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Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

1991

Earth Sciences

Old Dominion University

Articles 1 - 4 of 4

Full-Text Articles in Physical Sciences and Mathematics

The Geomorphology Of Alluvial Fan Deposits On The West Flank Of The Blue Ridge, Augusta County, Virginia, Debra Lynn Duffy Oct 1991

The Geomorphology Of Alluvial Fan Deposits On The West Flank Of The Blue Ridge, Augusta County, Virginia, Debra Lynn Duffy

OES Theses and Dissertations

Large coalescing alluvial fans mantle the carbonate and shale formations west of the Blue Ridge mountains near Stuarts Draft, Virginia. Fan sediments are predominantly boulder and cobble gravels derived from the Antietam Quartzite, The fan complex consists of three alluvial units of significantly different ages. The surface of each fan unit was mapped using relative geomorphic position, soil color, clay content and thickness of Bt horizons, clast weathering, and degree of removal of depositional surfaces by stream incision. A five-category quartzite clast weathering scale developed for this study was very effective as a measure to distinguish map units. Stratigraphic data …

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Lava-Seawater Interactions At Shallow-Water Submarine Lava Flows, Francis J. Sansone, Joseph A. Resing, Gordon W. Tribble, Peter N. Sedwick, Kevin M. Kelly, Ken Hon Sep 1991

Lava-Seawater Interactions At Shallow-Water Submarine Lava Flows, Francis J. Sansone, Joseph A. Resing, Gordon W. Tribble, Peter N. Sedwick, Kevin M. Kelly, Ken Hon

OES Faculty Publications

Hydrothermal plumes associated with nearshore lava flows from Kilauea Volcano, Hawaii were studied on five occasions during 1989-1990 to address the current lack of data on direct lava-seawater interactions. The following enrichments were found in the sea-surface hydrothermal plumes above the active underwater lava flows: H2, 15,000x ambient seawater concentrations; Mn, 250x; and Si, 20x. Water temperatures reached 46°C. Lower concentrations and temperatures were observed in the plumes with increasing distance from shore, with H2, Si, and Mn concentrations linearly related to seawater temperature. Unlike deep sea spreading center hydrothermal plumes, no CH4 enrichment was …

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The Kinetics Of Organic Matter Mineralization In Anoxic Marine Sediments, David J. Burdige Jan 1991

The Kinetics Of Organic Matter Mineralization In Anoxic Marine Sediments, David J. Burdige

OES Faculty Publications

The kinetics of sulfate reduction and inorganic nutrient production (ΣCO2, ammonium, and phosphate) were examined in the sediments at five sites in the southern Chesapeake Bay, using long term (> 200 d) sediment decomposition experiments. Average first order rate constants for these processes (at 25oC) decreased from 8.2 to 3.7 yr-1 in the surface sediments (0-2 cm), to 2.1 to 0.2 yr-1 at 12-14 cm. The C/N and C/P ratios of the organic matter undergoing decomposition also increased with depth at these sites. Taken together, these results indicate that the reactivity of the organic matter …

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A Geophysical And Geological Study Of The Farmville Triassic Basin, Charles G. James Jr. Jan 1991

A Geophysical And Geological Study Of The Farmville Triassic Basin, Charles G. James Jr.

OES Theses and Dissertations

The Farmville basin is one of many Triassic basins which are found along the eastern coast of North America, and is the largest of the central string of basins in Virginia. Meta-volcanic and metasedimentary rocks of the Chopawamsic Formation, as well as felsic intrusives are the primary lithologies surrounding the basin. A detailed gravity survey was conducted along six roads that trend approximately NW-SE, across the basin. Geologic, gravity, magnetic, and radiometric data were used to develop a kinematic model. Gravity anomalies were isolated using two-dimensional harmonic analysis methods to isolate the local, and regional anomalies. This analysis indicates that …

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