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Geophysical investigations at the engine test area of Camp Crowder, Missouri.

Description: Camp Crowder, which is located south of Neosho, Missouri, is currently a Missouri Army National Guard training facility (Figure 1). The site was established as Camp Crowder during World War II and served as a U.S. Army Signal Corps Replacement Training Center. During the height of the war, Camp Crowder occupied an area of about 43,000 acres, which is much larger than its current dimensions. From 1957 to 1972, a portion of Camp Crowder was operated for the federal government as a rocket and jet engine manufacturing plant and testing area. One testing area was known as the ETA (ETA) and remains a part of Camp Crowder (Figure 2). The other test area was termed the Components Test Area (CTA) and is now privately owned. Recent site investigations have indicated that contamination is present in both the soil and groundwater at the ETA and the CTA (Rust 1993). Dye tracer studies conducted on and near Camp Crowder show that the site provides groundwater recharge to several nearby springs (Vandike and Brookshire 1996). Photogeologic analysis by Frano (1999) indicates the presence of several lineament sets, which are likely to represent fracture systems in the underlying bedrock. Argonne National Laboratory (ANL) has been tasked to identify and apply appropriate geophysical techniques that will assist in the development of a more thorough understanding of the complex interrelationships between groundwater flow and geologic structure at the Camp Crowder site. The specific goal of this effort is to locate zones for preferential groundwater and/or contaminant migration.
Date: August 11, 2000
Creator: Miller, S. F.; Thompson, M. D.; Cooper, J. M. & Mandell, W.
Partner: UNT Libraries Government Documents Department

Phase II environmental geophysics at J-Field, Aberdeen Proving Ground, Maryland

Description: Geophysical studies were conducted at eight sites on the tip of Gunpowder Neck (J-Field) in the Edgewood Area of Aberdeen Proving Ground, Maryland. The results of the studies were used to delineate the extent of three former burning pits and help determine the necessity of further investigation at five potential areas of concern (PAOCs). Intensive investigations were performed at the three former burning pits and two of the PAOCs by using electromagnetic (EM-31 and EM-61), total field magnetometry, and ground-penetrating radar geophysical techniques. The successful integration of the four data sets characterized the extent, the approximate depth and nature of fill material, and the location of metallic debris at the three former burning pits. At the two PAOC sites that were intensively investigated, no continuous areas of metallic debris, indicating organized burials, were present. Less extensive exploratory profiles conducted at three other PAOC sites indicated the presence of buried metal objects, but they were inconclusive in defining the nature and extent of buried materials.
Date: September 1995
Creator: Davies, B. E.; Thompson, M. D. & Yuen, C. R.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5476 decommissiong, Aberdeen Proving Ground

Description: Building E5476 was one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The large number of magnetic sources surrounding the building are believed to be contained in construction fill. The smaller anomalies, for the most part, were not imaged with ground radar or by electrical profiling. Large magnetic anomalies near the southwest comer of the building are due to aboveground standpipes and steel-reinforced concrete. Two high-resistivity areas, one projecting northeast from the building and another south of the original structure, may indicate the presence of organic pore fluids in the subsurface. A conductive lineament protruding from the south wall that is enclosed by the southem, high-resistivity feature is not associated with an equivalent magnetic anomaly. Magnetic and electrical anomalies south of the old landfill boundary are probably not associated with the building. The boundary is marked by a band of magnetic anomalies and a conductive zone trending northwest to southeast. The cause of high resistivities in a semicircular area in the southwest comer, within the landfill area, is unexplained.
Date: November 1, 1992
Creator: Miller, S.F.; Thompson, M.D.; McGinnis, M.G. & McGinnis, L.D.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5440 decommissioning, Aberdeen Proving Ground

Description: Building E5440 was one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The results show several complex geophysical signatures. Isolated, one-point, magnetic anomalies surrounding the building may be associated with construction fill. A 10-ft-wide band of strongly magnetic positive anomalies bordering the north side of the building obliterates small magnetic sources that might otherwise be seen. A prominent magnetic nose'' extending northward from this band toward a standpipe at 100N,63E may be connected to an underground tank. The southeast corner of the site is underlain by a rectangular, magnetized source associated with strong radar images. A magnetic lineament extending south from the anomaly may be caused by a buried pipe; the anomaly itself may be caused by subsurface equipment associated with a manhole or utility access pit. A 2,500-gamma, positive magnetic anomaly centered at 0N,20E, which is also the location of a 12 [Omega]-m resistivity minimum, may be caused by a buried vault. It appears on radar imaging as a strong reflector.
Date: November 1, 1992
Creator: McGinnis, L.D.; Miller, S.F.; Thompson, M.D. & McGinnis, M.G.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5481 decommissioning, Aberdeen Proving Ground

Description: Building E5481 is one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The building is located on the northern margin of a landfill that was sited in a wetland. The large number of magnetic sources surrounding the building are believed to be contained in construction fill that had been used to raise the grade. The smaller anomalies, for the most part, are not imaged with ground radar or by electrical profiling. A conductive zone trending northwest to southeast across the site is spatially related to an old roadbed. Higher resistivity areas in the northeast and east are probably representive of background values. Three high-amplitude, positive, rectangular magnetic anomalies have unknown sources. The features do not have equivalent electrical signatures, nor are they seen with radar imaging.
Date: November 1, 1992
Creator: Thompson, M.D.; McGinnis, M.G.; McGinnis, L.D. & Miller, S.F.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5190 decommissioning, Aberdeen Proving Ground

Description: Building E5190 is one of ten potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. A noninvasive geophysical survey, including the complementary technologies of magnetics, electrical resistivity, and ground-penetrating radar, was conducted around the perimeter as a guide to developing a sampling and monitoring program prior to decommissioning and dismantling the building. The magnetics surveys indicated that multistation, positive magnetic sources are randomly distributed north and west of the building. Two linear trends were noted: one that may outline buried utility lines and another that is produced by a steel-covered trench. The resistivity profiling indicated three conductive zones: one due to increased moisture in a ditch, one associated with buried utility lines, and a third zone associated with the steel-covered trench. Ground-penetrating radar imaging detected two significant anomalies, which were correlated with small-amplitude magnetic anomalies. The objectives of the study -- to detect and locate objects and to characterize a located object were achieved.
Date: July 1, 1992
Creator: Miller, S.F.; Thompson, M.D.; McGinnis, M.G. & McGinnis, L.D.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5282 decommissioning, Aberdeen Proving Ground

Description: This report discusses Building E5282 which was one of 10 potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. Magnetic surveys identified small, complicated, multiple anomalies west, north, and northeast of the building that may be caused by construction fill. Two underground storage tanks, at the northeast and southeast corners, were identified. A large magnetic anomaly complex east of the building was caused by aboveground pipes and unexploded ordnance fragments scattered at the surface. Electrical resistivity profiling showed a broad, conductive terrain superimposed over magnetic anomalies on the north and west. A broad, high-resistivity, nonmagnetic area centered 25 ft east of the building has an unknown origin, but it may be due to nonconductive organic liquids, construction fill, or a buried concrete slab; GPR imaging showed this area as a highly reflective zone at a depth of about 5 ft. The GPR data also showed a small-diameter pipe oriented north-south located east of the building.
Date: August 1, 1992
Creator: Thompson, M.D.; McGinnis, M.G.; McGinnis, L.D. & Miller, S.F.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5375 decommissioning, Aberdeen Proving Ground

Description: Building E5375 was one of ten potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. Several anomalies wear, noted: (1) An underground storage tank located 25 ft east of Building E5375 was identified with magnetic, resistivity, and GPR profiling. (2) A three-point resistivity anomaly, 12 ft east of the northeast comer of Building E5374 (which borders Building E5375) and 5 ft south of the area surveyed with the magnetometer, may be caused by another underground storage tank. (3) A 2,500-gamma magnetic anomaly near the northeast corner of the site has no equivalent resistivity anomaly, although disruption in GPR reflectors was observed. (4) A one-point magnetic anomaly was located at the northeast comer, but its source cannot be resolved. A chaotic reflective zone to the east represents the radar signature of Building E5375 construction fill.
Date: August 1, 1992
Creator: McGinnis, M.G.; McGinnis, L.D.; Miller, S.F. & Thompson, M.D.
Partner: UNT Libraries Government Documents Department

Interim progress report addendun - environmental geophysics: Building E5032 decommissioning, Aberdeen Proving Ground, January 1994 resurvey

Description: Geophysical surveying around Building E5032 using three new continuously recording geophysical instruments - two types of electromagnetic induction instruments and a cesium vapor magnetometer that were unavailable at the time of the original survey - has provided additional information for defining the location of buried debris, vaults, tanks, and the drainage/sump system near the building. The dominant geophysical signature around Building E5032 consists of a complex pattern of linear magnetic, electrical-conductivity, and electromagnetic field anomalies that appear to be associated with drainage/sewer systems, ditches, past railway activity, the location for Building T5033 (old number 99A), and the probable location of Building 91. Integrated analysis of data acquired using the three techniques, plus a review of the existing ground-penetrating-radar data, allow a more thorough definition of the sources for the observed anomalies.
Date: December 1, 1994
Creator: Thompson, M.D.; McGinnis, L.D.; Benson, M.A.; Borden, H.M. & Padar, C.A.
Partner: UNT Libraries Government Documents Department

Geophysical exploration in the Lautertal at the Combat Maneuver Training Center, Hohenfels, Germany

Description: Geophysical exploration was conducted in the Lautertal at the Combat Maneuver Training Center, Hohenfels, Germany, to determine the shallow geological framework of a typical dry valley in this karstic environment. The complementary methods of electromagnetic surveying, vertical electrical soundings, and seismic refraction profiling were successful in determining the depth and configuration of the bedrock surface, the character of the unconsolidated deposits resting on the bedrock surface, and the nature of the bedrock surface. Channels and other depressions in the bedrock surface are aligned with structurally induced fractures in the bedrock. The unconsolidated deposits consist of coarse alluvium and colluvium, which are confined to these channels and other depressions, and fine-grained loam and loess, which cover most of the Lautertal. Wide ranges in the electrical and elastic parameters of the bedrock surface are indicative of carbonate rock that is highly fractured and dissolved at some locations and competent at others. Most local groundwater recharge occurs in the uplands where the Middle Kimmeridge (Delta) Member of the Maim Formation (Jurassic) is widely exposed. These carbonate rocks are known to be susceptible to dissolution along the fractures and joints; thus, they offer meteoric waters ready access to the main shallow aquifers lower in the Malm Formation. These same rocks also form the bedrock surface below many of the dry valleys, but in the Lautertal, the infiltration of meteoric waters into the subsurface is generally impeded by the surficial layer of fine-grained loam and loess, which have low hydraulic conductivity. Further, the rocks of the Middle Kimmeridge Member appear to be closely associated with the localized occurrence of turbidity in such perennial streams as the Lauterach.
Date: October 1, 1994
Creator: Heigold, P.C.; Thompson, M.D. & Borden, H.M.
Partner: UNT Libraries Government Documents Department

Assessing environmental risk of the retired filter bed area, Battelle West Jefferson

Description: Initial investigations conducted by the U.S. Department of Energy, Chicago Operations Office, and by Argonne National Laboratory used seismic refraction profiling, electrical resistivity depth sounding, conductivity profiling, magnetic gradiometry, and ground-penetrating radar to study environmental geophysics in the area of the Battelle West Jefferson site`s radiologically contaminated retired filter beds. The investigators used a combination of nonintrusive technologies and innovative drilling techniques to assess environmental risk at the filter beds and to improve understanding of the geology of the Big Darby Creek floodplain. The geophysical investigation, which showed that the preferred groundwater pathway is associated with a laterally extensive deposit of silty sand to sand that is less than 12 ft deep in the floodplain area, also guided the location of cone penetrometer test sites and piezometer installation. Cone penetrometer testing was useful for comparing continuous logging data with surface geophysical data in establishing correlations among unconsolidated materials.
Date: April 1, 1997
Creator: Miller, S.F.; Thompson, M.D. & Glennon, M.A.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5375 decommissioning, Aberdeen Proving Ground. Interim progress report

Description: Building E5375 was one of ten potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. Several anomalies wear, noted: (1) An underground storage tank located 25 ft east of Building E5375 was identified with magnetic, resistivity, and GPR profiling. (2) A three-point resistivity anomaly, 12 ft east of the northeast comer of Building E5374 (which borders Building E5375) and 5 ft south of the area surveyed with the magnetometer, may be caused by another underground storage tank. (3) A 2,500-gamma magnetic anomaly near the northeast corner of the site has no equivalent resistivity anomaly, although disruption in GPR reflectors was observed. (4) A one-point magnetic anomaly was located at the northeast comer, but its source cannot be resolved. A chaotic reflective zone to the east represents the radar signature of Building E5375 construction fill.
Date: August 1, 1992
Creator: McGinnis, M. G.; McGinnis, L. D.; Miller, S. F. & Thompson, M. D.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5282 decommissioning, Aberdeen Proving Ground. Interim progress report

Description: This report discusses Building E5282 which was one of 10 potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. Magnetic surveys identified small, complicated, multiple anomalies west, north, and northeast of the building that may be caused by construction fill. Two underground storage tanks, at the northeast and southeast corners, were identified. A large magnetic anomaly complex east of the building was caused by aboveground pipes and unexploded ordnance fragments scattered at the surface. Electrical resistivity profiling showed a broad, conductive terrain superimposed over magnetic anomalies on the north and west. A broad, high-resistivity, nonmagnetic area centered 25 ft east of the building has an unknown origin, but it may be due to nonconductive organic liquids, construction fill, or a buried concrete slab; GPR imaging showed this area as a highly reflective zone at a depth of about 5 ft. The GPR data also showed a small-diameter pipe oriented north-south located east of the building.
Date: August 1, 1992
Creator: Thompson, M. D.; McGinnis, M. G.; McGinnis, L. D. & Miller, S. F.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5440 decommissioning, Aberdeen Proving Ground. Interim progress report

Description: Building E5440 was one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The results show several complex geophysical signatures. Isolated, one-point, magnetic anomalies surrounding the building may be associated with construction fill. A 10-ft-wide band of strongly magnetic positive anomalies bordering the north side of the building obliterates small magnetic sources that might otherwise be seen. A prominent magnetic ``nose`` extending northward from this band toward a standpipe at 100N,63E may be connected to an underground tank. The southeast corner of the site is underlain by a rectangular, magnetized source associated with strong radar images. A magnetic lineament extending south from the anomaly may be caused by a buried pipe; the anomaly itself may be caused by subsurface equipment associated with a manhole or utility access pit. A 2,500-gamma, positive magnetic anomaly centered at 0N,20E, which is also the location of a 12 {Omega}-m resistivity minimum, may be caused by a buried vault. It appears on radar imaging as a strong reflector.
Date: November 1, 1992
Creator: McGinnis, L. D.; Miller, S. F.; Thompson, M. D. & McGinnis, M. G.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5481 decommissioning, Aberdeen Proving Ground. Interim progress report

Description: Building E5481 is one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The building is located on the northern margin of a landfill that was sited in a wetland. The large number of magnetic sources surrounding the building are believed to be contained in construction fill that had been used to raise the grade. The smaller anomalies, for the most part, are not imaged with ground radar or by electrical profiling. A conductive zone trending northwest to southeast across the site is spatially related to an old roadbed. Higher resistivity areas in the northeast and east are probably representive of background values. Three high-amplitude, positive, rectangular magnetic anomalies have unknown sources. The features do not have equivalent electrical signatures, nor are they seen with radar imaging.
Date: November 1, 1992
Creator: Thompson, M. D.; McGinnis, M. G.; McGinnis, L. D. & Miller, S. F.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5476 decommissiong, Aberdeen Proving Ground. Interim progress report

Description: Building E5476 was one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The large number of magnetic sources surrounding the building are believed to be contained in construction fill. The smaller anomalies, for the most part, were not imaged with ground radar or by electrical profiling. Large magnetic anomalies near the southwest comer of the building are due to aboveground standpipes and steel-reinforced concrete. Two high-resistivity areas, one projecting northeast from the building and another south of the original structure, may indicate the presence of organic pore fluids in the subsurface. A conductive lineament protruding from the south wall that is enclosed by the southem, high-resistivity feature is not associated with an equivalent magnetic anomaly. Magnetic and electrical anomalies south of the old landfill boundary are probably not associated with the building. The boundary is marked by a band of magnetic anomalies and a conductive zone trending northwest to southeast. The cause of high resistivities in a semicircular area in the southwest comer, within the landfill area, is unexplained.
Date: November 1, 1992
Creator: Miller, S. F.; Thompson, M. D.; McGinnis, M. G. & McGinnis, L. D.
Partner: UNT Libraries Government Documents Department

Geophysical study of the Building 103 Dump, Aberdeen Proving Ground

Description: The Building 103 Dump is one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, resistivity, ground-penetrating radar, and seismic refraction, were conducted. These surveys indicate that much of the area is free of debris. However, prominent magnetic and resistivity anomalies occur along well-defined lineaments, suggestive of a dendritic stream pattern. Prior to the onset of dumping, the site was described as a ``sand pit,`` which suggests that headward erosion of Canal Creek tributaries cut into the surficial aquifer. Contaminants dumped into the landfill would have direct access to the surficial aquifer and thus to Canal Creek. Seismic refraction profiling indicates 6--12 ft of fill material now rests on the former land surface. Only the northern third of the former landfill was geophysically surveyed.
Date: December 1, 1992
Creator: McGinnis, L. D.; Miller, S. F.; Thompson, M. D. & McGinnis, M. G.
Partner: UNT Libraries Government Documents Department

Interim progress report -- geophysics: Decommissioning of Buildings E5974 and E5978, Aberdeen Proving Ground

Description: Buildings E5974 and E5978, located near the mouth of Canal Creek, were among 10 potentially contaminated sites in the Westwood and Canal Creek areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including the complementary technologies of magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeters of the buildings to guide a sampling program prior to decommissioning and dismantling. The magnetic anomalies and the electrically conductive areas around these buildings have a spatial relationship similar to that observed in low-lying sites in the Canal Creek area; they are probably associated with construction fill. Electrically conductive terrain is dominant on the eastern side of the site, and resistive terrain predominates on the west. The smaller magnetic anomalies are not imaged with ground radar or by electrical profiling. The high resistivities in the northwest quadrant are believed to be caused by a natural sand lens. The causes of three magnetic anomalies in the high-resistivity area are unidentified, but they are probably anthropogenic.
Date: November 1, 1992
Creator: McGinnis, M. G.; McGinnis, L. D.; Miller, S. F. & Thompson, M. D.
Partner: UNT Libraries Government Documents Department

Geophysics: Building E5190 decommissioning, Aberdeen Proving Ground. Interim progress report

Description: Building E5190 is one of ten potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. A noninvasive geophysical survey, including the complementary technologies of magnetics, electrical resistivity, and ground-penetrating radar, was conducted around the perimeter as a guide to developing a sampling and monitoring program prior to decommissioning and dismantling the building. The magnetics surveys indicated that multistation, positive magnetic sources are randomly distributed north and west of the building. Two linear trends were noted: one that may outline buried utility lines and another that is produced by a steel-covered trench. The resistivity profiling indicated three conductive zones: one due to increased moisture in a ditch, one associated with buried utility lines, and a third zone associated with the steel-covered trench. Ground-penetrating radar imaging detected two significant anomalies, which were correlated with small-amplitude magnetic anomalies. The objectives of the study -- to detect and locate objects and to characterize a located object were achieved.
Date: July 1, 1992
Creator: Miller, S. F.; Thompson, M. D.; McGinnis, M. G. & McGinnis, L. D.
Partner: UNT Libraries Government Documents Department

Environmental geophysics at Kings Creek Disposal Site and 30th Street Landfill, Aberdeen Proving Ground, Maryland

Description: Geophysical studies on the Bush River Peninsula in the Edgewood Area of Aberdeen Proving Ground, Maryland, delineate landfill areas and provide diagnostic signatures of the hydrogeologic framework and possible contaminant pathways. These studies indicate that, during the Pleistocene Epoch, alternating stands of high and low seal levels resulted in a complex pattern of shallow channel-fill deposits in the Kings Creek area. Ground-penetrating radar studies reveal a paleochannel greater than 50 ft deep, with a thalweg trending offshore in a southwest direction into Kings Creek. Onshore, the ground-penetrating radar data indicate a 35-ft-deep branch to the main channel, trending to the north-northwest directly beneath the 30th Street Landfill. Other branches are suspected to meet the offshore paleochannel in the wetlands south and east of the 30th Street Landfill. This paleochannel depositional system is environmentally significant because it may control the shallow groundwater flow regime beneath the site. Electromagnetic surveys have delineated the pre-fill lowland area currently occupied by the 30th Street Landfill. Magnetic and conductive anomalies outline surficial and buried debris throughout the study area. On the basis of geophysical data, large-scale dumping has not occurred north of the Kings Creek Disposal Site or east of the 30th Street Landfill.
Date: January 1, 1995
Creator: Davies, B.E.; Miller, S.F.; McGinnis, L.D.; Daudt, C.R.; Thompson, M.D.; Stefanov, J.E. et al.
Partner: UNT Libraries Government Documents Department

Environmental geophysics: Building E3640 Decommissioning, Aberdeen Proving Ground, Maryland. Interim progress report

Description: Building E3640 is a potentially contaminated site in the Edgewood area of Aberdeen Proving Ground. Noninvasive geophysical survey techniques, including magnetics, EM-31, EM-61, and ground-penetrating radar, were used as part of a sampling and monitoring program prior to decommissioning and dismantling of the building. Complex and large-amplitude anomalies caused by aboveground metal in this area obscure many smaller features produced by subsurface sources. No underground storage tanks were found in the areas surveyed. Major anomalies produced by subsurface sources include the following: EM-61 and EM-31 lineaments caused by a water line extending north from the south fence; a broad positive magnetic anomaly caused by magnetic fill north of the material and drum storage area and northeast of E3640; a 30-ft-wide band of EM-31 anomalies extending from the front gate to the southeast comer of E3640 and a coincident EM-61 anomaly produced by buried utilities; ground-penetrating radar images along three lines extending from a sump at the northeast comer of E3640 to the eastern fence; and EM-61, EM-31, and magnetic anomalies caused by overhead and underground pipes extending south from the north fence. Smaller, unidentified, localized anomalies observed throughout the survey area are also described in this report.
Date: January 1995
Creator: McGinnis, L. D.; Miller, S. F.; Borden, H. M.; Benson, M. A.; Thompson, M. D.; Padar, C. A. et al.
Partner: UNT Libraries Government Documents Department

Salinity and hydrodynamics of the Holocene and upper Pleistocene beneath the Louisiana wetlands from electrical measurements

Description: A conceptual hydrodynamic model in the Holocene and upper Pleistocene beneath the Louisiana wetlands is described in terms of safety distributions. Porewater safety is calculated from electrical measurements, including resistivity soundings, electric logs, and electromagnetic profiling. Electrical measurements support the primary, basin-wide groundwater flow model; however, the data also indicate secondary contributions from expulsion of fluids under geopressure along active growth faults and from original waters of deposition. Expulsion of water from growth faults has been described previously for deeper sections of the Pleistocene, but has not been reported for the Holocene or upper Pleistocene beneath the Louisiana wetlands. Porewater chemistry variations beneath the coastal wetlands are a consequence of the following (in order of importance): (1) environment of deposition; (2) a basin-wide, regional flow system; (3) expulsion from deep-seated growth faults; and (4) pore water extrusion due to compaction. Water chemistry in Holocene clays and muds is influenced primarily by the deposition environment In Pleistocene sands, the chemistry is a function of the other three factors.
Date: June 1, 1995
Creator: McGinnis, L.D.; Thompson, M.D.; Kuecher, G.J.; Wilkey, P.L. & Isaacson, H.R.
Partner: UNT Libraries Government Documents Department

Compressional wave character in gassy, near-surface sediments in southern Louisiana determined from variable frequency cross-well, borehole logging, and surface seismic measurements

Description: Velocity and attenuation data were used to test theoretical equations describing the frequency dependence of compressional wave velocity and attenuation through gas-rich sediments in coastal Louisiana. The cross-well data were augmented with velocities derived from a nearby seismic refraction station using a low-frequency source. Energy at 1 and 3 kHz was successfully transmitted over distances from 3.69 to 30 m; the 5 and 7-kHz data were obtained only at distances up to 20 m. Velocity tomograms were constructed for one borehole pair and covered a depth interval of 10--50 m. Results from the tomographic modeling indicate that gas-induced low velocities are present to depths of greater than 40 m. Analysis of the velocity dispersion suggests that gas-bubble resonance must be greater than 7 kHz, which is above the range of frequencies used in the experiment. Washout of the boreholes at depths above 15 m resulted in a degassed zone containing velocities higher than those indicated in both nearby refraction and reflection surveys. Velocity and attenuation information were obtained for a low-velocity zone centered at a depth of approximately 18 m. Measured attenuations of 1.57, 2.95, and 3.24 dB/m for the 3-, 5-, and 7-kHz signals, respectively, were modeled along with the velocity data using a silt-clay sediment type. Density and porosity data for the model were obtained from the geophysical logs; the bulk and shear moduli were estimated from published relationships. Modeling results indicate that gas bubbles measuring 1 mm in diameter occupy at least 25% to 35% of the pore space.
Date: June 1995
Creator: Thompson, M. D.; McGinnis, L. D.; Wilkey, P. L. & Fasnacht, T.
Partner: UNT Libraries Government Documents Department