Geology topics

Joe T. Smith

Publications and source records attributed to Joe T. Smith.

5 recordsLinked to original sources

USGS2005

Evaluating lek occupancy of greater sage-grouse in relation to landscape cultivation in the Dakotas

Greater Sage-Grouse (Centrocercus urophasianus) have been declining in many states and provinces of North America, and North and South Dakota hold no exception to these declines. We studied effects of cultivated land on Greater Sage-Grouse lek abandonment in North and South Dakota. Landscape-level data were assessed using satellite imagery within a geographic information system. Comparisons were made of 1972-1976 and 1999-2000 percent cultivated and noncultivated land. These comparisons were made between land uses surrounding active leks versus inactive leks, active leks versus random locations, and abandoned regions versus active regions. The 1999-2000 imagery illustrated that percent cultivated land was greater near abandoned leks (4-km buffers) than near active leks in North Dakota or random sites, but this did not hold true in South Dakota. Comparison of an extensive region of abandoned leks with a region of active leks in North Dakota illustrated a similar increase as well as dispersion of cultivation within the abandoned region. However, 1972-1976 imagery revealed that this relationship between percentage of cultivated land and lek activity in North Dakota has been static over the last 30 years. Thus, if the decline of Greater Sage-Grouse is the result of cultivated land infringements, it occurred prior to 1972 in North Dakota.

Western North American Naturalist↗

USGS2004

Achieving environmentally relevant organochlorine pesticide concentrations in eggs through maternal exposure in Alligator mississippiensis

Alligator mississippiensis eggs from organochlorine pesticide (OCP) contaminated sites in Florida exhibit high rates of embryonic mortality compared to reference sites (p<0.05). The objective of the present study was to use captive adult alligators to test the hypotheses that maternal exposure to OCPs results in increased OCP concentrations in eggs, and that increased exposure is associated with increased embryonic mortality. A total of 24 adult alligators (8 males and 16 females) were housed in eight pens. Eight females in four pens were dosed with a mixture of p,p'-DDE, toxaphene, dieldrin, and chlordane at a rate of 0.2 ? 0.01 mg/kg/day for 274 ? 8 days. Treated females produced eggs containing higher OCP concentrations (12,814 ? 813 ng/g yolk) than controls (38 ? 4 ng/g yolk). Eggs of treated females exhibited decreased viability (13 ? 22%) as compared to controls (45 ? 20%). Results indicated that 0.6% of administered OCPs were maternally transferred to the eggs of American alligators, and that maternal exposure is associated with decreased egg/embryo viability in this species.

Marine Environmental Research↗

USGS1990

Relative inactivity during the last 140,000 years of a portion of the La Paz fault, southern Baja California Sur, Mexico

Uranium-series dating of corals overlying the undeformed Punta Coyote gravels indicates that the underlying La Paz fault zone has been relatively inactive in this part of the Baja California peninsula during the last 140,000 years, and possibly for a significantly longer period. However, Holocene seismic activities along extensions of the fault zone north of Cabo San Lucas suggest potential seismic hazards for the city of La Paz (population 200,000), which lies about 6 km from the fault. ?? 1990 Springer-Verlag New York Inc.

Environmental Geology and Water Sciences↗

USGS1978

Ground-water data for the Salt Basin, Eagle Flat, Red Light Draw, Green River Valley, and Presidio Bolson in westernmost Texas

From October 1971 through October 1974, the U.S. Geological Survey collected ground-water data in the basins in Texas west of the Pecos River drainage area and northwest of the Big Bend country. The basins included are, from east to west: The Presidio Bolson; the Salt Basin; Green River Valley, Eagle Flat, and Red Light Draw. These data, which were collected in cooperation with the Texas Department of Water Resources (formerly Texas Water Development Board), will provide information for a continuing assessment of water availability within the State. The data-collection program consisted of an inventory of all major irrigation, municipal-supply, and industrial wells; selected stock and domestic wells; and selected springs. Water samples were collected from representative wells and springs for chemical analyses. These data, together with data from geophysical surveys and test drilling, will be used to prepare a report on the availability of ground water in the basins of westernmost Texas. Data collected prior to this study are contained in the reports listed in the selected references. The well-numbering system is shown on figure 1, and the locations of the wells, test holes, and springs are shown on figures 2-8. The records of wells and springs are given in table 1, and the water levels in selected observation wells in the Salt Basin are given in table2. The chemical analyses of water samples from selected wells, test holes, and springs are given in table 3.

Texas↗

USGS1972

An evaluation of the use of drillers' logs in lithologic studies of the Ogallala Formation of the southern high plains of Texas, progress report, 1970-71

Logs made by water-well drillers were analyzed in conjunction with test-hole drilling and geophysical logging to evaluate usefulness of the driller's log in delineating areas that would be suitable for artificial recharge of the Ogallala Formation. This preliminary study indicates that lack of detailed and accurate information in many drillers' logs prevents their use as a reliable source of lithologic information. For many applications, such as evaluation of potential areas for artificial recharge, the value of more complete and more accurate information will be readily apparent as these applications become more widespread. More effort will be required in collecting lithologic information as part of the drilling operations.

Texas↗