Whole body and liver analyses indicated that wintering redheads (Aythya americana; n = 70) in coastal Louisiana (one site) and Texas (two sites) were relatively free of contamination with common trace elements, organochlorines, and hydrocarbons. Most trace elements, including As, Cr, Hg, Mg, Mn, Ni, Pb, Se, Sr, and Zn, were within background concentrations in livers; levels of B, Cd, Cu, and Fe were elevated in some specimens. Only one organochlorine, DDE, was detected in redhead carcasses, but its concentration was below reported toxic levels in waterfowl. Body burdens of aliphatic and aromatic hydrocarbons were generally low, but levels of pristane, total hydrocarbons, and the ratios of phytane:n-octadecane and pristane:n-heptadecane were indicative of possible chronic exposure to petroleum. Based on brain cholinesterase assays, redheads were not recently exposed to organophosphorous or carbamate pesticides. Of 30 elements or compounds tested for seasonal differences, only Se increased from early to late winter at one of the three sites. Eight of 57 contaminants differed among the three sites; no sex or age differences were found.

Louisiana, Texas↗

USGS1990

Quaternary geologic map of the White Lake 4° x 6° quadrangle, United States

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1990. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the White Lake 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Louisiana, Texas↗

USGS1987

Development of ground-water resources in the Orange County area, Texas and Louisiana, 1980-Spring of 1985

This report updates ground-water information pertaining to the lower unit of the Chicot aquifer in the Orange County area, Texas and Louisiana. The period of data collection was from 1980 to the spring of 1985. Some data collected prior to 1980 are presented to establish long-term trends and relations. The lower unit of the Chicot aquifer, which consists of sediments of Pleistocene age, is confined and underlies all of the study area. The base of the aquifer ranges from about 400 feet below National Geodetic Vertical Datum of 1929 in the northwestern part of the county to about 1,000 feet below National Geodetic Vertical Datum of 1929 in the southeastern part. The lower unit of the Chicot aquifer is the main source of freshwater for several cities, communities, industries, housing subdivisions, and individual homeowners in Orange County. The total pumpage from the lower unit of the Chicot aquifer in Orange County decreased from a historical maximum of 23.1 million gallons per day during 1972 to an estimated 15.2 million gallons per day during 1984. The average industrial pumpage during 1980-84, 10.5 million gallons per day, decreased substantially when compared to 1963-79, when an average of 15.6 million gallons per day was withdrawn. This is in contrast to municipal pumpage that increased from an average withdrawal of 5.3 million gallons per day during 1963-79 to 7.3 million gallons per day during 1980-84. The use of surface water decreased from a peak withdrawal of 58.1 million gallons per day during 1981 to 41.4 million gallons per day during 1984. From the spring of 1980 to the spring of 1985, water levels in the lower unit of the Chicot aquifer in the Orange County area ranged from rises of as much as 14 feet to declines of as much as about 3 feet. Water levels rose throughout most of the area. The greatest rise in water levels occurred in and near the city of Orange, whereas the greatest decline occurred northwest of Vidor. Most of the water in the lower unit of the Chicot aquifer is fresh, but the water quality can vary greatly within short distances. Chloride concentrations determined during 1980-84 ranged from 10 to 1,700 milligrams per liter. The larger chloride concentrations were measured where salinewater coning and updip migration are occurring. In general, chloride concentrations remained constant during 1980-84. A relation exists between chloride concentrations and specific conductance. It was determined that chloride concentrations (milligrams per liter) generally can be estimated by multiplying specific-conductance values (microsiemens per centimeter at 25 °Celsius) by 0.29 when the specific conductance is between 500 and 5,600 microsiemens per centimeter at 25 °Celsius.

Louisiana, Texas↗

USGS1982

Development of ground-water resources in Orange County, Texas, and adjacent areas in Texas and Louisiana, 1971-80

Pumpage in Orange County from the lower unit of the Chicot aquifer averaged 21.2 million gallons per day (0.93 cubic meter per second) and pumpage from the upper unit of the Chicot averaged about 2 million gallons per day (0.088 cubic meter per second) from 1971-79. Annual pumpage increased in municipal areas and decreased in industrial areas with little net change in total annual pumpage during the report period. The major water-bearing unit in the study area is the Chicot aquifer, which overlies the Evangeline aquifer. The Evangeline aquifer is undeveloped in Orange County, but is developed at Evadale in Jasper County, Texas, and at Silsbee in Hardin County, Texas. Both aquifers consist of unconsolidated and discontinuous layers of sand and clay that gently dip toward the Gulf of Mexico. Water levels in Orange County tended to stabilize or rise in areas where ground-water withdrawals decreased. Elsewhere in Orange County, most water levels continued to decline, generally at a slower rate than before 1971. Bench-mark elevations determined during 1973 show regional land-surface subsidence from 1918-73, generally attributed to ground-water development, to be less than 0.5 foot (0.15 meter). Locally, subsidence due to production of oil, gas, saltwater, or sulfur was about 15 feet (4.6 meters) at Spindletop Dome, Jefferson County, Texas, and as much as 3 feet (1.0 meter) near Port Acres gas field, Jefferson County, Texas. Although saltwater encroachment is evident in parts of southern Orange County, the encroachment is not expected to be detrimental if the ground-water pumping remains stable and the projected increase in demands for water is met with surface-water supplies.

Louisiana, Texas↗

USGS1981

234U and 238U concentration in brine from geopressured aquifers of the northern Gulf of Mexico basin

The 234 U and 238 U concentration in brine from six Gulf Coast geopressured aquifers has been determined. The results reveal very low uranium concentrations (from 0.003 to 0.03 μg/l) and uranium activity ratios slightly greater than unity (from 1.06 to 1.62). Reducing conditions within the aquifers are responsible for the low uranium concentrations. The uranium activity ratios observed are well below those calculated using theoretical considerations of alpha-particle recoil effects. This can be explained by interference with alpha-recoil nuclides entering the liquid phase as a result of quartz overgrowths on sand grains and high-temperature re-equilibration that tends to minimize the effects of the alpha-recoil process. The fact that the uranium activity ratios of the brines are slightly greater than unity instead of the equilibrium value of 1.000 indicates that either the alpha particle recoil blocking and re-equlibration effects are not complete or that another process is operative that enriches the fluid in excess 234 U by selectively removing uranium from radiation induced damage sites in the mineral (sand grain) matrix.

Louisiana, Texas↗

USGS1981

Estimated oil and gas reserves, Gulf of Mexico outer continental shelf and continental slope, December 31, 1980

No abstract available.

Louisiana, Texas↗

USGS1979

Elevations and discharges produced by a simulated flood wave on the lower Sabine River, Louisiana and Texas, caused by a theoretical dam failure

The Toledo Bend Reservoir is located on the lower Sabine River between Louisiana and Texas. The objective of this study was to calculate the flood wave that would result from the theoretical failure of 25 percent of Toledo Bend Dam and route the wave downstream to Orange, Tex. Computations assumed failure (1) at the peak of the 100-year flood when discharge of the Sabine River would be 102,000 cubic feet per second and (2) when the average discharge would be 10,000 cubic feet per second. Two techniques were used in the dam-break model. The method of characteristics was used to propagate the shock wave after the dam fails. The linear implicit finite-difference solution was used to route the flood wave after the shock wave has dissipated. The magnitude of the flood was determined for sites near Burkeville, Bon Wier, Ruliff, and Orange, Tex., along the lower Sabine River. For these sites, respectively, the following peak elevations were calculated: 119, 82, 31, and 13 feet for the 100-year flood and 110, 75, 27, and 9 feet for the average discharge.

Louisiana, Texas↗

USGS1978

Evaluation of methodology used in ecological characterization of the Chenier Plain

No abstract available.

Louisiana, Texas↗

USGS1977

The decline of brown pelicans on the Louisiana and Texas Gulf Coast

Before 1920, native populations of brown pelicans (Pelecanus occidentalis carolinensis) were estimated at 50,000 to 85,000 birds in Louisiana and 5,000 in Texas. By 1958, brown pelicans had vanished from two wintering areas in each state, and wintering and breeding birds disappeared from additional areas between 1959 and 1961. By 1963, the disappearance of the brown pelican from Louisiana was complete, and in Texas only about 100 birds were observed annually. Mortality before 1939, particularly in Texas, was attributed mostly to hunters and fishermen. Losses in both states were attributed to hurricanes, disease, and extended periods of freezing weather. Pesticides may also have contributed significantly. Widespread endrin-caused fish mortality was documented between 1958 and 1964 in Louisiana. Pelicans undoubtedly were exposed to endrine through eating the fish. Significant levels of DDE were found in Texas fishes in the late 1960's. DDE residues in pelican eggs were high enough to be responsible for nesting failure. Shell thinning averaged 10% in Texas pelican eggs collected in 1970, 1972, and 1974, but in earlier years greater thinning was associated with the collapse and loss of eggs. Poor reproductive success during recent years was believed due to (1) failure of many adult pelicans to nest and (2) a high rate of nestling mortality in the few pairs that did nest and hatch young. The remnant population of brown pelicans on the Texas Coast will disappear unless reproductive success improves, because recruitment is presently insufficient to offset mortality.

Louisiana, Texas↗

USGS1974

Hydrogeologic aspects of structural deformation in the northern Gulf of Mexico Basin

The first Earth Resources Technology Satellite (ERTS-1), launched by the National Aeronautics and Space Administration in.July 1972, is providing valuable data for investigations of the most inaccessible and hostile regions of the Earth the Arctic and Antarctic. ERTS images and map products derived from them offer a whole new dimension in source material for multidiscipline investigations in the earth sciences. For the first time scientists can view synoptic, repetitive scenes of the polar regions in four spectral bands. Ongoing experiments funded by NASA and conducted in the U.S. Geological Survey have demonstrated the feasibility of revising coastlines on maps of Antarctica, detected gross changes in the northern limits of the three largest ice shelves in the world, and led to the discovery of uncharted mountain ranges.

Louisiana, Texas↗

USGS1973

Pen-reared fulvous tree ducks used in movement studies of wild populations

To obtain movement data on wild fulvous tree ducks ( Dendrocygna bicolor ) 165 immature pen-reared fulvous tree ducks were color-marked and released in three southeast Texas counties in July October 1969/70. Nine (5 percent) of the marked birds were recovered from 3 days to 9 months after release, and an additional 15 birds provided sight records. Many released birds apparently became integrated into the wild population; all of those observed were with wild flocks. Six birds were recovered over 50 miles from the release sites. Four released in late July to mid-September had moved eastward and two went southward in September or later. Five were still in the Texas-Louisiana rice belt (three in late November). The sixth bird was recovered in October in Veracruz, which supports the assumption that U.S. Gulf Coast nesting populations winter in southern Mexico.

Louisiana, Texas↗