatic algorithms.

  11. The Momotombo Geothermal Field, Nicaragua: Exploration and development case history study

    SciTech Connect

    1982-07-01

    This case history discusses the exploration methods used at the Momotombo Geothermal Field in western Nicaragua, and evaluates their contributions to the development of the geothermal field models. Subsequent reservoir engineering has not been synthesized or evaluated. A geothermal exploration program was started in Nicaragua in 1966 to discover and delineate potential geothermal reservoirs in western Nicaragua. Exploration began at the Momotombo field in 1970 using geological, geochemical, and geophysical methods. A regional study of thermal manifestations was undertaken and the area on the southern flank of Volcan Momotombo was chosen for more detailed investigation. Subsequent exploration by various consultants produced a number of geotechnical reports on the geology, geophysics, and geochemistry of the field as well as describing production well drilling. Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. This report presents the description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development. Our principal finding is that data developed at each stage were not sufficiently integrated to guide further work at the field, causing inefficient use of

  12. Dry Storage Casks Monitoring by Means of Ultrasonic Tomography

    NASA Astrophysics Data System (ADS)

    Salchak, Y.; Bulavinov, A.; Pinchuk, R.; Lider, A.; Bolotina, I.; Sednev, D.

    Spent nuclear fuel (SNF) is one of the most hazardous types of nuclear power plant waste. This fact emphasizes the importance of careful handling and storage of SNF. There are two current state-of-the art technologies of SNF storage facility: wet and dry. It is important to mention that IAEA does not determine which kind of handling strategy should be chosen, however it is noted that dry storage of SNF could be used for one hundred years. Mining and Chemical Enterprise (MCE) is one of the leading Russian companies that deals exclusively with the dry storage of SNF. This company has implemented a long-term storage scheme. At the same time MCE faced the challenge of nondestructive monitoring of the degradation process of structural material of cask and its sealing with weld seam. Currently, X-ray testing is used for this purpose but in order to provide an effective nonradioactive method of monitoring MCE has initiated a collaborative R&D project with TPU supported by the Russian Government. Ultrasonic industrial tomography technique was proposed as the solution. The method is based on application of phased and sparse arrays transducer with real-time visualization algorithm. Received acoustic data is processed and realized by means of Sampling Phased Array technology which is a collaborative development of TPU and I-Deal Technology, GmbH. The multichannel ultrasonic set-up of immersion control was assembled for performing testing of seven experimental specimens with representative defects (side drill-holes, notches, natural welding flaws). X-ray tomography of high-resolution was chosen as the reference method. All indications were successfully reconstructed in B and C-scans and 3D image. The next step is to automate the monitoring procedure completely and to introduce an evaluation tool for current flaw state and prediction of its further behavior.

  13. Geophysically inferred structural and lithologic map of the precambrian basement in the Joplin 1 degree by 2 degrees Quadrangle, Kansas and Missouri

    USGS Publications Warehouse

    McCafferty, Anne E.; Cordell, Lindrith E.

    1992-01-01

    This report is an analysis of regional gravity and aeromagnetic data that was carried out as part of a Conterminuous United States Mineral Assessment Program (CUSMAP) study of the Joplin 1° X 2° quadrangle, Kansas and Missouri. It is one in a series of reports representing a cooperative effort between the U.S. Geological Survey, Kansas Geological Survey, and Missouri Department of Natural Resources, Division of Geology and Land Survey. The work presented here is part of a larger project whose goal is to assess the mineral resource potential of the Paleozoic sedimentary section and crystalline basement within the quadrangle. Reports discussing geochemical, geological, and various other aspects of the study area are included in this Miscellaneous Field Studies Map series as MF-2125-A through MF-2125-E. Geophysical interpretation of Precambrian crystalline basement lithology and structure is the focus of this report. The study of the crystalline basement is complicated by the lack of exposures due to the presence of a thick sequence of Phanerozoic sedimentary cover. In areas where there are no outcrops, the geologist must turn to other indirect methods to assist in an understanding of the basement. Previous investigations of the buried basement in this region used available drill hole data, isotope age information, and regional geophysical data (Sims, 1990; Denison and others, 1984; Bickford and others, 1986). These studies were regional in scope and were presented at state and multistate scales. The work documented here used recently collected detailed gravity and aeromagnetic data to enhance the regional geologic knowledge of the area. Terrace-density and terrace-magnetization maps were calculated from the gravity and aeromagnetic data, leading directly to inferred physical-property (density and magnetization) maps. Once these maps were produced, the known geology and drill-hole data were reconciled with the physical-property maps to form a refined structural and

  14. Extensional geometries in the northern Grant Range, east-central Nevada - Implications for oil occurrences in Railroad Valley

    SciTech Connect

    Lund, K.; Perry, W.J. Jr. ); Beard, L.S. )

    1991-06-01

    Tertiary heterogeneous extension in the northern Grant Range, Nevada, is manifested by a stacked array of curviplanar low-angle attenuation faults that formed concurrent with arching. Attenuation was controlled by lithologic character, structural depth, and geometry of the arch. Extension appears to be greater on the west side of the range than on the east. On the east side of the range, the stacked array of low-angle attenuation faults is subparallel to bedding and attenuation is distributed across many stacked fault zones; except at highest crustal levels, these faults are blind. On the west side of the range, the low-angle attenuation faults of the stacked array merge into a single, major down-to-the-west fault zone across which as much as 19,000 ft of strata are omitted. Arching of the fault array resulted in an extensional culmination. Cross sections incorporating seismic and drill-hole data suggest that the low-angle attenuation faults (particularly the major down-to-the-west attenuation fault) seen in the range extend into Railroad Valley on the west side of the range with no significant offset by high-angle normal faults. Thus, the topographic expression of Grant Range and Railroad Valley may be due to the synchronous arching and low-angle faulting. These data indicate that both petroleum source and reservoir rocks in Railroad Valley oil fields are located in relatively immature but extensively fractured rocks of the upper plate to the extensional ramp. Lower plate rocks are metamorphosed, illustrate ductile behavior, and lack significant porosity and permeability.

  15. Regional seismic reflection profile from Railroad Valley to Lake Valley, east-central Nevada, reveals a variety of structural styles beneath Neogene basins

    SciTech Connect

    Potter, C.J.; Grow, J.A.; Lund, K.; Perry, W.J. Jr.; Miller, J.J.; Lee, M.W. )

    1991-06-01

    Two seismic reflection lines that compose a 90-km east-west profile at approximately 38{degree}25{prime}N latitude, east-central Nevada, help define the structure beneath Railroad Valley, White River Valley, the southern Egan Range, Cave Valley, Muleshoe Valley, the southern Schell Creek Range, and Lake Valley, Preliminary seismic interpretations are being integrated with ongoing geologic mapping, gravity, and magnetic studies and with drill-hole data along this transect. In the Grant Canyon oil field of Railroad Valley, a gently west-dipping normal fault appears to have controlled the development of the Neogene basin. The fault is clearly defined by fault-plane reflections and by terminations of east-dipping reflections from Tertiary and Paleozoic strata that have rotated toward the fault; the fault projects to nearby outcrops of a major low-angle extensional fault mapped in the Grant Range to the east. White River Valley at this latitude consists of three east-dipping half-grabens and two intervening basement highs. Two half-grabens in the western part of the valley are bounded by west-dipping faults with intermediate to steep dips. East-dipping reflections in the southern Egan Range correspond to a homoclinal Paleozoic panel overlain by a veneer of Late Cretaceous and early Tertiary rocks. The north end of Muleshoe Valley yields a narrow sag basin pattern between the southern Schell Creek Range and Dutch John Mountain, with no well-defined bounding faults. Lake Valley, on the east end of the profile, is a broad, complex basin containing normal faults with opposing dips. The progressive steepening of westerly dips in basin-fill beneath the west side of the basin suggests the presence of a major east-dipping listric fault.

  16. Relation between extensional geometry of the northern Grant Range and oil occurrences in railroad valley, East-Central Nevada

    SciTech Connect

    Lund, K.; Perry, W.J. Jr. ); Beard, L.S. )

    1993-06-01

    In the northern Grant Range, heterogeneous Neogene extension was dominated by synchronous arching and attenuation. Attenuation was accomplished along a stacked set of attenuation faults that formed at low angles to bedding as the Paleozoic carbonate and Paleogene rocks arched about a north-northwest axis. The style and amount of attenuation was controlled by lithologic character and structural depth of rock units and by geometry of the arch. On the steeper west side of the Grant Range arch, the curviplanar low-angle attenuation faults converge into a single shallowly west-dipping fault zone along which the stratigraphic juxtaposition of Mississippian units over Middle Cambrian units and Late Cretaceous granite marks the zone of maximum attenuation. Arching and heterogeneous extension resulted from uplift of the Grant Range relative to the structural basin of Railroad Valley to the west. This structural differentiation is a complex zone of subparallel-to-bedding, shallow-dipping attenuation faults rather than as a simple high-angle range-front fault. Seismic and drill-hole data indicate that low-angle attenuation faults in the range extend into Railroad Valley and control the structure buried in the valley. Mississippian and Paleocene to Eocene petroleum source rocks and Devonian to Oligocene reservoir rocks in Railroad Valley oil fields are in extensively fractured rocks of the upper plate to the major extensional fault system. Thus, relatively cold upper-plate rocks, immature with respect to hydrocarbon generation, were brought relatively down into contact with hotter lower-plate rocks by Neogene attenuation faulting. Oil in Railroad Valley, which is sourced from rocks as young as Eocene, was probably generated by this juxtaposition during Neogene crustal attenuation, and subsequently migrated into upper-plate fractured reservoirs. 101 refs., 10 figs.

  17. Increased Differentiation Capacity of Bone Marrow-Derived Mesenchymal Stem Cells in Aquaporin-5 Deficiency

    PubMed Central

    Yi, Fei; Khan, Muhammad; Gao, Hongwen; Hao, Feng; Sun, Meiyan; Zhong, Lili; Lu, Changzheng; Feng, Xuechao

    2012-01-01

    Mesenchymal stem cells (MSCs) are adult stem cells with a self-renewal and multipotent capability and express extensively in multitudinous tissues. We found that water channel aquaporin-5 (AQP5) is expressed in bone marrow-derived MSCs (BMMSCs) in the plasma membrane pattern. BMMSCs from AQP5−/− mice showed significantly lower plasma membrane water permeability than those from AQP5+/+ mice. In characterizing the cultured BMMSCs from AQP5−/− and AQP5+/+ mice, we found no obvious differences in morphology and proliferation between the 2 genotypes. However, the multiple differentiation capacity was significantly higher in AQP5−/− than AQP5+/+ BMMSCs as revealed by representative staining by Oil Red O (adipogenesis); Alizarin Red S and alkaline phosphatase (ALP; osteogenesis); and type II collagen and Safranin O (chondrogenesis) after directional induction. Relative mRNA expression levels of 3 lineage differentiation markers, including PPARγ2, C/EBPα, adipsin, collagen 1a, osteopontin, ALP, collagen 11a, collagen 2a, and aggrecan, were significantly higher in AQP5−/− -differentiating BMMSCs, supporting an increased differentiation capacity of AQP5−/− BMMSCs. Furthermore, a bone-healing process was accelerated in AQP5−/− mice in a drill-hole injury model. Mechanistic studies indicated a significantly lower apoptosis rate in AQP5−/− than AQP5+/+ BMMSCs. Apoptosis inhibitor Z-VAD-FMK increased the differentiation capacity to a greater extent in AQP5+/+ than AQP5−/− BMMSCs. We conclude that AQP5-mediated high plasma membrane water permeability enhances the apoptosis rate of differentiating BMMSCs, thus decreasing their differentiation capacity. These data implicate AQP5 as a novel determinant of differentiation of BMMSCs and therefore a new molecular target for regulating differentiation of BMMSCs during tissue repair and regeneration. PMID:22420587

  18. Geophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications

    SciTech Connect

    Grauch, V.J.S.; Sawyer, D.A.; Fridrich, C.J.; Hudson, M.R.

    2000-06-08

    Gravity and magnetic data, when integrated with other geophysical, geological, and rock-property data, provide a regional framework to view the subsurface geology in the southwestern Nevada volcanic field. The authors have loosely divided the region into six domains based on structural style and overall geophysical character. For each domain, they review the subsurface tectonic and magmatic features that have been inferred or interpreted from previous geophysical work. Where possible, they note abrupt changes in geophysical fields as evidence for potential structural or lithologic control on ground-water flow. They use inferred lithology to suggest associated hydrogeologic units in the subsurface. The resulting framework provides a basis for investigators to develop hypotheses for regional ground-water pathways where no drill-hole information exists. The authors discuss subsurface features in the northwestern part of the Nevada Test Site and west of the Nevada Test Site in more detail to address potential controls on regional ground-water flow away from areas of underground nuclear-weapons testing at Pahute Mesa. Subsurface features of hydrogeologic importance in these areas are (1) the resurgent intrusion below Timber Mountain, (2) a NNE-trending fault system coinciding with western margins of the Silent Canyon and Timber Mountain caldera complexes, (3) a north-striking, buried fault east of Oasis Mountain extending for 15 km, which they call the Hogback fault, and (4) an east-striking transverse fault or accommodation zone that, in part, bounds Oasis Valley basin on the south, which they call the Hot Springs fault. In addition, there is no geophysical nor geologic evidence for a substantial change in subsurface physical properties within a corridor extending from the northwestern corner of the Rainier Mesa caldera to Oasis Valley basin (east of Oasis Valley discharge area). This observation supports the hypothesis of other investigators that regional ground water

  19. Seasonal Changes of Arctic Sea Ice Physical Properties Observed During N-ICE2015: An Overview

    NASA Astrophysics Data System (ADS)

    Gerland, S.; Spreen, G.; Granskog, M. A.; Divine, D.; Ehn, J. K.; Eltoft, T.; Gallet, J. C.; Haapala, J. J.; Hudson, S. R.; Hughes, N. E.; Itkin, P.; King, J.; Krumpen, T.; Kustov, V. Y.; Liston, G. E.; Mundy, C. J.; Nicolaus, M.; Pavlov, A.; Polashenski, C.; Provost, C.; Richter-Menge, J.; Rösel, A.; Sennechael, N.; Shestov, A.; Taskjelle, T.; Wilkinson, J.; Steen, H.

    2015-12-01

    Arctic sea ice is changing, and for improving the understanding of the cryosphere, data is needed to describe the status and processes controlling current seasonal sea ice growth, change and decay. We present preliminary results from in-situ observations on sea ice in the Arctic Basin north of Svalbard from January to June 2015. Over that time, the Norwegian research vessel «Lance» was moored to in total four ice floes, drifting with the sea ice and allowing an international group of scientists to conduct detailed research. Each drift lasted until the ship reached the marginal ice zone and ice started to break up, before moving further north and starting the next drift. The ship stayed within the area approximately 80°-83° N and 5°-25° E. While the expedition covered measurements in the atmosphere, the snow and sea ice system, and in the ocean, as well as biological studies, in this presentation we focus on physics of snow and sea ice. Different ice types could be investigated: young ice in refrozen leads, first year ice, and old ice. Snow surveys included regular snow pits with standardized measurements of physical properties and sampling. Snow and ice thickness were measured at stake fields, along transects with electromagnetics, and in drillholes. For quantifying ice physical properties and texture, ice cores were obtained regularly and analyzed. Optical properties of snow and ice were measured both with fixed installed radiometers, and from mobile systems, a sledge and an ROV. For six weeks, the surface topography was scanned with a ground LIDAR system. Spatial scales of surveys ranged from spot measurements to regional surveys from helicopter (ice thickness, photography) during two months of the expedition, and by means of an array of autonomous buoys in the region. Other regional information was obtained from SAR satellite imagery and from satellite based radar altimetry. The analysis of the data collected has started, and first results will be

  20. Tensor controlled-source audiomagnetotelluric survey over the Sulphur Springs Thermal area, Valles Caldera, New Mexico, U.S.A.; Implication for structure of the western Caldera and for CSAMT methodology

    SciTech Connect

    Wannamaker, P.E.

    1994-06-01

    We have carried Out an extensive tensor CSAMT survey of the Sulphur Springs geothermal area, Valles Caldera, New Mexico. This survey, consisting of 45 high-quality sites, has been acquired by in support of Continental Scientific Drilling Program (CSDP) drillholes VC-2A and VC-2B. Two independent transmitter dipoles were energized for tensor measurements using a 30 kW generator placed approximately 13 km south of the VC-2B wellhead. The soundings in the Sulphur Springs area were arranged in four profiles to cross major structural features. The electric bipoles parallel to each profile were deployed contiguously to ensure against spatial aliasing of the impedance response corresponding to current flow across structural trends. The frequency range of acquisition was 4096 Hz down to 1 Hz for the central line, but only down to 4 Hz for most sites of the other lines. Data quality is high overall and is established by repeatability of measurements. Agreement between the CSAMT and available natural field MT data is very good over almost all the period range of overlap indicating that we are free of calibration problems and that far-field results are generally being obtained. Non plane-wave effects in the CSAMT around Sulphur Springs are apparent at 1 to 2 Hz, and perhaps slightly even at 4 Hz, however, which is near the bottom of our frequency range. CSAMT and MT data taken outside the Valles Caldera to the west were modeled in an attempt to compare resistivity structure exterior to the caldera to that within. With the availability of tensor CSAMT and MT data both inside and outside Valles Caldera, assumptions and methods of CSAMT are tested. In the Sulphur Springs area, near-coincident CSAMT and MT data near well VC -2B indicate that non-lane-wave effects in the apparent resistivity and impedance phase occure at a frequency near to that predicted from the resistivity structure local to the wester caldera.

  1. An Assessment of the Value of Full Tensor Gradient Gravity Data for Determining 3-D Structure in an Integrated Geophysical Interpretation of the Styldrift Region, Bushveld Complex, South Africa

    NASA Astrophysics Data System (ADS)

    Coomber, S. J.; Webb, S. J.

    2006-12-01

    The Bushveld Complex (2 060 2 054 Ma) is the largest known layered mafic intrusion in the world, at 7-9 km thick and covering approximately 65 000 km2, and is mined for its high grades of PGEs and chromium. Styldrift lies in a structurally complex region (due to the intrusion of the Pilanesburg, approximately 1 300 Ma) where dykes, faults, potholes and Iron-Rich Ultramafic Pegmatoids (IRUPs) present a problem to mining activities. Interpretation of 3-D seismic data, constrained by drill-holes, has produced a 3-D geological model in gOcad, which will assist in mine design and planning. A 1 km2 grid over the 3-D geological model has had high resolution ground gravity and ground magnetic data collected over it. Values of the vertical gravitational component were used to calculate the Full Tensor Gradient (FTG) gravity components, by first constructing the equivalent layer. Airborne FTG gravity data have been flown over the area, which may be compared to the calculated ground data, to test the accuracy of the FTG calculation. Aeromagnetic data over the region may also be compared to the ground data. The calculated FTG gravity data and magnetic data were used to run inversions (steepest descent and UBC algorithms) on the 3-D geological model. Highly reliable inversions of the FTG gravity data adjusted the lithological contacts of the 3-D geological model, constrained by seismic and borehole data, as well as densities of norites and anorthosites in the model, constrained by down-hole density measurements. A second 1 km2 grid, in close proximity to the first grid but with no corresponding seismic data, also had gravity and magnetic data (both ground and airborne) collected over it. A simple 3-D geological model was constructed, with lithological contacts and densities constrained by borehole data. Inversions of the calculated FTG gravity and magnetic data, and extending geological trends of the first geological model, lead to improvements in this geological model.

  2. Status of volcanic hazard studies for the Nevada Nuclear Waste Storage Investigations. Volume II

    SciTech Connect

    Crowe, B.M.; Wohletz, K.H.; Vaniman, D.T.; Gladney, E.; Bower, N.

    1986-01-01

    Volcanic hazard investigations during FY 1984 focused on five topics: the emplacement mechanism of shallow basalt intrusions, geochemical trends through time for volcanic fields of the Death Valley-Pancake Range volcanic zone, the possibility of bimodal basalt-rhyolite volcanism, the age and process of enrichment for incompatible elements in young basalts of the Nevada Test Site (NTS) region, and the possibility of hydrovolcanic activity. The stress regime of Yucca Mountain may favor formation of shallow basalt intrusions. However, combined field and drill-hole studies suggest shallow basalt intrusions are rare in the geologic record of the southern Great Basin. The geochemical patterns of basaltic volcanism through time in the NTS region provide no evidence for evolution toward a large-volume volcanic field or increases in future rates of volcanism. Existing data are consistent with a declining volcanic system comparable to the late stages of the southern Death Valley volcanic field. The hazards of bimodal volcanism in this area are judged to be low. The source of a 6-Myr pumice discovered in alluvial deposits of Crater Flat has not been found. Geochemical studies show that the enrichment of trace elements in the younger rift basalts must be related to an enrichment of their mantle source rocks. This geochemical enrichment event, which may have been metasomatic alteration, predates the basalts of the silicic episode and is, therefore, not a young event. Studies of crater dimensions of hydrovolcanic landforms indicate that the worst case scenario (exhumation of a repository at Yucca Mountain by hydrovolcanic explosions) is unlikely. Theoretical models of melt-water vapor explosions, particularly the thermal detonation model, suggest hydrovolcanic explosion are possible at Yucca Mountain. 80 refs., 21 figs., 5 tabs.

  3. The variogram and the simple kriging estimator: Useful tools to complement lithologic correlation in a complex fluvial depositional environment

    SciTech Connect

    Murphy, J.

    1995-12-31

    Three dimensional grid estimation has been combined with an interpretive model of fluvial deposition for correlating low permeability zones in the shallow subsurface. Improvement in correlation reliability was realized by combining hand drawn interpretive cross-sections (spotting local trends in grain size, CPT log signature, etc.) with cross-section maps of the geostatistical grid model. The site is a military installation where soil contamination is being mapped and quantified using three dimensional modeling techniques. The subsurface is a complex fluvial depositional environment with intermittent bedrock highs and more frequent calcite and Calcium/Iron related cementation. Hence, the problem of lithologic correlation occurred where the drillhole spacing became wider than the channel belt width or cemented materials prevented detailed sampling. The goals of the sampling and analysis plan called for sampling within the first continuous silt or clay unit in order to quantify the zone of greatest contaminant retention on its downward migratory path. This paper will describe a three dimensional correlation technique which employs geostatistical analysis of CPT hole data specifically coded by permeability indicator thresholds. The process yielded variogram ranges applied to a simple kriging estimator on a 3-dimensional grid block. Estimates of clay probability are then provided as output and overlaid with the geologists cross section interpretation. The marriage of these two tools was invaluable in that geostatistical estimates sometimes behaved contrary to the channel depositional process, while on the other hand, the geologists interpretation often failed to recognize data in the third dimension (i.e. off section CPT data).

  4. Assessment of the potential for karst in the Rustler Formation at the WIPP site.

    SciTech Connect

    Lorenz, John Clay

    2006-01-01

    This report is an independent assessment of the potential for karst dissolution in evaporitic strata of the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site. Review of the available data suggests that the Rustler strata thicken and thin across the area in depositional patterns related to lateral variations in sedimentary accommodation space and normal facies changes. Most of the evidence that has been offered for the presence of karst in the subsurface has been used out of context, and the different pieces are not mutually supporting. Outside of Nash Draw, definitive evidence for the development of karst in the Rustler Formation near the WIPP site is limited to the horizon of the Magenta Member in drillhole WIPP-33. Most of the other evidence cited by the proponents of karst is more easily interpreted as primary sedimentary structures and the localized dissolution of evaporitic strata adjacent to the Magenta and Culebra water-bearing units. Some of the cited evidence is invalid, an inherited baggage from studies made prior to the widespread knowledge of modern evaporite depositional environments and prior to the existence of definitive exposures of the Rustler Formation in the WIPP shafts. Some of the evidence is spurious, has been taken out of context, or is misquoted. Lateral lithologic variations from halite to mudstone within the Rustler Formation under the WIPP site have been taken as evidence for the dissolution of halite such as that seen in Nash Draw, but are more rationally explained as sedimentary facies changes. Extrapolation of the known karst features in Nash Draw eastward to the WIPP site, where conditions are and have been significantly different for half a million years, is unwarranted. The volumes of insoluble material that would remain after dissolution of halite would be significantly less than the observed bed thicknesses, thus dissolution is an unlikely explanation for the lateral variations from halite to mudstone and siltstone

  5. Drilling Addendum to Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California

    SciTech Connect

    Taylor, Gary C.; Bacon, C. Forrest; Chapman, Rodger H.; Chase, Gordon W.; Majmundar, Hasmukhrai H.

    1981-05-01

    This addendum report presents the results of the California Division of Mines and Geology (CDMG) drilling program at Calistoga, California, which was the final geothermal-resource assessment investigation performed under terms of the second year contract (1979-80) between the U.S. Department of Energy (DOE) and the CDMG under the State Coupled Program. This report is intended to supplement information presented in CDMG's technical report for the project year, ''Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California''. During the investigative phase of the CDMG's Geothermal Project, over 200 well-driller's reports were obtained from the Department of Water Resources (DWR). It was hoped that the interpretation and correlation of these logs would reveal the subsurface geology of the Upper Napa Valley and also provide a check for the various geophysical surveys that were performed in the course of the study. However, these DWR driller logs proved to be inadequate due to the brief, non-technical, and erroneous descriptions contained on the logs. As a result of the lack of useable drill-hole data, and because information was desired from,deeper horizons, it became evident that drilling some exploratory holes would be necessary in order to obtain physical evidence of the stratigraphy and aquifers in the immediate Calistoga area. Pursuant to this objective, a total of twelve sites were selected--four under jurisdiction of Napa County and eight under jurisdiction of the City of Calistoga. A moratorium is currently in existence within Napa County on most geothermal drilling, and environmental and time constraints precluded CDMG from obtaining the necessary site permits within the county. However, a variance was applied for and obtained from the City of Calistoga to allow CDMG to drill within the city limits. With this areal constraint and also funding limits in mind, six drilling sites were selected on the basis of (1

  6. Structurally controlled volcanism and contrasting types of mineralization, Tuscarora mining district and vicinity, Nevada

    SciTech Connect

    Wright, B.A. ); Boden, D.R.; Struhsacker, E.M.

    1993-04-01

    The Tuscarora district lies within an Eocene volcanic field that covers [approximately]800 km[sup 2] in the northern Tuscarora Mountains in northwest Elko County. Geologic mapping of [approximately]100 km[sup 2] at Tuscarora and vicinity and new K-Ar age determinations reveal a complex, rapidly evolving volcanic history. Volcanism began with construction of a poorly preserved andesitic stratovolcano(s) at 42+ Ma. Subsequently, the 7- by 10-km Mt. Blitzen graben developed between 41--42 Ma. The graben filled with the tuff of Mt. Blitzen. Graben subsidence occurred along NE to ENE and NNW to NW faults, and a variety of dikes and plugs, including the 39.8-Ma Mt. Neva granodiorite, locally intruded the bounding faults. Rocks of the graben strike NE, dip moderately to steeply, and are cut by penecontemporaneous NE-striking dikes, indicating that the graben formed in response to NW-SE-directed extension. Collapse of the rhyolitic Big Cottonwood Canyon caldera truncated the northern part of the Mt. Blitzen graben between 40.6 and 41.0 Ma. Rocks of the Mt. Blitzen graben range from silicic andesite to rhyodacite, whereas rocks of the Big Cottonwood Canyon caldera are rhyolite and high-silica rhyolite. Mineralization at Tuscarora occurs near the southeast margin of the Mt. Blitzen graben and mainly as quartz-adularia veins filling ENE, N, and NW faults. New K-Ar analyses on adularia from the Dexter and Grand Prize veins yield ages of 38.9 and 39.9 Ma, respectively. Although closely developed in space and time, the Ag-rich, base-metal-bearing mineralization, characterized by the Grand Prize vein, and the Au-rich, base-metal-poor Dexter vein zone likely represent separate, unrelated hydrothermal events. In general, alteration in the district, as observed in outcrops and drill-hole cuttings, changes from fault or fracture controlled in the north to more pervasive in the Dexter pit area and eastward under pediment.

  7. Prediction and discovery of new geothermal resources in the Great Basin: Multiple evidence of a large undiscovered resource base

    USGS Publications Warehouse

    Coolbaugh, M.F.; Raines, G.L.; Zehner, R.E.; Shevenell, L.; Williams, C.F.

    2006-01-01

    Geothermal potential maps by themselves cannot directly be used to estimate undiscovered resources. To address the undiscovered resource base in the Great Basin, a new and relatively quantitative methodology is presented. The methodology involves three steps, the first being the construction of a data-driven probabilistic model of the location of known geothermal systems using weights of evidence. The second step is the construction of a degree-of-exploration model. This degree-of-exploration model uses expert judgment in a fuzzy logic context to estimate how well each spot in the state has been explored, using as constraints digital maps of the depth to the water table, presence of the carbonate aquifer, and the location, depth, and type of drill-holes. Finally, the exploration model and the data-driven occurrence model are combined together quantitatively using area-weighted modifications to the weights-of-evidence equations. Using this methodology in the state of Nevada, the number of undiscovered geothermal systems with reservoir temperatures ???100??C is estimated at 157, which is 3.2 times greater than the 69 known systems. Currently, nine of the 69 known systems are producing electricity. If it is conservatively assumed that an additional nine for a total of 18 of the known systems will eventually produce electricity, then the model predicts 59 known and undiscovered geothermal systems are capable of producing electricity under current economic conditions in the state, a figure that is more than six times higher than the current number. Many additional geothermal systems could potentially become economic under improved economic conditions or with improved methods of reservoir stimulation (Enhanced Geothermal Systems).This large predicted geothermal resource base appears corroborated by recent grass-roots geothermal discoveries in the state of Nevada. At least two and possibly three newly recognized geothermal systems with estimated reservoir temperatures

  8. Using Archean and Paleoproterozoic Shales and Tillites as a Window into Crustal Evolution and Surface Conditions

    NASA Astrophysics Data System (ADS)

    Bindeman, I. N.; Bekker, A.; Zakharov, D. O.

    2014-12-01

    Precambrian shales and tillites have been insufficiently studied so far. We present oxygen and hydrogen isotope data for 103 bulk shale and tillites that were collected from drillholes on all continents from 3.2 to 1.4Ga. These samples have also been analyzed for total organic and inorganic carbon, total sulfur, δ13Corg values and by XRF for major and trace elements to calculate chemical index of alteration (CIA). Having uncompromised fresh samples from drillcores is a must for this kind of investigation. We have a particularly good coverage for the ca. 2.7-2.2 Ga time interval when Earth experienced 3-4 Snowball Earth glaciations associated with the rapid rise in atmospheric O2 and fluctuations in CO2, thus affecting weathering cycle and attainment of isotopic fractionation. All units have similar to Phanerozoic ranges in δ13Corg values (-23 to -33‰ PDB) and Corg content (0.1 to 10 wt. %). Compared to Phanerozoic shales, Precambrian shales have comparable ranges in δ18O values (+7 to +20‰), with slightly decreasing means with increasing age, and identical δ17O-δ18O slope (0.528). Shales in some drill holes display wide δ18O ranges over short stratigraphic intervals suggesting significant variability in the provenance. We however observe a significant, several permil downward shift and decrease in the range of δ18O values (7-9‰) in 2.2-2.5 Ga shales from several continents that are associated with the Paleoproterozoic glaciations. Scattered negative correlation of CIA with δ18O, for some of these shales broadly associated with the Paleoproterozoic glaciations suggest contact with glacial meltwater having ultra-low-δ18O values during deposition or diagenesis of these shales. The δD values of shales range from -50 to -75‰, and are comparable to Phanerozoic values, with the exception of the ~2.5-2.2 Ga shales that reach to -100‰. We also compare O isotope values of ultra-low-δ18O, +8 to -27‰ SMOW subglacial hydrothermal rocks recently discovered

  9. Transformations in shallow fault zones; evidence from fault rocks in young strike-slip systems.

    NASA Astrophysics Data System (ADS)

    van der Pluijm, B. A.; Schleicher, A. M.; Warr, L. N.

    2008-12-01

    Shallow fault rocks are typically interpreted in terms of brittle deformation features, such as fracture patterns, processes like cataclasis, and frictional properties from laboratory experiments. There is growing evidence from observations in natural rocks, however, that chemical and state transformations play an important, perhaps even a key role in shallow fault processes. Sheared mudrocks from a recent, active part of the San Andreas Fault (SAFOD) drillhole (3-3.3 km depth) show abundant, hydrous mixed-layer clay mineral phases. These hydrous phases formed during enhanced circulation of aqueous fluids along permeable fractures by low-temperature dissolution-precipitation reactions. Of particular significance is their occurrence as thin, nm- thick clay coatings on polished and striated fracture surfaces, similar in appearance to, but much smaller than slickensided surfaces commonly found in exhumed brittle fault rocks. These clay precipitates on secondary surfaces may be key to understanding creep and weak fault behavior, as they are restricted to displacement surfaces. Their occurrence also explains the low degree of preferred orientation, measured by X-ray texture goniometry, which is typical for clay gouges. Another area where transformations influence fault behavior at shallow crustal levels is by friction melting and associated neocrystallization. At seismic slip conditions, the formation of friction melts has been proposed from calculations and laboratory experiments. Few, unaltered natural laboratories are available, but the Alpine Fault of New Zealand provides opportunity for study in recent strike-slip activity. A suite of samples collected near a type locality show that brief melt generation occurred during a single period (with several pulses?) of displacement. Dating of these samples, in conjunction with thermal modeling, shows that pseudotachylyte formed at 3.5-5 km depth, which is just below SAFOD drilling depth. A general picture is emerging where

  10. Geophysical Setting of the Blue Mountain Geothermal Area, North-Central Nevada and its Relationship to a Crustal-Scale Fracture Associated with the Inception of the Yellowstone Hotspot

    NASA Astrophysics Data System (ADS)

    Ponce, D. A.; Bouligand, C.; Casteel, J.; Glen, J. M.; Watt, J. T.

    2009-12-01

    The Blue Mountain geothermal field, located about 35 km northwest of Winnemucca, Nevada, is situated along a prominent crustal-scale fracture interpreted from total-intensity aeromagnetic and gravity data. Aeromagnetic data indicate that this feature is related to the intrusion of mafic dikes, similar to the Northern Nevada Rift, and may be associated with the inception of the ~16 Ma Yellowstone Hotspot. This pre-existing large-scale crustal feature may have influenced the location of the geothermal prospect and the spatially associated epithermal gold deposit on the western flank of Blue Mountain. Other epithermal gold deposits in north-central Nevada are strongly correlated with this and other similar crustal-scale fractures associated with the Yellowstone Hotspot as well (Ponce and Glen, 2002). We investigate mafic dikes exposed along the western flank of Blue Mountain, and encountered in drill-holes DB-1 and DB-2 at depths of about 500 and 750 meters, respectively. The dikes are composed of gabbro to diorite and physical-property measurements indicate they have an average saturated-bulk density of 2852 kg/m3 and a moderately magnetic susceptibility of about 18.0 x 10-3 SI. Geologic investigations by Wyld (2002) and paleomagnetic investigations of the dikes indicate they are no younger than about 10 Ma and have a paleomagnetic direction consistent with a mid-Miocene age, suggesting they may be related to the inception of the Yellowstone Hotspot. Gravity, magnetic, and physical-property data were collected in the area in order to improve the regional data coverage, which was relatively sparse throughout this part of north-central Nevada, especially on pre-Cenozoic bedrock. These data are used to better constrain the geophysical setting of Blue Mountain. In particular, we invert gravity data to determine the geometry of the basins in the area which may yield important structural information. Simultaneous forward modeling of magnetic and gravity anomaly data is

  11. Withaferin A: a proteasomal inhibitor promotes healing after injury and exerts anabolic effect on osteoporotic bone.

    PubMed

    Khedgikar, V; Kushwaha, P; Gautam, J; Verma, A; Changkija, B; Kumar, A; Sharma, S; Nagar, G K; Singh, D; Trivedi, P K; Sangwan, N S; Mishra, P R; Trivedi, R

    2013-01-01

    supplementation improved trabecular micro-architecture of the long bones, increased biomechanical strength parameters of the vertebra and femur, decreased bone turnover markers (osteocalcin and TNFα) and expression of skeletal osteoclastogenic genes. It also increased new bone formation and expression of osteogenic genes in the femur bone as compared with vehicle groups (Sham) and ovariectomy (OVx), Bortezomib (known PI), injectible parathyroid hormone and alendronate (FDA approved drugs). WFA promoted the process of cortical bone regeneration at drill-holes site in the femur mid-diaphysis region and cortical gap was bridged with woven bone within 11 days of both estrogen sufficient and deficient (ovariectomized, Ovx) mice. Together our data suggest that WFA stimulates bone formation by abrogating proteasomal machinery and provides knowledge base for its clinical evaluation as a bone anabolic agent. PMID:23969857

  12. CARIBENORTE Project: Studying the deep structure of the NE Caribbean Plate

    NASA Astrophysics Data System (ADS)

    Carbo-Gorosabel, A.; Davila, J. M.; Cordoba Barba, D.; Granja, J. L.; Llanes Estrada, M.; Munoz Martin, A.; Druet, M.; Gomez, M.; Pazos, A.; Catalan, M.; ten Brink, U. S.; Payero, J.; Lopez, O.; Quijano, J.

    2009-12-01

    Despite the high number of studies carried out in the NE Caribbean there is still not a geodynamic model that is capable of integrating all of the local tectonic settings present in the area. The CaribeNorte Project aims to analyze the geodynamics of the area by studying the deep crustal structure of the North-eastern Caribbean Plate Boundary Zone across the Dominican Republic (DR) and by analyzing the morphostructure of the southern insular slope because most works have focused on the northern side of the arc. The main objectives of the project are: 1) to define the deep structure from north to south across the island arc and to test whether the Caribbean Plate’s interior is subducting beneath the DR, as has been hypothesized, 2) to analyse the deep and shallow structure of the northern Beata Ridge and to assess its origin and evolution, 3) to study the morphostructure of the zone of collision between the Muertos fold-and-thrust belt and the aseismic Beata Ridge, and 4) to evaluate the seismic and tsunami risk in the area. The new data was acquired during a research cruise held in the spring of 2009 aboard the Spanish R/V Hesperides. Swath bathymetry was obtained covering an area of 34.460 km2 in the south of the DR, overlapping by the east with data from our previous cruise Geoprico-Do. Along the track lines we have continuously collected gravity and magnetic data and high-resolution seismic profiles (TOPAS system). The active seismic experiment consisted on 3 deep seismic soundings profiles with a total of 16 OBS, deployed from the DR’s ship Orion, and 340 seismic land stations. For the deep seismic experiment the R/V Hesperides was shooting every 90 s with airguns having a total power of 3.850 ci. In addition, the Dominican Republic’s DGM collaborated with 3 drill-hole explosions on-shore. The five seismic profiles have a total of 980 km offshore and 650 km onshore, running across the Bahamas Carbonate platform, the DR island along two transects, the

  13. A Hydrostrat Model and Alternatives for Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainer Mesa-Shoshone Mountain, Nye County, Nevada

    SciTech Connect

    NSTec Geotechnical Sciences Group

    2007-03-01

    The three-dimensional hydrostratigraphic framework model for the Rainier Mesa-Shoshone Mountain Corrective Action Unit was completed in Fiscal Year 2006. The model extends from eastern Pahute Mesa in the north to Mid Valley in the south and centers on the former nuclear testing areas at Rainier Mesa, Aqueduct Mesa, and Shoshone Mountain. The model area also includes an overlap with the existing Underground Test Area Corrective Action Unit models for Yucca Flat and Pahute Mesa. The model area is geologically diverse and includes un-extended yet highly deformed Paleozoic terrain and high volcanic mesas between the Yucca Flat extensional basin on the east and caldera complexes of the Southwestern Nevada Volcanic Field on the west. The area also includes a hydrologic divide between two groundwater sub-basins of the Death Valley regional flow system. A diverse set of geological and geophysical data collected over the past 50 years was used to develop a structural model and hydrostratigraphic system for the model area. Three deep characterization wells, a magnetotelluric survey, and reprocessed gravity data were acquired specifically for this modeling initiative. These data and associated interpretive products were integrated using EarthVision{reg_sign} software to develop the three-dimensional hydrostratigraphic framework model. Crucial steps in the model building process included establishing a fault model, developing a hydrostratigraphic scheme, compiling a drill-hole database, and constructing detailed geologic and hydrostratigraphic cross sections and subsurface maps. The more than 100 stratigraphic units in the model area were grouped into 43 hydrostratigraphic units based on each unit's propensity toward aquifer or aquitard characteristics. The authors organized the volcanic units in the model area into 35 hydrostratigraphic units that include 16 aquifers, 12 confining units, 2 composite units (a mixture of aquifer and confining units), and 5 intrusive confining

  14. Gravimetric response of water table fluctuations in the Sahelian Diffa site (East Niger): local effects including poro-elasticity

    NASA Astrophysics Data System (ADS)

    Hector, B.; Genthon, P.; Le Coz, M.; Hinderer, J.; Chalikakis, K.; Descloitres, M.

    2010-12-01

    observed gravimetic signal and the results of the global hydrological model GLDAS are offset with respect to the piezometric one. In order to assess the influence of local effects, the groundwater level is modeled with the USGS finite-difference ModFlow code using different properties sets of the aquifer deduced from statistical analysis of drill-holes data. Poroelasticity effects resulting from variable saturation of the clay layers observed near the water level on the Bagara site are assessed. The ability of gravity data for monitoring annual and long term water level changes in the uppermost aquifer is then discussed.

  15. Stress and strain around a multiply reactivated deep-seated fault zone and its impact on a potential geothermal reservoir - The Freiburg-Bonndorf-Bodensee fault zone

    NASA Astrophysics Data System (ADS)

    Egli, Daniel; Madritsch, Herfried; Ibele, Tobias; Mosar, Jon; Vietor, Tim

    2014-05-01

    The Swiss and German Molasse Basin is generally of high geo-economical interest as it is considered to host potential reservoirs for natural gas and geothermal energy production, as well as sites for radioactive waste disposal and CO2 storage. Its successful exploration and eventually exploitation requires detailed understanding of its deep underground in particular its structural characteristics. Information of the rocks underlying the up to km thick Molasse sediments is mainly available from drillhole and seismic data. Outcrops of Mesozoic and Paleozoic sediments as well as the crystalline basement that could provide additional information on structural geological characteristics are very rare and mostly restricted to the borders of the basin. This study focuses on the eastern part of the Freiburg-Bonndorf-Bodensee Fault Zone (FBBFZ; e.g. Paul 1948, Carlé 1955), a roughly 100 km long fault system, which runs approximately from the Kaiserstuhl in the Upper Rhein Graben across the Black Forest Massif to the Lake Constance. Its extensive present day surface trace allows to study the fault zone as it cuts through a wide range of lithologies from the Variscan basement of the Black Forest to the Tertiary sediments of the Molasse west of Lake Constance. As such, it can serve as natural analogue for the characterization of fault structures in the subsurface of the Molasse Basin. The Randen Fault is a well-exposed NW-SE trending fault segment of the FBBFZ, situated in NE Switzerland and SW Germany. In the field, as well as in seismic sections the structure shows the characteristics of a normal fault but there are indications for a dextral transcurrent overprint. We presents a kinematic analysis of outcrop scale fracture systems collected along the various segments of the FBBFZ with a focus on the Randen Fault segment. The results indicate a perturbation of the regional fracture characteristics and the paleostress pattern in the vicinity of the fault zone. A recently

  16. Ammonium illite at the Jerritt Canyon district and Goldstrike property, Nevada: Its spatial distribution and significance in the exploration of Carlin-type deposits

    NASA Astrophysics Data System (ADS)

    Mateer, Melissa A.

    Ammoniated hydrothermal fluids interact with potassium-bearing minerals in wall rock material to form ammonium illite alteration patterns along fluid conduits associated with Carlin-type gold deposits. These same fluids transport gold which is disseminated into favorable host rock. Thus, ammonium illite serves as an exploration tool for locating Carlin-type gold deposits. Ammonium illite alteration patterns at the Waterpipe Canyon area (Jerritt Canyon district) and a similar alteration pattern at the North Screamer deposit (on the Goldstrike property) were mapped and characterized using a combination of remote sensing, GIS, short-wave infrared spectroscopy, and 3-D modeling. Four classes of illite (sericitic, phengitic, potassic, and mixed illitic clays are identified based on the precise wavelength position of the main AlOH spectral absorption feature near 2200 nm. Ammonium occurs primarily in sericitic illite and phengitic illite. Phengitic illite, in particular, is considered a useful indicator of hydrothermal activity and can be a useful guide for gold exploration. On the surface, ammonium illite forms an alteration pattern that mimics hematite alteration in proximity to structure. Both minerals are also associated with anomalous gold thus, providing evidence that ammoniated fluids migrated along the same fluid conduits that deposited gold. The pathways in which fluids migrated are mapped from drill-hole and surface samples. Associated alteration was traced from the deposit to the surface by modeling the distribution of ammonium illite in wall rock material along mapped faults. Three dimensional modeling establishes that ammonium illite forms near gold mineralization and (as alteration halos) around fluid conduits on surface. Hyperspectral imagery was classified using ENVI hyperspectral image-analysis software to identify individual pixels that most closely match the spectral character of ammonium illite. MNF transformation was applied to the image and a false

  17. Sedimentary basins reconnaissance using the magnetic Tilt-Depth method

    USGS Publications Warehouse

    Salem, A.; Williams, S.; Samson, E.; Fairhead, D.; Ravat, D.; Blakely, R.J.

    2010-01-01

    basement). The method is especially valuable as a reconnaissance tool in regions where drillhole or seismic information are either scarce, lacking, or ambiguous.

  18. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multifrequency EM

    NASA Astrophysics Data System (ADS)

    Hoppmann, Mario; Hunkeler, Priska A.; Hendricks, Stefan; Kalscheuer, Thomas; Gerdes, Rüdiger

    2016-04-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise, accumulate beneath nearby sea ice, and subsequently form a several meter thick, porous sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator of the health of an ice shelf. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions within the platelet layer using Archie's Law. The thickness results agreed well with drillhole validation datasets within the uncertainty range, and the ice-volume fraction yielded results comparable to other studies. Both parameters together enable an estimation of the total ice volume within the platelet layer, which was found to be comparable to the volume of landfast sea ice in this region, and corresponded to more than a quarter of the annual basal melt volume of the nearby Ekström Ice Shelf. Our findings show that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties, with important implications for research into ocean/ice-shelf/sea-ice interactions. However, a successful application of this

  19. Simulation Study of Micro Particles Behavior in Fluid Flow Using Lattice Boltzmann Method

    NASA Astrophysics Data System (ADS)

    Miyoshi, T.; Yamada, Y.; Matsuoka, T.

    2004-12-01

    Evaluation of underground hydraulic characteristics has been a key issue not only for hydrogeology but for various fields of geo-engineering. We have been investigating hydraulic properties, such as permeability, of fractures and porous rocks using a 3D lattice Boltzmann method (LBM) for recent several years. In this paper, we propose a coupling method of LBM and DEM (distinct element method) to incorporate dynamic interaction of fluid flow and particles. This coupling technique brings new insights into the effect of micro particles in the hydraulic properties, such that migration and sedimentation of solid particles remarkably decreases permeability. We present two simulation examples; I) sedimentation of micro particles by the gravity in dead water, II) behaviour of micro particles in fluid flow through a porous media. In the simulation-I, surface geometry of the particle assembly shows a gentle 'sag' with a subtle subsidence at its center, suggesting that the upward fluid expulsion causes slightly uplifted geometry. Such geometry of particles can be commonly seen in natural sedimentary rocks that deformed due to fluid expulsion at its unconsolidated stages. The simulation-II clearly showed some conditions of pore throat plugging by the micro particles. The fluid flow pattern should be significantly affected by the moving particles, as well as the pressure difference (an input parameter). The percolation distance of solid particles was well controlled with the pressure difference and throat geometries. We concluded that the coupling simulation of LBM and DEM has extremely high potential to investigate the behavior of solid and fluid interactions. The technique can simulate permeability changes precisely, that are affected by dynamic or physical factors such as compaction. Fluid flow simulations with the technique can be directly applied for plugging of solid particles within a reservoir, which is significant for petroleum production and drill-hole completion. The

  20. Geothermal modelling of faulted metamorphic crystalline crust: a new model of the Continental Deep Drilling Site KTB (Germany)

    NASA Astrophysics Data System (ADS)

    Szalaiová, Eva; Rabbel, Wolfgang; Marquart, Gabriele; Vogt, Christian

    2015-11-01

    The area of the 9.1-km-deep Continental Deep Drillhole (KTB) in Germany is used as a case study for a geothermal reservoir situated in folded and faulted metamorphic crystalline crust. The presented approach is based on the analysis of 3-D seismic reflection data combined with borehole data and hydrothermal numerical modelling. The KTB location exemplarily contains all elements that make seismic prospecting in crystalline environment often more difficult than in sedimentary units, basically complicated tectonics and fracturing and low-coherent strata. In a first step major rock units including two known nearly parallel fault zones are identified down to a depth of 12 km. These units form the basis of a gridded 3-D numerical model for investigating temperature and fluid flow. Conductive and advective heat transport takes place mainly in a metamorphic block composed of gneisses and metabasites that show considerable differences in thermal conductivity and heat production. Therefore, in a second step, the structure of this unit is investigated by seismic waveform modelling. The third step of interpretation consists of applying wavenumber filtering and log-Gabor-filtering for locating fractures. Since fracture networks are the major fluid pathways in the crystalline, we associate the fracture density distribution with distributions of relative porosity and permeability that can be calibrated by logging data and forward modelling of the temperature field. The resulting permeability distribution shows values between 10-16 and 10-19 m2 and does not correlate with particular rock units. Once thermohydraulic rock properties are attributed to the numerical model, the differential equations for heat and fluid transport in porous media are solved numerically based on a finite difference approach. The hydraulic potential caused by topography and a heat flux of 54 mW m-2 were applied as boundary conditions at the top and bottom of the model. Fluid flow is generally slow and

  1. Geomechanical models of impact cratering: Puchezh-Katunki structure

    NASA Technical Reports Server (NTRS)

    Ivanov, B. A.

    1992-01-01

    Impact cratering is a complex natural phenomenon that involves various physical and mechanical processes. Simulating these processes may be improved using the data obtained during the deep drilling at the central mound of the Puchezh-Katunki impact structure. A research deep drillhole (named Vorotilovskaya) has been drilled in the Puchezh-Katunki impact structure (European Russia, 57 deg 06 min N, 43 deg 35 min E). The age of the structure is estimated at about 180 to 200 m.y. The initial rim crater diameter is estimated at about 40 km. The central uplift is composed of large blocks of crystalline basement rocks. Preliminary study of the core shows that crystalline rocks are shock metamorphosed by shock pressure from 45 GPa near the surface to 15-20 GPa at a depth of about 5 km. The drill core allows the possibility of investigating many previously poorly studied cratering processes in the central part of the impact structure. As a first step one can use the estimates of energy for the homogeneous rock target. The diameter of the crater rim may be estimated as 40 km. The models elaborated earlier show that such a crater may be formed after collapse of a transient cavity with a radius of 10 km. The most probable range of impact velocities from 11.2 to 30 km/s may be inferred for the asteroidal impactor. For the density of a projectile of 2 g/cu cm the energy of the impact is estimated as 1E28 to 3E28 erg. In the case of vertical impact, the diameter of an asteroidal projectile is from 1.5 to 3 km for the velocity range from 11 to 30 km/s. For the most probable impact angle of 45 deg, the estimated diameter of an asteroid is slightly larger: from 2 to 4 km. Numerical simulation of the transient crater collapse has been done using several models of rock rheology during collapse. Results show that the column at the final position beneath the central mound is about 5 km in length. This value is close to the shock-pressure decay observed along the drill core. Further

  2. Sampling and analysis of chemical element concentration distribution in rock units and orebodies

    NASA Astrophysics Data System (ADS)

    Agterberg, F. P.

    2012-01-01

    other orebody datasets (Whalesback copper deposit, Witwatersrand goldfields and Black Cargo titanium deposit). Additionally, it is discussed that nugget effects exist in a binary series of alternating mostly gneiss and metabasite previously derived from KTB borehole velocity and lithology logs, and within a series of 2796 copper concentration values from this same drill-hole.

  3. 3d model for site effect assessment at Nice (France)

    NASA Astrophysics Data System (ADS)

    Bertrand, E.; Courrioux, G.; Bourgine, B.; Bour, M.; Guillen, A.; Mouroux, P.; Devaux, E.; Duval, A. M.

    2003-04-01

    Assessment of lithologic site effects is based on an accurate knowledge of properties and geometry of superficial geological formations, i.e. ideally a 3D-4G subsurface model (Geology, Geomorphology, Geophysics, Geotechnics). Such a model has been achieved using a 3D geomodeler ("Geological Editor" developed at BRGM) that allows building 3D volumes of geological formations starting from drill-holes data, sections, and geological maps. This software uses a pseudo-stratigraphic pile in order to reproduce geological history and structural relationships (erosion, deposit). The interpolation is achieved through a 3D potential field. A geostatistical formulation allows to consider data points of a geological limit as equipotential, and sructural dips as gradient inputs for the 3D field interpolation. Then isosurfaces corresponding to each limit are combined using formation relationships to provide volumic models of geological formations. The first task was to identify the relevant geological formations underlying in Nice area. In a first approach Mesozoic bedrock, Pliocene bedrock, and Quaternary alluvial deposits have been distinguished considering their seismic properties. Then alluvions have been subdivided into 9 groups according to their lithology and granulometry. Modelling has been performed considering 2 major erosion surfaces, post-Mesozoic and post-Pliocene. The succession of Quaternary alluviums have been considered as "onlap deposits". Given adjacent lithologies contained in maps and drill holes, these relations lead to logical identification of the roof of formations to be interpolated. The distribution of modeled geological formations can be visualised in 3 dimensions or in 2D sections. Besides the visual interest of 3D representations, the model is first used to build a series of earth columns over a 50m/50m 2D grid. A statistical analysis allowed to identify 73 existing configurations in the Nice district area. Among these, only 15 configurations

  4. Relationship between normal faulting and volcanic activity in the Taranaki backarc basin, New Zealand

    NASA Astrophysics Data System (ADS)

    Giba, M.; Walsh, J. J.; Nicol, A.

    2009-04-01

    Volcanoes and normal faults are, by definition, both present within volcanic rifts. Despite this association the causal relationships between volcanism and normal faulting can be unclear and are poorly understood. One of the principal challenges for investigations of the links between faulting and volcanic activity, is the definition of the detailed temporal relationships between these two processes. The northern Taranaki Basin, which benefits from excellent seismic (2D and 3D) and drillhole coverage, provides the basis for a detailed study of volcanism and faulting over the last ca 15 Myr. Most of the basin is characterised by sedimentation rates which exceed fault displacement rates, a condition which permits displacement backstripping of these syn-sedimentary growth faults. The timing of a suite of mostly andesitic submarine volcanoes has been constrained by interdigitation of the volcanic cones with basinal sedimentary rocks. Eleven dated horizons within the ca 15 Myr and younger stratigraphy together with mapping provide a means of examining the temporal and spatial links between fault and volcanic activity within the basin. The northern Taranaki Basin has a multiphase deformation history, with extension during the Late Cretaceous to Mid Eocene (ca 80-45 Ma), followed by contraction in the Late Eocene to Early Miocene (ca 40-18 Ma) and then by Mid Miocene to recent back arc extension (ca 15-0 Ma). The youngest phase of extensional faulting initiated in the north and west of the basin and migrated to the southeast where present activity is focused. Volcanic activity also commenced in the north during the Mid Miocene and migrated towards the south and east. Volcanism and backarc extension are driven by subduction of the Pacific plate along the Hikurangi margin. The southward and eastward migration of both faulting and volcanic activity is attributed to the steepening and rotation of the subducting slab beneath the Taranaki Basin. Despite the common origin of

  5. How clays weaken faults.

    NASA Astrophysics Data System (ADS)

    van der Pluijm, Ben A.; Schleicher, Anja M.; Warr, Laurence N.

    2010-05-01

    The weakness of upper crustal faults has been variably attributed to (i) low values of normal stress, (ii) elevated pore-fluid pressure, and (iii) low frictional strength. Direct observations on natural faults rocks provide new evidence for the role of frictional properties on fault strength, as illustrated by our recent work on samples from the San Andreas Fault Observatory at Depth (SAFOD) drillhole at Parkfield, California. Mudrock samples from fault zones at ~3066 m and ~3296 m measured depth show variably spaced and interconnected networks of displacement surfaces that consist of host rock particles that are abundantly coated by polished films with occasional striations. Transmission electron microscopy and X-ray diffraction study of the surfaces reveal the occurrence of neocrystallized thin-film clay coatings containing illite-smectite (I-S) and chlorite-smectite (C-S) phases. X-ray texture goniometry shows that the crystallographic fabric of these faults rocks is characteristically low, in spite of an abundance of clay phases. 40Ar/39Ar dating of the illitic mix-layered coatings demonstrate recent crystallization and reveal the initiation of an "older" fault strand (~8 Ma) at 3066 m measured depth, and a "younger" fault strand (~4 Ma) at 3296 m measured depth. Today, the younger strand is the site of active creep behavior, reflecting continued activation of these clay-weakened zones. We propose that the majority of slow fault creep is controlled by the high density of thin (< 100nm thick) nano-coatings on fracture surfaces, which become sufficiently smectite-rich and interconnected at low angles to allow slip with minimal breakage of stronger matrix clasts. Displacements are accommodated by localized frictional slip along coated particle surfaces and hydrated smectitic phases, in combination with intracrystalline deformation of the clay lattice, associated with extensive mineral dissolution, mass transfer and continued growth of expandable layers. The

  6. How clays affect fault strength and slip behavior: Lessons from SAFOD

    NASA Astrophysics Data System (ADS)

    van der Pluijm, B. A.; Schleicher, A. M.; Warr, L.

    2010-12-01

    The strength and slip behavior of upper crustal faults has been attributed to (i) values of normal stress, (ii) pore-fluid pressure, and (iii) frictional properties. Direct observations on natural fault rocks provide compelling evidence for the role of localized neomineralization, as demonstrated by our work on samples from the San Andreas Fault Observatory at Depth (SAFOD) drillhole at Parkfield, California. Mudrock samples from fault zones at ~3066 m and ~3296 m measured depth (MD) show variably spaced and interconnected networks of displacement surfaces that consist of host rock particles that are abundantly coated by polished films with occasional striations. Transmission electron microscopy and X-ray diffraction study of the surfaces reveal the occurrence of neocrystallized thin-film clay coatings containing illite-smectite (I-S) and chlorite-smectite (C-S) phases. X-ray texture goniometry shows that the clay crystallographic fabric of these faults rocks is characteristically low, in spite of an abundance of clay phases. 40Ar/39Ar dating of the illitic coatings demonstrate recent crystallization and reveals the initiation of an “older” fault strand (~8 Ma) at 3066 m MD, and a “younger” fault strand (~4 Ma) at 3296 m MD. Today, the younger strand is the site of active creep behavior, reflecting continued activation of clay-weakened zones. We propose that fault creep is controlled by the localization of thin (< 100nm thick) nanocoatings on fracture surfaces that are sufficiently smectite-rich and interconnected to allow slip with minimal breakage of stronger matrix clasts. Displacements are accommodated by frictional slip along coated particle surfaces, in combination with intracrystalline deformation of the mineral lattice, resulting from crystal dissolution, mass transfer and growth of expandable clays. The highly localized concentration of both I-S and C-S minerals does not require volumetrically large mass transfer. A scenario is proposed where

  7. Fluid-deposited graphitic inclusions in quartz: Comparison between KTB (German Continental Deep-Drilling) core samples and artificially reequilibrated natural inclusions

    USGS Publications Warehouse

    Pasteris, J.D.; Chou, I.-Ming

    1998-01-01

    We used Raman microsampling spectroscopy (RMS) to determine the degree of crystallinity of minute (2-15 ??m) graphite inclusions in quartz in two sets of samples: experimentally reequilibrated fluid inclusions in a natural quartz grain and biotite-bearing paragneisses from the KTB deep drillhole in SE Germany. Our sequential reequilibration experiments at 725??C on initially pure CO2 inclusions in a quartz wafer and the J. Krautheim (1993) experiments at 900-1100??C on organic compounds heated in gold or platinum capsules suggest that, at a given temperature, (1) fluid-deposited graphite will have a lower crystallinity than metamorphosed organic matter and (2) that the crystallinity of fluid-deposited graphite is affected by the composition of the fluid from which it was deposited. We determined that the precipitation of more-crystalline graphite is favored by lower fH2 (higher fO2), and that the crystallinity of graphite is established by the conditions (including gas fugacities) that pertain as the fluid first reaches graphite saturation. Graphite inclusions within quartz grains in the KTB rocks show a wide range in crystallinity index, reflecting three episodes of carbon entrapment under different metamorphic conditions. Isolated graphite inclusions have the spectral properties of totally ordered, completely crystalline graphite. Such crystallinity suggests that the graphite was incorporated from the surrounding metasedimentary rocks, which underwent metamorphism at upper amphibolite-facies conditions. Much of the fluid-deposited graphite in fluid inclusions, however, shows some spectral disorder. The properties of that graphite resemble those of experimental precipitates at temperatures in excess of 700??C and at elevated pressures, suggesting that the inclusions represent precipitates from C-O-H fluids trapped under conditions near those of peak metamorphism at the KTB site. In contrast, graphite that is intimately associated with chlorite and other

  8. Stimulating angiogenesis mitigates the unloading-induced reduction in osteogenesis in early-stage bone repair in rats

    PubMed Central

    Matsumoto, Takeshi; Sato, Shota

    2015-01-01

    Accelerating fracture healing during bed rest allows early mobilization and avoids prolonged fracture healing times. We tested the hypothesis that stimulating angiogenesis with deferoxamine (DFO) mitigates the unloading-induced reduction in early-stage bone repair. Rats aged 12 weeks were subjected to cortical drilling on their tibial diaphysis under anesthesia and treated with hindlimb unloading (HU), HU and DFO administration (DFOHU), or weight bearing (WB) for 5 or 10 days (HU5/10, DFOHU5/10, WB5/10; n = 8 per groups) until sacrifice for vascular casting with a zirconium dioxide-based contrast agent. Taking advantage of its absorption discontinuity at the K-absorption edge, vascular and bone images in the drill-hole defects were acquired by synchrotron radiation subtraction CT. Bone repair was reduced in HU rats. The bone volume fraction (B.Vf) was 88% smaller in HU5 and 42% smaller in HU10 than in WB5/10. The bone segment densities (B.Seg) were 97% smaller in HU5 and 141% larger in HU10 than in WB5/10, and bone thickness (B.Th) was 38% smaller in HU10 than in WB10. The vascular volume fraction (V.Vf) was 35% and the mean vessel diameter (V.D) was 13% smaller in HU10 than in WB10. When compared according to categorized vessel sizes, V.Vf in the diameter ranges 20–30, 30–40, and >40 μm were smaller in HU10 than in WB10, and V.Seg in the diameter range >40 μm was smaller in HU10 than in WB10. In contrast, there was no difference in B.Vf between DFOHU5/10 and WB5/10 and in V.Vf between DFOHU10 and WB10, though B.Seg remained 86% smaller in DFOHU5 and 94% larger in DFOHU10 than in WB5/10, and B.Th and V.D were 23% and 14% lower in DFOHU10 than in WB10. Vessel size-specific V.Vf in the diameter ranges 10–20 and 20–30 μm was larger in DFOHU5 than in HU5. In conclusion, the enhanced angiogenic ingrowth mitigates the reduction in bone repair during mechanical unloading. PMID:25780087

  9. Geostatistical Analysis of Spatial Variability of Mineral Abundance and Kd in Frenchman Flat, NTS, Alluvium

    SciTech Connect

    Carle, S F; Zavarin, M; Pawloski, G A

    2002-11-01

    LLNL hydrologic source term modeling at the Cambric site (Pawloski et al., 2000) showed that retardation of radionuclide transport is sensitive to the distribution and amount of radionuclide sorbing minerals. While all mineralogic information available near the Cambric site was used in these early simulations (11 mineral abundance analyses from UE-5n and 9 from RNM-l), these older data sets were qualitative in nature, with detection limits too high to accurately measure many of the important radionuclide sorbing minerals (e.g. iron oxide). Also, the sparse nature of the mineral abundance data permitted only a hypothetical description of the spatial distribution of radionuclide sorbing minerals. Yet, the modeling results predicted that the spatial distribution of sorbing minerals would strongly affect radionuclide transport. Clearly, additional data are needed to improve understanding of mineral abundances and their spatial distributions if model predictions in Frenchman Flat are to be defensible. This report evaluates new high-resolution quantitative X-Ray Diffraction (XRD) data on mineral distributions and their abundances from core samples recently collected from drill hole ER-5-4. The total of 94 samples from ER-5-4 were collected at various spacings to enable evaluation of spatial variability at a variety of spatial scales as small as 0.3 meters and up to hundreds of meters. Additional XRD analyses obtained from drillholes UE-Sn, ER-5-3, and U-11g-1 are used to augment evaluation of vertical spatial variability and permit some evaluation of lateral spatial variability. A total of 163 samples are evaluated. The overall goal of this study is to understand and characterize the spatial variation of sorbing minerals in Frenchman Flat alluvium using geostatistical techniques, with consideration for the potential impact on reactive transport of radionuclides. To achieve this goal requires an effort to ensure that plausible geostatistical models are used to

  10. Stress feature interpretation from ICDP drill holes to constrain the orientations of the three principal stresses: Snake River Plain (USA)

    NASA Astrophysics Data System (ADS)

    Pierdominici, Simona; Kück, Jochem; Harms, Ulrich; Schmitt, Douglas R.

    2016-04-01

    Downhole data from drilled holes provide a unique opportunity to identify wellbore failure and understand physical properties of the deep sediments and rocks. In the framework of the ICDP (International Continental Scientific Drilling Program) we have obtained and analysed a set of geophysical logging data of two deep boreholes (Kimama and Kimberly) in the Snake River Plain in southern Idaho for the ICDP Hot Spot project. The Snake River Plain represents the track of a deep-seated mantle hotspot that has thinned the lithosphere and fuelled the intrusion of up to 10 km of hot basaltic-rhyolitic magma into the lower and middle crust. This area represents the ideal place for geothermal exploration and exploitation. For that a study of the complete state of stress in this region becomes a key point to know and understand the distribution of fractures and failures and how they can influence the permeability of the Hot Spot geothermal reservoir. Processed acoustic borehole images acquired along two boreholes detect a variety of natural and drilling induced features on the borehole wall, including bedding, fractures and breakouts. Three primary types of stress-induced drillhole indicators, breakouts, petal centre-line fractures and tensile fractures, were analysed in detail in order to define the orientation of the present-day stress state. Borehole breakouts are stress-induced elongations of a borehole cross section and on borehole images they appear as dark features and in some cases, incipient breakouts have been identified by conjugate shear fractures, where no spalling of the borehole wall has occurred. The drilling induced tensile fractures appear as dark electrically conductive features, with a strike parallel to the direction of the far-field greatest horizontal stress. They can be differentiated from natural fractures because they do not cross the borehole, do not form complete sinusoids shape on BHTV images and show a discontinuous nature. On the contrary the

  11. Current Research at the Endeavour Ridge 2000 Integrated Studies Site

    NASA Astrophysics Data System (ADS)

    Butterfield, D. A.; Kelley, D. S.; Ridge 2000 Community, R.

    2004-12-01

    Integrated geophysical, geological, chemical, and biological studies are being conducted on the Endeavour segment with primary support from NSF, the W.M. Keck Foundation, and NSERC (Canada). The research includes a seismic network, physical and chemical sensors, high-precision mapping and time-series sampling. Several research expeditions have taken place at the Endeavour ISS in the past year. In June 2003, an NSF-sponsored cruise with R.V. al T.G.Thompson/ROV al Jason2 installed microbial incubators in drill-holes in the sides of active sulfide chimneys and sampled rocks, fluids, and microbes in the Mothra and Main Endeavour Field (MEF). In July 2003, with al Thompson/Jason2, an NSF-LEXEN project at Baby Bare on Endeavour east flank conducted sampling through seafloor-penetrating probes, plus time-series sampling of fluids, microbes, and rocks at the MEF. In September 2003, with al Thompson/ROV al ROPOS, the Keck Proto-Neptune project installed a seismic network consisting of 1 broadband and 7 short-period seismometers, installation of chemical/physical sensors and time-series samplers for chemistry and microbiology in the MEF and Clam Bed sites, collection of rocks, fluids, animals, and microbes. In May/June 2004, an NSF-sponsored al Atlantis/Alvin cruise recovered sulfide incubators installed in 2003, redeployed a sulfide incubator, mapped MEF and Mothra vent fields with high-resolution Imagenix sonar, sampled fluids from MEF, Mothra, and Clam Bed, recovered year-long time-series fluid and microbial samplers from MEF and Clam Bed, recovered and installed hot vent temperature-resistivity monitors, cleaned up the MEF and deployed new markers at major sulfide structures. In August 2004, there were two MBARI/Keck-sponsored cruises with R.V. al Western Flyer/ROV al Tiburon. The first cruise completed the seismic network with addition of two more broadband seismometers and serviced all 7 short-period seismometers. al Tiburon then performed microbial and chemical

  12. Mapping hyper-extended rift systems offshore and onshore: insights from the Bay of Biscay- Western Pyrenees

    NASA Astrophysics Data System (ADS)

    Tugend, Julie; Manatschal, Gianreto; Kusznir, Nicolas J.; Masini, Emmanuel; Thinon, Isabelle

    2013-04-01

    Research conducted at present-day passive continental margins shows more varied crustal architectures than previously assumed. New seismic data together with drill-holes have revealed the occurrence of extremely thinned continental crust in the distal part of the margin as well as exhumed serpentinised sub-continental mantle oceanwards. In addition the understanding of the formation of hyper-extended rift systems has also greatly benefited from the study of onshore analogs preserved in mountain belts. The Bay of Biscay and Western Pyrenees correspond to a Lower Cretaceous rift system leading to the development of hyper-extended domains and ultimately oceanic crust in the Bay of Biscay. This domain represents one of the best natural laboratories to study the formation processes and evolution of hyper-extended domains. During late Cretaceous compression, these rifted domains were inverted resulting in the present-day Pyrenean mountain belt. In this contribution, we present a new paleogeographic map of the Bay of Biscay-Pyrenean rift system. We integrate results from previous works and new work using different mapping methods to distinguish distinctive crustal domains related to hyper-extended systems both offshore and onshore. We combine seismic interpretations with gravity anomaly inversion and residual depth anomaly analysis to distinguish the different crustal domains across the offshore margin. Onshore, we use an innovative approach based on observations from present-day rifted margin architecture associated with classical field work to map the former hyper-extended domains. Another outcome of this work is the creation of a crustal thickness map using gravity inversion linking offshore and onshore domains from the Bay of Biscay to that of the Western-Pyrenees. This multidisciplinary approach enables us to investigate the spatial and temporal evolution of the Bay of Biscay rift system with the aim of better understanding the formation of hyper-extended domains

  13. Neurotrophin-3 Induces BMP-2 and VEGF Activities and Promotes the Bony Repair of Injured Growth Plate Cartilage and Bone in Rats.

    PubMed

    Su, Yu-Wen; Chung, Rosa; Ruan, Chun-Sheng; Chim, Shek Man; Kuek, Vincent; Dwivedi, Prem P; Hassanshahi, Mohammadhossein; Chen, Ke-Ming; Xie, Yangli; Chen, Lin; Foster, Bruce K; Rosen, Vicki; Zhou, Xin-Fu; Xu, Jiake; Xian, Cory J

    2016-06-01

    Injured growth plate is often repaired by bony tissue causing bone growth defects, for which the mechanisms remain unclear. Because neurotrophins have been implicated in bone fracture repair, here we investigated their potential roles in growth plate bony repair in rats. After a drill-hole injury was made in the tibial growth plate and bone, increased injury site mRNA expression was observed for neurotrophins NGF, BDNF, NT-3, and NT-4 and their Trk receptors. NT-3 and its receptor TrkC showed the highest induction. NT-3 was localized to repairing cells, whereas TrkC was observed in stromal cells, osteoblasts, and blood vessel cells at the injury site. Moreover, systemic NT-3 immunoneutralization reduced bone volume at injury sites and also reduced vascularization at the injured growth plate, whereas recombinant NT-3 treatment promoted bony repair with elevated levels of mRNA for osteogenic markers and bone morphogenetic protein (BMP-2) and increased vascularization and mRNA for vascular endothelial growth factor (VEGF) and endothelial cell marker CD31 at the injured growth plate. When examined in vitro, NT-3 promoted osteogenesis in rat bone marrow stromal cells, induced Erk1/2 and Akt phosphorylation, and enhanced expression of BMPs (particularly BMP-2) and VEGF in the mineralizing cells. It also induced CD31 and VEGF mRNA in rat primary endothelial cell culture. BMP activity appears critical for NT-3 osteogenic effect in vitro because it can be almost completely abrogated by co-addition of the BMP inhibitor noggin. Consistent with its angiogenic effect in vivo, NT-3 promoted angiogenesis in metatarsal bone explants, an effect abolished by co-treatment with anti-VEGF. This study suggests that NT-3 may be an osteogenic and angiogenic factor upstream of BMP-2 and VEGF in bony repair, and further studies are required to investigate whether NT-3 may be a potential target for preventing growth plate faulty bony repair or for promoting bone fracture healing. © 2016

  14. Tectonics and geology of spreading ridge subduction at the Chile Triple Junction: a synthesis of results from Leg 141 of the Ocean Drilling Program

    USGS Publications Warehouse

    Behrmann, J.H.; Lewis, S.D.; Cande, S.C.

    1994-01-01

    An active oceanic spreading ridge is being subducted beneath the South American continent at the Chile Triple Junction. This process has played a major part in the evolution of most of the continental margins that border the Pacific Ocean basin. A combination of high resolution swath bathymetric maps, seismic reflection profiles and drillhole and core data from five sites drilled during Ocean Drilling Program (ODP) Leg 141 provide important data that define the tectonic, structural and stratigraphic effects of this modern example of spreading ridge subduction. A change from subduction accretion to subduction erosion occurs along-strike of the South American forearc. This change is prominently expressed by normal faulting, forearc subsidence, oversteepening of topographic slopes and intensive sedimentary mass wasting, overprinted on older signatures of sediment accretion, overthrusting and uplift processes in the forearc. Data from drill sites north of the triple junction (Sites 859-861) show that after an important phase of forearc building in the early to late Pliocene, subduction accretion had ceased in the late Pliocene. Since that time sediment on the downgoing oceanic Nazca plate has been subducted. Site 863 was drilled into the forearc in the immediate vicinity of the triple junction above the subducted spreading ridge axis. Here, thick and intensely folded and faulted trench slope sediments of Pleistocene age are currently involved in the frontal deformation of the forearc. Early faults with thrust and reverse kinematics are overprinted by later normal faults. The Chile Triple Junction is also the site of apparent ophiolite emplacement into the South American forearc. Drilling at Site 862 on the Taitao Ridge revealed an offshore volcanic sequence of Plio-Pleistocene age associated with the Taitao Fracture Zone, adjacent to exposures of the Pliocene-aged Taitao ophiolite onshore. Despite the large-scale loss of material from the forearc at the triple junction

  15. Instruments and MethodsAutonomous underwater vehicles (AUVs) and investigations of the ice-ocean interface in Antarctic and Arctic waters

    NASA Astrophysics Data System (ADS)

    Dowdeswell, J. A.; Evans, J.; Mugford, R.; Griffiths, G.; McPhail, S.; Millard, N.; Stevenson, P.; Brandon, M. A.; Banks, C.; Heywood, K. J.; Price, M. R.; Dodd, P. A.; Jenkins, A.; Nicholls, K. W.; Hayes, D.; Abrahamsen, E. P.; Tyler, P.; Bett, B.; Jones, D.; Wadhams, P.; Wilkinson, J. P.; Stansfield, K.; Ackley, S.

    Limitations of access have long restricted exploration and investigation of the cavities beneath ice shelves to a small number of drillholes. Studies of sea-ice underwater morphology are limited largely to scientific utilization of submarines. Remotely operated vehicles, tethered to a mother ship by umbilical cable, have been deployed to investigate tidewater-glacier and ice-shelf margins, but their range is often restricted. The development of free-flying autonomous underwater vehicles (AUVs) with ranges of tens to hundreds of kilometres enables extensive missions to take place beneath sea ice and floating ice shelves. Autosub2 is a 3600 kg, 6.7 m long AUV, with a 1600 m operating depth and range of 400 km, based on the earlier Autosub1 which had a 500m depth limit. A single direct-drive d.c. motor and five-bladed propeller produce speeds of 1-2 ms-1. Rear-mounted rudder and stern-plane control yaw, pitch and depth. The vehicle has three sections. The front and rear sections are free-flooding, built around aluminium extrusion space-frames covered with glass-fibre reinforced plastic panels. The central section has a set of carbon-fibre reinforced plastic pressure vessels. Four tubes contain batteries powering the vehicle. The other three house vehicle-control systems and sensors. The rear section houses subsystems for navigation, control actuation and propulsion and scientific sensors (e.g. digital camera, upward-looking 300 kHz acoustic Doppler current profiler, 200 kHz multibeam receiver). The front section contains forward-looking collision sensor, emergency abort, the homing systems, Argos satellite data and location transmitters and flashing lights for relocation as well as science sensors (e.g. twin conductivity-temperature-depth instruments, multibeam transmitter, sub-bottom profiler, AquaLab water sampler). Payload restrictions mean that a subset of scientific instruments is actually in place on any given dive. The scientific instruments carried on Autosub

  16. Sedimentary basins reconnaissance using the magnetic Tilt-Depth method

    NASA Astrophysics Data System (ADS)

    Salem, Ahmed; Williams, Simon; Samson, Esuene; Fairhead, Derek; Ravat, Dhananjay; Blakely, Richard J.

    2010-09-01

    basement). The method is especially valuable as a reconnaissance tool in regions where drillhole or seismic information are either scarce, lacking, or ambiguous.

  17. Cataclasis and processes of particle size reduction

    NASA Astrophysics Data System (ADS)

    Blenkinsop, Tom G.

    1991-05-01

    The particle size distribution (P.S.D.) of fragmented geological materials is affected by the fragmentation process, initial size distribution, number of fracturing events, energy input, strain, and confining pressure. A summary of literature shows that the fractal dimension ( D) of the P.S.D. is increased by the number of fracturing events, energy input, strain, and confining pressure. Cenozoic cataclasis of granite, granodiorites, gneisses and arkose seen in cores from the Cajon Pass drillhole, southern California, produced P.S.D.s with values of D that varied from 1.88 to 3.08. Each rock type has a characteristic and more limited range of D. Areas of dilatant texture and mode I fracture-fillings have low average values (2.32 and 2.37) compared to an average value of 2.67 in shear fracture-fillings D has a good inverse correlation with average particle size. Data from fault rocks in the San Gabriel fault zone, southern California ( Anderson et al., 1983) have been reanalyzed to show that values of D are higher (2.10 5.52) and average particle size is lower than the Cajon Pass samples, but the ranges of values overlap, and the inverse correlation between D and average particle size is extended. Microstructural observations combined with these results suggest that three processes contributed to particle size reduction during cataclasis. The first process of feldspar alteration, which leads to low values of D, has not been previously recognized. The second process is probably constrained comminution ( Sammis et al., 1987), since the average D in shear fracture-fillings is close to the value of 2.58 predicted by this theory. A further stage of particle size reduction is demonstrated by an increase of D with cataclasis. This third process is selective fracture of larger particles, which may also operate during localization and the cataclastic flow-to-faulting transition as observed in experiments. A transition from constrained comminution to selective fracture of

  18. Provenance Investigations Using Magnetic Susceptibility of Pebble- to Cobble-Sized Clasts in the AND-2A Core, ANDRILL Southern McMurdo Sound Project, Antarctica

    NASA Astrophysics Data System (ADS)

    Strada, E.; Florindo, F.; Sandroni, S.; Talarico, F.; Acton, G.; Jovane, L.; Ohneiser, C.; Sagnotti, L.; Verosub, K. L.; Wilson, G. S.; Science Team

    2008-12-01

    (Blue Glacier area), corroborating the inferences of the petrography-based provenance studies. These preliminary results point out the importance of mineral magnetic measurements in providing additional constrains and a useful data set for on-going provenance investigations of Cenozoic sediments recovered by recent ANDRILL drillholes in the McMurdo Sound area.

  19. The potential of stalagmites from the Patagonian Andes as sub-annually-resolved paleoclimate records

    NASA Astrophysics Data System (ADS)

    Kilian, Rolf; Schimpf, Daniel; Mangini, Augusto; Kronz, Andreas; Wörner, Gerhard; Simon, Klaus; Spötl, Christoph; Arz, Helge

    2010-05-01

    Stalagmites of the superhumid southern Andes are occasionally formed in small non-carst caves in a metamorphic and/or granitoid basement. They originate from coastal erosion in fracture zones during periods of higher sea levels. These small and relatively open caves are equilibrated with outside temperatures. Their drip rates reflect regional precipitation related to westerly wind intensities. To evaluate the reproducibility of proxies of different stalagmites we have investigated three U/Th-dated stalagmites (each one with 14-16 ages) from a single cave which grew simultaneously during the last 5 Ka. The host rocks provide a large variety of fine-grained siliciclastic minerals which are deposited on the stalagmite. Thin sections, scanning electron microscope, electron microprobe, and cave monitoring show that up to 3 wt% of siliciclastic minerals was accumulated successively on top of the stalagmites, depending on the individual drip rates above a certain threshold level. The amount of detritus was determined by the contents of detrital elements like Y and HREE, which were measured by ICP-MS (LAM-ICP-MS) from drill-holes (1-1.5 mm diameter) and laser ablation (5-10 μm steps). The LAM-ICP-MS pattern of e.g. Y and Al show a monthly resolution with clear seasonal cycles for the last 5 Kyrs. The presumable annual cycles match well into the time span in-between single Th/U ages. The seasonality results from two times higher drip rates in southern hemisphere summer (stronger westerlies) compared to winter. The time series show annual as well as typical sun-spot-related cyclicities (~11, 90, 210 years). Since these proxies are only sensitive to precipitation (and westerly changes) we suggest that the westerly intensities are controlled indirectly by changes in the sun's activity. Typically acid soil water with pH values of 3-5 leach several elements (U, Sr, Fe, Mg etc.) from the surrounding rocks, leading to high Mg/Ca ratios in the stalagmite during less humid periods

  20. Rift inheritance in orogenes: a case study from the Western Pyrenees

    NASA Astrophysics Data System (ADS)

    Masini, E.; Manatschal, G.; Tugend, J.; Kusznir, N. J.; Flament, J.

    2012-12-01

    In plate tectonics, there is a general assumption that rifted margins represent most of the former material accreted into collisional orogenic prisms. In this regard, the former architecture, structures and composition of rifted margins, i.e. the pre-orogenic inheritances, play undoubtedly a major role during tectonic inversion. Studies have shown that rifted margins are more complex than a succession of tilted blocks. Indeed, the discovery of hyper-extended domains, where low-angle detachments replace high-angle normal faults and mantle material is exhumed to the seafloor implies a revision of the margin's template used in orogenic models. Because of overprint, the role of rift inheritance in orogenes remains often underestimated. The Pyrenees, located along the Iberian-European plate boundary, can be considered as one of the best places to study the reactivation of hyper-extended rifts. In this orogen, the Late Cretaceous and Tertiary convergence overprints a Latest Jurassic to Lower Cretaceous intracontinental rift linked with the opening of the North Atlantic. There, Albian hyper-extended rift basins developed where deep crustal and mantle rocks were exhumed along low-angle detachments to the seafloor. In this work we discuss the example of the Mauléon-Arzacq domain, which escaped from the most pervasive deformation because of its specific location between the western termination of the chain and the Bay of Biscay oceanic domain. Combining field study with subsurface geophysical and drillhole data, we show that the overall rift domain is asymmetric. The northern European upper plate is on the hangingwall of low-angle detachment systems affecting the southern Iberian Lower plate. The upper plate records depth-dependent crustal thinning and the development of a syn-rift sag basin. In contrast, the lower plate resulted from the hyper-extension of Iberian continental crust accommodated at the surface by two diachronous top-basement detachment systems. The first

  1. Environmental Challenges Related to the Acquisition of the Trans Carpathian Wide Angle Reflection and Refraction Line

    NASA Astrophysics Data System (ADS)

    Dragut, Dorina-Alina; Schultz, Gehrig; Mocanu, Victor; Stephenson, Randell; Janik, Tomasz; Starostenko, Vitaly

    2015-04-01

    Complex structures like the Carpathian Orogen and its neighbouring platforms and related inter-orogenic basin system can be understood only by complex integration of complementary investigative tools. Most of regional geoscientific investigations in Romania have targeted the very intricate, high intermediate-depth seismicity, clustered Carpathian Bend Zone: Vrancea. Despite huge geological and geophysical efforts, the area remains a matter of robust debate, at least from the point of view of geodynamic driving mechanisms. However, other areas outside Vrancea remained somehow "orphaned". However, a large wide angle refraction and reflection (WARR) survey was carried out in the summer of 2014 by a large international partnership in order to study the transition from the East European Platform to the northern part of the Romanian Eastern Carpathians, Transylvanian Basin and the Apuseni Mountains. The main scientific objectives of the WARR project relate to three main investigation domains: crustal architecture; affinity of crystalline basement and sedimentary basins architecture. The profile is about 700 km in total, in Ukraine and Romania. Recorders were placed at 1.75 - 2.0 km intervals along an alignment forming the Romanian segment. Recorders used were stand-alone DSS Cubes from the Helmholz Center of GFZ Potsdam and from the Institute of Geophysics of the Polish Academy of Sciences. The seismic sources were explosives ("Riogel" and "Riodet" by Maxam), with shotpoints spaced at 20 - 65 km with a total of 800 - 1200 kg explosives/site in clusters of drill-holes loaded with 50 kg explosive/hole, average depth of 25 m. Very complicated and legally-challenging environmental permitting requirements represented a real issue for successful implementation of the project. The main concern of local and central authorities related to potential pollution of sensitive components. Here, we present the strategy, actions and results concluded in order to reach the scientific and

  2. Bi-cycles petrographic association in middle part of East Pana PGE layers deposit

    NASA Astrophysics Data System (ADS)

    Asavin, Alex; Veksler, Ilya; Gorbunov, Artem

    2016-04-01

    The PGE mineralization in the East Pana layered gabbroic intrusion forms three discrete layers at different stratigraphic levels, which are traditionally labeled as zones A, B and C. In order to investigate possible relationships of mineralization with magmatic layering we sampled a 120 m long drill core section across zone B in the middle part of the intrusion and carried out detailed petrographic, mineralogical and geochemical studies of the samples. The ore zone is located in medial part of the of East's Pana deposite. The samples represent mainly from a layered sequence of gabbro and gabbro-norite. This zone is composed of interlayers of gabbroic sequences and gabbro-norite of various color, with different structures and different relationship of rock-forming minerals of Ol-Opx-Cpx-Pl. We studied one of key's drill-hole section of ore zone, in which is located two ore horizons. Fundamental feature layered intrusions are presence in cross-section cycles includes of stable petrographic association. In section of ore zone it is possible to select two most contrast petrographic types. Whole-rock analyses and petrographic observations reveal two units of modal layering comprising, from bottom to top, melanocratic gabbro grading upwards into mesocratic gabbro and gabbro-norite overlain by pegmatoidal, gabbroic rock with has sharp footwall and hanging wall contacts.There is also an olivine-bearing gabbro at the bottom of the lower unit. The ore horizons are located in same gabbro-norite type rock. The ore horizons are located in same gabbro-norite type part. The second upper ore zone located in more differential species types. There is the common trend of system evolution of well distinguished on triangle of Ol-Pl-Di, Ol-Pl-Q and other. However composition of the rocks in the two parts of our section show us similar, but independent trends. For example on diagram differentiation of rocks composition, with normative content of anorthite on the X axis, trends of

  3. Unravelling the deep fluid composition in the Taupo Volcanic Zone: insight into the magmatic-hydrothermal transition

    NASA Astrophysics Data System (ADS)

    Chambefort, I. S.; Lewis, B.; Boseley, C.; Begue, F.; Rae, A.

    2012-12-01

    The Ngatamariki Geothermal Field represents the only location in the Taupo Volcanic Zone where geothermal well drilling has intercepted intrusive rocks with a high temperature alteration halo. Thus it presents the perfect opportunity to study the magmatic-hydrothermal transition in the TVZ by characterising the nature of the deep magmatic fluids inferred to be linked to the geothermal heat source. In addition to the calc-alkaline Ngatamariki diorite (encountered in a 1985 drillhole; Wood, 1986), recent (2012) geothermal drilling encountered a quartz-phyric tonalite. After emplacement, these intrusions cooled, degassed, and produced a high temperature alteration halo, associated with intense quartz-illite/muscovite-pyrite alteration and pervasive quartz replacement of the overlying tuff-breccia. This alteration zone contains abundant high temperature quartz veins, similar to quartz veining stockwork characteristic of Porphyry Cu (±Au-Mo) systems. The recently encountered quartz-phyric tonalite contains common phenocrysts of quartz and pseudomorphs of plagioclase and minor ferromagnesian minerals (predominantly amphiboles) in a medium-grained, magnetite-bearing felsic groundmass. Quartz phenocrysts are generally rounded and embayed quartz eyes (≤1 cm diam.), or skeletal crystals. SEM-CL imaging was used to map the crystallisation history of the phenocrystic quartz in the tonalite and the quartz veins cross-cutting the diorite and overlying pyroclastic rocks. The quartz eyes show a complex growth history with zones of dissolution and recrystallisation. Skeletal quartz crystals also have complex zoning and are outlined by myrmekitic textures and/or dendritic overgrowths with the groundmass (granophyric textures). These features form in granites due to undercooling during shallow magmatic emplacement and are often associated with the exsolution of a volatile phase. Cathodoluminescence indicates that the edges of the quartz veins are lined by euhedral crystals

  4. Marine Isotope Stage 31 (1.07 Ma): An extreme interglacial in the Antarctic nearshore zone

    NASA Astrophysics Data System (ADS)

    Scherer, R.; Bohaty, S.; Harwood, D.; Roberts, A.; Taviani, M.

    2003-04-01

    As global end-member environments, the polar regions are the bellwether of global climate change. Climate modelling suggests that the polar regions are more profoundly impacted by global warming than low latitude regions, and recent warming documented in Arctic and Antarctic environments might be a result of this polar amplification process. It is not yet clear that the short-term records of recent warming represent the start of a long-term trend, however, stratigraphic records of past significant high latitude warm events likely reflect changes not limited to regional or local perturbation, but ones of global significance. Sea-ice plays an especially important role in climate, by influencing albedo, bottom water formation, biologic productivity, and heat, moisture and CO2 exchange between the ocean and the atmosphere. As such, proxy records such as diatom assemblages that indicate dramatic shifts in the presence, duration and extent of sea-ice are of special significance for climate model development and validation. The Cape Roberts Project, a stratigraphic drilling project in McMurdo Sound, Antarctica, recovered a two meters thick unconsolidated biogenic carbonate unit that was deposited on the flank of a deep water carbonate bank (CRP-1 drillhole, Lithologic Unit 3.1). The deposit is dated by diatom biostratigraphy, 87Sr/86Sr ratios in biogenic carbonate, and 40Ar/39Ar dating of an ice-rafted volcanic clast as between 1.13 and 0.79 Ma. A Reversed-to-Normal magnetic polarity transition is recognized within this stratigraphic unit, indicating the base of the Jaramillo (Chron C1r.1n), 1.07 Ma, which directly corresponds with Marine Isotope Stage 31 (MIS-31). Precise dating allows confident correlation of Unit 3.1 with any well-dated deep-sea record. Hemipelagic deposition includes abundant and diverse diatoms and calcareous plankton. The diatom floras are almost entirely pelagic and include many taxa that commonly occur only north of the polar front. Most

  5. Molybdenum Enrichment in the 3.2 Ga old Black Shales Recovered by Dixon Island-Cleaverville Drilling Project (DXCL-DP) in Northwestern Pilbara, Western Australia

    NASA Astrophysics Data System (ADS)

    Yamaguchi, K. E.; Kiyokawa, S.; Naraoka, H.; Ikehara, M.; Ito, T.; Suganuma, Y.; Sakamoto, R.; Hosoi, K.

    2010-12-01

    To obtain drillcores of Mesoarchean black shales with negligible modern weathering, we conducted continental drilling at Cleaverville coast in Pilbara, Western Australia. We recovered 3.2Ga sulfidic black shales of the Cleaverville Group from three drillholes (~200m in total), namely DX, CL1, and CL2. Information on the geology of the drilling site has been reported [1, 2]. Here we report the discovery of Mo enrichment in the 3.2Ga DXCL-DP black shales. We analyzed total chemical compositions of forty black shale samples from drillcore DX and fifty-six of those from CL1 and CL2. Molybdenum concentrations for DX samples ranged from 0.3 to 12.9ppm (Avg±1σ= 1.8±1.9ppm), and those for CL1 and CL2 (combined) ranged from 0.8 to 3.3ppm (Avg±1σ= 1.4±0.4ppm). The highest concentration of Mo occurs in Corg-rich sample, and is comparable to that of the contemporaneous Fig Tree Group in South Africa [3, 4]. The highest concentration of Mo in the DXCL-DP samples, ~13ppm, is lower than that found in the 2.5 Ga Mt. McRae Shale of the Hamersley Group, Western Australia (maximums are ~17ppm [5], and ~40ppm [6]). However, it is much higher, by thirteen times, than the average Mo concentration in the Phanerozoic shales (1ppm [7]). No significant enrichment of Mo was expected to occur in the before-GOE black shales if pO2 was as low as <10-6 PAL. Sulfur isotope analysis revealed, based on the variable δ34S values (-1.9 ~ +26.8‰), that bacterial sulfate reduction was so extensive in the 3.2Ga deep marine environments that sulfate utilization by sulfate-reducers was near completion [8]. Production of bacteriogenic sulfide would have enhanced fixation of dissolved Mo into sulfide minerals in sediments. This is rather a common process occurring in oxygen-depleted environments in the modern ocean ([9]). A combined enrichment of Mo, Corg, and S, together with high δ34S values for a sedimentary formation may be used as a strong evidence for operation of modern-day style sedimentary

  6. Some Recent Laboratory Measurements of Fault Zone Permeability

    NASA Astrophysics Data System (ADS)

    Morrow, C. A.; Lockner, D. A.

    2005-12-01

    The permeability of fault zone material is key to understanding fluid circulation and the role of pore fluids in earthquake generation and rupture dynamics. Permeability results of core samples from several scientific drillholes are presented, including new results from the SAFOD drillsite in California and the Chelungpu Fault in Taiwan. Permeability values at simulated in situ pressures range from 10-18 to 10-23 m2, a broad range reflecting differences in rock type, proximity to the fault (i.e., fault core, damage zone or country rock), and degree of interseismic healing and sealing. In addition to these natural characteristics, stress-relief and thermal cracking damage resulting from core retrieval will tend to increase the permeability of some of the deepest crystalline rock samples, although testing under in situ conditions can reduce these errors. Recently active fault rocks, with an interconnected network of fractures, tend toward the higher end of the permeability range, whereas fault rocks that have had time to heal through hydrothermal processes tend to have lower permeabilities. In addition, the permeability of borehole-derived core samples was found to be more sensitive to applied pressure than equivalent rocks obtained from surface outcrops because of weathering and other processes. Thus, permeability values of surface samples can not be adequately extrapolated to depth, highlighting the importance of deep drilling studies in determining in situ transport properties. Permeability studies also reveal the storage capacity of the fault rocks, an important parameter in the determination of excess fluid pressure potential. Storage capacity was found to be 10-10 to 10-11/Pa in the Chelungpu Fault cores. Typical down-hole permeability measurements are generally 1-2 orders of magnitude higher than laboratory-derived values because they sample joints and fractures in the damage zone that are larger in scale than the core samples. Consequently, most fluid flow at

  7. Black shale source rocks and oil generation in the Cambrian and Ordovician of the central Appalachian Basin, USA

    USGS Publications Warehouse

    Ryder, R.T.; Burruss, R.C.; Hatch, J.R.

    1998-01-01

    Nearly 600 million bbl of oil (MMBO) and 1 to 1.5 trillion ft3 (tcf) of gas have been produced from Cambrian and Ordovician reservoirs (carbonate and sandstone) in the Ohio part of the Appalachian basin and on adjoining arches in Ohio, Indiana, and Ontario, Canada. Most of the oil and gas is concentrated in the giant Lima-Indiana field on the Findlay and Kankakee arches and in small fields distributed along the Knox unconformity. Based on new geochemical analyses of oils, potential source rocks, bitumen extracts, and previously published geochemical data, we conclude that the oils in both groups of fields originated from Middle and Upper Ordovician blcak shale (Utica and Antes shales) in the Appalachian basin. Moroever, we suggest that approximately 300 MMBO and many trillions of cubic feet of gas in the Lower Silurian Clinton sands of eastern Ohio originated in the same source rocks. Oils from the Cambrian and Ordovician reservoirs have similar saturated hydrocarbon compositions, biomarker distributions, and carbon isotope signatures. Regional variations in the oils are attributed to differences in thermal maturation rather than to differences in source. Total organic carbon content, genetic potential, regional extent, and bitument extract geochemistry identify the balck shale of the Utica and Antes shales as the most plausible source of the oils. Other Cambrian and Ordovician shale and carbonate units, such as the Wells Creek formation, which rests on the Knox unconformity, and the Rome Formation and Conasauga Group in the Rome trough, are considered to be only local petroleum sources. Tmax, CAI, and pyrolysis yields from drill-hole cuttings and core indicate that the Utica Shale in eastern and central Ohio is mature with respect to oil generation. Burial, thermal, and hydrocarbon-generation history models suggest that much of the oil was generated from the Utica-Antes source in the late Paleozoic during the Alleghanian orogeny. A pervasive fracture network

  8. Cenozoic Tectonic Activity of the "Passive" North America Margin: Evidence for Cenozoic Activity on Mesozoic or Paleozoic Faults

    NASA Astrophysics Data System (ADS)

    Nedorub, O. I.; Knapp, C. C.

    2012-12-01

    The tectonic history of the Eastern North American Margin (ENAM) incorporates two cycles of continental assembly, multiple pulses of orogeny, rifting, and post-rift geodynamic evolution. This is reflected in the heterogeneous lithosphere of the ENAM which contains fault structures originated in Paleozoic to Mesozoic eras. The South Georgia Rift basin is probably the largest Mesozoic graben within its boundaries that is associated with the breakup of Pangea. It is composed of smaller sub-basins which appear to be bounded by high-angle normal faults, some of which may have been inverted in late Cretaceous and Cenozoic eras. Paleozoic structures may have been reactivated in Cenozoic time as well. The ENAM is characterized by N-NE maximum horizontal compressive stress direction. This maximum compressional stress field is sub-parallel to the strike of the Atlantic Coast province fault systems. Camden, Augusta, Allendale, and Pen Branch faults are four of the many such reactivated faults along the southern part of ENAM. These faults are now buried under the 0-400 m of loosely consolidated Cretaceous and Cenozoic age sediments and thus are either only partially mapped or currently not recognized. Some of the objectives of this study are to map the subsurface expression and geometry of these faults and to investigate the post Cretaceous deformation and possible causes of fault reactivation on a passive margin. This study employs an integrated geophysical approach to investigate the upper 200 m of identified locations of the above mentioned faults. 2-D high-resolution shallow seismic reflection and refraction methods, gravity surveys, GPR, 2-D electrical resistivity and well data are used for analyses and interpretation. Preliminary results suggest that Camden fault shows signs of Cenozoic reactivation through an approximately 30 m offset NW side up mainly along a steeply dipping fault zone in the basal contact of Coastal Plain sediments with the Carolina Piedmont. Drill-hole

  9. Fischer Assays of Oil-Shale Drill Cores and Rotary Cuttings from the Greater Green River Basin, Southwestern Wyoming

    USGS Publications Warehouse

    U.S. Geological Survey Oil Shale Assessment Team

    2008-01-01

    ,000 Fischer assays from 186 core holes and 240 rotary drill holes. Most of the oil yield data are from analyses performed by the former U.S. Bureau of Mines oil shale laboratory in Laramie, Wyoming, with some analyses made by private laboratories. Location data for 971 Wyoming oil-shale drill holes are listed in a spreadsheet that is included in the CD-ROM. These Wyoming Fischer assays and histograms are part of a much larger collection of oil-shale information, including geophysical and lithologic logs, water data, chemical and X-ray diffraction analyses on the Green River oil-shale deposits in Colorado, Utah, and Wyoming held by the U.S. Geological Survey. Because of an increased interest in oil shale, this CD-ROM containing Fischer assay data and oil-yield histograms for the Green River oil-shale deposits in southwestern Wyoming is being released to the public. Microsoft Excel spreadsheets included with Chapter 2 contain the Fischer assay data from the 426 holes and data on the company name and drill-hole name, and location. Histograms of the oil yields obtained from the Fischer assays are presented in both Grapher and PDF format. Fischer assay text data files are also included in the CD-ROM.

  10. Single-well tracer test sensitivity w. r. to hydrofrac and matrix parameters (case study for the Horstberg site in the N-German Sedimentary Basin)

    NASA Astrophysics Data System (ADS)

    Ghergut, I.; Behrens, H.; Holzbecher, E.; Jung, R.; Sauter, M.; Tischner, T.

    2012-04-01

    At the geothermal pilot site Horstberg in the N-German Sedimentary Basin, a complex field experiment program was conducted (2003-2007) by the Federal Institute for Geosciences and Natural Resources (BGR) together with the Leibniz Institute for Applied Geosciences (GGA), aimed at evaluating the performance of innovative technologies for heat extraction, for direct use, from a single geothermal well[1],[2]. The envisaged single-well operation schemes comprised inter-layer circulation through a large-area hydrofrac (whose successful creation could thus be demonstrated), and single-screen 'huff-puff' in suitable (stimulated) layers, seated in sandstone-claystone formations in 3-4 km depth, with temperatures exceeding 160 ° C. Relying on Horstberg tracer-test data, we analyze heat and solute tracer transport in three characteristic hydraulic settings: (A) single-screen, multi-layer push-pull, with spiking and sampling at lower well-screen in low-permeability sandstone layer ('Detfurth'), from which hydrofrac propagation (through several adjacent layers) was initiated; (B) single-screen, single-layer push-pull, with spiking and sampling at upper well-screen within a more permeable sandstone layer ('Solling'); (C) inter-layer vertical push through above-mentioned hydrofrac, with spiking at well-screen of A, and sampling at well-screen of B. Owing to drill-hole deviation, the hydraulically-induced frac will, in its vertical propagation, reach the upper sandstone layer in a certain horizontal distance X from the upper well-screen, whose value turns out to be the major controlling parameter for the system's thermal lifetime under operation scheme C (values of X below ~8 m leading to premature thermal breakthrough, with the minimum-target rate of fluid turnover; however, the injection pressure required for maintaining the target outflow rate will also increase with X, which renders scheme C uneconomical, or technically-infeasible, when X exceeds ~15 m). Tracer signals in C

  11. QUANTITATIVE METHODS FOR RESERVOIR CHARACTERIZATION AND IMPROVED RECOVERY: APPLICATION TO HEAVY OIL SANDS

    SciTech Connect

    James W. Castle; Fred J. Molz; Ronald W. Falta; Cynthia L. Dinwiddie; Scott E. Brame; Robert A. Bridges

    2002-10-30

    Improved prediction of interwell reservoir heterogeneity has the potential to increase productivity and to reduce recovery cost for California's heavy oil sands, which contain approximately 2.3 billion barrels of remaining reserves in the Temblor Formation and in other formations of the San Joaquin Valley. This investigation involves application of advanced analytical property-distribution methods conditioned to continuous outcrop control for improved reservoir characterization and simulation, particularly in heavy oil sands. The investigation was performed in collaboration with Chevron Production Company U.S.A. as an industrial partner, and incorporates data from the Temblor Formation in Chevron's West Coalinga Field. Observations of lateral variability and vertical sequences observed in Temblor Formation outcrops has led to a better understanding of reservoir geology in West Coalinga Field. Based on the characteristics of stratigraphic bounding surfaces in the outcrops, these surfaces were identified in the subsurface using cores and logs. The bounding surfaces were mapped and then used as reference horizons in the reservoir modeling. Facies groups and facies tracts were recognized from outcrops and cores of the Temblor Formation and were applied to defining the stratigraphic framework and facies architecture for building 3D geological models. The following facies tracts were recognized: incised valley, estuarine, tide- to wave-dominated shoreline, diatomite, and subtidal. A new minipermeameter probe, which has important advantages over previous methods of measuring outcrop permeability, was developed during this project. The device, which measures permeability at the distal end of a small drillhole, avoids surface weathering effects and provides a superior seal compared with previous methods for measuring outcrop permeability. The new probe was used successfully for obtaining a high-quality permeability data set from an outcrop in southern Utah. Results obtained

  12. Individual and combined effects of noise-like whole-body vibration and parathyroid hormone treatment on bone defect repair in ovariectomized mice.

    PubMed

    Matsumoto, Takeshi; Sato, Daisuke; Hashimoto, Yoshihiro

    2016-01-01

    The effectiveness of intermittent administration of parathyroid hormone and exposure to whole-body vibration on osteoporotic fracture healing has been previously investigated, but data on their concurrent use are lacking. Thus, we evaluated the effects of intermittent administration of parathyroid hormone, whole-body vibration, and their combination on bone repair in osteoporotic mice. Noise-like whole-body vibration with a broad frequency range was used instead of conventional sine-wave whole-body vibration at a specific frequency. Mice were ovariectomized at 9 weeks of age and subjected to drill-hole surgery in the right tibial diaphysis at 11 weeks. The animals were divided into four groups (n = 12 each): a control group, and groups treated with intermittent administration of parathyroid hormone, noise-like whole-body vibration, and both. From postoperative day 2, the groups treated with intermittent administration of parathyroid hormone and groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration were subcutaneously administered parathyroid hormone at a dose of 30 µg/kg/day. The groups treated with noise-like whole-body vibration and groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration were exposed to noise-like whole-body vibration at a root mean squared acceleration of 0.3g and frequency components of 45-100 Hz for 20 min/day. Following 18 days of interventions, the right tibiae were harvested, and the regenerated bone was analyzed by micro-computed tomography and nanoindentation testing. Compared with the control group, callus volume fraction was 40% higher in groups treated with intermittent administration of parathyroid hormone and 73% higher in groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration, and callus thickness was 35% wider in groups treated with both

  13. Erosion modelling and sedimentary balance in an early anthropised watershed during the Holocene

    NASA Astrophysics Data System (ADS)

    Vella, C.; Canut, V.; Parisot, J.-C.; Hermitte, D.; Fleury, J.; Dussouillez, P.; Pailles, C.; Duval, S.; Chausserie-Laprée, J.

    2009-04-01

    The ria of Renaïres, on the western part of a small calcareous range between Marseilles and the Rhône delta, is a natural, elongated and narrow calanque drained by only one stream, the Reraille. The reduced size of its catchment (12km2) enables the easy identification of the local influence of climate and sea level fluctuations on sedimentation rythms. The relative sea level rise was revealed by peat deposits located only 10 kilometers away from the ria (Vella et al., 2005). Human occupation is deduced by archaeological data on the catchment area (Martigues Local council Services) allowing comparison between diachronic maps of human occupation from the Neolitic to medieval period. As such, the watershed of Reraille is the perfect site to study influences of human impact on erosion and sedimentation during the Holocene. Sedimentation in the upper part of the basin has been completely excavated by recent archaelogical works prior to urban development. Sediment accumulation is totaly quantified and dated by archaelogical remains and radiocarbon datings. In the bottom of the basin, erosional products are measured from the sedimentation trapped in the highly protected ria. Quantification of the trapped sediment was determined from 10 geotechnical drillholes, 5 cored holes of 10m length, and an electrical resistivity survey comprising a longitudinal profile and 4 cross-sections. The data sets were integrated into a GIS program and allowed a 3D reconstruction of volumes trapped at the exit of the system. Although the outgoing volumes are considered as unimportant, an offshore seismic reflection survey is planned for september 2009 to establish baseline data. The results indicate that the sedimentation speed increased in the upper part of the catchment : sedimentation was low before VIth century BC, it increased for 1500 years and was highest during the modern period. This sedimentation dynamic could suggest an increased destabilization of hillsides particularly during

  14. Selection and stability of quantitative stratigraphic age models: Plio-Pleistocene glaciomarine sediments in the ANDRILL 1B drillcore, McMurdo Ice Shelf

    NASA Astrophysics Data System (ADS)

    Cody, Rosemary; Levy, Richard; Crampton, James; Naish, Timothy; Wilson, Gary; Harwood, David

    2012-10-01

    Interpretation of glacimarine sedimentary records from Antarctic shelf drillholes has been hampered by the ambiguous age of strata where erosional unconformities and coarse diamictite deposits truncate or omit the magnetostratigraphic and biostratigraphic units used for correlation. However, new quantitative biostratigraphic techniques enable the correlation of sparse, incomplete, and often reworked Plio-Pleistocene records of Ross Sea fossil diatom flora with the more extensively documented but potentially diachronous offshore history of species' first and last appearance datums (FADs and LADs). The approach uses comprehensive regional databases of fossil records and computer-automated search algorithms to find the multidimensional line of correlation (LOC) that best fits local observations, and to identify regionally isochronous biostratigraphic markers. Different model configurations can be used to produce LOCs that represent alternative working hypotheses regarding reworking and other sources of misfit in the biostratigraphic record, and that together provide an envelope of uncertainty for age interpretation. An integrated, quantitative chronostratigraphic model for the ANDRILL-1B drillcore was developed iteratively: an initial age model was constructed solely from preliminary on-ice observations of fossil diatom highest and lowest occurrences (HOs and LOs) and their correlation with a database of other local event records from 24 DVDP, CIROS, and IODP drillcore sections. The model was subsequently updated as off-ice work yielded additional biostratigraphic marker events and revised event horizons, Ar/Ar ages for volcanic material, better-constrained magnetostratigraphic interpretation, and refinements to computational/analytical methodology. The current quantitative biostratigraphic age model for the AND-1B hole integrates the local ranges of 29 diatom taxa, five dated volcanic samples, and independently constrained ages of five paleomagnetic reversals. During

  15. Oxygen isotope perspective on crustal evolution on early Earth: A record of Precambrian shales with emphasis on Paleoproterozoic glaciations and Great Oxygenation Event

    NASA Astrophysics Data System (ADS)

    Bindeman, I. N.; Bekker, A.; Zakharov, D. O.

    2016-03-01

    We present stable isotope and chemical data for 206 Precambrian bulk shale and tillite samples that were collected mostly from drillholes on all continents and span the age range from 0.5 to 3.5 Ga with a dense coverage for 2.5-2.2 Ga time interval when Earth experienced four Snowball Earth glaciations and the irreversible rise in atmospheric O2. We observe significant, downward shift of several ‰ and a smaller range of δ18 O values (7 to 9‰) in shales that are associated with the Paleoproterozoic and, potentially, Neoproterozoic glaciations. The Paleoproterozoic samples consist of more than 50% mica minerals and have equal or higher chemical index of alteration than overlying and underlying formations and thus underwent equal or greater degrees of chemical weathering. Their pervasively low δ18 O and δD (down to - 85 ‰) values provide strong evidence of alteration and diagenesis in contact with ultra-low δ18 O glacial meltwaters in lacustrine, deltaic or periglacial lake (sikussak-type) environments associated with the Paleoproterozoic glaciations. The δDsilicate values for the rest of Precambrian shales range from -75 to - 50 ‰ and are comparable to those for Phanerozoic and Archean shales. Likewise, these samples have similar ranges in δ13Corg values (-23 to - 33 ‰ PDB) and Corg content (0.0 to 10 wt%) to Phanerozoic shales. Precambrian shales have a large range of δ18 O values comparable to that of the Phanerozoic shales in each age group and formation, suggesting similar variability in the provenance and intensity of chemical weathering, except for the earliest 3.3-3.5 Ga Archean shales, which have consistently lower δ18 O values. Moreover, Paleoproterozoic shales that bracket in age the Great Oxidation Event (GOE) overlap in δ18 O values. Absence of a step-wise increase in δ18 O and δD values suggests that despite the first-order change in the composition of the atmosphere, weathering cycle was not dramatically affected by the GOE at ∼2

  16. Groundwater Visualisation System (GVS): A software framework for integrated display and interrogation of conceptual hydrogeological models, data and time-series animation

    NASA Astrophysics Data System (ADS)

    Cox, Malcolm E.; James, Allan; Hawke, Amy; Raiber, Matthias

    2013-05-01

    Valley, and the Surat Basin, a large sedimentary basin of confined artesian aquifers. This latter example required more detail in the hydrostratigraphy, correlation of formations with drillholes and visualisation of simulation piezometric surfaces. Both alluvial system GVS models were developed during drought conditions to support government strategies to implement groundwater management. The Surat Basin model was industry sponsored research, for coal seam gas groundwater management and community information and consultation. The "virtual" groundwater systems in these 3D GVS models can be interactively interrogated by standard functions, plus production of 2D cross-sections, data selection from the 3D scene, rear end database and plot displays. A unique feature is that GVS allows investigation of time-series data across different display modes, both 2D and 3D. GVS has been used successfully as a tool to enhance community/stakeholder understanding and knowledge of groundwater systems and is of value for training and educational purposes. Projects completed confirm that GVS provides a powerful support to management and decision making, and as a tool for interpretation of groundwater system hydrological processes. A highly effective visualisation output is the production of short videos (e.g. 2-5 min) based on sequences of camera 'fly-throughs' and screen images. Further work involves developing support for multi-screen displays and touch-screen technologies, distributed rendering, gestural interaction systems. To highlight the visualisation and animation capability of the GVS software, links to related multimedia hosted online sites are included in the references.

  17. Sub-crop geologic map of pre-Tertiary rocks in the Yucca Flat and northern Frenchman Flat areas, Nevada Test Site, southern Nevada

    SciTech Connect

    Cole, J.C.; Harris, A.G.; Wahl, R.R.

    1997-10-02

    This map displays interpreted structural and stratigraphic relations among the Paleozoic and older rocks of the Nevada Test Site region beneath the Miocene volcanic rocks and younger alluvium in the Yucca Flat and northern Frenchman Flat basins. These interpretations are based on a comprehensive examination and review of data for more than 77 drillholes that penetrated part of the pre-Tertiary basement beneath these post-middle Miocene structural basins. Biostratigraphic data from conodont fossils were newly obtained for 31 of these holes, and a thorough review of all prior microfossil paleontologic data is incorporated in the analysis. Subsurface relationships are interpreted in light of a revised regional geologic framework synthesized from detailed geologic mapping in the ranges surrounding Yucca Flat, from comprehensive stratigraphic studies in the region, and from additional detailed field studies on and around the Nevada Test Site. All available data indicate the subsurface geology of Yucca Flat is considerably more complicated than previous interpretations have suggested. The western part of the basin, in particular, is underlain by relics of the eastward-vergent Belted Range thrust system that are folded back toward the west and thrust by local, west-vergent contractional structures of the CP thrust system. Field evidence from the ranges surrounding the north end of Yucca Flat indicate that two significant strike-slip faults track southward beneath the post-middle Miocene basin fill, but their subsurface traces cannot be closely defined from the available evidence. In contrast, the eastern part of the Yucca Flat basin is interpreted to be underlain by a fairly simple north-trending, broad syncline in the pre-Tertiary units. Far fewer data are available for the northern Frenchman Flat basin, but regional analysis indicates the pre-Tertiary structure there should also be relatively simple and not affected by thrusting. This new interpretation has implications

  18. After a century-Revised Paleogene coal stratigraphy, correlation, and deposition, Powder River Basin, Wyoming and Montana

    USGS Publications Warehouse

    Flores, Romeo M.; Spear, Brianne D.; Kinney, Scott A.; Purchase, Peter A.; Gallagher, Craig M.

    2010-01-01

    The stratigraphy, correlation, mapping, and depositional history of coal-bearing strata in the Paleogene Fort Union and Wasatch Formations in the Powder River Basin were mainly based on measurement and description of outcrops during the early 20th century. Subsequently, the quality and quantity of data improved with (1) exploration and development of oil, gas, and coal during the middle 20th century and (2) the onset of coalbed methane (CBM) development during the late 20th and early 21st centuries that resulted in the drilling of more than 26,000 closely spaced wells with accompanying geophysical logs. The closeness of the data control points, which average 0.5 mi (805 m) apart, made for better accuracy in the subsurface delineation and correlation of coal beds that greatly facilitated the construction of regional stratigraphic cross sections and the assessment of resources. The drillhole data show that coal beds previously mapped as merged coal zones, such as the Wyodak coal zone in the Wyoming part of the Powder River Basin, gradually thinned into several discontinuous beds and sequentially split into as many as 7 hierarchical orders westward and northward. The thinning and splitting of coal beds in these directions were accompanied by as much as a ten-fold increase in the thicknesses of sandstone-dominated intervals within the Wyodak coal zone. This probably resulted from thrust loading by the eastern front of the Bighorn uplift accompanied by vertical displacement along lineaments that caused subsidence of the western axial part of the Powder River Basin during Laramide deformation in Late Cretaceous and early Tertiary time. Accommodation space was thereby created for synsedimentary alluvial infilling that controlled thickening, thinning, splitting, pinching out, and areal distribution of coal beds. Equally important was differential subsidence between this main accommodation space and adjoining areas, which influenced the overlapping, for example, of the

  19. Mineralization by nanobacteria

    NASA Astrophysics Data System (ADS)

    Kajander, E. Olavi; Bjorklund, Michael; Ciftcioglu, Neva

    1998-07-01

    Nanobacteria are the smallest cell-walled bacteria, only recently discovered in human and cow blood and in commercial cell culture serum. In this study, we identified with energy-dispersive x-ray microanalysis and chemical analysis that all growth phases of nanobacteria produce biogenic apatite on their cell envelope. Fourier transform IR spectroscopy revealed the mineral as carbonate apatite. Previous models for stone formation have lead to a hypothesis that an elevated pH due to urease and/or alkaline phosphatase activity are important lithogenic factors. Our results indicate that carbonate apatite can be formed without these factors at pH 7.4 at physiological phosphate and calcium concentrations. Due to their specific macromolecules, nanobacteria can produce apatite very efficiency in media mimicking tissue fluids and glomerular filtrate and rapidly mineralizing most of available calcium and phosphate. This can be also monitored by (superscript 85)Sr incorporation and provides a unique model for in vitro studies on calcification. Recently, bacteria have been implicated in the formation of carbonate (hydroxy)fluorapatite in marine sediments. Apatite grains are found so commonly in sedimentary rocks that apatite is omitted in naming the stone. To prove that apatite and other minerals are formed by bacteria would implicate that the bacteria could be observed and their actions followed in stones. We have started to approach this in two ways. Firstly, by the use of sensitive methods for detecting specific bacterial components, like antigens, muramic acid and nucleic acids, that allow for detecting the presence of bacteria and, secondly, by follow-up of volatile bacterial metabolites observed by continuous monitoring with ion mobility spectrometry, IMCELL, working like an artificial, educatable smelling nose. The latter method might allow for remote real time detection of bacterial metabolism, a signature of life, in rocks via fractures of drillholes with or without

  20. Ground-water outflow from Chino Basin, Upper Santa Ana Valley, southern California

    USGS Publications Warehouse

    French, James J.

    1972-01-01

    Ground-water outflow from Chino basin was calculated ,by a direct method using the equation Q = PIA, in which Q is the quantity of ground-water outflow, P is the average coefficient of permeability of the sediments through which the flow occurs, I is the average hydraulic gradient, and A is the cross-sectional area of the sediments through which the flow occurs. The period selected for the calculation was 1930-66. Permeability of the water-bearing sediments was calculated from aquifer test data and from computations involving specific-capacity data from 200 wells in the outflow area. Permeability ranged from less than 100 to more than 5,000 gallons per day per square foot. The annual hydraulic gradient was derived from contour maps of average water levels in wells for each water year for the period 1930-66. The cross-sectional area used to calculate ground-water outflow from Chino basin extends southwestward from Pedley Hills to Puente Hills. The area of the outflow section is the saturated thickness of permeable materials measured along the line of section. Part of the lower boundary is the interface between the alluvium and the underlying basement complex, and part is a change in permeability within sedimentary rocks. Geological methods were combined with geophysical methods to determine the cross-sectional area of the water-bearing sediments. Gravity and seismic traverses, drill-hole logs, and data from a more than 600 drill holes, including eight test holes drilled as a part of this investigation, were used to delineate the size and the shape of the outflow area. For the period of calculation, 1930-66, the total area of the outflow section varied from about 16 to 22 million square feet. The fluctuation in total area is caused by changes in the altitude of the water table. Annual ground-water outflow from Chino basin calculated by the direct method for the period 1930-66 ranged from 38,000 acre-feet in the 1941 water year to 9,400 acre-feet in the 1966 water

  1. 2.8-Ma ash-flow caldera at Chegem River in the northern Caucasus Mountains (Russia), contemporaneous granites, and associated ore deposits

    USGS Publications Warehouse

    Lipman, P.W.; Bogatikov, O.A.; Tsvetkov, A.A.; Gazis, C.; Gurbanov, A.G.; Hon, K.; Koronovsky, N.V.; Kovalenko, V.I.; Marchev, P.

    1993-01-01

    Diverse latest Pliocene volcanic and plutonic rocks in the north-central Caucasus Mountains of southern Russia are newly interpreted as components of a large caldera system that erupted a compositionally zoned rhyolite-dacite ash-flow sheet at 2.83 ?? 0.02 Ma (sanidine and biotite 40Ar/39Ar). Despite its location within a cratonic collision zone, the Chegem system is structurally and petrologically similar to typical calderas of continental-margin volcanic arcs. Erosional remnants of the outflow Chegem Tuff sheet extend at least 50 km north from the source caldera in the upper Chegem River. These outflow remnants were previously interpreted by others as erupted from several local vents, but petrologic similarities indicate a common origin and correlation with thick intracaldera Chegem Tuff. The 11 ?? 15 km caldera and associated intrusions are superbly exposed over a vertical range of 2,300 m in deep canyons above treeline (elev. to 3,800 m). Densely welded intracaldera Chegem Tuff, previously described by others as a rhyolite lava plateau, forms a single cooling unit, is > 2 km thick, and contains large slide blocks from the caldera walls. Caldera subsidence was accommodated along several concentric ring fractures. No prevolcanic floor is exposed within the central core of the caldera. The caldera-filling tuff is overlain by andesitic lavas and cut by a 2.84 ?? 0.03-Ma porphyritic granodiorite intrusion that has a cooling age analytically indistinguishable from that of the tuffs. The Eldjurta Granite, a pluton exposed low in the next large canyon (Baksan River) 10 km to the northwest of the caldera, yields variable K-feldspar and biotite ages (2.8 to 1.0 Ma) through a 5-km vertical range in surface and drill-hole samples. These variable dates appear to record a prolonged complex cooling history within upper parts of another caldera-related pluton. Major W-Mo ore deposits at the Tirniauz mine are hosted in skarns and hornfels along the roof of the Eldjurta Granite

  2. Detailed lithologic log of the Dow Chemical #1 B.L. Garrigan Drill Hole, Mississippi County, Arkansas

    USGS Publications Warehouse

    Collins, Donley S.; Skipp, Gary L.

    1995-01-01

    arch and is an important source of core from the Reelfoot basin (Collins and others, 1992). Therefore, this drill hole is important for understanding structure and Paleozoic stratigraphy in a basin where stratigraphic and structural data are sparse. Rocks in the Garrigan were originally logged and described by J.R. Howe (personal communication to D.S. Collins, 1990) and published as a composite stratigraphic section along with the rock description for the Dow Chemical #1 Wilson drill hole (Howe, 1984). F.A. McKeown later relogged the rocks in the Garrigan and presented a generalized log in McKeown and others (1990). Swolfs (1991) presented another version of the Garrigan drill-hole geologic section (fig. 2). Aided by new biostratigraphic information, Taylor and others (1991) corrected major errors in the characterization and correlation of rocks in the Garrigan (fig. 2). Collins (1991) described the insoluble residues from the cuttings of the Garrigan, but could not correlate them with the insoluble resides from rocks of the carbonate platform west of the basin. However Taylor and others (1991), Collins and others (1992), and Collins and Bohm (1993) did correlate fossils from the Garrigan to other drill holes in the Reelfoot basin and adjacent areas. Using these correlated data, Collins and Bohm (1993) provided information on the structural relief across a part of the Reelfoot basin. Collins and others (1992) also interpreted the depositional setting for the Paleozoic rocks of the Garrigan. This report presents a detailed lithologic log of the Paleozoic rocks penetrated by the Garrigan that differs from the lithologic logs of previous workers (Howe, 1984; McKeown and others, 1990; see also Dart, 1992, p. 18-19). The lithologic descriptions of the Garrigan are derived from observations of well cuttings and core. Cored intervals used were 11,426-11,402 ft, 10,229-10,200 ft, and 8,002-7,979 ft. These intervals were the only intervals cored during the Garrigan drill

  3. Geologic and hydrologic considerations for various concepts of high-level radioactive waste disposal in conterminous United States

    USGS Publications Warehouse

    Ekren, E.B.; Dinwiddie, G.A.; Mytton, J.W.; Thordarson, William; Weir, J.E., Jr.; Hinrichs, E.N.; Schroder, L.J.

    1974-01-01

    rise is very low, (3) where a possible return of glacial or pluvial climate will not cause potentially hazardous changes in surface- or ground-water regimens, and (4) where danger of exhumation by erosion is nil. The geographic location for an optimum site is one that is far removed from major drainages, lakes, and oceans, where population density is low, and where the topographic relief is gentle in order to avoid steep surface-water drainage gradients that would allow rapid distribution of contaminants in case of accident. The most suitable medium for the unproven deep drill-hole, matrix-holes, and exploded-cavity methods appears to be crystalline rocks, either intrusive igneous or metamorphic because of their potentially low permeabilities and high mechanical strengths. Salt (either in thick beds or stable domes), tuff, and possibly shale appear to be suitable for mined chambers and cavities with separate manmade structures. Salt appears to be suitable because of its very low permeability, high thermal conductivity, and natural plasticity. Tuff and shale appear suitable because of their very low permeabilities and high ion-exchange capacities. Sedimentary rocks other than shale and volcanic rocks, exclusive of tuff, are considered to be generally unsuitable for waste emplacement because of their potentially high permeabilities. Areas that appear to satisfy most geohydrologic requirements for the deep drill hole and the matrix holes include principally (1) the stable continental interior where the sedimentary cover is thin or absent, (2) the shield area of the North-Central States, and (3) the metamorphic belt of Eastern United States--primarily the Piedmont. These areas are possibly suitable also for the exploded cavity and the mined chamber because the possibility of finding rock with very- permeability at depths from 1,000? feet (305? m) to 20,000 feet (6,100 m) appears to be high. The Basin and Range province of Western United States, particula

  4. Tectonics of the Kola collision suture and adjacent Archaean and Early Proterozoic terrains in the northeastern region of the Baltic Shield

    NASA Astrophysics Data System (ADS)

    Berthelsen, Asger; Marker, Mogens

    1986-06-01

    As preparation for the deep-seismic and other geophysical experiments along the Polar Profile, which transects the Granulite belt and the Kola collision suture, structural field work has been performed in northernmost Finland and Norway, and published geological information including data from the neighbouring Soviet territory of the Kola Peninsula, have been compiled and reinterpreted. Based on these studies and a classification according to crustal and structural ages, the northeastern region of the Baltic Shield is divided into six major tectonic units. These units are separated and outlined by important low-angle, ductile shear or thrust zones of Late Archaean to Early Proterozoic age. The lateral extension of these units into Soviet territory and their involvement in large-scale crustal deformation structures, are described. Using the "view down the plunge" method, a generalised tectonic cross-section that predicts the crustal structures along the Polar Profile is compiled, and the structures around the Kola deep drill-hole are reinterpreted. The Kola suture belt, through parts of which the Kola deep bore-hole has been drilled, is considered to represent a ca. 1900 Ma old arc-continent and continent-continent collision suture. It divides the northeastern Shield region into two major crustal compartments: a Northern compartment (comprising the Murmansk and Sörvaranger units) and a Southern compartment (including the Inari unit, the Granulite belt and the Tanaelv belt, as well as the more southernly situated South Lapland-Karelia "craton" of the Karelian province of the Svecokarelian fold belt). The Kola suture belt is outlined by a 2-40 km wide and ca. 500 km long crustal belt composed of (1) Early Proterozoic (ca. 2400-2000 Ma old) metavolcanic and metasedimentary sequences which originally formed part of the attenuated margin of the Northern Archaean compartment, and (2) the remains of a ca. 2000-1900 Ma old, predominantly andesitic island-arc terrain. This