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At least 55 records · Page 3Linked to original sources

Nutrient enrichment in wadeable urban streams in the piedmont ecoregion of the southeastern United States

The U.S. Geological Survey (USGS) Southeastern Stream Quality Assessment (SESQA) collected weekly samples for nitrogen and phosphorus in 76 wadeable streams in the urbanized Piedmont ecoregion of the Southeastern United States, during April–June 2014. Total nitrogen (TN) concentrations in excess of EPA guidelines and statistically greater than at reference locations indicated nitrogen-nutrient enrichment in streams draining poultry confined animal feeding operations (CAFO) or urban centers. Nitrate plus nitrite (NO3 + NO2) dominated TN species in urban/CAFO-influenced streams. Streams that drained poultry CAFO and Washington DC had statistically higher NO3 + NO2 concentrations than streams draining Atlanta, Charlotte, Greenville, or Raleigh. In contrast, total phosphorus (TP) concentrations in Atlanta and Washington DC streams statistically were comparable to and lower than, respectively, reference stream concentrations. Over 50% of TP concentrations in Greenville, Charlotte, Raleigh and CAFO-influenced streams exceeded the EPA guideline and reference location mean concentrations, indicating phosphorus-nutrient enrichment. Urban land use, permitted point sources, and soil infiltration metrics best predicted TN exceedances. Elevated TN and NO3 + NO2 concentrations in urban streams during low flow were consistent with reduced in-stream dilution of point-source or groundwater contributions. Urban land use, permitted point sources, and surface runoff metrics best predicted TP exceedances. Elevated TP in CAFO and urban streams during high flow were consistent with non-point sources and particulate transport.

Piedmont Ecoregion

Geologic Map of the Atlin Quadrangle, Southeastern Alaska

This map presents the results of U.S. Geological Survey (USGS) geologic bedrock mapping studies in the mostly glacier covered Atlin 1:250,000-scale quadrangle, northern southeastern Alaska. These studies are part of a long-term systematic effort by the USGS to provide bedrock geologic and mineral-resource information for all of southeastern Alaska, covering all of the Tongass National Forest (including Wilderness Areas) and Glacier Bay National Park and Preserve. Some contributions to this effort are those concerned with southwesternmost part of the region, the Craig and Dixon Entrance quadrangles (Brew, 1994; 1996) and with the Wrangell-Petersburg area (Brew, 1997a-m; Brew and Grybeck, 1997; Brew and Koch, 1997). As shown on the index map (fig. 1), the study area is almost entirely in the northern Coast Mountains adjacent to British Columbia, Canada. No previous geologic map has been published for the area, although Brew and Ford (1985) included a small part of it in a preliminary compilation of the adjoining Juneau quadrangle; and Brew and others (1991a) showed the geology at 1:500,000 scale. Areas mapped nearby in British Columbia and the United States are also shown on figure 1. All of the map area is in the Coast Mountains Complex as defined by Brew and others (1995a). A comprehensive bibliography is available for this and adjacent areas (Brew, 1997n).

Scientific Investigations Map

Final executive summary report; environmental studies, southeastern United States Atlantic Outer Continental Shelf, 1977; geology

Starting in mid 1976 and continuing into 1977 a variety of geological studies were carried out by the U. S. Geological Survey on the southeastern U. S. Atlantic Continental Margin to assess conditions and hazards that might cause or distribute oil spills or other pollutants, or constrain petroleum exploration or development of the area. These detailed investigations were requested and funded by the Bureau of Land Management to carry out its responsibility under the Outer Continental Shelf (OCS) Lands Act of 1969. Because of the energy crisis the decision had been made to lease on the southeastern continental shelf. A variety of studies had to be mounted quickly for input into decisions concerning the environment that would affect or constrain which lease tracks would be offered. The first lease sale, Lease Sale 43, took place in March 1978, and the environmental information on which this lease sale was based came in part from this initial effort and in part from a wide variety of pertinent data assembled from the literature by the Bureau of Land Management's Environmental Assessment Division. The compilation of relevant data for the Environmental Impact Statement for Lease Sale 43 also pointed up deficiencies in environmental knowledge in a number of areas. The Bureau of Land Management's environmental program for the Southeast Atlantic OCS was initiated to fill gaps in the environmental data base and to detect and assess impacts from oil and gas exploration and production.

Florida, North Carolina, South Carolina

Mapping watershed potential to contribute phosphorus from geologic materials to receiving streams, southeastern United States

As part of the southeastern United States SPARROW (SPAtially Referenced Regressions On Watershed attributes) water-quality model implementation, the U.S. Geological Survey created a dataset to characterize the contribution of phosphorus to streams from weathering and erosion of surficial geologic materials. SPARROW provides estimates of total nitrogen and phosphorus loads in surface waters from point and nonpoint sources. The characterization of the contribution of phosphorus from geologic materials is important to help separate the effects of natural or background sources of phosphorus from anthropogenic sources of phosphorus, such as municipal wastewater or agricultural practices. The potential of a watershed to contribute phosphorus from naturally occurring geologic materials to streams was characterized by using geochemical data from bed-sediment samples collected from first-order streams in relatively undisturbed watersheds as part of the multiyear U.S. Geological Survey National Geochemical Survey. The spatial pattern of bed-sediment phosphorus concentration is offered as a tool to represent the best available information at the regional scale. One issue may weaken the use of bed-sediment phosphorus concentration as a surrogate for the potential for geologic materials in the watershed to contribute to instream levels of phosphorus-an unknown part of the variability in bed-sediment phosphorus concentration may be due to the rates of net deposition and processing of phosphorus in the streambed rather than to variability in the potential of the watershed's geologic materials to contribute phosphorus to the stream. Two additional datasets were created to represent the potential of a watershed to contribute phosphorus from geologic materials disturbed by mining activities from active mines and inactive mines.

Alabama, Florida, Georgia, Kentucky, Mississippi,

Dr. Cooper Curtice - Unknown worker in interpreting the Cambrian of Alabama

Cooper Curtice was an assistant to C. D. Walcott from 1883-1886. In 1885, he spent four months, mostly in Alabama, measuring sections of Paleozoic rocks and searching for fossils, mainly in the Cambrian. In 1888, Walcott concurred with foreign authorities that the rocks called Middle Cambrian in North America were Early Cambrian in age and vice versa, requiring a new interpretation of Cambrian strata. Curtice returned to Alabama for geologic investigations in 1892, and again briefly with Walcott in 1895. Since that time Cambrian stratigraphy in the southeastern United States has remained virtually unchanged.

Southeastern Geology