Environmental Baseline Monitoring in the Area of General Crude Oil Department of Energy Pleasant Bayou Number 1, Vol 1 & 3

A program to monitor baseline air and water quality, subsidence, microseismic activity, and noise in the vicinity of the Brazoria County geopressured-geothermal test well, Pleasant Bayou #1 and #2, has been underway since March 1978 (fig. 1). The findings of certain portions of the work, including the results of an initial first-order leveling survey completed by Teledyne Geotronics, a preliminary noise survey completed by Radian Corporation, a preliminary microseismicity survey completed by Teledyne Geotech, and an archeological survey of the site completed by Texas A&M University have been reported earlier and will not be repeated here. The following report contains a description of baseline air and water quality of the test well site, a noise survey, an inventory of microseismic activity including interpretations of the origin of the events, and a discussion of progress in the installation of a liquid tilt meter at the test well site. In addition, the first-order leveling survey recently completed by the National Geodetic Survey is briefly discussed. This survey has allowed the calculation of local baseline subsidence rates. On the basis of analyses of geopressured-geothermal resources by Bebout and others (1975a and b, 1976, 1978), a series of geothermal fairways were recognized within the Frio Formation along the Texas Gulf Coast. From the group of Frio Formation fairways, the Brazoria County fairway was determined to be the most suitable for testing because the permeabilities of the reservoir rocks containing the resource were higher here than the reservoir-rock permeabilities in all other known geothermal fairways in the Texas Gulf Coast. On this basis, the Department of Energy-General Crude Oil Corporation Pleasant Bayou III well was spudded in July 1978.Bureau of Economic Geolog

Sedimentary Facies, Depositional Environments, and Paleosols of the Upper Tertiary Fort Hancock Formation and the Tertiary Quaternary Camp Rice Formation, Hueco Bolson, West Texas

The Hueco Bolson is a segment of the Rio Grande Rift, which formed as a result of late Tertiary Basin and Range deformation. The upper Tertiary Fort Hancock Formation and the upper Tertiary-Quaternary Camp Rice Formation compose the basin fill except in the deepest (western) parts of the bolson. Five lithofacies make up the Fort Hancock Formation: (I) gravel; (II) sand, sandy mud, or sandy silt and gravel; (III) sand, sandy mud, and sandy silt; (IV) clay and sandy clay; and (V) clay, mud, sandy mud, and gypsum. These lithofacies represent the textural gradation from basin margin to basin center of proximal to transitional to distal alluvial fans (lithofacies I through III) to ephemeral lakes (IV) to saline playas (V). In cores from beneath the study area, these same lithofacies are present in a 230-meter-thick (700-ft) upward-fining sequence. The sequence records the lacustrine expansion that occurred over basin-margin alluvial fans as the basin filled. The Fort Hancock Formation is separated from the overlying Camp Rice Formation by a regional unconformity. The unconformity records a period of extensive erosion that marks the integration of the ancestral southern and northern segments of the Rio Grande approximately 2.25 million years ago. Fluvial, lacustrine, and eolian sediments accumulated above the unconformity as the Camp Rice Formation. Five lithofacies also make up the Camp Rice Formation: (1) sand and locally derived gravel, which was deposited by tributaries to the Rio Grande; (2) sand and exotic gravel (derived from north of the study area), which was deposited by a through-flowing stream, the Rio Grande; (3) sand, which was deposited as a dune complex; (4) coarse silt and very fine sand, which was deposited as loess; and (5) clay, sandy clay, and gypsum, which was deposited in ephemeral lakes with central playas.Bureau of Economic Geolog

The glacial geology of eastern Sheridan County, North Dakota

During late Pleistocene time two ice advances affected parts of eastern Sheridan County, North Dakota. The first advance deposited the Burnstad, Streeter and Grace City drifts, and covered the whole county. The second advance deposited the Martin drift and occupied only the northern quarter of the county. The Streeter drift, characterize by dead-ice landforms and nonintegrated drainage, is separated from the Burnstad drift by a large partly collapsed outwash plain on the distal side of a pronounced ground moraine and poorly integrated drainage, is separated from the Streeter drift by the Lincoln Valley and moraine and the Missouri Coteau escarpment. Total ablation of the Grace City ice in this area must have occurred before formation of the Martin end moraine because large portions of outwash from an uncollapsed outwash plain were incorporated into the Martin end moraine north of Lincoln Valley. The Martin drift is characterized by high relief ground moraine, nonintegrated drainage and a slightly sandier lithology than that of the Streeter and Grace City drifts. North of the Martin end moraine several “shear” moraines and small area of dead-ice moraines are present. The ice retreated from Sheridan County less than 18,000 years ago. Several large potential sources of ground water are present in eastern Sheridan County, four large outwash plains each contain large quantities of shallow ground water. The buried channel of the ancient Knife River may also contain large amounts of ground water. Future economic growth of this are will depend partly of effective development of its large ground water resources and to a lesser degree on development of its abundant sand and gravel deposits

Geothermal resources of the Texas Gulf Coast- Environmental concerns arising from the production and disposal of geothermal waters.

Disposal and temporary storage of spent geothermal fluids and surface subsidence and faulting are the major environmental problems that could arise from geopressured geothermal water production. Geopressured geothermal fluids are moderately to highly saline (8,000 to 72,000 parts per million total dissolved solids) and may contain significant amounts of boron (19 to 42 parts per million). Disposal of hot saline geothermal water in the subsurface saline aquifers will present the least hazard to the environment. It is not known, however, whether the disposal of as much as 54,000 m3 (310,000 barrels) of spent fluids per day into saline aquifers at the production site is technically or economically feasible. If saline aquifers adequate for fluid disposal cannot be found, geothermal fluids may have to be disposed of by open watercourses, canals and pipelines to coastal bays on the Gulf of Mexico. Overland flow or temporary storage of geothermal fluids may cause negative environmental impacts. As the result of production of large volumes of geothermal fluid, reservoir pressure declines may cause compaction of sediments within and adjacent to the reservoir. The amount of compaction depends on pressure decline, reservoir thickness, and reservoir compressibility. At present, these parameters can only be estimated. Reservoir compaction may be translated in part to surface subsidence. When differential compaction occurs across a subsurface fault, fault activation may occur and be manifested as differential subsidence across the surface trace of the fault or as an actual rupture of the land surface. The magnitude of environmental impact of subsidence and fault activation varies with current land use; the greatest impact would occur in urban areas, whereas relatively minor impacts would occur in rural, undeveloped agricultural areas. Geothermal resource production facilities on the Gulf Coast of Texas could be subject to a series of natural hazards: (1) hurricane- or storm-induced flooding, (2) winds from tropical storms, (3) coastal erosion, or (4) expansive soils. None of these hazards is generated by geothermal resource production, but each has potential for damaging geothermal production and disposal facilities that could, in turn, result in leakage of hot saline geothermal fluids

Late Cenozoic Geomorphic Evolution of the Texas Panhandle and Northeastern New Mexico: Case Studies of Structural Controls of Regional Drainage Development

Salt dissolution has affected parts of the Upper Permian Salado, Seven Rivers, San Andres, Glorieta, and upper Clear Fork Formations beneath the Pecos River Valley in eastern New Mexico and beneath the Canadian River Valley and the Rolling Plains of the Texas Panhandle. Extensive dissolution of the salts of the Salado and Seven Rivers Formations has also occurred beneath the Southern High Plains. The cumulative thickness of salt lost to dissolution exceeds 150 m (500 ft) along the western, northern, and eastern margins of the Palo Duro Basin. Dissolution and subsidence occurred during the deposition of the Tertiary Ogallala Formation, but Ogallala deposition kept pace with subsidence. Following the end of Ogallala deposition in the late Pliocene, surface subsidence resulted in lacustrine basins along trends of relatively rapid dissolution. Preserved lacustrine sediments contain Blancan faunas, confirming minimum late Pliocene ages for the basins. Continued subsidence along trends of relatively rapid dissolution during the late Tertiary and early Quaternary resulted in a series of basins that diverted many of the streams flowing southeasterly across the Southern High Plains. As a result of subsidence, the headwaters of the ancestral Brazos River were diverted during the middle Pleistocene from a southeasterly drainage through the Portales paleovalley to a southerly drainage through the Pecos Valley. The present-day headwaters of the Canadian River are probably a former tributary of the Pecos-Portales-Brazos system that was diverted to the northeast along a subsidence trend caused by dissolution during the late Pliocene or early Quaternary.Bureau of Economic Geolog

Salt Dissolution: Examples from Beneath the Southern High Plains

Regional salt dissolution and the subsequent collapse of overlying strata have affected substantial parts of the Texas and Oklahoma Panhandles (Gustavson and others, 1980; Johnson, 1981). There are seven salt-bearing units within the Permian System of the Texas Panhandle and eastern New Mexico. With the probable exception of the lower Clear Fork Formation, all the younger salt-bearing units are locally undergoing dissolution. Several lines of evidence support the conclusion that zones of salt dissolution underlie parts of the Southern High Plains, the Rolling Plains, and the Canadian River Breaks (Gustavson and others, 1980, 1982): (1) The major streams draining the region surrounding the Southern High Plains carry high-solute loads, indicating that dissolution is active. For example, the Prairie Dog Town Fork of the Red River carries a mean annual solute load of 1,003.4 x 103 tons of dissolved solids per year, including 425.3 x 103 tons of chloride per year (U.S. Geological Survey, 1969-1977). Brine springs, salt springs, and salt pans appear along this and other stream valleys. (2) The abrupt loss of salt sequences between relatively closely spaced oil and gas exploration wells indicates salt dissolution and not facies change. Structural collapse of overlying strata is evident in the wells where salt is missing (fig. 1). (3) Brecciated zones, fractures with slickensides, extension fractures filled with gypsum, and insoluble residues composed of mud, anhydrite, or dolomite overlie the uppermost salts in cores from the DOE-Gruy Federal No. 1 Rex H. White well in Randall County, the DOE-Gruy Federal No. 1 D. N. Grabbe well and the Stone and Webster Engineering Corp. No. 1 Zeeck and No. 1 Harmon wells in Swisher County, the Stone and Webster Engineering Corp. No. 1 Sawyer well in Donley County, the Stone and Webster Engineering Corp. No. 1 G. Friemel, No. 1 J. Friemel and No. 1 Deten wells in Deaf Smith County, and the Stone and Webster Engineering Corp. No. Mansfield well in Oldham County. (4) Numerous sinkholes and closed depressions (dolines) have formed recently in the Rolling Plains and are interpreted to be the result of dissolution and subsidence (Gustavson and others, 1982). (5) Permian outcrops both east of the Caprock Escarpment and in the Canadian River valley display folds, systems of extension fractures, breccia beds, and remnants of caverns. Structural, stratigraphic, core, and geomorphic evidence suggest that salt dissolution was active beneath the Southern High Plains during the Pliocene and probably the Pleistocene. Two case studies are presented, one describing evidence for dissolution in eastern Deaf Smith County and one describing evidence for dissolution in eastern Swisher County. Using core and stratigraphic data interpretations of the geology in the two case study areas can be extrapolated to the preferred sites in Deaf Smith and Swisher Counties. In each case, it is both reasonable and conservative to infer that dissolution and subsidence of overlying strata occurred during the Pliocene and probably during the Pleistocene.Bureau of Economic Geolog

Summary Hydrogeologic Assessment U.S. Department of Energy Pantex Plant, Carson County, Texas

In 1990, the Bureau of Economic Geology (BEG) and the Department of Geological Sciences (DOGS) at The University of Texas at Austin and the Water Resources Center (WRC) at Texas Tech University began a five-year program, funded by the Department of Energy (DOE) through the Governor's Office of the State of Texas, to characterize the geohydrology of Pantex Plant. The purpose of this work, which is summarized in this report, was to provide data and information that would assist in the remediation of contaminated sites at Pantex and support the State of Texas in its review of the Department of Energy's (DOE's) remediation program. The results of this investigation describe the physical setting and heterogeneities that control movement and distribution of contaminants and the processes that affect rates and fate of contaminants. The fate and distribution of contaminants, the selection and application of appropriate remediation approaches, the evaluation of the effectiveness of remediation technologies, and the proper monitoring of the affected environment all depend on knowledge of the controls and rates of active processes at Pantex Plant.Bureau of Economic Geolog

Environmental Baseline Monitoring in the Area of General Crude Oil- Department of Energy Pleasant Bayou Number 2 A Geopressured Geothermal Test well

A program to monitor baseline air and water quality, subsidence, microseismic activity, and noise in the vicinity of the Brazoria County geopressured geothermal test wells, Pleasant Bayou III and II, has been underway since March 1978 (fig. 1). The findings of certain parts of the work, including the results of an initial first-order leveling survey completed by Teledyne Geotronics, a preliminary noise survey completed by Radian Corporation, a preliminary microseismicity survey completed by Teledyne Geotech, and an archeological survey of the site completed by Texas A&M University, have been reported earlier and will not be repeated here. The initial report on environmental baseline monitoring at the test well contained descriptions of baseline air and water quality, a noise survey, an inventory of microseismic activity, and a discussion of the installation of a liquid tilt meter (Gustavson, 1979). The following report continues the description of baseline air and water quality of the test well site, includes an inventory of microseismic activity during 1979 with interpretations of the origin of the events, and discusses the installation and monitoring of a liquid tilt meter at the test well site. In addition, a brief description of flooding at the test site is presented.Bureau of Economic Geolog

Regional Strucutal Cross Sections, Mid-Permian to Quaternary Strata, Texas Panhandle and Eastern New Mexico

The Palo Duro and Dalhart Basins of the Texas Panhandle and eastern New Mexico contain bedded Permian salts of sufficient thickness and depth to be considered potential sites for long-term storage and isolation of high-level nuclear waste. Salt (primarily halite) is a desirable host rock because of its low permeability, high thermal conductivity, low moisture content, and high gamma-ray shielding properties (Johnson, 1976b). A major concern that must be addressed if nuclear waste is to be stored in the Texas Panhandle is the long-term integrity of the bedded-salt host rock. Areas where salt has been removed by dissolution have been identified beneath the Southern High Plains, along the eastern and western escarpments of the Southern High Plains, and along the Canadian River valley (Gustavson and others, 1980b; Presley, 1980a, 1980b). Region I cross sections of mid-Permian to Quaternary strata in the Texas Panhandle and eastern New Mexico illustrate lithologic and structural relations that are interpreted to have resulted from the regional dissolution of salt and the collapse of overlying strata. The cross sections were constructed using gamma-ray logs, sample logs, and surface geologic maps (Handford, 1980a; McGillis, 1980). Gamma-ray logs are shown on the cross sections because they best demonstrate variations in evaporite strata. Figure 1 is an index map depicting the locations of the cross sections. Stratigraphic nomenclature used on the cross sections is given in table 1.Bureau of Economic Geolog