The U.S. Geological Survey in cooperation with the Central Platte Natural Resources District is i... more The U.S. Geological Survey in cooperation with the Central Platte Natural Resources District is investigating the hydrostratigraphic framework of the High Plains aquifer in the Central Platte River basin. As part of this investigation, a comprehensive set of geophysical logs was collected from six test holes at three sites and analyzed to delineate the penetrated stratigraphic units and characterize their lithology and physical properties. Flow and fluid-property logs were collected from two wells at one of the sites and analyzed along with the other geophysical logs to determine the relative transmissivity of the High Plains aquifer units. The integrated log analysis indicated that the coarse-grained deposits of the alluvium and the upper part of the Ogallala Formation contributed more than 70 percent of the total transmissivity at this site. The lower part of the Ogallala with its moderately permeable sands and silts contributed some measureable transmissivity, as did the finegrained sandstone of the underlying Arikaree Group, likely as a result of fractures and bedding-plane partings. Neither the lower nor the upper part of the siltstone-and claystone-dominated White River Group exhibited measurable transmissivity. The integrated analysis of the geophysical logs illustrated the utility of these methods in the detailed characterization of the hydrostratigraphy of the High Plains aquifer.
Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirme... more Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages (Hays et al., 1976, doi:10.1126/science.194.4270.1121), fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles (Raymo and Huybers, 2008, doi:10.1038/nature06589). Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch (~5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming (Solomon et al., 2007). Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, ~40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to ~3° C warmer than today ( Kim and Crowley, 2000, doi:10.1029/1999PA000459) and atmospheric CO2 concentration was as high as ~400 p.p.m.v. (van der Burgh et al., 1993, doi:10.1126/science.260.5115.1788, Raymo et al., 1996, doi:10.1016/0377-8398(95)00048-8). The evidence is consistent with a new ice-sheet/ice-shelf model (Pollard and DeConto, 2009, doi:10.1038/nature07809) that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and a [...]
The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sedime... more The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sediment in Hole AND-1B, representing the past 12 m.y. of glacial history. Downhole geophysical logs were acquired to a depth of 1018 mbsf (meters below seafl oor), and are complementary to data acquired from the core. The natural gamma radiation (NGR) and magnetic susceptibility logs are particularly useful for understanding lithological and paleoenvironmental change at ANDRILL McMurdo Ice Shelf Hole AND-1B. NGR logs cover the entire interval from the seafl oor to 1018 mbsf, and magnetic susceptibility and other logs covered the open hole intervals between 692 and 1018 and 237-342 mbsf. In the upper part of AND-1B, clear alternations between low and high NGR values distinguish between diatomite (lacking minerals containing naturally radioactive K, U, and Th) and diamictite (containing K-bearing clays, K-feldspar, mica, and heavy minerals). In the lower open hole logged section, NGR and magnetic susceptibility can also distinguish claystones (rich in K-bearing clay minerals, relatively low in magnetite) and diamictites (relatively high in magnetite). Sandstones can be distinguished by their high resistivity values in AND-1B. On the basis of these three downhole logs, diamictite, claystones, and sandstones can be predicted correctly for 74% of the 692-1018 mbsf interval. The logs were then used to predict facies for the 6% of this interval that was unrecovered by coring. Given the understanding of the physical property characteristics of different facies, it is also possible to identify subtle changes in lithology from the physical properties and help refi ne parts of the lithostratigraphy, for example, the varying terrigenous content of diatomites and the transitions from subice diamictite to openwater diatomite.
The Antarctic Drilling Program (ANDRILL) successfully drilled and cored a borehole, AND-1B, benea... more The Antarctic Drilling Program (ANDRILL) successfully drilled and cored a borehole, AND-1B, beneath the McMurdo Ice Shelf and into a fl exural moat basin that surrounds Ross Island. Total drilling depth reached 1285 m below seafl oor (mbsf) with 98 percent core recovery for the detailed study of glacier dynamics. With the goal of obtaining complementary information regarding heat fl ow and permeability, which is vital to understanding the nature of marine hydrogeologic systems, a succession of three temperature logs was recorded over a fi veday span to monitor the gradual thermal recovery toward equilibrium conditions. These data were extrapolated to true, undisturbed temperatures, and they defi ne a linear geothermal gradient of 76.7 K/km from the seafl oor to 647 mbsf. Bulk thermal conductivities of the sedimentary rocks were derived from empirical mixing models and density measurements performed on core, and an average value of 1.5 W/mK ± 10 percent was determined. The corresponding estimate of heat fl ow at this site is 115 mW/m 2. This value is relatively high but is consistent with other elevated heat-fl ow data associated with the Erebus Volcanic Province. Information regarding the origin and frequency of pathways for subsurface fl uid fl ow is gleaned from drillers' records, complementary geophysical logs, and core descriptions. Only two prominent permeable zones are identifi ed and these correspond to two markedly different features within the rift basin; one is a distinct lithostratigraphic subunit consisting of a thin lava fl ow and the other is a heavily fractured interval within a single thick subunit.
The U.S. Geological Survey drilled two test holes near Cape Charles, Virginia, during May and Jun... more The U.S. Geological Survey drilled two test holes near Cape Charles, Virginia, during May and June 2004, as part of an investigation of the buried, late Eocene Chesapeake Bay impact structure. The first hole is designated as the USGS-Sustainable Technology Park test hole #1 (USGS-STP1). This test hole was abandoned at a depth of 300 ft; cuttings samples were collected, but no cores or geophysical logs were acquired. The second hole is designated as the USGS-Sustainable Technology Park test hole #2 (USGS-STP2). This test hole was drilled to a depth of 2,699 ft. Cores were collected between depths of 1,401.7 ft and 1,420.7 ft and between 2,440.0 ft and 2,699.0 ft. Cuttings samples were collected from the uncored intervals below 280-ft depth. Interim sets of geophysical logs were acquired during the drilling operation, and one final set was acquired at the end of drilling. Two wells were installed in the USGS-STP2 test hole. The deep well (designated 62G-24) was screened between 2,260 ft and 2,280 ft, and the shallow well (designated 62G-25) was screened between 1,360 ft and 1,380 ft. Groundwater salinities stabilized at 40 parts per thousand for the deep well and 20 parts per thousand for the shallow well. The geologic section encountered in the test holes consists of three main units: (1) Eocene, Oligocene, Miocene, Pliocene, and Pleistocene sands and clays are present between land surface and a depth of 1,163 ft; (2) sediment-clast breccias of the impact structure are present between depths of 1,163 ft and 2,150 ft; and (3) crystalline-clast breccias and cataclastic gneiss of the impact structure are present between depths of 2,150 ft and 2,699 ft.
Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final su... more Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final sur les eaux souterraines en Montérégie Est Juin xi Portrait des ressources en eau souterraine sur les eaux souterraines en Montérégie Est Rapport final xii Juin Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final sur les eaux souterraines en Montérégie Est Juin 2013 xiii LISTE DES ANNEXES ÉLECTRONIQUES Annexe 1 : Atlas hydrogéologique Annexe 2 : Cartes thématiques Annexe 3 : Protocoles méthodologiques Annexe 4 : Résultats des travaux de terrain Annexe 5 : Description des champs et librairies de la base de données Annexe 6 : Estimés d'utilisation d'eau à l'échelle municipale Annexe 7 : Liste des activités anthropiques sélectionnées Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final sur les eaux souterraines en Montérégie Est Juin 2013 1 Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final sur les eaux souterraines en Montérégie Est Juin 2013
A series of laboratory experiments was conducted with four ocean sediments, two biogenic oozes an... more A series of laboratory experiments was conducted with four ocean sediments, two biogenic oozes and two clays. Permeability and thermal conductivity were directly measured as a function of porosity and the testing program was designed to identify any dependence of these physical properties upon hydrostatic pressure and temperature. The results show no discernible effect of pressure, within the range of 2 to 60 MPa, upon the permeability of any of the samples. Temperature effects, from 22' to 220', upon this property are accounted for by applying a viscosity correction to the permeating seawater. Previous investigations have suggested the existence of a pressure-induced and/or a temperature-induced breakdown of the adsorbed water which surrounds clay particles, thereby promoting an increase in sediment permeability. Our experimental findings cannot confirm this phenomenon and fail to provide a satisfactory solution to the confiicting data which now exist between the pore water...
Almtrect-Laboratory equipment has been built which will measure the permeability and thermal cond... more Almtrect-Laboratory equipment has been built which will measure the permeability and thermal conductivity of deep-sea sediments at their in-sire conditions of hydrostatic pressure, temperature, and void ratio. The apparatus has the capability of uniaxially consolidating a sediment sample to simulate compaction within the sediment colunm, while exposing the specimen to hydrostatic pressures ranging from atmospheric to 62 MPa and to temperatures from 22 to 220"C. The equipment includes a hypodermic needle mounted vertically through the base of the pressure vessel from which thermal conductivity is determined by the needle probe method. The system also features a combination of dead-weight testers which produces a small hydraulic gradient across the sample and permits the measurement of sediment permeability at large hydrostatic pressures. The physical property data generated from this apparatus will be important in understanding the mechanisms of heat transfer through the ocean floor and in analysing the coupled flow of heat and pore fluid in the vicinity of a heat source, such as a radioactive waste canister, buried in the seabed.
Temperature, pressure, and spinner (TPS) logs have been recorded in several wells from the Dixie ... more Temperature, pressure, and spinner (TPS) logs have been recorded in several wells from the Dixie Valley Geothermal Reservoir in west central Nevada. A variety of well-test analyses has been performed with these data to quantify the hydrologic properties of this fault-dominated geothermal resource. Four complementary analytical techniques were employed, their individual application depending upon availability and quality of data and validity of scientific assumptions. In some instances, redundancy in methodologies was used to decouple interrelated terms. The methods were (1) step-drawdown, variable-discharge test; (2) recovery analysis; (3) damped-oscillation response; and (4) injection test. To date, TPS logs from five wells have been examined and results fall into two distinct categories. Productive, economically viable wells have permeability-thickness values on the order of 10{sup 5} millidarcy-meter (mD-m) and storativities of about 10{sup {minus}3}. Low-productivity wells, some...
Cover photo: Streambed cobbles from the Red River near Capulin Canyon, New Mexico. These cobbles ... more Cover photo: Streambed cobbles from the Red River near Capulin Canyon, New Mexico. These cobbles have been turned over to show that iron oxyhydroxide precipitates (ochre color) form below the streambed and aluminum oxyhydroxide precipitates (white) form in the water column above the streambed. The difference occurs because the pH in the stream is greater than 7.0 and the pH in the streambed is less than 5.0. The visible chemical differences indicate that acidic ground water is entering the stream.
Proceedings of the Ocean Drilling Program, 137/140 Scientific Results, 1995
A series of temperature logs was obtained from Hole 504B during Deep Sea Drilling Project (DSDP)/... more A series of temperature logs was obtained from Hole 504B during Deep Sea Drilling Project (DSDP)/Ocean Drilling Program (ODP) Legs 69, 70, 83, 92, and 111; Legs 137 and 140 provided additional opportunities to measure the temperatures in the hole five years after the thermal disturbance produced during Leg 111. The successive temperature profiles recorded over the seven-year time span between Leg 69 and Leg 111 depict a slow return to thermal equilibrium in the hole resulting principally from a gradually diminishing downward flow of cold ocean bottom water with time. Trend analysis and numerical simulations following the results of Leg 111 had forecast the gradual decay and perhaps complete cessation of downward flow by the time of Leg 137 in 1991. However, temperatures measured during Leg 137 revealed a remarkable renewal of downward flow into the hole at implied volumetric flow rates similar to those detected during Leg 83 some 10 years earlier. Moreover, the temperature log obtained during Leg 140 indicated much slower downward flows and, thus, a return to conditions approaching hydrostatic. These two latest temperature logs provide direct evidence of a highly transient and episodic hydrologic system that is contrary to previous conceptual models. Conductive heat flow in the deeper part of the hole is estimated from Leg 137 measurements to be 126.9 ± 21 mW/m 2 , a value that is consistent with the Leg 111 heat-flow estimate of 120 mW/m 2 across the same interval. A systematic reduction in conductive heat flow with depth was observed in the hole during Leg 137, as it was during Leg 111. A detailed comparison of these two data sets spanning almost five years indicates that long-term, residual cooling of the formation may have resulted from earlier drilling into the lower part of the hole.
Borehole televiewer, temperature, and flowmeter data recorded in six wells penetrating a geotherm... more Borehole televiewer, temperature, and flowmeter data recorded in six wells penetrating a geothermal reservoir associated with the Stillwater fault zone in Dixie Valley, Nevada, were used to investigate the relationship between reservoir permeability and the contemporary in situ stress field. Data from wells drilled into productive and nonproductive segments of the Stillwater fault zone indicate that permeability in all wells is dominated by a relatively small number of fractures striking parallel to the local trend of the fault. However, Coulomb failure analysis using our fracture orientations in conjunction with stress orientations and magnitudes determined by Ref. 1 suggests that fault zone permeability is high only when individual fractures as well as the overall Stillwater fault zone are optimally oriented and critically stressed for frictional failure. Fracture geometry may also play a significant role in determining reservoir productivity. The well-developed populations of low...
Although conventional borehole-flow profiles routinely are used to estimate the distribution of h... more Although conventional borehole-flow profiles routinely are used to estimate the distribution of hydraulic conductivity along boreholes in heterogeneous formations, these estimates apply only to the immediate vicinity of the borehole. Numerous studies in fractured-rock aquifers demonstrate that fracture-network connectivity is more important than local fracture permeability in determining the hydraulic conductivity of fracture rocks. Cross-borehole flow experiments, where one borehole is stressed by pumping or injection and flow is measured at discrete depth stations in adjacent boreholes, can be used to determine the properties of fracture-flow paths. A fracture-flow model is used to define characteristic type curves for simple classes of fracture connections. One of the main problems in carrying out such experiments is the potential for non-unique solutions, where a given flow response in an observation borehole can be attributed to two different kinds of fracture connections. This...
The U.S. Geological Survey in cooperation with the Central Platte Natural Resources District is i... more The U.S. Geological Survey in cooperation with the Central Platte Natural Resources District is investigating the hydrostratigraphic framework of the High Plains aquifer in the Central Platte River basin. As part of this investigation, a comprehensive set of geophysical logs was collected from six test holes at three sites and analyzed to delineate the penetrated stratigraphic units and characterize their lithology and physical properties. Flow and fluid-property logs were collected from two wells at one of the sites and analyzed along with the other geophysical logs to determine the relative transmissivity of the High Plains aquifer units. The integrated log analysis indicated that the coarse-grained deposits of the alluvium and the upper part of the Ogallala Formation contributed more than 70 percent of the total transmissivity at this site. The lower part of the Ogallala with its moderately permeable sands and silts contributed some measureable transmissivity, as did the finegrained sandstone of the underlying Arikaree Group, likely as a result of fractures and bedding-plane partings. Neither the lower nor the upper part of the siltstone-and claystone-dominated White River Group exhibited measurable transmissivity. The integrated analysis of the geophysical logs illustrated the utility of these methods in the detailed characterization of the hydrostratigraphy of the High Plains aquifer.
Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirme... more Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages (Hays et al., 1976, doi:10.1126/science.194.4270.1121), fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles (Raymo and Huybers, 2008, doi:10.1038/nature06589). Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch (~5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming (Solomon et al., 2007). Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, ~40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to ~3° C warmer than today ( Kim and Crowley, 2000, doi:10.1029/1999PA000459) and atmospheric CO2 concentration was as high as ~400 p.p.m.v. (van der Burgh et al., 1993, doi:10.1126/science.260.5115.1788, Raymo et al., 1996, doi:10.1016/0377-8398(95)00048-8). The evidence is consistent with a new ice-sheet/ice-shelf model (Pollard and DeConto, 2009, doi:10.1038/nature07809) that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and a [...]
The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sedime... more The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sediment in Hole AND-1B, representing the past 12 m.y. of glacial history. Downhole geophysical logs were acquired to a depth of 1018 mbsf (meters below seafl oor), and are complementary to data acquired from the core. The natural gamma radiation (NGR) and magnetic susceptibility logs are particularly useful for understanding lithological and paleoenvironmental change at ANDRILL McMurdo Ice Shelf Hole AND-1B. NGR logs cover the entire interval from the seafl oor to 1018 mbsf, and magnetic susceptibility and other logs covered the open hole intervals between 692 and 1018 and 237-342 mbsf. In the upper part of AND-1B, clear alternations between low and high NGR values distinguish between diatomite (lacking minerals containing naturally radioactive K, U, and Th) and diamictite (containing K-bearing clays, K-feldspar, mica, and heavy minerals). In the lower open hole logged section, NGR and magnetic susceptibility can also distinguish claystones (rich in K-bearing clay minerals, relatively low in magnetite) and diamictites (relatively high in magnetite). Sandstones can be distinguished by their high resistivity values in AND-1B. On the basis of these three downhole logs, diamictite, claystones, and sandstones can be predicted correctly for 74% of the 692-1018 mbsf interval. The logs were then used to predict facies for the 6% of this interval that was unrecovered by coring. Given the understanding of the physical property characteristics of different facies, it is also possible to identify subtle changes in lithology from the physical properties and help refi ne parts of the lithostratigraphy, for example, the varying terrigenous content of diatomites and the transitions from subice diamictite to openwater diatomite.
The Antarctic Drilling Program (ANDRILL) successfully drilled and cored a borehole, AND-1B, benea... more The Antarctic Drilling Program (ANDRILL) successfully drilled and cored a borehole, AND-1B, beneath the McMurdo Ice Shelf and into a fl exural moat basin that surrounds Ross Island. Total drilling depth reached 1285 m below seafl oor (mbsf) with 98 percent core recovery for the detailed study of glacier dynamics. With the goal of obtaining complementary information regarding heat fl ow and permeability, which is vital to understanding the nature of marine hydrogeologic systems, a succession of three temperature logs was recorded over a fi veday span to monitor the gradual thermal recovery toward equilibrium conditions. These data were extrapolated to true, undisturbed temperatures, and they defi ne a linear geothermal gradient of 76.7 K/km from the seafl oor to 647 mbsf. Bulk thermal conductivities of the sedimentary rocks were derived from empirical mixing models and density measurements performed on core, and an average value of 1.5 W/mK ± 10 percent was determined. The corresponding estimate of heat fl ow at this site is 115 mW/m 2. This value is relatively high but is consistent with other elevated heat-fl ow data associated with the Erebus Volcanic Province. Information regarding the origin and frequency of pathways for subsurface fl uid fl ow is gleaned from drillers' records, complementary geophysical logs, and core descriptions. Only two prominent permeable zones are identifi ed and these correspond to two markedly different features within the rift basin; one is a distinct lithostratigraphic subunit consisting of a thin lava fl ow and the other is a heavily fractured interval within a single thick subunit.
The U.S. Geological Survey drilled two test holes near Cape Charles, Virginia, during May and Jun... more The U.S. Geological Survey drilled two test holes near Cape Charles, Virginia, during May and June 2004, as part of an investigation of the buried, late Eocene Chesapeake Bay impact structure. The first hole is designated as the USGS-Sustainable Technology Park test hole #1 (USGS-STP1). This test hole was abandoned at a depth of 300 ft; cuttings samples were collected, but no cores or geophysical logs were acquired. The second hole is designated as the USGS-Sustainable Technology Park test hole #2 (USGS-STP2). This test hole was drilled to a depth of 2,699 ft. Cores were collected between depths of 1,401.7 ft and 1,420.7 ft and between 2,440.0 ft and 2,699.0 ft. Cuttings samples were collected from the uncored intervals below 280-ft depth. Interim sets of geophysical logs were acquired during the drilling operation, and one final set was acquired at the end of drilling. Two wells were installed in the USGS-STP2 test hole. The deep well (designated 62G-24) was screened between 2,260 ft and 2,280 ft, and the shallow well (designated 62G-25) was screened between 1,360 ft and 1,380 ft. Groundwater salinities stabilized at 40 parts per thousand for the deep well and 20 parts per thousand for the shallow well. The geologic section encountered in the test holes consists of three main units: (1) Eocene, Oligocene, Miocene, Pliocene, and Pleistocene sands and clays are present between land surface and a depth of 1,163 ft; (2) sediment-clast breccias of the impact structure are present between depths of 1,163 ft and 2,150 ft; and (3) crystalline-clast breccias and cataclastic gneiss of the impact structure are present between depths of 2,150 ft and 2,699 ft.
Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final su... more Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final sur les eaux souterraines en Montérégie Est Juin xi Portrait des ressources en eau souterraine sur les eaux souterraines en Montérégie Est Rapport final xii Juin Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final sur les eaux souterraines en Montérégie Est Juin 2013 xiii LISTE DES ANNEXES ÉLECTRONIQUES Annexe 1 : Atlas hydrogéologique Annexe 2 : Cartes thématiques Annexe 3 : Protocoles méthodologiques Annexe 4 : Résultats des travaux de terrain Annexe 5 : Description des champs et librairies de la base de données Annexe 6 : Estimés d'utilisation d'eau à l'échelle municipale Annexe 7 : Liste des activités anthropiques sélectionnées Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final sur les eaux souterraines en Montérégie Est Juin 2013 1 Portrait des ressources en eau souterraine Projet d'acquisition de connaissances Rapport final sur les eaux souterraines en Montérégie Est Juin 2013
A series of laboratory experiments was conducted with four ocean sediments, two biogenic oozes an... more A series of laboratory experiments was conducted with four ocean sediments, two biogenic oozes and two clays. Permeability and thermal conductivity were directly measured as a function of porosity and the testing program was designed to identify any dependence of these physical properties upon hydrostatic pressure and temperature. The results show no discernible effect of pressure, within the range of 2 to 60 MPa, upon the permeability of any of the samples. Temperature effects, from 22' to 220', upon this property are accounted for by applying a viscosity correction to the permeating seawater. Previous investigations have suggested the existence of a pressure-induced and/or a temperature-induced breakdown of the adsorbed water which surrounds clay particles, thereby promoting an increase in sediment permeability. Our experimental findings cannot confirm this phenomenon and fail to provide a satisfactory solution to the confiicting data which now exist between the pore water...
Almtrect-Laboratory equipment has been built which will measure the permeability and thermal cond... more Almtrect-Laboratory equipment has been built which will measure the permeability and thermal conductivity of deep-sea sediments at their in-sire conditions of hydrostatic pressure, temperature, and void ratio. The apparatus has the capability of uniaxially consolidating a sediment sample to simulate compaction within the sediment colunm, while exposing the specimen to hydrostatic pressures ranging from atmospheric to 62 MPa and to temperatures from 22 to 220"C. The equipment includes a hypodermic needle mounted vertically through the base of the pressure vessel from which thermal conductivity is determined by the needle probe method. The system also features a combination of dead-weight testers which produces a small hydraulic gradient across the sample and permits the measurement of sediment permeability at large hydrostatic pressures. The physical property data generated from this apparatus will be important in understanding the mechanisms of heat transfer through the ocean floor and in analysing the coupled flow of heat and pore fluid in the vicinity of a heat source, such as a radioactive waste canister, buried in the seabed.
Temperature, pressure, and spinner (TPS) logs have been recorded in several wells from the Dixie ... more Temperature, pressure, and spinner (TPS) logs have been recorded in several wells from the Dixie Valley Geothermal Reservoir in west central Nevada. A variety of well-test analyses has been performed with these data to quantify the hydrologic properties of this fault-dominated geothermal resource. Four complementary analytical techniques were employed, their individual application depending upon availability and quality of data and validity of scientific assumptions. In some instances, redundancy in methodologies was used to decouple interrelated terms. The methods were (1) step-drawdown, variable-discharge test; (2) recovery analysis; (3) damped-oscillation response; and (4) injection test. To date, TPS logs from five wells have been examined and results fall into two distinct categories. Productive, economically viable wells have permeability-thickness values on the order of 10{sup 5} millidarcy-meter (mD-m) and storativities of about 10{sup {minus}3}. Low-productivity wells, some...
Cover photo: Streambed cobbles from the Red River near Capulin Canyon, New Mexico. These cobbles ... more Cover photo: Streambed cobbles from the Red River near Capulin Canyon, New Mexico. These cobbles have been turned over to show that iron oxyhydroxide precipitates (ochre color) form below the streambed and aluminum oxyhydroxide precipitates (white) form in the water column above the streambed. The difference occurs because the pH in the stream is greater than 7.0 and the pH in the streambed is less than 5.0. The visible chemical differences indicate that acidic ground water is entering the stream.
Proceedings of the Ocean Drilling Program, 137/140 Scientific Results, 1995
A series of temperature logs was obtained from Hole 504B during Deep Sea Drilling Project (DSDP)/... more A series of temperature logs was obtained from Hole 504B during Deep Sea Drilling Project (DSDP)/Ocean Drilling Program (ODP) Legs 69, 70, 83, 92, and 111; Legs 137 and 140 provided additional opportunities to measure the temperatures in the hole five years after the thermal disturbance produced during Leg 111. The successive temperature profiles recorded over the seven-year time span between Leg 69 and Leg 111 depict a slow return to thermal equilibrium in the hole resulting principally from a gradually diminishing downward flow of cold ocean bottom water with time. Trend analysis and numerical simulations following the results of Leg 111 had forecast the gradual decay and perhaps complete cessation of downward flow by the time of Leg 137 in 1991. However, temperatures measured during Leg 137 revealed a remarkable renewal of downward flow into the hole at implied volumetric flow rates similar to those detected during Leg 83 some 10 years earlier. Moreover, the temperature log obtained during Leg 140 indicated much slower downward flows and, thus, a return to conditions approaching hydrostatic. These two latest temperature logs provide direct evidence of a highly transient and episodic hydrologic system that is contrary to previous conceptual models. Conductive heat flow in the deeper part of the hole is estimated from Leg 137 measurements to be 126.9 ± 21 mW/m 2 , a value that is consistent with the Leg 111 heat-flow estimate of 120 mW/m 2 across the same interval. A systematic reduction in conductive heat flow with depth was observed in the hole during Leg 137, as it was during Leg 111. A detailed comparison of these two data sets spanning almost five years indicates that long-term, residual cooling of the formation may have resulted from earlier drilling into the lower part of the hole.
Borehole televiewer, temperature, and flowmeter data recorded in six wells penetrating a geotherm... more Borehole televiewer, temperature, and flowmeter data recorded in six wells penetrating a geothermal reservoir associated with the Stillwater fault zone in Dixie Valley, Nevada, were used to investigate the relationship between reservoir permeability and the contemporary in situ stress field. Data from wells drilled into productive and nonproductive segments of the Stillwater fault zone indicate that permeability in all wells is dominated by a relatively small number of fractures striking parallel to the local trend of the fault. However, Coulomb failure analysis using our fracture orientations in conjunction with stress orientations and magnitudes determined by Ref. 1 suggests that fault zone permeability is high only when individual fractures as well as the overall Stillwater fault zone are optimally oriented and critically stressed for frictional failure. Fracture geometry may also play a significant role in determining reservoir productivity. The well-developed populations of low...
Although conventional borehole-flow profiles routinely are used to estimate the distribution of h... more Although conventional borehole-flow profiles routinely are used to estimate the distribution of hydraulic conductivity along boreholes in heterogeneous formations, these estimates apply only to the immediate vicinity of the borehole. Numerous studies in fractured-rock aquifers demonstrate that fracture-network connectivity is more important than local fracture permeability in determining the hydraulic conductivity of fracture rocks. Cross-borehole flow experiments, where one borehole is stressed by pumping or injection and flow is measured at discrete depth stations in adjacent boreholes, can be used to determine the properties of fracture-flow paths. A fracture-flow model is used to define characteristic type curves for simple classes of fracture connections. One of the main problems in carrying out such experiments is the potential for non-unique solutions, where a given flow response in an observation borehole can be attributed to two different kinds of fracture connections. This...
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Papers by Roger Morin