WorldWideScience

Sample records for bedrock refractive-flow cells

  1. Bedrock refractive-flow cells: A passive treatment analog to funnel-and-gate

    Energy Technology Data Exchange (ETDEWEB)

    Dick, V.; Edwards, D. [Haley & Aldrich, Inc., New York, NY (United States)

    1997-12-31

    Funnel-and-gate technology provides a mechanism to passively treat groundwater contaminant plumes, but depends on placement of a sufficient barrier ({open_quotes}funnel{close_quotes}) in the plume flow path to channel the plume to a pass-through treatment zone ({open_quotes}gate{close_quotes}). Conventional barrier technologies limit funnel-and-gate deployment to unconsolidated overburden applications. A method has been developed which allows similar passive treatment to be applied to bedrock plumes. Rather than use barriers as the funnel, the method uses engineered bedrock zones, installed via precision blasting or other means, to refract groundwater flow along a preferred path to treatment (gate). The method requires orienting the refractive cell based on the Tangent Law and extending refractive cell limbs down gradient of the gate to disperse head and control flow. A typical Refractive-Flow cell may be{open_quotes}Y{close_quotes}shaped, with each limb 3-10 ft [1-3 m] wide and several tens to a few hundred feet [10 - 100 m] in length. Treatment takes place at the center of the X. MODFLOW modeling has been used to successfully simulate desired flow. Engineered blasting has been used at full scale application to create bedrock rubble zones for active collection/flow control for several years. The method provides a previously unavailable method to passively treat contaminated groundwater in bedrock at low cost.

  2. Iowa Bedrock Geology

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — The bedrock geologic map portrays the current interpretation of the distribution of various bedrock stratigraphic units present at the bedrock surface. The bedrock...

  3. Iowa Bedrock Topography

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — The Map of the Elevation of the Bedrock Surface in Iowa was compiled using all available data, principally information from GEOSAM, supplemented with well and boring...

  4. Iowa Bedrock Surface Elevation

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This Digital Elevation Model (DEM) of the bedrock surface elevation in Iowa was compiled using all available data, principally information from GEOSAM, supplemented...

  5. Ogallala Bedrock Data Enhancement

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set provides an enhanced estimate of the bedrock elevation of the Ogallala Aquifer in Kansas based on lithologic logs from a variety of sources. The data...

  6. Flow in bedrock canyons.

    Science.gov (United States)

    Venditti, Jeremy G; Rennie, Colin D; Bomhof, James; Bradley, Ryan W; Little, Malcolm; Church, Michael

    2014-09-25

    Bedrock erosion in rivers sets the pace of landscape evolution, influences the evolution of orogens and determines the size, shape and relief of mountains. A variety of models link fluid flow and sediment transport processes to bedrock incision in canyons. The model components that represent sediment transport processes are increasingly well developed. In contrast, the model components being used to represent fluid flow are largely untested because there are no observations of the flow structure in bedrock canyons. Here we present a 524-kilometre, continuous centreline, acoustic Doppler current profiler survey of the Fraser Canyon in western Canada, which includes 42 individual bedrock canyons. Our observations of three-dimensional flow structure reveal that, as water enters the canyons, a high-velocity core follows the bed surface, causing a velocity inversion (high velocities near the bed and low velocities at the surface). The plunging water then upwells along the canyon walls, resulting in counter-rotating, along-stream coherent flow structures that diverge near the bed. The resulting flow structure promotes deep scour in the bedrock channel floor and undercutting of the canyon walls. This provides a mechanism for channel widening and ensures that the base of the walls is swept clear of the debris that is often deposited there, keeping the walls nearly vertical. These observations reveal that the flow structure in bedrock canyons is more complex than assumed in the models presently used. Fluid flow models that capture the essence of the three-dimensional flow field, using simple phenomenological rules that are computationally tractable, are required to capture the dynamic coupling between flow, bedrock erosion and solid-Earth dynamics.

  7. Bedrock geologic map of Vermont

    Science.gov (United States)

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

    2011-01-01

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

  8. Bedrock Geologic Map of Woodstock, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG06-4 Thompson, P. J., 2006, Bedrock Geologic Map of Woodstock, Vermont: VGS Open-File Report VG06-4, scale 1:24,000. The bedrock geologic map...

  9. Bedrock Hydrogeology - Site investigation SFR

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Johan [Geosigma AB, Stockholm (Sweden); Bockgaard, Niclas [Golder Assoes AB, Stockholm (Sweden); Follin, Sven [SF GeoLogic AB, Taeby (Sweden)

    2012-06-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) has conducted site investigations for a planned extension of the existing final repository for short-lived radioactive waste (SFR). This report presents an integrated analysis and interpretation of the historic data from the existing SFR (1980 - 1986), as well as, from the recent investigations for the planned extension of SFR (2008 - 2009). The primary objective is to establish a conceptual hydrogeological model of the bedrock for safety assessment and design analyses. Analyses and interpretations of all (old and new) hydraulic data are analysed with regard to the recently developed geological deformation zone model of the SFR model domain (Curtis et al. 2011). The methodology used by Curtis et al. (2011) has focussed on magnetic anomalies and deformation zone intercepts with ground surface greater than 300 m. In the hydrogeological modelling, however, it has been considered important to also explore the occurrence and characteristics of shallow horizontal to sub-horizontal structures (sheet joints) inside the SFR model domain. Such structures are of considerable importance for the hydrogeology in the uppermost c. 150 m of bedrock in SDM-Site Forsmark; hence the term Shallow Bedrock Aquifer was used to emphasise their hydraulic significance. In this study, the acronym SBA-structure is used for horizontal structures identified in the hydrogeological modelling. In addition to the predominantly steeply dipping geological deformation zones, eight so-called SBA-structures are modelled deterministically in the hydrogeological model. The SBA-structures are envisaged as hydraulically heterogeneous and composed of clusters of minor gently dipping to horizontal fractures rather than extensive single features. A type of structures that is partly included in the definition of the SBA-structures is the Unresolved Possible Deformations Zone (Unresolved PDZ) intercepts identified by Curtis et al. (2011). The Unresolved

  10. SFR site investigation. Bedrock Hydrogeochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Ann-Chatrin [Geosigma AB, Uppsala (Sweden); Tullborg, Eva-Lena [Terralogica AB, Graabo (Sweden); Smellie, John [Conterra AB, Uppsala (Sweden); Gimeno, Maria J.; Gomez, Javier B.; Auque, Luis F. [Univ. of Zaragoza, Zaragoza (Spain); Sandstroem, Bjoern [WSP Sverige AB, Goeteborg (Sweden); Pedersen, Karsten [Micans AB, Moelnlycke (Sweden)

    2011-11-15

    There are plans that the final repository for low and intermediate level radioactive waste, SFR, located about 150 km north of Stockholm, will be extended. Geoscientific studies to define and characterise a suitable bedrock volume for the extended repository have been carried out from 2007 to 2011, and have included the drilling and evaluation of seven new core drilled and four percussion boreholes. These new data, together with existing data extending back to 1985, have been interpreted and modelled in order to provide the necessary information for safety assessment and repository design. This report presents the final hydrogeochemical site description for the SFR site, and will constitute a background report for the integrated site description (the SFR Site Descriptive Model version 1.0) together with corresponding reports from the geological and hydrogeological disciplines. Most of the hydrogeochemical data from the field investigations consist of major ions and isotopes together with sporadic gas, microbe and measured redox data. Despite the close proximity of the Forsmark site, few data from this source are of relevance because of the shallow nature of the SFR site, the fact that SFR is located beneath the Baltic Sea and also the drawdown/upconing impacts of its construction on the hydrogeochemistry. This artificially imposed dynamic flow system is naturally more prevalent along major deformation fracture zones of higher transmissivity, whilst lower transmissive fractures together with the less transmissive bedrock masses between major deformation zones, still retain some evidence of the natural groundwater mixing patterns established prior to the SFR construction. The groundwaters in the SFR dataset cover a depth down to -250 m.a.s.l. with single sampling locations at -300 and -400 m.a.s.l. and represent a relatively limited salinity range (1,500 to 5,500 mg/L chloride). However, the {delta}{sup 18}O values show a wide variation (-15.5 to -7.5 per mille V

  11. Depth to Bedrock: Isopach of Unconsolidated Materials

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This vector dataset gives the approximate depth to bedrock (in feet) from Iowa's current land surface. This 50 foot isopach data was derived from the Digital...

  12. SFR site investigation. Bedrock Hydrogeochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Ann-Chatrin [Geosigma AB, Uppsala (Sweden); Tullborg, Eva-Lena [Terralogica AB, Graabo (Sweden); Smellie, John [Conterra AB, Uppsala (Sweden); Gimeno, Maria J.; Gomez, Javier B.; Auque, Luis F. [Univ. of Zaragoza, Zaragoza (Spain); Sandstroem, Bjoern [WSP Sverige AB, Goeteborg (Sweden); Pedersen, Karsten [Micans AB, Moelnlycke (Sweden)

    2011-11-15

    There are plans that the final repository for low and intermediate level radioactive waste, SFR, located about 150 km north of Stockholm, will be extended. Geoscientific studies to define and characterise a suitable bedrock volume for the extended repository have been carried out from 2007 to 2011, and have included the drilling and evaluation of seven new core drilled and four percussion boreholes. These new data, together with existing data extending back to 1985, have been interpreted and modelled in order to provide the necessary information for safety assessment and repository design. This report presents the final hydrogeochemical site description for the SFR site, and will constitute a background report for the integrated site description (the SFR Site Descriptive Model version 1.0) together with corresponding reports from the geological and hydrogeological disciplines. Most of the hydrogeochemical data from the field investigations consist of major ions and isotopes together with sporadic gas, microbe and measured redox data. Despite the close proximity of the Forsmark site, few data from this source are of relevance because of the shallow nature of the SFR site, the fact that SFR is located beneath the Baltic Sea and also the drawdown/upconing impacts of its construction on the hydrogeochemistry. This artificially imposed dynamic flow system is naturally more prevalent along major deformation fracture zones of higher transmissivity, whilst lower transmissive fractures together with the less transmissive bedrock masses between major deformation zones, still retain some evidence of the natural groundwater mixing patterns established prior to the SFR construction. The groundwaters in the SFR dataset cover a depth down to -250 m.a.s.l. with single sampling locations at -300 and -400 m.a.s.l. and represent a relatively limited salinity range (1,500 to 5,500 mg/L chloride). However, the {delta}{sup 18}O values show a wide variation (-15.5 to -7.5 per mille V

  13. Flow Structure in a Bedrock Canyon (Invited)

    Science.gov (United States)

    Venditti, J. G.; Rennie, C. D.; Church, M. A.; Bomhof, J.; Lin, M.

    2013-12-01

    Bedrock canyon incision is widely recognized as setting the pace of landscape evolution. A variety of models link flow and sediment transport processes to the bedrock canyon incision rate. The model components that represent sediment transport processes are quite well developed in some models. In contrast, the model components that represent fluid flow remain rudimentary. Part of the reason is that there have been relatively few observations of flow structure in a bedrock canyon. Here, we present observations of flow obtained using an array of three acoustic Doppler current profilers during a 524 km long continuous centerline traverse of the Fraser River, British Columbia, Canada as it passes through a series of bedrock canyons. Through this portion of the river, the channel alternates between gravel-bedded reaches that are deeply incised into semi-consolidated glacial deposits and solid bedrock-bound reaches. We present observations of flow through 41 bedrock bound reaches of the river, derived from our centerline traverses and more detailed three-dimensional mapping of the flow structure in 2 canyons. Our observations suggest that flow in the most well-defined canyons (deep, laterally constrained, completely bedrock bound) is far more complex than that in a simple prismatic channel. As flow enters the canyon, a high velocity core plunges from the surface to the bed, causing a velocity inversion (high velocities at the bed and low velocities at the surface). This plunging flow then upwells along the canyon wall, resulting in a three-dimensional flow with counter-rotating, along-stream eddies that diverge near the bed. We observe centerline ridges along the canyon floors that result from the divergence and large-scale surface boils caused by the upwelling. This flow structure causes deep scour in the bedrock channel floor, and ensures the base of the canyon walls are swept of debris that otherwise may be deposited due to lower shear stresses abutting the walls. The

  14. Structure of Flow in a Bedrock Canyon

    Science.gov (United States)

    Venditti, J. G.; Rennie, C. D.; Church, M. A.; Bomhof, J.; Lin, M.

    2012-12-01

    Bedrock canyon incision is widely recognized as setting the pace of landscape evolution. A variety of models link flow and sediment transport processes to the bedrock canyon incision rate. The model components that represent sediment transport processes are quite well developed in some models. In contrast, the model components that represent fluid flow remain rudimentary. Part of the reason is that there have been relatively few observations of flow structure in a bedrock canyon. Here, we present observations of flow obtained using an array of three acoustic Doppler current profilers during a 524 km long continuous centerline traverse of the Fraser River, British Columbia, Canada as it passes through a series of bedrock canyons. Through this portion of the river, the channel alternates between gravel-bedded reaches that are deeply incised into semi-consolidated glacial deposits and solid bedrock-bound reaches. We present observations of flow through 41 bedrock bound reaches of the river, derived from our centerline traverses and more detailed three-dimensional mapping of the flow structure in 2 canyons. Our observations suggest that flow in the most well-defined canyons (deep, laterally constrained, completely bedrock bound) is far more complex than that in a simple prismatic channel. As flow enters the canyon, a high velocity core plunges from the surface to the bed, causing a velocity inversion (high velocities at the bed and low velocities at the surface). This plunging flow then upwells along the canyon wall, resulting in a three-dimensional flow with counter-rotating, along-stream eddies that diverge near the bed. We observe centerline ridges along the canyon floors that result from the divergence and large-scale surface boils caused by the upwelling. This flow structure causes deep scour in the bedrock channel floor, and ensures the base of the canyon walls are swept of debris that otherwise may be deposited due to lower shear stresses abutting the walls. The

  15. GeologicBedrock100k Dikes

    Data.gov (United States)

    Vermont Center for Geographic Information — The bedrock geology was last mapped at a statewide scale 50 years ago at a scale of 1:250,000 (Doll and others, 1961). The 1961 map was compiled from 1:62,500-scale...

  16. Bedrock Geologic Map of the Hinesburg Quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from Thompson, P., Thompson, T.B., and Doolan, B., 2004, Bedrock Geology of the Hinesburg quadrangle, Vermont. The bedrock geologic map data at a scale...

  17. Characterization of a hydraulically induced bedrock fracture

    OpenAIRE

    2014-01-01

    Hydraulic fracturing is a controversial practice because of concerns about environmental impacts due to its widespread use in recovering unconventional petroleum and natural gas deposits. However, water-only hydraulic fracturing has been used safely and successfully for many years to increase the permeability of aquifers used for drinking and irrigation water supply. This process extends and widens existing bedrock fractures, allowing groundwater storage to increase. Researchers have studied ...

  18. Fractal Character of China Bedrock Coastline

    Institute of Scientific and Technical Information of China (English)

    朱晓华

    2004-01-01

    Fractal theory was applied to a preliminary discussion of the fractal character and formation mechanism of the coastline of the bedrock coast of China on the basis of GIS (Geographical Information System). Some significant conclusions were drawn:(1) The fractal dimensions of the coastline and linear structures of Liaodong Peninsula are 1.0093 and 1.0246 respectively, those of Shandong Peninsula are 1.019 and 1.021 respectively, etc.(2) The fractal dimensions of coastlines of Liaodong Peninsula, Shandong Peninsula, Zhejiang and Fujian-Guangdong tend to increase with the spatial change from north to south.(3)The regional linear structures(including faults)control the basic trends and fractal dimensions of coastlines as a whole in the regions of the bedrock coast of China:the more the controlling effect of linear structures, the smaller the fractal dimensions of coastlines.(4)The substantial constituents of coast and biologic function both play an important role in affecting the fractal dimensions of coastlines of Liaodong Peninsula, Shandong Peninsula, Zhejiang, Fujian-Guangdong and Taiwan Island.

  19. Localized bedrock aquifer distribution explains discharge from a headwater catchment

    Science.gov (United States)

    Kosugi, Ken'ichirou; Fujimoto, Masamitsu; Katsura, Shin'ya; Kato, Hiroyuki; Sando, Yoshiki; Mizuyama, Takahisa

    2011-07-01

    Understanding a discharge hydrograph is one of the leading interests in catchment hydrology. Recent research has provided credible information on the importance of bedrock groundwater on discharge hydrographs from headwater catchments. However, intensive monitoring of bedrock groundwater is rare in mountains with steep topography. Hence, how bedrock groundwater controls discharge from a steep headwater catchment is in dispute. In this study, we conducted long-term hydrological observations using densely located bedrock wells in a headwater catchment underlain by granitic bedrock. The catchment has steep topography affected by diastrophic activities. Results showed a fairly regionalized distribution of bedrock aquifers within a scale of tens of meters, consisting of upper, middle, and lower aquifers, instead of a gradual and continuous decline in water level from ridge to valley bottom. This was presumably attributable to the unique bedrock structure; fault lines developed in the watershed worked to form divides between the bedrock aquifers. Spatial expanse of each aquifer and the interaction among aquifers were key factors to explain gentle and considerable variations in the base flow discharge and triple-peak discharge responses of the observed hydrograph. A simple model was developed to simulate the discharge hydrograph, which computed each of the contributions from the soil mantle groundwater, from the lower aquifer, and from the middle aquifer to the discharge. The modeling results generally succeeded in reproducing the observed hydrograph. Thus, this study demonstrated that understanding regionalized bedrock aquifer distribution is pivotal for explaining discharge hydrograph from headwater catchments that have been affected by diastrophic activities.

  20. Geology, Bedrock - BEDROCK_TOPOGRAPHY_MM36_IN: Bedrock Topography Contours, Indiana (Indiana Geological Survey, 1:500,000, Line Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Bedrock topography was converted from the original published map, Indiana Geological Survey Miscellaneous Map 36. The contours define the elevation/topography of the...

  1. Forsmark site investigation. Bedrock geology - overview and excursion guide

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Michael B. (Geological Survey of Sweden, Uppsala (Sweden))

    2010-09-15

    Bearing in mind the significance of the bedrock data from the ground surface for the geological 3D modelling work, SKB decided to present excursion guides that serve in the demonstration of the bedrock geology at the ground surface in both the Forsmark (this guide) and Laxemar-Simpevarp areas. An excursion guide is also available for the Olkiluoto area in south-western Finland, which has been selected for the construction of a repository for the disposal of highly radioactive, spent nuclear fuel in Finland. The current excursion guide presents the bedrock geology and describes in detail the character of the bedrock at ten representative outcrops or outcrop areas at the ground surface in the site investigation area at Forsmark. All localities are located within or immediately adjacent to the proposed repository volume selected by SKB

  2. Oskarshamn site investigation. Bedrock geology - overview and excursion guide

    Energy Technology Data Exchange (ETDEWEB)

    Wahlgren, Carl-Henric (Geological Survey of Sweden, Uppsala (Sweden))

    2010-09-15

    Bearing in mind the significance of the bedrock data from the ground surface for the geological 3D modelling work, SKB decided to present excursion guides that serve in the demonstration of the bedrock geology at the ground surface in both the Forsmark and Laxemar-Simpevarp (this guide) areas. An excursion guide is also available for the Olkiluoto area in south-western Finland, which has been selected for the construction of a repository for the disposal of highly radioactive, spent nuclear fuel. The current excursion guide presents the bedrock geology and describes in detail the character of the bedrock at eight representative outcrops or outcrop areas at the ground surface in the site investigation area at Laxemar-Simpevarp and at one locality north of this area, i.e. at a total of nine localities

  3. Digital bedrock geologic map of the Andover quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG96-31A Ratcliffe, N.M., 1996, Digital bedrock geologic map of the Andover quadrangle, Vermont: USGS Open-File Report 96-31-A, 2 plates, scale...

  4. Digital compilation bedrock geologic map of the Milton quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-8A Dorsey, R, Doolan, B, Agnew, PC, Carter, CM, Rosencrantz, EJ, and Stanley, RS, 1995, Digital compilation bedrock geologic map of the Milton...

  5. Bedrock Geologic Map of Charlotte, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG09-5 Gale, M., Kim, J., Earle, H., Clark, A., Smith, T., and Petersen, K., 2009, Bedrock Geologic Map of Charlotte, Vermont: VGS Open-File Report...

  6. Bedrock Geologic Map of the Bristol, VT Quadrangle

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital data from VG13-1 Kim, J, Weber, E, and Klepeis, K, 2013, Bedrock Geologic Map of the Bristol, VT Quadrangle: Vermont Geological Survey Open File Report...

  7. Digital bedrock geologic map of the Johnson quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-2 Thompson, PJ and Thompson, TB, 1998, Digital bedrock geologic map of the Johnson quadrangle, Vermont: VGS Open-File Report VG98-2, 2 plates,...

  8. Bedrock Geologic Map of the Underhill quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG03-4B Doolan, B., Cherchetti, L., Holt, J., Ryan, J., Hengstenburg, C., and Rosencrantz, E., 2003, Bedrock Geologic Map of the Underhill...

  9. Digital bedrock geologic map of the Eden quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-3 Kim, J, Springston, G, and Gale, M, 1998, Digital bedrock geologic map of the Eden quadrangle, Vermont: VGS Open-File Report VG98-3, 2...

  10. Digital bedrock geologic map of the Cavendish quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-203A Ratcliffe, NM, 1995, Digital bedrock geologic map of the Cavendish quadrangle, Vermont: USGS Open-File Report 95-203, 2 plates, scale...

  11. Digital compilation bedrock geologic map of the Warren quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-4A Walsh, GJ, Haydock, S, Prewitt, J, Kraus, J, Lapp, E, O'Loughlin, S, and Stanley, RS, 1995, Digital compilation bedrock geologic map of the...

  12. Digital bedrock geologic map of the Saxtons River quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG96-52A Ratcliffe, NM and Armstrong, TR, 1996, Digital bedrock geologic map of the Saxtons River quadrangle, Vermont, USGS Open-File Report...

  13. Bedrock geologic map of the town of Williston, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG07-4, Kim, J., Gale, M., Thompson, P.J. and Derman, K., 2007, Bedrock geologic map of the town of Williston, Vermont: Vermont Geological Survey...

  14. Bedrock Geologic Map of the Essex Junction Quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital data from VG12-3, Gale, M., Kim. J., and Ruksznis, A., 2012, Bedrock Geologic Map of the essex Junction Quadrangle: Vermont Geological Survey Open File...

  15. Digital bedrock geologic map of the Rochester quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG96-33A Walsh, GJ and Falta, CK, 1996, Digital bedrock geologic map of the Rochester quadrangle, Vermont: USGS Open-File Report 96-33-A, 2 plates,...

  16. Digital bedrock geologic map of the Weston quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG96-526A Ratcliffe, NM and Burton, WC, 1996, Digital bedrock geologic map of the Weston quadrangle, Vermont: USGS Open-File Report 96-526, 2...

  17. Digital compilation bedrock geologic map of the Lincoln quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-5A Stanley, R, DelloRusso, V, Haydock, S, Lapp, E, O'Loughlin, S, Prewitt, J,and Tauvers, PR, 1995, Digital compilation bedrock geologic map...

  18. Digital bedrock geologic map of the Chester quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-576A Ratcliffe, N.M., 1995, Digital bedrock geologic map of the Chester quadrangle, Vermont: USGS Open-File Report 95-576, 2 plates, scale...

  19. Geology, Bedrock - BEDROCK_GEOLOGY_RGM_250K_IN: Bedrock geology of Indiana, from the Regional Geologic Map Series of the Indiana Geological Survey (Indiana Geological Survey, 1:250,000, Polygon Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — BEDROCK_GEOL_RGM_IN is a polygon shapefile that shows the bedrock geology of the state of Indiana, produced from the Indiana Geological Survey Regional Geologic Map...

  20. Hydrogeology - AQUIFER_SYSTEMS_BEDROCK_IDNR_IN: Bedrock Aquifer Systems of Indiana (Indiana Department of Natural Resources, 1:500,000, Polygon Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — AQUIFER_SYSTEMS_BEDROCK_IDNR_IN is a polygon shapefile that shows bedrock aquifer systems of the State of Indiana. The source scale of the map depicting the aquifers...

  1. Bedrock Channels: Towards a Process-Based Understanding

    Science.gov (United States)

    Parsons, D. R.; Darby, S. E.; Hackney, C. R.; Leyland, J.; Best, J.; Nicholas, A. P.; Aalto, R. E.; Horn, C. A. P. T., III; Thy, M. R.

    2014-12-01

    Most previous studies on the genesis and evolution of bedforms in large rivers have focused on aggradational bedforms within alluvial sediments, with very few investigations that concern either erosive bedform evolution or bedrock channel abrasion processes. Detailed understanding of the processes within bedrock reaches of river channels is vital if an improved understanding of formation and evolution of bedrock scours and bedforms are to be elucidated. The paper presents high-resolution bathymetry and sidescan derived from multibeam sonar (MBES) and detailed flow mapping by acoustic Doppler current profiling (ADCP) to illustrate, in intricate detail, relations between morphology, flow and sediment transport processes through a bedrock reach of the Mekong River (Cambodia) during a large flood event. A 2 by 5 km reach of the Mekong river near Sambor was surveyed with a RESON 7125 MBES system revealing incredible >40 m scour features within the bedrock substrate, with sidescan imagery also revealing the routing of alluvial sediment through the scours. A series of ADCP transects were obtained, both transverse and perpendicular to the primary downstream flow, that map the flows into, around and within these scour features. The paper will conclude by looking at how advances in measurement capability have permitted the detailed processes in such channels to be investigated for the first time at this scale.

  2. Mechanisms and Rates of Plucking of Experimental Bedrock Blocks

    Science.gov (United States)

    Harbor, D. J.; Wilkinson, C.; Helgans, E.; Kuehner, J. P.

    2015-12-01

    Plucking in bedrock channels can be the dominant erosional mechanism but is difficult to predict numerically due to variation in block shape and orientation in the flow, and the general lack of experimental data compared to alluvial sediments. In a 250 cm-long, 14 cm-wide flume, we modeled bedrock channels using a bedrock test zone consisting of flow over an upstream step of 0 to 1.6 cm, a bed slope of 0.5 to1.24%, and a changing downstream backwater control on the location of a hydraulic jump. With flow velocity from 50 to 100 cm/s and depth from 3 to 10 cm, the low-density bedrock may well characterize natural bedrock plucking events in larger rivers in flood. Plucking initiated in critical to supercritical flow near hydraulic jumps. The first blocks to move lift from both the upstream and downstream sides and then other blocks slide both up- and downstream or laterally once neighbors are removed. Initiation of motion from each new bedrock slab began with different size and shape of blocks exhibiting no protrusion relative to the surrounding bed. Block erodibility increased with step height and channel slope and following the removal of the first block. A pressure gradient within the block mass near the jump and velocity differential within the channel margin set the stage for block uplift, but flow structures likely provide the variability that initiates lift. Preliminary flow visualization using Particle Image Velocimetry aids the understanding of flow structures contributing to blocks lift. Negative and positive feedback to further plucking was observed by erosion and deposition of plucked blocks. After their initial removal, blocks can accumulate downstream and slow the flow over the eroded reach or the position of jumps and jets shift with block removal to promote further plucking.

  3. GeologicBedrock100K Units - color definitions

    Data.gov (United States)

    Vermont Center for Geographic Information — The bedrock geology was last mapped at a statewide scale 50 years ago at a scale of 1:250,000 (Doll and others, 1961). The 1961 map was compiled from 1:62,500-scale...

  4. GeologicBedrock100K Geochronology Sample Locations

    Data.gov (United States)

    Vermont Center for Geographic Information — The bedrock geology was last mapped at a statewide scale 50 years ago at a scale of 1:250,000 (Doll and others, 1961). The 1961 map was compiled from 1:62,500-scale...

  5. GeologicBedrock100K-Faults and Contacts

    Data.gov (United States)

    Vermont Center for Geographic Information — The bedrock geology was last mapped at a statewide scale 50 years ago at a scale of 1:250,000 (Doll and others, 1961). The 1961 map was compiled from 1:62,500-scale...

  6. Digital bedrock geologic map of the Plymouth quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG94-654A Walsh, G.J., and Ratcliffe, N.M., 1994, Digital bedrock geologic map of the Plymouth quadrangle, Vermont: USGS Open-File Report 94-654, 2...

  7. Bedrock hydrogeology Forsmark. Site descriptive modelling, SDM-Site Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven (SF GeoLogic AB, Taeby (Sweden))

    2008-12-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) has conducted site investigations at two different locations, the Forsmark and Laxemar-Simpevarp areas, with the objective of siting a final repository for spent nuclear fuel according to the KBS-3 concept. Site characterisation should provide all data required for an integrated evaluation of the suitability of the investigated site and an important component in the characterisation work is the development of a hydrogeological model. The hydrogeological model is used by repository engineering to design the underground facility and to develop a repository layout adapted to the site. It also provides input to the safety assessment. Another important use of the hydrogeological model is in the environmental impact assessment. This report presents the understanding of the hydrogeological conditions of the bedrock at Forsmark reached following the completion of the surface-based investigations and provides a summary of the bedrock hydrogeological model and the underlying data supporting its development. It constitutes the main reference on bedrock hydrogeology for the site descriptive model concluding the surface-based investigations at Forsmark, SDM-site, and is intended to describe the hydraulic properties and hydrogeological conditions of the bedrock at the site and to give the information essential for demonstrating understanding

  8. Bedload transport controls bedrock erosion under sediment-starved conditions

    Science.gov (United States)

    Beer, A. R.; Turowski, J. M.

    2015-07-01

    Fluvial bedrock incision constrains the pace of mountainous landscape evolution. Bedrock erosion processes have been described with incision models that are widely applied in river-reach and catchment-scale studies. However, so far no linked field data set at the process scale had been published that permits the assessment of model plausibility and accuracy. Here, we evaluate the predictive power of various incision models using independent data on hydraulics, bedload transport and erosion recorded on an artificial bedrock slab installed in a steep bedrock stream section for a single bedload transport event. The influence of transported bedload on the erosion rate (the "tools effect") is shown to be dominant, while other sediment effects are of minor importance. Hence, a simple temporally distributed incision model, in which erosion rate is proportional to bedload transport rate, is proposed for transient local studies under detachment-limited conditions. This model can be site-calibrated with temporally lumped bedload and erosion data and its applicability can be assessed by visual inspection of the study site. For the event at hand, basic discharge-based models, such as derivatives of the stream power model family, are adequate to reproduce the overall trend of the observed erosion rate. This may be relevant for long-term studies of landscape evolution without specific interest in transient local behavior. However, it remains to be seen whether the same model calibration can reliably predict erosion in future events.

  9. River longitudinal profiles and bedrock incision models: Stream power and the influence of sediment supply

    Science.gov (United States)

    Sklar, Leonard; Dietrich, William E.

    The simplicity and apparent mechanistic basis of the stream power river incision law have led to its wide use in empirical and theoretical studies. Here we identify constraints on its calibration and application, and present a mechanistic theory for the effects of sediment supply on incision rates which spotlights additional limitations on the applicability of the stream power law. On channels steeper than about 20%, incision is probably dominated by episodic debris flows, and on sufficiently gentle slopes, sediment may bury the bedrock and prevent erosion. These two limits bound the application of the stream power law and strongly constrain the possible combination of parameters in the law. In order to avoid infinite slopes at the drainage divide in numerical models of river profiles using the stream power law it is commonly assumed that the first grid cell is unchanneled. We show, however, that the size of the grid may strongly influence the calculated equilibrium relief. Analysis of slope-drainage area relationships for a river network in a Northern California watershed using digital elevation data and review of data previously reported by Hack reveal that non-equilibrium profiles may produce well defined slope-area relationships (as expected in equilibrium channels), but large differences between tributaries may point to disequilibrium conditions. To explore the role of variations in sediment supply and transport capacity in bedrock incision we introduce a mechanistic model for abrasion of bedrock by saltating bedload. The model predicts that incision rates reach a maximum at intermediate levels of sediment supply and transport capacity. Incision rates decline away from the maximum with either decreasing supply (due to a shortage of tools) or increasing supply (due to gradual bed alluviation), and with either decreasing transport capacity (due to less energetic particle movement) or increasing transport capacity (due less frequent particle impacts per unit bed

  10. Dynamic response of Antarctic ice shelves to bedrock uncertainty

    Directory of Open Access Journals (Sweden)

    S. Sun

    2014-01-01

    Full Text Available Bedrock geometry is an essential boundary condition in ice sheet modelling. The shape of the bedrock on fine scales can influences ice sheet evolution, for example through the formation of pinning points that alter grounding line dynamics. Here we test the sensitivity of the BISICLES adaptive mesh ice sheet model to small amplitude height fluctuations on different spatial scales in the bed rock topography provided by bedmap2 in the catchments of Pine Island Glacier, the Amery Ice Shelf, and a region of East Antarctica including the Denman and Totten Glaciers. We generate an ensemble of bedrock topographies by adding random noise to the bedmap2 data with amplitude determined by the accompanying estimates of bedrock uncertainty. Lower frequency coherent noise, which generates broad spatial scale (over 10s of km errors in topography with relatively gently slopes, while higher frequency noise has steeper slopes over smaller spatial scales. We find that the small amplitude fluctuations result in only minor changes in the way these glaciers evolve. However, lower frequency noise is more important than higher frequency noise even when the features have the same height amplitudes and the total noise power is maintained. This provides optimism for credible sea level rise estimates with presently achievable densities of thickness measurements. Pine Island Glacier appears to be the most sensitive to errors in bed topography, while Lambert–Amery is stable under the present day observational data uncertainty. Totten–Denman region may undergo a retreat around Totten ice shelf, where the bedrock is lower than the sea level, especially if basal melt rates increase.

  11. Digital bedrock geologic map of the Mount Snow & Readsboro quadrangles, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-DM1 Ratcliffe, NM, 1995, Digital bedrock geologic map of the Mount Snow & Readsboro quadrangles, Vermont, scale 1:24000, The bedrock...

  12. Quantitative bedrock geology of the conterminous United States of America

    Science.gov (United States)

    Peucker-Ehrenbrink, Bernhard; Miller, Mark W.

    2002-10-01

    We quantitatively analyze the area-age distribution of bedrock based on data from the most recent geologic map of the conterminous United States of America [, 1974a, 1974b], made available in digital form by the United States Geologic Survey. The area-age distribution agrees surprisingly well with older data [, 1949] but provides much higher temporal resolution. The mean stratigraphic age of all sedimentary bedrock is ˜134 Myr; that of Tertiary-Cambrian sediments is ˜104 Myr. The analysis also reveals area coverage of some minor lithologies, such as ultramafic rocks that cover ˜0.15% of the conterminous United States. Area coverage of 162 lithostratigraphic units is made available as an Excel data sheet.

  13. Site Characterization of Deep Bedrock with Integrated Geophysical Survey

    Science.gov (United States)

    Son, J.; Kim, C.; Eun, S. B.

    2015-12-01

    In order to utilize the deep underground storage facility stable for a long time, precise site characterization is required before its construction. Various kinds of geophysical survey as well as drilling and geological survey should be used to know the status of deep bedrock. A research had been conducted to make the site characterization of deep bedrock for several years, and to achieve its purpose, integrated geophysical survey were applied to the test area which had gneiss bedrock. DC resistivity survey for six surficial profiles was conducted to find the appropriate location of drilling survey. Cross-hole/surface-to-hole resistivity tomography survey and borehole reflection radar survey were applied to the drill holes after its installation completed. Three bore holes of which length was 500 meter were drilled to investigate the status of deep bedrock, and cross-hole tomography survey was applied between two boreholes among these. Also borehole reflection radar survey was conducted to another two boreholes. Deep seated fracture zones which were not identified with the surficial geological and resistivity survey were found through the analysis of tomography section. Fracture zones were consisted of steep slope fault and these were also identified with the result of borehole radar section. After the basic survey was completed, one of three holes was extended to the depth of 1 km. Radar reflection survey which was only available to the deep drill-hole was applied. Because steel casing was installed to the depth of 750 m to stabilize the extended drill-hole, resistivity method was not available and borehole radar reflection method was only available among the geophysical method used in this research. Through results of radar reflection survey, several fracture zones were identified for the newly extended section of drill hole and some of those facture has relatively large size and passed through the bore hole.

  14. Bedrock incision by bedload: insights from direct numerical simulations

    Science.gov (United States)

    Aubert, Guilhem; Langlois, Vincent J.; Allemand, Pascal

    2016-04-01

    Bedload sediment transport is one of the main processes that contribute to bedrock incision in a river and is therefore one of the key control parameters in the evolution of mountainous landscapes. In recent years, many studies have addressed this issue through experimental setups, direct measurements in the field, or various analytical models. In this article, we present a new direct numerical approach: using the classical methods of discrete-element simulations applied to granular materials, we explicitly compute the trajectories of a number of pebbles entrained by a turbulent water stream over a rough solid surface. This method allows us to extract quantitatively the amount of energy that successive impacts of pebbles deliver to the bedrock, as a function of both the amount of sediment available and the Shields number. We show that we reproduce qualitatively the behaviour observed experimentally by Sklar and Dietrich (2001) and observe both a "tool effect" and a "cover effect". Converting the energy delivered to the bedrock into an average long-term incision rate of the river leads to predictions consistent with observations in the field. Finally, we reformulate the dependency of this incision rate with Shields number and sediment flux, and predict that the cover term should decay linearly at low sediment supply and exponentially at high sediment supply.

  15. Soil mechanics and analysis of soils overlying cavitose bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Drumm, E.C.

    1987-08-01

    The stability of the residual soils existing at the West Chestnut Ridge Site, Oak Ridge Reservation, Tennessee, was evaluated. The weathered bedrock below this residual soil contains numerous solution cavities, and several karst features were identified. The West Chestnut Ridge site was evaluated with respect to deformation and collapse of the residual soil into the bedrock cavities. A finite element analysis investigated the effects of bedrock cavity radius, thickness of soil overburden, and surface surcharge upon the deformational and stability characteristics of the residual soil. The results indicate that for small cavity radii, the thickness of the soil cover has little effect on the zone of yielded soil. For large cavity radii, a smaller zone of distressed soil occurs under thick soil cover than under thin soil cover. Dimensionless curves are presented to enable the prediction of the vertical extent of the zone of yielded soil for a range of site geometries. Although the thick soil deposits (100 feet or greater) typically found on the ridges result in high stresses adjacent to the cavity, the area of the distressed or yielded soil is small and unlikely to extend to the surface. In addition, the surface deformation or subsidence is expected to be minimal. Thus, the siting of waste facilities on the ridges where the overburden is maximum would tend to reduce the effects of deformation into the cavities. 29 refs., 37 figs., 7 tabs.

  16. Novice to Expert Cognition During Geologic Bedrock Mapping

    Science.gov (United States)

    Petcovic, H. L.; Libarkin, J.; Hambrick, D. Z.; Baker, K. M.; Elkins, J. T.; Callahan, C. N.; Turner, S.; Rench, T. A.; LaDue, N.

    2011-12-01

    Bedrock geologic mapping is a complex and cognitively demanding task. Successful mapping requires domain-specific content knowledge, visuospatial ability, navigation through the field area, creating a mental model of the geology that is consistent with field data, and metacognition. Most post-secondary geology students in the United States receive training in geologic mapping, however, not much is known about the cognitive processes that underlie successful bedrock mapping, or about how these processes change with education and experience. To better understand cognition during geologic mapping, we conducted a 2-year research study in which 67 volunteers representing a range from undergraduate sophomore to 20+ years professional experience completed a suite of cognitive measures plus a 1-day bedrock mapping task in the Rocky Mountains, Montana, USA. In addition to participants' geologic maps and field notes, the cognitive suite included tests and questionnaires designed to measure: (1) prior geologic experience, via a self-report survey; (2) geologic content knowledge, via a modified version of the Geoscience Concept Inventory; (3) visuospatial ability, working memory capacity, and perceptual speed, via paper-and-pencil and computerized tests; (4) use of space and time during mapping via GPS tracking; and (5) problem-solving in the field via think-aloud audio logs during mapping and post-mapping semi-structured interviews. Data were examined for correlations between performance on the mapping task and other measures. We found that both geological knowledge and spatial visualization ability correlated positively with accuracy in the field mapping task. More importantly, we found a Visuospatial Ability × Geological Knowledge interaction, such that visuospatial ability positively predicted mapping performance at low, but not high, levels of geological knowledge. In other words, we found evidence to suggest that visuospatial ability mattered for bedrock mapping for the

  17. A probabilistic framework for the cover effect in bedrock erosion

    Science.gov (United States)

    Turowski, Jens; Hodge, Rebecca

    2016-04-01

    Bedrock erosion rates in mountain rivers are driven by impacting bedload particles and are modulated by two conflicting affects. Rising sediment flux leads to an increasing number of impacts and thus larger erosion rates (the tools effect). However, when sediment supply gets too large, sediment particles sit on the bed protecting it from impacts and thereby decreasing the erosion rate (the cover effect). Previous flume experiments and numerical models have predicted a wide range of formulations for the relationship between sediment flux and sediment cover. Here, we propose a simple probabilistic framework to mathematically describe the cover effect, in which the development of cover is as a function of the probability of sediment deposition on bedrock or sediment-covered areas of the bed. The framework can incorporate empirical or modelling results and provides a neat link to process interpretations. We compare model predictions with results from both a cellular automaton model of grain dynamics, and from flume experiments. The framework is able to reproduce many of the observed behaviours, and thus provides a way of unifying the range of different results that have previously been reported. Further, we present a simple first order model for the dynamic evolution of bed cover over time that could be incorporated into channel morphodynamic models.

  18. Plant response to nutrient availability across variable bedrock geologies

    Science.gov (United States)

    Castle, S.C.; Neff, J.C.

    2009-01-01

    We investigated the role of rock-derived mineral nutrient availability on the nutrient dynamics of overlying forest communities (Populus tremuloides and Picea engelmanni-Abies lasiocarpa v. arizonica) across three parent materials (andesite, limestone, and sandstone) in the southern Rocky Mountains of Colorado. Broad geochemical differences were observed between bedrock materials; however, bulk soil chemistries were remarkably similar between the three different sites. In contrast, soil nutrient pools were considerably different, particularly for P, Ca, and Mg concentrations. Despite variations in nutrient stocks and nutrient availability in soils, we observed relatively inflexible foliar concentrations and foliar stoichiometries for both deciduous and coniferous species. Foliar nutrient resorption (P and K) in the deciduous species followed patterns of nutrient content across substrate types, with higher resorption corresponding to lower bedrock concentrations. Work presented here indicates a complex plant response to available soil nutrients, wherein plant nutrient use compensates for variations in supply gradients and results in the maintenance of a narrow range in foliar stoichiometry. ?? 2008 Springer Science+Business Media, LLC.

  19. Landslides and the interplay of infiltration, soil permeability and bedrock exfiltration on steep slopes

    Science.gov (United States)

    Schneider, Philipp; Brönnimann, Cornelia; Stähli, Manfred; Seibert, Jan

    2015-04-01

    Shallow landslides pose substantial risks to people and infrastructure in mountain areas. Their occurrence is influenced by soil and bedrock characteristics and triggered by precipitation-induced pore water dynamics. The bedrock may drain or contribute to groundwater in the overlying soil depending on permeability, degree of fracturing, saturation and hydraulic head. Here, we present a case study from Central Switzerland designed to illuminate a situation where such interactions are decisive and investigate runoff formation processes at hillslopes prone to slide. The bedrock in the study area represents a succession of fissured conglomerate-sandstone and weathered marlstone layers, overlaid by a gleysol. Evidence of a temporally confined aquifer in bedrock fractures was gathered from a severe storm event in August 2005. First, a geological model of the investigated slope derived from electrical resistivity tomography surveys, borehole data, and bedrock outcrops formed the basis for test site instrumentation. Second, the soil moisture and the groundwater response to 32 storm events were monitored in different soil and bedrock layers. Although the subsoil horizons are not particularly permeable, a fast and substantial rise of hydraulic heads in the bedrock was observed, suggesting that rapid percolation through bedrock fractures caused the immediate increase of pore water pressures. The data document how pore water pressure builds up in fractured bedrock below a low-permeable soil during storms, which may trigger shallow landslides. Third, sprinkling experiments were conducted on subplots with variable rainfall intensities and different dye tracers to identify preferential infiltration, percolation and storm runoff formation at the hillslope. Brilliant blue dye stained the entire organic topsoil, vertical soil fractures, and macropores. Lateral drainage in the subsoil or at the soil-bedrock interface was not observed; drainage was limited to the organic topsoil. In

  20. Event scale variability of mixed alluvial-bedrock channel dynamics

    Science.gov (United States)

    Cook, Kristen; Turowski, Jens; Hovius, Niels

    2015-04-01

    The relationship between flood events and fluvial behavior is critical for understanding how rivers may respond to the changing hydrologic forcing that may accompany climate change. In mixed bedrock-alluvial rivers, the response of the system to a flood event can be affected by a large number of factors, including coarse sediment availability in the channel, sediment supply from the hillslopes, bedrock-controlled changes in channel width and planform, and the shape of the hydrograph. We use the Daan River Gorge in western Taiwan as a case study to directly observe the effect of individual flood events on channel evolution. The 1200 m long and up to 20 m deep bedrock gorge formed in response to uplift of the riverbed during the 1999 Chi-Chi earthquake. The extremely rapid pace of change ensures that flood events have measurable and often dramatic effects on the channel. Taiwan is subject to both summer typhoons and a spring monsoon, resulting in numerous channel-altering floods with a range of magnitudes. Discharge is therefore highly variable, ranging from 5 to over 2000 m3/s, and changes in the channel are almost entirely driven by discrete flood events. Since early 2009 we have monitored changes in the gorge with repeated RTK GPS surveys, laser rangefinder measurements, and terrestrial LIDAR surveys. Six rainfall stations and five water level gauges provide hydrological data for the basin. We find a distinct relationship between flood magnitude and the magnitude of geomorphic change; however, we do not find a clear relationship between flood characteristics and the direction of change - whether the channel experienced aggradation or erosion in a particular flood. Upstream coarse sediment supply and the influence of abrupt changes in channel width on bedload flux through the gorge appear to have important influences on the channel response. The better understand these controls, we use the model sedFlow (Heimann et al., 2014) to explore the effects of interactions

  1. Influence of bedrock on river hydrodynamics and channel geometry

    Science.gov (United States)

    Rennie, C. D.; Church, M. A.; Venditti, J. G.; Bomhof, J.; Adderley, C.

    2013-12-01

    We present an acoustic Doppler current profiler (aDcp) survey of a 524 km long reach of Fraser River, British Columbia, Canada, as it passes through the Fraser Canyons. The channel alternates between gravel-bedded reaches that are incised into semi-consolidated glacial deposits and bedrock-bound reaches (7.7% of the reach between the towns of Quesnel and Hope). A continuous centreline aDcp survey was employed to measure longitudinal variation in slope, depth, depth-averaged velocity, and shear velocity. A total of 71 aDcp sectional surveys throughout the reach provided section widths (w), section-averaged depths (d), velocity distributions, and discharge (Q). Finally, air photo analysis using Google imagery provided channel widths at 0.5 km spacing. The survey reach was subdivided into 10 morphological sub-reaches, which ranged from alluvial gravel-bed reaches with relatively moderate slope to steep non-alluvial rock-walled canyons. The resulting data provide a unique opportunity to evaluate the influence of bedrock confinement on river hydrodynamics and channel geometry. Continuous centreline longitudinal aDcp data and the widths from air photo analysis were grouped within each sub-reach based on presence of bedrock confinement on both banks, either bank, or neither bank. The results demonstrate that river widths decreased and water depths, flow velocities, and shear velocities increased from the alluvial sub-reaches to the semi-alluvial reaches to the canyon reaches. Within each sub-reach, locations with bedrock encroachment on both banks were also narrower and deeper, but had lower depth-averaged velocity and shear velocity. Sectional geometry data were homogenized along the river (to compensate increasing flows at tributary junctions) by computing w/Q^{1/2} and d/Q^{1/3}, following commonly observed scaling relations. Alluvial reaches are 2.3x wider than rock-bound reaches (from the more abundant imagery data) and 0.60x as deep (from aDcp sections), implying

  2. Ultramafic-derived arsenic in a fractured bedrock aquifer

    Science.gov (United States)

    Ryan, P.C.; Kim, J.; Wall, A.J.; Moen, J.C.; Corenthal, L.G.; Chow, D.R.; Sullivan, C.M.; Bright, K.S.

    2011-01-01

    In the fractured bedrock aquifer of northern Vermont, USA, As concentrations in groundwater range from elements, indicating that As was introduced to the ultramafic rocks during metasomatism by fluids derived from the subducting slab. Evidence from sequential chemical extraction, X-ray diffraction (XRD) and stoichiometric analysis indicates that the majority of the As is located in antigorite and magnesite (MgCO3) with lesser amounts in magnetite (Fe3O4). Hydrochemistry of monitoring wells drilled into fractured ultramafic rock in a groundwater recharge area with no anthropogenic As source reveals above background As (2-9??g/L) and an Mg-HCO3 hydrochemical signature that reflects dissolution of antigorite and magnesite, confirming that As in groundwater can be derived from ultramafic rock dissolution. Arsenic mobility in groundwater affected by ultramafic rock dissolution may be enhanced by alkaline pH values and relatively high HCO3- concentrations. ?? 2011 Elsevier Ltd.

  3. Bedrock hydrogeochemistry Forsmark. Site descriptive modelling SDM-Site Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Laaksoharju, Marcus (Geopoint AB, Sollentuna (Sweden)); Smellie, John (Conterra AB, Partille (Sweden)); Tullborg, Eva-Lena (Terralogica, Graabo (Sweden)); Gimeno, Maria (Univ. of Zaragoza, Zaragoza (Spain)); Hallbeck, Lotta (Microbial Analytics, Goeteborg (Sweden)); Molinero, Jorge (Amphos XXI Consulting S.L., Barcelona (Spain)); Waber, Nick (Univ. of Bern, Bern (Switzerland))

    2008-12-15

    The overall objectives of the hydrogeochemical site description for Forsmark are to establish a detailed understanding of the hydrogeochemical conditions at the site, and to use this understanding to develop models that address the needs identified by the safety assessment groups during the site investigation phase. Issues of concern to safety assessment are radionuclide transport and technical barrier behaviour, both of which are dependent on the chemistry of groundwater and porewater and their evolution with time. The specific aims of the hydrogeochemical work were: To document the hydrogeochemistry at the Forsmark site with focus on the development of conceptual models to describe and visualise the site. To provide relevant parameter values to be used for safety assessment calculations. To provide the hydrogeochemical basis for the modelling work by other teams, in particular hydrogeology. To take account of the feedback from the SR-Can safety assessment work that bears relevance to the hydrogeochemical modelling work. The work has involved the development of descriptive and mathematical models for groundwaters in relation to rock domains, fracture domains and deformation zones. In this report, the groundwaters have been interpreted in relation to their origin, evolution and composition, which require close integration with geological, climatological and hydrogeological information. Past climate changes are one of the major driving forces for long-term hydrogeochemical changes (hundreds to thousands of years) and are, therefore, of fundamental importance for understanding the palaeohydrogeological, palaeohydrogeochemical and present evolution of groundwater in the Fennoscandian crystalline bedrock. In contrast, redox buffer capacity of the bedrock will minimise the effects on changes in alkalinity and redox at repository depths, therefore limiting the variations in pH and Eh significantly, regardless of major changes in groundwater composition. There is

  4. Peak Ground Acceleration on Bedrock of Natanz, Iran

    Directory of Open Access Journals (Sweden)

    Bakouchi .emad

    2016-12-01

    Full Text Available The present paper was done under the title of peak ground acceleration(PGA on bedrock for natanz city. A set of seismic sources, historical and instrumental seismicity data within the radius of 150 kilometers from the city center since the year 1700 until now has been collected and used. Kijko[2000] method has been applied for estimating the seismic parameters considering lack of suitable seismic data, inaccuracy of the available information and uncertainty of magnitude in different periods. The calculations were performed by using the logic tree method, three weighted attenuation relationships were used; including Ghodrati et al (2007, 0.4; Ambraseys et al (1996, 0.3 ; Campbellbozorgnia (2000, 0.3 . The SEISRISKIII (1987 software was used to calculate the earthquake hazard. The results of this analysis were submitted for 10% and 2% probability of event in 50 years.

  5. Shallow bedrock limits groundwater seepage-based headwater climate refugia

    Science.gov (United States)

    Briggs, Martin; Lane, John; Snyder, Craig D.; White, Eric A.; Johnson, Zachary; Nelms, David L.; Hitt, Nathaniel P.

    2017-01-01

    Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive to seasonal and long-term air temperature dynamics. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We employ rapid, cost-effective passive seismic measurements to evaluate the variable thickness of the shallow colluvial and alluvial aquifer sediments along a headwater stream supporting cold water-dependent brook trout (Salvelinus fontinalis) in Shenandoah National Park, VA, USA. Using a mean depth to bedrock of 2.6 m, numerical models predicted strong sensitivity of shallow aquifer temperature to the downward propagation of surface heat. The annual temperature dynamics (annual signal amplitude attenuation and phase shift) of potential seepage sourced from the shallow modeled aquifer were compared to several years of paired observed stream and air temperature records. Annual stream water temperature patterns were found to lag local air temperature by ∼8–19 d along the stream corridor, indicating that thermal exchange between the stream and shallow groundwater is spatially variable. Locations with greater annual signal phase lag were also associated with locally increased amplitude attenuation, further suggestion of year-round buffering of channel water temperature by groundwater seepage. Numerical models of shallow groundwater temperature that incorporate regional expected climate warming trends indicate that the summer cooling capacity of this groundwater seepage will be reduced over time, and lower-elevation stream sections may no longer serve as larger

  6. The hillslope-storage Boussinesq model for non-constant bedrock slope

    NARCIS (Netherlands)

    Hilberts, A.G.J.; Loon, van E.E.; Troch, P.A.A.; Paniconi, C.

    2004-01-01

    In this study the recently introduced hill slope-storage Boussinesq (hsB) model is cast in a generalized formulation enabling the model to handle non-constant bedrock slopes (i.e. bedrock profile curvature). This generalization extends the analysis of hydrological behavior to hillslopes of arbitrary

  7. Testing bedrock incision models: Holocene channel evolution, High Cascades, Oregon

    Science.gov (United States)

    Sweeney, K. E.; Roering, J. J.; Fonstad, M. A.

    2013-12-01

    There is abundant field evidence that sediment supply controls the incision of bedrock channels by both protecting the bed from incision and providing tools to incise the bed. Despite several theoretical models for sediment-dependent bedrock abrasion, many investigations of natural channel response to climatic, lithologic, or tectonic forcing rely on the stream power model, which does not consider the role of sediment. Here, we use a well-constrained fluvial channel cut into a Holocene lava flow in the High Cascades, Oregon to compare incision predictions of the stream power model and of the full physics of theoretical models for saltation-abrasion incision by bedload and suspended load. The blocky andesite of Collier lava flow erupted from Collier Cone ~1500 years ago, paving over the existing landscape and erasing fine-scale landscape dissection. Since the eruption, a 6 km stream channel has been incised into the lava flow. The channel is comprised of three alluvial reaches with sediment deposits up to 2 m thick and two bedrock gorges with incision of up to 8 m, with larger magnitude incision in the upstream gorge. Abraded forms such as flutes are present in both gorges. Given the low magnitude and duration of modern snowmelt flow in the channel, it is likely that much of the incision was driven by sediment-laden outburst floods from the terminus of Collier Glacier, which is situated just upstream of the lava flow and has produced two outburst floods in the past 100 years. This site is well suited for comparing incision models because of the relatively uniform lithology of the lava flow and our ability to constrain the timing and depth of incision using the undissected lava surface above the channel as an initial condition. Using a simple finite difference scheme with airborne-Lidar-derived pre-incision topography as an initial condition, we predict incision in the two gorges through time with both stream power and sediment-dependent models. Field observations

  8. On the reliability of manually produced bedrock lineament maps

    Science.gov (United States)

    Scheiber, Thomas; Viola, Giulio; Fredin, Ola; Jarna, Alexandra; Gasser, Deta; Łapinska-Viola, Renata

    2016-04-01

    Manual extraction of topographic features from digital elevation models (DEMs) is a commonly used technique to produce lineament maps of fractured basement areas. There are, however, several sources of bias which can influence the results. In this study we investigated the influence of the factors (a) scale, (b) illumination azimuth and (c) operator on remote sensing results by using a LiDAR (Light Detection and Ranging) DEM of a fractured bedrock terrain located in SW Norway. Six operators with different backgrounds in Earth sciences and remote sensing techniques mapped the same LiDAR DEM at three different scales and illuminated from three different directions. This resulted in a total of 54 lineament maps which were compared on the basis of number, length and orientation of the drawn lineaments. The maps show considerable output variability depending on the three investigated factors. In detail: (1) at larger scales, the number of lineaments drawn increases, the line lengths generally decrease, and the orientation variability increases; (2) Linear features oriented perpendicular to the source of illumination are preferentially enhanced; (3) The reproducibility among the different operators is generally poor. Each operator has a personal mapping style and his/her own perception of what is a lineament. Consequently, we question the reliability of manually produced bedrock lineament maps drawn by one person only and suggest the following approach: In every lineament mapping study it is important to define clear mapping goals and design the project accordingly. Care should be taken to find the appropriate mapping scale and to establish the ideal illumination azimuths so that important trends are not underrepresented. In a remote sensing project with several persons included, an agreement should be reached on a given common view on the data, which can be achieved by the mapping of a small test area. The operators should be aware of the human perception bias. Finally

  9. Estimated Depth to Bedrock of Iowa as a 110 meter pixel_32bit Imagine Format Raster Dataset

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This raster dataset represents the depth to bedrock from the land surface. It was derived by subtracting a bedrock surface elevation layer from the NED 30 meter...

  10. Temperature logging of groundwater in bedrock wells for geothermal gradient characterization in New Hampshire, 2012

    Science.gov (United States)

    Degnan, James; Barker, Gregory; Olson, Neil; Wilder, Leland

    2012-01-01

    The U.S. Geological Survey, in cooperation with the New Hampshire Geological Survey, measured the fluid temperature of groundwater in deep bedrock wells in the State of New Hampshire in order to characterize geothermal gradients in bedrock. All wells selected for the study had low water yields, which correspond to low groundwater flow from fractures. This reduced the potential for flow-induced temperature changes that would mask the natural geothermal gradient in the bedrock. All the wells included in this study were privately owned, and permission to use the wells was obtained from homeowners before logging.

  11. Quality of bedrock groundwater in western Finland, with special reference to nitrogen compounds

    Directory of Open Access Journals (Sweden)

    Karro, E.

    1999-12-01

    Full Text Available Monitoring of bedrock aquifers utilized for water supply in the Vaasa region, western Finland, suggests slight changes in the chemical composition of groundwater resulting both from natural and anthropogenic factors. Applying the permissible limits for parameters in drinking water reveals that the groundwater quality is generally good. Groundwater occurring in fractures and fissures of the crystalline bedrock is protected from anthropogenic pollution by clay and till deposits with low permeability. Temporally, the contents of nitrogen compounds in groundwater exhibit a decreasing trend. Reducing conditions prevailing in bedrock aquifers are reflected in elevated ammonium, iron and manganese contents in water.

  12. Groundwater chemistry of a nuclear waste reposoitory in granite bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Rydberg, J.

    1981-09-01

    This report concerns the prediction of the maximum dissolution rate for nuclear waste stored in the ground. That information is essential in judging the safety of a nuclear waste repository. With a limited groundwater flow, the maximum dissolution rate coincides with the maximum solubility. After considering the formation and composition of deep granite bedrock groundwater, the report discusses the maximum solubility in such groundwater of canister materials, matrix materials and waste elements. The parameters considered are pH, Eh and complex formation. The use of potential-pH (Pourbaix) diagrams is stressed; several appendixes are included to help in analyzing such diagrams. It is repeatedly found that desirable basic information on solution chemistry is lacking, and an international cooperative research effort is recommended. The report particularly stresses the lack of reliable data about complex formation and hydrolysis of the actinides. The Swedish Nuclear Fuel Safety (KBS) study has been used as a reference model. Notwithstanding the lack of reliable chemical data, particularly for the actinides and some fission products, a number of essential conclusions can be drawn about the waste handling model chosen by KBS. (1) Copper seems to be highly resistant to groundwater corrosion. (2) Lead and titanium are also resistant to groundwater, but inferior to copper. (3) Iron is not a suitable canister material. (4) Alumina (Al/sub 2/O/sub 3/) is not a suitable canister material if groundwater pH goes up to or above 10. Alumina is superior to copper at pH < 9, if there is a risk of the groundwater becoming oxidizing. (5) The addition of vivianite (ferrous phosphate) to the clay backfill around the waste canisters improves the corrosion resistance of the metal canisters, and reduces the solubility of many important waste elements. This report does not treat the migration of dissolved species through the rock.

  13. Bedrock Hydrogeology - Groundwater flow modelling. Site investigation SFR

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Johan [Geosigma AB, Uppsala (Sweden); Follin, Sven [SF GeoLogic AB, Taeby (Sweden); Oden, Magnus [SKB, Stockholm (Sweden)

    2013-05-15

    The hydrogeological model developed for the SFR extension project (PSU) consists of 40 geologically modelled deformation zones (DZ) and 8 sub-horizontal structural-hydraulic features, called SBAstructures, not defined in the geological model. However, some of the SBA-structures coincide with what is defined as unresolved possible deformation zones (Unresolved PDZ) in the geological modelling. In addition, the hydrogeological model consists of a stochastic discrete fracture network (DFN) model intended for the less fractured rock mass volumes (fracture domains) between the zones and the SBA-structures, and a stochastic fracture model intended to handle remaining Unresolved PDZs in the geological modelling not modelled as SBA-structures in the hydrogeological modelling. The four structural components of the bedrock in the hydrogeological model, i.e. DZ, SBA, Unresolved PDZ and DFN, are assigned hydraulic properties in the hydrogeological model based on the transmissivities interpreted from single-hole hydraulic tests. The main objective of the present work is to present the characteristics of the hydrogeological model with regard to the needs of the forthcoming safety assessment SR-PSU. In concrete words, simulated data are compared with measured data, i.e. hydraulic heads in boreholes and tunnel inflow to the existing repository (SFR). The calculations suggest that the available data for flow model calibration cannot be used to motivate a substantial adjustment of the initial hydraulic parameterisation (assignment of hydraulic properties) of the hydrogeological model. It is suggested that uncertainties in the hydrogeological model are studied in the safety assessment SR-PSU by means of a large number of calculation cases. These should address hydraulic heterogeneity of deterministic structures (DZ and SBA) and realisations of stochastic fractures/fracture networks (Unresolved PDZ and DFN) within the entire SFR Regional model domain.

  14. Attributes for NHDPlus Catchments (Version 1.1) in the Conterminous United States: Bedrock Geology

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the area of bedrock geology types in square meters compiled for every catchment of NHDPlus for the conterminous United States. The source...

  15. Bedrock geology of the Arabian Peninsula and selected adjacent areas (geo2bg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The data set for this coverage includes arcs, polygons, and polygon labels that outline and describe the general geologic age and type of bedrock of the Arabian...

  16. Bedrock geologic map of parts of the Eden, Albany, Lowell, and Irasburg quadrangles, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG09-4 (Digitized draft of VG97-5): Kim, J., 2009, Bedrock geologic map of parts of the Eden, Albany, Lowell, and Irasburg quadrangles, VGS...

  17. Digital and preliminary bedrock geologic map of the Pico Peak quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-226A Walsh, G. J., and Ratcliffe, N.M., 1998, Digital and preliminary bedrock geologic map of the Pico Peak quadrangle, Vermont: USGS...

  18. Digital bedrock geologic map of the Morrisville quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-1 Springston, G., Kim, J., and Applegate, G.S., 1998, Digital bedrock geologic map of the Morrisville quadrangle, Vermont: VGS Open-File...

  19. Digital and preliminary bedrock geologic map of the Wallingford quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-335A Burton, WC, and Ratcliffe, NM, 2000, Digital and preliminary bedrock geologic map of the Wallingford quadrangle, Vermont: USGS Open-File...

  20. Digital compilation bedrock geologic map of part of the Waitsfield quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG96-03 Digital compilation bedrock geologic map of part of the Waitsfield quadrangle, Vermont: VGS Open-File Report VG96-3A, 2 plates, scale...

  1. Digital and preliminary bedrock geologic map of the Mount Carmel quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-330A Ratcliffe, N.M., and Walsh, G. J., 1998, Digital and preliminary bedrock geologic map of the Mount Carmel quadrangle, Vermont: USGS...

  2. Digital bedrock geologic map of the Mount Holly and Ludlow quadrangles, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG94-229A Walsh, G.J., Ratcliffe, N.M., Dudley, J.B., and Merrifield, T., 1994, Digital bedrock geologic map of the Mount Holly and Ludlow...

  3. Digital compilation bedrock geologic map of the Mt. Ellen quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-6A Stanley, RS, Walsh, G, Tauvers, PR, DiPietro, JA, and DelloRusso, V, 1995, Digital compilation bedrock geologic map of the Mt. Ellen...

  4. Digital and preliminary bedrock geologic map of the Chittenden quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG97-854A Ratcliffe, NM, 1997, Digital and preliminary bedrock geologic map of the Chittenden quadrangle, Vermont: USGS Open-File Report 97-854, 1...

  5. Digital bedrock geologic map of the Mt. Mansfield quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG99-3 Thompson, PJ and Thompson, TB, 1999, Digital bedrock geologic map of the Mt. Mansfield quadrangle, Vermont: VGS Open-File Report VG99-3, 3...

  6. Digital bedrock geologic map of parts of the Huntington, Richmond, Bolton and Waterbury quadrangles, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-9A Thompson, PJ and Thompson, TB, 1995, Digital bedrock geologic map of parts of the Huntington, Richmond, Bolton and Waterbury quadrangles,...

  7. Digital bedrock geologic map of the Gilson Mountain quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-7A Doolan, B, 1995, Digital bedrock geologic map of the Gilson Mountain quadrangle, Vermont: VGS Open-File Report VG95-7A, 2 plates, scale...

  8. Digital and preliminary bedrock geologic map of the Rutland quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-121A Ratcliffe, N.M., 1998, Digital and preliminary bedrock geologic map of the Rutland quadrangle, Vermont: USGS Open-File Report 98-121-A, 1...

  9. Bedrock Data from Western Cape Cod, Massachusetts (WELLSITE shapefile, Geographic, NAD27)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cores collected from recent drilling in western Cape Cod, Massachusetts provide insight into the topography and petrology of the underlying bedrock. Cores from 64...

  10. Bedrock Geology of the turkey Creek Drainage Basin, Jefferson County, Colorado

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geospatial data set describes bedrock geology of the Turkey Creek drainage basin in Jefferson County, Colorado. It was digitized from maps of fault locations...

  11. Lithogeochemical Character of Near-Surface Bedrock in the Connecticut, Housatonic and Thames River Basins

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data layer shows the generalized lithologic and geochemical (lithogeochemical) character of near-surface bedrock in the Connecticut, Housatonic, and Thames...

  12. Measured and Inferred Bedrock Faults in the Boulder-Weld Coal Field (frifaultu)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This file is a digital line representation of measured and inferred bedrock faults in the Boulder-Weld coal field, Denver Basin, Colorado. This file was created as...

  13. Hillslope hydrological modeling : the role of bedrock geometry and hillslope-stream interaction

    NARCIS (Netherlands)

    Shahedi, K.

    2008-01-01

    Keywords: Hillslope hydrology, hydrological modeling, bedrock geometry, boundary condition, numerical solution. This thesis focuses on hillslope subsurface flow as a dominant control on the hydrological processes defining the catchment response to rainfall. Due to the difficulties associated with

  14. Lithogeochemical Character of Near-Surface Bedrock in the New England Coastal Basins

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geographic information system (GIS) data layer shows the generalized lithologic and geochemical, termed lithogeochemical, character of near-surface bedrock in...

  15. Graffiti for science: Qualitative detection of erosional patterns through bedrock erosion painting

    Science.gov (United States)

    Beer, Alexander R.; Kirchner, James W.; Turowski, Jens M.

    2016-04-01

    Bedrock erosion is a crucial constraint on stream channel incision, and hence whole landscape evolution, in steep mountainous terrain and tectonically active regions. Several interacting processes lead to bedrock erosion in stream channels, with hydraulic shear detachment, plucking, and abrasion due to sediment impacts generally being the most efficient. Bedrock topography, together with the sediment tools and cover effects, regulate the rate and spatial pattern of in situ surface change. Measurements of natural bedrock erosion rates are valuable for understanding the underlying process physics, as well as for modelling landscape evolution and designing engineered structures. However, quantifying spatially distributed bedrock erosion rates in natural settings is challenging and few such measurements exist. We studied spatial bedrock erosion in a 30m-long bedrock gorge in the Gornera, a glacial meltwater stream above Zermatt. This stream is flushed episodically with sediment-laden streamflow due to hydropower operations upstream, with negligible discharge in the gorge in between these flushing events. We coated several bedrock surface patches with environmentally safe, and water-insoluble outdoor paint to document the spatial pattern of surface abrasion, or to be more precise, to document its driving forces. During four consecutive years, the change of the painted areas was recorded repeatedly with photographs before the painting was renewed. These photographs visually documented the spatial patterns of vertical erosion (channel incision), of lateral erosion (channel widening) and of downstream-directed erosion (channel clearance). The observed qualitative patterns were verified through comparison to quantitative change detection analyses based on annual high-resolution terrestrial laser scanning surveys of the bedrock surfaces. Comparison of repeated photographs indicated a temporal cover effect and a general height limit of the tools effect above the streambed

  16. Topographic roughness as a signature of the emergence of bedrock in eroding landscapes

    Science.gov (United States)

    Milodowski, D. T.; Mudd, S. M.; Mitchard, E. T. A.

    2015-10-01

    Rock is exposed at the Earth surface when rates of erosion locally exceed rates of soil production. The thinning of soils and emergence of bedrock has implications spanning geomorphology, ecology and hydrology. Soil-mantled hillslopes are typically shaped by diffusion-like sediment transport processes that act to smooth topography through time, generating the familiar smooth, convex hillslope profiles that are common in low relief landscapes. Other processes, however, can roughen the landscape. Bedrock emergence can produce rough terrain; in this contribution we exploit the contrast between rough patches of bedrock outcrop and smooth, diffusion-dominated soil to detect bedrock outcrops. Specifically, we demonstrate that the local variability of surface normal vectors, measured from 1 m resolution airborne LiDAR data, can be used as a topographic signature to identify areas within landscapes where rock exposure is present. We then use this roughness metric to investigate the transition from soil-mantled to bedrock hillslopes as erosion rates increase in two transient landscapes, Bald Rock Basin, which drains into the Middle Fork Feather River, California, and Harrington Creek, a tributary of the Salmon River, Idaho. Rather than being abrupt, as predicted by traditional soil production models, in both cases the transition from fully soil-mantled to bedrock hillslopes is gradual and spatially heterogeneous, with rapidly eroding hillslopes supporting a patchwork of bedrock and soil that is well documented by changes in topographic roughness, highlighting the utility of this metric for testing hypotheses concerning the emergence of bedrock and adding to a growing body of evidence that indicates the persistence of partial soil mantles in steep, rapidly eroding landscapes.

  17. Experimental research on engineering geological mechanical model of strip mining below thin bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W.; Sui, W. [CUMT, Xuzhou (China). School of Resources and Earth Science

    2004-03-15

    With respect to thin bedrock strata found in Taiping coal mining area of Yanzhou, mechanism and controlling factors of overlying strata and ground movement deformation induced by strip mining under the condition of thin bedrock were studied by means of engineering geological model test. The destruction process, forms, and ranges of overlying strata and the rules of ground movement were revealed, providing a theoretical basis for engineering practice. 10 refs., 3 figs.

  18. Bedrock mapping of buried valley networks using seismic reflection and airborne electromagnetic data

    Science.gov (United States)

    Oldenborger, G. A.; Logan, C. E.; Hinton, M. J.; Pugin, A. J.-M.; Sapia, V.; Sharpe, D. R.; Russell, H. A. J.

    2016-05-01

    In glaciated terrain, buried valleys often host aquifers that are significant groundwater resources. However, given the range of scales, spatial complexity and depth of burial, buried valleys often remain undetected or insufficiently mapped. Accurate and thorough mapping of bedrock topography is a crucial step in detecting and delineating buried valleys and understanding formative valley processes. We develop a bedrock mapping procedure supported by the combination of seismic reflection data and helicopter time-domain electromagnetic data with water well records for the Spiritwood buried valley aquifer system in Manitoba, Canada. The limited spatial density of water well bedrock observations precludes complete depiction of the buried valley bedrock topography and renders the water well records alone inadequate for accurate hydrogeological model building. Instead, we leverage the complementary strengths of seismic reflection and airborne electromagnetic data for accurate local detection of the sediment-bedrock interface and for spatially extensive coverage, respectively. Seismic reflection data are used to define buried valley morphology in cross-section beneath survey lines distributed over a regional area. A 3D model of electrical conductivity is derived from inversion of the airborne electromagnetic data and used to extrapolate buried valley morphology over the entire survey area. A spatially variable assignment of the electrical conductivity at the bedrock surface is applied to different features of the buried valley morphology identified in the seismic cross-sections. Electrical conductivity is then used to guide construction of buried valley shapes between seismic sections. The 3D locus of points defining each morphological valley feature is constructed using a path optimization routine that utilizes deviation from the assigned electrical conductivities as the cost function. Our resulting map represents a bedrock surface of unprecedented detail with more

  19. Combining airborne electromagnetic and geotechnical data for automated depth to bedrock tracking

    Science.gov (United States)

    Christensen, Craig William; Pfaffhuber, Andreas Aspmo; Anschütz, Helgard; Smaavik, Tone Fallan

    2015-08-01

    Airborne electromagnetic (AEM) survey data was used to supplement geotechnical investigations for a highway construction project in Norway. Heterogeneous geology throughout the survey and consequent variable bedrock threshold resistivity hindered efforts to directly track depth to bedrock, motivating us to develop an automated algorithm to extract depth to bedrock by combining both boreholes and AEM data. We developed two variations of this algorithm: one using simple Gaussian or inverse distance weighting interpolators, and another using ordinary kriging and combined probability distribution functions of input parameters. Evaluation shows that for preliminary surveys, significant savings in boreholes required can be made without sacrificing bedrock model accuracy. In the case study presented, we estimate data collection savings of 1000 to 10,000 NOK/km (c. 160 to 1600 USD/km) would have been possible for early phases of the investigation. However, issues with anthropogenic noise, low signal, and uncertainties in the inversion model likely reduced the comparative advantage that including AEM provided. AEM cannot supersede direct sampling where the model accuracy required exceed the resolution possible with the geophysical measurements. Nevertheless, with the algorithm we can identify high probability zones for shallow bedrock, identify steep or anomalous bedrock topography, and estimate the spatial variability of depth at earlier phases of investigation. Thus, we assert that our method is still useful where detailed mapping is the goal because it allows for more efficient planning of secondary phases of drilling.

  20. Present-day mass changes for the Greenland ice sheet and their interaction with bedrock adjustment

    Directory of Open Access Journals (Sweden)

    M. Olaizola

    2011-12-01

    Full Text Available Since the launch in 2002 of the Gravity Recovery and Climate Experiment (GRACE satellites, several estimates of the mass balance of the Greenland Ice Sheet (GrIS have been produced. To obtain ice mass changes estimates, data need to be corrected for the effect of deformation changes of the Earth's crust. This is usually done by independently modeling the Glaciological Isostatic Adjustment (GIA trend and then by removing it from the data. Recently, Wu et al. (2010 proposed a new method to simultaneously estimate GIA and the present-day ice mass change, reporting an ice mass loss of around half of the previously published estimates and a general bedrock subsidence concentrated in the central parts of Greenland. This subsidence appears to be counterintuitive since the ice sheet is loosing mass at present. It was suggested by the authors that this could be a new evidence for additional net past ice accumulation.

    In this study, a 3-D ice-sheet model with a surface mass balance forcing based on a mass balance gradient approach has been used to: (a analyze the bedrock response to changes in the ice load in order to evaluate whether bedrock subsidence and ice thinning can exist simultaneously; (b study the magnitude and the pattern of the bedrock movement; and (c evaluate if present-day bedrock subsidence could be the result of a net past mass accumulation.

    Under a sine forcing of the annual temperature, that mimics the temperature variations in the Holocene, mass changes yield a delay of the bedrock response of 200 years. Thinning of the ice as well as bedrock subsidence coexist during this period with an order of magnitude equal to the observations by Wu et al. (2010. Although, the resulting pattern of bedrock changes differs considerable: instead of the general bedrock subsidence reported before, we found areas of bedrock uplift as well as areas of bedrock subsidence. A simulation since the last glacial maximum (with the

  1. Quantifying fluvial bedrock erosion using repeat terrestrial Lidar

    Science.gov (United States)

    Cook, Kristen

    2013-04-01

    The Da'an River Gorge in western Taiwan provides a unique opportunity to observe the formation and evolution of a natural bedrock gorge. The 1.2 km long and up to 20 m deep gorge has formed since 1999 in response to uplift of the riverbed during the Chi-Chi earthquake. The extremely rapid pace of erosion enables us to observe both downcutting and channel widening over short time periods. We have monitored the evolution of the gorge since 2009 using repeat RTK GPS surveys and terrestrial Lidar scans. GPS surveys of the channel profile are conducted frequently, with 24 surveys to date, while Lidar scans are conducted after major floods, or after 5-9 months without a flood, for a total of 8 scans to date. The Lidar data are most useful for recording erosion of channel walls, which is quite episodic and highly variable along the channel. By quantifying the distribution of wall erosion in space and time, we can improve our understanding of channel widening processes and of the development of the channel planform, particularly the growth of bends. During the summer of 2012, the Da'an catchment experienced two large storm events, a meiyu (plum rain) event on June 10-13 that brought 800 mm of rain and a typhoon on August 1-3 that brought 650 mm of rain. The resulting floods had significant geomorphic effects on the Da'an gorge, including up to 10s of meters of erosion in some sections of the gorge walls. We quantify these changes using Lidar surveys conducted on June 7, July 3, and August 30. Channel wall collapses also occur in the absence of large floods, and we use scans from August 23, 2011 and June 7, 2012 to quantify erosion during a period that included a number of small floods, but no large ones. This allows us to compare the impact of 9 months of normal conditions to the impact of short-duration extreme events. The observed variability of erosion in space and time highlights the need for 3D techniques such as terrestrial Lidar to properly quantify erosion in this

  2. Laboratory measurements of grain-bedrock interactions using inertial sensors.

    Science.gov (United States)

    Maniatis, Georgios; Hoey, Trevor; Hodge, Rebecca; Valyrakis, Manousos; Drysdale, Tim

    2016-04-01

    Sediment transport in steep mountain streams is characterized by the movement of coarse particles (diameter c.100 mm) over beds that are not fully sediment-covered. Under such conditions, individual grain dynamics become important for the prediction of sediment movement and subsequently for understanding grain-bedrock interaction. Technological advances in micro-mechanical-electrical systems now provide opportunities to measure individual grain dynamics and impact forces from inside the sediments (grain inertial frame of reference) instead of trying to infer them indirectly from water flow dynamics. We previously presented a new prototype sensor specifically developed for monitoring sediment transport [Maniatis et al. EGU 2014], and have shown how the definition of the physics of the grain using the inertial frame and subsequent derived measurements which have the potential to enhance the prediction of sediment entrainment [Maniatis et al. 2015]. Here we present the latest version of this sensor and we focus on beginning of the cessation of grain motion: the initial interaction with the bed after the translation phase. The sensor is housed in a spherical case, diameter 80mm, and is constructed using solid aluminum (density = 2.7 kg.m-3) after detailed 3D-CAD modelling. A complete Inertial Measurement Unit (a combination of micro- accelerometer, gyroscope and compass) was placed at the center of the mass of the assembly, with measurement ranges of 400g for acceleration, and 1200 rads/sec for angular velocity. In a 0.9m wide laboratory flume, bed slope = 0.02, the entrainment threshold of the sensor was measured, and the water flow was then set to this value. The sensor was then rolled freely from a static cylindrical bar positioned exactly on the surface of the flowing water. As the sensor enters the flow we record a very short period of transport (1-1.5 sec) followed by the impact on the channel bed. The measured Total Kinetic Energy (Joules) includes the

  3. 2D soil and engineering-seismic bedrock modeling of eastern part of Izmir inner bay/Turkey

    Science.gov (United States)

    Pamuk, Eren; Akgün, Mustafa; Özdağ, Özkan Cevdet; Gönenç, Tolga

    2017-02-01

    Soil-bedrock models are used as a base when the earthquake-soil common behaviour is defined. Moreover, the medium which is defined as bedrock is classified as engineering and seismic bedrock in itself. In these descriptions, S-wave velocity is (Vs) used as a base. The mediums are called soil where the Vs is < 760 m/s, the bigger ones are called bedrock as well. Additionally, the parts are called engineering bedrock where the Vs is between 3000 m/s and 760 m/s, the parts where are bigger than 3000 m/s called seismic bedrock. The interfacial's horizontal topography where is between engineering and seismic bedrock is effective on earthquake's effect changing on the soil surface. That's why, 2D soil-bedrock models must be used to estimate the earthquake effect that could occur on the soil surface. In this research, surface wave methods and microgravity method were used for occuring the 2D soil-bedrock models in the east of İzmir bay. In the first stage, velocity values were obtained by the studies using surface wave methods. Then, density values were calculated from these velocity values by the help of the empiric relations. 2D soil-bedrock models were occurred based upon both Vs and changing of density by using these density values in microgravity model. When evaluating the models, it was determined that the soil is 300-400 m thickness and composed of more than one layers in parts where are especially closer to the bay. Moreover, it was observed that the soil thickness changes in the direction of N-S. In the study area, geologically, it should be thought the engineering bedrock is composed of Bornova melange and seismic bedrock unit is composed of Menderes massif. Also, according to the geophysical results, Neogene limestone and andesite units at between 200 and 400 m depth show that engineering bedrock characteristic.

  4. High-resolution monitoring of fluvial bedrock erosion in a natural gorge

    Science.gov (United States)

    Beer, Alexander R.; Turowski, Jens M.

    2014-05-01

    Morphological evolution of terrestrial and planetary landscapes is of increasing interest in the geosciences. In mountainous regions stream development and stream shape as a consequence of the interaction of uplift and erosion is fundamental for surface formation. Bedrock stream sections are prevalent that are routings for water and sediments. Hence, the correct description of bedrock channel evolution is fundamental for landscape modelling. To analyse how in situ erosion rates depend on factors like discharge, sediment transport and topography, there is a need of highly resolved topographic field data that so far is not available. Here we present preliminary outcomes of a change detection study from the Gorner Gorge above Zermatt, Switzerland. The outflow of the Gorner glacier (the Gornera stream) is captured most of the time by a water intake for hydropower production. However this intake is flushed twice a day in summer to purge settled sediments. Then the Gornera, charged with erosive bedload, runs along its natural stream bed that cuts through a roche moutonnée. This bedrock section (25m long, 5m wide and 8m deep) was surveyed repeatedly twice a year benefiting from nearly dry bed conditions during water capturing. A Leica ScanStation C10 was used for capturing high density point clouds (aspired average point spacing 5mm) of the bedrock surfaces. Referencing each of the various scanning positions was conducted using Leica HDS targets attached to fixed anchor bolts in the bedrock, that were surveyed locally with a total station. Resulting DEMs were used to calculate DEMs of difference (DoDs) for the bedrock walls and a huge boulder residing on the gravel bed. Erosion rates are visualised and discussed in respect of to the local spatial arrangement of the bedrock to the stream flow and water level.

  5. Controls of bedrock geochemistry on soil and plant nutrients in Southeastern Utah

    Science.gov (United States)

    Neff, J.C.; Reynolds, R.; Sanford, R.L.; Fernandez, D.; Lamothe, P.

    2006-01-01

    The cold deserts of the Colorado Plateau contain numerous geologically and geochemically distinct sedimentary bedrock types. In the area near Canyonlands National Park in Southeastern Utah, geochemical variation in geologic substrates is related to the depositional environment with higher concentrations of Fe, Al, P, K, and Mg in sediments deposited in alluvial or marine environments and lower concentrations in bedrock derived from eolian sand dunes. Availability of soil nutrients to vegetation is also controlled by the formation of secondary minerals, particularly for P and Ca availability, which, in some geologic settings, appears closely related to variation of CaCO3 and Ca-phosphates in soils. However, the results of this study also indicate that P content is related to bedrock and soil Fe and Al content suggesting that the deposition history of the bedrock and the presence of P-bearing Fe and Al minerals, is important to contemporary P cycling in this region. The relation between bedrock type and exchangeable Mg and K is less clear-cut, despite large variation in bedrock concentrations of these elements. We examined soil nutrient concentrations and foliar nutrient concentration of grasses, shrubs, conifers, and forbs in four geochemically distinct field sites. All four of the functional plant groups had similar proportional responses to variation in soil nutrient availability despite large absolute differences in foliar nutrient concentrations and stoichiometry across species. Foliar P concentration (normalized to N) in particular showed relatively small variation across different geochemical settings despite large variation in soil P availability in these study sites. The limited foliar variation in bedrock-derived nutrients suggests that the dominant plant species in this dryland setting have a remarkably strong capacity to maintain foliar chemistry ratios despite large underlying differences in soil nutrient availability. ?? 2006 Springer Science

  6. Dredged bedrock samples from the Amerasia Basin, Arctic Ocean

    Science.gov (United States)

    Brumley, K. J.; Mukasa, S. B.; O'Brien, T. M.; Mayer, L. A.; Chayes, D. N.

    2013-12-01

    Between 2008-2012, as part of the U.S. Extended Continental Shelf project in the Amerasia Basin, Arctic Ocean, 17 dredges were successfully collected sampling the first rock outcrops in the Chukchi Borderland and surrounding regions for the purpose of describing the geologic nature of the bathymetric features in this area. Multiple lines of evidence indicate that the specimens were collected from submarine rock exposures and were not samples of ice rafted debris, common in the ice covered waters of the Arctic Ocean. Using the USCGC Healy, each dredge was collected along very steep slopes (>35 degrees) measured with high resolution multibeam swath bathymety data. Each haul yielded samples of similar lithologies and identical metamorphic grade with manganese crusts on the surfaces exposed to seawater and fresh surfaces where the rocks were broken from outcrop. High tension pulls on the dredge line also indicated sampling of bedrock exposures. Dredged samples from a normal fault scarp in the central Chukchi Borderland consisted of Silurian (c. 430 Ma) orthogneisses that intruded older (c. 487-500 Ma) gabbros and luecogranties that were all metamorphosed to amphibolite grade (Brumley et al., 2011). Samples from the northern Northwind Ridge consisted of metasediments (greenschist facies) interpreted to have been deposited in a proximal arc setting with detrital zircon U-Pb age peaks at 434, 980 Ma with lesser peaks between 500-600, 1100-2000 Ma, and rare 2800 Ma grains (Brumley et al, 2010). Other dredges in the region of the Northwind Ridge yielded deformed and metamorphosed calcareous sandstones and low-grade phyllites (O'Brien et al., 2013). Taken together these rocks indicate a relationship to the Pearya Terrane of northern Ellesmere Island and S.W. Svalbard that were thought to represent a Cambro-Ordovician volcanic arc terrane that was involved in Caledonian orogenesis (Brumley et al., 2011). These findings constrain plate tectonic reconstruction models and bring

  7. Do Titan's river channels carve into ice bedrock or loose regolith?

    Science.gov (United States)

    Collins, G. C.; Sklar, L. S.; Litwin, K. L.; Polito, P. J.

    2012-04-01

    Final results from our experiments investigating the abrasion resistance and strength of polycrystalline ice and ice/contaminant mixtures at Titan temperatures allow us to update the calculations of Collins (2005), which examined the ease of fluvial incision into ice bedrock on Titan. If Titan’s stream channels run over exposed bedrock, the rate of channel downcutting is limited by the supply of sediment particles to abrade the bedrock surface, or by the production of pluckable blocks from joints in the bedrock. By adapting the equations of Sklar and Dietrich (2004) to Titan, we estimate the relative rate of bedrock incision caused by abrasion of sediment particles, and find that bedrock on Titan responds like a welded tuff or a quartzite on Earth, rather than the weak sandstone-like response found initially by Collins (2005). Using the range of values for the HLS drainage basins used by Perron et al. (2006) and the sediment sizes observed by Keller et al. (2008), we adjust the unknown sediment supply rate into the channels to find the upper limit of the bedrock incision rate during rainstorm-runoff events. Maximum incision rates are about 1 micron per hour. If typical peak runoff events only last for a few hours, it would take on the order of 105 to 106 rainstorms for a channel to incise one meter into the solid bedrock. However, the mass flux of sediment from farther upstream required to erode this much bedrock implies that transportation of loose sediment would lower the entire catchment area 100 times faster than the bedrock in the channel is lowered. This is logically unsustainable, and leaves us with two options for erosion of the stream channels. One option is that the stream channels are even more supply limited than they are in our maximization calculation, and channel incision on Titan is an even slower process than outlined above. A more likely explanation is that Titan’s streams are instead primarily cutting into bedrock that is pre-fractured into

  8. Quality of water in the fractured-bedrock aquifer of New Hampshire

    Science.gov (United States)

    Moore, Richard Bridge

    2004-01-01

    Over the past few decades, New Hampshire has experienced considerable population growth, which is forcing some communities to look for alternative public and private water supplies in the bedrock aquifer. Because the quality of water from the aquifer can vary, the U.S. Geological Survey statistically analyzed well data from 1,353 domestic and 360 public-supply bedrock wells to characterize the ground water. The domestic-well data were from homeowner-collected samples analyzed by the New Hampshire Department of Environmental Services (NHDES) Environmental Laboratory from 1984 to 1994. Bedrock water in New Hampshire often contains high concentrations of iron, manganese, arsenic, and radon gas. Water samples from 21 percent of the domestic bedrock wells contained arsenic above the U.S. Environmental Protection Agency (USEPA) 10 micrograms per liter (?g/L) drinking-water standard for public-water supplies, and 96 percent had radon concentrations greater than the USEPA-proposed 300 picocurie per liter (pCi/L) standard for public-water supplies. Some elevated fluoride concentrations (2 percent of samples) were above the 4 milligrams per liter (mg/L) USEPA drinking-water standard for public-water supplies. Water from the bedrock aquifer also typically is soft to moderately hard, and has a pH greater than 7.0. Variations in bedrock water quality were discernable when the data were compared to lithochemical groupings of the bedrock, indicating that the type of bedrock has an effect on the quality of water in the bedrock aquifer of New Hampshire. Ground-water samples from the metasedimentary lithochemical group have greater concentrations of total iron and total manganese than do the felsic and mafic igneous lithochemical groups. Ground-water samples from the felsic igneous group have higher concentrations of total fluoride than do those from the other lithochemical groups. For arsenic, the calcareous metasedimentary group was identified, using the public-supply database, as

  9. Episodic bedrock erosion by gully-head migration, Colorado High Plains, USA

    Science.gov (United States)

    Rengers, Francis; Tucker, G.E.; Mahan, Shannon

    2016-01-01

    This study explores the frequency of bedrock exposure in a soil-mantled low-relief (i.e. non-mountainous) landscape. In the High Plains of eastern Colorado, gully headcuts are among the few erosional features that will incise through the soil mantle to expose bedrock. We measured the last time of bedrock exposure using optically stimulated luminescence dating of alluvial sediment overlying bedrock in gully headcuts. Our dating suggests that headcuts in adjacent gullies expose bedrock asynchronously, and therefore, the headcuts are unlikely to have been triggered by a base-level drop in the trunk stream. This finding supports the hypothesis that headcuts can develop locally in gullies as a result of focused scour in locations where hydraulic stress during a flash flood is sufficiently high, and/or ground cover is sufficiently weak, to generate a scour hole that undermines vegetation. Alluvium dating also reveals that gullies have been a persistent part of this landscape since the early Holocene. 

  10. Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

    Energy Technology Data Exchange (ETDEWEB)

    Moenkkoenen, H. [WSP Finland Oy, Helsinki (Finland)

    2012-04-15

    In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

  11. Bedrock Nitrogen Contributes to Increased Carbon Storage in Temperate Conifer Forests of Northern California, USA

    Science.gov (United States)

    Morford, S. L.; Houlton, B. Z.; Dahlgren, R. A.

    2010-12-01

    Identifying mechanisms by which nitrogen (N) enters ecosystems is crucial to modeling carbon (C) storage and earth system responses to rising CO2 emissions. Paradigms of nutrient cycling posit that N enters ecosystems solely from the atmosphere; however, rocks contain 99% of all fixed N on Earth, implying a potentially widespread source of ecologically available N. We tested the hypothesis that bedrock N contributes to increased N fertility and C storage of temperate conifer forests underlain by N-rich bedrock in northern California, USA. We used a paired sampling design to measure total N and C, and N stable isotope ratios (15N/14N) of surface mineral soils, bedrock, and foliage from similar forests that differed in parent material: the first site on N-rich (680 ppm N) metasedimentary rock, the second site on N-poor (55 ppm N) igneous rock. In addition, we performed a regional analysis of C storage in aboveground tree biomass using Forest Inventory and Analysis (FIA) plot data (n = 82) from conifer forests on N-rich and N-poor bedrock to examine for C by N interactions at the regional scale. The N content of soils and conifer needles was elevated by more than 50% in the forest underlain by N-rich bedrock, with soil C pools elevated by 60% in N-rich sites. Further, 15N/14N of rock, soils, and plants were indistinguishable in sites underlain by N-rich lithology, whereas foliar 15N/14N from N-poor site was depleted 20‰ relative to rock. Finally, the regional data pointed to substantial effects of N-rich rock on total forest C storage; ecosystem C pools were 40% higher in forests with geologic N than sites with N-poor bedrock minerals. These results suggest that rock weathering can profoundly alter ecosystem N and C cycles, implying an overlooked pathway of N input to terrestrial ecosystems.

  12. An ice flow modeling perspective on bedrock adjustment patterns of the Greenland ice sheet

    Directory of Open Access Journals (Sweden)

    M. Olaizola

    2012-11-01

    Full Text Available Since the launch in 2002 of the Gravity Recovery and Climate Experiment (GRACE satellites, several estimates of the mass balance of the Greenland ice sheet (GrIS have been produced. To obtain ice mass changes, the GRACE data need to be corrected for the effect of deformation changes of the Earth's crust. Recently, a new method has been proposed where ice mass changes and bedrock changes are simultaneously solved. Results show bedrock subsidence over almost the entirety of Greenland in combination with ice mass loss which is only half of the currently standing estimates. This subsidence can be an elastic response, but it may however also be a delayed response to past changes. In this study we test whether these subsidence patterns are consistent with ice dynamical modeling results. We use a 3-D ice sheet–bedrock model with a surface mass balance forcing based on a mass balance gradient approach to study the pattern and magnitude of bedrock changes in Greenland. Different mass balance forcings are used. Simulations since the Last Glacial Maximum yield a bedrock delay with respect to the mass balance forcing of nearly 3000 yr and an average uplift at present of 0.3 mm yr−1. The spatial pattern of bedrock changes shows a small central subsidence as well as more intense uplift in the south. These results are not compatible with the gravity based reconstructions showing a subsidence with a maximum in central Greenland, thereby questioning whether the claim of halving of the ice mass change is justified.

  13. Comparison of planform multi-channel network characteristics of alluvial and bedrock constrained large rivers

    Science.gov (United States)

    Carling, P. A.; Meshkova, L.; Robinson, R. A.

    2011-12-01

    The Mekong River in northern Cambodia is an multi-channel mixed bedrock-alluvial river but it was poorly researched until present. Preliminary study of the Mekong geomorphology was conducted by gathering existing knowledge of its geological and tectonic settings, specific riparian vegetation and ancient alluvial terraces in which the river has incised since the Holocene. Altogether this process has allowed a geomorphological portrait of the river to be composed within the Quaternary context. Following this outline, the planform characteristics of the Mekong River network are compared, using analysis of channel network and islands configurations, with the fluvial patterns of the Orange River (South Africa), Upper Columbia River (Canada) and the Ganga River (India, Bangladesh). These rivers are selected as examples of multi-channel mixed bedrock alluvial, anastomosed alluvial and braided alluvial rivers respectively. Network parameters such as channel bifurcation angles asymmetry, sinuosity, braid intensity and island morphometric shape metrics are compared and contrasted between bedrock and alluvial systems. In addition, regional and local topographic trend surfaces produced for each river planform help explain the local changes in river direction and the degree of anastomosis, and distinguish the bedrock-alluvial rivers from the alluvial rivers. Variations between planform characteristics are to be explained by channel forming processes and in the case of mixed bedrock-alluvial rivers mediated by structural control. Channel metrics (derived at the reach-scale) provide some discrimination between different multi-channel patterns but are not always robust when considered singly. In contrast, island shape metrics (obtained at subreach-scale) allow robust discrimination between alluvial and bedrock systems.

  14. Bedrock Control on Slope Gradients in the Luckiamute Watershed, Central Coast Range, Oregon: Implications for Sediment Transport and Storage

    Science.gov (United States)

    Taylor, S. B.

    2002-12-01

    The Luckiamute River watershed drains 815 sq km along the east flank of the Coast Range in west-central Oregon. Active mountain building and extreme precipitation patterns result in a dynamic geomorphic system characterized by seasonal flooding and slope failure. Style of surficial process and landform associations are controlled by topographic position, underlying bedrock geology, and resistance to erosion. Bedrock map units are grouped into four lithospatial domains, these include the Siletz River Volcanics Domain (south), the Tyee Domain (west-southwest), the Yamhill-Intrusive Domain (north-northwest), and the Valley Fill-Spencer Domain (east). The Siletz River Domain comprises 19% of the watershed and is mainly seafloor basalt. The Tyee Domain (29% of total area) is underlain by arkosic sandstone lithofacies with local mafic intrusives. The Yamhill-Intrusive Domain occupies 23% of the watershed and is characterized by outcrop of marine siltstone and mafic intrusives. The Valley Fill-Spencer Domain (29%) is underlain by a patchwork of marine sandstones and Quaternary alluvium. Hillslope landforms and colluvial processes dominate the Siletz River, Tyee, and Yamhill domains, whereas fluvial landforms and alluvial processes are characteristic of the Valley Fill Domain. GIS-based analyses of USGS 10-meter DEMs elucidate associations between lithospatial domains and slope gradients. Average gradients for the Valley Fill, Siletz, Yamhill, and Tyee domains are 3.2 (n = 2290702 10-m cells), 12.7 (n = 1510287 10-m cells), 11.9 (n = 1926899 10-m cells), and 14.5 (n = 2409140 10-m cells) degrees, respectively. The Tyee Domain is associated with significantly steeper slopes on average compared to the other three domains. In addition, greater than 14% of the Tyee Domain area has slopes greater than 25 degrees, compared to less than 1% for the Valley Fill Domain, and less than 8% for the Siletz and Yamhill domains. Results of the slope analyses are consistent with debris

  15. Mechanical effects of excavation rebound of arch dam bedrock and better concreting time of dam body

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In high ground stress zone, rebound deformation of excavation of arch dam bedrock has a significant impact on the structural behavior, design and construction of arch dam. Based on the analysis of mechanical effects of excavation rebound, with both stress and deformation as two constraint conditions and deformation modulus as a controlling condition, the method to determine a better concreting time of dam body was put forward. All of these play an important guiding role in the excavation of dam bedrock and the construction of dam body.

  16. Spatial pattern of groundwater arsenic occurrence and association with bedrock geology in greater augusta, maine

    Science.gov (United States)

    Yang, Q.; Jung, H.B.; Culbertson, C.W.; Marvinney, R.G.; Loiselle, M.C.; Locke, D.B.; Cheek, H.; Thibodeau, H.; Zheng, Yen

    2009-01-01

    In New England, groundwater arsenic occurrence has been linked to bedrock geology on regional scales. To ascertain and quantify this linkage at intermediate (100-101 km) scales, 790 groundwater samples from fractured bedrock aquifers in the greater Augusta, Maine area are analyzed, and 31% of the sampled wells have arsenic concentrations >10 ??g/L. The probability of [As] exceeding 10 ??g/L mapped by indicator kriging is highest in Silurian pelite-sandstone and pelite-limestone units (???40%). This probability differs significantly (p 10 ??g/L arsenic in groundwater. ?? 2009 American Chemical Society.

  17. Neoseismotectonics and glacial isostatic uplift. Deformations and changes of prevailing conditions in the Swedish bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Moerner, N.A. [Stockholm Univ. (Sweden)

    1997-04-01

    The conclusions from this contribution are that no bedrock repository can be considered to be safely placed in the bedrock at the event of new glaciations, which are to be expected over Sweden in 5, 23, and 60 thousand years AP (following the astronomical, natural or long-term variability). Instead, there are all reasons to expect that such a repository would be seriously damaged, and constitute a threat to the biosphere on Earth. These conclusions are based on an extensive observational network of records on the multiple glacial dynamics and the interaction of different variables. 24 refs.

  18. The keystone species of Precambrian deep bedrock biosphere belong to Burkholderiales and Clostridiales

    Directory of Open Access Journals (Sweden)

    L. Purkamo

    2015-11-01

    Full Text Available The bacterial and archaeal community composition and the possible carbon assimilation processes and energy sources of microbial communities in oligotrophic, deep, crystalline bedrock fractures is yet to be resolved. In this study, intrinsic microbial communities from six fracture zones from 180–2300 m depths in Outokumpu bedrock were characterized using high-throughput amplicon sequencing and metagenomic prediction. Comamonadaceae-, Anaerobrancaceae- and Pseudomonadaceae-related OTUs form the core community in deep crystalline bedrock fractures in Outokumpu. Archaeal communities were mainly composed of Methanobacteraceae-affiliating OTUs. The predicted bacterial metagenomes showed that pathways involved in fatty acid and amino sugar metabolism were common. In addition, relative abundance of genes coding the enzymes of autotrophic carbon fixation pathways in predicted metagenomes was low. This indicates that heterotrophic carbon assimilation is more important for microbial communities of the fracture zones. Network analysis based on co-occurrence of OTUs revealed the keystone genera of the microbial communities belonging to Burkholderiales and Clostridiales. Bacterial communities in fractures resemble those found from oligotrophic, hydrogen-enriched environments. Serpentinization reactions of ophiolitic rocks in Outokumpu assemblage may provide a source of energy and organic carbon compounds for the microbial communities in the fractures. Sulfate reducers and methanogens form a minority of the total microbial communities, but OTUs forming these minor groups are similar to those found from other deep Precambrian terrestrial bedrock environments.

  19. Bedrock geologic map of the Jay and North Troy area, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG97-04C Stanley, RS, and Roy, D, 1997, Bedrock geologic map of the Jay and North Troy area, Vermont: VGS Open-File Report VG97-04c, scale 1:24000....

  20. Digital compilation bedrock geologic map of the South Mountain quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-3A Stanley, R.S., DelloRusso, V., Tauvers, P.R., DiPietro, J.A., Taylor, S., and Prahl, C., 1995, Digital compilation bedrock geologic map of...

  1. Muon Tomography of Ice-filled Cleft Systems in Steep Bedrock Permafrost: A Proposal

    CERN Document Server

    Ihl, Matthias

    2010-01-01

    In this note, we propose a novel application of geoparticle physics, namely using a muon tomograph to study ice-filled cleft systems in steep bedrock permafrost. This research could significantly improve our understanding of high alpine permafrost in general and climate-permafrost induced rockfall in particular.

  2. The keystone species of Precambrian deep bedrock biosphere belong to Burkholderiales and Clostridiales

    Science.gov (United States)

    Purkamo, L.; Bomberg, M.; Kietäväinen, R.; Salavirta, H.; Nyyssönen, M.; Nuppunen-Puputti, M.; Ahonen, L.; Kukkonen, I.; Itävaara, M.

    2015-11-01

    The bacterial and archaeal community composition and the possible carbon assimilation processes and energy sources of microbial communities in oligotrophic, deep, crystalline bedrock fractures is yet to be resolved. In this study, intrinsic microbial communities from six fracture zones from 180-2300 m depths in Outokumpu bedrock were characterized using high-throughput amplicon sequencing and metagenomic prediction. Comamonadaceae-, Anaerobrancaceae- and Pseudomonadaceae-related OTUs form the core community in deep crystalline bedrock fractures in Outokumpu. Archaeal communities were mainly composed of Methanobacteraceae-affiliating OTUs. The predicted bacterial metagenomes showed that pathways involved in fatty acid and amino sugar metabolism were common. In addition, relative abundance of genes coding the enzymes of autotrophic carbon fixation pathways in predicted metagenomes was low. This indicates that heterotrophic carbon assimilation is more important for microbial communities of the fracture zones. Network analysis based on co-occurrence of OTUs revealed the keystone genera of the microbial communities belonging to Burkholderiales and Clostridiales. Bacterial communities in fractures resemble those found from oligotrophic, hydrogen-enriched environments. Serpentinization reactions of ophiolitic rocks in Outokumpu assemblage may provide a source of energy and organic carbon compounds for the microbial communities in the fractures. Sulfate reducers and methanogens form a minority of the total microbial communities, but OTUs forming these minor groups are similar to those found from other deep Precambrian terrestrial bedrock environments.

  3. Modeled Top of the Older Bedrock Geomodel Unit (pmtop_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The pmtop_f grid represents the modeled elevation of the top of the Older Bedrock geomodel unit at a 500 foot resolution. It is one grid of a geomodel that consists...

  4. Microbial co-occurrence patterns in deep Precambrian bedrock fracture fluids

    Science.gov (United States)

    Purkamo, Lotta; Bomberg, Malin; Kietäväinen, Riikka; Salavirta, Heikki; Nyyssönen, Mari; Nuppunen-Puputti, Maija; Ahonen, Lasse; Kukkonen, Ilmo; Itävaara, Merja

    2016-05-01

    The bacterial and archaeal community composition and the possible carbon assimilation processes and energy sources of microbial communities in oligotrophic, deep, crystalline bedrock fractures is yet to be resolved. In this study, intrinsic microbial communities from groundwater of six fracture zones from 180 to 2300 m depths in Outokumpu bedrock were characterized using high-throughput amplicon sequencing and metagenomic prediction. Comamonadaceae-, Anaerobrancaceae- and Pseudomonadaceae-related operational taxonomic units (OTUs) form the core community in deep crystalline bedrock fractures in Outokumpu. Archaeal communities were mainly composed of Methanobacteriaceae-affiliating OTUs. The predicted bacterial metagenomes showed that pathways involved in fatty acid and amino sugar metabolism were common. In addition, relative abundance of genes coding the enzymes of autotrophic carbon fixation pathways in predicted metagenomes was low. This indicates that heterotrophic carbon assimilation is more important for microbial communities of the fracture zones. Network analysis based on co-occurrence of OTUs revealed possible "keystone" genera of the microbial communities belonging to Burkholderiales and Clostridiales. Bacterial communities in fractures resemble those found in oligotrophic, hydrogen-enriched environments. Serpentinization reactions of ophiolitic rocks in Outokumpu assemblage may provide a source of energy and organic carbon compounds for the microbial communities in the fractures. Sulfate reducers and methanogens form a minority of the total microbial communities, but OTUs forming these minor groups are similar to those found in other deep Precambrian terrestrial bedrock environments.

  5. Rios de leito rochoso: aspectos geomorfológicos fundamentais / Bedrock Rivers: fundamental geomorphologic aspects

    Directory of Open Access Journals (Sweden)

    Adalto Gonçalves de Lima

    2010-11-01

    Full Text Available ResumoOs estudos sobre rios de leito rochoso desenvolveram-se grandemente nas ultimas décadas, mas no Brasil, esses estudos ainda são incipientes. Considerando o estado recente do desenvolvimento desse tema e a escassez de trabalhos em língua portuguesa, e feita uma revisão dos aspectos geomorfológicos fundamentais desses rios com base nos estudos atuais. Primeiramente analisa-se o conceito de canais fluviais de leito rochoso. Em segundo lugar são analisados os princípios hidráulicos que governam a erosão em leitos rochosos. Finalmente, os processos erosivos de abrasão, arranque e cavitação são descritos a partir das pesquisas atuais. AbstractThe studies about bedrock rivers have been largely developed in last decades, but in Brazil these studies are still incipient. Considering the recent development of this theme and the scarcity of related research in Portuguese language, it is conducted a revision of fundamental geomorphologic aspects of bedrock rivers based on current studies. First of all, it is analyzed the bedrock river concept and after that, it is analyzed the hydraulic principles that govern the bedrock erosion. Finally, the erosive processes of abrasion, plucking and cavitation are described from current researches.

  6. Piezometric response in shallow bedrock at CB1: Implications for runoff generation and landsliding

    Science.gov (United States)

    Montgomery, David R.; Dietrich, William E.; Heffner, John T.

    2002-12-01

    Experimental observations comparing two steep unchanneled valleys in the Oregon Coast Range, one intensively instrumented (CB1) and the other monitored for runoff but which produced a debris flow (CB2), shed light on the mechanisms of shallow flow in bedrock, its interaction with the vadose zone, and its role in generating landslides. Previous work at CB1 led to the proposal that during storms pulses of rainfall transmit pressure waves through the vadose zone and down to the saturated zone to create rapid pore pressure response and runoff [, 1998]. Here, we document the associated rapid pore pressure response in the shallow fractured bedrock that underlies these colluvium-mantled sites and examine its influence on the generation of storm flow, seasonal variations in base flow, and slope stability in the overlying colluvial soil. Our observations document rapid piezometric response in the shallow bedrock and a substantial contribution of shallow fracture flow to both storm flow and seasonal variations in base flow. Saturated hydraulic conductivity in the colluvial soil decreases with depth below the ground surface, but the conductivity of the near-surface bedrock displays no depth dependence and varies over five orders of magnitude. Analysis of runoff intensity and duration in a series of storms that did and did not trigger debris flows in the surrounding area shows that the landslide inducing storms had the greatest intensity over durations similar to those predicted by a simple model of piezometric response. During a monitored storm in February 1992, the channel head at the base of the neighboring CB2 site failed as a debris flow. Automated piezometric measurements document that the CB2 debris flow initiated several hours after peak discharge, coincident with localized development of upward spikes of pressure head from near-surface bedrock into the overlying colluvial soil in CB1. Artesian flow observed exfiltrating from bedrock fractures on the failure surfaces

  7. Carbon and nitrogen dynamics across a bedrock-regulated subarctic pH gradient

    Science.gov (United States)

    Tomczyk, N.; Heim, E. W.; Sadowsky, J.; Remiszewski, K.; Varner, R. K.; Bryce, J. G.; Frey, S. D.

    2014-12-01

    Bedrock geochemistry has been shown to influence landscape evolution due to nutrient limitation on primary production. There may also be less direct interactions between bedrock-derived chemicals and ecosystem function. Effects of calcium (Ca) and pH on soil carbon (C) and nitrogen (N) cycling have been shown in acid impacted forests o f North America. Understanding intrinsic factors that affect C and nutrient dynamics in subarctic ecosystems has implications for how these ecosystems will respond to a changing climate. How the soil microbial community allocates enzymes to acquire resources from the environment can indicate whether a system is nutrient or energy limited. This study examined whether bedrock geochemistry exerts pressure on nutrient cycles in the overlying soils. In thin, weakly developed soils, bedrock is the primary mineral material and is a source of vital nutrients. Nitrogen (N) and C are not derived from bedrock, but their cycling is still affected by reactions with geologically-derived chemicals. Our study sites near Abisko, Sweden (~68°N) were selected adjacent to five distinct bedrock outcrops (quartzite, slate, carbonate, and two different metasedimenty units). All sites were at a similar elevation (~700 m a.s.l.) and had similar vegetation (subarctic heath). Nutrient concentrations in bedrock and soils were measured in addition to soil microbial biomass and extracellular enzyme activity. We found a statistically significant correlation between soil Ca concentrations and soil pH (r = 0.88, p < 0.01). There were also significant relationships between soil pH and the ratio of C-acquiring to N-acquiring enzyme activity (r = -0.89, p < 0.01), soil pH and soil C-to-N ratio (r = -0.76, p < 0.01), and the ratio of C-acquiring to N-acquiring enzyme activity and soil C-to-N ratio (r = 0.78, p < 0.01). These results suggest that soil Ca concentrations influence C and N cycling dynamics in these soils through their effect on soil pH.

  8. How does sediment affect the hydraulics of bedrock-alluvial rivers?

    Science.gov (United States)

    Hodge, Rebecca; Hoey, Trevor; Maniatis, George; Leprêtre, Emilie

    2016-04-01

    Relationships between flow, sediment transport and channel morphology are relatively well established in coarse-grained alluvial channels. Developing equivalent relationships for bedrock-alluvial channels is complicated by the two different components that comprise the channel morphology: bedrock and sediment. These two components usually have very different response times to hydraulic forcing, meaning that the bedrock morphology may be inherited from previous conditions. The influence of changing sediment cover on channel morphology and roughness will depend on the relative magnitudes of the sediment size and the spatial variations in bedrock elevation. We report results from experiments in a 0.9m wide flume designed to quantify the interactions between flow and sediment patch morphology using two contrasting bedrock topographies. The first topography is a plane bed with sand-scale roughness, and the second is a 1:10 scale, 3D printed, model of a bedrock channel with spatially variable roughness (standard deviation of elevations = 12 mm in the flume). In all experiments, a sediment pulse was added to the flume (D50 between 7 and 15 mm) and sediment patches were allowed to stabilise under constant flow conditions. The flow was then incrementally increased in order to identify the discharges at which sediment patches and isolated grains were eroded. In the plane bed experiments ˜20% sediment cover is sufficient to alter the channel hydraulics through the increased roughness of the bed; this impact is expressed as the increased discharge at which isolated grains are entrained. In the scaled bed experiments, partial sediment cover decreased local flow velocities on a relatively smooth area of the bed. At the scale of the entire channel, the bed morphology, and the hydraulics induced by it, was a primary control on sediment cover stability at lower sediment inputs. At higher inputs, where sediment infilled the local bed topography, patches were relatively more stable

  9. Mapping the geophysical bedrock of the Moesian Platform using H/V ratios and borehole data.

    Science.gov (United States)

    Florinela Manea, Elena; Michel, Clotaire; Fäh, Donat; Ortanza Cioflan, Carmen

    2016-04-01

    The strong effects at long periods observed in the extra-Carpathian area of Romania during large Vrancea intermediate-depth earthquakes were explained by the influence of both source mechanism and mechanical properties of the geological structure. Complex basin geometry and the low seismic velocities of the sediments are the primary responsible for the large amplification and long duration of the seismic records from the extra-Carpathian area during intermediate-depth earthquakes. The aim of this study is to map the geophysical bedrock of this area correlating and interpolating the results obtained from local resonance phenomena evaluation with the available surface geological data. The site was investigated through the computation of H/V spectral ratios from three-directional single station measurements of ambient vibration. The first step was to estimate the depth of the geophysical bedrock at all the Romanian seismic stations located in the extra-Carpathian area (velocity sensors) using the fundamental frequency retrieved from the H/V curves. In the second stage of the study all the relevant peaks from the H/V curves were interpreted in consonance with the available information of the geology. The geological data were obtained from the database developed in the national BIGSEES project by National Institute of Earth Physics. In this database are integrated all the geological, geophysical data from all the past projects, contracts, studies (as refraction, reflexion, etc.), geotechnical drillings and other information publicly available. The mapping of the geophysical bedrock was done interpolating the geological database and information gathered/resulted from H/V using a geographical informational system(GIS). The geology of this area displays very complex features as outcrops in small zones/lines/ near the Danube and then is gradually dipping to about 2 km depth in the N-NE. The depth of the bedrock is (nearly) constant around 100 m depth on the right side of

  10. The Salzach Valley overdeeping: A most precise bedrock model of a major alpine glacial basin

    Science.gov (United States)

    Pomper, Johannes; Salcher, Bernhard; Eichkitz, Christoph

    2016-04-01

    Overdeepenings are impressive phenomena related to the erosion in the ablation zone of major glaciers. They are common features in glaciated and deglaciated regions worldwide and their sedimentary fillings may act as important archives for regional environmental change and glaciation history. Sedimentary fillings are also important targets of geotechnical exploration and construction including groundwater resource management, shallow geothermal exploitation, tunneling and the foundation of buildings. This is especially true in densely populated areas such as the European Alps and their foreland areas, regions which have been multiply glaciated during the last million years. However, due depths often exceeding some hundreds of meters, the overall knowledge on their geometry, formation and sedimentary content is still poor and commonly tied to some local spots. Here we present a bedrock model of the overall lower Salzach Valley, one of the largest glacial overdeepings in the European Alps. We utilized seismic sections from hydrocarbon exploration surveys and deep drillings together with topographic and modelling data to construct a 3D bedrock model. Through the existence of seismic inline and crossline valley sections, multiple drillings reaching the bedrock surface, log and abundant outcrop data we were, as far to our knowledge, able to create the most accurate digital bedrock topography of an alpine major overdeepening. We furthermore analyzed the sedimentary content of the valley as recorded by driller's lithologic logs. Our results suggest that the valley is far from being a regular U-shaped trough with constant depth, rather highlighting highs and lows of different magnitude and underground valley widths of variable extent. Data also indicates that the largest overdeepening of bedrock, reaching around 450 m below the alluvial fill, is not situated after a major glacial confluence following a prominent bedrock gorge but shifted several km down the valley. The

  11. Organic Carbon Stabilization of Soils Formed on Acidic and Calcareous Bedrocks in Neotropical Alpine Grassland, Peru

    Science.gov (United States)

    Yang, Songyu; Cammeraat, Erik; Jansen, Boris; Cerli, Chiara; Kalbitz, Karsten

    2016-04-01

    Increasing evidence shows that Neotropical alpine ecosystems are vulnerable to global change. Since soils in the alpine grasslands of the Peruvian Andean region have large soil organic carbon (SOC) stocks, profound understanding of soil organic matter (OM) stabilization mechanisms will improve the prediction of the feedback between SOC stocks and global change. It is well documented that poor-crystalline minerals and organo-metallic complexes significantly contribute to the OM stabilization in volcanic ash soils, including those in the Andean region. However, limited research has focused on non-ash soils that also express significant SOC accumulation. A pilot study of Peruvian Andean grassland soils suggests that lithology is a prominent factor for such carbon accumulation. As a consequence of contrasting mineral composition and pedogenic processes in soils formed on different non-volcanic parent materials, differences in OM stabilization mechanisms may be profound and consequently may respond differently to global change. Therefore, our study aims at a further understanding of carbon stocks and OM stabilization mechanisms in soils formed on contrasting bedrocks in the Peruvian Andes. The main objective is to identify and compare the roles that organo-mineral associations and aggregations play in OM stabilization, by a combination of selective extraction methods and fractionations based on density, particle size and aggregates size. Soil samples were collected from igneous acidic and calcareous sedimentary bedrocks in alpine grassland near Cajamarca, Peru (7.17°S, 78.63°W), at around 3700m altitude. Samples were taken from 3 plots per bedrock type by sampling distinguishable horizons until the C horizons were reached. Outcomes confirmed that both types of soil accumulate large amounts of carbon: 405.3±41.7 t/ha of calcareous bedrock soil and 226.0±5.6 t/ha of acidic bedrock soil respectively. In addition, extremely high carbon contents exceeding 90g carbon per

  12. Final disposal of spent nuclear fuel in Finnish bedrock - Romuvaara site report

    Energy Technology Data Exchange (ETDEWEB)

    Anttila, P. [Fortum Engineering Oy (Finland); Ahokas, H. [Fintact Oy (Finland); Front, K. [VTT Communities and Infrastructure, Espoo (Finland)] [and others

    1999-06-01

    Posiva Oy is studying the Finnish bedrock for the geological disposal of spent nuclear fuel. The study is based on the site selection research programme started originally in 1983. The programme is in accordance with the decision in principle by the Council of State in 1983 and aims at the selection of one site in 2000. Four sites, Haestholmen in Loviisa, Kivetty in Aeaenekoski, Olkiluoto in Eurajoki and Romuvaara in Kuhmo, have been studied in detail. This report summarises the results of the site investigations carried out at Romuvaara. The bedrock of Romuvaara belongs to the Archean basement complex, whose oldest parts date back over 2800 million years. The bedrock consists mainly of migmatitic banded gneisses (tonalite, leucotonalite and mica gneiss), which are cut by granodiorite and metadiabase dykes. The rocks, excluding the metadiabase, have undergone a polyphase Archaean deformation. Altogether 31 bedrock structures (R-structures) have been modelled at the investigation site, most of them representing steeply dipping fracture zones. The rock mass between the fracture zones represents what is termed `intact rock`, which is typically hard, unweathered and sparsely fractured. The R-structures are generally hydraulically more conductive than the intact rock and their mean transmissivity is 1.6 x 10{sup -7} m{sup 2}/s. The corresponding mean of the hydraulic conductivity values for the intact rock measured using a 2 m packer interval is 8 x 10{sup -12} m/s, if a lognormal distribution for all measured values is assumed. A clear decrease in hydraulic conductivity with depth has been found, for both the R-structures and the intact rock. In addition, the hydraulically conductive fractures seem to be more frequent and their transmissivities higher in the uppermost 100 - 200 m of the bedrock than at greater depths. The groundwater of Romuvaara is classified as fresh water and the Total Dissolved Solids (TDS) and chloride contents increase with depth. The chemically

  13. An investigation into the bedrock depth in the Eskisehir Quaternary Basin (Turkey) using the microtremor method

    Science.gov (United States)

    Tün, M.; Pekkan, E.; Özel, O.; Guney, Y.

    2016-10-01

    Amplification can occur in a graben as a result of strong earthquake-induced ground motion. Thus, in seismic hazard and seismic site response studies, it is of the utmost importance to determine the geometry of the bedrock depth. The main objectives of this study were to determine the bedrock depth and map the depth-to-bedrock ratio for use in land use planning in regard to the mitigation of earthquake hazards in the Eskişehir Basin. The fundamental resonance frequencies (fr) of 318 investigation sites in the Eskişehir Basin were determined through case studies, and the 2-D S-wave velocity structure down to the bedrock depth was explored. Single-station microtremor data were collected from the 318 sites, as well as microtremor array data from nine sites, seismic reflection data from six sites, deep-drilling log data from three sites and shallow drilling log data from ten sites in the Eskişehir Graben. The fundamental resonance frequencies of the Eskişehir Basin sites were obtained from the microtremor data using the horizontal-to vertical (H/V) spectral ratio (HVSR) method. The phase velocities of the Rayleigh waves were estimated from the microtremor data using the spatial autocorrelation (SPAC) method. The fundamental resonance frequency range at the deepest point of the Eskişehir Basin was found to be 0.23-0.35 Hz. Based on the microtremor array measurements and the 2-D S-wave velocity profiles obtained using the SPAC method, a bedrock level with an average velocity of 1300 m s-1 was accepted as the bedrock depth limit in the region. The log data from a deep borehole and a seismic reflection cross-section of the basement rocks of the Eskişehir Basin were obtained and permitted a comparison of bedrock levels. Tests carried out using a multichannel walk-away technique permitted a seismic reflection cross-section to be obtained up to a depth of 1500-2000 m using an explosive energy source. The relationship between the fundamental resonance frequency in the

  14. DECIPHERING THE FINEST IMPRINT OF GLACIAL EROSION: OBJECTIVE ANALYSIS OF STRIAE PATTERNS ON BEDROCK

    Directory of Open Access Journals (Sweden)

    Piet Stroeven

    2011-05-01

    Full Text Available The aim of this study is to compare the efficiency of different mathematical and statistical geometrical methods applied to characterise the orientation distribution of striae on bedrock for deciphering the finest imprint of glacial erosion. The involved methods include automatic image analysis techniques of Fast Fourier Transform (FFT, and the experimental investigations by means of Saltikov's directed secants analysis (rose of intersection densities, applied to digital and analogue images of the striae pattern, respectively. In addition, the experimental data were compared with the modelling results made on the basis of Underwood's concept of linear systems in a plane. The experimental and modelling approaches in the framework of stereology yield consistent results. These results reveal that stereological methods allow a reliable and efficient delineation of different families of glacial striae from a complex record imprinted in bedrock.

  15. Preliminary Assessment of Water Levels in Bedrock Wells in New Hampshire, 1984 to 2007

    Science.gov (United States)

    Ayotte, Joseph D.; Kernen, Brandon M.; Wunsch, David R.; Argue, Denise M.; Bennett, Derek S.; Mack, Thomas J.

    2010-01-01

    Analysis of nearly 60,000 reported values of static water level (SWL, as depth below land surface) in bedrock wells in New Hampshire, aggregated on a yearly basis, showed an apparent deepening of SWL of about 13 ft (4 m) over the period 1984–2007. Water-level data were one-time measurements at each well and were analyzed, in part, to determine if they were suitable for analysis of trends in groundwater levels across the state. Other well characteristics, however, also have been changing over time, such as total well depth, casing length, the length of casing in bedrock, and to some extent, well yield. Analyses indicated that many of the well construction variables are significantly correlated; the apparent declines in water levels may have been caused by some of these factors. Information on changes in water use for the period was not available, although water use may be an important factor affecting water levels.

  16. Seasonally Moving Bedrock Block at Metsähovi, in Finland

    Science.gov (United States)

    Hokkanen, T.; Lehmuskoski, P.; Kaukolinna, J.

    2007-12-01

    1. INTRODUCTION According to the monthly levelling observations during four years in Southern Finland at Metsähovi the bedrock block has been found out to move vertically 3.5 mm. The levelling accuracy in such small area is better than 0.1 mm. The vertical displacement has a strong correlation with the temperature of bedrock and the displacement is more than 10 times larger than caused by the thermal expansion alone (Lehmuskoski, 2006). Horizontal movements of this block have not been observed within the measuring accuracy of 0.5 mm. The rock type of moving block is a micmatite granite and its cleavage is typically orthogonal. Mainly the study area is without soil cap, and only a minor part of it is under a thin till layer. We have studied the area in many ways e.g. leveling bolts, GPR, the temperature of bedrock, and a core sample to find out a reason for a movement. So far we have not got an unambiguous answer, but we have eliminated several options. 2. INVESTIGATIONS By measuring the positions of leveling bolts we mapped roughly the dimensions of moving block. Moreover, the study area is measured by GPR with 2 m grid to locate all fractures with low dipping. According to these studies we have located a rock block with approximate dimensions of 30 × 40 × 1 m. Because of strong temperature dependency of the displacement and the fact that the seasonal temperature variation of bedrock is a near surface phenomenon we can conclude that only a shallow part of bedrock is moving. A groundwater table is deeper than the bottom of a moving block and the displacement doesn't have any correlation with a precipitation with time lag or without it. Thus, we can ignore a possibility that hydrostatic pressure could lift a block for instance after rains. As the surface of bedrock is at its lowest position at a winter time neither the frost can be the source of lifting. We drilled five shallow holes to locate exactly the bottom of moving block and to get signs of thermal

  17. Measuring Flow Rate in Crystalline Bedrock Wells Using the Dissolved Oxygen Alteration Method.

    Science.gov (United States)

    Vitale, Sarah A; Robbins, Gary A

    2017-03-22

    Determination of vertical flow rates in a fractured bedrock well can aid in planning and implementing hydraulic tests, water quality sampling, and improving interpretations of water quality data. Although flowmeters are highly accurate in flow rate measurement, the high cost and logistics may be limiting. In this study the dissolved oxygen alteration method (DOAM) is expanded upon as a low-cost alternative to determine vertical flow rates in crystalline bedrock wells. The method entails altering the dissolved oxygen content in the wellbore through bubbler aeration, and monitoring the vertical advective movement of the dissolved oxygen over time. Measurements were taken for upward and downward flows, and under ambient and pumping conditions. Vertical flow rates from 0.06 to 2.30 Lpm were measured. To validate the method, flow rates determined with the DOAM were compared to pump discharge rates and found to be in agreement within 2.5%.

  18. Potential of groundwater contamination by polybrominated diphenyl ethers (PBDEs) in a sensitive bedrock aquifer (Canada)

    Science.gov (United States)

    Levison, Jana; Novakowski, Kent; Reiner, Eric J.; Kolic, Terry

    2012-03-01

    It is necessary to understand the presence, movement, and persistence of contaminants in aquifers to develop adequate groundwater protection plans. Fractured bedrock aquifers with thin overburden cover are very sensitive to contamination, and little is known about transport processes from the ground surface to depth in this setting. This study was undertaken to investigate the potential of groundwater contamination by polybrominated diphenyl ethers (PBDEs), which are flame retardants, in a natural fractured bedrock aquifer in Canada proven to be sensitive to contamination. PBDEs, which had not been previously measured in groundwater in detail, were detected in the study aquifer at concentrations greater than those observed in surface-water bodies. Potential sources include manure, septic tanks, and the atmosphere. From this scoping study, it is evident that additional surveys of PBDE concentrations in groundwater are warranted, especially in settings with high potential source concentrations coupled with sensitive aquifers.

  19. Bedrock geologic map of the Uxbridge quadrangle, Worcester County, Massachusetts, and Providence County, Rhode Island

    Science.gov (United States)

    Walsh, Gregory J.

    2014-01-01

    The bedrock geology of the 7.5-minute Uxbridge quadrangle consists of Neoproterozoic metamorphic and igneous rocks of the Avalon zone. In this area, rocks of the Avalon zone lie within the core of the Milford antiform, south and east of the terrane-bounding Bloody Bluff fault zone. Permian pegmatite dikes and quartz veins occur throughout the quadrangle. The oldest metasedimentary rocks include the Blackstone Group, which represents a Neoproterozoic peri-Gondwanan marginal shelf sequence. The metasedimentary rocks are intruded by Neoproterozoic arc-related plutonic rocks of the Rhode Island batholith. This report presents mapping by G.J. Walsh. The complete report consists of a map, text pamphlet, and GIS database. The map and text pamphlet are available only as downloadable files (see frame at right). The GIS database is available for download in ESRI™ shapefile and Google Earth™ formats, and includes contacts of bedrock geologic units, faults, outcrops, structural geologic information, geochemical data, and photographs.

  20. Autocyclic Formation, Retreat, and Destruction of Waterfalls in an Experimental Bedrock Channel

    Science.gov (United States)

    Scheingross, J. S.; Fuller, B. M.; Lamb, M. P.

    2015-12-01

    Waterfalls are ubiquitous in steep landscapes and have been documented to retreat upstream at rates far outpacing standard fluvial incision into bedrock. While the formation of waterfalls following changes in climate and base-level lowering have been well-documented, little work has explored the formation of waterfalls via the internal dynamics from interacting flow hydraulics, sediment flux, and evolving channel morphology. Distinguishing between waterfalls formed via external versus internal forcing is important, as waterfall formation and retreat rate is often applied in inverse to determine the timing of external forcing. Here, we present results from a laboratory experiment designed to explore channel incision and waterfall formation. We fed water and sediment at constant rates over an initially planar surface at 19.5% slope. A channel rapidly incised into the artificial bedrock substrate, and small-wavelength variations in erosion rate created steps and pools which grew in amplitude. As pools deepened, erosion was focused on the upstream pool faces creating steep segments in the channel bed. At the topographic breaks between these steep segments and their upstream treads, water detached from the bed forming ventilated waterfall jets which impacted the plunge pools below. Continued pool deepening led to sediment deposition on the pool floors, locally inhibiting vertical incision while the upstream and downstream surfaces were free to erode. Amplified erosion at the waterfall lip incised a new pool into the bedrock previously composing the waterfall face while simultaneous lowering of the downstream pool lip resulted in the destruction of the original pool. Repetition of this process in our experiment suggests that interactions between bedrock erosion and sediment cover can result in the formation of a series of plunge pools which retreat upstream, and that care must be taken to distinguish between autocyclic versus allocyclic waterfall formation in studies

  1. Waterfall formation driven by interacting flow hydraulics, sediment cover, and erosion in an experimental bedrock canyon

    Science.gov (United States)

    Scheingross, Joel; Lamb, Michael; Fuller, Brian

    2016-04-01

    Waterfalls are ubiquitous in steep landscapes and have been documented to retreat upstream at rates far outpacing standard fluvial incision into bedrock. While the formation of waterfalls following changes in climate and base-level lowering have been well-documented, little work has explored the formation of waterfalls via the internal dynamics from interacting flow hydraulics, sediment flux, and evolving channel morphology. Distinguishing between waterfalls formed via external versus internal forcing is important, as waterfall formation and retreat rate is often applied in inverse to determine the timing of external forcing. Here, we present results from a laboratory experiment designed to explore channel incision and waterfall formation. We fed water and sediment at constant rates over an initially planar surface tilted to 19.5% slope. A channel rapidly incised into the artificial bedrock substrate, and small-wavelength variations in erosion rate created steps and pools which grew in amplitude. As pools deepened, sediment cover at the downstream portion of pools locally limited erosion, while erosion in the upstream portion of the pool created steep faces. At the topographic breaks between these steep segments and their upstream treads, water detached from the bed forming ventilated waterfall jets which impacted the plunge pools below. Individual waterfalls were short-lived as pool-deepening promoted alluviation which prevented further pool-incision, while amplified erosion at the waterfall lip incised a new pool into the bedrock previously composing the waterfall face. Repetition of this process in our experiment suggests that interactions between bedrock erosion and sediment cover can result in the formation of a series of plunge pools which retreat upstream.

  2. Global distribution of bedrock exposures on Mars using THEMIS high-resolution thermal inertia

    Science.gov (United States)

    Edwards, C.S.; Bandfield, J.L.; Christensen, P.R.; Fergason, R.L.

    2009-01-01

    We investigate high thermal inertia surfaces using the Mars Odyssey Thermal Emission Imaging System (THEMIS) nighttime temperature images (100 m/pixel spatial sampling). For this study, we interpret any pixel in a THEMIS image with a thermal inertia over 1200 J m-2 K-1 s-1/2 as "bedrock" which represents either in situ rock exposures or rock-dominated surfaces. Three distinct morphologies, ranked from most to least common, are associated with these high thermal inertia surfaces: (1) valley and crater walls associated with mass wasting and high surface slope angles; (2) floors of craters with diameters >25 km and containing melt or volcanics associated with larger, high-energy impacts; and (3) intercrater surfaces with compositions significantly more mafic than the surrounding regolith. In general, bedrock instances on Mars occur as small exposures (less than several square kilometers) situated in lower-albedo (thermal inertia (>350 J m-2 K-1 s-1/2), and relatively dust-free (dust cover index <0.95) regions; however, there are instances that do not follow these generalizations. Most instances are concentrated in the southern highlands, with very few located at high latitudes (poleward of 45oN and 58oS), suggesting enhanced mechanical breakdown probably associated with permafrost. Overall, Mars has very little exposed bedrock with only 960 instances identified from 75oS to 75oN with likely <3500 km2 exposed, representing???1% of the total surface area. These data indicate that Mars has likely undergone large-scale surface processing and reworking, both chemically and mechanically, either destroying or masking a majority of the bedrock exposures on the planet. Copyright 2009 by the American Geophysical Union.

  3. The influence of bedrock hydrogeology on catchment-scale nitrate fate and transport in fractured aquifers.

    Science.gov (United States)

    Orr, Alison; Nitsche, Janka; Archbold, Marie; Deakin, Jenny; Ofterdinger, Ulrich; Flynn, Raymond

    2016-11-01

    Characterising catchment scale biogeochemical processes controlling nitrate fate in groundwater constitutes a fundamental consideration when applying programmes of measures to reduce risks posed by diffuse agricultural pollutants to water quality. Combining hydrochemical analyses with nitrate isotopic data and physical hydrogeological measurements permitted characterisation of biogeochemical processes influencing nitrogen fate and transport in the groundwater in two fractured bedrock aquifers with contrasting hydrogeology but comparable nutrient loads. Hydrochemical and isotopic analyses of groundwater samples collected from moderately fractured, diffusely karstified limestone indicated nitrification controlled dissolved nitrogen fate and delivery to aquatic receptors. By contrast nitrate concentrations in groundwater were considerably lower in a low transmissivity highly lithified sandstone and pyrite-bearing shale unit with patchy subsoil cover. Geophysical and hydrochemical investigations showed shallower intervals contained hydraulically active fractures where denitrification was reflected through lower nitrogen levels and an isotopic enrichment ratio of 1.7 between δ(15)N and δ(18)O. Study findings highlight the influence of bedrock hydrogeological conditions on aqueous nitrogen mobility. Investigation results demonstrate that bedrock conditions need to be considered when implementing catchment management plans to reduce the impact of agricultural practices on the quality of groundwater and baseflow in receiving rivers. Nitrate isotopic signatures in the groundwater of a freely draining catchment underlain by a karstified aquifer and a poorly draining aquifer with a low transmissivity aquifer.

  4. Characterisation of tree root penetration in bedrock and its impact on slope stability

    Science.gov (United States)

    Zhun, Mao; Selli, Lavinia; Guastini, Enrico; Preti, Federico

    2014-05-01

    The anchorage effect of tree root penetration in bedrock against shallow landslides has uniquely been discussed in conceptual models, but seldom been measured and characterised in fieldsite. Using both the ARBORADIX™ and the electrical resistivity tomography (ERT) techniques, we aims at (i) mapping the spatial distribution of tree roots penetrating in bedrock in situ, (ii) estimating their contributions to slope stabilization and (iii) comparing the two detection methods. The experimental site is located on Pomezzana (Lu), Tuscany Apennine, Italy, where a great shallow landslide occurred in 1996 following periods of intense precipitation events. On aslope of45°, the studied forest has a density of 1800 trees/ha, mainly composed of black alder Alnus glutinosa L. (95%). Root mapping was conducted in two plots close to each other: one within an intact zone with no landslide damage; the other within a restored zone since the landslide. In each plot, two repetitions were conducted in dense tree clusters and in gaps, respectively. Preliminary results showed that the density and spatial distribution of roots penetrating into bedrock were significantly associated to the site chronology (intact vs restored), stand density and tree positions. Thicker roots had much higher probability of penetrating into rocks. Each of detection methods showed it advantages and drawbacks. This study, highlighting the importance of the mechanical role of thick roots in slope stabilization, may significantly improve our understanding in the use of vegetation in ecological engineering.

  5. Geophysical logging of bedrock wells for geothermal gradient characterization in New Hampshire, 2013

    Science.gov (United States)

    Degnan, James R.; Barker, Gregory; Olson, Neil; Wilder, Leland

    2014-01-01

    The U.S. Geological Survey, in cooperation with the New Hampshire Geological Survey, measured the fluid temperature of groundwater and other geophysical properties in 10 bedrock wells in the State of New Hampshire in order to characterize geothermal gradients in bedrock. The wells selected for the study were deep (five ranging from 375 to 900 feet and five deeper than 900 feet) and 6 had low water yields, which correspond to low groundwater flow from fractures. This combination of depth and low water yield reduced the potential for flow-induced temperature changes that would mask the natural geothermal gradient in the bedrock. All the wells included in this study are privately owned, and permission to use the wells was obtained from landowners before geophysical logs were acquired for this study. National Institute of Standards and Technology thermistor readings were used to adjust the factory calibrated geophysical log data. A geometric correction to the gradient measurements was also necessary due to borehole deviation from vertical.

  6. Modeling early in situ wetting of a compacted bentonite buffer installed in low permeable crystalline bedrock

    Science.gov (United States)

    Dessirier, B.; Frampton, A.; Fransson, Å.; Jarsjö, J.

    2016-08-01

    The repository concept for geological disposal of spent nuclear fuel in Sweden and Finland is planned to be constructed in sparsely fractured crystalline bedrock and with an engineered bentonite buffer to embed the waste canisters. An important stage in such a deep repository is the postclosure phase following the deposition and the backfilling operations when the initially unsaturated buffer material gets hydrated by the groundwater delivered by the natural bedrock. We use numerical simulations to interpret observations on buffer wetting gathered during an in situ campaign, the Bentonite Rock Interaction Experiment, in which unsaturated bentonite columns were introduced into deposition holes in the floor of a 417 m deep tunnel at the Äspö Hard Rock Laboratory in Sweden. Our objectives are to assess the performance of state-of-the-art flow models in reproducing the buffer wetting process and to investigate to which extent dependable predictions of buffer wetting times and saturation patterns can be made based on information collected prior to buffer insertion. This would be important for preventing insertion into unsuitable bedrock environments. Field data and modeling results indicate the development of a de-saturated zone in the rock and show that in most cases, the presence or absence of fractures and flow heterogeneity are more important factors for correct wetting predictions than the total inflow. For instance, for an equal open-hole inflow value, homogeneous inflow yields much more rapid buffer wetting than cases where fractures are represented explicitly thus creating heterogeneous inflow distributions.

  7. Beneath it all: bedrock geology of the Catskill Mountains and implications of its weathering.

    Science.gov (United States)

    Ver Straeten, Charles A

    2013-09-01

    The Devonian-age bedrock of the Catskill Mountains has been the focus of many studies. This paper reviews the character and composition of the rocks of the Catskills, and examines weathering (rock decay) processes and their implications in the Catskills. Rocks of the Catskills and closest foothills consist of siliciclastic rocks (sandstones, mudrocks, conglomerates) with minimal, locally dispersed carbonate rocks. The former are dominated by quartz, metamorphic and sedimentary rock fragments, and clay minerals. Other minor sediment components include cements, authigenic and heavy minerals, and fossil organic matter. Physical, chemical, and biological weathering of the Catskill bedrock since uplift of the Appalachian region, combined with glaciation, have dissected a plateau of nearly horizontally layered rocks into a series of ridges, valleys, and peaks. The varied weathering processes, in conjunction with many factors (natural and anthropogenic), fragment the rocks, forming sediment and releasing various elements and compounds. These may have positive, neutral, or negative implications for the region's soils, waters, ecology, and human usage. A new generation of studies and analyses of the Catskill bedrock is needed to help answer a broad set of questions and problems across various fields of interest.

  8. Chemical weathering as a mechanism for the climatic control of bedrock river incision

    Science.gov (United States)

    Murphy, Brendan P.; Johnson, Joel P. L.; Gasparini, Nicole M.; Sklar, Leonard S.

    2016-04-01

    Feedbacks between climate, erosion and tectonics influence the rates of chemical weathering reactions, which can consume atmospheric CO2 and modulate global climate. However, quantitative predictions for the coupling of these feedbacks are limited because the specific mechanisms by which climate controls erosion are poorly understood. Here we show that climate-dependent chemical weathering controls the erodibility of bedrock-floored rivers across a rainfall gradient on the Big Island of Hawai‘i. Field data demonstrate that the physical strength of bedrock in streambeds varies with the degree of chemical weathering, which increases systematically with local rainfall rate. We find that incorporating the quantified relationships between local rainfall and erodibility into a commonly used river incision model is necessary to predict the rates and patterns of downcutting of these rivers. In contrast to using only precipitation-dependent river discharge to explain the climatic control of bedrock river incision, the mechanism of chemical weathering can explain strong coupling between local climate and river incision.

  9. Geology, Bedrock, Bedrock Geology of the Cary 7.5-minute Quadrangle, Published in 2001, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Field Observation information as of 2001. It is described as...

  10. Geology, Bedrock, Bedrock Geology of the Wake Forest 7.5-minute Quadrangle, Published in 2001, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2001. It is described as...

  11. Geology, Bedrock, Bedrock geologic map compilation of the west half of the Asheville 1:100,000 scale map., Published in 2006, 1:100000 (1in=8333ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:100000 (1in=8333ft) scale, was produced all or in part from Field Survey/GPS information as of 2006. It is described...

  12. Geology, Bedrock, Bedrock Geology of the Lake Wheeler 7.5-minute Quadrangle, Published in 1999, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Field Observation information as of 1999. It is described as...

  13. Geology, Bedrock, Bedrock Geology of the Apex 7.5-minute Quadrangle, Published in 2000, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Field Observation information as of 2000. It is described as...

  14. Modeling flow and sediment transport dynamics in the lowermost Mississippi River, Louisiana, USA, with an upstream alluvial-bedrock transition and a downstream bedrock-alluvial transition: Implications for land building using engineered diversions

    Science.gov (United States)

    Viparelli, Enrica; Nittrouer, Jeffrey A.; Parker, Gary

    2015-03-01

    The lowermost Mississippi River, defined herein as the river segment downstream of the Old River Control Structure and hydrodynamically influenced by the Gulf of Mexico, extends for approximately 500 km. This segment includes a bedrock (or more precisely, mixed bedrock-alluvial) reach that is bounded by an upstream alluvial-bedrock transition and a downstream bedrock-alluvial transition. Here we present a one-dimensional mathematical formulation for the long-term evolution of lowland rivers that is able to reproduce the morphodynamics of both the alluvial-bedrock and the bedrock-alluvial transitions. Model results show that the magnitude of the alluvial equilibrium bed slope relative to the bedrock surface slope and the depth of bedrock surface relative to the water surface base level strongly influence the mobile bed equilibrium of low-sloping river channels. Using data from the lowermost Mississippi River, the model is zeroed and validated at field scale by comparing the numerical results with field measurements. The model is then applied to predict the influence on the stability of channel bed elevation in response to delta restoration projects. In particular, the response of the river bed to the implementation of two examples of land-building diversions to extract water and sediment from the main channel is studied. In this regard, our model results show that engineered land-building diversions along the lowermost Mississippi River are capable of producing equilibrated bed profiles with only modest shoaling or erosion, and therefore, such diversions are a sustainable strategy for mitigating land loss within the Mississippi River Delta.

  15. Digital and preliminary bedrock geologic map of the Townshend 7.5 x 15 minute quadrangle, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-335A Armstrong, T.R., and Ratcliffe, N.M., 1998, Digital and preliminary bedrock geologic map of the Townshend 7.5 x 15 minute quadrangle,...

  16. Bedrock Geologic Map of the Southern Worcester Mountains Watershed, Middlesex and Stowe 7.5 minute quadrangles, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG2006-2 Gale, M.H., Kim, J., King, S., Montane, P., and Orsi, C., 2006, Bedrock Geologic Map of the Southern Worcester Mountains Watershed,...

  17. Digital and preliminary bedrock geologic map of the Vermont part of the Hartland quadrangle, Windsor County, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG98-123A Walsh, G. J., 1998, Digital and preliminary bedrock geologic map of the Vermont part of the Hartland quadrangle, Windsor County, Vermont:...

  18. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Bedrock Geology

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the area of bedrock geology types in square meters compiled for every catchment of MRB_E2RF1 catchments for Major River Basins...

  19. The effect of wet-dry weathering on the rate of bedrock river channel erosion by saltating gravel

    Science.gov (United States)

    Inoue, Takuya; Yamaguchi, Satomi; Nelson, Jonathan M.

    2017-01-01

    Previous work has shown that the bedrock erosion rate E because of collisions of saltating bedload can be expressed by E = βqb(1-Pc), where qb is the sediment transport rate, Pc is the extent of alluvial cover, and β is the abrasion coefficient. However, the dependence of the abrasion coefficient on the physical characteristics of the bedrock material is poorly known, and in particular, the effects of wet-dry weathering on the saltation-abrasion bedrock incision has not been specifically characterized. Observation suggests that the typical wet-dry cycling of exposed bedrock in river beds gives rise to cracks and voids that are likely to alter the incision rate of the material when subjected to impacts of moving sediment. In this study, flume experiments are performed to develop an understanding of how wet-dry cycling affects the rock tensile strength and the bedrock erosion rate. To represent the physical effects of weathering, boring cores taken from natural bedrock channel are exposed to artificial wet-dry cycles. The experimental results suggest the following: (1) the abrasion coefficient for fresh bedrock is estimated by β = 1.0 × 10− 4σT− 2(d/ksb)0.5, where σT is the tensile strength, d is the diameter of colliding gravel, and ksb is the hydraulic roughness height of bedrock; (2) the tensile strength of the bedrock decreases exponentially as a result of repeated wet-dry cycles, σT/σT0 = exp (-CTNWa0/σT0), where σT0 is the initial tensile strength, Wa0 is the initial normalized rate of water absorption., N is the number of wet-dry cycles, and CT is a constant; (3) the erosion rate of fresh bedrock depends on the inverse of the square of tensile strength, but the erosion rate of weathered bedrock depends on the − 1.5 power of tensile strength.

  20. Bedrock properties and glacial processes and landforms - some principles and examples

    Science.gov (United States)

    Krabbendam, M.

    2012-04-01

    The interpretation of glacial landforms is fundamental to the reconstruction of former ice-sheets, which in turn inform dynamic models of modern ice sheets. The leading concept of this presentation is that the morphology of (erosional) glacial landforms is controlled by: i) glacial processes, ii) the properties of the bedrock these processes act upon. Indirectly, bedrock properties may also influence subglacial processes themselves. Arguably, the effects of bedrock properties on glacial processes and resultant landforms have been somewhat neglected during the last decades. At first approximation the most relevant bedrock properties are intact rock strength and mass rock strength, for which Schmidt Hammer rebound values and joint spacing are reasonable (if non-ideal) proxies, that can be easily gathered in the field. Examples of the control or influence of bedrock properties on subglacial landforms and processes will be presented: • In NW Scotland, a palaeo-ice stream flowed at right angles over a sandstone/quartzite contact. The sandstone is relatively soft but thick-bedded with a wide joint spacing. Erosional bedforms suggest a high proportion of abrasion over plucking. The quartzite is hard but thin-bedded with narrow joint spacing. Erosional landforms are angular with abundant plucked faces, suggesting a high proportion of plucking over abrasion. Hardness and joint spacing thus exert a strong control on the dominantly operating subglacial erosional process and the resultant landforms [1, 2]. • Again in NW Scotland it is observed that in the transition from gneiss to sandstone, gneiss is barren with numerous rock basins (cnoc-an-lochan landscape), whilst the sandstone shows near-continuous till cover, composed of sandstone debris. This suggests that the gneiss/sandstone properties control rock basin formation (implication: lake abundance is not a reliable proxy for intensity of glacial erosion) but also the boundary between erosion and deposition beneath an

  1. Cable-suspended Ice and Bedrock Electromechanical Drill: Design and Tests

    Science.gov (United States)

    Wang, Rusheng; Talalay, Pavel; Sun, Youhong; Zheng, Zhichuan; Cao, Pinlu; Zhang, Nan; Chen, Chen; Xu, Huiwen; Xue, Hong; Xue, Jun; Yu, Dahui; Fan, Xiaopeng; Hu, Zhengyi; Yang, Cheng; Gong, Da; Liu, Chunpeng; Han, Junjie; Yu, Chengfeng; Hong, Jialing; Wang, Lili

    2014-05-01

    Directly obtaining the subglacial bedrock samples is one of the most important tasks of Antarctic exploration in the future, which has great significance to research the formation and evolution of the Antarctic ice sheet, research the environment at the junction of the ice and bedrock, and research the geologic structure in Polar Regions. To drill through ice and bedrock, a new modified version of the cable-suspended Ice and Bedrock Electromechanical Drill 'IBED' is designed. IBED drill has modulus construction. The upper part includes four sections: cable termination, slip rings section, antitorque system, electronic pressure chamber. The motor-gear system is differed by rotation speed of the output shaft of the gear-reducer. All modulus contain 3 kW AC3 × 380 V submersible motor. Gear-reducer for drilling in ice lowers the drill bit rotation speed to 100 rpm; gear reducer for subglacial drilling lowers the drill bit rotation speed to 500 rpm. In addition, module for dry core drilling contains vacuum pump for near bottom air reverse circulation instead of liquid-driven pump that is installed into other two variants. The rotation speed of air-driven pump is increased by the gear to 6000 rpm. In modules for drilling with liquid the gear pump is used with capacity of 38-41 L/min and maximal pressure of 0.2 MPa. IBED lower part for drilling in ice consists from two parts: chip chamber for filtration of drilling fluid and collecting chips, and core barrel with the drill bit. The outer/inner diameter of the ice core drill bit is 134/110 mm. Length of the core barrel is 2.5 m. Lower part of the bedrock drill is adapted for coring bedrock and contains standard 2-m length core barrel borrowed from conventional diamond drill string, chip chamber for gravity separation of rock cuttings and dead weights (appr. 200 kg) for increasing of the load on the diamond drill bit. The outer/inner diameters of the diamond bit are 59/41 mm. The IBED drill was tested in order to solve

  2. Quantitative extraction of bedrock exposed rate based on unmanned aerial vehicle data and TM image in Karst Environment

    Science.gov (United States)

    wang, hongyan; li, qiangzi; du, xin; zhao, longcai

    2016-04-01

    In the karst regions of Southwest China, rocky desertification is one of the most serious problems of land degradation. The bedrock exposed rate is one of the important indexes to assess the degree of rocky desertification in the karst regions. Because of the inherent merits of macro scale, frequency, efficiency and synthesis, remote sensing is the promising method to monitor and assess karst rocky desertification on large scale. However, the actual measurement of bedrock exposed rate is difficult and existing remote sensing methods cannot directly be exploited to extract the bedrock exposed rate owing to the high complexity and heterogeneity of karst environments. Therefore, based on the UAV and TM data, the paper selected Xingren County as the research area, and the quantitative extraction of the bedrock exposed rate based on the multi scale remote sensing data was developed. Firstly, we used the object oriented method to carry out the accurate classification of UAV image and based on the results of rock extraction, the bedrock exposed rate was calculated in the 30m grid scale. Parts of the calculated samples were as training data and another samples were as the model validation data. Secondly, in each grid the band reflectivity of TM data was extracted and we also calculated a variety of rock index and vegetation index (NDVI, SAVI etc.). Finally, the network model was established to extract the bedrock exposed rate, the correlation coefficient (R) of the network model was 0.855 and the correlation coefficient (R) of the validation model was 0.677, the root mean square error (RMSE) was 0.073. Based on the quantitative inversion model, the distribution map of the bedrock exposed rate in Xingren County was obtained. Keywords: Bedrock exposed rate, quantitative extraction, UAV and TM data, Karst rocky desertification.

  3. Revealing the unexplored fungal communities in deep groundwater of crystalline bedrock fracture zones in Olkiluoto, Finland.

    Science.gov (United States)

    Sohlberg, Elina; Bomberg, Malin; Miettinen, Hanna; Nyyssönen, Mari; Salavirta, Heikki; Vikman, Minna; Itävaara, Merja

    2015-01-01

    The diversity and functional role of fungi, one of the ecologically most important groups of eukaryotic microorganisms, remains largely unknown in deep biosphere environments. In this study we investigated fungal communities in packer-isolated bedrock fractures in Olkiluoto, Finland at depths ranging from 296 to 798 m below surface level. DNA- and cDNA-based high-throughput amplicon sequencing analysis of the fungal internal transcribed spacer (ITS) gene markers was used to examine the total fungal diversity and to identify the active members in deep fracture zones at different depths. Results showed that fungi were present in fracture zones at all depths and fungal diversity was higher than expected. Most of the observed fungal sequences belonged to the phylum Ascomycota. Phyla Basidiomycota and Chytridiomycota were only represented as a minor part of the fungal community. Dominating fungal classes in the deep bedrock aquifers were Sordariomycetes, Eurotiomycetes, and Dothideomycetes from the Ascomycota phylum and classes Microbotryomycetes and Tremellomycetes from the Basidiomycota phylum, which are the most frequently detected fungal taxa reported also from deep sea environments. In addition some fungal sequences represented potentially novel fungal species. Active fungi were detected in most of the fracture zones, which proves that fungi are able to maintain cellular activity in these oligotrophic conditions. Possible roles of fungi and their origin in deep bedrock groundwater can only be speculated in the light of current knowledge but some species may be specifically adapted to deep subsurface environment and may play important roles in the utilization and recycling of nutrients and thus sustaining the deep subsurface microbial community.

  4. Revealing the unexplored fungal communities in deep groundwater of crystalline bedrock fracture zones in Olkiluoto, Finland

    Directory of Open Access Journals (Sweden)

    Elina eSohlberg

    2015-06-01

    Full Text Available The diversity and functional role of fungi, one of the ecologically most important groups of eukaryotic microorganisms, remains largely unknown in deep biosphere environments. In this study we investigated fungal communities in packer-isolated bedrock fractures in Olkiluoto, Finland at depths ranging from 296 m to 798 m below surface level. DNA- and cDNA-based high-throughput amplicon sequencing analysis of the fungal internal transcribed spacer (ITS gene markers was used to examine the total fungal diversity and to identify the active members in deep fracture zones at different depths. Results showed that fungi were present in fracture zones at all depths and fungal diversity was higher than expected. Most of the observed fungal sequences belonged to the phylum Ascomycota. Phyla Basidiomycota and Chytridiomycota were only represented as a minor part of the fungal community. Dominating fungal classes in the deep bedrock aquifers were Sordariomycetes, Eurotiomycetes and Dothideomycetes from the Ascomycota phylum and classes Microbotryomycetes and Tremellomycetes from the Basidiomycota phylum, which are the most frequently detected fungal taxa reported also from deep sea environments. In addition some fungal sequences represented potentially novel fungal species. Active fungi were detected in most of the fracture zones, which proves that fungi are able to maintain cellular activity in these oligotrophic conditions. Possible roles of fungi and their origin in deep bedrock groundwater can only be speculated in the light of current knowledge but some species may be specifically adapted to deep subsurface environment and may play important roles in the utilization and recycling of nutrients and thus sustaining the deep subsurface microbial community.

  5. Quantitative morphology of bedrock fault surfaces and identification of paleo-earthquakes

    Science.gov (United States)

    He, Honglin; Wei, Zhanyu; Densmore, Alexander

    2016-12-01

    The quantitative analysis of morphologic characteristics of bedrock fault surfaces may be a useful approach to study faulting history and identify paleo-earthquakes. It is an effective complement to trenching techniques, especially to identify paleo-earthquakes in a bedrock area where trenching technique cannot be applied. In this paper, we calculate the 2D fractal dimension of three bedrock fault surfaces on the Huoshan piedmont fault in the Shanxi Graben, China using the isotropic empirical variogram. We show that the fractal dimension varies systematically with height above the base of the fault surface exposures, indicating a segmentation of the fault surface morphology. We interpret this segmentation as being due to different exposure duration of parallel fault surface bands, caused by periodical earthquakes, and discontinuous weathering. We take the average of fractal dimensions of each band as a characteristic value to describe its surface morphology, which can be used to estimate the exposure duration of the fault surface band and then the occurrence time of the earthquake that exposed the band. Combined with previous trenching results, we fit an empirical relationship between the exposure duration and the morphological characteristic value on the fault: D = 0.049 T + 2.246. The average width of those fault surface bands can also be regarded as an approximate vertical coseismic displacement of characteristic earthquake similar to the Hongdong M8 earthquake of 1303. Based on the segmentation of quantitative morphology of the three fault surfaces on the Huoshan piedmont fault, we identify three earthquake events. The coseismic vertical displacement of the characteristic earthquake on the Huoshan piedmont fault is estimated to be 3-4 m, the average width of these fault surface bands. Gaps with a width of 0.1-0.3 m between two adjacent bands, in which the fractal value increases gradually with fault surface height, are inferred to be caused by weathering

  6. Bedrock gorges in the central mainland Kachchh: Implications for landscape evolution

    Indian Academy of Sciences (India)

    M G Thakkar; B Goyal; A K Patidar; D M Maurya; L S Chamyal

    2006-04-01

    Kachchh possesses a fault-controlled first-order topography and several geomorphic features indicative of active tectonics.Though coseismic neotectonic activity is believed to be the major factor in the evolution of the landscape,detailed documentation and analysis of vital landscape features like drainage characteristics,bedrock gorges and terraces are lacking.The present study is a site-speci fic documentation of gorges developed in the central part of the mainland Kachchh.We analyzed and interpreted four gorges occurring on either side of Katrol Hill Fault (KHF).The Khari river gorge is endowed with six levels of bedrock terraces,some of which are studded with large potholes and flutings.Since no active development of potholes is observed along the rivers in the present day hyper-arid conditions,we infer an obvious linkage of gorges to the humid phases,which provided high energy runoff for the formation of gorges and distinct bedrock terraces and associated erosional features.Development of gorges within the miliolites and incision in the fluvial deposits to the south of the KHF indicates that the gorges were formed during Early Holocene.However,ubi-quitous occurrence of gorges along the streams to the south of KHF,the uniformly N40°E trend of the gorges,their close association with transverse faults and the short length of the exceptionally well developed Khari river gorge in the low-relief rocky plain to the north of KHF suggests an important role of neotectonic movements.

  7. Plucking in Mixed Alluvial-Bedrock Rivers: The Incipient Motion Problem

    Science.gov (United States)

    Hurst, A. A.; Furbish, D. J.

    2015-12-01

    Bedrock river channel erosion is an important factor in the evolution of landscapes, driving the relief of mountainous drainage basins and setting the lowest erosional positions of terrestrial landscapes. The mechanics behind erosional processes (predominantly plucking and abrasion) in these rivers are only recently being explored in depth. Plucking, the fracture and extraction of jointed blocks, is observationally an order of magnitude more efficient than abrasion, but if a river cannot provide the force necessary to move the plucked block, erosion by plucking cannot proceed. Therefore, incipient motion of blocks starting at rest on a solid surface is an important factor in erosion by plucking. Calculations of forces necessary for incipient motion require values of drag coefficients, which do not exist for bedrock contact geometry. We discovered from experiments on a flume that drag coefficients (CD) are inversely proportional to aspect ratios (RA), defined as the frontal block height to width. We used the relationship with field data from plucked blocks at a stream at Montgomery Bell State Park in Burns, TN, a mixed-alluvial bedrock channel with an actively incising knick zone, to support our theory and experimental data. Sizes of plucked blocks were compared to the velocities needed to move them, and then calculations done for bankfull velocities at the stream at Montgomery Bell to determine if it could attain these velocities. It was discovered that this stream has a bankfull depth-averaged velocity of 1.26 m s-1 and is capable of moving a large range of plucked block sizes. Therefore, erosion of this particular stream is plucking-limited, not transport-limited.

  8. Geochemical impacts of groundwater heat pump systems in an urban alluvial aquifer with evaporitic bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Garrido Schneider, Eduardo A. [Geological Survey of Spain (IGME), C/ Manuel Lasala no. 44, 9B, 50006 Zaragoza (Spain); García-Gil, Alejandro, E-mail: agargil@unizar.es [Department of Earth Sciences, University of Zaragoza, C/ Pedro Cerbuna 12, 50009 Zaragoza (Spain); GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18–26, 08034 Barcelona (Spain); Vázquez-Suñè, Enric [GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18–26, 08034 Barcelona (Spain); Sánchez-Navarro, José Á. [Department of Earth Sciences, University of Zaragoza, C/ Pedro Cerbuna 12, 50009 Zaragoza (Spain)

    2016-02-15

    In the last decade, there has been an extensive use of shallow geothermal exploitations in urban environments. Although the thermal interference between exploitations has been recently studied, there is a lack of knowledge regarding the geochemical impacts of those systems on the aquifers where they are installed. Groundwater flow line scale and well-doublet scale research work has been conducted at city scale to quantify the geochemical interaction of shallow geothermal exploitations with the environment. A comprehensive analysis was conducted on data obtained from a monitoring network specifically designed to control and develop aquifer policies related to thermal management of the aquifer. The geochemical impacts were evaluated from a thermodynamic point of view by means of saturation index (SI) calculations with respect to the different mineral species considered in the system. The results obtained indicate limited geochemical interaction with the urban environment in most of the situations. However, there are some cases where the interaction of the groundwater heat pump installations with the evaporitic bedrock resulted in the total disablement of the exploitation system operation wells. The application of the tool proposed proved to be pragmatic in the evaluation of geochemical impacts. Injection of water into the aquifer can trigger an important bedrock gypsum and halite dissolution process that is partly responsible for scaling in well casing pipes and collapse of the terrain in the vicinity of injection wells. - Highlights: • We studied geochemical impacts of groundwater heat pump systems. • We have sampled a monitoring network in an energetically exploited urban aquifer. • A limited geochemical interaction has been found in most of the exploitations. • Reinjection into the aquifer produces an important bedrock gypsum dissolution. • Scaling in well casing pipes and collapse of the terrain have been observed.

  9. Spatial variability in bank resistance to erosion on a large meandering, mixed bedrock-alluvial river

    Science.gov (United States)

    Konsoer, Kory M.; Rhoads, Bruce L.; Langendoen, Eddy J.; Best, James L.; Ursic, Mick E.; Abad, Jorge D.; Garcia, Marcelo H.

    2016-01-01

    Spatial heterogeneity in the erosion-resistance properties of the channel banks and floodplains associated with sediment characteristics, vegetation, or bedrock can have a substantial influence on the morphodynamics of meandering rivers, resulting in highly variable rates of bank erosion and complex patterns of planform evolution. Although past studies have examined the spatial variability in bank erodibility within small rivers, this aspect of the erosion-resistance properties for large rivers remains poorly understood. Furthermore, with the exception of recent numerical modeling that incorporates stochastic variability of floodplain erosional resistance, most models of meandering river dynamics have assumed uniform erodibility of the bank and floodplain materials. The present paper investigates the lateral and vertical heterogeneity in bank material properties and riparian vegetation within two elongate meander loops on a large mixed bedrock-alluvial river using several geotechnical field and laboratory methods. Additionally, the bank stability and toe-erosion numerical model (BSTEM) and repeat terrestrial LiDAR surveys are used to evaluate the capacity of the bank material properties to modify the rates and mechanisms of bank retreat. Results show that the textural properties of the bank materials, soil cohesion, and critical shear stress necessary for sediment entrainment differ substantially between the two bends and are also highly variable within each bend - laterally and vertically. Trees growing along the banks increase the resistance to erosion by contributing to the shear strength of the bank materials and are capable of increasing bank stability along a large river. Locally outcropping bedrock also influences bank erodibility in both bends. The results of this study demonstrate that spatial variability in the erosion-resistance properties of the channel banks is an important factor contributing to spatial variability in the rates and mechanisms of bank

  10. Bedrock nitrogen inputs support litter nitrogen fixation and temperate forest ecosystem fertility

    Science.gov (United States)

    Dynarski, K. A.; Mitchell, S. A.; Morford, S.; Houlton, B. Z.

    2015-12-01

    Nitrogen (N) is one of the most frequently limiting nutrients to terrestrial ecosystem productivity worldwide. As atmospheric carbon dioxide concentrations continue to rise, progressive N limitation is expected to constrain the ability of terrestrial ecosystems to store additional C, making an understanding of N inputs to terrestrial ecosystems increasingly important. In temperate forests, rock reservoirs and biological N fixation (BNF) represent two significant, but poorly characterized, inputs of bioavailable N. Recent research has demonstrated that bedrock can provide a substantial amount of ecosystem-available N in moderate-to-high relief areas with N-rich sedimentary bedrock. In these same ecosystems, asymbiotic BNF performed by heterotrophic microbes in plant litter can provide an additional N input of up to ~2 kg N ha-1 yr-1. Here, we tested the hypothesis that rock N inputs support increased litter BNF via enhanced ecosystem N fertility. We measured rates of BNF along with rock, soil, foliage, and litter chemistry across sites varying substantially in rock N concentrations (from 32 to 800 ppm N). The sites are dominated by Douglas fir and share similar climates and landscape positions (eroding slopes), yet display marked increases in foliar and soil N content as a function of rock N concentrations (foliar: R2=0.18, p<0.001, soil: R2=0.50, p=0.001). We found a significant positive correlation between rock N content and litter BNF rates (R2=0.11, p=0.0035), with rates of BNF at sites with greater than 400 ppm N in bedrock more than double rates of BNF at sites with lower than 400 ppm N in bedrock (p<0.001). These patterns could not be explained by increases in other rock-derived nutrients such as phosphorus or molybdenum, as neither of these known BNF controls increased over the rock N gradient. We found declining foliar lignin:N ratios with increased rock N, suggesting that rock N inputs can increase litter quality, supporting greater microbial activity

  11. Large water-table response to rainfall in a shallow bedrock aquifer having minimal overburden cover

    Science.gov (United States)

    Miles, Owen W.; Novakowski, Kent S.

    2016-10-01

    Rapid recharge events manifested as significant increases in hydraulic head have been observed in many fractured bedrock aquifers around the world. Often the response in hydraulic head exceeds what would be observed in an equivalent porous media by more than an order of magnitude. As the mechanisms that cause these events are poorly understood particularly under highly-transient conditions, a detailed investigation was conducted at a well-characterized field site in eastern Canada. During the spring and summer of 2012, frequent measurements of hydraulic head were obtained in gneissic terrain covered by a thin veneer of drift materials using 21 multi-level monitoring wells installed in the bedrock. Each of the wells was hydraulically tested from the water table to total depth using a straddle-packer system and fractures intersecting the wells were identified using a borehole camera prior to the construction of the multi-level piezometers. Rainfall and weather data were also collected over the same time period. A piezometer located on a bedrock outcrop which responded rapidly to rainfall was identified and used as a focus for numerical simulations. To determine the properties of the drift materials in the vicinity of the outcrop, a ground penetrating radar (GPR) survey was conducted over a 40 × 40 m area to map depth to bedrock and five in-situ permeameter tests were performed to estimate the hydraulic conductivity. Three-dimensional numerical simulations were conducted to reproduce the response in the piezometer for both short (24 h) and long (one month) timescales. The numerical simulations were used to determine what parameters have the greatest impact on controlling rapid recharge. Based on this study it was concluded that the large magnitude head rises recorded in this piezometer are a result of recharge to steeply inclined fractures exposed on or immediately adjacent to the outcrop. The hydraulic head responds rapidly because of the low specific yield of the

  12. Effect of tracer buoyancy on tracer experiments conducted in fractured crystalline bedrock

    Science.gov (United States)

    Becker, Matthew W.

    2003-02-01

    Tracer buoyancy has been shown to influence breakthrough from two-well tracer experiments conducted in porous media. Two-well tracer experiments are presented from fractured crystalline bedrock, in which the specific gravity of the tracer injectate varied from 1.0002 to 1.0133. Under the forced hydraulic conditions imposed, no difference in breakthrough was noted for the three experiments. These results show that even relatively dense tracer injectate solutions may have an insignificant effect on breakthrough when imposed gradients are sufficiently large.

  13. Quality of water from bedrock aquifers in the South Carolina Piedmont

    Science.gov (United States)

    Patterson, G.G.; Padgett, G.C.

    1984-01-01

    The geographic distributions of 12 common water-quality parameters of ground water from bedrock aquifers in the Piedmont physiographic province of South Carolina are presented in a series of maps. The maps are based on analyses by the South Carolina Department of Health and Environmental Control of water samples taken during the period 1972 to 1982 from 442 public and private wells developed in the Piedmont. In general, alkalinity, hardness, and concentrations of sodium, magnesium, and chloride were higher in the Carolina Slate Belt than they were in the other geologic belts of the Piedmont. (USGS)

  14. Bedrock geologic map of the Worcester South quadrangle, Worcester County, Massachusetts

    Science.gov (United States)

    Walsh, Gregory J.; Merschat, Arthur J.

    2015-09-29

    The bedrock geology of the 7.5-minute Worcester South quadrangle, Massachusetts, consists of deformed Neoproterozoic to Paleozoic crystalline metamorphic and intrusive igneous rocks in three fault-bounded terranes (zones), including the Avalon, Nashoba, and Merrimack zones (Zen and others, 1983). This quadrangle spans the easternmost occurrence of Ganderian margin arc-related rocks (Nashoba zone) in the southern New England part of the northern Appalachians, and coincides with the trailing edge of Ganderia (Merrimack and Nashoba zones) where it structurally overlies Avalonia (Hibbard and others, 2006; Pollock and others, 2012; van Staal and others, 2009, 2012).

  15. Practical estimates of field-saturated hydraulic conductivity of bedrock outcrops using a modified bottomless bucket method

    Science.gov (United States)

    Mirus, Benjamin B.; Perkins, Kim S.

    2012-01-01

    The bottomless bucket (BB) approach (Nimmo et al., 2009a) is a cost-effective method for rapidly characterizing field-saturated hydraulic conductivity Kfs of soils and alluvial deposits. This practical approach is of particular value for quantifying infiltration rates in remote areas with limited accessibility. A similar approach for bedrock outcrops is also of great value for improving quantitative understanding of infiltration and recharge in rugged terrain. We develop a simple modification to the BB method for application to bedrock outcrops, which uses a non-toxic, quick-drying silicone gel to seal the BB to the bedrock. These modifications to the field method require only minor changes to the analytical solution for calculating Kfs on soils. We investigate the reproducibility of the method with laboratory experiments on a previously studied calcarenite rock and conduct a sensitivity analysis to quantify uncertainty in our predictions. We apply the BB method on both bedrock and soil for sites on Pahute Mesa, which is located in a remote area of the Nevada National Security Site. The bedrock BB tests may require monitoring over several hours to days, depending on infiltration rates, which necessitates a cover to prevent evaporative losses. Our field and laboratory results compare well to Kfs values inferred from independent reports, which suggests the modified BB method can provide useful estimates and facilitate simple hypothesis testing. The ease with which the bedrock BB method can be deployed should facilitate more rapid in-situ data collection than is possible with alternative methods for quantitative characterization of infiltration into bedrock.

  16. Sediment transport through self-adjusting, bedrock-walled waterfall plunge pools

    Science.gov (United States)

    Scheingross, Joel S.; Lamb, Michael P.

    2016-05-01

    Many waterfalls have deep plunge pools that are often partially or fully filled with sediment. Sediment fill may control plunge-pool bedrock erosion rates, partially determine habitat availability for aquatic organisms, and affect sediment routing and debris flow initiation. Currently, there exists no mechanistic model to describe sediment transport through waterfall plunge pools. Here we develop an analytical model to predict steady-state plunge-pool depth and sediment-transport capacity by combining existing jet theory with sediment transport mechanics. Our model predicts plunge-pool sediment-transport capacity increases with increasing river discharge, flow velocity, and waterfall drop height and decreases with increasing plunge-pool depth, radius, and grain size. We tested the model using flume experiments under varying waterfall and plunge-pool geometries, flow hydraulics, and sediment size. The model and experiments show that through morphodynamic feedbacks, plunge pools aggrade to reach shallower equilibrium pool depths in response to increases in imposed sediment supply. Our theory for steady-state pool depth matches the experiments with an R2 value of 0.8, with discrepancies likely due to model simplifications of the hydraulics and sediment transport. Analysis of 75 waterfalls suggests that the water depths in natural plunge pools are strongly influenced by upstream sediment supply, and our model provides a mass-conserving framework to predict sediment and water storage in waterfall plunge pools for sediment routing, habitat assessment, and bedrock erosion modeling.

  17. Active Microbial Communities Inhabit Sulphate-Methane Interphase in Deep Bedrock Fracture Fluids in Olkiluoto, Finland

    Directory of Open Access Journals (Sweden)

    Malin Bomberg

    2015-01-01

    Full Text Available Active microbial communities of deep crystalline bedrock fracture water were investigated from seven different boreholes in Olkiluoto (Western Finland using bacterial and archaeal 16S rRNA, dsrB, and mcrA gene transcript targeted 454 pyrosequencing. Over a depth range of 296–798 m below ground surface the microbial communities changed according to depth, salinity gradient, and sulphate and methane concentrations. The highest bacterial diversity was observed in the sulphate-methane mixing zone (SMMZ at 250–350 m depth, whereas archaeal diversity was highest in the lowest boundaries of the SMMZ. Sulphide-oxidizing ε-proteobacteria (Sulfurimonas sp. dominated in the SMMZ and γ-proteobacteria (Pseudomonas spp. below the SMMZ. The active archaeal communities consisted mostly of ANME-2D and Thermoplasmatales groups, although Methermicoccaceae, Methanobacteriaceae, and Thermoplasmatales (SAGMEG, TMG were more common at 415–559 m depth. Typical indicator microorganisms for sulphate-methane transition zones in marine sediments, such as ANME-1 archaea, α-, β- and δ-proteobacteria, JS1, Actinomycetes, Planctomycetes, Chloroflexi, and MBGB Crenarchaeota were detected at specific depths. DsrB genes were most numerous and most actively transcribed in the SMMZ while the mcrA gene concentration was highest in the deep methane rich groundwater. Our results demonstrate that active and highly diverse but sparse and stratified microbial communities inhabit the Fennoscandian deep bedrock ecosystems.

  18. Active Microbial Communities Inhabit Sulphate-Methane Interphase in Deep Bedrock Fracture Fluids in Olkiluoto, Finland

    Science.gov (United States)

    Bomberg, Malin; Nyyssönen, Mari; Pitkänen, Petteri; Lehtinen, Anne; Itävaara, Merja

    2015-01-01

    Active microbial communities of deep crystalline bedrock fracture water were investigated from seven different boreholes in Olkiluoto (Western Finland) using bacterial and archaeal 16S rRNA, dsrB, and mcrA gene transcript targeted 454 pyrosequencing. Over a depth range of 296–798 m below ground surface the microbial communities changed according to depth, salinity gradient, and sulphate and methane concentrations. The highest bacterial diversity was observed in the sulphate-methane mixing zone (SMMZ) at 250–350 m depth, whereas archaeal diversity was highest in the lowest boundaries of the SMMZ. Sulphide-oxidizing ε-proteobacteria (Sulfurimonas sp.) dominated in the SMMZ and γ-proteobacteria (Pseudomonas spp.) below the SMMZ. The active archaeal communities consisted mostly of ANME-2D and Thermoplasmatales groups, although Methermicoccaceae, Methanobacteriaceae, and Thermoplasmatales (SAGMEG, TMG) were more common at 415–559 m depth. Typical indicator microorganisms for sulphate-methane transition zones in marine sediments, such as ANME-1 archaea, α-, β- and δ-proteobacteria, JS1, Actinomycetes, Planctomycetes, Chloroflexi, and MBGB Crenarchaeota were detected at specific depths. DsrB genes were most numerous and most actively transcribed in the SMMZ while the mcrA gene concentration was highest in the deep methane rich groundwater. Our results demonstrate that active and highly diverse but sparse and stratified microbial communities inhabit the Fennoscandian deep bedrock ecosystems. PMID:26425566

  19. Parameterization and quantification of recharge in crystalline fractured bedrocks in Galicia-Costa (NW Spain

    Directory of Open Access Journals (Sweden)

    J. R. Raposo

    2012-06-01

    Full Text Available Quantifying groundwater recharge in crystalline rocks presents great difficulties due to the high heterogeneity of the underground medium (mainly, due to heterogeneity in fracture network, which determines hydraulic parameters of the bedrock like hydraulic conductivity or effective porosity. Traditionally these rocks have been considered to have very low permeability, and their groundwater resources have usually been neglected; however, they can be of local importance when the bedrock presents a net of well-developed fractures. The current European Water Framework Directive requires an efficient management of all groundwater resources; this begins with a proper knowledge of the aquifer and accurate recharge estimation. In this study, an assessment of groundwater resources in the Spanish hydrologic district of Galicia-Costa, dominated by granitic and metasedimentary rocks, was carried out. A water-balance modeling approach was used for estimating recharge rates in nine pilot catchments representatives of both geologic materials. These results were cross-validated with an independent technique, i.e. the chloride mass balance (CMB. A relation among groundwater recharge and annual precipitation according to two different logistic curves was found for both granites and metasedimentary rocks, thus allowing the parameterization of recharge by means of only a few hydrogeological parameters. Total groundwater resources in Galicia-Costa were estimated to be 4427 hm3 yr−1. An analysis of spatial and temporal variability of recharge was also carried out.

  20. Geochemical impacts of groundwater heat pump systems in an urban alluvial aquifer with evaporitic bedrock.

    Science.gov (United States)

    Garrido Schneider, Eduardo A; García-Gil, Alejandro; Vázquez-Suñè, Enric; Sánchez-Navarro, José Á

    2016-02-15

    In the last decade, there has been an extensive use of shallow geothermal exploitations in urban environments. Although the thermal interference between exploitations has been recently studied, there is a lack of knowledge regarding the geochemical impacts of those systems on the aquifers where they are installed. Groundwater flow line scale and well-doublet scale research work has been conducted at city scale to quantify the geochemical interaction of shallow geothermal exploitations with the environment. A comprehensive analysis was conducted on data obtained from a monitoring network specifically designed to control and develop aquifer policies related to thermal management of the aquifer. The geochemical impacts were evaluated from a thermodynamic point of view by means of saturation index (SI) calculations with respect to the different mineral species considered in the system. The results obtained indicate limited geochemical interaction with the urban environment in most of the situations. However, there are some cases where the interaction of the groundwater heat pump installations with the evaporitic bedrock resulted in the total disablement of the exploitation system operation wells. The application of the tool proposed proved to be pragmatic in the evaluation of geochemical impacts. Injection of water into the aquifer can trigger an important bedrock gypsum and halite dissolution process that is partly responsible for scaling in well casing pipes and collapse of the terrain in the vicinity of injection wells.

  1. Cosmogenic 21Ne concentrations and exposure ages of summit bedrocks in the Grove Mountains,Antarctica

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Various sources of 21Ne and 22Ne exist in surface rocks:cosmogenic,in situ nucleogenic from internal U and Th,trapped crustal nucleogenic and trapped atmospheric.This paper reports the first measurement,in China,of cosmogenic 21Ne and 22Ne in surface bedrocks.We developed a unique sample pre-treatment procedure that effectively removed inclusions inside quartz grains,and thus maximally reduced nucleogenic contributions of 21Ne and 22Ne.Step-heating experiments show that concen-trations of cosmogenic 21Ne and 22Ne in summit bedrock samples R9202 and R9203 from Grove Mountains,Antarctica,are(3.83±0.87)×108 and(5.22±0.51)×108 atoms/g,respectively.The corresponding minimum exposure ages are 2.2±0.5 and 3.0±0.3 Ma.This indicates that the ice sheet in East Antarctica was uncovered the crest of Mount Harding,a typical nunatak in Grove Mountains,since at least mid-Pliocene.

  2. TORSIONAL VIBRATIONS OF A RIGID CIRCULAR PLATE ON SATURATED STRATUM OVERLAYING BEDROCK

    Institute of Scientific and Technical Information of China (English)

    CaiYuanqiang; WuDazhi; XuChangjie

    2005-01-01

    The torsional vibration of a rigid plate resting on saturated stratum overlaying bedrock has been analysed for the first time. The dynamic governing differential equations for saturated poroelastic medium are solved by employing the technology of Hankel transform. By taking into account the boundary conditions, the dual integral equations of torsional vibration of a rigid circular plate are established, which are further converted into a Fredholm integral equation of the second kind. Subsequently, the dynamic compliance coefficients of the foundation on saturated stratum, the contact shear stress under the foundation and the angular amplitude of the foundation are evaluated. Numerical results indicate that, when the dimensionless height is bigger than 5, saturated stratum overlaying bedrock can be treated as saturated half space approximately. When the dimensionless frequency is low, the permeability of the soil must be taken into account. Furthermore, when the vibration frequency is a constant, the height of the saturated stratum has a slight effect on the dimensionless contact shear stress under the foundation.

  3. An unsteady state tracer method for characterizing fractures in bedrock wells.

    Science.gov (United States)

    Libby, Jill L; Robbins, Gary A

    2014-01-01

    Evaluating contaminants impacting wells in fractured crystalline rock requires knowledge of the individual fractures contributing water. This typically involves using a sequence of tools including downhole geophysics, flow meters, and straddle packers. In conjunction with each other these methods are expensive, time consuming, and can be logistically difficult to implement. This study demonstrates an unsteady state tracer method as a cost-effective alternative for gathering fracture information in wells. The method entails introducing tracer dye throughout the well, inducing fracture flow into the well by conducting a slug test and then profiling the tracer concentration in the well to locate water contributing fractures where the dye has been diluted. By monitoring the development of the dilution zones within the wellbore with time, the transmissivity and the hydraulic head of the water contributing fractures can be determined. Ambient flow conditions and the contaminant concentration within the fractures can also be determined from the tracer dilution. This method was tested on a large physical model well and a bedrock well. The model well was used to test the theory underlying the method and to refine method logistics. The approach located the fracture and generated transmissivity values that were in excellent agreement with those calculated by slug testing. For the bedrock well tested, two major active fractures were located. Fracture location and ambient well conditions matched results from conventional methods. Estimates of transmissivity values by the tracer method were within an order of magnitude of those calculated using heat-pulse flow meter data.

  4. Bedrock geologic map of the Yucca Mountain area, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Day, W.C.; Potter, C.J.; Sweetkind, D.S.; Fridrich, C.J. [Geological Survey, Denver, CO (US); Dickerson, R.P.; San Juan, C.A.; Drake, R.M. II [Pacific Western Technologies, Inc., Denver, CO (US)

    1998-11-01

    Yucca Mountain, Nye County, Nevada, has been identified as a potential site for underground storage of high-level radioactive nuclear waste. Detailed bedrock geologic maps form an integral part of the site characterization program by providing the fundamental framework for research into the geologic hazards and hydrologic behavior of the mountain. This bedrock geologic map provides the geologic framework and structural setting for the area in and adjacent to the site of the potential repository. The study area comprises the northern and central parts of Yucca Mountain, located on the southern flank of the Timber Mountain-Oasis Valley caldera complex, which was the source for many of the volcanic units in the area. The Timber Mountain-Oasis Valley caldera complex is part of the Miocene southwestern Nevada volcanic field, which is within the Walker Lane belt. This tectonic belt is a northwest-striking megastructure lying between the more active Inyo-Mono and Basin-and-Range subsections o f the southwestern Great Basin.

  5. The role of weathering in the formation of bedrock valleys on Earth and Mars: A numerical modeling investigation

    Science.gov (United States)

    Pelletier, Jon D.; Baker, Victor R.

    2011-11-01

    Numerical models of bedrock valley development generally do not include weathering explicitly. Nevertheless, weathering is an essential process that acts in concert with the transport of loose debris by seepage and runoff to form many bedrock valleys. Here we propose a numerical model for bedrock valley development that explicitly distinguishes weathering and the transport of loose debris and is capable of forming bedrock valleys similar to those observed in nature. In the model, weathering rates are assumed to increase with increasing water availability, a relationship that data suggest likely applies in many water-limited environments. We compare and contrast the model results for cases in which weathering is the result of runoff-induced infiltration versus cases in which it is the result of seepage- or subsurface-driven flow. The surface flow-driven version of our model represents an alternative to the stream-power model that explicitly shows how rates of both weathering and the transport of loose debris are related to topography or water flow. The subsurface flow-driven version of our model can be solved analytically using the linearized Boussinesq approximation. In such cases the model predicts theater-headed valleys that are parabolic in planform, a prediction broadly consistent with the observed shapes of theater-headed bedrock valleys on Mars that have been attributed to a combination of seepage weathering and episodic removal of weathered debris by runoff, seepage, and/or spring discharge.

  6. Final disposal of spent nuclear fuel in Finnish bedrock. Haestholmen site report

    Energy Technology Data Exchange (ETDEWEB)

    Anttila, P. [Fortum Engineering Oy, Vantaa (Finland); Ahokas, H. [Fintact Oy, Helsinki (Finland); Front, K. [VTT Communities and Infrastructure, Espoo (Finland)

    1999-06-01

    Posiva Oy is studying the Finnish bedrock for the geological disposal of spent nuclear fuel. The study is based on the site selection research programme started originally in 1983. The programme is in accordance with the decision in principle by the Council of State in 1983 and aims at the selection of one site in 2000. Four sites, Haestholmen in Loviisa, Kivetty in Aeaenekoski, Olkiluoto in Eurajoki and Romuvaara in Kuhmo, have been studied in detail. This report summarises the results of the site investigations carried out at Haestholmen. The Haestholmen area is located within the anorogenic Wiborg rapakivi granite batholith, about 1630 million years in age, representing one of the youngest rock formations in Finland. Wiborgite, pyterlite, porphyritic rapakivi granite and even-grained rapakivi granite are the rock types present. 25 bedrock structures have been modelled at the site. Most of them are steeply-dipping fracture zones trending NW-SE and NE-SW, but several sub-horizontal zones, mainly dipping to the N-NE and the SW, are also present. The rock mass between the fracture zones represents what is termed `intact rock`, which is typically hard, unweathered and sparsely fractured. The bedrock structures are generally hydraulically more conductive than the intact rock and their mean transmissivity is 8 x 10{sup -6} m{sup 2}/s or 1.3 x 10{sup -6} m{sup 2}/s, depending on how structures are defined. The corresponding mean of the hydraulic conductivity values measured for the intact rock using a 2 m packer interval is 1 x 10{sup -12} m/s, if a lognormal distribution for all measured values is assumed. A clear decrease in hydraulic conductivity with depth has been found in the intact rock. In addition, the hydraulically conductive fractures seem to be more frequent and their transmissivities higher in the uppermost 100-200 m of the bedrock than at greater depths. The groundwater chemistry reflects the post-glacial history of the island of Haestholmen, which rose

  7. Final disposal of spent nuclear fuel in Finnish bedrock - Kivetty site report

    Energy Technology Data Exchange (ETDEWEB)

    Anttila, P. [Fortum Engineering Oy, Vantaa (Finland); Ahokas, H.; Front, K. [Fintact Oy (Finland)] [and others

    1999-06-01

    Posiva Oy is studying the Finnish bedrock for the geological disposal of spent nuclear fuel. The study is based on the site selection research programme started originally in 1983. The programme is in accordance with the decision in principle by the Council of State in 1983 and aims at the selection of one site in 2000. Four sites, Haestholmen in Loviisa, Kivetty in Aeaenekoski, Olkiluoto in Eurajoki and Romuvaara in Kuhmo, have been studied in detail. This report summarises the results of the site investigations carried out at Kivetty. The bedrock of Kivetty belongs to the large Svecofennian granitoid complex of central Finland, about 1880 million years in age. The most common rock type is porphyritic granodiorite, which is cut by younger medium-grained granodiorite and porphyritic or even-grained granite. Minor bodies of gabbro, older than the porphyritic granodiorite, are also present. The granitoids show evidence of two deformation phases. Altogether 29 bedrock 'structures' (R-structures) have been modelled at the investigation site, most of them representing steeply dipping fracture zones. The rock mass between the fracture zones represents what is termed 'intact rock', which is typically hard, unweathered and sparsely fractured. The R-structures are generally hydraulically more conductive than the intact rock and their mean transmissivity is 1.3-10{sup -6} m{sup 2}/s. The corresponding mean of the hydraulic conductivity values for the intact rock, measured using a 2 m packer interval is 4*10{sup -11} m{sup 2}/s, if a lognormal distribution for all measured values is assumed. A clear decrease in hydraulic conductivity with depth has been found for the intact rock, and there seems to be a parallel decrease in the transmissivity of structures. In addition, the hydraulically conductive fractures seem to be more frequent and their transmissivities higher in the uppermost 100 - 200 m of the bedrock than at greater depths. The groundwater of

  8. Final disposal of spent nuclear fuel in Finnish bedrock. Olkiluoto site report

    Energy Technology Data Exchange (ETDEWEB)

    Anttila, P. [Fortum Engineering Oy, Vantaa (Finland); Ahokas, H. [Fintact Oy, Helsinki (Finland); Front, K. [VTT Communication and Infrastructure, Espoo (Finland)] [and others

    1999-06-01

    Posiva Oy is studying the Finnish bedrock for the geological disposal of spent nuclear fuel. The study is based on the site selection research programme started originally in 1983. The programme is in accordance with the decision in principle by the Council of State in 1983 and aims at the selection of one site in 2000. Four sites, Haestholmen in Loviisa, Kivetty in Aeaenekoski, Olkiluoto in Eurajoki and Romuvaara in Kuhmo, have been studied in detail. This report summarises the results of the site investigations carried out at Olkiluoto. The bedrock of the Olkiluoto site consists of Svecofennian metasediments and platonic rocks, 1800-1900 million years in age. Migmatitic mica gneiss is the most abundant rock type, and is intruded by foliated tonalites and granodiorites and massive coarse-grained granites and pegmatites. Five successive plastic deformation phases have been defined. In total, 30 bedrock structures (R-structures) have been modelled at the site. Most of these represent steeply dipping fracture zones, but several sub-horizontal zones, gently dipping to the SE, have also been identified. The rock mass between the fracture zones represents what is termed `intact rock`, which is typically hard, unweathered and sparsely fractured. The R-structures are generally hydraulically more conductive than the intact rock and their mean transmissivity is 3 x 10{sup -7} m{sup 2}/s. The corresponding mean of the hydraulic conductivity values for the intact rock measured using a 2 m packer interval, is 8 x 10{sup -13} m/s, if a lognormal distribution for all measured values is assumed. A clear decrease in hydraulic conductivity with depth has been found for the intact rock, and there seems to be a parallel decrease in the transmissivity of structures. In addition, the hydraulically conductive fractures seem to be more frequent and their transmissivities higher in the uppermost 100 - 200 m of the bedrock than at greater depths. The groundwater chemistry reflects the

  9. Experimental Study of Bedrock Incision Processes by Both Suspended Load and Bedload Abrasions

    Science.gov (United States)

    Chatanantavet, P.; Whipple, K. X.; Adams, M. A.

    2010-12-01

    Channel incision into bedrock by both suspended load and bedload abrasions plays an important role in mountain landscape evolution. The study of erosion processes in both sediment transport regimes and their competition is therefore critical. Here we explored the dependence of experimental bedrock erosion rate on channel bed slope, water discharge, sediment flux, grain size, alluvial bed cover, and evolving channel morphology by slowly abrading weak concrete “bedrock.” In our flume, we are able to independently control bedload, suspended load, and water fluxes as well as channel slope. In the case of bedload, we also used a high-speed camera to track the saltation trajectories of coarse gravels on a smooth bed in another set of experiments and proposed new scaling relationships by including bed roughness and channel slope (separately from shear stress) for grain saltation velocity, height and length. In the case of bedload abrasion, we found that (1) all else held constant, erosion rate can (but not always) increase with channel slope in both smooth and rough bed conditions, (2) erosion rate increases with increasing grain size, and (3) erosion rate is insensitive to increasing water discharge. Thus shear stress is an inadequate metric for saltation dynamics and abrasion. In the case of suspended load abrasion, we found that (1) all else held constant, erosion occurred more in the planar bed condition than in the rough bed condition (deep grooves/slot canyons) because the erosion rate is strongly dependent on the near-bed flow (particle) velocity, (2) erosion rate increases with increasing sediment flux, and (3) perturbations (e.g., boulders) to the flow (thus creating turbulence/eddy) can greatly enhance the erosional efficiency. All else held constant (including bed morphology), the erosion rates by suspended load can account for 1.0 - 20 % (excluding the effect of flow perturbations) of those found in bedload erosion for the same sediment flux. Furthermore

  10. The hydraulics of a straight bedrock channel: Insights from solute dispersion studies

    Science.gov (United States)

    Richardson, Keith; Carling, Paul Anthony

    2006-12-01

    Bedrock channels represent a hydraulic environment quite different from that of alluvial channels, but currently, little is known about bedrock channel hydraulics and whether they differ in any fundamental sense from those of alluvial channels. A series of dye dilution experiments was carried out over a range of discharges in a straight reach of a bedrock channel (Birk Beck, U.K.), and an aggregated dead zone (ADZ) model for longitudinal solute transport and dispersion applied to the resulting time-concentration curves. The results of the experiments indicate the existence of two significant threshold discharges, Q1 and Q2. The dispersive fraction parameter of the ADZ model is found to decrease with increasing discharge, levelling off at a value close to zero for moderate to high discharges in excess of Q1. At these discharges, the flow behaves almost as plug flow with very little dispersion taking place. At high discharges (greater than Q2), the stage-discharge relationship deviates from a power law and discharge increases more slowly with increasing stage. In addition, area-weighted and momentum-weighted mean velocity values diverge strongly, as do estimates of reach volume derived from survey and from discharge and mean travel times. Celerity estimated from the slope of the stage-discharge relationship is found to peak at moderate discharges and to fall below momentum-weighted mean velocity estimates at a discharge equal to Q2. Two hypotheses, the Macroturbulent Mixing Hypothesis and the Decoupled Dead Zone Hypothesis, are advanced to account for these observations. The fall in dispersive fraction to near zero at discharges above Q1 is best explained as the result of a combination of increasing flow uniformity and effective lateral mixing across the whole channel cross section due to high turbulence intensities and large turbulent length scales. This means that potential dead zones in the bed and margins of the channel become well flushed and do not act as

  11. Fingerprinting TCE in a bedrock aquifer using compound-specific isotope analysis.

    Science.gov (United States)

    Lojkasek-Lima, Paulo; Aravena, Ramon; Parker, Beth L; Cherry, John A

    2012-01-01

    A dual isotope approach based on compound-specific isotope analysis (CSIA) of carbon (C) and chlorine (Cl) was used to identify sources of persistent trichloroethylene (TCE) that caused the shut-down in 1994 of a municipal well in an extensive fractured dolostone aquifer beneath Guelph, Ontario. Several nearby industrial properties have known subsurface TCE contamination; however, only one has created a comprehensive monitoring network in the bedrock. The impacted municipal well and many monitoring wells were sampled for volatile organic compounds (VOCs), inorganic parameters, and CSIA. A wide range in isotope values was observed at the study site. The TCE varies between -35.6‰ and -21.8‰ and from 1.6‰ to 3.2‰ for δ(13) C and δ(37) Cl, respectively. In case of cis-1,2-dichloroethene, the isotope values range between -36.3‰ and -18.9‰ and from 2.4‰ to 4.7‰ for δ(13) C and δ(37) Cl, respectively. The dual isotope approach represented by a plot of δ(13) C vs. δ(37) Cl shows the municipal well samples grouped in a domain clearly separate from all other samples from the property with the comprehensive well network. The CSIA results collected under non-pumping and short-term pumping conditions thus indicate that this particular property, which has been studied intensively for several years, is not a substantial contributor of the TCE presently in the municipal well under non-pumping conditions. This case study demonstrates that CSIA signatures would have been useful much earlier in the quest to examine sources of the TCE in the municipal well if bedrock monitoring wells had been located at several depths beneath each of the potential TCE-contributing properties. Moreover, the CSIA results show that microbial reductive dechlorination of TCE occurs in some parts of the bedrock aquifer. At this site, the use of CSIA for C and Cl in combination with analyses of VOC and redox parameters proved to be important due to the complexity introduced by

  12. Stratigraphic architecture of bedrock reference section, Victoria Crater, Meridiani Planum, Mars

    Science.gov (United States)

    Edgar, Lauren A.; Grotzinger, John P.; Hayes, Alex G.; Rubin, David M.; Squyres, Steve W.; Bell, James F.; Herkenhoff, Ken E.

    2012-01-01

    The Mars Exploration Rover Opportunity has investigated bedrock outcrops exposed in several craters at Meridiani Planum, Mars, in an effort to better understand the role of surface processes in its geologic history. Opportunity has recently completed its observations of Victoria crater, which is 750 m in diameter and exposes cliffs up to ~15 m high. The plains surrounding Victoria crater are ~10 m higher in elevation than those surrounding the previously explored Endurance crater, indicating that the Victoria crater exposes a stratigraphically higher section than does the Endurance crater; however, Victoria strata overlap in elevation with the rocks exposed at the Erebus crater. Victoria crater has a well-developed geomorphic pattern of promontories and embayments that define the crater wall and that reveal thick bedsets (3–7m) of large-scale cross-bedding, interpreted as fossil eolian dunes. Opportunity was able to drive into the crater at Duck Bay, located on the western margin of Victoria crater. Data from the Microscopic Imager and Panoramic Camera reveal details about the structures, textures, and depositional and diagenetic events that influenced the Victoria bedrock. A lithostratigraphic subdivision of bedrock units was enabled by the presence of a light-toned band that lines much of the upper rim of the crater. In ascending order, three stratigraphic units are named Lyell, Smith, and Steno; Smith is the light-toned band. In the Reference Section exposed along the ingress path at Duck Bay, Smith is interpreted to represent a zone of diagenetic recrystallization; however, its upper contact also coincides with a primary erosional surface. Elsewhere in the crater the diagenetic band crosscuts the physical stratigraphy. Correlation with strata present at nearby promontory Cape Verde indicates that there is an erosional surface at the base of the cliff face that corresponds to the erosional contact below Steno. The erosional contact at the base of Cape Verde

  13. Stratified basal diamicts and their implications for subglacial conditions in deeply incised bedrock troughs

    Science.gov (United States)

    Buechi, Marius W.; Menzies, John; Anselmetti, Flavio S.

    2016-04-01

    Deep bedrock troughs ("tunnel valleys"), formed below Pleistocene piedmont glaciers, serve as valuable archives of the Quaternary landscape evolution of the Northern Alpine foreland basin. The sedimentary infill of these troughs is often dominated by glacier retreat deposits (e.g. glacio-lacustrine silts), while the context of diamicts and gravels at the base, i.e. directly overlying bedrock, remain controversial with regard to their deposition in a subglacial or proglacial environment. We present results from a set of drill cores that recovered such coarse-grained basal units in a major buried bedrock-trough system in the Lower Glatt Valley, Northern Switzerland. The excellent core recovery has allowed a detailed lithological study combining macroscopic, microscopic and geochemical methods. The macroscopic analysis revealed that the basal infill comprises diamicts segmented into ~1-3 m thick layers by sorted interbeds. These interbeds consist either of i) clast-supported gravels interpreted as bedload or lag deposits, or ii) laminated sands and silts representing deposition dominated by low-energy settling. The thinly spaced stacking of sorted and stratified sediments results in a high vertical facies variability. The distinct changes in the energy levels at which the sorted interbeds were transported and deposited are interpreted to indicate alternating phases of a decoupled and coupled ice-bed-interface at the base of the overdeepening. This interpretation is supported by the microstructural analysis performed on thin-sections from diamictons of the basal unit, which reveal a polyphase (brittle and ductile) deformation of the diamicts. A primary indication for a subglacial origin of the deformation comes from an abundance of crushed grains, interpreted as resulting from in-situ fracturing of grains under high tensile stresses, typically attained at grain-to-grain contacts during subglacial deformation. Such a signature is unlikely to occur in a proglacial

  14. Bedrock displacements in Greenland manifest ice mass variations, climate cycles and climate change

    DEFF Research Database (Denmark)

    Bevis, Michael; Wahr, John; Khan, Shfaqat Abbas;

    2012-01-01

    The Greenland GPS Network (GNET) uses the Global Positioning System (GPS) to measure the displacement of bedrock exposed near the margins of the Greenland ice sheet. The entire network is uplifting in response to past and present-day changes in ice mass. Crustal displacement is largely accounted...... for by an annual oscillation superimposed on a sustained trend. The oscillation is driven by earth’s elastic response to seasonal variations in ice mass and air mass (i.e., atmospheric pressure). Observed vertical velocities are higher and often much higher than predicted rates of postglacial rebound (PGR......), implying that uplift is usually dominated by the solid earth’s instantaneous elastic response to contemporary losses in ice mass rather than PGR. Superimposed on longer-term trends, an anomalous ‘pulse’ of uplift accumulated at many GNET stations during an approximate six-month period in 2010...

  15. A review of published literature on the effects of permafrost on the hydrogeochemistry of bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Cascoyne, M. [Gascoyne GeoProjects Inc. (Canada)

    2000-06-01

    formed on freezing of seawater, enhanced or depleted sulphate concentrations in certain groundwaters, and lighter isotopic signature of the saline waters caused by the ice-water isotopic fractionation. This review has found that salt-rejection processes undoubtedly will have occurred in groundwaters in the marine sediments and bedrock of the Baltic coast during the Pleistocene. Deeply penetrating permafrost in the bedrock would cause relatively pure water to form as ice in fractures and displace residual saline fluids, under density flow, to greater depths. The process could have occurred to a sufficient extent that large volumes of saline water were generated, some of which may currently remain in the fractured rock. In these waters, loss of sulphate by mirabilite precipitation would be expected to have occurred but, on warming and degradation of the permafrost, lower-salinity meltwaters would re-dissolve the mirabilite, giving rise to a SO{sub 4}-rich groundwater. This may be the origin of groundwater that is currently identified as Litorina Sea water at the Aespoe and Olkiluoto sites. This mechanism differs from that suggested by Israeli workers who propose freezing of open seawater and infiltration of residual brines into the bedrock followed by lateral migration inland. The hypothesis presented here, of formation of saline waters and brines by permafrost aggradation and salt-rejection is more acceptable from a hydrogeological standpoint because the saline waters are formed in situ and need not migrate laterally. Further field evidence, coupled with modelling of depths of permafrost penetration, could be used to assess the volume and concentration of saline groundwater formed as a result of downward advancement of permafrost in the crystalline bedrock. (orig.)

  16. Stable isotope signatures of gases liberated from fluid inclusions in bedrock at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Eichinger, F. (Hydroisotop GmbH, Schweitenkirchen (DE)); Meier, D.; Haemmerli, J.; Diamond, L. (Bern Univ. (CH), RWI, Institute of Geological Sciences)

    2010-12-15

    Fluid inclusions in quartzes of the Olkiluoto bedrock contain gaseous N{sub 2}, CO{sub 2}, H{sub 2}, CH{sub 4}, and higher hydrocarbons in varying proportions. Stable carbon and hydrogen isotope signatures of the gas phases give valuable information on their origin and the formation conditions. In previous studies, a method to liberate and quantify the gases trapped in fluid inclusions was developed. It allowed determining the carbon isotope signatures of liberated CO{sub 2}, CH{sub 4} and higher hydrocarbons (HHC), but no hydrogen isotope data were acquired. The method was advanced and, in this study, also stable hydrogen isotopes of CH{sub 4} and H{sub 2} liberated from fluid inclusions could be analysed. The stable carbon signatures of methane and higher hydrocarbons, as well as the hydrogen isotope signatures of methane indicate a predominant thermogenic provenance for those gases. (orig.)

  17. Integrated Characterization of DNAPL Source Zone Architecture in Clay Till and Limestone Bedrock

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Janniche, Gry Sander; Fjordbøge, Annika Sidelmann;

    2014-01-01

    an improved conceptual understanding of DNAPL source zone architecture in fractured limestone. The DNAPL source zone architecture in the clay till was consistent with conceptual expectations. In contrast the documentation for and quantification of DNAPL in the limestone aquifer was limited and demands......Background/Objectives. Characterization of dense non-aqueous phase liquid (DNAPL) source zone architecture is essential to develop accurate site specific conceptual models, delineate and quantify contaminant mass, perform risk assessment, and select and design remediation alternatives....... The activities of a distribution facility for perchloroethene (PCE) and trichloroethene (TCE) at the Naverland site near Copenhagen, Denmark, has resulted in PCE and TCE DNAPL impacts to a fractured clay till and an underlying fractured limestone aquifer/bedrock. The scope of the investigations was to evaluate...

  18. The Relationship Among Bedrock Seismic Ground Motion Parameters with Different Exceedance Probabilities in the Panxi Area

    Institute of Scientific and Technical Information of China (English)

    Lei Jiancheng

    2003-01-01

    Based on the calculation of the bedrock effective peak acceleration (EPA) zoning map in the Panxi area, the ratios of EPA with exceedance probabilities of 63%, 5%, 3%, 2% and 1% over 50 years to that of 10% in 50 years are 0.302, 1.30, 1.55, 1.76 and 2.14, respectively. The seismic effect will be conservative and safe if taking this zoning map as the earthquake-resistant fortification level and following the relevant rules of the Code for Seismic Design of Buildings (GBJ11-89) to calculate the seismic effect. Furthermore, the main factors that influence the A10/A63 ratios have been found to be the attenuation relationship of seismic ground motion, the division of seismic potential source regions and the seismicity parameters. These achievements are helpful to the spreading and applying of the zoning map.

  19. Application of rock-cad modelling system in characterization of crystalline bedrock

    Science.gov (United States)

    Saksa, Pauli

    The Finnish power company Teollisuuden Voima Oy studies crystalline bedrock in Finland for final disposal of high-level nuclear fuel waste. In evaluation of the varying lithological and structural conditions CAD-based ROCK-CAD system has been developed. ROCK-CAD is based on true solid modelling approach. One modelled volume consists of several mutually independent submodels. Mainly lithological, structural (fracturing) and hydraulical properties are modelled. ROCK-CAD is in operational use and experiences have been got from four sites modelled this far. The main uses of the software, have been in general visualization, in planning of sopplementary investigations and in qualitative interpretation and model development done by the experts. Computerized models form also the basis for ground water flow simulations and rock mechanical calculations. Two example drawings are presented and discussed.

  20. Hydrogeochemistry and Origin of Thermal Groundwater in Bedrock Aquifers in Tianjin, China

    Institute of Scientific and Technical Information of China (English)

    Zhou Xun; Fang Bin; Shen Ye; Zhang Hua; Lin Li; Lin Jianwang

    2004-01-01

    Thermal groundwater resources were found to have occurred in deep-seated bedrock aquifers in the northeastern North China plain near Tianjin, China. Meso- to Neo-Proterozoic and Paleozoic carbonate rocks on the Cangxian uplift are capable of yielding 960-4 200 m3/d of 60 to 96 ℃ water from the wells ranging in depth between 1 000 and 4 000 m. Conductive heat flow of 0.063 to 0.144 2 W/m2 from the deep crust is responsible for this anomalous geothermal field. The water in the Ordovician aquifer is characterized by relatively high TDS, high concentrations of SO4 and SO4*Cl-Na*Ca type, but the waters from the Meso- to Neo-Proterozoic and Cambrian aquifers, by relatively low TDS, low concentrations of SO4 and predominantly Cl*SO4-Na type. It is noted that when the temperature of the waters increases at a rate of 10 ℃ in the range of 30-100 ℃, the content of SiO2 increases at a rate of 12 to 15 mg/L, and fluoride concentration increases at a rate of 2.3 to 2.5 mg/L. Hydrochemical and isotopic data suggest that the thermal water in the bedrock aquifers is of meteoric origin and recharged in the northern mountain area to the north of the Baodi-Ninghe fault, and then flows laterally for a long distance from the north to the south to the city of Tianjin. Temperature of the waters increases because of heat exchange with the rocks and recharge by conductive heat flow from beneath.

  1. Mineral deformation and subglacial processes on ice-bedrock interface of Hailuogou Glacier

    Institute of Scientific and Technical Information of China (English)

    LIU GengNian; CHEN YiXin; ZHANG Yue; FU HaiRong

    2009-01-01

    Hailuogou Glacier is located in a warm and humid maritime environment. It is large and moves very fast.The bottom of the glacier slides intensively and the temperature at the bottom approaches the pressure melting point. Therefore,there are abundant melting water and debris which act as effective "grinding tools"for glacial abrasion. Polarizing microscope is used to observe the mineral deformation characteristics on the ice-bedrock interface. It is found that feldspar,quartz,hornblende and biotite are exposed to deformation,fracture and chemical alteration to various extents. Bending deformation is common for biotite,due to their lattice characteristics,and the bending orientations are mostly the same as the glacier flow. Bending deformation also occurs in a few hornblendes. High-angle tension fracture and low-angle shear fracture are common for quartz and feldspar,some of them are totally crushed (mylonizations) due to their rigidity. Thus,all the abrasion,quarrying,subglacial water action and subglacial dissolution processes at the bottom of the glacier are verified at the micro-scale level.Mineral deformation and fracture are the basic subglacial erosion mechanisms. The abrasion thickness is 30-90 μm for each time and the average is 50 μm. Most of the debris are silt produced by glacial abrasion. The extent of mineral deformation and fracture decreases drastically downwards beneath the bedrock surface. The estimated erosion rate is about 2.2-11.4 mm/a,which is similar to that of other maritime alpine glaciers,smaller than that of large-scale piedmont glaciers In Alaska (10-30 mm/a),and larger than that of continental glaciers (0.1-1.0 mm/a). The type and size of a glacier are the main factors that influence its erosion rate.

  2. Noble gas residence times of saline waters within crystalline bedrock, Outokumpu Deep Drill Hole, Finland

    Science.gov (United States)

    Kietäväinen, Riikka; Ahonen, Lasse; Kukkonen, Ilmo T.; Niedermann, Samuel; Wiersberg, Thomas

    2014-11-01

    Noble gas residence times of saline groundwaters from the 2516 m deep Outokumpu Deep Drill Hole, located within the Precambrian crystalline bedrock of the Fennoscandian Shield in Finland, are presented. The accumulation of radiogenic (4He, 40Ar) and nucleogenic (21Ne) noble gas isotopes in situ together with the effects of diffusion are considered. Fluid samples were collected from depths between 180 and 2480 m below surface, allowing us to compare the modelled values with the measured concentrations along a vertical depth profile. The results show that while the concentrations in the upper part are likely affected by diffusion, there is no indication of diffusive loss at or below 500 m depth. Furthermore, no mantle derived gases were found unequivocally. Previous studies have shown that distinct vertical variation occurs both in geochemistry and microbial community structuring along the drill hole, indicating stagnant waters with no significant exchange of fluids between different fracture systems or with surface waters. Therefore in situ accumulation is the most plausible model for the determination of noble gas residence times. The results show that the saline groundwaters in Outokumpu are remarkably old, with most of the samples indicating residence times between ∼20 and 50 Ma. Although being first order approximations, the ages of the fluids clearly indicate that their formation must predate more recent events, such as Quaternary glaciations. Isolation within the crust since the Eocene-Miocene epochs has also direct implications to the deep biosphere found at Outokumpu. These ecosystems must have been isolated for a long time and thus very likely rely on energy and carbon sources such as H2 and CO2 from groundwater and adjacent bedrock rather than from the ground surface.

  3. DETECTION OF GROUNDWATER AGES WITH 85 KR IN ARSENIC-BEARING, FRACTURED CRYSTALLINE BEDROCK OF THE GOOSE RIVER BASIN, MAINE

    Science.gov (United States)

    Young groundwater from various depths in crystalline bedrock of the Goose River basin, mid-coastal Maine, is documented from 85Kr isotope age analyses (1963 ? 1987) but not from 3H isotope age analyses. Elevated geogenic arsenic in drinking water from groundwater wells and sprin...

  4. Hydraulic relationships between buried valley sediments of the glacial drift and adjacent bedrock formations in northeastern Ohio, USA

    Science.gov (United States)

    Seyoum, Wondwosen Mekonnen; Eckstein, Yoram

    2014-08-01

    Buried valleys are ancient river or stream valleys that predate the recent glaciation and since have been filled with glacial till and/or outwash. Outwash deposits are known to store and transmit large amounts of groundwater. In addition to their intrinsic hydraulic properties, their productivity depends on their hydraulic relationships with the adjacent bedrock formations. These relationships are examined using a steady-state three-dimensional groundwater flow model through a section of a buried valley in northeastern Ohio, USA. The flow domain was divided into five hydrostratigraphic units: low-conductivity (K) till, high-K outwash, and three bedrock units (Pottsville Formation, Cuyahoga Group and Berea Sandstone). The model input was prepared using the data from well logs and drilling reports of residential water wells. The model was calibrated using observed heads with mean residual head error of 0.3 m. The calibrated model was used to quantify flux between the buried valley and bedrock formations. Mass balance was calculated to within an error of 2-3 %. Mass balance of the buried valley layer indicates that it receives 1.6 Mm3/year (≈40 % of the total inflow) from the adjacent bedrock aquifers: Pottsville Formation contributes 0.96 Mm3/year (60 %) while the Berea Sandstone 0.64 Mm3/year (40 %).

  5. Study on safe thickness of overlying thin bedrock in fully-mechanized top-coal caving face with thick coal seam

    Institute of Scientific and Technical Information of China (English)

    FANG Xin-qiu; HUANG Han-fu; HE Jie

    2007-01-01

    To prevent support crush, the overlying strata safe thickness and its influential elements were studied by the adoption of theoretical analysis, numerical simulation and in-situ measurement. According to the production and geological condition of first face in Sima coal mine, the results indicate that the clay contains large permissible bearing ability and has better arching force. After mining destruction, stable structure is formed in bedrock to ensure face safety. The clay thickness & bedrock thickness are the key influential elements to stable structure. The minimal bedrock thickness is about 40 m to ensure safe mining under loose surface soil condition. When surface soil contains mainly thick clay, it forms steady structure with the composition of thin bedrock, so that it can reduce minimal thickness of bedrock and to ensure safe mining. When clay thickness is 40 m, minimal bedrock thickness is 20 m. When clay thickness is 30 m, minimal bedrock thickness is 30 m. Bearing pressure peak ranges from 5 to 15 m in the front face under thin bedrock condition. The bearing pressure distribution range is 15 m. Main roof break distance is small, and initial weighting of main roof is not distinctive, while first periodic weighting of main roof is quite distinctive.

  6. The Natural Terrestrial Carbon Sequestration Potential of Rocky Mountain Soils Derived From Volcanic Bedrock

    Science.gov (United States)

    Yager, D. B.; Burchell, A.; Johnson, R. H.

    2008-12-01

    The possible economic and environmental ramifications of climate change have stimulated a range of atmospheric carbon mitigation actions, as well as, studies to understand and quantify potential carbon sinks. However, current carbon management strategies for reducing atmospheric emissions underestimate a critical component. Soils represent between 18 - 30% of the terrestrial carbon sink needed to prevent atmospheric doubling of CO2 by 2050 and a crucial element in mitigating climate change, natural terrestrial sequestration (NTS), is required. NTS includes all naturally occurring, cumulative, biologic and geologic processes that either remove CO2 from the atmosphere or prevent net CO2 emissions through photosynthesis and microbial fixation, soil formation, weathering and adsorption or chemical reactions involving principally alumino- ferromagnesium minerals, volcanic glass and clays. Additionally, NTS supports ecosystem services by improving soil productivity, moisture retention, water purification and reducing erosion. Thus, 'global climate triage' must include the protection of high NTS areas, purposeful enhancement of NTS processes and reclamation of disturbed and mined lands. To better understand NTS, we analyzed soil-cores from Colorado, Rocky Mountain Cordillera sites. North-facing, high-plains to alpine sites in non-wetland environments were selected to represent temperate soils that may be less susceptible to carbon pool declines due to global warming than soils in warmer regions. Undisturbed soils sampled have 2 to 6 times greater total organic soil carbon (TOSC) than global TOSC averages (4 - 5 Wt. %). Forest soils derived from weathering of intermediate to mafic volcanic bedrock have the highest C (34.15 Wt. %), C:N (43) and arylsulfatase (ave. 278, high 461 μg p-nitrophenol/g/h). Intermediate TOSC was identified in soils derived from Cretaceous shale (7.2 Wt. %) and Precambrian, felsic gneiss (6.2 Wt. %). Unreclaimed mine-sites have the lowest C (0

  7. Yield of bedrock wells in the Nashoba terrane, central and eastern Massachusetts

    Science.gov (United States)

    DeSimone, Leslie A.; Barbaro, Jeffrey R.

    2012-01-01

    The yield of bedrock wells in the fractured-bedrock aquifers of the Nashoba terrane and surrounding area, central and eastern Massachusetts, was investigated with analyses of existing data. Reported well yield was compiled for 7,287 wells from Massachusetts Department of Environmental Protection and U.S. Geological Survey databases. Yield of these wells ranged from 0.04 to 625 gallons per minute. In a comparison with data from 103 supply wells, yield and specific capacity from aquifer tests were well correlated, indicating that reported well yield was a reasonable measure of aquifer characteristics in the study area. Statistically significant relations were determined between well yield and a number of cultural and hydrogeologic factors. Cultural variables included intended water use, well depth, year of construction, and method of yield measurement. Bedrock geology, topography, surficial geology, and proximity to surface waters were statistically significant hydrogeologic factors. Yield of wells was higher in areas of granites, mafic intrusive rocks, and amphibolites than in areas of schists and gneisses or pelitic rocks; higher in valleys and low-slope areas than on hills, ridges, or high slopes; higher in areas overlain by stratified glacial deposits than in areas overlain by till; and higher in close proximity to streams, ponds, and wetlands than at greater distances from these surface-water features. Proximity to mapped faults and to lineaments from aerial photographs also were related to well yield by some measures in three quadrangles in the study area. Although the statistical significance of these relations was high, their predictive power was low, and these relations explained little of the variability in the well-yield data. Similar results were determined from a multivariate regression analysis. Multivariate regression models for the Nashoba terrane and for a three-quadrangle subarea included, as significant variables, many of the cultural and

  8. Integrated Methods for Site Characterization and Conceptual Model Development for a Contaminated Fractured-Bedrock Aquifer

    Science.gov (United States)

    Johnson, C. D.; Kastrinos, J. R.; Haeni, F. P.

    2005-12-01

    A multi-disciplined and team-based approach was used to integrate geophysical, hydrologic, and chemical data to characterize lithology, fractures, and hydraulic properties of fractured crystalline bedrock and to determine the nature and extent of ground-water contamination from a landfill and former chemical-waste disposal pits at the University of Connecticut. Detection of volatile organic compounds (VOCs) in domestic bedrock wells in the mid-1980s led to this investigation, in which a team comprised of hydrologists, engineers, geophysicists, geologists, chemists, toxicologists, and community-involvement personnel collected, analyzed, and evaluated data; developed and refined a conceptual model of the ground-water flow and contaminant distribution at the site; and evaluated alternatives and implemented a final remediation plan. The characterization phase began in 1999 and the remediation phase is currently ongoing. An integrated and iterative approach of using multiple methods in phases was important for corroborating the interpretation of individual methods and essential for guiding the design and implementation of additional testing at the site. The use of geophysical data early in the investigation allowed the study team to obtain detailed subsurface information using a minimum of boreholes. Surface geophysical methods were used to target potential discharge of contaminants from the landfill for further investigation. Borehole geophysical methods were used to investigate the anomalies identified by surface geophysical methods, the location and orientation of fractures that intersect and surround each well, the direction and magnitude of ambient flow in the wells, and the transmissive fractures that could provide pathways for contaminant migration. Borehole geophysical and hydraulic data were used to design discrete-zone monitoring systems for the collection of hydraulic head and chemical data and to prevent cross contamination through the boreholes. The results

  9. Indications of postglacial and recent bedrock movements in Finland and Russian Karelia

    Energy Technology Data Exchange (ETDEWEB)

    Kuivamaeki, A.; Vuorela, P.; Paananen, M

    1998-12-31

    This report is mainly a summary report of the studies done 1986 - 1997 by the Geological Survey of Finland/Nuclear Waste Disposal Research on postglacial faulting (PG-faults) and recent bedrock movements. Most of the results have already been published in other YST-reports in Finnish. The first part of the report deals with the postglacial faults in Finland and in the second part the problems connected with the origin and age of paleoseismic dislocations found in Russian Karelia are described. The final part deals with the present vertical and horizontal movements of Finnish bedrock. The Pasmajaervi PG-fault is the most thoroughly studied PG-fault in Finland. Around the fault lineament interpretations and geophysical ground measurements have been done and the fault zone has been penetrated with two drill holes. Three levelling networks and one GPS-network have been established for revealing any recent movements of the PG-fault area. Other PG-faults studied, but not in the same detail, are Venejaervi, Ruostejaervi, Suasselkae and Vaalajaervi PG-faults. The PG-faults in Finland strike in the SW-NE direction and dip to the SE with the exception of the Vaalajaervi PG-fault. It strikes in the NW-SE direction. The dip direction is unknown. The length of the PG-faults is 4-36 km and the scarp height 0-12 m. PG-faults are reverse faults and they are located in old, reactivated fracture zones. The results of drillings and resistivity soundings in the Pasmajaervi PG-fault indicate, that the dip angle of 45 deg in the surface becomes more gentle with the increasing depth. This result may be important from a technical point of view when designing nuclear waste repositories. The strike directions of the PG-faults are perpendicular with the direction of prevailing horizontal maximum stress. The structure and location of the PG-faults is in accordance with the model presented by Muir Wood for the origin of PG-faults. The exceptional direction of the Vaalajaervi PG-fault is

  10. Geochemistry of highly acidic mine water following disposal into a natural lake with carbonate bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Wisskirchen, Christian, E-mail: ChristianWisskirchen@web.de [Institute of Mineralogy and Geochemistry, University of Lausanne, CH-1015 Lausanne (Switzerland); Dold, Bernhard [Institute of Mineralogy and Geochemistry, University of Lausanne, CH-1015 Lausanne (Switzerland)] [Instituto de Geologia Economica Aplicada, Universidad de Concepcion, Concepcion (Chile); Friese, Kurt [UFZ - Helmholtz Centre for Environmental Research, Department of Lake Research, D-39114 Magdeburg (Germany); Spangenberg, Jorge E. [Institute of Mineralogy and Geochemistry, University of Lausanne, CH-1015 Lausanne (Switzerland); Morgenstern, Peter [UFZ - Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, D-04318 Leipzig (Germany); Glaesser, Walter [Institute of Geophysics and Geology, University of Leipzig, D-04211 Leipzig (Germany)

    2010-08-15

    Research highlights: {yields} Mean lake water element composition did not differ greatly from discharged AMD. {yields} Most elements showed increasing concentrations from the surface to lake bottom. {yields} Jarosite formed in the upper part, settled, and dissolved in the deeper part of the lake. {yields} Elements migrated into the underlying carbonates in the sequence As< Pb {approx} Cu < Cd < Zn = Mn. {yields} Gypsum and hydroxide precipitation had not resulted in complete clogging of the lake bedrocks. - Abstract: Acid mine drainage (AMD) from the Zn-Pb(-Ag-Bi-Cu) deposit of Cerro de Pasco (Central Peru) and waste water from a Cu-extraction plant has been discharged since 1981 into Lake Yanamate, a natural lake with carbonate bedrock. The lake has developed a highly acidic pH of {approx}1. Mean lake water chemistry was characterized by 16,775 mg/L acidity as CaCO{sub 3}, 4330 mg/L Fe and 29,250 mg/L SO{sub 4}. Mean trace element concentrations were 86.8 mg/L Cu, 493 mg/L Zn, 2.9 mg/L Pb and 48 mg/L As, which did not differ greatly from the discharged AMD. Most elements showed increasing concentrations from the surface to the lake bottom at a maximal depth of 41 m (e.g. from 3581 to 5433 mg/L Fe and 25,609 to 35,959 mg/L SO{sub 4}). The variations in the H and O isotope compositions and the element concentrations within the upper 10 m of the water column suggest mixing with recently discharged AMD, shallow groundwater and precipitation waters. Below 15 m a stagnant zone had developed. Gypsum (saturation index, SI {approx} 0.25) and anglesite (SI {approx} 0.1) were in equilibrium with lake water. Jarosite was oversaturated (SI {approx} 1.7) in the upper part of the water column, resulting in downward settling and re-dissolution in the lower part of the water column (SI {approx} -0.7). Accordingly, jarosite was only found in sediments from less than 7 m water depth. At the lake bottom, a layer of gel-like material ({approx}90 wt.% water) of pH {approx}1 with a

  11. Lithological and structural bedrock model of the Haestholmen study site, Loviisa, SE Finland

    Energy Technology Data Exchange (ETDEWEB)

    Front, K.; Paulamaeki, S.; Ahokas, H.; Anttila, P

    1999-10-01

    The Haestholmen study site is located within the anorogenic Wiborg rapakivi granite batholith, 1640 1630 Ma in age. The bedrock consists of various rapakivi granites, which can be divided into three groups or lithological units: (1) wiborgite and pyterlite, (2) porphyritic rapakivi granite, and (3) even-grained or weakly porphyritic rapakivi granite, pyterlite being the dominant rock type. The evengrained and weakly porphyritic rapakivi granite has been interpreted to form a younger intrusive unit with a thickness of ca. 500 m, dipping approx. 20 deg to the NNW-NNE. Surface fractures form a distinct orthogonal system, with three perpendicular fracture directions: fractures dipping steeply (dip >75 deg) to the NE-SW and NW-SE plus subhorizontal (dip <30 deg) fractures. The fracturing in the outcrops is sparse,the average fracture frequency being 0.6 fractures/m. The majority of the fractures in the drill cores are horizontal or very gently dipping and there is no difference in fracture orientations in regard to rock type or depth. Core samples are usually slightly fractured (1 - 3 fractures/m), even-grained rapakivi granites being in places abundantly fractured (3 10 fractures/m. The broken sections in Haestholmen core samples represent about 4.6 % of the total length of the samples. Calcite, dolomite, Fe- hydroxides and clay minerals (illite, montmorillonite and kaolinite) form the most typical fracture mineral phases throughout the drill cores. Core discing is locally seen as repeated fracture-like subparallel cracks in core with spacing of about some millimetres to tens of millimetres. The structural model contains 27 structures (denoted by the term R+number), more than half of which have been verified by direct observations from boreholes or from the VLJ repository. The remaining structures are mainly based on the geophysical interpretation, and have been classified as probable or possible fracture zones. In addition, local structures with uncertain orientation

  12. Soils and geomorphic evolution of bedrock facets on a tectonically active mountain front, western Sangre de Cristo Mountains, New Mexico

    Science.gov (United States)

    Menges, Christopher M.

    1990-09-01

    Soil profiles, colluvial stratigraphy, and detailed hillslope morphology are key elements used for geomorphic interpretations of the form and long-term evolution of triangular facets on a 1200 m high, tectonically active mountain front. The facets are developed on Precambrian gneisses and Tertiary volcanic and plutonic rocks along a complexly segmented, active normal-fault zone in the Rio Grande rift of northern New Mexico. The detailed morphologies of 20- to 350 m high facets are defined by statistical and time-series analyses of 40 field transects that were keyed to observations of colluvium, bedrock, microtopography, and vegetation. The undissected parts of most facets are transport-limited hillslopes mantled with varying thicknesses (0.1 to > 1 m thick) of sand and gravel colluvium between generally sparse (≤10-30%) bedrock outcrops. Facet soils range from (a) thin (≤ 0.2 m) weakly developed soils with cumulic silty A or transitional A/B epipedons above Cox horizons in bedrock or colluvium, to (b) deep (≥0.5-1 m) moderately to strongly developed profiles containing thick cambic (Bw) and/or argillic (Bt) horizons that commonly extend into highly weathered saprolitic bedrock. The presence of strongly weathered profiles and thick colluvium suggests that rates of colluvial transport and hillslope erosion are less than or equal to rates of soil development over at least a large part of the Holocene. The catenary variation of soils and colluvium on selected facet transects indicate that the degree of soil development generally increases and the thickness of colluvium decreases upslope on most facets. This overall pattern is commonly disrupted on large facet hillslopes by irregular secondary soil variations linked to intermediate-scale (20-60 + m long) concave slope elements. These features are interpreted to reflect discontinuous transport and erosion of colluvium down-slope below bedrock outcrops. The degree of weathering in subsurface bedrock commonly

  13. Hydrochemistry of the Mahomet Bedrock Valley Aquifer, East-Central Illinois: indicators of recharge and ground-water flow

    Science.gov (United States)

    Panno, S.V.; Hackley, Keith C.; Cartwright, K.; Liu, Chao-Li

    1994-01-01

    A conceptual model of the ground-water flow and recharge to the Mahomet Bedrock Valley Aquifer (MVA), east-central Illinois, was developed using major ion chemistry and isotope geochemistry. The MVA is a 'basal' fill in the east-west trending buried bedrock valley composed of clean, permeable sand and gravel to thicknesses of up to 61 m. It is covered by a thick sequence of glacial till containing thinner bodies of interbedded sand and gravel. Ground water from the MVA was found to be characterized by clearly defined geochemical regions with three distinct ground-water types. A fourth ground-water type was found at the confluence of the MVA and the Mackinaw Bedrock Valley Aquifer (MAK) to the west. Ground water in the Onarga Valley, a northeastern tributary of the MVA, is of two types, a mixed cation-SO42- type and a mixed cation-HCO3- type. The ground water is enriched in Na+, Ca2+, Mg2+, and SO42- which appears to be the result of an upward hydraulic gradient and interaction of deeper ground water with oxidized pyritic coals and shale. We suggest that recharge to the Onarga Valley and overlying aquifers is 100% from bedrock (leakage) and lateral flow from the MVA to the south. The central MVA (south of the Onarga Valley) is composed of relatively dilute ground water of a mixed cation-HCO3- type, with low total dissolved solids, and very low concentrations of Cl- and SO42-. Stratigraphic relationships of overlying aquifers and ground-water chemistry of these and the MVA suggest recharge to this region of the MVA (predominantly in Champaign County) is relatively rapid and primarily from the surface. Midway along the westerly flow path of the MVA (western MVA), ground water is a mixed cation-HCO3- type with relatively high Cl-, where Cl- increases abruptly by one to ??? two orders of magnitude. Data suggest that the increase in Cl- is the result of leakage of saline ground water from bedrock into the MVA. Mass-balance calculations indicate that approximately 9.5% of

  14. Radon in Soil Gas Above Bedrock Fracture Sets at the Shepley’s Hill Superfund Site

    Energy Technology Data Exchange (ETDEWEB)

    J.R. Giles; T.L. McLing; M.V. Carpenter; C.J. Smith; W. Brandon

    2012-12-01

    The Idaho National Laboratory (INL) recently provided technical support for ongoing environmental remediation activities at the Shepley’s Hill remediation site near Devens, MA (Figure 1). The technical support was requested as follow-on work to an initial screening level radiation survey conducted in 2008. The purpose of the original study was to assess the efficacy of the INL-developed Backpack Sodium Iodide System (BaSIS) for detecting elevated areas of natural radioactivity due to the decay of radon-222 gases emanating from the underlying fracture sets. Although the results from the initial study were mixed, the BaSIS radiation surveys did confirm that exposed bedrock outcrops have higher natural radioactivity than the surficial soils, thus a high potential for detecting elevated levels of radon and/or radon daughter products. (INL 2009) The short count times associated with the BaSIS measurements limited the ability of the system to respond to elevated levels of radioactivity from a subsurface source, in this instance radon gas emanating from fracture sets. Thus, it was postulated that a different methodology be employed to directly detect the radon in the soil gases. The CR-39 particle track detectors were investigated through an extensive literature and technology search. The relatively long deployment or “detection” time of several days, as well as the sensitivity of the measurement and robustness of the detectors made the CR-39 technology promising for deployment at the Shepley’s Hill site.

  15. Quaternary deposits and weathered bedrock material as a source of dangerous radon emissions in Estonia

    Directory of Open Access Journals (Sweden)

    Petersell Valter

    2015-06-01

    Full Text Available The risk of dangerous radon emissions in Estonia is high, being among the highest in Europe. In almost 33 per cent of Estonian land area, the content of radon in soil-contained air exceeds the safe limit for unrestricted construction (50 kBq/m3. In such high radon-risk areas the concentration of radon in soil-contained air ranges from 50 to 400 kBq/m3, in a few cases reaching up to 2,100 kBq/m3 exceeding the permitted level for residential areas. The situation is particularly serious in the northernmost part of the country, where uranium-rich graptolite argillite (Dictyonema shale and the Obolus phosphorite are close to ground surface and their particles are constituent parts of Quaternary deposits. Radon emissions from bedrock have been investigated in detail, but to date Quaternary strata as a source of radon emissions are poorly studied. According to our measurements the highest concentrations of radon are related to tills containing clasts and fines of graptolite argillite and phosphorite. Glacial deposits include also granitoidal material, containing U, Th and K, which have been transported by glaciers from the outcrop areas of crystalline basement rocks in Finland and the Gulf of Finland. Due to weathering, outwash and repeated redeposition other genetic types are poorer in radioactive elements and they are weaker sources of radon.

  16. Technical assessment of the bedrock waste storage at the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, R.F.; Corey, J.C.

    1976-11-01

    An assessment of the safety and feasibility of ultimate storage of radioactive wastes produced at the Savannah River Plant (SRP) in horizontal tunnels excavated in the bedrock beneath the plant site is presented. Results indicate that a cavern with an excavated volume of 130 million gallons could contain 80 million gallons of concentrated radioactive SRP wastes with minimal risks if the cavern is located in the impermeable Triassic Basin underlying the Savannah River site. The cavern could be placed so that it would lie wholly within the boundaries of the plantsite. The document summarizes the general geological, hydrological, and chemical knowledge of the geological structures beneath the plantsite; develops evaluation guidelines; and utilizes mathematical models to conduct risk analyses. The risk models are developed from known soil and salt solution mechanics; from past, present, and future geological behavior of the onsite rock formations; and from known waste handling technology. The greatest risk is assessed to exist during transfer of the radioactive wastes to the cavern. When the cavern is filled and sealed, further population risks are asessed to be very low.

  17. Evaluation of the ground surface Enthalpy balance from bedrock shallow borehole temperatures (Livingston Island, Maritime Antarctic

    Directory of Open Access Journals (Sweden)

    M. Ramos

    2008-03-01

    Full Text Available The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic is studied. The borehole is 2.4 m deep and is located in a quartzite outcrop in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth hourly temperature profiles from: (i the cooling periods of the frost seasons of 2000 to 2005, and (ii the warming periods of the thaw seasons of 2002–2003, 2003–2004 and 2004–2005, were studied. In this modelling approach, heat gains and losses across ground surface are considered to be the causes for the 0°C isotherm movement. A methodological approach to calculate the Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density is considered to be constant in the borehole and initial isothermal conditions at 0°C are assumed to run the model. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima.

  18. Eskers and bedrock gorges (tunnel valleys in the Pakasaivo area, western Finnish Lapland

    Directory of Open Access Journals (Sweden)

    Peter Johansson

    2003-01-01

    Full Text Available Studies of the deglaciation of the last Scandinavian Ice Sheet, including the behavior of the ice sheet and meltwater activity, were conducted in the vicinity of the Pakasaivo canyon lake, located in western Finnish Lapland. Pakasaivo itself, a circular basin up to 100 m deep, was formed in the broken bedrock by glacial erosion and meltwater streams. It was originally related to a former subglacial meltwater system, including the deep Keinokursu gorge. Both this gorge and the Pakasaivo canyon lake were formed subglacially duringan early stage of deglaciation. It was characterized by intense meltwater erosion, which in Pakasaivo also seems to have generated a strong whirl. Steep-crested esker ridges were subsequently deposited; subaerial meltwater activity then followed. Finally the meltwaterwas discharged from the ice-dammed lake north of the area and passed through the Pakasaivo canyon to the ice-free areas. This caused additional intense erosion of the canyon floor and walls, and the deep circular basin is highly similar to a plunge pool formed at the base of a cataract.

  19. Toward improved prediction of the bedrock depth underneath hillslopes: Bayesian inference of the bottom-up control hypothesis using high-resolution topographic data

    Science.gov (United States)

    Gomes, Guilherme J. C.; Vrugt, Jasper A.; Vargas, Eurípedes A.

    2016-04-01

    The depth to bedrock controls a myriad of processes by influencing subsurface flow paths, erosion rates, soil moisture, and water uptake by plant roots. As hillslope interiors are very difficult and costly to illuminate and access, the topography of the bedrock surface is largely unknown. This essay is concerned with the prediction of spatial patterns in the depth to bedrock (DTB) using high-resolution topographic data, numerical modeling, and Bayesian analysis. Our DTB model builds on the bottom-up control on fresh-bedrock topography hypothesis of Rempe and Dietrich (2014) and includes a mass movement and bedrock-valley morphology term to extent the usefulness and general applicability of the model. We reconcile the DTB model with field observations using Bayesian analysis with the DREAM algorithm. We investigate explicitly the benefits of using spatially distributed parameter values to account implicitly, and in a relatively simple way, for rock mass heterogeneities that are very difficult, if not impossible, to characterize adequately in the field. We illustrate our method using an artificial data set of bedrock depth observations and then evaluate our DTB model with real-world data collected at the Papagaio river basin in Rio de Janeiro, Brazil. Our results demonstrate that the DTB model predicts accurately the observed bedrock depth data. The posterior mean DTB simulation is shown to be in good agreement with the measured data. The posterior prediction uncertainty of the DTB model can be propagated forward through hydromechanical models to derive probabilistic estimates of factors of safety.

  20. Decadal changes in fault-scarp knickpoints by bedrock erosion following 1999 Chi-Chi Earthquake in Taiwan

    Science.gov (United States)

    Hayakawa, Yuichi S.; Matsuta, Nobuhisa; Maekado, Akira; Matsukura, Yukinori

    2010-05-01

    Surface ruptures along the Chelungpu thrust fault in west-central Taiwan caused formation of knickpoints (waterfalls) according with bedrock exposure in riverbeds when the 921 Chi-Chi Earthquake occurred on September 21, 1999. Since then the fault-scarp knickpoints have receded upstream at extremely rapid rates, causing bedrock incision for tens to hundreds of meters in length within a decade. The rapid erosion of the knickpoints provides us an opportunity to investigate actual changes of bedrock morphology of the rivers, and here we examine the changes in the knickpoint recession rates during the last decade from 1999 to 2009. Field measurements of the topography revealed that the mean rate of a knickpoint recession in the largest river (Ta-chia) was 3.3 m/y in the earlier 6 years (1999-2005) and 220 m/y in the last 4 years (2005-2009). This acceleration of the recession can be due to the increase in flood frequency and intensity, narrowing of the channel width, and/or anisotropy of rock strength (sandstones and mudstones) along the stream. The other knickpoints showed relatively similar recession rates throughout the decade on the order of 20-60 m/y. These rates are then compared to an empirical model of knickpoint recession, in which relevant physical parameters of erosive force of stream and bedrock resistance are involved as a dimensionless index. The actual recession rates of the knickpoints are considerably higher than those expected by the model, suggesting that abundant sediment particles supplied from upstream catchment enhance the knickpoint erosion. In fact, all the abundant gravels on the riverbed around the knickpoints that are supplied from further upstream areas with different lithology (mostly older sandstones) are quite harder than the bedrock therein. The model analysis for the two time periods for each knickpoint suggests that the changes in their recession rates can be commonly affected by severe flood occurrence in the study area. Also, some

  1. Chemistry and dissolved gases of matrix pore water and fluid inclusions in Olkiluoto bedrock from drillhole ONK-PH9

    Energy Technology Data Exchange (ETDEWEB)

    Eichinger, F.; Haemmerli, J.; Waber, H.N.; Diamond, L.W. [Univ. of Bern (Switzerland). Inst. of Geological Sciences; Smellie, J.A.T. [Conterra AB, Stockholm (Sweden)

    2013-05-15

    Matrix pore water and gas dissolved in matrix pore water in drillcore samples from drillhole ONK-PH9 have been successfully characterised for their chemical and isotopic composition. Based on the comparison of natural tracers in matrix pore water and adjacent fracture groundwater, conclusions about the palaeohydrogeological history of the encountered system are drawn. The investigations are based on naturally saturated core samples from the subhorizontal drillhole ONK-PH9 which was drilled from the ONKALO access tunnel at a vertical depth of 306 m into the bedrock intersecting the water-conducting hydrogeological zone HZ20B. Pore water samples were taken from this highly transmissive water-conducting zone and the adjacent low transmissive bedrock along a continuous eleven metre long profile. Additional samples have been collected at intervals between five and ten metres until 100 m drillhole length (DHL)

  2. Bedrock morphology and structure, upper Santa Cruz Basin, south-central Arizona, with transient electromagnetic survey data

    Science.gov (United States)

    Bultman, Mark W.; Page, William R.

    2016-10-31

    The upper Santa Cruz Basin is an important groundwater basin containing the regional aquifer for the city of Nogales, Arizona. This report provides data and interpretations of data aimed at better understanding the bedrock morphology and structure of the upper Santa Cruz Basin study area which encompasses the Rio Rico and Nogales 1:24,000-scale U.S. Geological Survey quadrangles. Data used in this report include the Arizona Aeromagnetic and Gravity Maps and Data referred to here as the 1996 Patagonia Aeromagnetic survey, Bouguer gravity anomaly data, and conductivity-depth transforms (CDTs) from the 1998 Santa Cruz transient electromagnetic survey (whose data are included in appendixes 1 and 2 of this report).Analyses based on magnetic gradients worked well to identify the range-front faults along the Mt. Benedict horst block, the location of possibly fault-controlled canyons to the west of Mt. Benedict, the edges of buried lava flows, and numerous other concealed faults and contacts. Applying the 1996 Patagonia aeromagnetic survey data using the horizontal gradient method produced results that were most closely correlated with the observed geology.The 1996 Patagonia aeromagnetic survey was used to estimate depth to bedrock in the upper Santa Cruz Basin study area. Three different depth estimation methods were applied to the data: Euler deconvolution, horizontal gradient magnitude, and analytic signal. The final depth to bedrock map was produced by choosing the maximum depth from each of the three methods at a given location and combining all maximum depths. In locations of rocks with a known reversed natural remanent magnetic field, gravity based depth estimates from Gettings and Houser (1997) were used.The depth to bedrock map was supported by modeling aeromagnetic anomaly data along six profiles. These cross sectional models demonstrated that by using the depth to bedrock map generated in this study, known and concealed faults, measured and estimated magnetic

  3. Study of the engineering geologic feature of weathering zone of bedrock in 810 producing area of Luling Mine

    Institute of Scientific and Technical Information of China (English)

    桂和荣; 孙家斌; 李明好; 李伟; 尹正柱; 陈富勇; 宋晓梅

    2002-01-01

    For a safe extracting of the mine resource of the razor-thin capping rock, a study of waterproof, sand prevention, roof-fall prevention must be made. As a result, its necessary to master the engineering feature of weathering zone of bedrock. According to the lithology appraisal and X diffract analyses, the mineral feature of weathering zone of bedrock in 810 producing area has been studied in this article. By testing the physical mechanics index of weathering zone, we have found out some features of physical mechanic quality. Utilizing the determined result of viscosity index and slaking test, we reach a conclusion of the water stability of weathering zone, that is the weathering zone rock belongs to the type that is easily slaked when encountered water and the water stability is weak.

  4. Evaluating the controls of shear stress, sediment supply, alluvial cover, and channel morphology on experimental bedrock incision rate

    Science.gov (United States)

    Johnson, Joel P. L.; Whipple, Kelin X.

    2010-06-01

    We explored the dependence of experimental bedrock erosion rate on shear stress, bed load sediment flux, alluvial bed cover, and evolving channel morphology. We isolated these variables experimentally by systematically varying gravel sediment flux Qs and water discharge Qw in a laboratory flume, gradually abrading weak concrete "bedrock." All else held constant, we found that (1) erosion rate was insensitive to flume-averaged shear stress, (2) erosion rate increased linearly with sediment flux, (3) erosion rate decreased linearly with the extent of alluvial bed cover, and (4) the spatial distribution of bed cover was sensitive to local bed topography, but the extent of cover increased with Qs/Qt (where Qt is flume-averaged transport capacity) once critical values of bed roughness and sediment flux were exceeded. Starting from a planar geometry, erosion increased bed roughness due to feedbacks between preferential sediment transport through interconnected topographic lows, focused erosion along these zones of preferential bed load transport, and local shear stresses that depended on the evolving bed morphology. Finally, continued growth of bed roughness was inhibited by imposed variability in discharge and sediment flux, due to changes in spatial patterns of alluvial deposition and impact wear. Erosion was preferentially focused at lower bed elevations when the bed was cover-free, but was focused at higher bed elevations when static alluvial cover filled topographic lows. Natural variations in discharge and sediment flux may thus stabilize and limit the growth of roughness in bedrock channels due to the effects of partial bed cover.

  5. Validation of GEOtop Model for Permafost Research on Steep High-Mountain Bedrock

    Science.gov (United States)

    Pogliotti, P.; Cremonese, E.; Dall'Amico, M.; Gruber, S.; Migliavacca, M.; Morra di Cella, U.

    2009-04-01

    Permafrost distribution in high-mountain environments is influenced in a complex way by topography (micro-climate) and high variability of ground covers conditions (debris, snow, etc.). Also, its direct monitoring is very difficult due to logistical problems like accessibility, costs, weather conditions and reliability of instrumentation. In such conditions physically-based modelling of surface rock/ground temperatures is fundamental for the understanding of mountain permafrost dynamics. With this awareness, a 1D version of GEOtop model has been tested in several high-mountain sites and its accuracy to reproduce near-surface bedrock temperature, solar radiation and snow cover depth, has been evaluated using independent field measurements. GEOtop is a distributed hydrological model with coupled water and energy budgets and is currently under development to suit permafrost research in such complex morphologies. Most of the validation runs have been performed using dataset coming from Corvatsch (3315 m a.s.l., Swiss Alps) since long time-series of meteorological observation are available and many monitoring sites of surface rock temperatures have been equipped during the last years by the University of Zurich. For the validation of modelled snow cover and solar radiation two different dataset coming from Valtournenche (Italian Alps) have been used: Cime Bianche Pass (3100 m a.s.l) and Matterhorn SW ridge (3830 m s.l.m.) equipped by A.R.P.A. Valle d'Aosta. On each site, a 1D GEOtop simulation of temporal duration equal to the full set of meteorological observations (1982-2008) was performed. The first 4 years are used to define the initial conditions by an iterative initialization procedure, in order to obtain an equilibrium between the deep temperature profile and atmospheric conditions. In order to highlight or structural model's deficiencies, ground properties such as albedo, emissivity, thermal conductivity and roughness length are kept fixed over all sites. For

  6. Uplift of the Transantarctic Mountains and the bedrock beneath the East Antarctic ice sheet

    Science.gov (United States)

    ten Brink, U.S.; Hackney, R.I.; Bannister, S.; Stern, T.A.; Makovsky, Y.

    1997-01-01

    In recent years the Transantarctic Mountains (TAM), the largest noncontractional mountain belt in the world, have become the focus of modelers who explained their uplift by a variety of isostatic and thermal mechanisms. A problem with these models is a lack of available data to compare with model predictions. We report here the results of a 312-km-long geophysical traverse conducted in 1993/1994 in the hinterland of the TAM. Using detailed subglacial topography and gravity measurements, we confirm the origin of the TAM as a flexural uplift of the edge of East Antarctica. Using an elastic model with a free edge, we can jointly fit the topography and the gravity with a plate having an elastic thickness of 85 ?? 15 km and a preuplift elevation of 700 ?? 50 m for East Antarctica. Using a variety of evidence, we argue that the uplift is coincident with a relatively minor tectonic event of transtensional motion between East and West Antarctica during the Eocene rather than the Late Cretaceous rifting event that created the Ross Embayment. We suggest that this transtensional motion caused the continuous plate to break, which created an escarpment that significantly increased the rates of erosion and exhumation. Results from the geophysical traverse also extend our knowledge of the bedrock geology from the exposures within the TAM to the ice covered interior. Our interpretation suggests that the Ferrar flood basalts extend at least 100 km westward under the ice. The Beacon Supergroup of Paleozoic and Mesozoic sediments thins gradually under the ice and its reconstructed thickness is reminiscent of profiles of foreland basins. Finally, there is no indication in the gravity field for an incomplete rebound due to significant melting of the East Antarctic ice sheet since the last glacial period.

  7. Quantifying irreversible movement in steep, fractured bedrock permafrost on Matterhorn (CH)

    Science.gov (United States)

    Weber, Samuel; Beutel, Jan; Faillettaz, Jérome; Hasler, Andreas; Krautblatter, Michael; Vieli, Andreas

    2017-02-01

    Understanding rock slope kinematics in steep, fractured bedrock permafrost is a challenging task. Recent laboratory studies have provided enhanced understanding of rock fatigue and fracturing in cold environments but were not successfully confirmed by field studies. This study presents a unique time series of fracture kinematics, rock temperatures and environmental conditions at 3500 m a. s. l. on the steep, strongly fractured Hörnligrat of the Matterhorn (Swiss Alps). Thanks to 8 years of continuous data, the longer-term evolution of fracture kinematics in permafrost can be analyzed with an unprecedented level of detail. Evidence for common trends in spatiotemporal pattern of fracture kinematics could be found: a partly reversible seasonal movement can be observed at all locations, with variable amplitudes. In the wider context of rock slope stability assessment, we propose separating reversible (elastic) components of fracture kinematics, caused by thermoelastic strains, from the irreversible (plastic) component due to other processes. A regression analysis between temperature and fracture displacement shows that all instrumented fractures exhibit reversible displacements that dominate fracture kinematics in winter. Furthermore, removing this reversible component from the observed displacement enables us to quantify the irreversible component. From this, a new metric - termed index of irreversibility - is proposed to quantify relative irreversibility of fracture kinematics. This new index can identify periods when fracture displacements are dominated by irreversible processes. For many sensors, irreversible enhanced fracture displacement is observed in summer and its initiation coincides with the onset of positive rock temperatures. This likely indicates thawing-related processes, such as meltwater percolation into fractures, as a forcing mechanism for irreversible displacements. For a few instrumented fractures, irreversible displacements were found at the

  8. Uranium and radon in private bedrock well water in Maine: geospatial analysis at two scales

    Science.gov (United States)

    Yang, Qiang; Smitherman, Paul; Hess, C.T.; Culbertson, Charles W.; Marvinney, Robert G.; Zheng, Yan

    2014-01-01

    In greater Augusta of central Maine, 53 out of 1093 (4.8%) private bedrock well water samples from 1534 km2 contained [U] >30 μg/L, the U.S. Environmental Protection Agency’s (EPA) Maximum Contaminant Level (MCL) for drinking water; and 226 out of 786 (29%) samples from 1135 km2 showed [Rn] >4,000 pCi/L (148 Bq/L), the U.S. EPA’s Alternative MCL. Groundwater pH, calcite dissolution and redox condition are factors controlling the distribution of groundwater U but not Rn due to their divergent chemical and hydrological properties. Groundwater U is associated with incompatible elements (S, As, Mo, F, and Cs) in water samples within granitic intrusions. Elevated [U] and [Rn] are located within 5–10 km distance of granitic intrusions but do not show correlations with metamorphism at intermediate scales (100−101 km). This spatial association is confirmed by a high-density sampling (n = 331, 5–40 samples per km2) at local scales (≤10–1 km) and the statewide sampling (n = 5857, 1 sample per 16 km2) at regional scales (102–103 km). Wells located within 5 km of granitic intrusions are at risk of containing high levels of [U] and [Rn]. Approximately 48 800–63 900 and 324 000 people in Maine are estimated at risk of exposure to U (>30 μg/L) and Rn (>4000 pCi/L) in well water, respectively.

  9. Evidence for extensive olivine-rich basalt bedrock outcrops in Ganges and Eos chasmas, Mars

    Science.gov (United States)

    Edwards, C. S.; Christensen, P. R.; Hamilton, V. E.

    2008-11-01

    Several localized outcrops of olivine-enriched bedrock have been previously identified in the Ganges and Eos Chasma area on the eastern end of Valles Marineris with the Thermal Emission Imaging System multispectral images. These outcrops form a layer in the walls of Ganges Chasma and appear to be the remnants of a once continuous unit, which was mapped over ~100 km. In this study we further characterize the composition (forsterite content of ~0.68), olivine abundance (10 to >15%), thermal inertia (>600 JK-1 m-2 s-1/2, consistent with in-place rocky material), vertical dimension (~60 to ~220 m), extent (>1100 km laterally), volume (~9.9 × 104 km3), dip (~0.013°NE), and continuity of this layer utilizing Thermal Emission Spectrometer hyperspectral, Thermal Emission Imaging System multispectral, and Mars Orbiter Laser Altimeter elevation data. Morphologic data from high-resolution imagery display a relatively unmantled, rough, and pitted surface associated with the olivine-enriched material, consistent with thermal inertia data. Four possibilities for the origin of the olivine-enriched unit are (1) volcanism associated with tectonic rifting of the Valles Marineris system, (2) a volcaniclastic flow deposit, (3) an intrusive mafic sill, or (4) a discrete episode in Martian history during which flood lavas were erupted onto the surface. The most likely origin is an eruptive event consisting of compositionally uniform flood lavas originating from a primitive mantle source region, possibly associated with the initiation of Tharsis volcanism. This unit is one of the largest continuous compositional units found on Mars and is strikingly similar to other olivine-enriched deposits identified in previous studies where compositional, morphologic, and thermophysical similarities are observed. These similarities may indicate that there was a period in early Martian history, where compositionally uniform and extensive olivine-enriched flood basalts were erupted on the Martian

  10. Uranium and radon in private bedrock well water in Maine: geospatial analysis at two scales.

    Science.gov (United States)

    Yang, Qiang; Smitherman, Paul; Hess, C T; Culbertson, Charles W; Marvinney, Robert G; Smith, Andrew E; Zheng, Yan

    2014-04-15

    In greater Augusta of central Maine, 53 out of 1093 (4.8%) private bedrock well water samples from 1534 km(2) contained [U] >30 μg/L, the U.S. Environmental Protection Agency's (EPA) Maximum Contaminant Level (MCL) for drinking water; and 226 out of 786 (29%) samples from 1135 km(2) showed [Rn] >4,000 pCi/L (148 Bq/L), the U.S. EPA's Alternative MCL. Groundwater pH, calcite dissolution and redox condition are factors controlling the distribution of groundwater U but not Rn due to their divergent chemical and hydrological properties. Groundwater U is associated with incompatible elements (S, As, Mo, F, and Cs) in water samples within granitic intrusions. Elevated [U] and [Rn] are located within 5-10 km distance of granitic intrusions but do not show correlations with metamorphism at intermediate scales (10(0)-10(1) km). This spatial association is confirmed by a high-density sampling (n = 331, 5-40 samples per km(2)) at local scales (≤10(-1) km) and the statewide sampling (n = 5857, 1 sample per 16 km(2)) at regional scales (10(2)-10(3) km). Wells located within 5 km of granitic intrusions are at risk of containing high levels of [U] and [Rn]. Approximately 48 800-63 900 and 324 000 people in Maine are estimated at risk of exposure to U (>30 μg/L) and Rn (>4000 pCi/L) in well water, respectively.

  11. Isotopic Evidence for Microbial Activity in Crystalline Bedrock Fractures - a Case Study from Olkiluoto, SW Finland

    Science.gov (United States)

    Sahlstedt, E. K.; Karhu, J.; Pitkänen, P.

    2015-12-01

    Changes in the geochemical environment in crystalline bedrock fractures were investigated using the stable isotopes of C, O and S in fracture filling minerals as tracers. Of special interest were the possible changes which may occur in the subsurface at low temperatures. Especially, the influence of microbial activity was recognized as a catalyst for inducing changes in the geochemical environment. The study site is the Olkiluoto island located on the western coast of Finland, planned to host a geological repository for nuclear waste. Fracture surfaces were investigated to recognize the latest mineralizations at the site. These fillings were comprised of thin plates or small euhedral crystals of calcite and pyrite. The carbon and sulfur isotope compositions of calcite and pyrite were measured from bulk material by conventional IRMS, and in situ by secondary ion mass spectrometry. A notable feature of the late-stage fillings was high variabilities in the δ13C values of calcite and the δ34S values of pyrite, which ranged from -53.8 ‰ to +31.6 ‰ and from -50.4 ‰ to +77.7 ‰, respectively. Based on the isotopic compositions of the fillings, several features in the past hydrogeochemical environment could be recognized. The isotopic composition of the fracture fillings indicate an environment which was stratified with respect to depth. Characteristic features include bacterial sulfate reduction (BSR) occurring at depths 50 m. It appears that methanic conditions were replaced by sulfate reduction at depths >50 m likely due to infiltration of SO42--rich brackish waters. Sulfate reducing bacteria used mainly surface derived organic carbon as electron donors. Some indication of minor methanotrophic activity was recognized in anomalously low δ13C values of calcite, down to -53.8 ‰, at the depth range of 34-54 m. This methanotrophic activity may have been related to bacteria using CH4 as an electron donor in BSR.

  12. Comparing the Planform Morphologies of a Freely Meandering Channel and the Bedrock- Controlled South River, VA.

    Science.gov (United States)

    Narinesingh, P.; Pizzuto, J.

    2008-12-01

    The planforms of the lithologically controlled South River, VA, and the freely meandering Teklanika River, AK were investigated using two statistical methods as well as fractal and spectral analyses. The lithologic controls along the South River include riverbanks consisting of pre-Holocene terraces and alluvial fans, and highly resistant bedrock that frequently crops out both in the bed and along the banks. A statistical analysis of bends composed of single arcs shows that the average radius of curvature is six times greater and the average bend length is 25 percent smaller for the South River relative to the meandering river, indicating that lithologically controlled bends are less curved and shorter than freely-formed meander bends. Fractal analysis reveals that the meandering river displays a smaller range in length scales than the South River, which exhibits a wider range in length scales that reflect a wider distribution of bend sizes. The method of Lancaster and Bras, (2002), which identifies bends of different complexity, indicates that the meandering river displays bends composed of single arcs, complex arcs and multiple complex arcs. Unlike the freely meandering Teklanika River, the lithologically controlled South River does not display bends composed of multiple complex arcs, though bends composed of single and complex arcs are common. Spectral analysis reveals that the meandering river's pattern is composed of a relatively narrow range of dominant wavelengths with the most prominent wavelength being the longest, while the lithologically controlled river displays dominant wavelengths over a relatively wide range and the most prominent wavelength is not the longest. This analysis demonstrates that lithological controls increase the range of bend lengths, increase radii of curvature, simplify bend shapes, and increase the distribution of wavelengths of sinuous rivers.

  13. Borehole environmental tracers for evaluating net infiltration and recharge through desert bedrock

    Science.gov (United States)

    Heilweil, V.M.; Solomon, D.K.; Gardner, P.M.

    2006-01-01

    Permeable bedrock aquifers in arid regions are being increasingly developed as water supplies, yet little is generally known about recharge processes and spatial and temporal variability. Environmental tracers from boreholes were used in this study to investigate net infiltration and recharge to the fractured Navajo Sandstone aquifer. Vadose zone tracer profiles at the Sand Hollow study site in southwestern Utah look similar to those of desert soils at other sites, indicating the predominance of matrix flow. However, recharge rates are generally higher in the Navajo Sandstone than in unconsolidated soils in similar climates because the sandstone matrix allows water movement but not root penetration. Water enters the vadose zone either as direct infiltration of precipitation through exposed sandstone and sandy soils or as focused infiltration of runoff. Net infiltration and recharge exhibit extreme spatial variability. High-recharge borehole sites generally have large amounts of vadose zone tritium, low chloride concentrations, and small vadose zone oxygen-18 evaporative shifts. Annual net-infiltration and recharge rates at different locations range from about 1 to 60 mm as determined using vadose zone tritium, 0 to 15 mm using vadose zone chloride, and 3 to 60 mm using groundwater chloride. Environmental tracers indicate a cyclical net-infiltration and recharge pattern, with higher rates earlier in the Holocene and lower rates during the late Holocene, and a return to higher rates during recent decades associated with anomalously high precipitation during the latter part of the 20th century. The slightly enriched stable isotopic composition of modern groundwater indicates this recent increase in precipitation may be caused by a stronger summer monsoon or winter southern Pacific El Nin??o storm track. ?? Soil Science Society of America.

  14. Digital bedrock mapping at the Geological Survey of Norway: BGS SIGMA tool and in-house database structure

    Science.gov (United States)

    Gasser, Deta; Viola, Giulio; Bingen, Bernard

    2016-04-01

    Since 2010, the Geological Survey of Norway has been implementing and continuously developing a digital workflow for geological bedrock mapping in Norway, from fieldwork to final product. Our workflow is based on the ESRI ArcGIS platform, and we use rugged Windows computers in the field. Three different hardware solutions have been tested over the past 5 years (2010-2015). (1) Panasonic Toughbook CE-19 (2.3 kg), (2) Panasonic Toughbook CF H2 Field (1.6 kg) and (3) Motion MC F5t tablet (1.5 kg). For collection of point observations in the field we mainly use the SIGMA Mobile application in ESRI ArcGIS developed by the British Geological Survey, which allows the mappers to store georeferenced comments, structural measurements, sample information, photographs, sketches, log information etc. in a Microsoft Access database. The application is freely downloadable from the BGS websites. For line- and polygon work we use our in-house database, which is currently under revision. Our line database consists of three feature classes: (1) bedrock boundaries, (2) bedrock lineaments, and (3) bedrock lines, with each feature class having up to 24 different attribute fields. Our polygon database consists of one feature class with 38 attribute fields enabling to store various information concerning lithology, stratigraphic order, age, metamorphic grade and tectonic subdivision. The polygon and line databases are coupled via topology in ESRI ArcGIS, which allows us to edit them simultaneously. This approach has been applied in two large-scale 1:50 000 bedrock mapping projects, one in the Kongsberg domain of the Sveconorwegian orogen, and the other in the greater Trondheim area (Orkanger) in the Caledonian belt. The mapping projects combined collection of high-resolution geophysical data, digital acquisition of field data, and collection of geochronological, geochemical and petrological data. During the Kongsberg project, some 25000 field observation points were collected by eight

  15. Inverse modeling of soil water content to estimate the hydraulic properties of a shallow soil and the associated weathered bedrock

    Science.gov (United States)

    Le Bourgeois, O.; Bouvier, C.; Brunet, P.; Ayral, P.-A.

    2016-10-01

    Modeling soil water flow requires the knowledge of numerous parameters associated to the water content and the soil hydraulic properties. Direct estimations of those parameters in laboratory require expensive equipment and the obtained parameters are generally not representative at the field scale because of the limitation of core sample size. Indirect methods such as inverse modeling are known to get efficient estimations and are easier to set up and process for large-scale studies. In this study, we investigated the capacity of an inverse modeling procedure to estimate the soil and the bedrock hydrodynamic properties only from in situ soil water content measurements at multiple depths under natural conditions. Multi-objective parameter optimization was performed using the HYDRUS-1D software and an external optimization procedure based on the NSGA-II algorithm. In a midslope shallow soil, water content was monitored at 3 depths, 20, 40, and 60 cm during 12 intense rainfall events, whose amounts ranged between 50 and 250 mm and duration between 1 and 5 days. The vertical profile was considered as 2 layers of soils above a third layer representing the weathered schist rock. This deep layer acted as a deep boundary condition, which features the bedrock permeability and water storage. Each layer was described trough the 6 parameters of the Mualem-van Genuchten formulation. The calibrated parameters appeared to have very low uncertainty while allowing a good modelisation of the observed water content variations. The calibrated saturated water content was close to the laboratory porosity measurements while the saturated hydraulic conductivity showed that the soil was highly permeable, as measured in the field. The inverse modeling approach allowed an estimation of the hydraulic properties of the bedrock layer where no measurement was available. The bedrock layer was found to have a low saturated hydraulic conductivity (model failed sometimes to reproduce the saturation

  16. Geology, Bedrock, Barnardsville Quad line work. Incomplete lines., Published in 2006, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2006. It is described as...

  17. Digital bedrock geologic map of the Vermont part of the 7.5 x 15 minute Mount Ascutney and Springfield quadrangles, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG96-733A Walsh, GJ, Armstrong, TR and Ratcliffe, NM, 1996, Digital bedrock geologic map of the Vermont part of the 7.5 x 15 minute Mount Ascutney...

  18. Geology, Bedrock, Wisconsin Geologic and Natural History Survey has these maps, Published in 2006, 1:24000 (1in=2000ft) scale, Lafayette County Land Records.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2006. It is described as...

  19. Digital Polygon Model Grid of the Hydrogeologic Framework of Bedrock Units for a Simulation of Groundwater Flow for the Lake Michigan Basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The hydrogeologic framework for the Lake Michigan Basin model was developed by grouping the bedrock geology of the study area into hydrogeologic units on the basis...

  20. Geology, Bedrock, Zionville Quad line work. Incomplete lines., Published in 2006, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2006. It is described as...

  1. Geology, Bedrock, Sherwood Quad line work. Incomplete lines., Published in 2006, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2006. It is described as...

  2. Erodibility of Titan ice bedrock constrained by laboratory measurements of ice strength and erosion by sediment impacts

    Science.gov (United States)

    Sklar, L. S.; Collins, G. C.; Litwin, K. L.; Polito, P. J.; Zygielbaum, B. R.

    2012-12-01

    Saturn's moon Titan has a remarkably earth-like surface morphology, with branching fluvial networks draining elevated terrain. A paucity of impact craters suggests fluvial dissection is active and that the pace of landscape evolution is rapid. A key limitation on modeling rates of incision by Titan's rivers of liquid methane has been a lack of information on the erodibility of water-ice bedrock at ultra-cold temperatures. Here we report results from laboratory measurements of ice resistance to tensile fracture and rates of erosion of Titan bedrock analogs by low-velocity sediment impacts. We apply these experimental results to modeling fluvial incision, and explore constraints on rates and frequency of channel cutting on Titan. We made test samples of polycrystalline ice with a narrow and wide size distribution of seed ice grains. For some samples we added solid impurities composed of basalt, urea, and ammonium-sulfate, to account for the possibility that Titan's ice bedrock also contains silicates from meteors, organic polymers derived from Titan's atmosphere, and ammonia-based compounds formed by cryovolcanism. The experiments were conducted in a walk-in freezer and environmental chamber, where we varied temperature between 260 and 110 K using dry ice and liquid nitrogen (LN). For terrestrial rocks, resistance to erosion by sediment impacts depends on the kinetic energy required to detach a unit volume, which has been shown to scale with the square of tensile strength. We measured the tensile strength of Titan bedrock analogs using the Brazilian splitting test and found that strength increases with decreasing temperature at 7 kPa/K, for all ice types tested. Ice at Titan temperatures is thus roughly twice as strong as at terrestrial conditions; ice is strengthened by increasing impurity concentrations, finer grain-size distributions, and lower porosity. To replicate erosion of ice bedrock by bedload sediment impacts, we filled a 55-gallon drum with various ice

  3. Late Cenozoic exhumation of New Zealand: inversion from bedrock thermochronological ages

    Science.gov (United States)

    Jiao, Ruohong; Herman, Frédéric; Seward, Diane

    2016-04-01

    In the SW Pacific, the present subaerial land area of New Zealand straddles the boundary between the Australian and Pacific Plates. This margin has been converging since the mid-Eocene-late Oligocene, leading to a period of widespread crustal deformation and exhumation. During the past decades, the exhumation of the New Zealand basement has been the basis of many thermochronological studies, resulting in a large number of data from the Palaeozoic and Mesozoic bedrocks. We compiled the cooling ages from multiple thermochronological systems (i.e. apatite and zircon (U-Th)/He, apatite and zircon fission-track, K-feldspar, muscovite, biotite and hornblende 40Ar/39Ar or K-Ar) that yielded cooling events younger than 25 Ma, and formally inverted this data set to estimate the large-scale temporal and spatial variations in the exhumation rates of New Zealand during the late Cenozoic. The exhumation results show good agreement with the predicted off-shore sedimentation rates, while the thermal model used in the inversion is in part constrained by the present-day observed surface heat flow. The modelling results indicate crustal exhumation from the earliest Miocene (just prior to 20 Ma). But from ~10 Ma, a moderate acceleration of exhumation is observed at most sites, coincident with an important change in the orientation of the Pacific motion relative to the Australian Plate. Since the Quaternary, rapid exhumation has occurred in the Southern Alps along the west coast of South Island, with the highest rates in the central part of range. In this region, our estimates of the million-year-scale exhumation rates are in general coincidence with those previously estimated over shorter (i.e. 0.1 Ma and 10 ka) time scales, as well as with the contemporary rock uplift rates derived from GPS data, confirming exhumational steady-state in the orogeny. In contrast in eastern North Island, the predicted Quaternary exhumation rates are much lower than the recent rock uplift rates measured

  4. Attributes for NHDPlus Catchments (Version 1.1) in the Conterminous United States: Bedrock Geology

    Science.gov (United States)

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This data set represents the area of bedrock geology types in square meters compiled for every catchment of NHDPlus for the conterminous United States. The source data set is the "Geology of the Conterminous United States at 1:2,500,000 Scale--A Digital Representation of the 1974 P.B. King and H.M. Beikman Map" (Schuben and others, 1994). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus

  5. Bedrock control on the Assu Incised Valley morphology and sedimentation in the Brazilian Equatorial Shelf

    Institute of Scientific and Technical Information of China (English)

    Moab Praxedes Gomes; Helenice Vital; Karl Stattegger; Klaus Schwarzer

    2016-01-01

    control of the bedrock on valley incision and infill response to the last fall and rise in sea level on narrow, shallow and low-gradient shelves.

  6. Quantifying the growth of a rapidly eroding bedrock gorge using repeat terrestrial Lidar

    Science.gov (United States)

    Cook, K. L.

    2012-12-01

    The Da'an River Gorge in western Taiwan provides a unique opportunity to observe the formation and evolution of a natural bedrock gorge. The 1.2 km long and up to 20 m deep gorge has formed since 1999 in response to uplift of the riverbed during the Chi-Chi earthquake. The extremely rapid pace of erosion enables us to observe both downcutting and channel widening over short time periods. We have monitored the evolution of the gorge since 2009 using repeat RTK GPS surveys and terrestrial Lidar scans. GPS surveys of the channel profile are conducted frequently, with 24 surveys to date, while Lidar scans are conducted after major floods, or after 5-9 months without a flood, for a total of 8 scans to date. The Lidar data are most useful for recording erosion of channel walls, which is quite episodic and highly variable along the channel. By quantifying the distribution of wall erosion in space and time, we can improve our understanding of channel widening processes and of the development of the channel planform, particularly the growth of bends. During the summer of 2012, the Da'an catchment experienced two large storm events, a meiyu (plum rain) event on June 10-13 that brought 800 mm of rain, and a typhoon on August 1-3 that brought 650 mm of rain. The resulting floods had significant geomorphic effects on the Da'an gorge, including up to 10s of meters of erosion on some sections of the gorge walls. We quantify these changes using Lidar surveys conducted on June 7, July 3, and in mid-August. Channel wall collapses also occur in the absence of large floods, and we use scans from August 23, 2011 and June 7, 2012 to quantify erosion during a period that included a number of small floods, but no large ones. This allows us to compare the impact of 9 months of normal conditions to the impact of short-duration extreme events.Before June flood After June flood

  7. Single-well injection-withdrawal tests (SWIW). Literature review and scoping calculations for homogeneous crystalline bedrock conditions

    Energy Technology Data Exchange (ETDEWEB)

    Nordqvist, Rune; Gustafsson, Erik [Geosigma AB, Uppsala (Sweden)

    2002-08-01

    This report describes a literature review and scoping calculations carried out in order to test the feasibility of using SWIW (Single Well Injection Withdrawal) tracer experiments for expected hydraulic conditions in Swedish bedrock. The motivation for using SWIW tests in the site investigation programme is that extensive cross-hole tracer tests may not be possible and that such SWIW tests are more or less the only available single-hole tracer test method. The scoping calculations are aimed at establishing conditions under which SWIW tests should be feasible, by studying experimental attributes such as expected bedrock properties (transmissivity, porosity, etc), ambient hydraulic gradients, duration of various experimental phases, hydraulic injection pressure and parameter identification possibilities. Particular emphasis has been placed on the use of the dilution probe as an experimental device for SWIW, although the scoping results also should be considered applicable to any experimental equipment approach. The results from the scoping calculations indicate that SWIW tests using the dilution probe are feasible under the required experimental and site requirements for the forthcoming site investigations programme. The characteristic flow reversibility feature inherent in SWIW tests causes some differences compared with cross-hole tracer tests. Advective parameters (i.e. mobile porosity, dispersivity) are generally more difficult to identify/estimate and the same may also be said about equilibrium sorption. Time-dependent processes, on the other hand, generally benefit from the flow reversibility, in principle even in the presence of heterogeneity. However, it may not always be possible to identify time-dependent processes, such as matrix diffusion, for expected conditions in Swedish bedrock. Experimental aims may be allowed to vary depending on the specific conditions (transmissivity, hydraulic gradient, etc.) in the tested borehole section.

  8. Geometric Reconstruction of Bedrock and Overlying Recent Deposits In An Intra-mountain Basin: The Clusone Basin (southern Alps, Italy)

    Science.gov (United States)

    Caielli, G.; Berra, F.

    Regione Lombardia (Direzione Generale Territorio e Urbanistica) and the National Research Council (CNR-IDPA Milano) acquired seismic reflection profiles in the Clu- sone basin (Middle Val Seriana, Southern Alps). In the study area, the bedrock is rep- resented by late Triassic carbonate units (Formazione di Castro, Dolomia Principale and coeval basinal facies, bordered northward by an important alpine fault) covered by a large amount of recent deposits that covers an area of more than 10 km2, with a maximum thickness of more than two hundreds meters, as documented by available well data. The aim of the seismic prospecting was to identify the sediments layering and the rock basement depth. The acquisition parameters were as follows: group in- terval 10 m; shot interval 5 m; geophone frequency 14 Hz; sample rate 1 ms; record length 2 s, energy source hydrapulse. The cable, with 120 channels, remained dur- ing all the experiment allowing reflection/refraction events acquisition. The data were processed by a standard procedure using PROMAX and SUNT5 processing codes. The statics were calculated starting from the refracted first arrivals using a two layer inversion based on least square optimisation. Standard seismic reflection processing was applied to obtain reflection images and it was integrated with seismic refraction data inversion. Seismic profiles allow to reconstruct both the main reflectors in the recent deposits and the geometry of the bedrock. The first results document a complex history in the drainage patterns of the Clusone basin, allowing to identify, in an intra- mountain basin, drainage directions that in some cases are different from the ones that can be observed today. The integration of well data and seismic profiles in this study of an intra-mountain basin allows on one side the identification of the bedrock geome- tries and, on the other, gives constrains for the reconstruction of the geomorphologic evolution of a sector of a mountain chain.

  9. Lithological effects in soil formation and soil slips on weathering-limited slopes underlain by granitic bedrocks in Japan

    OpenAIRE

    Wakatsuki, Tsuyoshi; Matsukura, Yukinori

    2008-01-01

    Soil slips occur every few years due to heavy rains on biotite granite (Gb) and hornblende biotite granite (Ghb) slopes in the Taga Mountains, Ibaraki Prefecture, Japan. The occurrence density of soil slips per unit area is 2.7 times greater in the Gb slopes than that in Ghb slopes. We examined the chemical, mineral, physical, and mechanical properties of two soil profiles on soil-slip scars in these slopes to study the effect of bedrock mineral composition on the density of soil slips. For a...

  10. Field measurements of incision rates following bedrock exposure: Implications for process controls on the long profiles of valleys cut by rivers and debris flows

    Science.gov (United States)

    Stock, Jonathan D.; Montgomery, David R.; Collins, Brian D.; Dietrich, William E.; Sklar, Leonard

    2005-01-01

    Until recently, published rates of incision of bedrock valleys came from indirect dating of incised surfaces. A small but growing literature based on direct measurement reports short-term bedrock lowering at geologically unsustainable rates. We report observations of bedrock lowering from erosion pins monitored over 1–7 yr in 10 valleys that cut indurated volcanic and sedimentary rocks in Washington, Oregon, California, and Taiwan. Most of these channels have historically been stripped of sediment. Their bedrock is exposed to bed-load abrasion, plucking, and seasonal wetting and drying that comminutes hard, intact rock into plates or equant fragments that are removed by higher flows. Consequent incision rates are proportional to the square of rock tensile strength, in agreement with experimental results of others. Measured rates up to centimeters per year far exceed regional long-term erosion-rate estimates, even for apparently minor sediment-transport rates. Cultural artifacts on adjoining strath terraces in Washington and Taiwan indicate at least several decades of lowering at these extreme rates. Lacking sediment cover, lithologies at these sites lower at rates that far exceed long-term rock-uplift rates. This rate disparity makes it unlikely that the long profiles of these rivers are directly adjusted to either bedrock hardness or rock-uplift rate in the manner predicted by the stream power law, despite the observation that their profiles are well fit by power-law plots of drainage area vs. slope. We hypothesize that the threshold of motion of a thin sediment mantle, rather than bedrock hardness or rock-uplift rate, controls channel slope in weak bedrock lithologies with tensile strengths below ∼3–5 MPa. To illustrate this hypothesis and to provide an alternative interpretation for power-law plots of area vs. slope, we combine Shields' threshold transport concept with measured hydraulic relationships and downstream fining rates. In contrast to fluvial

  11. A strategy for delineating the area of ground-water contribution to wells completed in fractured bedrock aquifers in Pennsylvania

    Science.gov (United States)

    Risser, D.W.; Barton, G.J.

    1995-01-01

    Delineating a contributing area to a well completed in a fractured bedrock aquifer in Pennsylvania is difficult because the hydrogeologic characteristics of fractured rocks are extremely complex. Because of this complexity, a single method or technique to delineate a contributing area will not be applicable for all wells completed in fractured-bedrock aquifers. Therefore, a strategy for refining the understanding of boundary conditions and major heterogeneities that control ground-water flow and sources of water to a supply well is suggested. The strategy is based on developing and refining a conceptual model for the sources of water to the well. Specifically, the strategy begins with an initial conceptual model of the ground-water-flow system, then requires the collection of hydrogeologic information to refine the conceptual model in a stepwise manner from one or more of sic categories: (1) hydrogeologic mapping, (2) water-level and streamflow measurements, (3) geochemistry, (4) geophysics and borehole flowmetering, (5) aquifer testing, and (6) tracer testing. During the refinement process, the applicability of treating the fratured-rock aquifer as a hydrologic continuum is evaluated, and the contributing area is delineated. Choice of the method used to delineate the contributing area is less important than insuring that the method is consistent with the refined conceptual model. By use of such a strategy, the improved understanding of the ground-water-flow system will lead to a technically defensible delineation of the contributing area.

  12. Relations of As concentrations among groundwater, soil, and bedrock in Chungnam, Korea: implications for As mobilization in groundwater according to the As-hosting mineral change.

    Science.gov (United States)

    Kim, Kangjoo; Kim, Seok-Hwi; Jeong, Gi Young; Kim, Rak-Hyeon

    2012-01-15

    Arsenic (As) concentrations and As-bearing minerals in bedrock and soil, and their relations with groundwater concentrations were investigated in a small agricultural area of Korea. The As concentration of the bedrock shows a wide variation (<0.5-3990 mg/kg) and is well correlated with that in the contacting groundwaters (23-178 μg/L). Soils, the weathering product of bedrock, show the lower and more dispersed As concentrations (8.8-387 mg/kg) than the bedrock. But the soil As concentrations are very high relative to those reported from other areas. The As concentrations in the shallow groundwaters are comparatively low (<20 μg/L) and are independent of the soil concentration. Arsenopyrite is the major As-bearing mineral in the bedrock and its oxidation controls the As levels in deep groundwater. In contrast, As mostly resides in soil as Fe-(hydr)oxide-bound forms. Due to low pH and oxidizing redox condition, the release of As from Fe-(hydr)oxides is largely suppressed, and the shallow groundwater shows low As concentrations generally satisfying the drinking water limit. However, it is suggested that the disturbance of soil geochemical conditions by land use changes would cause a serious As contamination of the shallow groundwaters.

  13. Geology, Bedrock, Drill hole locations, most with samples, for oil and gas exploratory wells, municipal water wells, stratigraphic test holes, and mineral exploration holes. Note that bedrock samples may not be available for all drill holes., Published in 1998, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 1998. It is described as...

  14. Geology, Bedrock, Bedrock geologic map of the NPS Blue Ridge Parkway corridor. Majority of central and southern segments completed with entire project completed by October 2008., Published in 2004, 1:12000 (1in=1000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from Field Survey/GPS information as of 2004. It is described as...

  15. Geology, Bedrock, Data contains 10 foot elevation contours (1 foot in some areas) showing the approximate bedrock surface elevation within McLain State Park, Houghton, County, Michigan. Contours were generated with the Surfer 12 software package using soil test borings and, Published in 2014, Not Applicable scale, Michigan Coastal Zone Management Program.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at Not Applicable scale, was produced all or in part from Field Survey/GPS information as of 2014. The source is Michigan...

  16. Geology, Bedrock, Bedrock Geologic Map of the Western Portion of the Rock Mount 100K Quadrangle, Nash, Wilson, and Edgecombe Counties, North Carolina (1:50,000 Scale), Published in 2004, 1:100000 (1in=8333ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:100000 (1in=8333ft) scale, was produced all or in part from Field Observation information as of 2004. It is described...

  17. Structure and geological evolution of the bedrock at southern Satakunta, SW Finland

    Energy Technology Data Exchange (ETDEWEB)

    Paulamaeki, S.; Paananen, M.; Elo, S. [Geological Survey of Finland (Finland)

    2002-02-01

    The southern Satakunta area lies on the west coast of Finland, mainly covering the mainland (with main towns Pori and Rauma), but also including the coastal archipelago and part of the Bothnian Sea. Near the centre of the area lies the island of Olkiluoto, on which Finland's site for a deep repository for spent nuclear fuel is located. The purpose of the present report is to compile and interpret all available geological and geophysical data relevant to understanding the regional geological setting of the Olkiluoto site. The area described is covered by four 1:100 000 scale geological map sheets, published by the Geological Survey of Finland, which, together with low-altitude aeromagnetic maps, provide the basis for a new 1:250 000 geological map compilation. This shows that the bedrock of southern Satakunta can be subdivided into three main zones: a pelitic migmatite belt in the southwest, a central, NW-SE trending area of sandstone, and a psammitic migmatite belt in the northeast. The migmatite belts formed during the Svecofennian orogeny, 1900-1800 Ma ago (Palaeoproterozoic). The sandstone area is the remnant of an alluvial basin, preserved now in a NW-SE trending graben, bounded on both sides by normal fault zones. The sandstones are thought to be at least 1400-1300 Ma old (Mesoproterozoic), and they are cut by Postjotnian olivine diabase dykes, 1270-1250 Ma in age. The Svecofennian migmatite belts show a complex history of formation, with various phases of anatexis/metamorphism, deformation and intrusion. In the pelitic migmatite belt, in which the Olkiluoto site is situated, four phases of ductile deformation (D-D4) and two phases of regional highT/lowP metamorphism and migmatite formation can be recognised, together with synorogenic (tonalite, granodiotite) and late orogenic ( potassium granite) intrusions. Subsequently, this very heterogeneous complex was intruded by anorogenic rapakivi granites, with ages 1580-1550 Ma. One pluton, the Eurajoki stock

  18. Structure and geological evolution of the bedrock at southern Satakunta, SW Finland

    Energy Technology Data Exchange (ETDEWEB)

    Paulamaeki, S.; Paananen, M.; Elo, S. [Geological Survey of Finland (Finland)

    2002-02-01

    The southern Satakunta area lies on the west coast of Finland, mainly covering the mainland (with main towns Pori and Rauma), but also including the coastal archipelago and part of the Bothnian Sea. Near the centre of the area lies the island of Olkiluoto, on which Finland's site for a deep repository for spent nuclear fuel is located. The purpose of the present report is to compile and interpret all available geological and geophysical data relevant to understanding the regional geological setting of the Olkiluoto site. The area described is covered by four 1:100 000 scale geological map sheets, published by the Geological Survey of Finland, which, together with low-altitude aeromagnetic maps, provide the basis for a new 1:250 000 geological map compilation. This shows that the bedrock of southern Satakunta can be subdivided into three main zones: a pelitic migmatite belt in the southwest, a central, NW-SE trending area of sandstone, and a psammitic migmatite belt in the northeast. The migmatite belts formed during the Svecofennian orogeny, 1900-1800 Ma ago (Palaeoproterozoic). The sandstone area is the remnant of an alluvial basin, preserved now in a NW-SE trending graben, bounded on both sides by normal fault zones. The sandstones are thought to be at least 1400-1300 Ma old (Mesoproterozoic), and they are cut by Postjotnian olivine diabase dykes, 1270-1250 Ma in age. The Svecofennian migmatite belts show a complex history of formation, with various phases of anatexis/metamorphism, deformation and intrusion. In the pelitic migmatite belt, in which the Olkiluoto site is situated, four phases of ductile deformation (D-D4) and two phases of regional highT/lowP metamorphism and migmatite formation can be recognised, together with synorogenic (tonalite, granodiotite) and late orogenic ( potassium granite) intrusions. Subsequently, this very heterogeneous complex was intruded by anorogenic rapakivi granites, with ages 1580-1550 Ma. One pluton, the Eurajoki stock

  19. Comparison of mineral weathering and biomass nutrient uptake in two small forested watersheds underlain by quartzite bedrock, Catoctin Mountain, Maryland, USA

    Science.gov (United States)

    Rice, Karen; Price, Jason R.

    2014-01-01

    To quantify chemical weathering and biological uptake, mass-balance calculations were performed on two small forested watersheds located in the Blue Ridge Physiographic Province in north-central Maryland, USA. Both watersheds, Bear Branch (BB) and Fishing Creek Tributary (FCT), are underlain by relatively unreactive quartzite bedrock. Such unreactive bedrock and associated low chemical-weathering rates offer the opportunity to quantify biological processes operating within the watershed. Hydrologic and stream-water chemistry data were collected from the two watersheds for the 9-year period from June 1, 1990 to May 31, 1999. Of the two watersheds, FCT exhibited both higher chemical-weathering rates and biomass nutrient uptake rates, suggesting that forest biomass aggradation was limited by the rate of chemical weathering of the bedrock. Although the chemical-weathering rate in the FCT watershed was low relative to the global average, it masked the influence of biomass base-cation uptake on stream-water chemistry. Any differences in bedrock mineralogy between the two watersheds did not exert a significant influence on the overall weathering stoichiometry. The difference in chemical-weathering rates between the two watersheds is best explained by a larger proportion of reactive phyllitic layers within the bedrock of the FCT watershed. Although the stream gradient of BB is about two-times greater than that of FCT, its influence on chemical weathering appears to be negligible. The findings of this study support the biomass nutrient uptake stoichiometry of K1.0Mg1.1Ca0.97 previously determined for the study site. Investigations of the chemical weathering of relatively unreactive quartzite bedrock may provide insight into critical zone processes.

  20. Determination of Bedrock Variations and S-wave Velocity Structure in the NW part of Turkey for Earthquake Hazard Mitigation

    Science.gov (United States)

    Ozel, A. O.; Arslan, M. S.; Aksahin, B. B.; Genc, T.; Isseven, T.; Tuncer, M. K.

    2015-12-01

    Tekirdag region (NW Turkey) is quite close to the North Anatolian Fault which is capable of producing a large earthquake. Therefore, earthquake hazard mitigation studies are important for the urban areas close to the major faults. From this point of view, integration of different geophysical methods has important role for the study of seismic hazard problems including seismotectonic zoning. On the other hand, geological mapping and determining the subsurface structure, which is a key to assist management of new developed areas, conversion of current urban areas or assessment of urban geological hazards can be performed by integrated geophysical methods. This study has been performed in the frame of a national project, which is a complimentary project of the cooperative project between Turkey and Japan (JICA&JST), named as "Earthquake and Tsunami Disaster Mitigation in the Marmara Region and Disaster Education". With this principal aim, this study is focused on Tekirdag and its surrounding region (NW of Turkey) where some uncertainties in subsurface knowledge (maps of bedrock depth, thickness of quaternary sediments, basin geometry and seismic velocity structure,) need to be resolved. Several geophysical methods (microgravity, magnetic and single station and array microtremor measurements) are applied and the results are evaluated to characterize lithological changes in the region. Array microtremor measurements with several radiuses are taken in 30 locations and 1D-velocity structures of S-waves are determined by the inversion of phase velocities of surface waves, and the results of 1D structures are verified by theoretical Rayleigh wave modelling. Following the array measurements, single-station microtremor measurements are implemented at 75 locations to determine the predominant frequency distribution. The predominant frequencies in the region range from 0.5 Hz to 8 Hz in study area. On the other hand, microgravity and magnetic measurements are performed on

  1. High-Resolution Flow Logging for Hydraulic Characterization of Boreholes and Aquifer Flow Zones at Contaminated Bedrock Sites

    Science.gov (United States)

    Williams, J. H.; Johnson, C. D.; Paillet, F. L.

    2004-05-01

    In the past, flow logging was largely restricted to the application of spinner flowmeters to determine flow-zone contributions in large-diameter production wells screened in highly transmissive aquifers. Development and refinement of tool-measurement technology, field methods, and analysis techniques has greatly extended and enhanced flow logging to include the hydraulic characterization of boreholes and aquifer flow zones at contaminated bedrock sites. State-of-the-art in flow logging will be reviewed, and its application to bedrock-contamination investigations will be presented. In open bedrock boreholes, vertical flows are measured with high-resolution flowmeters equipped with flexible rubber-disk diverters fitted to the nominal borehole diameters to concentrate flow through the measurement throat of the tools. Heat-pulse flowmeters measure flows in the range of 0.05 to 5 liters per minute, and electromagnetic flowmeters measure flows in the range of 0.3 to 30 liters per minute. Under ambient and low-rate stressed (either extraction or injection) conditions, stationary flowmeter measurements are collected in competent sections of the borehole between fracture zones identified on borehole-wall images. Continuous flow, fluid-resistivity, and temperature logs are collected under both sets of conditions while trolling with a combination electromagnetic flowmeter and fluid tool. Electromagnetic flowmeters are used with underfit diverters to measure flow rates greater than 30 liters per minute and suppress effects of diameter variations while trolling. A series of corrections are applied to the flow-log data to account for the zero-flow response, bypass, trolling, and borehole-diameter biases and effects. The flow logs are quantitatively analyzed by matching simulated flows computed with a numerical model to measured flows by varying the hydraulic properties (transmissivity and hydraulic head) of the flow zones. Several case studies will be presented that demonstrate

  2. Mineralogical sources of groundwater fluoride in Archaen bedrock/regolith aquifers: Mass balances from southern India and north-central Sri Lanka

    Directory of Open Access Journals (Sweden)

    B.M. Hallett

    2015-09-01

    New hydrological insights for the region: An estimate of weathering duration for the in situ regolith in Andhra Pradesh, 250–380 Ka, is close to a previous estimate for southern India. Partial or total destruction of the primary F-bearing bedrock minerals and consistent depletion of F in the remnant minerals result in a much reduced total F content in the regolith. Leaching experiments and field relationships, however, indicate a greater potential for F mobilisation to groundwater from the regolith than the bedrock. Schemes for managed aquifer recharge should beware the risk of mobilising additional F to groundwater.

  3. Water resources of Rockland County, New York, 2005-07, with emphasis on the Newark Basin Bedrock Aquifer

    Science.gov (United States)

    Heisig, Paul M.

    2011-01-01

    Concerns over the state of water resources in Rockland County, NY, prompted an assessment of current (2005-07) conditions. The investigation included a review of all water resources but centered on the Newark basin aquifer, a fractured-bedrock aquifer over which nearly 300,000 people reside. Most concern has been focused on this aquifer because of (1) high summer pumping rates, with occasional entrained-air problems and an unexplained water-level decline at a monitoring well, (2) annual withdrawals that have approached or even exceeded previous estimates of aquifer recharge, and (3) numerous contamination problems that have caused temporary or long-term shutdown of production wells. Public water supply in Rockland County uses three sources of water in roughly equal parts: (1) the Newark basin sedimentary bedrock aquifer, (2) alluvial aquifers along the Ramapo and Mahwah Rivers, and (3) surface waters from Lake DeForest Reservoir and a smaller, new reservoir supply in the Highlands part of the county. Water withdrawals from the alluvial aquifer in the Ramapo River valley and the Lake DeForest Reservoir are subject to water-supply application permits that stipulate minimum flows that must be maintained downstream into New Jersey. There is a need, therefore, at a minimum, to prevent any loss of the bedrock-aquifer resource--to maintain it in terms of both sustainable use and water-quality protection. The framework of the Newark basin bedrock aquifer included characterization of (1) the structure and fracture occurrence associated with the Newark basin strata, (2) the texture and thickness of overlying glacial and alluvial deposits, (3) the presence of the Palisades sill and associated basaltic units on or within the Newark basin strata, and (4) the streams that drain the aquifer system. The greatest concern regarding sustainability of groundwater resources is the aquifer response to the seasonal increase in pumping rates from May through October (an average increase

  4. GPS monitoring of bedrock stability at Olkiluoto nuclear waste disposal site in Finland from 1996 to 2012

    Science.gov (United States)

    Nyberg, S.; Kallio, U.; Koivula, H.

    2013-09-01

    The Finnish Geodetic Institute has studied crustal deformations at Olkiluoto nuclear waste disposal site since mid-90's. Biannual GPS measurement has been carried out in two local GPS networks. This paper analyses the GPS data processing effects on the coordinate solutions and presents the results of GPS monitoring from 1996 to 2012. The GPS data was processed using Bernese GPS Software 5.0. The GPS data processing and baseline analysis showed a 1.0 mm (max RMS) level agreement of observation and high bedrock stability in the area. Most of the horizontal trends were smaller than 0.1 mm/a. The troposphere estimation strategy had a clear effect on the horizontal trends at some sites. The strain rates were all very small, but we could detect motions near the Olkiluoto permanent station.

  5. Map showing depth to bedrock of the Tacoma and part of the Centralia 30' x 60' quadrangles, Washington

    Science.gov (United States)

    Buchanan-Banks, Jane M.; Collins, Donley S.

    1994-01-01

    The heavily populated Puget Sound region in the State of Washington has experienced moderate to large earthquakes in the recent past (Nuttli, 1952; Mullineaux and others, 1967). Maps showing thickness of unconsolidated sedimentary deposits are useful aids in delineating areas where damage to engineered structures can result from increased shaking resulting from these earthquakes. Basins containing thick deposits of unconsolidated materials can amplify earthquakes waves and cause far more damage to structures than the same waves passing through bedrock (Singh and others, 1988; Algermissen and others, 1985). Configurations of deep sedimentary basins can also cause reflection and magnification of earthquake waves in ways still not fully understood and presently under investigation (Frankel and Vidale, 1992).

  6. Establishing time-dependent model of deformation modulus caused by bedrock excavation rebound by inverse analysis method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Rock rebound relaxation deformation,or even rock burst,caused by the excavation of dam base and abutment or high rock slope affects their stability and results in the fall of mechanical properties of the rock.So an inverse analysis method was proposed in this paper to establish the time-dependent model of deformation modulus caused by excavation rebound.The basic principle is based on the combination of observed data of the excavation rebound deformation of dam abutment or rock slope,and the calculated rebound deformation by FEM under ground stress at the corresponding time in the excavation process.The norm of the residuals of observed data and calculated data are taken as the objective function.Accordingly,the time-dependent model of bedrock deformation modulus can be established.The method displays its significance in the design of excavation,construction and operation management of dam base and high slope.

  7. Estimation of microbial metabolism and co-occurrence patterns in fracture groundwaters of deep crystalline bedrock at Olkiluoto, Finland

    Directory of Open Access Journals (Sweden)

    M. Bomberg

    2015-08-01

    Full Text Available The microbial diversity in oligotrophic isolated crystalline Fennoscandian Shield bedrock fracture groundwaters is great but the core community has not been identified. Here we characterized the bacterial and archaeal communities in 12 water conductive fractures situated at depths between 296 and 798 m by high throughput amplicon sequencing using the Illumina HiSeq platform. The great sequencing depth revealed that up to 95 and 99 % of the bacterial and archaeal communities, respectively, were composed of only a few common species, i.e. the core microbiome. However, the remaining rare microbiome contained over 3 and 6 fold more bacterial and archaeal taxa. Several clusters of co-occurring rare taxa were identified, which correlated significantly with physicochemical parameters, such as salinity, concentration of inorganic or organic carbon, sulphur, pH and depth. The metabolic properties of the microbial communities were predicted using PICRUSt. The rough prediction showed that the metabolic pathways included commonly fermentation, fatty acid oxidation, glycolysis/gluconeogenesis, oxidative phosphorylation and methanogenesis/anaerobic methane oxidation, but carbon fixation through the Calvin cycle, reductive TCA cycle and the Wood-Ljungdahl pathway was also predicted. The rare microbiome is an unlimited source of genomic functionality in all ecosystems. It may consist of remnants of microbial communities prevailing in earlier conditions on Earth, but could also be induced again if changes in their living conditions occur. In this study only the rare taxa correlated with any physicochemical parameters. Thus these microorganisms can respond to environmental change caused by physical or biological factors that may lead to alterations in the diversity and function of the microbial communities in crystalline bedrock environments.

  8. Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA

    Science.gov (United States)

    Yang, Qiang; Culbertson, Charles W.; Nielsen, Martha G.; Schalk, Charles W.; Johnson, Carole D.; Marvinney, Robert G.; Stute, Martin; Zheng, Yan

    2014-01-01

    To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 µg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70–100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93–99%) in particulates (>0.45 µm). These particulates and those settled after a 16-day batch experiment contain 560–13,000 mg/kg of As and 14–35% weight/weight of Fe. As/Fe ratios (2.5–20 mmole/mole) and As partitioning ratios (adsorbed/dissolved [As], 20,000–100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1,300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ18O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater. PMID:24842411

  9. Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA.

    Science.gov (United States)

    Yang, Qiang; Culbertson, Charles W; Nielsen, Martha G; Schalk, Charles W; Johnson, Carole D; Marvinney, Robert G; Stute, Martin; Zheng, Yan

    2015-02-01

    To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70-100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93-99%) in particulates (>0.45 μm). These particulates and those settled after a 16-day batch experiment contain 560-13,000 mg/kg of As and 14-35% weight/weight of Fe. As/Fe ratios (2.5-20 mmol/mol) and As partitioning ratios (adsorbed/dissolved [As], 20,000-100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ(18)O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes the oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater.

  10. Geomorphology of the Alluvial Sediments and Bedrock in an Intermontane Basin: Application of Variogram Modeling to Electrical Resistivity Soundings

    Science.gov (United States)

    Khan, Adnan Ahmad; Farid, Asam; Akhter, Gulraiz; Munir, Khyzer; Small, James; Ahmad, Zulfiqar

    2016-05-01

    The study describes a methodology used to integrate legacy resistivity data with limited geological data in order to build three-dimensional models of the near subsurface. Variogram analysis and inversion techniques more typically found in the petroleum industry are applied to a set of 1D resistivity data taken from electrical surveys conducted in the 1980s. Through careful integration with limited geological data collected from boreholes and outcrops, the resultant model can be visualized in three dimensions to depict alluvium layers as lithological and structural units within the bedrock. By tuning the variogram parameters to account for directionality, it is possible to visualize the individual lithofacies and geomorphological features in the subsurface. In this study, an electrical resistivity data set collected as part of a groundwater study in an area of the Peshawar basin in Pakistan has been re-examined. Additional lithological logs from boreholes throughout the area have been combined with local outcrop information to calibrate the data. Tectonic activity during the Himalayan orogeny has caused uplift in the area and generated significant faulting in the bedrock resulting in the formation of depressions which are identified by low resistivity values representing clays. Paleo-streams have reworked these clays which have been eroded and replaced by gravel-sand facies along paleo-channels. It is concluded that the sediments have been deposited as prograding fan-shaped bodies and lacustrine deposits with interlayered gravel-sand and clay-silt facies. The Naranji area aquifer system has thus been formed as a result of local tectonic activity with fluvial erosion and deposition and is characterized by coarse sediments with high electrical resistivities.

  11. Estimation of microbial metabolism and co-occurrence patterns in fracture groundwaters of deep crystalline bedrock at Olkiluoto, Finland

    Science.gov (United States)

    Bomberg, M.; Lamminmäki, T.; Itävaara, M.

    2015-08-01

    The microbial diversity in oligotrophic isolated crystalline Fennoscandian Shield bedrock fracture groundwaters is great but the core community has not been identified. Here we characterized the bacterial and archaeal communities in 12 water conductive fractures situated at depths between 296 and 798 m by high throughput amplicon sequencing using the Illumina HiSeq platform. The great sequencing depth revealed that up to 95 and 99 % of the bacterial and archaeal communities, respectively, were composed of only a few common species, i.e. the core microbiome. However, the remaining rare microbiome contained over 3 and 6 fold more bacterial and archaeal taxa. Several clusters of co-occurring rare taxa were identified, which correlated significantly with physicochemical parameters, such as salinity, concentration of inorganic or organic carbon, sulphur, pH and depth. The metabolic properties of the microbial communities were predicted using PICRUSt. The rough prediction showed that the metabolic pathways included commonly fermentation, fatty acid oxidation, glycolysis/gluconeogenesis, oxidative phosphorylation and methanogenesis/anaerobic methane oxidation, but carbon fixation through the Calvin cycle, reductive TCA cycle and the Wood-Ljungdahl pathway was also predicted. The rare microbiome is an unlimited source of genomic functionality in all ecosystems. It may consist of remnants of microbial communities prevailing in earlier conditions on Earth, but could also be induced again if changes in their living conditions occur. In this study only the rare taxa correlated with any physicochemical parameters. Thus these microorganisms can respond to environmental change caused by physical or biological factors that may lead to alterations in the diversity and function of the microbial communities in crystalline bedrock environments.

  12. Groundtruthing and potential for predicting acid deposition impacts in headwater streams using bedrock geology, GIS, angling, and stream chemistry.

    Science.gov (United States)

    Kirby, C S; McInerney, B; Turner, M D

    2008-04-15

    Atmospheric acid deposition is of environmental concern worldwide, and the determination of impacts in remote areas can be problematic. Rainwater in central Pennsylvania, USA, has a mean pH of approximately 4.4. Bedrock varies dramatically in its ability to neutralize acidity. A GIS database simplified reconnaissance of non-carbonate bedrock streams in the Valley and Ridge Province and identified potentially chronically impacted headwater streams, which were sampled for chemistry and brook trout. Stream sites (n=26) that originate in and flow through the Tuscarora had a median pH of 5.0 that was significantly different from other formations. Shawangunk streams (n=6) and non-Tuscarora streams (n=20) had a median pH of 6.0 and 6.3, respectively. Mean alkalinity for non-Tuscarora streams (2.6 mg/L CaCO(3)) was higher than the mean for Tuscarora streams (0.5 mg/L). Lower pH and alkalinity suggest that the buffering capability of the Tuscarora is inferior to that of adjacent sandstones. Dissolved aluminum concentrations were much higher for Tuscarora streams (0.2 mg/L; approximately the lethal limit for brook trout) than for non-Tuscarora streams (0.03 mg/L) or Shawangunk streams (0.02 mg/L). Hook-and-line methods determined the presence/absence of brook trout in 47 stream reaches with suitable habitat. Brook trout were observed in 21 of 22 non-Tuscarora streams, all 6 Shawangunk streams, and only 9 of 28 Tuscarora stream sites. Carefully-designed hook-and-line sampling can determine the presence or absence of brook trout and help confirm biological impacts of acid deposition. 15% of 334 km of Tuscarora stream lengths are listed as "impaired" due to atmospheric deposition by the Pennsylvania Department of Environmental Protection. 65% of the 101 km of Tuscarora stream lengths examined in this study were impaired.

  13. 3H/3He ages, CFC ages and He isotopes in the fractured bedrock of the Mirror Lake Basin, NH

    Science.gov (United States)

    Torgersen, T.; Stute, M.; Drenkard, S.; Schlosser, P.; Busenberg, E.; Plummer, N.; Shapiro, A.

    2001-05-01

    Tritium/3He and CFC (chlorofluorocarbon) analyses were conducted on groundwater samples from the fractured bedrock and the overlying drift of Mirror Lake watershed in central New Hampshire. These groundwaters have a significant terrigenic helium component that increases with depth. The 3He/4He ratio of the terrigenic helium indicates the presence of two groundwater types. Where terrigenic sources of 3He are no more than 10 times the 3He signal produced by 3H decay (tritiogenic 3He), 3H/3He ages can be calculated. However, drift age profiles cannot be interpreted as recharge rates because the 2D, 2-layer coupled bedrock/drift system violates the simple homogeneous 1D conditions necessary to interpret age profiles as recharge rates. Secondly, while some agreement is seen between 3H/3He ages and CFC ages, the reconstruction of the 1963 'bomb' 3H peak yields a maximum that is significantly less (1/10) than expected. This apparent loss of 3H is cannot be attributed to dispersion or dual hydraulic conductivity but is consistent with the models of dual porosity. The data also demonstrate that '3H/3Hetri calibrated 4He ages' are invalid and cannot be used to extend the 'age' information contained in He isotope analysis. The results of this study again demonstrate that tracers have an important role in the calibration and definition of flow models for complex groundwater systems. However, it is suggested that tracers should be routinely inserted into groundwater flow models to determine (I) which tracers are best suited to the problem and (ii) where to sample for tracers to best differentiate among model possibilities as well as which parameters constitute the best descriptions of the groundwater system. Such coupling of multiple tracers and flow models at the earliest stages will provide the highest probability for determining the best flow model.

  14. Faulting and erosion in the Argentine Precordillera during changes in subduction regime: Reconciling bedrock cooling and detrital records

    Science.gov (United States)

    Fosdick, Julie C.; Carrapa, Barbara; Ortíz, Gustavo

    2015-12-01

    The Argentine Precordillera is an archetypal retroarc fold-and-thrust belt that records tectonics associated with changing subduction regimes. The interactions between exhumation and faulting in the Precordillera were investigated using apatite and zircon (U-Th-Sm)/He and apatite fission track thermochronometry from the Precordillera and adjacent geologic domains. Inverse modeling of thermal histories constrains eastward in-sequence rock cooling associated with deformation and erosion from 18 to 2 Ma across the Central Precordillera tracking thrusting during this time. The youngest AHe ages (5-2 Ma) and highest erosion rates are located in the eastern and western extremities of the Precordillera and indicate that recent denudation is concentrated at its structural boundaries. Moreover, synchronous rapid Pliocene cooling of the Frontal Cordillera, Eastern Precordillera, and Sierra del Valle Fértil was coeval with initiation of basement-involved faulting in the foreland. Detrital zircon U-Pb geochronology from the ca. 16-8.1 Ma Bermejo foreland basin strata suggests fluvial connectivity westward beyond the Frontal Cordillera to the Main Cordillera and Coast Range followed by an important shift in sediment provenance at ca. 10 Ma. At this time, we suggest that a substantial decrease in Permo-Triassic igneous sources in the Frontal Cordillera and concurrent increase in recycled zircons signatures of Paleozoic strata are best explained by uplift and erosion of the Precordillera during widening of the thrust-belt. Bedrock thermochronology and modeling indicate a 2-6 Myr lag time between faulting-related cooling in the hinterland and the detrital record of deformation in the foreland basin, suggesting that for tectonically active semi-arid settings, bedrock cooling may be more sensitive to onset of faulting. We suggest that high erosion rates in the Frontal Cordillera and Eastern Precordillera are associated with increased interplate coupling during shallowing of the

  15. Impacts of forest harvesting on mobilization of Hg and MeHg in drained peatland forests on black schist or felsic bedrock.

    Science.gov (United States)

    Ukonmaanaho, Liisa; Starr, Mike; Kantola, Marjatta; Laurén, Ari; Piispanen, Juha; Pietilä, Heidi; Perämäki, Paavo; Merilä, Päivi; Fritze, Hannu; Tuomivirta, Tero; Heikkinen, Juha; Mäkinen, Jari; Nieminen, Tiina M

    2016-04-01

    Forest harvesting, especially when intensified harvesting method as whole-tree harvesting with stump lifting (WTHs) are used, may increase mercury (Hg) and methylmercury (MeHg) leaching to recipient water courses. The effect can be enhanced if the underlying bedrock and overburden soil contain Hg. The impact of stem-only harvesting (SOH) and WTHs on the concentrations of Hg and MeHg as well as several other variables in the ditch water was studied using a paired catchment approach in eight drained peatland-dominated catchments in Finland (2008-2012). Four of the catchments were on felsic bedrock and four on black schist bedrock containing heavy metals. Although both Hg and MeHg concentrations increased after harvesting in all treated sites according to the randomized intervention analyses (RIAs), there was only a weak indication of a harvest-induced mobilization of Hg and MeHg into the ditches. Furthermore, no clear differences between WTHs and SOH were found, although MeHg showed a nearly significant difference (p = 0.06) between the harvesting regimes. However, there was a clear bedrock effect, since the MeHg concentrations in the ditch water were higher at catchments on black schist than at those on felsic bedrock. The pH, suspended solid matter (SSM), dissolved organic carbon (DOC), and iron (Fe) concentrations increased after harvest while the sulfate (SO4-S) concentration decreased. The highest abundances of sulfate-reducing bacteria (SRB) were found on the sites with high MeHg concentrations. The biggest changes in ditch water concentrations occurred first 2 years after harvesting.

  16. Sediment Dynamics and the Burial and Exhumation of Bedrock Reefs as Elucidated by High-resolution Repetitive Sonar Surveys: Northern Monterey Bay, CA

    Science.gov (United States)

    Storlazzi, C. D.; Fregoso, T. A.; Golden, N. E.; Finlayson, D. P.

    2011-12-01

    Two high-resolution bathymetric and acoustic backscatter sonar surveys were conducted along the energetic emergent inner shelf of northern Monterey Bay, CA, USA, in the fall of 2005 and the spring of 2006 to determine the impact of winter storm waves, beach erosion, and river floods on biologically-important bedrock reef habitats. The surveys extended from water depths of 4 m to 22 m and covered an area of 3.14 km2, of which 45.8% was bedrock, gravel, and coarse-grained sand and 54.2% was fine-grained sand. Our analysis of the bathymetric and acoustic backscatter data demonstrates that during the 6 months between surveys, 11.4% of the study area was buried by fine-grained sand while erosion exposed of bedrock or coarse-grained sand over 26.5% of the study area. The probability of burial decreased with increasing water depth and rugosity; the probability of exhumation increased with increasing seabed slope and rugosity. Much of the detected change was at the boundary between bedrock and unconsolidated sediment due to burial or exhumation of bedrock. In a number of cases, however, the change in seabed character was apparently due to fluctuations in sediment grain size, where scour exposed what appeared to be an underlying coarser-grained lag or fine-grained sand buried coarser-grained sand. These findings suggest that, in some places, (a) single acoustic surveys typically employed for geologic characterization and/or habitat mapping may not adequately characterize the geomorphology and sedimentologic nature of rocky, energetic inner shelves, and (b) burial and exhumation likely play a role in the life history of the numerous organisms that inhabit these reefs and thus information on the frequency and magnitude of such processes may better constrain our understanding of physical controls on benthic species' distribution patterns.

  17. Lithologic and hydrologic controls of mixed alluvial-bedrock channels in flood-prone fluvial systems: Bankfull and macrochannels in the Llano River watershed, central Texas, USA

    Science.gov (United States)

    Heitmuller, Franklin T.; Hudson, Paul F.; Asquith, William H.

    2015-03-01

    The rural and unregulated Llano River watershed located in central Texas, USA, has a highly variable flow regime and a wide range of instantaneous peak flows. Abrupt transitions in surface lithology exist along the main-stem channel course. Both of these characteristics afford an opportunity to examine hydrologic, lithologic, and sedimentary controls on downstream changes in channel morphology. Field surveys of channel topography and boundary composition are coupled with sediment analyses, hydraulic computations, flood-frequency analyses, and geographic information system mapping to discern controls on channel geometry (profile, pattern, and shape) and dimensions along the mixed alluvial-bedrock Llano River and key tributaries. Four categories of channel classification in a downstream direction include: (i) uppermost ephemeral reaches, (ii) straight or sinuous gravel-bed channels in Cretaceous carbonate sedimentary zones, (iii) straight or sinuous gravel-bed or bedrock channels in Paleozoic sedimentary zones, and (iv) straight, braided, or multithread mixed alluvial-bedrock channels with sandy beds in Precambrian igneous and metamorphic zones. Principal findings include: (i) a nearly linear channel profile attributed to resistant bedrock incision checkpoints; (ii) statistically significant correlations of both alluvial sinuosity and valley confinement to relatively high f (mean depth) hydraulic geometry values; (iii) relatively high b (width) hydraulic geometry values in partly confined settings with sinuous channels upstream from a prominent incision checkpoint; (iv) different functional flow categories including frequently occurring events (excess of 200 watts per square meter (W/m2); and (vi) downstream convergence of hydraulic geometry exponents for bankfull and macrochannels, explained by co-increases of flood magnitude and noncohesive sandy sediments that collectively minimize development of alluvial bankfull indicators. Collectively, these findings indicate

  18. Gravitational signature and apparent mass changes in Amundsen Embayment caused by low viscosity GIA model constrained by rapid bedrock displacement

    Science.gov (United States)

    Barletta, V. R.; Bevis, M.; Smith, B. E.; Wilson, T. J.; Willis, M. J.; Brown, A.; Bordoni, A.; Khan, S. A.; Smalley, R., Jr.; Kendrick, E. C.; Konfal, S. A.; Caccamise, D.; Aster, R.; Chaput, J. A.; Heeszel, D.; Wiens, D.; Lloyd, A. J.

    2015-12-01

    The Amundsen Embayment sector of West Antarctica is experiencing some of the fastest sustained bedrock uplift rates in the world. These motions, recorded by the Antarctic GPS Network (ANET), cannot be explained in terms of the earth's elastic response to contemporary ice loss, and the residues are far too rapid to be explained using traditional GIA models. We use 13 years of very high resolution DEM-derived ice mass change fields over the Amundsen sector to compute the elastic signal and remove it from the observed geodetic time series. We obtain a very large residual - up to 5 times larger than the computed elastic response. Low or very low mantle viscosities are expected in this area based on existing heat flow estimates, seismic velocity anomalies, thin crust, and active volcanism, all of which are associated with geologically recent rifting. We hypothesize that the rapid crustal displacement manifests a low viscosity short-time-scale response to post- Little Ice Age ice mass changes, including ice losses developed in the last decade or so. A plausible ice history for the last hundred years is made by using the actual measurements from 2002 to 2014, and 25% of the present day melting rate before 2002. We then simulate and fit the bedrock displacement - both vertical and horizontal - with a spherical compressible viscoelastic Earth model having a low viscosity shallow upper mantle. We show that we can constrain the shallow upper mantle viscosity very well and also explain most of the signal (amplitude and direction) by using 2 x10^18 Pa s. However we are not able to precisely constrain the thickness of the lithosphere (the preferred thickness is more than 50 km, quite thick for that region) or ice history. By using our preferred set up (earth model + ice history) we compute the GIA gravitational signature and convert it in equivalent superficial water density (see figure) that can be directly used to correct the mass changes observed by GRACE.For the Amundsen

  19. Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qiang [Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9 W, Palisades, NY 10964 (United States); School of Earth and Environmental Sciences, Queens College and Graduate Center, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367 (United States); Culbertson, Charles W.; Nielsen, Martha G.; Schalk, Charles W. [U.S. Geological Survey, Maine Water Science Center, 196 Whitten Road, Augusta, ME 04330 (United States); Johnson, Carole D. [U.S. Geological Survey, Branch of Geophysics, 11 Sherman Place, Unit 5015, University of Connecticut, Storrs, CT 06269 (United States); Marvinney, Robert G. [Maine Geological Survey, 93 State House Station, Augusta, ME 04333 (United States); Stute, Martin [Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9 W, Palisades, NY 10964 (United States); Zheng, Yan, E-mail: yan.zheng@qc.cuny.edu [Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9 W, Palisades, NY 10964 (United States); School of Earth and Environmental Sciences, Queens College and Graduate Center, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367 (United States)

    2015-02-01

    To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70–100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93–99%) in particulates (> 0.45 μm). These particulates and those settled after a 16-day batch experiment contain 560–13,000 mg/kg of As and 14–35% weight/weight of Fe. As/Fe ratios (2.5–20 mmol/mol) and As partitioning ratios (adsorbed/dissolved [As], 20,000–100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ{sup 18}O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes the oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater. - Highlights: • Most Fe and some As exist as particulates in the tested borehole and fracture water.

  20. Bedrock Geologic Map of New Hampshire, a Digital Representation of Lyons and Others 1997 Map and Ancillary Files

    Science.gov (United States)

    Bennett, Derek S.; Lyons, John B.; Wittkop, Chad A.; Dicken, Connie L.

    2006-01-01

    The New Hampshire Geological Survey collects data and performs research on the land, mineral, and water resources of the State, and disseminates the findings of such research to the public through maps, reports, and other publications. The Bedrock Geologic Map of New Hampshire, by John B. Lyons, Wallace A. Bothner, Robert H. Moench, and James B. Thompson, was published in paper format by the U.S. Geological Survey (USGS) in 1997. The online version of this CD contains digital datasets of the State map that are intended to assist the professional geologist, land-use planners, water resource professionals, and engineers and to inform the interested layperson. In addition to the bedrock geology, the datasets include geopolitical and hydrologic information, such as political boundaries, quadrangle boundaries, hydrologic units, and water-well data. A more thorough explanation for each of these datasets may be found in the accompanying metadata files. The data are spatially referenced and may be used in a geographic information system (GIS). ArcExplorer, the Environmental Systems Research Institute's (ESRI) free GIS data viewer, is available at http://www.esri.com/software/arcexplorer. ArcExplorer provides basic functions that are needed to harness the power and versatility of the spatial datasets. Additional information on the viewer and other ESRI products may be found on the ArcExplorer website. Although extensive review and revisions of the data have been performed by the USGS and the New Hampshire Geological Survey, these data represent interpretations made by professional geologists using the best available data, and are intended to provide general geologic information. Use of these data at scales larger than 1:250,000 will not provide greater accuracy. The data are not intended to replace site-specific or specific-use investigations. The U.S. Geological Survey, New Hampshire Geological Survey, and State of New Hampshire make no representation or warranty

  1. Subglacial bedrock topography of an active mountain glacier in a high Alpine setting - insights from high resolution 3D cosmic-muon radiography of the Eiger glacier (Bern, Central Alps, Switzerland)

    Science.gov (United States)

    Mair, David; Lechmann, Alessandro; Nishiyama, Ryuichi; Schlunegger, Fritz; Ariga, Akitaka; Ariga, Tomoko; Scampoli, Paola; Vladymyrov, Mykhailo; Ereditato, Antonio

    2016-04-01

    Bedrock topography and therefore the spatial-altitudinal distribution of ice thickness constrain the ice flow as well as the erosional mechanisms of glaciers. Although the processes by which glaciers have shaped modern and past landscapes have been well investigated, little information is still available about the shape of the bedrock beneath active glaciers in steep Alpine cirques. Here, we we apply the cosmic-muon radiography technology, which uses nuclear emulsion detectors for imaging the bedrock surface. This method should provide information on the bedrock topography beneath a glacier and related ice thicknesses and subglacial meltwater pathways. We apply this technology to the cirque of the Eiger glacier, situated on the western flank of Eiger mountain, Central Swiss Alps. The Eiger glacier originates on the western flank of the Eiger at 3700 m a.s.l., from where it stretches along 2.6 km to the current elevation at 2300 m a.s.l.. The glacier consists of a concave cirque bordered by >40° steep flanks, thereby utilizing weaknesses within the fabric of the bedrock such as folds, joints and foliations. The middle reach hosts a bedrock ridge where glacier diffluence occurs. The lower reaches of the glacier are characterized by several transverse crevasses, while the terminal lobe hosts multiple longitudinal crevasses. A basal till and lateral margins border the ice flow along the lowermost reach. While subglacial erosion in the cirque has probably been accomplished by plucking and abrasion where the glacier might be cold-based, sub glacial melt water might have contributed to bedrock sculpting farther downslope where the ice flow is constrained by bedrock. Overdeepening of some tens of meters is expected in the upper reach of the glacier, which is quite common in cirques (Cook & Swift, 2012). Contrariwise, we expect several tens of meters-deep bedrock excavations (characterized by concave curvatures of bedrock surface) at the site of ice diffluence. The next

  2. Sediment dynamics and the burial and exhumation of bedrock reefs along an emergent coastline as elucidated by repetitive sonar surveys: Northern Monterey Bay, CA

    Science.gov (United States)

    Storlazzi, C.D.; Fregoso, T.A.; Golden, N.E.; Finlayson, D.P.

    2011-01-01

    Two high-resolution bathymetric and acoustic backscatter sonar surveys were conducted along the energetic emergent inner shelf of northern Monterey Bay, CA, USA, in the fall of 2005 and the spring of 2006 to determine the impact of winter storm waves, beach erosion, and river floods on biologically-important siliclastic bedrock reef habitats. The surveys extended from water depths of 4 m to 22 m and covered an area of 3.14 km2, 45.8% of which was bedrock, gravel, and coarse-grained sand and 54.2% was fine-grained sand. Our analyses of the bathymetric and acoustic backscatter data demonstrates that during the 6 months between surveys, 11.4% of the study area was buried by fine-grained sand while erosion resulted in the exposure of bedrock or coarse-grained sand over 26.5% of the study area. The probability of burial decreased with increasing water depth and rugosity; the probability of exhumation increased with increasing wave-induced near-bed shear stress, seabed slope and rugosity. Much of the detected change was at the boundary between bedrock and unconsolidated sediment due to sedimentation and erosion burying or exhuming bedrock, respectively. In a number of cases, however, the change in seabed character was apparently due to changes in sediment grain size when scour exposed what appeared to be an underlying coarser-grained lag or the burial of coarser-grained sand and gravel by fine-grained sand. These findings suggest that, in some places, (a) burial and exhumation of nearshore bedrock reefs along rocky, energetic inner shelves occurs over seasonal timescales and appears related to intrinsic factors such as seabed morphology and extrinsic factors such as wave forces, and (b) single acoustic surveys typically employed for geologic characterization and/or habitat mapping may not adequately characterize the geomorphologic and sedimentologic nature of these types of environments that typify most of the Pacific Ocean and up to 50% of the world's coastlines.

  3. Microbial communities and their predicted metabolic characteristics in deep fracture groundwaters of the crystalline bedrock at Olkiluoto, Finland

    Science.gov (United States)

    Bomberg, Malin; Lamminmäki, Tiina; Itävaara, Merja

    2016-11-01

    The microbial diversity in oligotrophic isolated crystalline Fennoscandian Shield bedrock fracture groundwaters is high, but the core community has not been identified. Here we characterized the bacterial and archaeal communities in 12 water conductive fractures situated at depths between 296 and 798 m by high throughput amplicon sequencing using the Illumina HiSeq platform. Between 1.7 × 104 and 1.2 × 106 bacterial or archaeal sequence reads per sample were obtained. These sequences revealed that up to 95 and 99 % of the bacterial and archaeal sequences obtained from the 12 samples, respectively, belonged to only a few common species, i.e. the core microbiome. However, the remaining rare microbiome contained over 3- and 6-fold more bacterial and archaeal taxa. The metabolic properties of the microbial communities were predicted using PICRUSt. The approximate estimation showed that the metabolic pathways commonly included fermentation, fatty acid oxidation, glycolysis/gluconeogenesis, oxidative phosphorylation, and methanogenesis/anaerobic methane oxidation, but carbon fixation through the Calvin cycle, reductive TCA cycle, and the Wood-Ljungdahl pathway was also predicted. The rare microbiome is an unlimited source of genomic functionality in all ecosystems. It may consist of remnants of microbial communities prevailing in earlier environmental conditions, but could also be induced again if changes in their living conditions occur.

  4. Subsurface mapping of marlstone and limestone facies in the Silurian bedrock of Gotland, by use of Radiomagnetotelluric (RMT) methods

    Science.gov (United States)

    Mikael Erlstroem, Jan; Persson, Lena

    2014-05-01

    The Silurian bedrock on the island of Gotland in the central Baltic Sea is composed of a series of stacked carbonate platforms. Up to 10 cycles of shallow marine back reef, reef and fore reef limestone overlie and interfinger with shallow shelf marl and marlstone deposits. Three main regional, up to 70 m thick limestone dominated bodies with high electrical resistivity are clearly marked in the electromagnetic map. The subsurface structural framework of the different lithofacies is at presently less well known. There is therefore a great interest to develop and test the applicability of different geophysical methods for this purpose. Especially as the limestone bodies constitute important groundwater aquifers and raw material to the lime and steel industry. The primary aim of this investigation is to assess the application of the RMT method regarding obtaining information on the thickness of the limestone body and the subsurface distribution of different lithofacies on central Gotland. RMT is an electromagnetic method that make use of distant radio transmitters in the frequency range between 10-250 kHz. A significant difference in resistivity between the limestone (1 000-10 000 Ωm) and the marlstone (

  5. Vegetation and landscape on crystalline limestone bedrock in the vicinity of Lánov (Giant Mountains, Czech Republic

    Directory of Open Access Journals (Sweden)

    Jitka Málková

    2013-12-01

    Full Text Available This paper evaluates the structure of the landscape and vegetation in an area of 106.4 ha near the quarry by the village Horni Lanov (4 km east of Vrchlabi situated in a low part of the Giant Mountains. The bedrock (crystalline limestone, rugged terrain, soil moisture and management affect the biodiversity at this locality. It is botanically well known and a very valuable region because of the high number of nature conservation-important species and habitats that occur there. A total 517 species of vascular plants were recorded there between 2002 and 2010. The whole area was divided into 36 segments each with a relatively homogeneous vegetation cover consisting of particular species of plants. Classification of the segments was done using a numerical classification (Sorensen’s similarity index and Ellenberg’s indicator values were used to describe the basic environmental features of the individual segments. The species presence/ absence data together with indicator values (light conditions, temperature, water availability, soil reaction and nitrogen activity were evaluated. The PCA ordination of this data set distinguished three basic types of vegetation cover (“forest”, “dry” and “wet” and that the species composition of the vegetation in the area is mostly determined by land-use (deforestation, limestone mining, pasturing and management of forests and soil moisture.

  6. A maximum likelihood estimator for bedrock fracture transmissivities and its application to the analysis and design of borehole hydraulic tests

    Science.gov (United States)

    West, Anthony C. F.; Novakowski, Kent S.; Gazor, Saeed

    2006-06-01

    We propose a new method to estimate the transmissivities of bedrock fractures from transmissivities measured in intervals of fixed length along a borehole. We define the scale of a fracture set by the inverse of the density of the Poisson point process assumed to represent their locations along the borehole wall, and we assume a lognormal distribution for their transmissivities. The parameters of the latter distribution are estimated by maximizing the likelihood of a left-censored subset of the data where the degree of censorship depends on the scale of the considered fracture set. We applied the method to sets of interval transmissivities simulated by summing random fracture transmissivities drawn from a specified population. We found the estimated distributions compared well to the transmissivity distributions of similarly scaled subsets of the most transmissive fractures from among the specified population. Estimation accuracy was most sensitive to the variance in the transmissivities of the fracture population. Using the proposed method, we estimated the transmissivities of fractures at increasing scale from hydraulic test data collected at a fixed scale in Smithville, Ontario, Canada. This is an important advancement since the resultant curves of transmissivity parameters versus fracture set scale would only previously have been obtainable from hydraulic tests conducted with increasing test interval length and with degrading equipment precision. Finally, on the basis of the properties of the proposed method, we propose guidelines for the design of fixed interval length hydraulic testing programs that require minimal prior knowledge of the rock.

  7. Bedrock geologic map of the Hartland and North Hartland quadrangles, Windsor County, Vermont, and Sullivan and Grafton Counties, New Hampshire

    Science.gov (United States)

    Walsh, Gregory J.

    2016-08-16

    The bedrock geology of the 7.5-minute Hartland and North Hartland quadrangles, Vermont-New Hampshire, consists of highly deformed and metamorphosed lower Paleozoic metasedimentary, metavolcanic, and metaplutonic rocks of the Bronson Hill anticlinorium (BHA) and the Connecticut Valley trough (CVT). Rocks of the Orfordville anticlinorium on this map occupy the western part of the broader BHA. In the BHA, the Ordovician Ammonoosuc Volcanics and graphitic, sulfidic metapelite of the Partridge Formation are intruded by Ordovician plutonic rocks of the Oliverian Plutonic Suite. The Ordovician rocks are collectively referred to as the Bronson Hill arc. The Ordovician rocks are overlain by the Silurian to Devonian Clough, Fitch, and Littleton Formations. On this map, rocks of the CVT occupy the eastern part of the broader CVT. In the CVT in Vermont, the Silurian to Devonian Shaw Mountain, Waits River, and Gile Mountain Formations form an unconformable autochthonous to parautochthonous cover sequence on the pre-Silurian rocks of the Rowe-Hawley zone above Precambrian basement rocks of the Mount Holly Complex. On this map, however, only the Waits River and Gile Mountain Formations are exposed. Syn- to postmetamorphic rocks include quartz veins and Cretaceous dikes of the White Mountain Igneous Suite.

  8. MATCHED-INDEX-OF-REFRACTION FLOW FACILITY FOR FUNDAMENTAL AND APPLIED RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Carl Stoots; Donald M. McEligot; Richard Skifton; Hugh McIlroy

    2014-11-01

    Significant challenges face reactor designers with regard to thermal hydraulic design and associated modeling for advanced reactor concepts. Computational thermal hydraulic codes solve only a piece of the core. There is a need for a whole core dynamics system code with local resolution to investigate and understand flow behavior with all the relevant physics and thermo-mechanics. The matched index of refraction (MIR) flow facility at Idaho National Laboratory (INL) has a unique capability to contribute to the development of validated computational fluid dynamics (CFD) codes through the use of state-of-the-art optical measurement techniques, such as Laser Doppler Velocimetry (LDV) and Particle Image Velocimetry (PIV). PIV is a non-intrusive velocity measurement technique that tracks flow by imaging the movement of small tracer particles within a fluid. At the heart of a PIV calculation is the cross correlation algorithm, which is used to estimate the displacement of particles in some small part of the image over the time span between two images. Generally, the displacement is indicated by the location of the largest peak. To quantify these measurements accurately, sophisticated processing algorithms correlate the locations of particles within the image to estimate the velocity (Ref. 1). Prior to use with reactor deign, the CFD codes have to be experimentally validated, which requires rigorous experimental measurements to produce high quality, multi-dimensional flow field data with error quantification methodologies. Computational thermal hydraulic codes solve only a piece of the core. There is a need for a whole core dynamics system code with local resolution to investigate and understand flow behavior with all the relevant physics and thermo-mechanics. Computational techniques with supporting test data may be needed to address the heat transfer from the fuel to the coolant during the transition from turbulent to laminar flow, including the possibility of an early laminarization of the flow (Refs. 2 and 3) (laminarization is caused when the coolant velocity is theoretically in the turbulent regime, but the heat transfer properties are indicative of the coolant velocity being in the laminar regime). Such studies are complicated enough that computational fluid dynamics (CFD) models may not converge to the same conclusion. Thus, experimentally scaled thermal hydraulic data with uncertainties should be developed to support modeling and simulation for verification and validation activities. The fluid/solid index of refraction matching technique allows optical access in and around geometries that would otherwise be impossible while the large test section of the INL system provides better spatial and temporal resolution than comparable facilities. Benchmark data for assessing computational fluid dynamics can be acquired for external flows, internal flows, and coupled internal/external flows for better understanding of physical phenomena of interest. The core objective of this study is to describe MIR and its capabilities, and mention current development areas for uncertainty quantification, mainly the uncertainty surface method and cross-correlation method. Using these methods, it is anticipated to establish a suitable approach to quantify PIV uncertainty for experiments performed in the MIR.

  9. High precision terrestrial laser scanning : measuring the individual impact of floods and landslides on meandering bedrock river dynamics (Rangitikei river, New-Zealand)

    Science.gov (United States)

    Lague, D.; Bonnet, S.; Brodu, N.; Davies, T.; Leroux, J.

    2012-04-01

    Actively incising and meandering bedrock rivers are an ubiquitous feature of mountain belts, but the mechanisms leading to their formation and evolution are still poorly understood. Part of the problem lies in our limited ability to quantify in situ the mechanisms governing the dynamics of straight bedrock rivers (tool-cover effects, stochastic sediment supply and discharge effects, roughness effects,...). But the rapid and spatially variable rates of bank erosion in meanders also lead to potentially more complex hillslope-channel interactions than in straight river. Terrestrial laser scanner has the potential to shed new light on these interactions and to capture over large surfaces the impact of individual flood and landsliding events. Given the small changes of surface position that must be detected for even the largest rates of bedrock erosion (~ 5-10 mm/yr) and the 3D geometrical complexity of bedrock meanders, specific survey approaches and post-processing algorithms must be developed. To this end, we started to perform repeated Terrestrial Laser Scanner (TLS) surveys of actively incising meanders in the Rangitikei river (New-Zealand) in 2009. The Rangitikei river is incising weakly consolidated mudstone at an average rate of 5 mm/yr since 15 kyr and has developed a very sinuous meandering pattern with several cut-off bedrock meanders. Lateral undercutting of 100 m high cliffs generates failures of up to hundred of meters. Alluvial material consists of coarse resistant material (D50 ~20 cm) sourced from upstream, and large boulders locally derived from rockfalls. Exposed bedrock is rare on the bed but shows that abrasion, weathering by wetting-drying cycles and plucking are important incision mechanisms. Six TLS surveys were performed at bi-monthly to yearly intervals with a Leica Scanstation 2 in 5 reaches of variable planform curvature. Survey length varies from 300 m to 1200 m and point spacing from ~ 5 mm to 5 cm. Point clouds were co-registered between

  10. Lithology Identification for the Bedrock of Buried Hill in Lishu Fault Depression%梨树断陷基岩潜山岩性识别

    Institute of Scientific and Technical Information of China (English)

    曹玥; 曹开芳; 李万才

    2014-01-01

    基岩储层测井评价过程中,岩性识别是首先要解决的问题。梨树断陷基岩潜山地层的岩性十分复杂,既有变质岩,也有后期侵入的岩浆岩,又有碳酸盐岩,不同区块岩性分布不同,纵向上岩性变化大。利用录井、岩心分析、测井等多种资料,对岩石矿物成分、测井响应特征等进行分析,获知基岩岩石学特征、建立不同岩性与其测井响应特征关系、建立岩性识别图版,从而实现基岩岩性识别。%The lithology identification is the first important prob-lem in the process of the logging evaluation for the bedrock reservoir. The lithology of the bedrock in Lishu Fault Depression is complex, there are metamorphic rocks,magmatic rocks,and carbonate rocks. The lithology distribution is different in different blocks, the change of the lithology is big on the longitudinal.Using many datas of the logging, core analysis and well logging to analyze the rock mineral composition and the logging response characteristics, learning the petrological characteristics of the bedrock, building the relationships of different lithology and logging response, establishing the lithology identification chart, so as to realize the bedrock lithology identification.

  11. Applying a Model of Curvature-Driven Bend Migration Developed for Alluvial Rivers to a Gravel-Bedded River With Reaches of Exposed Bedrock

    Science.gov (United States)

    Narinesingh, P.; Pizzuto, J. E.

    2009-12-01

    The South River, Virginia, a sinuous, gravel-bedded river influenced by frequent bedrock exposures, appears at first glance to be meandering. However, when its planform statistics are compared to a freely meandering river (the Teklanika River, Alaska), systematic differences become apparent. Bends of the South River have shorter lengths, longer radii of curvatures, a distinctive meander wavelength spectrum, and a lower fractal dimension of D = 1.11 than those of the Teklanika River. Sixty five percent of the length of South River in the study area consists of sections with exposed bedrock (either on the bed or the banks) and islands. Alluvial floodplains of varying lengths are scattered between sections of bedrock and islands, accounting for the remaining 35% of the study reach. In these areas, the South River displays sinuosity values that may be as high as 2.5. Within the alluvial reaches, aerial photographs from 1937 and 2005 document significant channel migration. Driven by the need to quantify the flux of mercury-contaminated sediments entering the river through bank erosion, we applied the bend migration model of Johannesson and Parker (1989). The model, when schematized for hydraulics of the alluvial sections of the South River and calibrated to the total area of erosion mapped from aerial photographs, correctly predicts 45% of the observed locations of erosion as mapped from the aerial photographs and observed in the field. The total area of erosion computed using the predicted near-bank excess velocity is within 14% of that mapped. According to a non-parametric Kruskal-Wallis test, the predicted areas of erosion along the river are not significantly different from those defined by the historical aerial photographs (P >= 0.05, two tailed test). These results suggest that curvature dependent hydraulic models for alluvial rivers may provide useful predictions of total erosion of alluvium on mixed bedrock/alluvial rivers like the South River. However, improved

  12. Case study for delineating a contributing area to a well in a fractured siliciclastic-bedrock aquifer near Lansdale, Pennsylvania

    Science.gov (United States)

    Barton, Gary J.; Risser, Dennis W.; Galeone, Daniel G.; Goode, Daniel J.

    2003-01-01

    A supply well used by the North Penn Water Authority near Lansdale, Pa., was selected as a case study for delineating a contributing area in a fractured siliciclastic-bedrock aquifer. The study emphasized the importance of refining the understanding of factors that control ground-water movement to the well by conducting (1) geophysical logging and flow measurements, (2) ground-water level monitoring, (3) aquifer testing, and (4) geochemical sampling. This approach could be applicable for other wells in siliciclastic-bedrock terranes, especially those of Triassic age in southeastern Pennsylvania. The principal methods for refining the understanding of hydrology at supply well MG-1125 were aquifer testing, water-level measurements, and geophysical logging. Results of two constant-discharge aquifer tests helped estimate the transmissivity of water-producing units and evaluate the anisotropy caused by dipping beds. Results from slug tests provided estimates of transmissivity that were used to evaluate the results from the constant-discharge aquifer tests. Slug tests also showed the wide distribution of transmissivity, indicating that ground-water velocities must vary considerably in the well field. Water-level monitoring in observation wells allowed maps of the potentiometric surface near the well field to be drawn. The measurements also showed that the hydraulic gradient can change abruptly in response to pumping from nearby supply wells. Water levels measured at a broader regional scale in an earlier study also provided a useful view of the potentiometric surface for purposes of delineating the contributing area. Geophysical logging and measurements of flow within wells showed that about 60 percent of water from supply well MG-1125 probably is contributed from relatively shallow water-producing fractures from 60 to 125 feet below land surface, but measurable amounts of water are contributed by fractures to a depth of 311 feet below land surface. Chemical samples

  13. Lead isotope distribution in podzolic soil profiles on different types of bedrock in a formerly glaciated terrain (Oslo, Norway)

    Energy Technology Data Exchange (ETDEWEB)

    Saether, O.M., E-mail: ola.sather@ngu.no [Geological Survey of Norway, Leiv Eirikssons vei 39, NO-7094 Trondheim (Norway); Aberg, G. [Laboratory for Isotope Geology, Box 50007, SE-104 05 Stockholm (Sweden); Steinnes, E. [Department of Chemistry, NTNU, NO-7491 Trondheim (Norway)

    2011-06-15

    Highlights: > Four sites with different lithology (syenite, gneiss, granite, sedimentary rocks), formerly glaciated terrain, Oslo, Norway. > Variations with depth of grain-size, total organic C, Pb concentration, Pb isotope ratio. > Content of anthropogenic Pb in podzolic forest soil. > Comparison of three methods for calculating anthropogenic Pb input. > Amounts of anthropogenic Pb in upper 20 cm calculated to be 1-6 t/km{sup 2}. - Abstract: Lead has been exploited by man over thousands of years for a variety of metallurgical, medicinal, and industrial purposes. The cumulative output of Pb from mining is estimated to be 260 million metric tonnes and 85% of this has occurred over the last two centuries. Global annual production of Pb from mining was about 3 million tonnes at the turn of the millenium. Terrestrial ecosystems all over Norway have been contaminated moderately to strongly by Pb and other trace elements from atmospheric deposition. With the aim of developing a method for mapping the accumulated content of anthropogenic Pb and how deep in the soil profile the atmospherically deposited Pb has penetrated, the concentration of Pb and the {sup 206}Pb/{sup 207}Pb ratio has been studied in podzolic forest soils at four locations with different lithology, i.e. age and type of bedrock, in the Oslo area. The concentrations of Pb in the soil profiles are 6.6-38.1 mg/kg (median 10.3). The {sup 206}Pb/{sup 207}Pb ratio ranges between 1.168 and 1.314 (median 1.267) over the entire profile. In the upper 5 cm the range is 1.168-1.191, similar to ratios determined in recent atmospheric deposition. Applying three different methods, the amount of anthropogenically deposited Pb is estimated at 1-6 t/km{sup 2}.

  14. Delineation of Groundwater Flow Pathway in Fractured Bedrock Using Nano-Iron Tracer Test in the Sealed Well

    Science.gov (United States)

    Chuang, Po-Yu; Chia, Yeeping; Chiu, Yung-Chia; Liou, Ya-Hsuan; Teng, Mao-Hua; Liu, Ching-Yi; Lee, Tsai-Ping

    2016-04-01

    Deterministic delineation of the preferential flow paths and their hydraulic properties are desirable for developing hydrogeological conceptual models in bedrock aquifers. In this study, we proposed using nanoscale zero-valent iron (nZVI) as a tracer to characterize the fractured connectivity and hydraulic properties. Since nZVI particles are magnetic, we designed a magnet array to attract the arriving nZVI particles in the observation well for identifying the location of incoming tracer. This novel approach was examined at two experiment wells with well hydraulic connectivity in a hydrogeological research station in the fractured aquifer. Heat-pulse flowmeter test was used to detect the vertical distribution of permeable zones in the borehole, providing the design basis of tracer test. Then, the less permeable zones in the injection well were sealed by casing to prevent the injected nZVI particles from being stagnated at the bottom hole. Afterwards, hydraulic test was implemented to examine the hydraulic connectivity between two wells. When nZVI slurry was released in the injection well, they could migrate through connected permeable fractures to the observation well. A breakthrough curve was obtained by the fluid conductivity sensor in the observation well, indicating the arrival of nZVI slurry. The iron nanoparticles that were attracted to the magnets in the observation well provide the quantitative information to locate the position of tracer inlet, which corroborates well with the depth of a permeable zone delineated by the flowmeter. Finally, the numerical method was utilized to simulate the process of tracer migration. This article demonstrates that nano-iron tracer test can be a promising approach for characterizing connectivity patterns and transmissivities of the flow paths in the fractured rock.

  15. Bedrock geology and mineral resources of the Knoxville 1° x 2° quadrangle, Tennessee, North Carolina, and South Carolina

    Science.gov (United States)

    Robinson,, Gilpin R.; Lesure, Frank G.; Marlowe, J. I.; Foley, Nora K.; Clark, S.H.

    2004-01-01

    The Knoxville 1°x 2° quadrangle spans the Southern Blue Ridge physiographic province at its widest point from eastern Tennessee across western North Carolina to the northwest corner of South Carolina. The quadrangle also contains small parts of the Valley and Ridge province in Tennessee and the Piedmont province in North and South Carolina. Bedrock in the Valley and Ridge consists of unmetamorphosed, folded and thrust-faulted Paleozoic miogeoclinal sedimentary rocks ranging in age from Cambrian to Mississippian. The Blue Ridge is a complex of stacked thrust sheets divided into three parts: (1) a west flank underlain by rocks of the Late Proterozoic and Early Cambrian Chilhowee Group and slightly metamorphosed Late Proterozoic Ocoee Supergroup west of the Greenbrier fault; (2) a central part containing crystalline basement of Middle Proterozoic age (Grenville), Ocoee Supergroup rocks east of the Greenbrier fault, and rocks of the Murphy belt; and (3) an east flank containing the Helen, Tallulah Falls, and Richard Russell thrust sheets and the amphibolitic basement complex. All of the east flank thrust sheets contain polydeformed and metamorphosed sedimentary and igneous rocks of mostly Proterozoic age. The Blue Ridge is separated by the Brevard fault zone from a large area of rocks of the Inner Piedmont to the east, which contains the Six Mile thrust sheet and the ChaugaWalhalla thrust complex. All of these rocks are also polydeformed and metamorphosed sedimentary and igneous rocks. The Inner Piedmont rocks in this area occupy both the Piedmont and part of the Blue Ridge physiographic provinces.

  16. Carbon transformations by attached bacterial populations in granitic groundwater from deep crystalline bed-rock of the Stripa research mine.

    Science.gov (United States)

    Ekendahl, S; Pedersen, K

    1994-07-01

    This paper presents and compares the assimilation rates of CO2 and lactate, and the lactate respiration rates, of attached bacterial populations growing in slowly flowing groundwater (1-3 mm s-1) from deep crystalline bed-rock of the Stripa research mine, Sweden. The bacteria studied grew in anoxic, high-pH (9-10) and low-redox artesian groundwater flowing up through tubing from two levels of a borehole designated V2, 812-820 m and 970-1240 m below ground. Bacteria were allowed to attach to and grow on sterile glass microscope slides in laminar-flow reactors connected to the flowing groundwater. Total numbers of bacteria were counted by acridine orange direct counts. The bacteria grew slowly, with doubling times of 34 d at 10 degrees C for the 812-820 m population, 23 d for the 970-1240 m population at 10 degrees C and 16 d for this population at 20 degrees C. Numbers of attached bacteria reached between 10(6) and 10(7) bacteria cm-2. The populations at the two levels of the borehole were different in physiology as well as in phylogeny and reflected the heterogeneity between the sampling levels. The earlier proposed presence of sulphate-reducing bacteria could not be confirmed. This is discussed in relation to results from 16S rRNA gene sequencing studies. The CO2 assimilation rates (as mol CO2 cm-2 h-1, using liquid scintillation techniques) increased with depth and temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Investigation of the relationship between ground and engineering bedrock at northern part of the Gulf of İzmir by borehole data supported geophysical works

    Indian Academy of Sciences (India)

    Mustafa Akgün; Tolga Gönenc; Oya Pamukçu; Şenol Özyalin

    2014-04-01

    Loss of life and property that may occur as a result of a possible earthquake can be reduced by earthquake resistant building designs. In order to investigate possible ground motion amplification in earthquake resistant building design, relationship between the ground and engineering bedrock must be ensured. In order to provide this relation, structure, basic characteristics, and thickness of the ground are investigated. In this context, calculating ground transfer function, obtaining horizontal earthquake acceleration changes, calculating values and defining the engineering bedrock are necessary. In this study, Menemen plain, the nothern part of Izmir metropolitan located in active earthquake zone and its immediate vicinity have been examined to define the structure, ground, engineering and bedrock relation. In this context, Menemen plain has been investigated by geophysical methods, which are supported with borehole data (microtremor, MASW – multichannel analysis of surface waves, microgravity measurements, and vertical electrical sounding – VES). Microtremor method was conducted at 377 points in average in the investigation area to define fundamental period and empirical transfer function; after that in order to create basin model and to define the shallow subsurface geometry, microgravity measurements were carried out by using Scintrex CG-5. Also, MASW measurements were carried out in approximately 277 profiles and Schlumberger VES measurements were conducted at approximately 7 points in the investigation area. The existence of a linear relation between H/V peak period values obtained by microtremor measurements and ground thickness in the investigation area is also supported by geothermal drilling logs (depth of 600 m) with microgravity survey. Also, in some parts of the investigation area, it was observed that high velocity () values affected H/V peak period values in sections of the ground close to the surface and there was an inversely correlated

  18. Lithologic and hydrologic controls of mixed alluvial-bedrock channels in flood-prone fluvial systems: bankfull and macrochannels in the Llano River watershed, central Texas, USA

    Science.gov (United States)

    Heitmuller, Frank T.; Hudson, Paul F.; Asquith, William H.

    2015-01-01

    The rural and unregulated Llano River watershed located in central Texas, USA, has a highly variable flow regime and a wide range of instantaneous peak flows. Abrupt transitions in surface lithology exist along the main-stem channel course. Both of these characteristics afford an opportunity to examine hydrologic, lithologic, and sedimentary controls on downstream changes in channel morphology. Field surveys of channel topography and boundary composition are coupled with sediment analyses, hydraulic computations, flood-frequency analyses, and geographic information system mapping to discern controls on channel geometry (profile, pattern, and shape) and dimensions along the mixed alluvial-bedrock Llano River and key tributaries. Four categories of channel classification in a downstream direction include: (i) uppermost ephemeral reaches, (ii) straight or sinuous gravel-bed channels in Cretaceous carbonate sedimentary zones, (iii) straight or sinuous gravel-bed or bedrock channels in Paleozoic sedimentary zones, and (iv) straight, braided, or multithread mixed alluvial–bedrock channels with sandy beds in Precambrian igneous and metamorphic zones. Principal findings include: (i) a nearly linear channel profile attributed to resistant bedrock incision checkpoints; (ii) statistically significant correlations of both alluvial sinuosity and valley confinement to relatively high f (mean depth) hydraulic geometry values; (iii) relatively high b (width) hydraulic geometry values in partly confined settings with sinuous channels upstream from a prominent incision checkpoint; (iv) different functional flow categories including frequently occurring events (values (most ≤ 0.45) that develop at sites with unit stream power values in excess of 200 watts per square meter (W/m2); and (vi) downstream convergence of hydraulic geometry exponents for bankfull and macrochannels, explained by co-increases of flood magnitude and noncohesive sandy sediments that collectively minimize

  19. Geology, Bedrock, Geologic map of the Triassic portion of the Cary 7.5-minute quadrangle., Published in 1999, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Field Observation information as of 1999. It is described as...

  20. Unpublished Digital Bedrock Geologic Map of Cuyahoga National Park and Vicinity, Ohio (NPS, GRD, GRI, CUVA, CUVA digital map) adapted from Ohio Division of Geological Survey maps by Larsen and/or Slucher, and/or others (1996)

    Data.gov (United States)

    National Park Service, Department of the Interior — The Unpublished Digital Bedrock Geologic Map of Cuyahoga National Park and Vicinity, Ohio is composed of GIS data layers complete with ArcMap 9.3 layer (.LYR) files,...

  1. Geology, Bedrock, Geologic Map of the Chapel Hill Quadrangle, Published in 2004, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Field Observation information as of 2004. It is described as...

  2. Geology, Bedrock, Geologic Map of the North Carolina Portion of the Gasburg Quadrangle (Mapping by USGS), Published in 2004, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2004. It is described as...

  3. Geology, Bedrock, Lemon Gap Quad unit polygons. Compiled Polygons., Published in 2006, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2006. It is described as...

  4. Digital bedrock geologic map of the Arlington quadrangle and a Vermont portion of the Shushan quadrangle, Vermont: USGS Open-File Report 95-483, 2 plates, scale 1:24000

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG95-483A Lyttle, PT, Digital bedrock geologic map of the Arlington quadrangle and a Vermont portion of the Shushan quadrangle, Vermont: USGS...

  5. Geology, Bedrock, Tabular data involving the location of design specifics for wells related to the Low-level Radioactive Waste (LLRW) Site Characterization., Published in 1998, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, was produced all or in part from Field Survey/GPS information as of 1998. It is described as 'Tabular data involving the location of...

  6. Geology, Bedrock, Mars Hill Quad unit polygons. Compiled Polygons., Published in 2006, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2006. It is described as...

  7. Geology, Bedrock, Hot Springs Quad unit polygons. Compiled Polygons., Published in 2006, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2006. It is described as...

  8. Geology, Bedrock, Baldwin Gap quad line work. Incomplete lines., Published in 2006, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2006. It is described as...

  9. Questa Baseline and Pre-Mining Ground-Water Quality Investigation. 1. Depth to Bedrock Determinations Using Shallow Seismic Data Acquired in the Straight Creek Drainage Near Red River, New Mexico

    Science.gov (United States)

    Powers, Michael H.; Burton, Bethany L.

    2004-01-01

    In late May and early June of 2002, the U.S. Geological Survey (USGS) acquired four P-wave seismic profiles across the Straight Creek drainage near Red River, New Mexico. The data were acquired to support a larger effort to investigate baseline and pre-mining ground-water quality in the Red River basin (Nordstrom and others, 2002). For ground-water flow modeling, knowledge of the thickness of the valley fill material above the bedrock is required. When curved-ray refraction tomography was used with the seismic first arrival times, the resulting images of interval velocity versus depth clearly show a sharp velocity contrast where the bedrock interface is expected. The images show that the interpreted buried bedrock surface is neither smooth nor sharp, but it is clearly defined across the valley along the seismic line profiles. The bedrock models defined by the seismic refraction images are consistent with the well data.

  10. Geology, Bedrock, Geologic Map of the North Carolina Portion of the Nelson Quadrangle (Mapping by USGS), Published in 2004, 1:24000 (1in=2000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2004. It is described as...

  11. Building deals on bedrock.

    Science.gov (United States)

    Harding, David; Rovit, Sam

    2004-09-01

    The headlines are filled with the sorry tales of companies like Vivendi and AOL Time Warner that tried to use mergers and acquisitions to grow big fast or transform fundamentally weak business models. But, drawing on extensive data and experience, the authors conclude that major deals make sense in only two circumstances: when they reinforce a company's existing basis of competition or when they help a company make the shift, as the industry's competitive base changes. In most stable industries, the authors contend, only one basis--superior cost position, brand power, consumer loyalty, real-asset advantage, or government protection--leads to industry leadership, and companies should do only those deals that bolster a strategy to capitalize on that competitive base. That's what Kellogg did when it acquired Keebler. Rather than bow to price pressures from lesser players, Kellogg sought to strengthen its existing basis of competition--its brand--through Keebler's innovative distribution system. A company coping with a changing industry should embark on a series of acquisitions (most likely coupled with divestitures) aimed at moving the firm to the new competitive basis. That's what Comcast did when changes in government regulations fundamentally altered the broadcast industry. In such cases, speed is essential, the investments required are huge, and half-measures can be worse than nothing at all. Still, the research shows, successful acquirers are not those that try to swallow a single, large, supposedly transformative deal but those that go to the M&A table often and take small bites. Deals can fuel growth--as long as they're anchored in the fundamental way money is made in your industry. Fail to understand that and no amount of integration planning will keep you and your shareholders from bearing the high cost of your mistakes.

  12. Iowa Bedrock Faults

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This fault coverage locates and identifies all currently known/interpreted fault zones in Iowa, that demonstrate offset of geologic units in exposure or subsurface...

  13. Acceptance-criteria for the bedrock for deep geologic disposal of spent nuclear fuel. Proceedings from a seminar at Gothenburg University; Acceptanskriterier foer berggrunden vid djup geologisk slutfoervaring av anvaent kaernbraensle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The seminar was directed to Nordic participants, and discussed disposal in the Nordic crystalline bedrock. Criteria for the bedrock should include: It should give durable mechanical protection for the engineered barriers; give a stable and favorable chemical environment for these barriers; have a low turnover of ground water in the near field; be easy to characterize; give favorable recipient-conditions; not have valuable minerals in workable quantities. These general criteria raise several questions coupled to the safety analysis: e.g. the need for geological, hydrological and geochemical parameters. Which data are missing, which are most difficult to find? What should the site characterization program look like to focus on factors that are of the highest importance according to the safety analysis. The demands on the conditions at a site need to be translated into quantitative criteria, which should be expressed as values that can be measured at the site or deduced from such measurements. These questions were discussed at the seminar, and 21 contributions from Finnish, Norwegian and Swedish participants are reported in these proceedings under the chapters: Coupling to the safety analysis; Methodology and criteria for site selection in a regional geoscientific perspective; Rock as a building material - prognosis and result; Geoscientific criteria for the bedrock at the repository - Mechanical protection; Geoscientific criteria for the bedrock at the repository - Low ground water turnover, chemically favorable and stable environment in the near field; Geoscientific criteria for the bedrock at the repository - Demands on the bedrock concerning the migration of radionuclides.

  14. Recharge to Shale Bedrock at Averill Park, an Upland Hamlet in Eastern New York - An Estimate Based on Pumpage within a Defined Cone of Depression

    Science.gov (United States)

    Randall, Allan D.; Finch, Anne

    2008-01-01

    Water levels beneath parts of Averill Park, a residential hamlet in an upland area of till-mantled shale bedrock in east-central New York, have declined in response to increased withdrawals from new wells. Similar experiences in many upland localities in the northeastern United States have resulted in awareness that the rate of recharge to bedrock can be an important constraint on the density of new development in uplands. Recharge at Averill Park was calculated on the basis of careful estimation of pumpage within a defined cone of depression. The data-collection and recharge-estimation procedures documented herein could be applied in a variety of upland localities in support of community-planning studies. Static water levels measured in 145 wells at Averill Park during the late summer of 2002 defined a 0.54-square-mile cone of depression within which ground-water discharge took place entirely as withdrawals from wells. Rates of withdrawal were estimated largely from surveys in similar neighborhoods a few miles away served by public water supply. Comparison of the water-level measurements in 2002 with measurements on other dates revealed localized declines that could be attributed to new housing developments or commercial demands, but also demonstrated that water levels in 2002 within the cone of depression had stabilized and were not declining persistently over time. Therefore, the current withdrawals were equated to recharge from infiltrating precipitation. Recharge within this area was estimated to average 104 gallons per day per acre, equivalent to 1.4 inches annually, and was sufficient to sustain a residential population of 1.9 persons per acre. This recharge rate is much lower than rates estimated from streamflow records for upland watersheds elsewhere in the northeastern United States. This rate is an average of an unknown larger rate in the 30 percent of the study area where bedrock is discontinuously overlain by less than 30 feet of till and an unknown

  15. Application of Borehole Geophysical Methods for Assessing Agro-Chemical Flow Paths in Fractured Bedrock Underlying the Black Brook Watershed, Northwestern New Brunswick

    Science.gov (United States)

    Desroches, A.; Butler, K.

    2009-05-01

    The upper Saint John River valley represents an economically important agricultural region that suffers from high nitrate levels in the groundwater as a result of fertilizer use. This study focuses on the fractured bedrock aquifer beneath the Black Brook Watershed, near Saint-Andre (Grand Falls), New Brunswick, where prediction of nitrate migration is limited by a lack of knowledge of the bedrock fracture characteristics. Bedrock consists of a fine-grained, siliciclastic unit of the Grog Brook Group gradationally overlain by a carbonate unit assigned to the Matapédia Group. Groundwater flow through the fractured bedrock is expected to be primarily influenced by the distribution and orientation of fractures in these rock units. This study demonstrates the effectiveness of the select suite of borehole-geophysical tools used to identify and describe the fractured bedrock characteristics, and assists in understanding the migration pathways of agrochemical leachate from farm fields. Fracture datasets were acquired from five new vertical boreholes that ranged from 50 to 140 metres in depth, and from three outcrop locations along the new Trans-Canada Highway, approximately two kilometres away. The borehole-geophysical methods used included natural gamma ray (GR), single point resistance (SPR), spontaneous potential (SP), slim-hole optical borehole televiewer (OBI) and acoustic borehole televiewer (ABI). The ABI and OBI tools delivered high-resolution oriented images of the borehole walls, and enabled visualization of fractures in situ, and provided accurate information on the location, orientation, and aperture. The GR, SPR and SP logs identified changes in lithology, bed thickness and conductive fracture zones. Detailed inspection of the borehole televiewer images identified 390 fractures. Equal-area stereographic and rose diagrams of fracture planes have been used to identify three discrete fracture sets: 1) steeply dipping fractures that strike 068o/248o, with

  16. Modeling the mobility of uranium from NORM-rich bedrock using multivariate statistical techniques - The mobility of uranium from U-containing bedrock materials as a function of pH: Implications for tunnel construction

    Energy Technology Data Exchange (ETDEWEB)

    Helmers, Tari; Fjermestad, Halldis; Salbu, Brit; Skipperud, Lindis [Norwegian University of Life Sciences, P.O. Box 5003, 1432 Aas (Norway); Meland, Sondre; Hagelia, Per [Norwegian Public Roads Administration, P.O. Box 8142, 0033 Oslo (Norway)

    2014-07-01

    According to amendments made to the Norwegian Pollution Control Act in 2011, naturally occurring radioactive material is now to be considered as an environmental contaminant, in addition to organic pollutants and trace metals. Environmental contamination is strongly correlated with the mobility and bioavailability of metals and radionuclides in natural systems. In order to determine the risk of environmental contamination from e.g. uranium (U) in alum shale areas, it is of particular importance to determine the mobility of U and trace metals found in the rock materials and their binding mechanisms. By determining the speciation and mobility of uranium and trace metals, better predictions can be made on the transport of contaminants in the environment from intervention like road and tunnel construction. The substrate media analyzed in this work was collected from a future tunnel construction site that is being built in the Gran municipality on National road Rv4 in Norway. The bedrock in the Gran municipality is rich in U-bearing minerals. Therefore, there is high potential for environmental contamination from the rock material removed for tunnel construction purposes. The present work focuses upon the effects of pH and the contact time (substrate media: solution) on the mobility of uranium. In order to identify the effects of pH and contact time on mobility, sample cores collected from an area rich in alum shale were subjected to an extended leaching experiment. In this experiment, the substrate materials were treated with five different pH solutions and were analyzed for different contact times. In addition, the results were compared to data from a sequential extraction experiment. In the leaching experiment, the mobilization of uranium in all of the substrate material was affected by the pH of solution. All of the samples were capable of quickly buffering pH solutions with a pH as low as 4 to neutral-alkaline conditions, attributed to the carbonate minerals

  17. Spatial Based Integrated Assessment of Bedrock and Ground Motions, Fault Offsets, and Their Effects for the October-November 2002 Earthquake Sequence on the Denali Fault, Alaska

    Science.gov (United States)

    Vinson, T. S.; Carlson, R.; Hansen, R.; Hulsey, L.; Ma, J.; White, D.; Barnes, D.; Shur, Y.

    2003-12-01

    A National Science Foundation (NSF) Small Grant Exploratory Research Grant was awarded to the University of Alaska Fairbanks to archive bedrock and ground motions and fault offsets and their effects for the October-November 2002 earthquake sequence on the Denali Fault, Alaska. The scope of work included the accumulation of all strong motion records, satellite imagery, satellite remote sensing data, aerial and ground photographs, and structural response (both measured and anecdotal) that would be useful to achieve the objective. Several interesting data sets were archived including ice cover, lateral movement of stream channels, landslides, avalanches, glacial fracturing, "felt" ground motions, and changes in water quantity and quality. The data sources may be spatially integrated to provide a comprehensive assessment of the bedrock and ground motions and fault offsets for the October-November 2002 earthquake sequence. In the aftermath of the October-November 2002 earthquake sequence on the Denali fault, the Alaskan engineering community expressed a strong interest to understand why their structures and infrastructure were not substantially damaged by the ground motions they experienced during the October-November 2002 Earthquake Sequence on the Denali Fault. The research work proposed under this NSF Grant is a necessary prerequisite to this understanding. Furthermore, the proposed work will facilitate a comparison of Denali events with the Loma Prieta and recent Kocelli and Dozce events in Turkey, all of which were associated with strike-slip faulting. Finally, the spatially integrated data will provide the basis for research work that is truly innovative. For example, is may be possible to predict the observed (1) landsliding and avalanches, (2) changes in water quantity and quality, (3) glacial fracturing, and (4) the widespread liquefaction and lateral spreading, which occurred along the Tok cutoff and Northway airport, with the bedrock and ground motions and

  18. Technology of high density resistivity method for bedrock investigation%高密度电阻率法在基岩勘察中的应用

    Institute of Scientific and Technical Information of China (English)

    邓帅奇; 岳建华; 刘志新; 于业斌

    2012-01-01

    Based on the fundamental theory of tripotential sonde, the paper explained the principle, working method, the process of data processing of high density measurement method of electrical resistivity, and applied it to actual engineering. Through examples of analysis, Wenner array has obvious effect for detecting the up and down situation of bedrock surface due to its high vertical resolution. In addition, Wenner array has advantage of strong signal acquisition and high signal-to-noise ratio. Instead, dipole array has high sensitivity for detecting the internal structure of the bedrock due to its high transverse resolution. While dipole devise also has weak capability on signal acquisition and low ability of anti-jamming. To sum up, the paper concluded that it should get an ideal detecting results by combination. The actual application indicated that this method can get good result of detecting bedrock. It is proved by practice that the application of high density resistivity method in bedrock investigation can get great result. Furthermore: it would do great help to improve the exploration results and accuracy by combining different arrays for comprehensive measurement.%从三电位电极系基本理论出发,对高密度电阻率法常用温纳、偶极及微分装置的分辨率、信号强度等进行了比较研究.实例分析表明,温纳装置测量获得的数据纵向分辨率较高,采集信号的强度大,信噪比高,采用该装置探测基岩面的起伏状况效果明显;偶极装置采集的数据横向分辨率较高,在探测基岩内部构造方面有较好的灵敏度,但该装置采集的信号强度小,抗干扰能力差.在实际应用时,建议运用多种装置形式进行综合测量和对比解释,以进一步提高勘探效果和精度.

  19. Cosmogenic 10Be Chronologies of Moraines and Glacially Scoured Bedrock in the Teton Range, with Implications for Paleoclimatic Events and Tectonic Activity

    Science.gov (United States)

    Licciardi, J. M.; Pierce, K. L.; Thackray, G. D.; Finkel, R. C.; Zimmerman, S. R. H.

    2015-12-01

    At its Pleistocene maximum, the greater Yellowstone glacial system consisted of an ice cap on the Yellowstone Plateau joined by glaciers from adjacent high mountains, including the Teton Range. In prior research, we obtained 112 exposure ages from moraines and bedrock in this region. These chronologies identified asynchronous outlet glacier culminations around the periphery of the Yellowstone glacier complex, supporting a model of spatial and temporal progressions in buildup and decay of the various ice source regions. Here we build on this previous work and present >30 recently developed 10Be exposure ages on glacial features in the Teton Range. Although the Tetons harbored a relatively small portion of the greater Yellowstone ice complex, glaciers in this range left behind some of the region's best-preserved moraine sequences and scoured bedrock. Ongoing investigations are focused on developing moraine chronologies in several drainages on the eastern and western Teton Range fronts, and obtaining exposure ages along scoured bedrock transects in glacial troughs upvalley from the dated moraines to define rates of ice recession. Notably, our dating campaign includes lateral moraines that are offset by the Teton fault, providing a rare opportunity to establish direct constraints on integrated long-term slip rates. All new and previously obtained 10Be ages are calculated using recently published calibrations and scaling of 10Be production rates. Initial results show that massive lateral moraines in selected drainages are several thousands of years older than adjacent distal end moraines, implying that the laterals were constructed during an earlier phase of the last glaciation and then acted to topographically confine subsequent ice advances. Mean ages of ca. 17-16 ka from terminal moraine loops along with limiting ages from scoured bedrock upvalley of the moraines indicate glacier culminations followed by the onset of rapid ice retreat long after the end of the global

  20. Disposal of spent fuel in Olkiluoto bedrock. Programme for research, development and technical design for the pre-construction phase

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    The spent fuel from the nuclear power plants at Olkiluoto and Loviisa will be disposed of in Finnish bedrock. Posiva aims at starting the construction of the disposal facility in the 2010's and the actual disposal operations in 2020. In May 1999 Posiva submitted an application for the so-called Decision-in-Principle (DiP) on the facility to the Finnish Government. According to the application the repository would be based on a KBS-3 type concept and sited at Olkiluoto. The application was approved by the Government in December 2000 and will go next to the Parliament for final approval. However, Posiva has already started the planning for the next programme phase on the assumption that a positive decision will be made. The purpose of the present document is to describe the objectives and major items of research, development, technical planning and design work for the period preceding the construction license. According to the current official guidelines Posiva should prepare for submitting the application for the license in 2010. For the technical development and design work the main target for the starting programme phase is to reach the maturity of design and technical plans that allows the specification of work packages for bid calls and gives sufficient confidence in the technical feasibility of planned operations at the encapsulation facility and in the repository. The main objectives for the complementary characterisation work at Olkiluoto consist of the verification of the present conclusions on site suitability, the definition and identification of suitable rock volumes for repository space and the characterisation of the target host rock for repository design, safety assessment and planning of construction work. The technical design and demonstration work together with the results of complementary site characterisation will provide the basis of the safety case prepared as the support for the construction license application. An integrated safety

  1. Arsenic, iron, lead, manganese, and uranium concentrations in private bedrock wells in southeastern New Hampshire, 2012-2013

    Science.gov (United States)

    Flanagan, Sarah M.; Belaval, Marcel; Ayotte, Joseph D.

    2014-01-01

    nonhealth guidelines—based on aesthetic considerations, such as taste or the staining of laundry and plumbing fixtures—because these contaminants, at the SMCLs, are not considered to present risks to human health. Because lead (Pb) contamination of drinking water typically results from corrosion of plumbing materials belonging to water-system customers but still poses a risk to human health, the EPA established an action level (AL) of 15 μg/L for Pb instead of an MCL or SMCL (U.S. Environmental Protection Agency, 2012). The 15-μg/L AL for Pb has been adopted by the New Hampshire Department of Environmental Services for public water systems, and if exceeded, the public water system must inform their customers and undertake additional actions to control corrosion in the pipes of the distribution system (New Hampshire Department of Environmental Services, 2013). Unlike the quality of drinking water provided by public water suppliers, the quality of drinking water obtained from private wells in New Hampshire is not regulated; consequently, private wells are sampled only when individual well owners voluntarily choose to sample them. The U.S. Geological Survey (USGS), in cooperation with the EPA New England, conducted an assessment in 2012–13 to provide private well owners and State and Federal health officials with information on the distribution of trace-metal (As, Fe, Pb, Mn, and U) concentrations in groundwater from bedrock aquifers in the three counties of southeastern New Hampshire. This fact sheet analyzes data from water samples collected by a randomly selected group of private well owners from the three-county study area and describes the major findings for trace-metal concentrations.

  2. Cerium sequestration and accumulation in fractured crystalline bedrock: The role of Mn-Fe (hydr-)oxides and clay minerals

    Science.gov (United States)

    Yu, Changxun; Drake, Henrik; Mathurin, Frédéric A.; Åström, Mats E.

    2017-02-01

    This study focuses on the mechanisms of Ce sequestration and accumulation in the fracture network of the upper kilometer of the granitoid bedrock of the Baltic Shield in southeast Sweden (Laxemar area, Sweden). The material includes 81 specimens of bulk secondary mineral precipitates (;fracture coatings;) collected on fracture walls identified in 17 drill cores, and 66 groundwater samples collected from 21 deep boreholes with equipment designed for retrieval of representative groundwater at controlled depths. The concentrations of Ce in the fracture coatings, although varying considerably (10-90th percentiles: 67-438 mg kg-1), were frequently higher than those of the wall rock (10-90th percentiles: 70-118 mg kg-1). Linear combination fitting analysis of Ce LIII-edge X-ray absorption near-edge structure (XANES) spectra, obtained for 19 fracture coatings with relatively high Ce concentrations (⩾145 mg kg-1) and a wide range of Ce-anomaly values, revealed that Ce(IV) occurs frequently in the upper 10 m of the fracture network (Ce(IV)/Cetotal = 0.06-1.00 in 8 out of 11 specimens) and is mainly associated with Mn oxides (modeled as Ce oxidatively scavenged by birnessite). These features are in line with the strong oxidative and sorptive capacities of Mn oxide as demonstrated by previous studies, and abundant todorokite and birnessite-like Mn oxides identified in 3 out of 4 specimens analyzed by Mn K-edge X-ray absorption spectroscopy (XAS) in the upper parts of the fracture network (down to 5 m). For a specimen with very high Ce concentration (1430 mg kg-1) and NASC-normalized Ce anomaly (3.63), the analysis of Ce XANES and Mn XAS data revealed (i) a predominance of Ce oxide in addition to Ce scavenged by Mn oxide; and (ii) a large fraction of poorly-crystalline hexagonal birnessite and aqueous Mn2+, suggesting a recent or on-going oxidation of Mn2+ in this fracture. In addition, the Ce oxide precipitates on this fracture observed by in situ SEM-EDS contained

  3. Use of Bedrock and Geomorphic Mapping Compilations in Assessing Geologic Hazards at Recreation Sites on National Forests in NW California

    Science.gov (United States)

    de La Fuente, J. A.; Bell, A.; Elder, D.; Mowery, R.; Mikulovsky, R.; Klingel, H.; Stevens, M.

    2010-12-01

    Geologic hazards on US Forest Service lands have a long history of producing catastrophic events. In 1890 (prior to the establishment of the Forest Service), the China Mine landslide buried a miner’s camp along the Trinity River in NW California, killing a number of miners. An earthquake in southwestern Montana triggered a massive landslide which killed 28 people in a US Forest Service campground in 1959. In 1980, Mount St. Helens erupted in Oregon, killing 57 people. Debris flows from a winter storm in 2003 on the burned hillslopes of the San Bernardino National Forest in California killed 14 people at the St. Sophia youth Camp. A rockfall in the summer of 2009 in Lassen National Park killed a 9 year old boy. The most recent catastrophe occurred on June 11, 2010 when 20 people died in a flash flood at the Albert Pike Campground on the Ouachita National Forest. These and other disasters point out the need for geologic hazard mapping and assessments on the National Forests. The US Forest Service (USFS) is currently assessing geologic hazards in the Northern Province of USFS Region 5 (Pacific Southwest Region), which includes the Klamath, Mendocino, Shasta-Trinity, and Six Rivers National Forests. The most common geologic hazards (relatively short return intervals) in this area include landslides, rock falls, debris flows, flooding, temporary dam failures (landslide or woody debris), naturally occurring hazardous materials, (asbestos radon, etc), and rarely, karst subsidence. Seismic and volcanic hazards are also important at longer return intervals. This assessment will be conducted in three phases, and is patterned after a process developed by Region 8 of the US Forest Service. The first phase is a reconnaissance level assessment based on existing information such as spatial databases, aerial photos, Digital Elevation Models, State of California Alquist-Priolo Earthquake Fault Zone maps, previous investigations and anecdotal accounts of past events. The bedrock

  4. Final disposal of spent fuel in the Finnish bedrock. Detailed site investigations 1993-1996; Kaeytetyn polttoaineen loppusijoitus Suomen kallioperaeaen. Yksityiskohtaiset sijoituspaikkatutkimukset 1993-1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    Posiva Oy, jointly owned company of Imatran Voima Oy (IVO) and Teollisuuden Voima Oy (TVO), studies the Finnish bedrock for the final disposal of the spent nuclear fuel. The study is in accordance with the decision in principle by Finnish government in 1983 and aims at site selection. The report is the summary of the first stage of the detailed site investigations carried out during the years 1993-1996. The three sites in question, Romuvaara in Kuhmo, Kivetty in Aeaenekoski and Olkiluoto in Eurajoki were selected for the detailed characterization on the basis of the preliminary site investigations at five areas. The interim reporting in 1996 is comprehensive and comprises a series of reports covering different disciplines and sites. The programme for 1993-1996 was divided into three sub-programs: (1) the baseline investigations describing the present conditions in the bedrock, (2) the additional characterization for the acquisition of complementary data, and (3) the investigations for testing the earlier results and hypotheses to build confidence in existing understanding. (refs.).

  5. Difference of brightness temperatures between 19.35 GHz and 37.0 GHz in CHANG'E-1 MRM: implications for the burial of shallow bedrock at lunar low latitude

    Institute of Scientific and Technical Information of China (English)

    Wen YU; Xiongyao LI; Guangfei WEI; Shijie WANG

    2016-01-01

    Indications of buried lunar bedrock may help us to understand the tectonic evolution of the Moon and provide some clues for formation of lunar regolith.So far,the information on distribution and burial depth of lunar bedrock is far from sufficient.Due to good penetration ability,microwave radiation can be a potential tool to ameliorate this problem.Here,a novel method to estimate the burial depth of lunar bedrock is presented using microwave data from Chang'E-1 (CE-1) lunar satellite.The method is based on the spatial variation of differences in brightness temperatures between 19.35 GHz and 37.0 GHz (△TB).Large differences are found in some regions,such as the southwest edge of Oceanus Procellarum,the area between Mare Tranquillitatis and Mare Nectaris,and the highland east of Mare Smythii.Interestingly,a large change of elevation is found in the corresponding region,which might imply a shallow burial depth of lunar bedrock.To verify this deduction,a theoretical model is derived to calculate the △TB.Results show that △TB varies from 12.7 K to 15 K when the burial depth of bedrock changes from 1 m to 0.5 m in the equatorial region.Based on the available data at low lunar latitude (30°N-30°S),it is thus inferred that the southwest edge of Oceanus Procellarum,the area between Mare Tranquillitatis and Mare Nectaris,the highland located east of Mare Smythii,the edge of Pasteur and Chaplygin are the areas with shallow bedrock,the burial depth is estimated between 0.5 m and 1 m.

  6. Difference of brightness temperatures between 19.35 GHz and 37.0 GHz in CHANG'E-1 MRM: implications for the burial of shallow bedrock at lunar low latitude

    Science.gov (United States)

    Yu, Wen; Li, Xiongyao; Wei, Guangfei; Wang, Shijie

    2016-03-01

    Indications of buried lunar bedrock may help us to understand the tectonic evolution of the Moon and provide some clues for formation of lunar regolith. So far, the information on distribution and burial depth of lunar bedrock is far from sufficient. Due to good penetration ability, microwave radiation can be a potential tool to ameliorate this problem. Here, a novel method to estimate the burial depth of lunar bedrock is presented using microwave data from Chang'E-1 (CE-1) lunar satellite. The method is based on the spatial variation of differences in brightness temperatures between 19.35 GHz and 37.0 GHz (ΔTB). Large differences are found in some regions, such as the southwest edge of Oceanus Procellarum, the area between Mare Tranquillitatis and Mare Nectaris, and the highland east of Mare Smythii. Interestingly, a large change of elevation is found in the corresponding region, which might imply a shallow burial depth of lunar bedrock. To verify this deduction, a theoretical model is derived to calculate the ΔTB. Results show that ΔTB varies from 12.7 K to 15 K when the burial depth of bedrock changes from 1 m to 0.5 m in the equatorial region. Based on the available data at low lunar latitude (30°N-30°S), it is thus inferred that the southwest edge of Oceanus Procellarum, the area between Mare Tranquillitatis and Mare Nectaris, the highland located east of Mare Smythii, the edge of Pasteur and Chaplygin are the areas with shallow bedrock, the burial depth is estimated between 0.5 m and 1 m.

  7. Accuracy of CFC groundwater dating in a crystalline bedrock aquifer: Data from a site in southern Sweden

    Science.gov (United States)

    Bockgård, Niclas; Rodhe, Allan; Olsson, K. A.

    The concentrations of chlorofluorocarbons (CFC-11, CFC-12, and CFC-113) and tritium were determined in groundwater in fractured crystalline bedrock at Finnsjön, Sweden. The specific goal was to investigate the accuracy of CFC dating in such an environment, taking potential degradation and mixing of water into consideration. The water was sampled to a depth of 42 m in three boreholes along an 800-m transect, from a recharge area to a local discharge area. The CFC-113 concentration was at the detection limit in most samples. The apparent recharge date obtained from CFC-11 was earlier than from CFC-12 for all samples, with a difference of over 20 years for some samples. The difference was probably caused by degradation of CFC-11. The CFC-12 dating of the samples ranged from before 1945 to 1975, with the exception of a sample from the water table, which had a present-day concentration. Conclusions about flow paths or groundwater velocity could not be drawn from the CFCs. The comparison between CFC-12 and tritium concentrations showed that most samples could be unmixed or mixtures of waters with different ages, and the binary mixtures that matched the measured concentrations were determined. The mixing model approach can be extended with additional tracers. Précision de la datation au CFC dans un aquifère rocheux-fracturé: données d'un site du sud de la Suède. Les concentrations en chlorofluorocarbones (CFC-11, CFC-12, CFC-113) et entritium ont été déterminées dans l'eau souterraine d'un massif fracturé à Finnsjön en Suède. Le but de cette étude est de mieux cerner la précision de la méthode de datation au CFC dans ce type d'environnement hydrogéologique, tout en considérant d'éventuels phénomènes de dégradation et de mélange d'eaux. L'eau a été échantillonnée à une profondeur de 42 mètres dans trois forages alignés sur 800 mètres entre une zone de recharge et une zone de déversement. Les concentrations en CFC-113 sont dans la plupart

  8. Characterizing Hydraulic Properties and Ground-Water Chemistry in Fractured-Rock Aquifers: A User's Manual for the Multifunction Bedrock-Aquifer Transportable Testing Tool (BAT3)

    Science.gov (United States)

    Shapiro, Allen M.

    2007-01-01

    A borehole testing apparatus has been designed to isolate discrete intervals of a bedrock borehole and conduct hydraulic tests or collect water samples for geochemical analyses. This borehole testing apparatus, referred to as the Multifunction Bedrock-Aquifer Transportable Testing Tool (BAT3), includes two borehole packers, which when inflated can form a pressure-tight seal against smooth borehole walls; a pump apparatus to withdraw water from between the two packers; a fluid-injection apparatus to inject water between the two packers; pressure transducers to monitor fluid pressure between the two packers, as well as above and below the packers; flowmeters to monitor rates of fluid withdrawal or fluid injection; and data-acquisition equipment to record and store digital records from the pressure transducers and flowmeters. The generic design of this apparatus was originally discussed in United States Patent Number 6,761,062 (Shapiro, 2004). The prototype of the apparatus discussed in this report is designed for boreholes that are approximately 6 inches in diameter and can be used to depths of approximately 300 feet below land surface. The apparatus is designed to fit in five hard plastic boxes that can be shipped by overnight freight car-riers. The equipment can be assembled rapidly once it is removed from the shipping boxes, and the length of the test interval (the distance between the two packers) can be adjusted to account for different borehole conditions without reconfiguring the downhole components. The downhole components of the Multifunction BAT3 can be lowered in a borehole using steel pipe or a cable; a truck mounted winch or a winch and tripod can be used for this purpose. The equipment used to raise and lower the downhole components of the Multifunction BAT3 must be supplied on site, along with electrical power, a compressor or cylinders of compressed gas to inflate the packers and operate downhole valves, and the proper length of tubing to connect the

  9. Results of the reactant sand-fracking pilot test and implications for the in situ remediation of chlorinated VOCs and metals in deep and fractured bedrock aquifers.

    Science.gov (United States)

    Marcus, D L; Bonds, C

    1999-08-12

    Permeable reactive barriers (PRBs), such as the Waterloo Funnel and Gate System, first implemented at Canadian Forces Borden facility in 1992, are a passive remediation technology capable of controlling the migration of, and treating contaminated groundwater in situ. Most of the PRBs installed to date have been shallow installations created by backfilling sheet-pile shored excavations with iron filing reactive media. More recently continuous trenchers [R. Puls, Installation of permeable reactive barriers using continuous trenching equipment, Proceedings of the RTDF Permeable Barriers Work Group, Virginia Beach, VA, September 1997] and Caissons [J. Vogan, Caisson installation of a pilot scale, permeable reactive barrier in situ treatment zone at the Sommersworth Landfill, NH, Presented to the RTDF Permeable Barriers Work Group, Alexandria, VA, April 1996], and vertical fracturing emplacements [G. Hocking, Vertical hydraulic fracture emplacement of permeable reactive barriers, Progress Report delivered to the Permeable Reactive Barriers Workgroup of the Remedial Technology Development Forum, Beaverton, OR, April 1998] have been used to create reactive barriers in soil. None of the prior methods are capable of adequately addressing groundwater contamination in deep and fractured bedrock aquifers. The purpose of the RSF pilot study was to install reactive media into an impacted bedrock aquifer, and to evaluate the effectiveness of in situ treatment of chlorinated volatile organic compounds (CVOCs) and metals in that type of aquifer. Three discrete fractures were identified and treated and were subjected to testing before and after treatment. Between 300 and 1700 lb. of 1 mm diameter reactive proppants were injected into each zone to facilitate treatment. Monitoring data obtained from adjacent observation wells verified that fracking fluids reached at least 42 ft from the treatment well following hydrofracturing. The concentrations of many of the CVOCs decreased up to

  10. Comparison of the bedrock depth from array measurements of Rayleigh waves associated with microtremor and seismic profile obtained the Seismic Reflection Data, Eskisehir Basin, Turkey

    Science.gov (United States)

    Tün, Muammer; Karabulut, Savaş; Özel, Oğuz

    2015-04-01

    Ground motion estimation for future earthquakes is one of the most challenging problems in seismology and earthquake engineering. The bedrock depth has a considerable seismic risk for the urban area of Eskişehir. In this study, multiple station microtremor measurement methods which are more practical, non-distructive, fast and economical compared to seismic reflection method were implemented. These method using microtremor recordings have become a very useful data for microzonation studies because of their simple acquisition and analysis. Extensive ambient noise measurements were performed in the basin of Eskisehir from June 2010 to spring 2012. We use data recorded by a broadband seismometer and digitizer CMG-6TD, Guralp seismometer. Some of the measurement locations, the CMG-6TD sensor was located into 30 cm-deep holes in the ground to avoid strongly wind-generated, long-period noise. Dominant frequency (f), bed-rock depth (h) and shear-wave velocity (Vs) were determined from Spatial Autocorrelation (SPAC) methods. With the SPAC Method, it is possible to constrain the velocity structure underlying the site using microtremor array measurements. The results obtained were compared to the 96-channel seismic reflection data with explosive energy source. Several seismic reflection surveys with P-Gun seismic source have been performed on the same place with array measurements. We used two types of seismic sources: 36 cartridge Gun. Shot interval was 10 meters, group interval (one geophone per group, 48 geophones in total) was 10 meters, near offset was 10 meters, far offset was 480 meters, CDP interval was 5 meters. We adapted the 'Off-End Spread' technique while using the Gun. Reflection images within the sedimentary section correlate well with the velocity structure obtained from SPAC.

  11. Preliminary bedrock and surficial geologic map of the west half of the Sanders 30' x 60' quadrangle, Navajo and Apache Counties, northern Arizona

    Science.gov (United States)

    Amoroso, Lee; Priest, Susan S.; Hiza-Redsteer, Margaret

    2014-01-01

    The bedrock and surficial geologic map of the west half of the Sanders 30' x 60' quadrangle was completed in a cooperative effort of the U.S. Geological Survey (USGS) and the Navajo Nation to provide regional geologic information for management and planning officials. This report provides baseline geologic information that will be useful in future studies of groundwater and surface water resources, geologic hazards, and the distribution of soils and plants. The west half of the Sanders quadrangle encompasses approximately 2,509 km2 (980 mi2) within Navajo and Apache Counties of northern Arizona and is bounded by lat 35°30' to 35° N., long 109°30' to 110° W. The majority of the land within the map area lies within the Navajo Nation. South of the Navajo Nation, private and State lands form a checkerboard pattern east and west of Petrified Forest National Park. In the west half of the Sanders quadrangle, Mesozoic bedrock is nearly flat lying except near folds. A shallow Cenozoic erosional basin that developed about 20 Ma in the western part of the map area cut across late Paleozoic and Mesozoic rocks that were subsequently filled with flat-lying Miocene and Pliocene mudstone and argillaceous sandstone and fluvial sediments of the Bidahochi Formation and associated volcanic rocks of the Hopi Buttes volcanic field. The Bidahochi rocks are capped by Pliocene(?) and Pleistocene fluvial sediments and Quaternary eolian and alluvial deposits. Erosion along northeast-southwest-oriented drainages have exposed elongated ridges of Bidahochi Formation and basin-fill deposits that are exposed through shallow eolian cover of similarly oriented longitudinal dunes. Stokes (1964) concluded that the accumulation of longitudinal sand bodies and the development of confined parallel drainages are simultaneous processes resulting in parallel sets of drainages and ridges oriented along the prevailing southwest wind direction on the southern Colorado Plateau.

  12. Fluctuations in groundwater levels related to regional and local withdrawals in the fractured-bedrock groundwater system in northern Wake County, North Carolina, March 2008-February 2009

    Science.gov (United States)

    Chapman, Melinda J.; Almanaseer, Naser; McClenney, Bryce; Hinton, Natalie

    2011-01-01

    A study of dewatering of the fractured-bedrock aquifer in a localized area of east-central North Carolina was conducted from March 2008 through February 2009 to gain an understanding of why some privately owned wells and monitoring wells were intermittently dry. Although the study itself was localized in nature, the resulting water-resources data and information produced from the study will help enable resource managers to make sound water-supply and water-use decisions in similar crystalline-rock aquifer setting in parts of the Piedmont and Blue Ridge Physiographic Provinces. In June 2005, homeowners in a subdivision of approximately 11 homes on lots approximately 1 to 2 acres in size in an unincorporated area of Wake County, North Carolina, reported extremely low water pressure and temporarily dry wells during a brief period. This area of the State, which is in the Piedmont Physiographic Province, is undergoing rapid growth and development. Similar well conditions were reported again in July 2007. In an effort to evaluate aquifer conditions in the area of intermittent water loss, a study was begun in March 2008 to measure and monitor water levels and groundwater use. During the study period from March 2008 through February 2009, regular dewatering of the fractured-bedrock aquifer was documented with water levels in many wells ranging between 100 and 200 feet below land surface. Prior to this period, water levels from the 1980s through the late 1990s were reported to range from 15 to 50 feet below land surface. The study area includes three community wells and more than 30 private wells within a 2,000-foot radius of the dewatered private wells. Although groundwater levels were low, recovery was observed during periods of heavy rainfall, most likely a result of decreased withdrawals owing to less demand for irrigation purposes. Similar areal patterns of low groundwater levels were delineated during nine water-level measurement periods from March 2008 through

  13. Case study for delineating a contributing area to a water-supply well in a fractured crystalline-bedrock aquifer, Stewartstown, Pennsylvania

    Science.gov (United States)

    Barton, Gary J.; Risser, Dennis W.; Galeone, Daniel G.; Conger, Randall W.

    1999-01-01

    The Trouts Lane well field in Stewartstown, Pa., was selected as a case study for delineating a contributing area in a fractured crystalline-bedrock aquifer. The study emphasized the importance of refining the understanding of boundary conditions and major heterogeneities that affect ground-water movement to the supply well by conducting (1) fracture-trace mapping, (2) borehole logging and flow measurements, (3) ground-water level monitoring, (4) aquifer testing, and (5) geochemical sampling. Methods and approach used in this study could be applicable for other wells in crystalline-bedrock terranes in southeastern Pennsylvania. Methods of primary importance for refining the understanding of hydrology at the Trouts Lane well field were the aquifer tests, water-level measurements, and geophysical logging. Results from the constant-discharge aquifer test helped identify a major north-south trending hydraulic connection between supply well SW6 and a domestic-supply well. Aquifer-test results also indicated fractures that transmit most water to the supply well are hydraulically well-connected to the shallow regolith and highly weathered schist. Results from slug tests provided estimates of transmissivity and the nonuniform distribution of transmissivity throughout the well field, indicating the water-producing fractures are not evenly distributed and ground-water velocities must vary considerably throughout the well field.Water levels, which were easy to measure, provided additional evidence of hydraulic connections among wells. More importantly, they allowed the water-table configuration to be mapped. Borehole geophysics and flow measurements within the well were very useful because results indicated water entered supply well SW6 through bedrock fractures at very shallow depths?less than 60 ft below land surface; therefore, the area providing recharge to the well is probably in the immediate vicinity. Preliminary delineations of the contributing area and the 90-day

  14. Comparison of the behaviour of rare earth elements in surface waters, overburden groundwaters and bedrock groundwaters in two granitoidic settings, Eastern Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Roennback, Pernilla [School of Pure and Applied Natural Sciences, University of Kalmar, SE-391 82 Kalmar (Sweden)], E-mail: pernilla.ronnback@hik.se; Astroem, Mats [School of Pure and Applied Natural Sciences, University of Kalmar, SE-391 82 Kalmar (Sweden); Gustafsson, Jon-Petter [Department of Land and Water Resources Engineering, KTH, Royal Institute of Technology, SE-100 44 Stockholm (Sweden)

    2008-07-15

    This work, which was done within the Swedish nuclear waste management program, was carried out in order to increase the understanding of the mobility and fate of rare earth elements (REEs) in natural boreal waters in granitoidic terrain. Two areas were studied, Forsmark and Simpevarp, one of which will be selected as a site for spent nuclear fuel. The highest REE concentrations were found in the overburden groundwaters, in Simpevarp in particular (median {sigma}REE 52 {mu}g/L), but also in Forsmark (median {sigma}REE 6.7 {mu}g/L). The fractionation patterns in these waters were characterised by light REE (LREE) enrichment and negative Ce and Eu anomalies. In contrast, the surface waters had relatively low REE concentrations. They were characterised either by an increase in relative concentrations throughout the lanthanide series (Forsmark which has a carbonate-rich till) or flat patterns (Simpevarp with carbonate-poor till), and had negative Ce and Eu anomalies. In the bedrock groundwaters, the concentrations and fractionation patterns of REEs were entirely different from those in the overburden groundwaters. The median La concentrations were low (just above 0.1 {mu}g/L in both areas), only in a few samples were the concentrations of several REEs (and in a couple of rare cases all REEs) above the detection limit, and there was an increase in the relative concentrations throughout the lanthanide series. In contrast to these large spatial variations, the temporal trends were characterised by small (or non existent) variations in REE-fractionation patterns but rather large variations in concentrations. The Visual MINTEQ speciation calculations predicted that all REEs in all waters were closely associated with dissolved organic matter, and not with carbonate. In the hydrochemical data for the overburden groundwater in particular, there was however a strong indication of association with inorganic colloids, which were not included in the speciation model. Overall the

  15. Multi-isotope (carbon and chlorine) analysis for fingerprinting and site characterization at a fractured bedrock aquifer contaminated by chlorinated ethenes

    Energy Technology Data Exchange (ETDEWEB)

    Palau, Jordi, E-mail: jordi.palau@unine.ch [Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona (Spain); Marchesi, Massimo [Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona (Spain); Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Chambon, Julie C.C. [Department of Environmental Engineering, Technical University of Denmark, 2800 Lyngby (Denmark); Aravena, Ramon [Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Canals, Àngels [Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona (Spain); Binning, Philip J.; Bjerg, Poul L. [Department of Environmental Engineering, Technical University of Denmark, 2800 Lyngby (Denmark); Otero, Neus; Soler, Albert [Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona (Spain)

    2014-03-01

    The use of compound specific multi-isotope approach (C and Cl) in the characterization of a chlorinated ethenes contaminated fractured aquifer allows the identification of several sources and contaminant plumes, as well as the occurrence of biodegradation and mixing processes. The study site is located in Spain with contamination resulting in groundwater concentrations of up to 50 mg/L of trichloroethene (TCE), the most abundant chlorinated ethene, and 7 mg/L of tetrachloroethene (PCE). The potential sources of contamination including abandoned barrels, an underground tank, and a disposal lagoon, showed a wide range in δ{sup 13}C values from − 15.6 to − 40.5‰ for TCE and from − 18.5 to − 32.4‰ for PCE, allowing the use of isotope fingerprinting for tracing of the origin and migration of these contaminants in the aquifer. In contrast, there is no difference between the δ{sup 37}Cl values for TCE in the contaminant sources, ranging from + 0.53 to + 0.66‰. Variations of δ{sup 37}Cl and δ{sup 13}C in the different contaminant plumes were used to investigate the role of biodegradation in groundwater. Moreover, the isotopic data were incorporated into a reactive transport model for determination of whether the isotope pattern observed downstream from the tank's source could be explained by the simultaneous effect of mixing and biodegradation. The results demonstrate that a multi-isotope approach is a valuable tool for characterization of complex sites such as fractured bedrock aquifer contaminated by multiple sources, providing important information which can be used by consultants and site managers to prioritize and design more successful remediation strategies. - Highlights: • Origin and fate of CAHs in groundwater by means of multi CSIA ({sup 13}C,{sup 35}Cl) survey • Innovative/new approach tested in a fractured bedrock site • Differentiation of distinct CAH sources • Biodegradation and source mixing recognition in the aquifer.

  16. Environmental impacts of oil production on soil, bedrock, and vegetation at the U.S. Geological Survey Osage-Skiatook Petroleum Environmental Research site A, Osage County, Oklahoma

    Science.gov (United States)

    Otton, J.K.; Zielinski, R.A.; Smith, B.D.; Abbott, M.M.; Keeland, B.D.

    2005-01-01

    The U.S. Geological Survey is investigating the impacts of oil and gas production on soils, groundwater, surface water, and ecosystems in the United States. Two sites in northeastern Oklahoma (sites A and B) are presently being investigated under the Osage-Skiatook Petroleum Environmental Research project. Oil wells on the lease surrounding site A in Osage County, Oklahoma, produced about 100,000 bbl of oil between 1913 ard 1981. Prominent production features on the 1.5-ha (3.7-ac) site A include a tank battery, an oil-filled trench, pipelines, storage pits for both produced water and oil, and an old power unit. Site activities and historic releases have left open areas in the local oak forest adjacent to these features and a deeply eroded salt scar downslope from the pits that extends to nearby Skiatook Lake. The site is underlain by surficial sediments comprised of very fine-grained eolian sand and colluvium as much as 1.4 m (4.6 ft) thick, which, in turn, overlie flat-lying, fractured bedrock comprised of sandstone, clayey sandstone, mudstone, and shale. A geophysical survey of ground conductance and concentration measurements of aqueous extracts (1:1 by weight) of core samples taken in the salt scar and adjacent areas indicate that unusual concentrations of NaCl-rich salt are present at depths to at least 8 m (26 ft) in the bedrock; however, little salt occurs in the eolian sand. Historic aerial photographs, anecdotal reports from oil-lease operators, and tree-ring records indicate that the surrounding oak forest was largely established after 1935 and thus postdates the majority of surface damage at the site. Blackjack oaks adjacent to the salt scar have anomalously elevated chloride (>400 ppm) in their leaves and record the presence of NaCl-rich salt or salty water in the shallow subsurface. The geophysical measurements also indicate moderately elevated conductance beneath the oak forest adjoining the salt scar. Copyright ?? 2005. The American Association of

  17. Enzyme leaching of surficial geochemical samples for detecting hydromorphic trace-element anomalies associated with precious-metal mineralized bedrock buried beneath glacial overburden in northern Minnesota

    Science.gov (United States)

    Clark, Robert J.; Meier, A.L.; Riddle, G.; ,

    1990-01-01

    One objective of the International Falls and Roseau, Minnesota, CUSMAP projects was to develop a means of conducting regional-scale geochemical surveys in areas where bedrock is buried beneath complex glacially derived overburden. Partial analysis of B-horizon soils offered hope for detecting subtle hydromorphic trace-element dispersion patterns. An enzyme-based partial leach selectively removes metals from oxide coatings on the surfaces of soil materials without attacking their matrix. Most trace-element concentrations in the resulting solutions are in the part-per-trillion to low part-per-billion range, necessitating determinations by inductively coupled plasma/mass spectrometry. The resulting data show greater contrasts for many trace elements than with other techniques tested. Spatially, many trace metal anomalies are locally discontinuous, but anomalous trends within larger areas are apparent. In many instances, the source for an anomaly seems to be either basal till or bedrock. Ground water flow is probably the most important mechanism for transporting metals toward the surface, although ionic diffusion, electrochemical gradients, and capillary action may play a role in anomaly dispersal. Sample sites near the Rainy Lake-Seine River fault zone, a regional shear zone, often have anomalous concentrations of a variety of metals, commonly including Zn and/or one or more metals which substitute for Zn in sphalerite (Cd, Ge, Ga, and Sn). Shifts in background concentrations of Bi, Sb, and As show a trend across the area indicating a possible regional zoning of lode-Au mineralization. Soil anomalies of Ag, Co, and Tl parallel basement structures, suggesting areas that may have potential for Cobalt/Thunder Baytype silver viens. An area around Baudette, Minnesota, which is underlain by quartz-chlorite-carbonate-altered shear zones, is anomalous in Ag, As, Bi, Co, Mo, Te, Tl, and W. Anomalies of Ag, As, Bi, Te, and W tend to follow the fault zones, suggesting potential

  18. Assessing topsoil and bedrock hydrodynamic properties from natural and artificial rainfalls over a 10m2 steep plot in Cevennes area (France)

    Science.gov (United States)

    Adamovic, Marko; Bouvier, Christophe; Brunet, Pascal; Ayral, Pierre-Alain

    2016-04-01

    Flash floods are feature of Mediterranean climate characterized by heavy rainfalls in a few hours. Hydrological processes depend on both the topsoil and bedrock properties, which are still poorly known in the mountainous areas. Thus, special attention was paid to characterize the water fluxes in the shallow near-surface area. This study focuses on a 10-m2plot within a granitic hillslope in Cevennes area. Water content was monitored at several depths (up to 70cm) during both intense artificial and natural rainfall events, in order to study both infiltration and saturation processes in both extreme and normal conditions. Inverse modeling was performed in order to estimate parameters, such as θs, θr, α, n, Ks associated to the Mualem-Van Genuchten formulation, using the HYDRUS-1D software. The deep boundary condition was also calibrated to assess the properties of the deep layers. Although the topsoil depth is rather small (˜40 cm), the water storage during the rainfalls was estimated to be some hundreds millimeters, which largely exceeds the topsoil capacity. It suggests that the weathered area (and maybe the fractured rock area) below the soil, can have an active role in the water storage and sub-surface flow dynamics. Similar parameters were used to perform correct simulations under both artificial and natural rainfalls: thus artificial rainfalls enhance extreme conditions corresponding to flash floods occurrence, and the identified flux patterns are robust in natural conditions.

  19. Heavy minerals and garnet geochemistry of stream sediments and bedrocks from the Almklovdalen area, Western Gneiss Region, SW Norway: Implications for provenance analysis

    Science.gov (United States)

    Krippner, Anne; Meinhold, Guido; Morton, Andrew C.; Schönig, Jan; von Eynatten, Hilmar

    2016-05-01

    Detrital heavy minerals commonly document the geological setting in the source area, hence they are widely used in sedimentary provenance analysis. In heavy mineral studies, the 63-125 and 63-250 μm grain size fractions are most commonly used. Heavy mineral data and garnet geochemistry of stream sediments and bedrocks from the catchment area draining the Almklovdalen peridotite massif in SW Norway reveal that a wider grain size spectrum needs to be considered to avoid misleading interpretations. The Almklovdalen peridotite massif consists mainly of dunite and harzburgite, as testified by the heavy mineral suite. At the outlet of the main river, the heavy mineral spectrum is very monotonous due to dilution by a strong influx of olivine. Heavy minerals like apatite and epidote characterising the host gneisses have almost disappeared. MgO-rich almandine garnets are more frequent in the coarser grain size fractions, whereas MnO-rich almandine garnets are more frequent in the finer grain size fractions. Garnets with pyrope content exceeding 50% are only found in the 500-1000 μm grain size fraction. Therefore, the sample location and the selected grain size fraction are of paramount importance when dealing with heavy minerals and mineral geochemical data; otherwise, provenance-sensitive information may be missed.

  20. A reconnaissance spatial and temporal assessment of methane and inorganic constituents in groundwater in bedrock aquifers, Pike County, Pennsylvania, 2012-13

    Science.gov (United States)

    Senior, Lisa A.

    2014-01-01

    Pike County in northeastern Pennsylvania is underlain by the Devonian-age Marcellus Shale and other shales, formations that have potential for natural gas development. During 2012–13, the U.S. Geological Survey in cooperation with the Pike County Conservation District conducted a reconnaissance study to assess baseline shallow groundwater quality in bedrock aquifers prior to possible shale-gas development in the county. For the spatial component of the assessment, 20 wells were sampled in summer 2012 to provide data on the occurrence of methane and other aspects of existing groundwater quality throughout the county, including concentrations of inorganic constituents commonly present at low levels in shallow, fresh groundwater but elevated in brines. For the temporal component of the assessment, 4 of the 20 wells sampled in summer 2012 were sampled monthly from July 2012 through June 2013 to provide data on seasonal variability in groundwater quality. All water samples were analyzed for major ions, nutrients, selected inorganic trace constituents (including metals and other elements), stable isotopes of water, radon-222, gross alpha- and gross beta-particle activity, dissolved gases (methane, ethane, and ethene), and, if possible, isotopic composition of methane. Additional analyses for boron and strontium isotopes, age-dating of water, and radium-226 were done on water samples collected from six wells in June 2013.

  1. Effects of Bedrock Lithology and Subglacial Till on the Motion of Ruth Glacier, Alaska, Deduced from Five Pulses from 1973-2012

    Science.gov (United States)

    Turrin, J.; Forster, R.; Sauber, Jeanne; Hall, Dorothy K.; Bruhn, R.

    2013-01-01

    A pulse is a type of unstable glacier flow intermediate between normal flow and surging. Using Landsat MSS, TM, and ETM+ imagery and feature tracking software, a time-series of mostly annual velocity maps from 1973 to 2012 was produced that reveals five pulses of Ruth Glacier, Alaska. Peaks in ice velocity were found in the 1981, 1989, 1997, 2003, and 2010; approximately every 7 years. During these peak years the ice velocity increased 300%, from approximately 40 m/yr to 160 m/yr, and occurred in an area of the glacier underlain by sedimentary bedrock. Based on the spatio-temporal behavior of Ruth Glacier during the pulse cycles, we suggest the pulses are due to enhanced basal motion via deformation of a subglacial till. The cyclical nature of the pulses is theorized to be due to a thin till, with low permeability, that causes incomplete drainage of the till between the pulses, followed by eventual recharge and dilation of the till. These findings suggest care is needed when attempting to correlate changes in regional climate with decadal-scale changes in velocity, because in some instances basal conditions may have a greater influence on ice dynamics than climate.

  2. New constraints on paleo-denudation history of the Ladakh Batholith - applying bedrock and detrital apatite (U-Th-Sm)/He thermochronology

    Science.gov (United States)

    Sahragard Sohi, Mohammad; Rosenkranz, Ruben; Spiegel, Cornelia

    2015-04-01

    The Ladakh Batholith is part of the Transhimalayan Plutonic Belt and records the early exhumation history of the Himalayan orogen. The evolution of the Ladakh Batholith is complex and was controversially discussed in the literature (see Kirstein, 2011 for details). Recent data by Kirstein et al. (2006 & 2009) suggest a trend of exhumation rates across the batholith, with earlier exhumation along its southern margin and later exhumation in the north. Apart from methodological purpose aimed at refining the apatite (U-Th-Sm)/He technique, the goal of our study is to investigate the earliest denudation history of the Ladakh Pluton and thereby that of the Himalayan orogen, using apatite (U-Th-Sm)/He thermochronology (i) applied to bedrocks from the southern margin of the batholith, and (ii) to sediments from the adjacent Upper Indian Group sediments such as Nurla, Choksti, and Nimu Formations with Early Eocene to Late Miocene in age (Henderson et al., 2010). These sediments are thought to be sourced from the Ladakh Batholith (Henderson et al., 2011). Apatite (U-Th-Sm)/He dating is sensitive to temperatures between ~85 and 40°C and thus to geodynamic movements of the upper ~1.5 to 3 km of the earth's crust. While thermochronology data from present-day bedrock exposures provides denudation rates integrated over the time between cooling age and the present, the earlier denudation history is eroded away from the present exposures and stored in the syn-tectonic sediments. Thus, dating sediments of the Indian Group will yield the paleo-denudation history of the (southern) Ladakh area, including changes of denudation rates back through time. This will reveal new insights into the relation between tectonics, climate, and erosion. References Henderson, A. L., Y. Najman, R. Parrish, M. BouDagher - Fadel, D. Barford, E. Garzanti, and S. Andò (2010), Geology of the Cenozoic Indus Basin sedimentary rocks: Paleoenvironmental interpretation of sedimentation from the western Himalaya

  3. Geophysical and hydrogeological characterisation of the impacts of on-site wastewater treatment discharge to groundwater in a poorly productive bedrock aquifer.

    Science.gov (United States)

    Donohue, Shane; McCarthy, Valerie; Rafferty, Patrick; Orr, Alison; Flynn, Raymond

    2015-08-01

    Contaminants discharging from on-site wastewater treatment systems (OSWTSs) can impact groundwater quality, threatening human health and surface water ecosystems. Risk of negative impacts becomes elevated in areas of extreme vulnerability with high water tables, where thin unsaturated intervals limit vadose zone attenuation. A combined geophysical/hydrogeological investigation into the effects of an OSWTS, located over a poorly productive aquifer (PPA) with thin subsoil cover, aimed to characterise effluent impacts on groundwater. Groundwater, sampled from piezometers down-gradient of the OSWTS percolation area displayed spatially erratic, yet temporally consistent, contaminant distributions. Electrical resistivity tomography identified an area of gross groundwater contamination close to the percolation area and, when combined with seismic refraction and water quality data, indicated that infiltrating effluent reaching the water table discharged to a deeper more permeable zone of weathered shale resting on more competent bedrock. Subsurface structure, defined by geophysics, indicated that elevated chemical and microbiological contaminant levels encountered in groundwater samples collected from piezometers, down-gradient of sampling points with lower contaminant levels, corresponded to those locations where piezometers were screened close to the weathered shale/competent rock interface; those immediately up-gradient were too shallow to intercept this interval, and thus the more impacted zone of the contaminant plume. Intermittent occurrence of faecal indicator bacteria more than 100m down gradient of the percolation area suggested relatively short travel times. Study findings highlight the utility of geophysics as part of multidisciplinary investigations for OSWTS contaminant plume characterisation, while also demonstrating the capacity of effluent discharging to PPAs to impact groundwater quality at distance. Comparable geophysical responses observed in similar

  4. Geophysical and hydrogeological characterisation of the impacts of on-site wastewater treatment discharge to groundwater in a poorly productive bedrock aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Donohue, Shane [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, Northern Ireland (United Kingdom); McCarthy, Valerie; Rafferty, Patrick [Department of Applied Sciences, Dundalk Institute of Technology, Dublin Road, Dundalk (Ireland); Orr, Alison; Flynn, Raymond [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, Northern Ireland (United Kingdom)

    2015-08-01

    Contaminants discharging from on-site wastewater treatment systems (OSWTSs) can impact groundwater quality, threatening human health and surface water ecosystems. Risk of negative impacts becomes elevated in areas of extreme vulnerability with high water tables, where thin unsaturated intervals limit vadose zone attenuation. A combined geophysical/hydrogeological investigation into the effects of an OSWTS, located over a poorly productive aquifer (PPA) with thin subsoil cover, aimed to characterise effluent impacts on groundwater. Groundwater, sampled from piezometers down-gradient of the OSWTS percolation area displayed spatially erratic, yet temporally consistent, contaminant distributions. Electrical resistivity tomography identified an area of gross groundwater contamination close to the percolation area and, when combined with seismic refraction and water quality data, indicated that infiltrating effluent reaching the water table discharged to a deeper more permeable zone of weathered shale resting on more competent bedrock. Subsurface structure, defined by geophysics, indicated that elevated chemical and microbiological contaminant levels encountered in groundwater samples collected from piezometers, down-gradient of sampling points with lower contaminant levels, corresponded to those locations where piezometers were screened close to the weathered shale/competent rock interface; those immediately up-gradient were too shallow to intercept this interval, and thus the more impacted zone of the contaminant plume. Intermittent occurrence of faecal indicator bacteria more than 100 m down gradient of the percolation area suggested relatively short travel times. Study findings highlight the utility of geophysics as part of multidisciplinary investigations for OSWTS contaminant plume characterisation, while also demonstrating the capacity of effluent discharging to PPAs to impact groundwater quality at distance. Comparable geophysical responses observed in similar

  5. Corrosion of copper in oxygen-deficient groundwater with and without deep bedrock micro-organisms: Characterisation of microbial communities and surface processes

    Science.gov (United States)

    Huttunen-Saarivirta, E.; Rajala, P.; Bomberg, M.; Carpén, L.

    2017-02-01

    Copper specimens were exposed to oxygen-deficient artificial groundwater in the presence and absence of micro-organisms enriched from the deep bedrock of the planned nuclear waste repository site at Olkiluoto island on the western coast of Finland. During the exposure periods of 4 and 10 months, the copper specimens were subjected to electrochemical measurements. The biofilm developed on the specimens and the water used in the exposures were subjected to microbiological analyses. Changes in the water chemistry were also determined and surfaces of the copper specimens were characterized with respect to the morphology and composition of the formed corrosion products. The results showed that under biotic conditions, redox of the water and open circuit potential (OCP) of the copper specimens were generally negative and resulted in the build-up of a copper sulphide, Cu2S, layer due to the activity of sulphate-reducing bacteria (SRB) that were included in the system. In the 4-month test, the electrochemical behaviour of the specimens changed during the exposure and alphaproteobactria Rhizobiales were the dominant bacterial group in the biofilm where the highest corrosion rate was observed. In the 10-month test, however, deltaproteobacteria SRB flourished and the initial electrochemical behaviour and the low corrosion rate of the copper were retained until the end of the test period. Under abiotic conditions, the positive water redox potential and specimen OCP correlated with the formation of copper oxide, Cu2O. Furthermore, in the absence of SRB, Cu2O provided slightly inferior protection against corrosion compared to that by Cu2S in the presence of SRB. The obtained results show that the presence of microorganisms may enhance the passivity of copper. In addition, the identification of key microbial species, such as SRB thriving on copper for long time periods, is important for successful prediction of the behaviour of copper.

  6. Preliminary report on mercury geochemistry of placer gold dredge tailings, sediments, bedrock, and waters in the Clear Creek restoration area, Shasta County, California

    Science.gov (United States)

    Ashley, Roger P.; Rytuba, James J.; Rogers, Ronald; Kotlyar, Boris B.; Lawler, David

    2002-01-01

    Clear Creek, one of the major tributaries of the upper Sacramento River, drains the eastern Trinity Mountains. Alluvial plain and terrace gravels of lower Clear Creek, at the northwest edge of the Sacramento Valley, contain placer gold that has been mined since the Gold Rush by various methods including dredging. In addition, from the 1950s to the 1980s aggregate-mining operations removed gravel from the lower Clear Creek flood plain. Since Clear Creek is an important stream for salmon production, a habitat restoration program is underway to repair damage from mining and improve conditions for spawning. This program includes using dredge tailings to fill in gravel pits in the flood plain, raising the concern that mercury lost to these tailings in the gold recovery process may be released and become available to biota. The purposes of our study are to determine concentrations and speciation of mercury in sediments, tailings, and water in the lower Clear Creek area, and to determine its mobility. Mercury concentrations in bedrock and unmined gravels both within and above the mined area are low, and are taken to represent background concentrations. Bulk mercury values in flood-plain sediments and dry tailings are elevated to several times these background concentrations. Mercury in sediments and tailings is associated with fine size fractions. Although methylmercury levels are generally low in sediments, shallow ponds in the flood plain may have above-normal methylation potential. Stream waters in the area show low mercury and methylmercury levels. Ponds with elevated methylmercury in sediments have more methylmercury in their waters as well. One seep in the area is highly saline, and enriched in mercury, lithium, and boron, similar to connate waters that are expelled along thrust faults to the south on the west side of the Sacramento Valley. This occurrence suggests that mercury in waters may at least in part be from sources other than placer mining.

  7. Unpublished Digital Bedrock Geology Map of Herbert Hoover National Historic Site and Vicinity, Iowa (NPS, GRD, GRI, HEHO, HHBR digital map) adapted from Iowa Geological Survey Open-File Report Maps by Witzke et. al. (2010) and Witzke and Anderson (2008)

    Data.gov (United States)

    National Park Service, Department of the Interior — The Unpublished Digital Bedrock Geology Map of Herbert Hoover National Historic Site and Vicinity, Iowa is composed of GIS data layers complete with ArcMap 9.3 layer...

  8. Geology, Bedrock, Surficial and geologic hazard map of the NPS Blue Ridge Parkway corridor. Majority of central and southern segments completed with entire project completed by October 2008., Published in 2004, 1:12000 (1in=1000ft) scale, NC DENR / Div. of Land Resources / Geological Survey Section.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geology, Bedrock dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from Field Survey/GPS information as of 2004. It is described as...

  9. Site investigation SFR. Bedrock geology

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Philip; Markstroem, Ingemar (Golder Associates AB (Sweden)); Petersson, Jesper (Vattenfall Power Consultant AB (Sweden)); Triumf, Carl-Axel; Isaksson, Hans; Mattsson, Haakan (GeoVista AB (Sweden))

    2011-12-15

    SKB is currently carrying out an assessment of the future extension of the final repository for low and middle level radioactive operational waste, SFR. The planned SFR extension lies at a relatively shallow depth (-50 to -200 masl) compared with the planned Forsmark facility for spent nuclear fuel (-400 to -500 masl). The main aim of the multidisciplinary modelling project involving geology, hydrogeology, hydrogeochemistry and rock mechanical modelling is to describe the rock volume for the planned extension of SFR that was presented in /SKB 2008a/. The results of the modelling project in the form of a forthcoming site descriptive model will supply the basis for site-adapted design including engineering characteristics, in addition to a general assessment of the site suitability. The current report presents the results of the geological work with the deterministic rock domain and deformation zone models (version 1.0) and forms a basis for the three other disciplines in the modelling work. The shallow depth of SFR and its proposed extension means that the facility lies partly within the rock volume affected by the effects of stress release processes during loading and unloading cycles, with an associated increased frequency of open sub-horizontal fractures in the near-surface realm (above -150 masl) compared with that observed at greater depths. The main report describes the data input to the modelling work, the applied modelling methodology and the overall results. More detailed descriptions of the individual modelled deformation zones and rock domains are included in the appendices. The geological modelling work during version 1.0 follows SKB's established methodology using the Rock Visualisation System (RVS). The deformation zone model version 1.0 is a further development of the previous version 0.1 /Curtis et al. 2009/. While the main input to deformation zone model version 0.1 was older geological data from the construction of SFR, including drawings of the geological tunnel mapping and eleven drill cores remapped according to the Boremap system, input to model version 1.0 has included the results from eight new cored boreholes as well as a fuller integration of Forsmark site investigation data, a further more extensive review of the drill core from an additional 32 boreholes associated with the construction of the existing SFR facility and an updated mapping of the lower construction tunnel. The current modelling work has also reviewed the older SFR data and models. While details concerning the earlier zones lying in immediate contact with the existing SFR facility have been changed, the earlier overall position, orientation and number of these deformation zones is maintained. A significant difference concerns their thickness due to the contrasting methodologies used during the different campaigns. In SFR model version 0.1, a single deformation zone model was produced, with a volume corresponding to the regional model volume. The model contained all the deformation zones modelled irrespective of size. Separate local and regional deformation zone models have been produced in SFR model version 1.0, following resolution criteria for the different model volumes. The local model contains zones with a minimum size of 300 m, while the regional model has structures that have a minimum size constraint of 1,000 m trace length at the ground surface. The selection of these size limits is related to the model volume maximum depth (local model -300 masl and regional model -1,000 masl) and the applied methodology that requires the same model resolution throughout the defined model volume (see Section 5.3.1). To assist hydrogeological modelling work, an updated combined model, including all structures from both the regional and local models, has also been delivered. The existing SFR facility and the rock volume directly to the south-east, which is proposed for the new facility extension, lies within a tectonic block that is bounded to the north-east and south-west by two broad belts of concentrated ductile and brittle deforma

  10. Taste: The Bedrock of Flavor

    OpenAIRE

    Beauchamp, Gary K.

    2014-01-01

    The significance of taste for human health:Throughout most of human evolution, the daily decisions of what to put into ones mouth and swallow and what to reject presented challenges fraught with danger. Energy-rich foods were often difficult to find; protein was in short supply; sodium was scarce. Moreover, many plants that did contain nutrients were also equipped with defensive compounds that were poisonous. Now many humans over consume exactly the foods that they evolved to find particu...

  11. Taste: The Bedrock of Flavor

    Directory of Open Access Journals (Sweden)

    Gary K Beauchamp

    2014-07-01

    There are two general approaches to reducing dietary sodium. First, there is considerable interest in developing salt substitutes and salt enhancers. Potassium chloride is widely used (usually in combination with NaCl as a substitute but it is not ideal since many find it has an unpleasant off-taste. There is considerable academic and industry research to identify new substitutes but to date there are none for salty as there are for sweet taste. A second approach to lowering sodium intake on a population-wide level in the United States, where more than 80% of the average person’s salt intake comes from food purchased and not from being added during cooking or at the table, is for food manufacturers and restaurants to gradually reduce the amount of salt in prepared foods. Experimental studies have demonstrated that if one reduces salt intake preferences for salt are similarly reduced. Based on this, the Institute of Medicine (IOM recommended that the Food and Drug Administration require gradual reduction by food manufacturers and large restaurant chains (IOM. The FDA has not acted on this recommendation. Conclusion. As illustrated by the difficulties in reducing salt in spite of the health benefits (a similar set of arguments for reducing excess consumption of carbohydrate sugars could be made, the sense of taste is a powerful driver of food intake. A deeper understanding of this important but neglected sensory system is required if we are to adequately address critical health problems in modern society that are often driven by excess consumption of tasty nutrients.

  12. Site investigation SFR. Bedrock geology

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Philip; Markstroem, Ingemar (Golder Associates AB (Sweden)); Petersson, Jesper (Vattenfall Power Consultant AB (Sweden)); Triumf, Carl-Axel; Isaksson, Hans; Mattsson, Haakan (GeoVista AB (Sweden))

    2011-12-15

    SKB is currently carrying out an assessment of the future extension of the final repository for low and middle level radioactive operational waste, SFR. The planned SFR extension lies at a relatively shallow depth (-50 to -200 masl) compared with the planned Forsmark facility for spent nuclear fuel (-400 to -500 masl). The main aim of the multidisciplinary modelling project involving geology, hydrogeology, hydrogeochemistry and rock mechanical modelling is to describe the rock volume for the planned extension of SFR that was presented in /SKB 2008a/. The results of the modelling project in the form of a forthcoming site descriptive model will supply the basis for site-adapted design including engineering characteristics, in addition to a general assessment of the site suitability. The current report presents the results of the geological work with the deterministic rock domain and deformation zone models (version 1.0) and forms a basis for the three other disciplines in the modelling work. The shallow depth of SFR and its proposed extension means that the facility lies partly within the rock volume affected by the effects of stress release processes during loading and unloading cycles, with an associated increased frequency of open sub-horizontal fractures in the near-surface realm (above -150 masl) compared with that observed at greater depths. The main report describes the data input to the modelling work, the applied modelling methodology and the overall results. More detailed descriptions of the individual modelled deformation zones and rock domains are included in the appendices. The geological modelling work during version 1.0 follows SKB's established methodology using the Rock Visualisation System (RVS). The deformation zone model version 1.0 is a further development of the previous version 0.1 /Curtis et al. 2009/. While the main input to deformation zone model version 0.1 was older geological data from the construction of SFR, including drawings of the geological tunnel mapping and eleven drill cores remapped according to the Boremap system, input to model version 1.0 has included the results from eight new cored boreholes as well as a fuller integration of Forsmark site investigation data, a further more extensive review of the drill core from an additional 32 boreholes associated with the construction of the existing SFR facility and an updated mapping of the lower construction tunnel. The current modelling work has also reviewed the older SFR data and models. While details concerning the earlier zones lying in immediate contact with the existing SFR facility have been changed, the earlier overall position, orientation and number of these deformation zones is maintained. A significant difference concerns their thickness due to the contrasting methodologies used during the different campaigns. In SFR model version 0.1, a single deformation zone model was produced, with a volume corresponding to the regional model volume. The model contained all the deformation zones modelled irrespective of size. Separate local and regional deformation zone models have been produced in SFR model version 1.0, following resolution criteria for the different model volumes. The local model contains zones with a minimum size of 300 m, while the regional model has structures that have a minimum size constraint of 1,000 m trace length at the ground surface. The selection of these size limits is related to the model volume maximum depth (local model -300 masl and regional model -1,000 masl) and the applied methodology that requires the same model resolution throughout the defined model volume (see Section 5.3.1). To assist hydrogeological modelling work, an updated combined model, including all structures from both the regional and local models, has also been delivered. The existing SFR facility and the rock volume directly to the south-east, which is proposed for the new facility extension, lies within a tectonic block that is bounded to the north-east and south-west by two broad belts of concentrated ductile and brittle deformation (Figures S-1 and S-2). The central block is less affected by deformation than the bounding belts. Within the central block, in the rock volume for the planned extension, a series of WNW-NW trending deformation zones are included in the local model (Figure S-2). These are much smaller than the bounding belts and were initiated at a later stage in a brittle regime. Even smaller zones with the same general strike and character, below the current model resolution, are inferred to permeate the entire rock volume. A NE to ENE striking set of brittle deformation zones is also present (Figure S-2). Compared with the WNW-NW set they are generally thinner and shorter, due to termination against the broad WNW-NW trending deformation belts

  13. Cells

    Directory of Open Access Journals (Sweden)

    Zhao-Hui Jin

    2012-11-01

    Full Text Available As cancer stem cells (CSCs are postulated to play critical roles in cancer development, including metastasis and recurrence, CSC imaging would provide valuable information for cancer treatment and lead to CSC-targeted therapy. To assess the possibility of in vivo CSC targeting, we conducted basic studies on radioimmunotargeting of cancer cells positive for CD133, a CSC marker recognized in various cancers. Antibodies against CD133 were labeled with 125I, and their in vitro cell binding properties were tested. Using the same isotype IgG as a control, in vivo biodistribution of the labeled antibody retaining immunoreactivity was examined in mice bearing an HCT116 xenograft in which a population of the cancer cells expressed CD133. Intratumoral distribution of the labeled antibody was examined and compared to the CD133 expression pattern. The 125I-labeled anti-CD133 antibody showed a modest but significantly higher accumulation in the HCT116 xenograft compared to the control IgG. The intratumoral distribution of the labeled antibody mostly overlapped with the CD133 expression, whereas the control IgG was found in the area close to the necrotic tumor center. Our results indicate that noninvasive in vivo targeting of CSCs could be possible with radiolabeled antibodies against cell membrane markers.

  14. Transport of Bacteria and Virus-Sized Particles and Bacteriophage from Ground Surface to Depth in a Bedrock Aquifer - A Field Experiment

    Science.gov (United States)

    Novakowski, K. S.; Trimper, S.; Praamsma, T.; Springthorpe, S.

    2010-12-01

    Shallow, unprotected bedrock aquifers are common sources of drinking water supply in eastern North America. The vulnerability of these aquifers to contamination from pathogens is widely recognised, although little is actually known about the transport processes involved, particularly where the source is located near to or on ground surface (i.e. a septic system). In this experiment we explore the transport of fluorescent microspheres having diameters of 1.75 and 0.3 µm and the bacteriophage Φ-X174 in a sparsely-fractured gneissic terrain having minimal overburden cover. The experiment was conducted by ponding water in a 7 m2 area on the edge of an outcrop having observable vertical fractures and measuring the arrival of particles in two nearby monitoring wells. A conservative solute tracer (Lissamine FF) was also used to follow the solute front. In order to encourage transport to the wells and to provide a discharge stream to sample, pumping was conducted at a rate of 7.7 L/min from the lower half of the 15-m deep well farthest from the pond (approximately 7 m away). Sampling was conducted from the pumping stream, the upper 5 m of that well and the upper 5 m of an additional well located about 5 m from the surface pond. The experiment was conducted over a 48 hr period and samples were obtained every 15 min initially declining to once every 2 hrs towards the end of the experiment. Analysis of the bacteriophage was conducted using the Double Agar Layer method and the concentration of microspheres was determined using epi-fluorescent microscopy. As the latter is very time consuming, only preliminary results are available for the microsphere transport. The results show widespread migration of both the microspheres and the bacteriophage, as arrival in all sampling locations was detected. Mass recovery was low but similar for both the bacteriophage and the solute tracer, although the majority of the bacteriophage arrived much earlier than the majority of the solute

  15. The Regional Geochemistry of Soils and Willow in a Metamorphic Bedrock Terrain, Seward Peninsula, Alaska, 2005, and Its Possible Relation to Moose

    Science.gov (United States)

    Gough, L.P.; Lamothe, P.J.; Sanzolone, R.F.; Drew, L.J.; Maier, J.A.K.

    2009-01-01

    ' and the 'among sites at a location' GLM levels. Most of the variation in concentrations of Cd in soils occurred among sites (separated by 0.5 km) at both locations across all soil horizons and not between the two locations. Cd distribution across the landscape may be due to variation in soil mineralogy, especially the amount of graphite in soil, which has been associated with Cd. Although samples were collected on the same geologic unit, the geochemistry of soils was demonstrated to be uniform with depth but highly variable between locations separated by 80 km. This exploratory study establishes the presence of elevated levels of Cd in willow growing over Paleozoic bedrock in the Seward Peninsula. Further work is needed to definitively link these high Cd levels in willow browse to the health of moose.

  16. Comparison of methods for estimating ground-water recharge and base flow at a small watershed underlain by fractured bedrock in the Eastern United States

    Science.gov (United States)

    Risser, Dennis W.; Gburek, William J.; Folmar, Gordon J.

    2005-01-01

    This study by the U.S. Geological Survey (USGS), in cooperation with the Agricultural Research Service (ARS), U.S. Department of Agriculture, compared multiple methods for estimating ground-water recharge and base flow (as a proxy for recharge) at sites in east-central Pennsylvania underlain by fractured bedrock and representative of a humid-continental climate. This study was one of several within the USGS Ground-Water Resources Program designed to provide an improved understanding of methods for estimating recharge in the eastern United States. Recharge was estimated on a monthly and annual basis using four methods?(1) unsaturated-zone drainage collected in gravity lysimeters, (2) daily water balance, (3) water-table fluctuations in wells, and (4) equations of Rorabaugh. Base flow was estimated by streamflow-hydrograph separation using the computer programs PART and HYSEP. Estimates of recharge and base flow were compared for an 8-year period (1994-2001) coinciding with operation of the gravity lysimeters at an experimental recharge site (Masser Recharge Site) and a longer 34-year period (1968-2001), for which climate and streamflow data were available on a 2.8-square-mile watershed (WE-38 watershed). Estimates of mean-annual recharge at the Masser Recharge Site and WE-38 watershed for 1994-2001 ranged from 9.9 to 14.0 inches (24 to 33 percent of precipitation). Recharge, in inches, from the various methods was: unsaturated-zone drainage, 12.2; daily water balance, 12.3; Rorabaugh equations with PULSE, 10.2, or RORA, 14.0; and water-table fluctuations, 9.9. Mean-annual base flow from streamflow-hydrograph separation ranged from 9.0 to 11.6 inches (21-28 percent of precipitation). Base flow, in inches, from the various methods was: PART, 10.7; HYSEP Local Minimum, 9.0; HYSEP Sliding Interval, 11.5; and HYSEP Fixed Interval, 11.6. Estimating recharge from multiple methods is useful, but the inherent differences of the methods must be considered when comparing

  17. Use of stereoscopic satellite imagery for 3D mapping of bedrock structure in West Antarctica: An example from the northern Ford Ranges

    Science.gov (United States)

    Contreras, A.; Siddoway, C. S.; Porter, C.; Gottfried, M.

    2012-12-01

    differentiation on the margin of the Gondwana supercontinent, but the methods that we here employ are broadly applicable for a wide variety of rock types in remote and inaccessible localities in the polar regions. A further use of the DEMs + imagery are for mapping of regional-scale subglacial bedrock faults and geological contacts in the region, of potential significance for interpretation of GPS and seismic data being recorded at Mt. Carbone in the ANET/POLEnet array. Prior research identified a lithospheric-scale fault that separates the Fosdick Mountains from Mt Carbone in the Phillips range. The pronounced contrast in rock type and cooling history, steep magnetic and gravity gradients, and the presence of the west-flowing Balchen Glacier provide evidence for the fault, which is concealed by glacier ice. Accurate determination of the fault location and lateral extent may be important for interpretation of regional patterns of post-glacial response and/or neotectonics based on GPS+seismic data being collected by ANET/POLEnet in West Antarctica.

  18. Mercury Geochemistry of Gold Placer Tailings, Sediments, Bedrock, and Waters in the Lower Clear Creek Area, Shasta County, California - Report of Investigations, 2001-2003

    Science.gov (United States)

    Ashley, Roger P.; Rytuba, James J.

    2008-01-01

    Clear Creek, one of the major tributaries of the upper Sacramento River, drains the eastern Trinity Mountains. Alluvial plain and terrace gravels of lower Clear Creek, at the northwest edge of the Sacramento Valley, contain placer gold that has been mined since the Gold Rush by various methods including hydraulic mining and dredging. In addition, from the 1950s to the 1980s aggregate-mining operations removed gravel from the lower Clear Creek flood plain. Since Clear Creek is an important stream for salmon production, a habitat restoration program is underway to repair damage from mining and improve conditions for spawning. This program includes moving dredge tailings to increase the area of spawning gravel and to fill gravel pits in the flood plain, raising the concern that mercury lost to these tailings in the gold recovery process may be released and become available to biota. The purposes of our study are to identify sources, transport, and dispersal of mercury in the lower Clear Creek area and identify environments in which bioavailable methylmercury is produced. Analytical data acquired include total mercury and methylmercury concentrations in sediments, tailings, and water. Mercury concentrations in bedrock and unmined gravels in and around the mined area are low and are taken to represent background concentrations. Bulk mercury values in placer mining tailings range from near-background in coarse dry materials to more than 40 times background in sands and silts exposed to mercury in sluices. Tailings are entrained in flood-plain sediments and active stream sediments; consequently, mercury concentrations in these materials range from background to about two to three times background. Mercury in sediments and tailings is associated with fine size fractions. The source of most of this mercury is historical gold mining in the Clear Creek watershed. Although methylmercury levels are low in most of these tailings and sediments, flood-plain sediment in shallow

  19. Factors Affecting Specific-Capacity Tests and their Application--A Study of Six Low-Yielding Wells in Fractured-Bedrock Aquifers in Pennsylvania

    Science.gov (United States)

    Risser, Dennis W.

    2010-01-01

    This report by the U.S. Geological Survey, prepared in cooperation with the Pennsylvania Department of Environmental Protection, Bureau of Mining and Reclamation, evaluates factors affecting the application of specific-capacity tests in six low-yielding water wells in areas of coal mining or quarrying in Pennsylvania. Factors such as pumping rate, duration of pumping, aquifer properties, wellbore storage, and turbulent flow were assessed by theoretical analysis and by completing multiple well tests, selected to be representative of low-yielding household-supply wells in areas of active coal mining or quarrying. All six wells were completed in fractured-bedrock aquifers--five in coal-bearing shale, siltstone, sandstone, limestone, and coal of Pennsylvanian and Permian age and one in limestone of Cambrian age. The wells were pumped 24 times during 2007-09 at rates from 0.57 to 14 gallons per minute during tests lasting from 22 to 240 minutes. Geophysical logging and video surveys also were completed to determine the depth, casing length, and location of water-yielding zones in each of the test wells, and seasonal water-level changes were measured during 2007-09 by continuous monitoring at each well. The tests indicated that specific-capacity values were reproducible within about ? 20 percent if the tests were completed at the same pumping rate and duration. A change in pumping duration, pumping rate, or saturated aquifer thickness can have a substantial effect on the comparability of repeated tests. The largest effect was caused by a change in aquifer thickness in well YO 1222 causing specific capacity from repeated tests to vary by a factor of about 50. An increase in the duration of pumping from 60 to 180 minutes caused as much as a 62 percent decrease in specific capacity. The effect of differing pumping rates on specific capacity depends on whether or not the larger rate causes the water level in the well to fall below a major water-yielding zone; when this

  20. Application Research on Hydraulic Fracturing Technology for Bedrock Geothermal Yield Increasing in Western Henan%水力压裂技术在豫西基岩地热井增产中的应用研究

    Institute of Scientific and Technical Information of China (English)

    申云飞; 卢玮; 陈莹; 程存平

    2016-01-01

    地热资源是清洁能源,其开发利用主要通过钻井工程来实现。地热资源量(水量)大小决定着开发利用的价值。实际中,因地层等条件的复杂和不确定性,导致地热井出水量和温度不能达到预期的目标。特别是在山区基岩缺水地区地热资源开发,由于水量和温度指标偏低,严重影响了清洁能源的开发利用。本文结合工程实例,首次在豫西基岩严重缺水地区通过压裂车和钻井泵分段水力压裂技术,使低产地热井出水量增加3倍,达到了预期的目的。为今后基岩地区地热和地下水资源开发利用增产提供了借鉴。%Geothermal energy is a clean energy source;its development and utilization are mainly realized by drilling engi-neering, and the value of development and utilization are determined by the amount of geothermal resources (water yield). In practice, due to the complexity and uncertainty of the stratum, the water yield and water temperature can not reach the expectation, especially in water-shortage mountainous bedrock area, development and utilization of clean energy source are seriously affected by low water yield and temperature indexes.Staged hydraulic fracturing technology by using fracturing truck and drilling pump is applied in serious water shortage area of Westen Henan for the first time, water output grows 3 times for low yield geothermal well and reached the expected target.It can provide reference for the future development and utilization of geothermal and groundwater resources in the bedrock area.

  1. NEEM计划2537.36m透底深冰芯的钻取与成果概述%An Ice Core to Bedrock, 2 537.36 m in Depth,of the NEEM International Project

    Institute of Scientific and Technical Information of China (English)

    王士猛; 效存德; 谢爱红; 李传金; 任贾文《中文作者七》=秦大河《中文作者八》=张通

    2011-01-01

    NEEM(格陵兰北部Eemian冰芯钻取)计划是目前最重要的国际冰芯研究计划,来自14个国家超过300名的科学家参与,目标是获得130~115 ka BP甚至更古老的Eemian间冰期的透底冰芯和气候信息;此冰芯长达2 537.36 m,最后2m冰芯含有数十万年的基岩和其他物质.介绍了NEEM计划深冰芯的钻取背景和NEEM计划概况,以及NEEM计划获取的成果,并详述我国科学家在2010年度深冰芯钻取过程中取得的认识.%More than 300 scientists from 14 nations have participated in NEEM Project(the North Greenland Eemian Ice Core Drilling Project),the most international ice core effort to date.And the NEEM project has recovered the ica from the warm Eemian Interglacial Period, 130 000 to 115 000 a BP and even more.The core has 2 537.36 m in length,and the last 2 m above the bedrock contains rocks and other material that have not exposed for hundreds of thousands of years.In this paper,the background and outline of the project are briefly introduced,together with some experiences during the drilling and the 2011 NEEM field plan.

  2. Experimental research on seismic failure mode and supporting for slope of bedrock and overburden layer%地震力作用下基覆边坡模型试验研究

    Institute of Scientific and Technical Information of China (English)

    赵安平; 冯春; 李世海; 艾畅; 刘洋

    2012-01-01

    以汶川灾区实地考察资料为背景,选择宇宫庙滑坡为参照,制作了模型试验台,在量纲分析的基础上,对主要参数做了相似理论研究,并采用水下爆炸的方式来模拟地震波(近场)进行了大量模型试验.结果表明:基覆边坡在地震力作用下的破坏模式是浅表层张拉而导致表层松散体流坍,且地震加速度随着药量(地震烈度)的增加而呈递增趋势,重力墙、桩板墙等支挡结构对于基覆边坡的作用明显.其结论将为铁路、公路沿线的高陡边坡分析和研究提供一定的依据.%According to the site investigation of Wenchuan disaster area's statistics data as the background, the experiment model is made selecting Yugongmiao slope as the reference. The similarities of main parameters are analyzed based on dimensional analysis. The underwater blasting is used to simulate seismic wave (near-field), and a large number of model tests are conducted. The results show that the failure model of bedrock and overburden layer slope under seismic loading is surface loose media flowing caused by the tension of superficial layer, and with the increase of explosives (seismic intensity), seismic accelerations increase. It is very useful to design of gravity retaining wall and pile-wall structures. These conclusions can provide some bases for analysis and research of high-steep slopes along railways and highways.

  3. Three-dimensional numerical simulation of curtain grouting in the dam bedrock based on binghamian grouts%大坝基岩帷幕宾汉姆浆液灌浆的三维数值模拟

    Institute of Scientific and Technical Information of China (English)

    邓韶辉; 王晓玲; 敖雪菲; 任炳昱; 李瑞金

    2016-01-01

    Because of the grouting engineering of masking and the complexity of geological conditions, how to accurately determine the diffusion regularity of grout under complicated geological conditions is the key and difficult point of grouting numerical simulation analysis. Binghamian grouts two-phase flow characteris⁃tics in the process of grout diffusion and complex geological conditions of dam bedrock is not considered in the present numerical simulation research of grouting in the hydraulic engineering. These research objects mainly focus on a single fracture or a single grout hole, while the simulation of grout front has not in⁃volved. Aim at the above-mentioned problems,a three-dimensional refined geological information model,in⁃cluded different formations,unfavorable geological body, curtains, grouting holes, was firstly established in this paper. Then, coupled with the volume of fluid (VOF) method in the CFD commercial software STAR-CCM+, a three-dimensional grouting mathematical model of Binghamian grouts air-grout two-phase flow was developed to achieve the numerical simulation of the multiple holes and sequencing grouting in the dam bedrock,also analyzing the grout diffusion rule and curtain lap after grouting. Finally,a hydropow⁃er station of bedrock curtain grouting process was taken as a case. The results show that the grout diffu⁃sion radius increases with time in a certain time range,but its rate of change shows a decline trend. After grouting completion of each sequence hole,grout front laps well. Furthermore,comparing the simulation val⁃ue with the actual measuring value of the grouting quantity and time, the average errors were 9.08% and 6.32% respectively,which verified the reliability of the method.%由于灌浆工程的掩蔽性和地质条件的复杂性,如何准确地确定复杂地质条件下浆液的扩散规律是灌浆数值模拟分析的关键及难点。目前,在水利工程中灌浆数值模拟的

  4. 安徽百善煤矿超薄基岩区地质特征及对煤层安全开采影响%Geological Characteristics and Impacts on Coal Seam Safe Working in Ultra-thin Bedrock Area, Baishan Coalmine, Anhui

    Institute of Scientific and Technical Information of China (English)

    周增强; 张枫林

    2013-01-01

    百善煤矿64采区超薄基岩区域地质储量210万t,基岩厚度均小于20m,对安全回采造成了巨大影响。在分析煤矿主采煤层赋存、顶板岩石力学地质特征及水文地质条件的基础上,重点分析了超薄风化基岩及松散层内含(隔)水层的岩石特征及强风化岩石泥化对工作面开采的影响。以理论计算、现场实测数据和开采实践为依据,重点研究分析了风化基岩和含(隔)水层的物理特征及强风化岩石泥化对“两带”发育高度的影响,并设计了合理的安全保护煤柱。实践表明:超薄基岩区域强风化岩石软弱、泥化、风化对工作面回采“两带”发育高度有降低作用,有利于工作面的安全回采。%The ultra-thin bedrock area in No.64 winning district, Baishan coalmine has geological reserves 2.10 million tons, with bed-rock thickness less than 20m, thus seriously impacts safe winning. Based on main mineable coal seams hosting, coal roof rock mechanic characteristics and hydrogeological condition analyses, focused on ultra-thin weathered bedrock and loose beds aquifer (aquifuge) rock characteristics and water degradation of strongly weathered rock impacts on working face winning. On the basis of theoretic computation, field measured data and mining practices, focused on impacts from physical properties of weathered bedrock and aquifer (aquifuge) and strongly weathered rock water degradation on heights of caving zone, water conducted zone, then designed rational safety pillar. The prac-tices have demonstrated that strongly weathered rock’s weak, water degradation and weathering properties can lower down heights of caving zone and water conducted zone, thus in favor of working face safe winning.

  5. Long-term stability of arch support and bedrock of Daning River Bridge%大宁河特大拱桥拱座-基岩长期稳定性研究

    Institute of Scientific and Technical Information of China (English)

    杨建平; 陈卫忠; 于洪丹; 谭贤君

    2011-01-01

    The arch support at Wushan end of Daning River Bridge is constructed on weathered solution-collapse breccias,which is soft and prone to creep.Evaluation of long-term stability of arch support and breccias is of great importance for the security of service of Daning River Bridge.Based on the laboratory creep test results of weathered solution-collapse breccias,a creep constitutive model is established and the parameters are proposed.Using the creep model,the long-term evolution of stress and deformation of the arch support and breccias is analyzed by means of the 3D finite element method(FEM).The openings and shear stress between the contact surface of arch support and breccias are studied.Numerical results show that:(1) the creep of breccias can cause local tensile stress concentration on thrust resistance piles;(2) the arch support and bedrock show compatible deformation during long-term creep,and the opening of the contact surface is very small.In addition,the shear stress in most part of the contact surface is less than 0.1 MPa.This study may be helpful for the design of arch support and long-term maintenance of the slope.%大宁河特大拱桥巫山端拱座建造在弱风化溶崩角砾岩基岩上,拱座–基岩的长期稳定性是桥梁安全运营的关键。依据弱风化溶崩角砾岩蠕变试验得到的幂函数形式蠕变方程,建立了三维拱座–基岩接触面有限元模型,通过数值仿真研究了桥梁长期运营过程中弱风化溶崩角砾岩基岩的应力特征、变形特征、拱座的应力分布变化规律、拱座–基岩接触面剪切应力分布及张开度变化等特性,研究成果表明:①基岩长期蠕变导致应力调整,拱座抗推桩会出现拉应力集中;②长期蠕变过程中拱座–基岩协调变形,接触面张开度很小,拱座–基岩接触面上顺桥向剪切应力也较小。研究成

  6. Final disposal of high-level nuclear waste in very deep boreholes. An evaluation based on recent research of bedrock conditions at great depths; Slutfoervaring av hoegaktivt kaernavfall i djupa borrhaal. En utvaerdering baserad paa senare aars forskning om berggrunden paa stora djup

    Energy Technology Data Exchange (ETDEWEB)

    Aahaell, Karl-Inge [Karlstad Univ. (Sweden)

    2007-01-15

    This report evaluates the feasibility of very deep borehole disposal of high-level nuclear waste, e.g., spent nuclear fuel, in the light of recent technological developments and research on the characteristics of bedrock at extreme depths. The evaluation finds that new knowledge in the field of hydrogeology and technical advances in drilling technology have advanced the possibility of using very deep boreholes (3-5 km) for disposal of the Swedish nuclear waste. Decisive factors are (1) that the repository can be located in stable bedrock at a level where the groundwater is isolated from the biosphere, and (2) that the waste can be deposited and the boreholes permanently sealed without causing long-term disturbances in the density-stratification of the groundwater that surrounds the repository. Very deep borehole disposal might offer important advantage compared to the relatively more shallow KBS approach that is presently planned to be used by the Swedish nuclear industry in Sweden, in that it has the potential of being more robust. The reason for this is that very deep borehole disposal appears to permit emplacement of the waste at depths where the entire repository zone would be surrounded by stable, density-stratified groundwater having no contact with the surface, whereas a KBS-3 repository would be surrounded by upwardly mobile groundwater. This hydro-geological difference is a major safety factor, which is particularly apparent in all scenarios that envisage leakage of radioactive substances. Another advantage of a repository at a depth of 3 to 5 km is that it is less vulnerable to impacts from expected events (e.g., changes in groundwater conditions during future ice ages) as well as undesired events (e.g. such as terrorist actions, technical malfunction and major local earthquakes). Decisive for the feasibility of a repository based on the very deep borehole concept is, however, the ability to emplace the waste without failures. In order to achieve this

  7. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  8. Levels of potassium, uranium, thorium and rate of radiogenic heat production in the bedrock adjacent to Camamu and Almada sedimentary basins, Bahia, Brazil; Teores de potassio, uranio, torio e taxa de producao de calor radiogenico no embasamento adjacente as bacias sedimentares de Camamu e Almada, Bahia, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Sapucaia, Najara Santos; Barbosa, Johildo Salomao Figueiredo [Instituto de Geociencias, Universidade Federal da Bahia, Salvador, BA (Brazil); Argollo, Roberto Max de, E-mail: nss@cpgg.ufba.br, E-mail: johildo@cpgg.ufba.br, E-mail: robmax@ufba.br [Laboratorio de Fisica Nuclear Aplicada, Instituto de Fisica, Universidade Federal da Bahia, Salvador, BA (Brazil)

    2005-10-15

    The bedrock adjacent to Camamu and Almada sedimentary basins is characterized mainly by rocks of granulite and amphibolite facies, with archaean and paleoproterozoic ages, which belong to orogen Itabuna-Salvador-Curaca. The units in major proportion in this context are the metatonalites associated with basic and metamonzonites belonging to Itabuna belt. In smaller area occur the Teolandia granite and the Moenda granodiorite associated with the Ipiau band amphibolites, the charnockites and charnoenderbites of Jequie bloc, the neoproterozoic sienites and the mafic dikes. The K, U and Th contents of the rocks vary from 0,02 to 6,33% for K, from < 0,2 to 9,10 ppm for U and from < 0,4 to 64,38 ppm for Th. These contents are higher in the charnockites, Moenda granodiorite, Teolandia granite and sienites, intermediate in the metatonalites and metamonzonites and lower in the basic granulites. The heat production rates are higher in the lithologies where K, U and Th are also higher, varying from 0,58 to 5,57 {mu}W m{sup -3}. The coverage areas of such lithologies are, however, small compared with that of the metatonalitic granulites, metamonzonitic granulites and sienites where the rates vary from 0,10 to 1,44 {mu}W m{sup -3}, 0,23 to 5,55 {mu}W m{sup -3} and 0,60 to 2,24 {mu}W m{sup -3}, respectively. In this case, the heat production rates vary from 0,10 to 1,44 {mu}W m{sup -3}. The basic granulites have the smaller rates, from 0,06 to 0,36 {mu}W m-3. The observation of the lithologies in the margins of the two basins suggest that, in the bedrock under the younger sediments, may predominate the metatonalites, followed by the metamonzonites, with some significant participation of sienites in the Almada basin. In those lithologies, the volumetric heat production rates, with one standard deviation range, are 0,41 +- 0,30 {mu}W m{sup -3} for metatonalites, 0,71 +- 0,57 {mu}W m{sup -3} for metamonzonites and 1,20 +- 0,51 {mu}W m{sup -3} for sienites. (author)

  9. Final disposal of high-level radioactive waste in deep boreholes. An evaluation based on recent research on the bedrock at great depths; Slutfoervaring av hoegaktivt kaernavfall i djupa borrhaal. En utvaerdering baserad paa senare aars forskning om berggrunden paa stora djup

    Energy Technology Data Exchange (ETDEWEB)

    Aahaell, Karl-Inge [Karlstad Univ. (Sweden)

    2006-05-15

    New knowledge in hydrogeology and boring technology have opened the possibility to use deep boreholes as a repository for the Swedish high-level radioactive wastes. The determining property is that the repository can be housed in the stable bedrock at levels where the ground water has no contact with the biosphere and disposal and sealing can take place without disturbing the ground water stratification outside the disposal area. An advantage compared to a shallow repository of KBS-3 type, that is now being planned in Sweden, is that a borehole repository is likely to be technologically more robust, since the concept 'deep boreholes' seems to admit such a deep disposal that the entire disposal area would be surrounded by stable density-layered ground water, while a KBS-3 repository would be surrounded by moving ground water in contact with level close to the surface. This hydrological difference is of great importance for the safety in scenarios with leaching of radioactive substances. A deep repository is also less vulnerable for effects from natural events such as glaciation and earthquakes as well as from technological mishaps and terrorist actions. A crucial factor is, however, that the radioactive waste can be disposed of, in a secure way, at the intended depth, which will require new research and technology development.

  10. Delineation of areas having elevated electrical conductivity, orientation and characterization of bedrock fractures, and occurrence of groundwater discharge to surface water at the U.S. Environmental Protection Agency Barite Hill/Nevada Goldfields Superfund site near McCormick, South Carolina

    Science.gov (United States)

    Chapman, Melinda J.; Huffman, Brad A.; McSwain, Kristen Bukowski

    2015-07-16

    During October 2012 through March 2013, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (EPA) Region 4, Superfund Section, conducted borehole geophysical logging, surface geophysical surveys, and water-quality profiling in selected wells and areas to characterize or delineate the extent of elevated subsurface electrical conductivity at the EPA Barite Hill/Nevada Goldfields Superfund site near McCormick, South Carolina. Elevated electrical conductivity measured at the site may be related to native rock materials, waste rock disposal areas used in past operations, and (or) groundwater having elevated dissolved solids (primarily metals and major ions) related to waste migration. Five shallow screened wells and four open-borehole bedrock wells were logged by using a suite of borehole tools, and downhole water-quality profiles were recorded in two additional wells. Well depths ranged from about 26 to 300 feet below land surface. Surface geophysical surveys based on frequency-domain electromagnetic and distributed temperature sensing (DTS) techniques were used to identify areas of elevated electrical conductivity (Earth materials and groundwater) and potential high dissolved solids in groundwater and surface water on land and in areas along the northern unnamed tributary at the site.

  11. Dendritic Cell

    OpenAIRE

    Sevda Söker

    2005-01-01

    Dendritic cells, a member of family of antigen presenting cells, are most effective cells in the primary immune response. Dendritic cells originated from dendron, in mean of tree in the Greek, because of their long and elaborate cytoplasmic branching processes. Dendritic cells constitute approximately 0.1 to 1 percent of the blood’s mononuclear cell. Dendritic cells are widely distributed, and specialized for antigen capture and T cell stimulation. In this article, structures and functions of...

  12. Bedrock Geologic Map of the Greater Lefkosia Area, Cyprus

    Science.gov (United States)

    Harrison, Richard W.; Newell, Wayne; Panayides, Ioannis; Stone, Byron; Tsiolakis, Efthymios; Necdet, Mehmet; Batihanli, Hilmi; Ozhur, Ayse; Lord, Alan; Berksoy, Okan; Zomeni, Zomenia; Schindler, J. Stephen

    2008-01-01

    The island of Cyprus has a long historical record of earthquakes that have damaged pre-Roman to modern human settlements. Because the recurrent damaging earthquakes can have a significant economic and social impact on Cyprus, this project was initiated to develop a seismic-hazard assessment for a roughly 400 square kilometer area centered on Cyprus' capital and largest city, whose European name is Nicosia and whose local name is Lefkosia. In addition, geologic and seismotectonic evaluations for the project extended beyond the perimeter of the geologic map. Additional structural, stratigraphic, and paleontological data were collected island-wide as well as data from literature research throughout the eastern Mediterranean region, in order to accurately place the geology and seismic hazards of the Lefkosia area in a regional tectonic framework.

  13. Bedrock geology of the northern Columbia Plateau and adjacent areas

    Science.gov (United States)

    Swanson, D. A.; Wright, T. L.

    1978-01-01

    The Columbia Plateau is surrounded by a complex assemblage of highly deformed Precambrian to lower Tertiary continental and oceanic rocks that reflects numerous episodes of continental accretion. The plateau itself is comprised of the Columbia River basalt group formed between about 16.5 x 1 million years B.P. and 6 x 1 million years B.P. Eruptions were infrequent between about 14 and 6 x 1 million years B.P., allowing time for erosion and deformation between successive outpourings. The present-day courses of much of the Snake River, and parts of the Columbia River, across the plateau date from this time. Basalt produced during this waning activity is more heterogeneous chemically and isotopically than older flows, reflecting its prolonged period of volcanism.

  14. Significant differences in late Quaternary bedrock erosion and transport

    DEFF Research Database (Denmark)

    Andrews, John; Bjørk, Anders Anker; Eberl, Dennis;

    2015-01-01

    We use quantitative X-ray diffraction to determine the mineralogy of late Quaternary marine sediments from the West and East Greenland shelves offshore from early Tertiary basalt outcrops. Despite the similar basalt outcrop area (60 000–70 000 km2), there are significant differences between East ...

  15. Seasonal sediment dynamics shape temperate bedrock reef communities

    Science.gov (United States)

    Figurski, Jared D.; Freiwald, Jan; Lonhart, Steve I.; Storlazzi, Curt

    2016-01-01

    Mobilized seafloor sediment can impact benthic reef communities through burial, scour, and turbidity. These processes are ubiquitous in coastal oceans and, through their influence on the survival, fitness, and interactions of species, can alter the structure and function of benthic communities. In northern Monterey Bay, California, USA, as much as 30% of the seafloor is buried or exposed seasonally, making this an ideal location to test how subtidal temperate rocky reef communities vary in the presence and absence of chronic sediment-based disturbances. Designated dynamic plots were naturally inundated by sediment in summer (50 to 100% cover) and swept clean in winter, whereas designated stable plots remained free of sediment during our study. Multivariate analyses indicated significant differences in the structure of sessile and mobile communities between dynamic and stable reef habitats. For sessile species, community structure in disturbed plots was less variable in space and time than in stable plots due to the maintenance of an early successional state. In contrast, community structure of mobile species varied more in disturbed plots than in stable plots, reflecting how mobile species distribute in response to sediment dynamics. Some species were found only in these disturbed areas, suggesting that the spatial mosaic of disturbance could increase regional diversity. We discuss how the relative ability of species to tolerate disturbance at different life history stages and their ability to colonize habitat translate into community-level differences among habitats, and how this response varies between mobile and sessile communities.

  16. DNAPL Dissolution in Bedrock Fractures And Fracture Networks

    Science.gov (United States)

    2011-06-01

    concentrations using the Pendant Drop Method (6, 92), then regressing a polynomial expression to the data. Interfacial tension results are shown in Figure...tension as a function of SDBS concentration in water. The polynomial regressed to the data was used to compute the derivative in Equation 5-5...dissolution and detoxification of dense nonaqueous phase liquid contaminants. Environ. Sci. Technol. 2009, 43, 870-877. (29) Sleep , B.E

  17. Microstructure, porosity and mineralogy around fractures in Olkiluoto bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Kuva, J. (ed.); Myllys, M.; Timonen, J. [Jyvaeskylae Univ. (Finland); Kelokaski, M.; Ikonen, J.; Siitari-Kauppi, M. [Helsinki Univ. (Finland); Lindberg, A. [Geological Survey of Finland, Espoo (Finland); Aaltonen, I.

    2012-01-15

    3D distributions of minerals and porosities were determined for samples that included waterconducting fractures. The analysis of these samples was performed using conventional petrography methods, electron microscopy, C-14-PMMA porosity analysis and X-ray tomography. While X-ray tomography proved to be a very useful method when determining the inner structure of the samples, combining tomography results with those obtained by other methods turned out to be difficult without very careful sample preparation design. It seems that the properties of rock around a water-conducting fracture depend on so many uncorrelated factors that no clear pattern emerged even for rock samples with a given type of fracture. We can conclude, however, that a combination of different analysis methods can be useful and used to infer novel structural information about alteration zones adjacent to fracture surfaces. (orig.)

  18. OSL-thermochronometry using bedrock quartz: A note of caution

    NARCIS (Netherlands)

    Guralnik, B.; Ankjærgaard, C.; Jain, M.; Murray, A.S.; Müller, A.; Walle, M.; Lowick, S.E.; Preusser, F.; Rhodes, E.J.; Wu, T.S.; Mathew, G.; Herman, F.

    2015-01-01

    Optically stimulated luminescence (OSL) thermochronometry is an emerging application, whose capability to record sub-Million-year thermal histories is of increasing interest to a growing number of subdisciplines of Quaternary research. However, several recent studies have encountered difficulties bo

  19. Reinjection Tests in bedrock Geothermal Reservoir of Tianjin

    Institute of Scientific and Technical Information of China (English)

    朱家玲; 王坤

    2004-01-01

    By the end of 2002, there are about 219 production wells (including 12 reinjection wells) in Tianjin. The annual production rate is 1.5×107 m3 and the reinjection rate is 1.66×106 m3. The main side effect anticipated from reinjection is the cooling of the reservoir. It is necessary to estimate the thermal breakthrough time in different distances between injection-production wells. This paper describes the 2-D mass and heat transfer in the heterogeneous fractured rocks. The equations that arise for each grid block must be linearized. The main reinjection model is simulated by a program of the TOUGH2 to analyze the change of the temperature field and predict the pressure and heat break-through. The tracer test is very important for understanding the transportation pathway and transport channel/space in the doublet system, and estimating the possible cooling resulted from the injection processes.

  20. Values: The Bedrock of the Military Profession. A Selective Bibliography

    Science.gov (United States)

    1986-06-01

    conflicts of allegiance to his mission and his soldiers, and a psychological thriller that introspectively examines the effects of shouldering the...Church, VA: Center for Advanced Studies & Analyses, Westinghouse Electric Corp., 1973. 69 p. E 182 .W3. Primarily a literature survey, this study uses

  1. Glacial flutings in bedrock, an observation in East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1978-01-01

    Large scale glacial flutings cover an area of 4 x 1.5 km on the northern shore of Harefjord in the interior Scoresby Sund fjord complex. The flutings are modelled in coarse sandstone and conglomerates, a few small features are probably composed of till. The ridges measure up to' 2000 m in length...... and 5 m in height and occur between 50 and 250 m above sea level inthe gently sloping lowland area adjacent to the fjord. They were probably formed beneath the lateral part of the former Harefjord-Glacier which receded rapidly in the fjord and exposed the area at c. 7500 years BP. Large scale glacial...... flutings have not been recorded before in Greenland, but seem to be of common occurrence in parts of North America. They have probably been formed near the margin of actively moving glaciers, and secondary flow in the basal ice may have played an important role...

  2. OSL-thermochronometry using bedrock quartz: a note of caution

    DEFF Research Database (Denmark)

    Guralnik, B.; Ankjærgaard, Christina; Jain, Mayank;

    2015-01-01

    , and may hamper successful OSL dating. Furthermore, even when the desirable signal is present, its concentration might be indistinguishable from its environmental steady-state prediction, thus preventing its conversion to a cooling or heating history. We explore the saturation properties and the thermal...

  3. Bedrock aquifers of eastern San Juan County, Utah

    Science.gov (United States)

    Avery, Charles

    1986-01-01

    This study is one of a series of studies appraising the waterbearing properties of the Navajo Sandstone and associated formations in southern Utah.  The study area is about 4,600 square miles, extending from the Utah-Arizona State line northward to the San Juan-Grand County line and westward from the Utah-Colorado State line to the longitude of about 109°50'.Some of the water-yielding formations are grouped into aquifer systems. The C aquifer is comprised of the DeChelly Sandstone Member of the Cutler Formation.  The P aquifer is comprised of the Cedar Mesa Member of the Cutler Formation and the undifferentiated Cutler Formation. The N aquifer is comprised of the sedimentary section that includes the Wingate Sandstone, Kayenta Formation, Navajo Sandstone, Carmel Formation, and Entrada sandstone.  The M aquifer is comprised of the Bluff Sandstone Member and other sandstone units of the Morrison Formation.  The D aquifer is comprised of the Burro Canyon Formation and Dakota Sandstone.  Discharge from the ground-water reservoir to the San Juan River between gaging stations at Four Corners and Mexican Hat is about 66 cubic feet per second.The N aquifer is the main aquifer in the study area. Recharge by infiltration of precipitation is estimated to be 25,000 acre-feet per year.  A major ground-water divide exists under the broad area east of Monticello.  The thickness of the N aquifer, where the sedimentary section is fully preserved and saturated, generally is 750 to 1,250 feet.   Hydraulic conductivity values obtained from aquifer tests range from 0.02 to 0.34 foot per day.  The total volume of water in transient storage is about 11 million acre-feet. Well discharge somewhat exceeded 2,340 acre-feet during 1981.  Discharge to the San Juan River from the N aquifer is estimated to be 6.9 cubic feet per second. Water quality ranges from a calcium bicarbonate to sodium chloride type water

  4. Evaluation of percolation rate of bedrock aquifer in coastal area

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Hwan; Jung, Hae Ryong; Park, Joo Wan; Yoon, Jeong Hyoun; Cheong, Jae Yeol [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of); Park, Sun Ju [NEXGEO Co. Ltd, Seoul (Korea, Republic of); Jun, Seong Chun [GeoGreen21 Co. Ltd, Seoul (Korea, Republic of)

    2016-03-15

    Estimation of groundwater hydrologic cycle pattern is one of the most critical issues in sustainable management of groundwater resources in coastal area. This study estimated groundwater percolation by using the water balance methodology and hydrogeological characteristics of land use and soil. Evapotranspiration was computed by using the Thornthwaite method, and surface runoff was determined by using the SCS-CN technique. Groundwater storage change was obtained as 229 mm/a (17.8% of the average annual rainfall, 1286 mm/a), with 693 mm/a (60.1%) of evapotranspiration and 124 mm/a (9.6%) of surface runoff. Rainfall and groundwater storage change was highly correlated, comparing with the relationships between rainfall and evapotranspiration, and between rainfall and surface runoff. This result indicates that groundwater storage change responds more sensitively to precipitation than evapotranspiration and surface runoff.

  5. Galvanic Cells

    Science.gov (United States)

    Young, I. G.

    1973-01-01

    Many standard physical chemistry textbooks contain ambiguities which lead to confusion about standard electrode potentials, calculating cell voltages, and writing reactions for galvanic cells. This article shows how standard electrode potentials can be used to calculate cell voltages and deduce cell reactions. (Author/RH)

  6. Cell Biochips

    Science.gov (United States)

    Pioufle, B. Le; Picollet-D'Hahan, N.

    A cell biochip is a microsystem, equipped with electronic and microfluidic functions, designed to manipulate or analyse living cells. The first publications in this emerging area of research appeared toward the end of the 1980s. In 1989 Washizu described a biochip designed to fuse two cells by electropermeabilisation of the cytoplasmic membrane [1]. Research centers have devised a whole range of cell chip structures, for simultaneous or sequential analysis of single cells, cell groups, or cell tissues reconstituted on the chip. The cells are arranged in a square array on a parallel cell chip for parallel analysis, while they are examined and processed one by one in a microchannel in the case of a series cell chip. In contrast to these biochips for high-throughput analysis of a large number of cells, single-cell chips focus on the analysis of a single isolated cell. As in DNA microarrays, where a large number of oligonucleotides are ordered in a matrix array, parallel cell chips order living cells in a similar way. At each point of the array, the cells can be isolated, provided that the cell type allows this, e.g., blood cells, or cultivated in groups (most adhesion cells can only survive in groups). The aim is to allow massively parallel analysis or processing. Le Pioufle et al. describe a microdevice for the culture of single cells or small groups of cells in a micropit array [2]. Each pit is equipped to stimulate the cell or group of cells either electrically or fluidically. Among the applications envisaged are gene transfer, cell sorting, and screening in pharmacology. A complementary approach, combining the DNA microarray and cell biochip ideas, has been put forward by Bailey et al. [3]. Genes previously arrayed on the chip transfect the cultured cells on the substrate depending on their position in the array (see Fig. 19.1). This way of achieving differential lipofection on a chip was then taken up again by Yoshikawa et al. [4] with primary cells, more

  7. Stem cells in cell transplantation.

    Science.gov (United States)

    Sanmartin, Agneta; English, Denis; Sanberg, Paul R

    2006-12-01

    This commentary documents the increased number of stem cell-related research reports recently published in the cell transplantation field in the journal Cell Transplantation. The journal covers a wide range of issues in cell-based therapy and regenerative medicine and is attracting clinical and preclinical articles from around the world. It thereby complements and extends the basic coverage of stem cell physiology reported in Stem Cells and Development. Sections in Cell Transplantation cover neuroscience, diabetes, hepatocytes, bone, muscle, cartilage, skin, vessels, and other tissues, as well as tissue engineering that employs novel methods with stem cells. Clearly, the continued use of biomedical engineering will depend heavily on stem cells, and these two journals are well positioned to provide comprehensive coverage of these developments.

  8. Engineering cell-cell signaling.

    Science.gov (United States)

    Blagovic, Katarina; Gong, Emily S; Milano, Daniel F; Natividad, Robert J; Asthagiri, Anand R

    2013-10-01

    Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cells (cell surface engineering and synthetic gene circuits) to modulate juxtacrine cell-cell signaling. In addition, significant progress has been made in elucidating design rules and strategies to modulate juxtacrine signaling on the basis of quantitative, engineering analysis of the mechanical and regulatory role of juxtacrine signals in the context of other cues and physical constraints in the microenvironment. These advances in engineering juxtacrine signaling lay a strong foundation for an integrative approach to utilize synthetic cells, advanced 'chassis' and predictive modeling to engineer the form and function of living tissues.

  9. Cell Motility

    CERN Document Server

    Lenz, Peter

    2008-01-01

    Cell motility is a fascinating example of cell behavior which is fundamentally important to a number of biological and pathological processes. It is based on a complex self-organized mechano-chemical machine consisting of cytoskeletal filaments and molecular motors. In general, the cytoskeleton is responsible for the movement of the entire cell and for movements within the cell. The main challenge in the field of cell motility is to develop a complete physical description on how and why cells move. For this purpose new ways of modeling the properties of biological cells have to be found. This long term goal can only be achieved if new experimental techniques are developed to extract physical information from these living systems and if theoretical models are found which bridge the gap between molecular and mesoscopic length scales. Cell Motility gives an authoritative overview of the fundamental biological facts, theoretical models, and current experimental developments in this fascinating area.

  10. Photovoltaic Cells

    Directory of Open Access Journals (Sweden)

    Karolis Kiela

    2012-04-01

    Full Text Available The article deals with an overview of photovoltaic cells that are currently manufactured and those being developed, including one or several p-n junction, organic and dye-sensitized cells using quantum dots. The paper describes the advantages and disadvantages of various photovoltaic cells, identifies the main parameters, explains the main reasons for the losses that may occur in photovoltaic cells and looks at the ways to minimize them.Article in Lithuanian

  11. Engineering Cell-Cell Signaling

    OpenAIRE

    Blagovic, Katarina; Gong, Emily S.; Milano, Daniel F.; Natividad, Robert J.; Asthagiri, Anand R

    2013-01-01

    Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cel...

  12. Stem Cells

    Directory of Open Access Journals (Sweden)

    Madhukar Thakur

    2015-02-01

    Full Text Available Objective: The objective of this presentation is to create awareness of stem cell applications in the ISORBE community and to foster a strategy of how the ISORBE community can disseminate information and promote the use of radiolabeled stem cells in biomedical applications. Methods: The continued excitement in Stem Cells, in many branches of basic and applied biomedical science, stems from the remarkable ability of stem cells to divide and develop into different types of cells in the body. Often called as Magic Seeds, stem cells are produced in bone marrow and circulate in blood, albeit at a relatively low concentration. These virtues together with the ability of stem cells to grow in tissue culture have paved the way for their applications to generate new and healthy tissues and to replace diseased or injured human organs. Although possibilities of stem cell applications are many, much remains yet to be understood of these remarkable magic seeds. Conclusion: This presentation shall briefly cover the origin of stem cells, the pros and cons of their growth and division, their potential application, and shall outline some examples of the contributions of radiolabeled stem cells, in this rapidly growing branch of biomedical science

  13. Types of Stem Cells

    Science.gov (United States)

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  14. Fuel Cells

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Fuel cells have been the subject of intense research and development efforts for the past decades. Even so, the technology has not had its commercial breakthrough yet. This entry gives an overview of the technological challenges and status of fuel cells and discusses the most promising applications...... of the different types of fuel cells. Finally, their role in a future energy supply with a large share of fluctuating sustainable power sources, e.g., solar or wind, is surveyed....

  15. Stem cells.

    Science.gov (United States)

    Redi, Carlo Alberto; Monti, Manuela; Merico, Valeria; Neri, Tui; Zanoni, Mario; Zuccotti, Maurizio; Garagna, Silvia

    2007-01-01

    The application of stem cells to regenerative medicine is one of the actual hot topics in biomedicine. This research could help the cure of a number of diseases that are affecting a large share of the population. Some good results in cell replacement have already been obtained (infarcted heart, diabetes, Parkinson disease), apart from those of more traditional applications like severe burns and blood tumors. We are now facing crucial questions in stem cell biology. One of the key questions is how a cell begins to proliferate or differentiate. Genome reprogramming, both following nuclear transfer and cytoplast action, will likely highlight some of the molecular mechanisms of cell differentiation and dedifferentiation. In turn, these clues should be useful to the production of populations of reprogrammed cells that could develop into tissues or, in the future, into proper organs. We will overview what stem cells are, what roles they play in normal developmental processes and how stem cells could have the potential to treat diseases.

  16. Fuel Cells

    Science.gov (United States)

    Hawkins, M. D.

    1973-01-01

    Discusses the theories, construction, operation, types, and advantages of fuel cells developed by the American space programs. Indicates that the cell is an ideal small-scale power source characterized by its compactness, high efficiency, reliability, and freedom from polluting fumes. (CC)

  17. Stem Cells

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2004-01-01

    '. This paper is about tech-noscience, and about the proliferation of connections and interdependencies created by it.More specifically, the paper is about stem cells. Biotechnology in general has the power to capture the imagination. Within the field of biotechnology nothing seems more provocative...... and tantalizing than stem cells, in research, in medicine, or as products....

  18. Sickle cell anemia

    Science.gov (United States)

    ... Anemia - sickle cell; Hemoglobin SS disease (Hb SS); Sickle cell disease Images Red blood cells, sickle cell Red blood cells, normal Red blood ... multiple sickle cells Red blood cells, sickle cells Red blood cells, sickle and ... Heeney MM, Ware RE. Sickle cell disease. In: Orkin SH, Fisher DE, Ginsburg D, Look ...

  19. Characteristics of Non2uniformity and Vulnerability of Aquifers to Dewatering of Bedrock Fissure Water in the Hilly Area of the Taihang Mountains Piedmont%太行山前丘陵区基岩裂隙水赋存的非均一性和易疏干性特征

    Institute of Scientific and Technical Information of China (English)

    张光辉; 严明疆; 刘春华; 冯慧敏; 王金哲

    2013-01-01

    In terms of the issues of sustainable utilization of groundw ater in the hil y area of the Taihang mountains piedmont, the characteristics of non2uniformity and vulnerability of the aquifers to dew atering in the area w ere investigated based on the quan2 titative comparison analysis of the pumping and recovery test data from the deep bedrock fissure groundwat er w ells. The re2 search results showed t hat the spatial non2uniformity exists not only in the groundwater storage betw een different w ells, but al2 so in different dept hs of t he same well. For the pumping t ime less than 70 minutes, t he drawdow n of groundwater level in the well ZKs23 was larger than that in t he well Zks22. However, after 70 minutes of pumping, the draw down of groundw ater level in the w el ZKs22 w as larger than that in the w ell ZKs23, and the drawdow n difference betw een t he tw o w el s increased gradually wit h the increasing pumping time. These results indicated that the upper aquifer of w el ZKs22 has more w ater than the low er aquifer of well ZKs22, while the upper aquifer of w ell ZKs23 has less w ater than the lower aquifer of w el ZKs23. T he aquifer systems in different w el s had different vulnerability of groundwater to dewatering. With the increasing of pumping time, the maximum draw down and the time for recovery of groundwater level in the w ell ZKs22 increased, but the groundw ater level can be ful y restored to the initial level. H ow ever, the groundw ater level cannot recover to the initial level in the w el ZKs23, and the difference between the recovered groundw ater level and initial level increased as well, but the recovery t ime of groundwater level to a stable level w ere similar for different pumping t ests. Therefore, the reasonable design and layout of w el s is important to prevent the aquifers to dewatering in t he hilly area.%  针对太行山东簏丘陵区地下水能否可持续开发利用问题,基于探采结合的大量深井抽水及

  20. Bi-Cell Unit for Fuel Cell.

    Science.gov (United States)

    The patent concerns a bi-cell unit for a fuel cell . The bi-cell unit is comprised of two electrode packs. Each of the electrode packs includes an...invention relates in general to a bi-cell unit for a fuel cell and in particular, to a bi-cell unit for a hydrazine-air fuel cell .

  1. Cell, cell, cell: fuel cell applications moving ahead

    Energy Technology Data Exchange (ETDEWEB)

    Ross, E.

    2001-11-01

    Developments in fuel cell technology within the last decade, such as the targeting by major automakers of non-polluting fuel cells as an alternative to the internal combustion engine, are reviewed. For example, Ballard Power Systems of Vancouver is the exclusive supplier to both DaimlerCrysler and the Ford Motor Company of the fuel cell stacks that produce the power in fuel cell systems. Ballard plans the commercial launch of transit bus engines in 2002 and automotive products between 2003 and 2005. The company also sees huge opportunities for fuel cells in stationary and portable power applications. At the same time, the Calgary-based fuel cell division of Energy Ventures Inc. is developing a direct methanol fuel cell that eliminates the intermediate step of 'reforming' methanol into hydrogen that is required in the Ballard process. Energy Ventures targets small niche markets such as small utility vehicles for its direct methanol fuel cell. A completely self-contained fuel cell of this type is expected to be ready in 2002. Solid oxide fuel cells for off-grid remote power units as well as for home heat and power is yet another field of development that will be particularly attractive to operations in remote areas where reliable grid electricity is expensive and hard to obtain. A prototype 2.3 kW residential power system using natural gas was made available by Global Thermoelectric Inc in June 2001; field testing is planned for 2002, with commercial production in late 2003 or 2004. The Calgary-based Snow Leopard Resources Inc plans to use pure hydrogen sulphide obtained from sour natural gas as a hydrogen source. The prime focus of Snow Leopard is on gas plants looking for ways to increase their efficiency, obtain carbon dioxide credits and generate electricity on site. This type of fuel cell also could be of interest to companies with shut-in sour gas since these companies could use the stationary fuel cell system to generate electricity.

  2. Learn About Stem Cells

    Science.gov (United States)

    ... Patient Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... original cell’s DNA, cytoplasm and cell membrane. About stem cells Stem cells are the foundation of development in ...

  3. Fuel cells

    Directory of Open Access Journals (Sweden)

    D. N. Srivastava

    1962-05-01

    Full Text Available The current state of development of fuel cells as potential power sources is reviewed. Applications in special fields with particular reference to military requirements are pointed out.

  4. Electrochemical cell

    Science.gov (United States)

    Nagy, Zoltan; Yonco, Robert M.; You, Hoydoo; Melendres, Carlos A.

    1992-01-01

    An electrochemical cell has a layer-type or sandwich configuration with a Teflon center section that houses working, reference and counter electrodes and defines a relatively narrow electrolyte cavity. The center section is surrounded on both sides with thin Teflon membranes. The membranes are pressed in place by a pair of Teflon inner frames which are in turn supported by a pair of outer metal frames. The pair of inner and outer frames are provided with corresponding, appropriately shaped slits that are in plane generally transverse to the plane of the working electrode and permit X-ray beams to enter and exit the cell through the Teflon membranes that cover the slits so that the interface between the working electrode and the electrolyte within the cell may be analyzed by transmission geometry. In one embodiment, the center section consists of two parts, one on top of the other. Alternatively, the center section of the electrochemical cell may consist of two intersliding pieces or may be made of a single piece of Teflon sheet material. The electrolyte cavity is shaped so that the electrochemical cell can be rotated 90.degree. in either direction while maintaining the working and counter electrodes submerged in the electrolyte.

  5. Fuel cells:

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2013-01-01

    A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil and nucl......A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil...

  6. CellTracks cell analysis system for rare cell detection

    NARCIS (Netherlands)

    Kagan, Michael T.; Trainer, Michael N.; Bendele, Teresa; Rao, Chandra; Horton, Allen; Tibbe, Arjan G.; Greve, Jan; Terstappen, Leon W.M.M.

    2002-01-01

    The CellTracks system is a Compact Disk-based cell analyzer that, similar to flow cytometry, differentiates cells that are aligned while passing through focused laser beams. In CellTracks, only immuno-magnetically labeled cells are aligned and remain in position for further analysis. This feature is

  7. Sickle Cell Anemia

    Science.gov (United States)

    Sickle cell anemia is a disease in which your body produces abnormally shaped red blood cells. The cells ... red blood cells. This leads to anemia. The sickle cells also get stuck in blood vessels, blocking blood ...

  8. Sickle Cell Disease

    Science.gov (United States)

    ... sickle cell disease?Sickle cell disease, also called sickle cell anemia, is a hereditary condition (which means it runs ... disease, hemoglobin SS disease, hemoglobin synthesis, hemoglobinopathies, ... cell anemia, sickle cell crisis, vaso-occlusive crisis Family Health, ...

  9. Stem Cell Information: Glossary

    Science.gov (United States)

    ... bone, cartilage, stromal cells that support blood formation, fat, and fibrous tissue. Cell-based therapies —Treatment in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cells or ...

  10. Squamous Cell Carcinoma

    Science.gov (United States)

    ... Kids’ zone Video library Find a dermatologist Squamous cell carcinoma Overview Squamous cell carcinoma: This man's skin ... a squamous cell carcinoma on his face. Squamous cell carcinoma: Overview Squamous cell carcinoma (SCC) is a ...

  11. Electrochemical Cell

    DEFF Research Database (Denmark)

    1999-01-01

    The invention relates to a rechargeable electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode in which the positive electrode structure comprises a lithium cobalt manganese oxide of the composition Li¿2?Co¿y?Mn¿2-y?O¿4? where 0

  12. Potent Cells

    Science.gov (United States)

    Liu, Dennis

    2007-01-01

    It seems hard to believe that Dolly the cloned sheep was born 10 years ago, kindling furious arguments over the prospects and ethics of cloning a human. Today, the controversy over cloning is entwined, often confused, with concerns over the use of human embryonic stem cells. Most people are unclear what cloning is, and they know even less when it…

  13. Photovoltaic cell

    Science.gov (United States)

    Gordon, Roy G.; Kurtz, Sarah

    1984-11-27

    In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

  14. Fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, Hirofumi.

    1989-05-22

    This invention aims to maintain a long-term operation with stable cell output characteristics by uniformly supplying an electrolyte from the reserver to the matrix layer over the entire matrix layer, and further to prevent the excessive wetting of the catalyst layer by smoothly absorbing the volume change of the electrolyte, caused by the repeated stop/start-up of the fuel cell, within the reserver system. For this purpose, in this invention, an electrolyte transport layer, which connects with an electrolyte reservor formed at the electrode end, is partly formed between the electrode material and the catalyst layer; a catalyst layer, which faces the electrolyte transport layer, has through-holes, which connect to the matrix, dispersely distributed. The electrolyte-transport layer is a thin sheet of a hydrophilic fibers which are non-wovens of such fibers as carbon, silicon carbide, silicon nitride or inorganic oxides. 11 figs.

  15. Ghost cell lesions

    Directory of Open Access Journals (Sweden)

    E Rajesh

    2015-01-01

    Full Text Available Ghost cells have been a controversy for a long time. Ghost cell is a swollen/enlarged epithelial cell with eosnophilic cytoplasm, but without a nucleus. In routine H and E staining these cells give a shadowy appearance. Hence these cells are also called as shadow cells or translucent cells. The appearance of these cells varies from lesion to lesion involving odontogenic and nonodontogenic lesions. This article review about the origin, nature and significance of ghost cells in different neoplasms.

  16. [Inflammatory dendritic cells].

    Science.gov (United States)

    Segura, Elodie; Amigorena, Sebastian

    2014-01-01

    Dendritic cells are a rare and heterogeneous population of professional antigen-presenting cells. Several murine dendritic cell subpopulations have been identified that differ in their phenotype and functional properties. In the steady state, committed dendritic cell precursors differentiate into lymphoid organ-resident dendritic cells and migratory tissue dendritic cells. During inflammation appears an additional dendritic cell subpopulation that has been termed « inflammatory dendritic cells ». Inflammatory dendritic cells differentiate in situ from monocytes recruited to the site of inflammation. Here, we discuss how mouse inflammatory dendritic cells differ from macrophages and from other dendritic cell populations. Finally, we review recent work on human inflammatory dendritic cells.

  17. Red blood cells, sickle cell (image)

    Science.gov (United States)

    Sickle cell anemia is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). ... abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in this photomicrograph.

  18. Red blood cells, multiple sickle cells (image)

    Science.gov (United States)

    Sickle cell anemia is an inherited disorder in which abnormal hemoglobin (the red pigment inside red blood cells) is produced. The abnormal hemoglobin causes red blood cells to assume a sickle shape, like the ones seen in this photomicrograph.

  19. CellFinder: a cell data repository

    OpenAIRE

    Stachelscheid, H.; Seltmann, S.; Lekschas, F.; Fontaine, J.F.; Mah, N.; Neves, M.; Andrade-Navarro, M.A.; Leser, U; Kurtz, A.

    2014-01-01

    CellFinder (http://www.cellfinder.org) is a comprehensive one-stop resource for molecular data characterizing mammalian cells in different tissues and in different development stages. It is built from carefully selected data sets stemming from other curated databases and the biomedical literature. To date, CellFinder describes 3394 cell types and 50 951 cell lines. The database currently contains 3055 microscopic and anatomical images, 205 whole-genome expression profiles of 194 cell/tissue t...

  20. Molluscan cells in culture: primary cell cultures and cell lines

    OpenAIRE

    2013-01-01

    In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as bi...

  1. Stem Cell Basics

    Science.gov (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

  2. Basal Cell Carcinoma

    Science.gov (United States)

    ... Kids’ zone Video library Find a dermatologist Basal cell carcinoma Overview Basal cell carcinoma: This skin cancer ... that has received years of sun exposure. Basal cell carcinoma: Overview Basal cell carcinoma (BCC) is the ...

  3. Electrorefining cell evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bronson, M.C.; Thomas, R.L. (ed.)

    1989-04-14

    Operational characteristics of the LANL electrorefining cell, a modified LANL electrorefining cell, and an advanced electrorefining cell (known as the CRAC cell) were determined. Average process yields achieved were: 75% for the LANL cell, 82% for the modified LANL cell, and 86% for the CRAC cell. All product metal from the LANL and modified LANL cells was within foundry specifications. Metal from one run in the CRAC cell exceeded foundry specifications for tantalum. The LANL and modified LANL cells were simple in design and operation, but product separation was more labor intensive than with the CRAC cell. The CRAC cell was more complicated in design but remained relatively simple in operation. A decision analysis concluded that the modified LANL cell was the preferred cell. It was recommended that the modified LANL cell be implemented by the Plutonium Recovery Project at Rocky Flats and that development of the CRAC cell continue. 8 refs., 22 figs., 12 tabs.

  4. Antiparietal cell antibody test

    Science.gov (United States)

    APCA; Anti-gastric parietal cell antibody; Atrophic gastritis - anti-gastric parietal cell antibody; Gastric ulcer - anti-gastric parietal cell antibody; Pernicious anemia - anti-gastric parietal cell antibody; ...

  5. Molluscan cells in culture: primary cell cultures and cell lines.

    Science.gov (United States)

    Yoshino, T P; Bickham, U; Bayne, C J

    2013-06-01

    In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as biomonitors for environmental contaminants, as models for gene transfer technologies, and for studies of innate immunity and neoplastic disease. Despite efforts to isolate proliferative cell lines from molluscs, the snail Biomphalaria glabrata Say, 1818 embryonic (Bge) cell line is the only existing cell line originating from any molluscan species. Taking an organ systems approach, this review summarizes efforts to establish molluscan cell cultures and describes the varied applications of primary cell cultures in research. Because of the unique status of the Bge cell line, an account is presented of the establishment of this cell line, and of how these cells have contributed to our understanding of snail host-parasite interactions. Finally, we detail the difficulties commonly encountered in efforts to establish cell lines from molluscs and discuss how these difficulties might be overcome.

  6. DNA-cell conjugates

    Science.gov (United States)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  7. Molecular Mechanisms of Cell-cell Recognition

    Institute of Scientific and Technical Information of China (English)

    WANG Jia-Huai

    2004-01-01

    Cell-cell recognition is the key for multicellular organisms to survive. This recognition critically depends on protein-protein interactions from opposing cell surfaces. Recent structural investigations reveal unique features of these cell surface receptors and how they interact. These interactions are specific, but usually relatively weak, with more hydrophilic forces involved in binding. The receptors appear to have specialized ways to present their key interacting elements for ligand-binding from the cell surface. Cell-cell contacts are multivalent. A large group of cell surface molecules are engaged in interactions. Characteristic weak interactions make possible for each individual molecule pair within the group to constantly associate-dissociate-reassociate, such that the cell-cell recognition becomes a dynamic process. The immunological synapse is a good example for immune receptors to be orchestrated in performing immunological function in a collective fashion.

  8. Skin Stem Cells in Skin Cell Therapy

    Directory of Open Access Journals (Sweden)

    Mollapour Sisakht

    2015-12-01

    Full Text Available Context Preclinical and clinical research has shown that stem cell therapy is a promising therapeutic option for many diseases. This article describes skin stem cells sources and their therapeutic applications. Evidence Acquisition Compared with conventional methods, cell therapy reduces the surgical burden for patients because it is simple and less time-consuming. Skin cell therapy has been developed for variety of diseases. By isolation of the skin stem cell from the niche, in vitro expansion and transplantation of cells offers a surprising healing capacity profile. Results Stem cells located in skin cells have shown interesting properties such as plasticity, transdifferentiation, and specificity. Mesenchymal cells of the dermis, hypodermis, and other sources are currently being investigated to promote regeneration. Conclusions Because skin stem cells are highly accessible from autologous sources and their immunological profile is unique, they are ideal for therapeutic approaches. Optimization of administrative routes requires more investigation own to the lack of a standard protocol.

  9. Photoelectrochemical cell

    Energy Technology Data Exchange (ETDEWEB)

    Rauh, R. David (Newton, MA); Boudreau, Robert A. (Norton, MA)

    1983-06-14

    A photoelectrochemical cell comprising a sealed container having a light-transmitting window for admitting light into the container across a light-admitting plane, an electrolyte in the container, a photoelectrode in the container having a light-absorbing surface arranged to receive light from the window and in contact with the electrolyte, the surface having a plurality of spaced portions oblique to the plane, each portion having dimensions at least an order of magnitude larger than the maximum wavelength of incident sunlight, the total surface area of the surface being larger than the area of the plane bounded by the container, and a counter electrode in the container in contact with the electrolyte.

  10. nduced pluripotent stem cells and cell therapy

    Directory of Open Access Journals (Sweden)

    Banu İskender

    2013-12-01

    Full Text Available Human embryonic stem cells are derived from the inner cell mass of a blastocyst-stage embryo. They hold a huge promise for cell therapy with their self-renewing ability and pluripotency, which is known as the potential to differentiate into all cell types originating from three embryonic germ layers. However, their unique pluripotent feature could not be utilised for therapeutic purposes due to the ethical and legal problems during derivation. Recently, it was shown that the cells from adult tissues could be reverted into embryonic state, thereby restoring their pluripotent feature. This has strenghtened the possiblity of directed differentition of the reprogrammed somatic cells into the desired cell types in vitro and their use in regenerative medicine. Although these cells were termed as induced pluripotent cells, the mechanism of pluripotency has yet to be understood. Still, induced pluripotent stem cell technology is considered to be significant by proposing novel approaches in disease modelling, drug screening and cell therapy. Besides their self-renewing ability and their potential to differentiate into all cell types in a human body, they arouse a great interest in scientific world by being far from the ethical concerns regarding their embryonic counterparts and their unique feature of being patient-specific in prospective cell therapies. In this review, induced pluripotent stem cell technology and its role in cell-based therapies from past to present will be discussed. J Clin Exp Invest 2013; 4 (4: 550-561

  11. Modeling cell-in-cell structure into its biological significance

    OpenAIRE

    He, M-f; Wang, S.; Wang, Y; Wang, X-N.

    2013-01-01

    Although cell-in-cell structure was noted 100 years ago, the molecular mechanisms of ‘entering' and the destination of cell-in-cell remain largely unclear. It takes place among the same type of cells (homotypic cell-in-cell) or different types of cells (heterotypic cell-in-cell). Cell-in-cell formation affects both effector cells and their host cells in multiple aspects, while cell-in-cell death is under more intensive investigation. Given that cell-in-cell has an important role in maintainin...

  12. Tumor cell "dead or alive": caspase and survivin regulate cell death, cell cycle and cell survival.

    Science.gov (United States)

    Suzuki, A; Shiraki, K

    2001-04-01

    Cell death and cell cycle progression are two sides of the same coin, and these two different phenomenons are regulated moderately to maintain the cellular homeostasis. Tumor is one of the disease states produced as a result of the disintegrated regulation and is characterized as cells showing an irreversible progression of cell cycle and a resistance to cell death signaling. Several investigations have been performed for the understanding of cell death or cell cycle, and cell death research has remarkably progressed in these 10 years. Caspase is a nomenclature referring to ICE/CED-3 cysteine proteinase family and plays a central role during cell death. Recently, several investigations raised some possible hypotheses that caspase is also involved in cell cycle regulation. In this issue, therefore, we review the molecular basis of cell death and cell cycle regulated by caspase in tumor, especially hepatocellular carcinoma cells.

  13. Cell culture purity issues and DFAT cells

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shengjuan [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China); Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States); Bergen, Werner G. [Program in Cellular and Molecular Biosciences/Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States); Hausman, Gary J. [Animal Science Department, University of Georgia, Athens, GA 30602-2771 (United States); Zan, Linsen, E-mail: zanls@yahoo.com.cn [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China); Dodson, Michael V., E-mail: dodson@wsu.edu [Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States)

    2013-04-12

    Highlights: •DFAT cells are progeny cells derived from dedifferentiated mature adipocytes. •Common problems in this research is potential cell contamination of initial cultures. •The initial cell culture purity is crucial in DFAT cell research field. -- Abstract: Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture.

  14. Electrochemical cell

    Energy Technology Data Exchange (ETDEWEB)

    Heuts, J.J.F.G.; Willems, J.J.G.S.A.

    1987-10-13

    An electrochemical cell is described comprising a negative electrode. The electrochemically active material of which consists of an intermetallic compound forming a hydride with hydrogen, which compound has the CaCu/sub 5/-structure and the compositional formula AB/sub m/C/sub n/, where m+n is between 4.8 and 5.4, where n is between 0.05 and 0.6, in which A consists of Misch-metal or of one or more elements selected from the group consisting of Y, Ti, Hf, Zr, Ca, Th, La and the remaining rare earth metals, in which the total atomic quantities of the elements Y, Ti, Hf and Zr may not be more than 40% of A. B consists of two or more elements selected from the group formed by Ni, Co, Cu, Fe and Mn, where the maximum atomic quantity per gram atom of A is for Ni: 3.5, for Co:3.5, for Cu:3.5, for Fe:2.0 and for Mn:1.0, and C consists of one or more elements selected from the group formed by Al, Cr and Si in the indicated atomic quantities: Al:0.05-0.6, Cr:0.05-0.5 and Si:0.05-0.5, characterized in that the electrochemically active material additionally comprises one or more metals selected from the group formed by Pd, Pt, Ir and Rh, the atomic quantity per gram atom of A being from 0.001 to 0.5.

  15. CELL RESEARCH

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    REVIEWSInducible resistance to Fas-mediated apoptosis in B cells…………………………………ROTHSTEIN Thomas L (245)Executionary pathway for apoptosis: lessons from mutant mice………………………………………WOO Minna, Razqallah Hakem, Tak W Mak (267)The SHP-2 tyrosine phosphatase: Signaling mechanisms and biological functions…………………………………QU Cheng Kui (279)REGULAR ARTICLESTemperature dependent expression of cdc2 and cyclin B1 in spermatogenic cells during spermatogenesis…………………………KONG Wei Hua, Zheng GU, Jining LU, Jiake TSO (289)Transgenic mice overexpressing γ-aminobutyric acid transporter subtype I develop obesity…………………………………MA Ying Hua, Jia Hua HU, Xiao Gang ZHOU, Ruo Wang ZENG, Zhen Tong MEI, Jian FEI, Li He GUO (303)Genetic aberration in primary hepatocellular carcinoma: correlation between p53 gene mutation and loss-of-heterozygosity on chromosome 16q21-q23 and 9p21-p23………………………………………WANG Gang, Chang Hui HUANG, Yan ZHAO, Ling CAI, Ying WANG, Shi Jin XIU, Zheng Wen JIANG, Shuang YANG, Xin Tai ZHAO, Wei HUANG, Jian Ren GU (311)Identification and genetic mapping of four novel genes that regulate leaf deve- lopment in Arabidopsis………………………………………………SUN Yue, Wei ZHANG, Feng Ling LI, Ying Li GUO, Tian Lei LIU, Hai HUANG (325)NOTICE FOR CONTRIBUTORS…………………………………(337)CONTENTS of Vol. 10, 2000…………………………………………………(338)

  16. Cell culture purity issues and DFAT cells.

    Science.gov (United States)

    Wei, Shengjuan; Bergen, Werner G; Hausman, Gary J; Zan, Linsen; Dodson, Michael V

    2013-04-12

    Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture.

  17. Cell Membrane Softening in Cancer Cells

    Science.gov (United States)

    Schmidt, Sebastian; Händel, Chris; Käs, Josef

    Biomechanical properties are useful characteristics and regulators of the cell's state. Current research connects mechanical properties of the cytoskeleton to many cellular processes but does not investigate the biomechanics of the plasma membrane. We evaluated thermal fluctuations of giant plasma membrane vesicles, directly derived from the plasma membranes of primary breast and cervical cells and observed a lowered rigidity in the plasma membrane of malignant cells compared to non-malignant cells. To investigate the specific role of membrane rigidity changes, we treated two cell lines with the Acetyl-CoA carboxylase inhibitor Soraphen A. It changed the lipidome of cells and drastically increased membrane stiffness by up regulating short chained membrane lipids. These altered cells had a decreased motility in Boyden chamber assays. Our results indicate that the thermal fluctuations of the membrane, which are much smaller than the fluctuations driven by the cytoskeleton, can be modulated by the cell and have an impact on adhesion and motility.

  18. Mammary stem cells have myoepithelial cell properties.

    Science.gov (United States)

    Prater, Michael D; Petit, Valérie; Alasdair Russell, I; Giraddi, Rajshekhar R; Shehata, Mona; Menon, Suraj; Schulte, Reiner; Kalajzic, Ivo; Rath, Nicola; Olson, Michael F; Metzger, Daniel; Faraldo, Marisa M; Deugnier, Marie-Ange; Glukhova, Marina A; Stingl, John

    2014-10-01

    Contractile myoepithelial cells dominate the basal layer of the mammary epithelium and are considered to be differentiated cells. However, we observe that up to 54% of single basal cells can form colonies when seeded into adherent culture in the presence of agents that disrupt actin-myosin interactions, and on average, 65% of the single-cell-derived basal colonies can repopulate a mammary gland when transplanted in vivo. This indicates that a high proportion of basal myoepithelial cells can give rise to a mammary repopulating unit (MRU). We demonstrate that myoepithelial cells, flow-sorted using two independent myoepithelial-specific reporter strategies, have MRU capacity. Using an inducible lineage-tracing approach we follow the progeny of myoepithelial cells that express α-smooth muscle actin and show that they function as long-lived lineage-restricted stem cells in the virgin state and during pregnancy.

  19. GSPEL - Fuel Cell Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Fuel Cell Lab (FCL) Provides testing for technology readiness of fuel cell systems The FCL investigates, tests and verifies the performance of fuel-cell systems...

  20. Cell sheet engineering

    Directory of Open Access Journals (Sweden)

    Masayuki Yamato

    2004-05-01

    Full Text Available We have developed ‘cell sheet engineering’ in order to avoid the limitations of tissue reconstruction using biodegradable scaffolds or single cell suspension injection. Our concept is tissue reconstruction, not from single cells, but from cell sheets. Cell sheets are prepared using temperature-responsive culture dishes. Temperature-responsive polymers are covalently grafted onto the dishes, allowing various types of cells to adhere and proliferate at 37°C. The cells spontaneously detach when the temperature is reduced below 32°C without the need for proteolytic enzymes. The confluent cells are noninvasively harvested as single, contiguous cell sheets with intact cell-cell junctions and deposited extracellular matrix (ECM. We have used these harvested cell sheets for various tissue reconstructions, including ocular surfaces, periodontal ligaments, cardiac patches, and bladder augmentation.

  1. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  2. GSPEL - Fuel Cell Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Fuel Cell Lab (FCL)Provides testing for technology readiness of fuel cell systems The FCL investigates, tests and verifies the performance of fuel-cell systems...

  3. Fuel cells: A survey

    Science.gov (United States)

    Crowe, B. J.

    1973-01-01

    A survey of fuel cell technology and applications is presented. The operating principles, performance capabilities, and limitations of fuel cells are discussed. Diagrams of fuel cell construction and operating characteristics are provided. Photographs of typical installations are included.

  4. CellFinder: a cell data repository.

    Science.gov (United States)

    Stachelscheid, Harald; Seltmann, Stefanie; Lekschas, Fritz; Fontaine, Jean-Fred; Mah, Nancy; Neves, Mariana; Andrade-Navarro, Miguel A; Leser, Ulf; Kurtz, Andreas

    2014-01-01

    CellFinder (http://www.cellfinder.org) is a comprehensive one-stop resource for molecular data characterizing mammalian cells in different tissues and in different development stages. It is built from carefully selected data sets stemming from other curated databases and the biomedical literature. To date, CellFinder describes 3394 cell types and 50 951 cell lines. The database currently contains 3055 microscopic and anatomical images, 205 whole-genome expression profiles of 194 cell/tissue types from RNA-seq and microarrays and 553 905 protein expressions for 535 cells/tissues. Text mining of a corpus of >2000 publications followed by manual curation confirmed expression information on ∼900 proteins and genes. CellFinder's data model is capable to seamlessly represent entities from single cells to the organ level, to incorporate mappings between homologous entities in different species and to describe processes of cell development and differentiation. Its ontological backbone currently consists of 204 741 ontology terms incorporated from 10 different ontologies unified under the novel CELDA ontology. CellFinder's web portal allows searching, browsing and comparing the stored data, interactive construction of developmental trees and navigating the partonomic hierarchy of cells and tissues through a unique body browser designed for life scientists and clinicians.

  5. Snail modulates cell metabolism in MDCK cells

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Misako, E-mail: haraguci@m3.kufm.kagoshima-u.ac.jp [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Indo, Hiroko P. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Iwasaki, Yasumasa [Health Care Center, Kochi University, Kochi 780-8520 (Japan); Iwashita, Yoichiro [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Fukushige, Tomoko [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Majima, Hideyuki J. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Izumo, Kimiko; Horiuchi, Masahisa [Department of Environmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Kanekura, Takuro [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Furukawa, Tatsuhiko [Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Ozawa, Masayuki [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan)

    2013-03-22

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O{sub 2} consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of

  6. Cell aggregation and sedimentation.

    Science.gov (United States)

    Davis, R H

    1995-01-01

    The aggregation of cells into clumps or flocs has been exploited for decades in such applications as biological wastewater treatment, beer brewing, antibiotic fermentation, and enhanced sedimentation to aid in cell recovery or retention. More recent research has included the use of cell aggregation and sedimentation to selectively separate subpopulations of cells. Potential biotechnological applications include overcoming contamination, maintaining plasmid-bearing cells in continuous fermentors, and selectively removing nonviable hybridoma cells from perfusion cultures.

  7. Cell control report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This extensive report provides an essential overview of cells and their use as factory automation building blocks. The following issues are discussed in depth: Cell integration Cell software and standards Future technologies applied to cells Plus Cell control applications including: - rotary parts manufacturing - diesel engine component development - general cell control development at the General Electric Corporation - a vendor list.

  8. Nanostructured Solar Cells

    Science.gov (United States)

    Chen, Guanying; Ning, Zhijun; Ågren, Hans

    2016-01-01

    We are glad to announce the Special Issue “Nanostructured Solar Cells”, published in Nanomaterials. This issue consists of eight articles, two communications, and one review paper, covering major important aspects of nanostructured solar cells of varying types. From fundamental physicochemical investigations to technological advances, and from single junction solar cells (silicon solar cell, dye sensitized solar cell, quantum dots sensitized solar cell, and small molecule organic solar cell) to tandem multi-junction solar cells, all aspects are included and discussed in this issue to advance the use of nanotechnology to improve the performance of solar cells with reduced fabrication costs.

  9. Squamous cell skin cancer

    Science.gov (United States)

    ... that reflect light more, such as water, sand, concrete, and areas that are painted white. The higher ... - skin - squamous cell; Skin cancer - squamous cell; Nonmelanoma skin cancer - squamous ...

  10. Cell mechanics: a dialogue

    Science.gov (United States)

    Tao, Jiaxiang; Li, Yizeng; Vig, Dhruv K.; Sun, Sean X.

    2017-03-01

    Under the microscope, eukaryotic animal cells can adopt a variety of different shapes and sizes. These cells also move and deform, and the physical mechanisms driving these movements and shape changes are important in fundamental cell biology, tissue mechanics, as well as disease biology. This article reviews some of the basic mechanical concepts in cells, emphasizing continuum mechanics description of cytoskeletal networks and hydrodynamic flows across the cell membrane. We discuss how cells can generate movement and shape changes by controlling mass fluxes at the cell boundary. These mass fluxes can come from polymerization/depolymerization of actin cytoskeleton, as well as osmotic and hydraulic pressure-driven flow of water across the cell membrane. By combining hydraulic pressure control with force balance conditions at the cell surface, we discuss a quantitative mechanism of cell shape and volume control. The broad consequences of this model on cell mechanosensation and tissue mechanics are outlined.

  11. Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Nora [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Vereb, Zoltan; Rajnavoelgyi, Eva [Department of Immunology, Medical and Health Science Centre, University of Debrecen, Debrecen (Hungary); Nemet, Katalin; Uher, Ferenc; Sarkadi, Balazs [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Apati, Agota, E-mail: apati@kkk.org.hu [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth of undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.

  12. T-Cell Lymphoma

    Science.gov (United States)

    Getting the Facts T-Cell Lymphoma Overview Lymphoma is the most common blood cancer. The two main forms of lymphoma are Hodgkin lymphoma ... develop into lymphomas: B-lymphocytes (B-cells) and T-lymphocytes (T-cells). T-cell lymphomas account for ...

  13. Tracking adult stem cells

    NARCIS (Netherlands)

    Snippert, H.J.G.; Clevers, H.

    2011-01-01

    The maintenance of stem-cell-driven tissue homeostasis requires a balance between the generation and loss of cell mass. Adult stem cells have a close relationship with the surrounding tissue--known as their niche--and thus, stem-cell studies should preferably be performed in a physiological context,

  14. Insect Cell Culture

    NARCIS (Netherlands)

    Oers, van M.M.; Lynn, D.E.

    2010-01-01

    Insect cell cultures are widely used in studies on insect cell physiology, developmental biology and microbial pathology. In particular, insect cell culture is an indispensable tool for the study of insect viruses. The first continuously growing insect cell cultures were established from lepidoptera

  15. Ganglion cell like cells, diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Anand Shankar Ammanagi

    2013-01-01

    Full Text Available We report a case of cutaneous swelling found on the left anterior axillary fold of a 41-year-old man. Gross examination of specimen excised from the dermis showed a well-circumscribed nodule histologically composed of spindle cells with interspersed ganglion cell like cells. On hematoxylin and eosine (H and E staining it was diagnosed as ganglioneuroma. Ganglioneuromas are rare, benign, fully differentiated tumors that contain mature schwann cells, ganglion cells, fibrous tissue, and nerve fibers. They are commonly found along the paravertebral sympathetic ganglia and sometimes in the adrenal medulla. However primary cutaneous ganglioneuroma is an extremely rare tumor. Immunohistochemical workup revealed a fibroblastic origin and hence the case was diagnosed as fibromatosis with ganglion cell like fibroblasts. This case report suggests that the features considered diagnostic of ganglioneuromas can occur in other cutaneous lesions and, therefore, this diagnosis cannot be offered only on the basis of H and E.

  16. Generation of iPS Cells from Granulosa Cells.

    Science.gov (United States)

    Mao, Jian; Liu, Lin

    2016-01-01

    Various types of somatic cells can be reprogrammed to induced pluripotent stem (iPS) cells. Somatic stem cells may generate iPS cells more efficiently than do differentiated cells. We show that granulosa cells exhibit characteristic of somatic stem cells and can be reprogrammed to iPS cells more efficiently or with few factors. Here, we describe generation of mouse and pig iPS cells from granulosa cells with high efficiency.

  17. B cell helper assays.

    Science.gov (United States)

    Abrignani, Sergio; Tonti, Elena; Casorati, Giulia; Dellabona, Paolo

    2009-01-01

    Activation, proliferation and differentiation of naïve B lymphocytes into memory B cells and plasma cells requires engagement of the B cell receptor (BCR) coupled to T-cell help (1, 2). T cells deliver help in cognate fashion when they are activated upon recognition of specific MHC-peptide complexes presented by B cells. T cells can also deliver help in a non-cognate or bystander fashion, when they do not find specific MHC-peptide complexes on B cells and are activated by alternative mechanisms. T-cell dependent activation of B cells can be studied in vitro by experimental models called "B cell helper assays" that are based on the co-culture of B cells with activated T cells. These assays allow to decipher the molecular bases for productive T-dependent B cell responses. We show here examples of B cell helper assays in vitro, which can be reproduced with any subset of T lymphocytes that displays the appropriate helper signals.

  18. Mast cells enhance T cell activation: Importance of mast cell-derived TNF

    Science.gov (United States)

    Nakae, Susumu; Suto, Hajime; Kakurai, Maki; Sedgwick, Jonathon D.; Tsai, Mindy; Galli, Stephen J.

    2005-05-01

    Mast cells are not only important effector cells in immediate hypersensitivity reactions and immune responses to pathogens but also can contribute to T cell-mediated disorders. However, the mechanisms by which mast cells might influence T cells in such settings are not fully understood. We find that mast cells can enhance proliferation and cytokine production in multiple T cell subsets. Mast cell-dependent enhancement of T cell activation can be promoted by FcRI-dependent mast cell activation, TNF production by both mast cells and T cells, and mast cell-T cell contact. However, at high concentrations of cells, mast cells can promote T cell activation independent of IgE or TNF. Finally, mast cells also can promote T cell activation by means of soluble factors. These findings identify multiple mechanisms by which mast cells can influence T cell proliferation and cytokine production. allergy | asthma | autoimmunity | cytokines | immune response

  19. Sertoli-Leydig cell tumor

    Science.gov (United States)

    Sertoli-stromal cell tumor; Arrhenoblastoma; Androblastoma; Ovarian cancer - Sertoli-Leydig cell tumor ... The Sertoli cells are normally located in the male reproductive glands (the testes). They feed sperm cells. The Leydig cells, also ...

  20. Single cell mechanics of keratinocyte cells.

    Science.gov (United States)

    Lulevich, Valentin; Yang, Hsin-ya; Isseroff, R Rivkah; Liu, Gang-yu

    2010-11-01

    Keratinocytes represent the major cell type of the uppermost layer of human skin, the epidermis. Using AFM-based single cell compression, the ability of individual keratinocytes to resist external pressure and global rupturing forces is investigated and compared with various cell types. Keratinocytes are found to be 6-70 times stiffer than other cell types, such as white blood, breast epithelial, fibroblast, or neuronal cells, and in contrast to other cell types they retain high mechanic strength even after the cell's death. The absence of membrane rupturing peaks in the force-deformation profiles of keratinocytes and their high stiffness during a second load cycle suggests that their unique mechanical resistance is dictated by the cytoskeleton. A simple analytical model enables the quantification of Young's modulus of keratinocyte cytoskeleton, as high as 120-340 Pa. Selective disruption of the two major cytoskeletal networks, actin filaments and microtubules, does not significantly affect keratinocyte mechanics. F-actin is found to impact cell deformation under pressure. During keratinocyte compression, the plasma membrane stretches to form peripheral blebs. Instead of blebbing, cells with depolymerized F-actin respond to pressure by detaching the plasma membrane from the cytoskeleton underneath. On the other hand, the compression force of keratinocytes expressing a mutated keratin (cell line, KEB-7) is 1.6-2.2 times less than that for the control cell line that has normal keratin networks. Therefore, we infer that the keratin intermediate filament network is responsible for the extremely high keratinocyte stiffness and resilience. This could manifest into the rugged protective nature of the human epidermis.

  1. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  2. Lung Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Sharon R. Pine

    2008-01-01

    Full Text Available Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation pathways are maintained within distinct cancer types, and destabilization of this machinery may participate in maintenance of cancer stem cells. Characterization of lung cancer stem cells is an area of active research and is critical for developing novel therapies. This review summarizes the current knowledge on stem cell signaling pathways and cell markers used to identify the lung cancer stem cells.

  3. What are Stem Cells?

    Directory of Open Access Journals (Sweden)

    Ahmadshah Farhat

    2014-05-01

    Full Text Available   Stem cells are undifferentiated self regenerating multi potential cells. There are three types of stem cells categories by the ability to form after cells and correlated with the body’s development process. Totipotent: these stem cells can form an entire organism such as fertilized egg. Ploripotent: ploripotent cells are those that can form any cell in the body but cannot form an entire organism such as developing embryo’s totipotent cells become ploripotent  Multipotent: Multi potent stem cells are those that can only form specific cells in the body such as blood cells based. Based on the sources of stem cells we have three types of these cells: Autologous: Sources of the patient own cells are (Autologous either the cells from patient own body or his or her cord blood. For this type of transplant the physician now usually collects the periphery rather than morrow because the procedure is easier on like a bane morrow harvest it take place outside of an operating room, and the patient does not to be under general unsetting . Allogenic: Sources of stem cells from another donore are primarily relatives (familial allogenic or completely unrelated donors. Xenogenic: In these stem cells from different species are transplanted e .g striatal porcine fetal mesan cephalic (FVM xenotransplants for Parkinson’s disease. On sites of isolation such as embryo, umbilical cord and other body tissues stem cells are named embnyonic, cord blood, and adult stem cells. The scope of results and clinical application of stem cells are such as: Neurodegenerative conditions (MS,ALS, Parkinson’s, Stroke, Ocular disorders- Glaucoma, retinitis Pigmentosa (RP, Auto Immune Conditions (Lupus, MS,R. arthritis, Diabetes, etc, Viral Conditions (Hepatitis C and AIDS, Heart Disease, Adrenal Disorders, Injury(Nerve, Brain, etc, Anti aging (hair, skin, weight control, overall well being/preventive, Emotional disorders, Organ / Tissue Cancers, Blood cancers, Blood diseases

  4. Tracking adult stem cells.

    Science.gov (United States)

    Snippert, Hugo J; Clevers, Hans

    2011-02-01

    The maintenance of stem-cell-driven tissue homeostasis requires a balance between the generation and loss of cell mass. Adult stem cells have a close relationship with the surrounding tissue--known as their niche--and thus, stem-cell studies should preferably be performed in a physiological context, rather than outside their natural environment. The mouse is an attractive model in which to study adult mammalian stem cells, as numerous experimental systems and genetic tools are available. In this review, we describe strategies commonly used to identify and functionally characterize adult stem cells in mice and discuss their potential, limitations and interpretations, as well as how they have informed our understanding of adult stem-cell biology. An accurate interpretation of physiologically relevant stem-cell assays is crucial to identify adult stem cells and elucidate how they self-renew and give rise to differentiated progeny.

  5. Stem cells in urology.

    Science.gov (United States)

    Aboushwareb, Tamer; Atala, Anthony

    2008-11-01

    The shortage of donors for organ transplantation has stimulated research on stem cells as a potential resource for cell-based therapy in all human tissues. Stem cells have been used for regenerative medicine applications in many organ systems, including the genitourinary system. The potential applications for stem cell therapy have, however, been restricted by the ethical issues associated with embryonic stem cell research. Instead, scientists have explored other cell sources, including progenitor and stem cells derived from adult tissues and stem cells derived from the amniotic fluid and placenta. In addition, novel techniques for generating stem cells in the laboratory are being developed. These techniques include somatic cell nuclear transfer, in which the nucleus of an adult somatic cell is placed into an oocyte, and reprogramming of adult cells to induce stem-cell-like behavior. Such techniques are now being used in tissue engineering applications, and some of the most successful experiments have been in the field of urology. Techniques to regenerate bladder tissue have reached the clinic, and exciting progress is being made in other areas, such as regeneration of the kidney and urethra. Cell therapy as a treatment for incontinence and infertility might soon become a reality. Physicians should be optimistic that regenerative medicine and tissue engineering will one day provide mainstream treatment options for urologic disorders.

  6. Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

    Directory of Open Access Journals (Sweden)

    Quanwen Liu

    2016-01-01

    Full Text Available In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bundles. The hair-cell-like cells exhibited rapid permeation of FM1-43FX. The whole-cell patch-clamp technique was used to measure the membrane currents of cells differentiated for 7 days on chicken utricle stromal cells and analyze the biophysical properties of the hair-cell-like cells by recording membrane properties of cells. The results suggested that the hair-cell-like cells derived from inner ear multipotent cells were functional following differentiation in an enabling environment.

  7. Cell shape recognition by colloidal cell imprints

    NARCIS (Netherlands)

    Borovička, Josef; Stoyanov, S.D.; Paunov, V.N.

    2015-01-01

    The results presented in this study are aimed at the theoretical estimate of the interactions between a spherical microbial cell and the colloidal cell imprints in terms of the Derjaguin, Landau, Vervey, and Overbeek (DLVO) surface forces. We adapted the Derjaguin approximation to take into accou

  8. Pluripotent Stem Cells for Schwann Cell Engineering

    NARCIS (Netherlands)

    Ma, Ming-San; Boddeke, Erik; Copray, Sjef

    2015-01-01

    Tissue engineering of Schwann cells (SCs) can serve a number of purposes, such as in vitro SC-related disease modeling, treatment of peripheral nerve diseases or peripheral nerve injury, and, potentially, treatment of CNS diseases. SCs can be generated from autologous stem cells in vitro by recapitu

  9. Are mesenchymal stromal cells immune cells?

    NARCIS (Netherlands)

    M.J. Hoogduijn (Martin)

    2015-01-01

    textabstractMesenchymal stromal cells (MSCs) are considered to be promising agents for the treatment of immunological disease. Although originally identified as precursor cells for mesenchymal lineages, in vitro studies have demonstrated that MSCs possess diverse immune regulatory capacities. Pre-cl

  10. The cell cycle as a brake for β-cell regeneration from embryonic stem cells.

    Science.gov (United States)

    El-Badawy, Ahmed; El-Badri, Nagwa

    2016-01-13

    The generation of insulin-producing β cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic β cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle machinery. Both β cells and ES cells possess unique cell cycle machinery yet with significant contrasts. In this review, we compare the cell cycle control mechanisms in both ES cells and β cells, and highlight the fundamental differences between pluripotent cells of embryonic origin and differentiated β cells. Through critical analysis of the differences of the cell cycle between these two cell types, we propose that the cell cycle of ES cells may act as a brake for β-cell regeneration. Based on these differences, we discuss the potential of modulating the cell cycle of ES cells for the large-scale generation of functionally mature β cells in vitro. Further understanding of the factors that modulate the ES cell cycle will lead to new approaches to enhance the production of functional mature insulin-producing cells, and yield a reliable system to generate bona fide β cells in vitro.

  11. Regulatory T cells and B cells: implication on autoimmune diseases

    OpenAIRE

    Wang, Ping; Zheng, Song Guo

    2013-01-01

    The regulatory T (Treg) cells play an important role in the maintenance of homeostasis and the prevention of autoimmune diseases. Although most studies are focusing on the role of Treg cells in T cells and T cells-mediated diseases, these cells also directly affect B cells and other non-T cells. This manuscript updates the role of Treg cells on the B cells and B cell-mediated diseases. In addition, the mechanisms whereby Treg cells suppress B cell responses have been discussed.

  12. FUEL CELL ELECTRODE MATERIALS

    Science.gov (United States)

    FUEL CELL ELECTRODE MATERIALS. RAW MATERIAL SELECTION INFLUENCES POLARIZATION BUT IS NOT A SINGLE CONTROLLING FACTOR. AVAILABLE...DATA INDICATES THAT AN INTERRELATIONSHIP OF POROSITY, AVERAGE PORE VOLUME, AND PERMEABILITY CONTRIBUTES TO ELECTRODE FUEL CELL BEHAVIOR.

  13. NIA Aging Cell Repository

    Data.gov (United States)

    Federal Laboratory Consortium — To facilitate aging research on cells in culture, the NIA provides support for the NIA Aging Cell Repository, located at the Coriell Institute for Medical Research...

  14. Cell signaling review series

    Institute of Scientific and Technical Information of China (English)

    Aiming Lin; Zhenggang Liu

    2008-01-01

    @@ Signal transduction is pivotal for many, if not all, fundamental cellular functions including proliferation, differentiation, transformation and programmed cell death. Deregulation of cell signaling may result in certain types of cancers and other human diseases.

  15. Stem Cell Transplant

    Science.gov (United States)

    ... transplant is a procedure that infuses healthy blood stem cells into your body to replace your damaged or ... A bone marrow transplant is also called a stem cell transplant. A bone marrow transplant may be necessary ...

  16. Sickle cell test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003666.htm Sickle cell test To use the sharing features on this page, please enable JavaScript. The sickle cell test looks for the abnormal hemoglobin in the ...

  17. Sickle Cell Tests

    Science.gov (United States)

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Sickle Cell Tests Share this page: Was this page helpful? ... else I should know? How is it used? Sickle cell tests are used to identify the presence of ...

  18. Sickle Cell Disease Quiz

    Science.gov (United States)

    ... Websites About Us Information For... Media Policy Makers Sickle Cell Disease Quiz Language: English Español (Spanish) Recommend on ... 1. True or False: Only African Americans get sickle cell disease. A True B False 2. True or ...

  19. Sickle Cell Trait

    Science.gov (United States)

    ... Websites About Us Information For... Media Policy Makers Sickle Cell Trait Language: English Español (Spanish) Recommend on Facebook ... pass the trait on to their children. How Sickle Cell Trait is Inherited If both parents have SCT, ...

  20. Sickle cell anemia.

    OpenAIRE

    ŘÍHOVÁ, Tereza

    2013-01-01

    This thesis is about the disease called sickle cell anemia, or drepanocytosis. In this thesis is described the history of the disease, pathophysiology, laboratory features, various clinical features, diferencial diagnosis, quality of life in sickle cell anemia and therapy.

  1. Giant Cell Arteritis

    Science.gov (United States)

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  2. White Blood Cell Count

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? White Blood Cell Count Share this page: Was this page helpful? ... Count; Leukocyte Count; White Count Formal name: White Blood Cell Count Related tests: Complete Blood Count , Blood Smear , ...

  3. Sickle Cell Information Center

    Science.gov (United States)

    ... Nature, Wash Post, SciAm, CNN - Google Custom Search Sickle Cell Anemia News -- ScienceDaily January 18, 1970 Read articles summarizing medical research on sickle-cell anemia. NYT, Nature, Wash Post, SciAm, CNN - Google Custom ...

  4. Sickle Cell Disease

    Science.gov (United States)

    ... About Us Overview of CDC’s work. Advancements in Sickle Cell Disease New supplement from the American Journal of Preventive Medicine describes the state of sickle cell disease related care in the United States. Read Supplement ...

  5. Red blood cell production

    Science.gov (United States)

    ... to one part of the body or another. Red blood cells are an important element of blood. Their job ... is carried to and eliminated by the lungs. Red blood cells are formed in the red bone marrow of ...

  6. Cell phone explosion.

    Science.gov (United States)

    Atreya, Alok; Kanchan, Tanuj; Nepal, Samata; Pandey, Bhuwan Raj

    2016-03-01

    Cell phone explosions and resultant burn injuries are rarely reported in the scientific literature. We report a case of cell phone explosion that occurred when a young male was listening to music while the mobile was plugged in for charging.

  7. Mast cell proteoglycans.

    Science.gov (United States)

    Rönnberg, Elin; Melo, Fabio R; Pejler, Gunnar

    2012-12-01

    Mast cells are versatile effector cells of the immune system, contributing to both innate and adaptive immunity toward pathogens but also having profound detrimental activities in the context of inflammatory disease. A hallmark morphological feature of mast cells is their large content of cytoplasmic secretory granules, filled with numerous secretory compounds, including highly negatively charged heparin or chondroitin sulfate proteoglycans of serglycin type. These anionic proteoglycans provide the basis for the strong metachromatic staining properties of mast cells seen when applying various cationic dyes. Functionally, the mast cell proteoglycans have been shown to have an essential role in promoting the storage of other granule-contained compounds, including bioactive monoamines and different mast cell-specific proteases. Moreover, granule proteoglycans have been shown to regulate the enzymatic activities of mast cell proteases and to promote apoptosis. Here, the current knowledge of mast cell proteoglycans is reviewed.

  8. Bedrock/Core, Base, Plus, and Threshold Strategies in the JFL Context

    Science.gov (United States)

    Grainger, P. R.

    2012-01-01

    Although research into language learning strategies over the past 30 years has provided many insights into how good language learners facilitate the language learning process, few studies have targeted learners of Japanese in a foreign language learning environment. This study sought to (1) identify the spoken communication strategies used by…

  9. Bedrock geologic and structural map through the western Candor Colles region of Mars

    Science.gov (United States)

    Okubo, Chris H.

    2014-01-01

    The Candor Colles are a population of low, conical hills along the southeast flank of Ceti Mensa, in west Candor Chasma, within the Valles Marineris system of Mars (fig. 1). Ceti Mensa and the adjacent Candor Mensa are mounds of layered sedimentary deposits and are the most prominent landforms within west Candor Chasma. Prior to the arrival of the Mars Reconnaissance Orbiter (MRO) in orbit around Mars in 2006 (Zurek and Smrekar, 2007), geologic maps of the area utilized the relatively low resolution Viking Orbiter photomosaics (20–150 m/pixel). Geologic maps covering west Candor Chasma were created at scales of 1:15,000,000 for the western equatorial region of Mars (Scott and Tanaka, 1986), 1:2,000,000 for the Valles Marineris region (Witbeck and others, 1991), and 1:500,000 for the far eastern part of west Candor Chasma (Mars Transverse Mercator quadrangle–05072; Lucchitta, 1999). 

  10. Drainage of the ice-dammed Lake Tinninilik, West Greenland; implication on bedrock uplift

    DEFF Research Database (Denmark)

    Kjeldsen, Kristian Kjellerup; Khan, Shfaqat Abbas; Bjørk, Anders Anker;

    Drainage of ice-dammed lakes is regularly observed along the margin of the Greenland Ice Sheet. However, the speed of the drainage events and implications can vary depending on the size of the lakes and the local settings. Here, we assess the drainage pattern of Lake Tinninilik, dammed...

  11. Simulating Remediation of Trichloroethylene in Fractured Bedrock by Thermal Conductive Heating Using the Numerical Model TMVOC

    Science.gov (United States)

    2013-01-01

    biodegradation (Pruess and Battistelli, 2002). TMVOC allows for irregular grids to be created by using the Integral Finite Difference Method for space...with polycyclic aromatic hydrocarbons ( PAHs ), pentachlorophenol (PCP), and polychlorinated dibenzodioxins and furans (PCDD/Fs). The treatment zone was...a maximum depth of 32 m and the soil concentrations for PAHs , PCP and PCDD/Fs were measured to be an average of 30,600, 2,940 and 18 µg/kg pre

  12. Cracks in the Bedrock: Can U.S. Higher Education Remain Number One?

    Science.gov (United States)

    Lovett, Clara M.

    2002-01-01

    Explores how U.S. higher education's number one position over the last century is threatened as institutions struggle to deal with rising expectations from students and employers, which are producing chronic fiscal problems feared to be eroding the quality of teaching and research. (EV)

  13. Simulation of near-fault bedrock strong ground-motion field by explicit finite element method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-zhi; HU Jin-jun; XIE Li-li; WANG Hai-yun

    2006-01-01

    Based on presumed active fault and corresponding model, this paper predicted the near-fault ground motion filed of a scenario earthquake (Mw=6 3/4 ) in an active fault by the explicit finite element method in combination with the source time function with improved transmitting artificial boundary and with high-frequency vibration contained.The results indicate that the improved artificial boundary is stable in numerical computation and the predicted strong ground motion has a consistent characteristic with the observed motion.

  14. Vertical and horizontal bedrock displacements near Jakobshavn Isbræ due to glacial ice mass loss

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Wahr, John; Liu, Lin;

    2011-01-01

    Jakobshavn Isbræ. All stations experienced uplift, but the uplift rate at Kangia North, only 5 km from the glacier front, was about 10 mm/yr larger than the rate at Ilulissat, located only 45 km further away. This suggests that most of the uplift is due to the unloading of the Earth’s surface as Jakobshavn...... thins and loses mass. The observed rates are consistent with a glacier thinning model based on repeat altimeter surveys from NASA’s Airborne Topographic Mapper (ATM), which shows that Jakobshavn lost mass at an average rate of 22 +- 2 km3/yr between 2006 and 2009. The fact that the GPS uplift rates...

  15. Soil-gas helium and surface-waves detection of fault zones in granitic bedrock

    Indian Academy of Sciences (India)

    G K Reddy; T Seshunarayana; Rajeev Menon; P Senthil Kumar

    2010-10-01

    Fracture and fault networks are conduits that facilitate groundwater movement in hard-rock terrains.Soil-gas helium emanometry has been utilized in Wailapally watershed,near Hyderabad in southern India,for the detection of fracture and fault zones in a granite basement terrain having a thin regolith.Based on satellite imagery and geologic mapping,three sites were selected for detailed investigation.High spatial resolution soil-gas samples were collected at every one meter at a depth of <1.5m along 100 m long profiles (3 in number).In addition,deep shear-wave images were also obtained using the multichannel analysis of surface waves.The study clearly indicates several soil-gas helium anomalies (above 200 ppb)along the pro files,where the shear-wave velocity images also show many near-surface vertical low velocity zones.We thus interpret that the soil-gas helium anomalous zones and the vertical low-velocity zones are probable traces of fault/fracture zones that could be efficient natural recharge zones and potential groundwater conduits.The result obtained from this study demonstrates the efficacy of an integrated approach of soil-gas helium and the seismic methods for mapping groundwater resource zones in granite/gneiss provinces.

  16. Conditioning geostatistical simulations of a bedrock fluvial aquifer using single well pumping tests

    Science.gov (United States)

    Niazi, A.; Bentley, L. R.; Hayashi, M.

    2015-12-01

    Geostatistical simulation is a powerful tool to explore the uncertainty associated with heterogeneity in groundwater and reservoir studies. Nonetheless, conditioning simulations merely with lithological information does not utilize all of the available information and so some workers additionally condition simulations with flow data. In this study, we introduce an approach to condition geostatistical simulations of the Paskapoo Formation, which is a paleo-fluvial system consisting of sandstone channels embedded in mudstone. The conditioning data consist of two-hour single well pumping tests extracted from the public water well database in Alberta, Canada. In this approach, lithologic models of an entire watershed are simulated and conditioned with hard lithological data using transition probability geostatistics (TPROGS). Then, a segment of the simulation around a pumping well was used to populate a flow model (FEFLOW) with either sand or mudstone. The values of the hydraulic conductivity and specific storage of sand and mudstone were then adjusted to minimize the difference between simulated and actual pumping test data using the parameter estimation program PEST. If the simulated data do not adequately match the measured data, the lithologic model is updated by locally deforming the lithology distribution using the probability perturbation method (PPM) and the model parameters are again updated with PEST. This procedure is repeated until the simulated and measured data agree within a pre-determined tolerance. The procedure is repeated for each pumping well that has pumping test data. The method constrains the lithological simulations and provides estimates of hydraulic conductivity and specific storage that are consistent with the pumping test data. Eventually, the simulations will be combined in watershed scale groundwater models.

  17. Dating methods and geochronology of fractures and movements in bedrock: a review

    Energy Technology Data Exchange (ETDEWEB)

    Tullborg, E.L. [Terralogica AB, Graabo (Sweden); Larson, Sven Aake [Goeteborgs Univ. (Sweden); Morad, S. [Uppsala Univ. (Sweden)

    2001-06-01

    Constraining the absolute and relative ages of crustal movements is of fundamental importance in evaluating the potentials of a site as a repository for spent radioactive fuel. In this report a review summary of up to date absolute and relative dating methods is presented with specific attention to those methods most amenable for dating of fractures. A review of major fracture-and shear zones in the Swedish part of the Baltic Shield is also given. Since the shield has suffered a long and complicated history, geo-chronologists are faced with the problem of reactivated zones when attempting to date these. It is important to get structural control in order to make the choice of dating method since different methods may give answer to completely different questions. An integration of all geological background data is necessary in order to make the proper chose to fit the raised question.

  18. SRS BEDROCK PROBABILISTIC SEISMIC HAZARD ANALYSIS (PSHA) DESIGN BASIS JUSTIFICATION (U)

    Energy Technology Data Exchange (ETDEWEB)

    (NOEMAIL), R

    2005-12-14

    This represents an assessment of the available Savannah River Site (SRS) hard-rock probabilistic seismic hazard assessments (PSHAs), including PSHAs recently completed, for incorporation in the SRS seismic hazard update. The prior assessment of the SRS seismic design basis (WSRC, 1997) incorporated the results from two PSHAs that were published in 1988 and 1993. Because of the vintage of these studies, an assessment is necessary to establish the value of these PSHAs considering more recently collected data affecting seismic hazards and the availability of more recent PSHAs. This task is consistent with the Department of Energy (DOE) order, DOE O 420.1B and DOE guidance document DOE G 420.1-2. Following DOE guidance, the National Map Hazard was reviewed and incorporated in this assessment. In addition to the National Map hazard, alternative ground motion attenuation models (GMAMs) are used with the National Map source model to produce alternate hazard assessments for the SRS. These hazard assessments are the basis for the updated hard-rock hazard recommendation made in this report. The development and comparison of hazard based on the National Map models and PSHAs completed using alternate GMAMs provides increased confidence in this hazard recommendation. The alternate GMAMs are the EPRI (2004), USGS (2002) and a regional specific model (Silva et al., 2004). Weights of 0.6, 0.3 and 0.1 are recommended for EPRI (2004), USGS (2002) and Silva et al. (2004) respectively. This weighting gives cluster weights of .39, .29, .15, .17 for the 1-corner, 2-corner, hybrid, and Greens-function models, respectively. This assessment is judged to be conservative as compared to WSRC (1997) and incorporates the range of prevailing expert opinion pertinent to the development of seismic hazard at the SRS. The corresponding SRS hard-rock uniform hazard spectra are greater than the design spectra developed in WSRC (1997) that were based on the LLNL (1993) and EPRI (1988) PSHAs. The primary reasons for this difference is the greater activity rate used in contemporary models for the Charleston source zone and proper incorporation of uncertainty and randomness in GMAMs.

  19. Discovery and implication of shock metamorphic unloading microfractures in Devonian bedrock of Taihu Lake

    Institute of Scientific and Technical Information of China (English)

    WANG; Erkang(王尔康); WAN; Yuqiu(万玉秋); XU; Shijin(徐士进)

    2002-01-01

    Sphenoidal tensile microfractures with particular patterns have been discovered in the Late Devonian quartzose sandstone in islands and peninsula of the Taihu Lake area. Microfractures present a '人'-shape collective pattern, occurring in a single row or multiple rows. The quartz crystals in the inner acute angle area of some '人'-shape microfractures have severely been non-crystallized, showing the feature of diaplectic glass. The studies show that these special microfractures were formed during the unloading process after the compression was up to the peak of an impact event.

  20. The 1:625k near-surface bedrock electrical conductivity map of the UK

    OpenAIRE

    Beamish, David

    2012-01-01

    Over the past decade, a number of high-resolution airborne geophysical surveys have been conducted across onshore UK (Peart et al., 2003; Beamish & Young, 2009). These High Resolution Airborne Resource and Environmental (HiRES) surveys have typically acquired radiometric (gamma-ray spectroscopy), magnetic and electromagnetic (conductivity) measurements at 200 m line spacings and at low altitude (< 60 m). The airborne electromagnetic (AEM) data was typically acquired at four fre...