Florence Bascom Geoscience Center

Publications

Filter Total Items: 533
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Year Published: 2020

40Ar/39Ar and U-Pb SIMS zircon ages of Ediacaran dikes from the Arabian-Nubian Shield of south Jordan

A spectacular feature of the Arabian-Nubian Shield (ANS) is the abundance of well-exposed and extensive Neoproterozoic dike swarms of multiple generations. These dikes are generally categorized into metamorphosed and unmetamorphosed post-orogenic dike swarms. The unmetamorphosed dikes in the northern ANS can be grouped into an old and young...

Ghanem, Hind; McAleer, Ryan J.; Jarrar, Ghaleb; Al Hseinat, Mu'ayyad; Whitehouse, Martin

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Year Published: 2020

Geology of the Trout Rock caves (Hamilton Cave, Trout Cave, New Trout Cave) in Pendleton County, West Virginia (USA), and implications regarding the origin of maze caves

The Trout Rock caves (Hamilton Cave, Trout Cave, New Trout Cave) are located in a hill named Cave Knob that overlooks the South Branch of the Potomac River in Pendleton County, West Virginia (U.S.A). The geologic structure of this hill is a northeasttrending anticline, and the caves are located at different elevations primarily along the contact...

Swezey, Christopher S.; Brent, Emily L

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Year Published: 2020

Foreward: Geology Field Trips in and around the U.S. Capital

The first annual meeting of the Geological Society of America (GSA) was held in 1888 in Ithaca, New York (Fairchild, 1932), but official Sections of GSA formed much later. During the spring of 1949, a symposium in Knoxville, Tennessee, on mineral resources of the southeastern United States became the catalyst for the creation of the Southeastern...

Swezey, Christopher S.; Carter, Mark W.

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Year Published: 2020

Mapping the extent and methods of small-scale emerald mining in the Panjshir Valley, Afghanistan

Emerald mining in the Panjshir Valley, Afghanistan, has occurred for thousands of years, yet few records exist documenting the detailed spatial extent, techniques, or productivity of small-scale miners. This study proposes new methods to map and monitor the extent and changes in small-scale mining in remote and inaccessible terrain by integrating...

DeWitt, Jessica D.; Chirico, Peter G.; O'Pry, Kelsey L.; Bergstresser, Sarah E.

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Year Published: 2020

Geochronologic age constraints on tectonostratigraphic units of the central Virginia Piedmont, USA

New geologic mapping coupled with uranium-lead (U-Pb) zircon geochronology (sensitive high-resolution ion microprobe-reverse geometry [SHRIMP-RG] and laser ablation-inductively coupled plasma-mass spectrometry [LA-ICP-MS]) analyses of 10 samples, provides new constraints on the tectonostratigraphic framework of the central Virginia Piedmont....

Carter, Mark W.; McAleer, Ryan J.; Holm-Denoma, Christopher S.; Spears, David B.; Regan, Sean P.; Burton, William C.; Evans, Nick H.
Carter, M.W., McAleer, R.J., Holm-Denoma, C.S., Spears, D.B., Regan, S.P., Burton, W.C., and Evans, N.H., 2020, Geochronologic age constraints on tectonostratigraphic units of the central Virginia Piedmont, USA: U.S. Geological Survey Professional Paper 1861, 28 p., https://doi.org/10.3133/pp1861.

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Year Published: 2020

Carbon release through abrupt permafrost thaw

The permafrost zone is expected to be a substantial carbon source to the atmosphere, yet large-scale models currently only simulate gradual changes in seasonally thawed soil. Abrupt thaw will probably occur in <20% of the permafrost zone but could affect half of permafrost carbon through collapsing ground, rapid erosion and landslides. Here, we...

Turetsky, Merritt R.; Abbott, Benjamin W.; Jones, Miriam C.; Walter Anthony, Katey; Olefeldt, David; Schuur, Edward A.G.; Grosse, Guido; Kuhry, Peter; Hugelius, Gustaf; Koven, Charles; Lawrence, David M.; Gibson, Carolyn; Sannel, A. Britta K.; McGuire, A.D.

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Year Published: 2020

Estimating late 19th century hydrology in the Greater Everglades Ecosystem: An integration of paleoecologic data and models

Determining hydrologic conditions prior to instrumental records is a challenge for restoration of freshwater ecosystems worldwide. Paleoecologic data provide this information on past conditions and when these data are used to adjust hydrologic models, allow conditions to be hindcast that may not be directly estimated from the paleo-data alone. In...

Marshall, Frank E.; Bernhardt, Christopher E.; Wingard, G. Lynn

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Year Published: 2020

Impacts of Hurricane Irma on Florida Bay Islands, Everglades National Park, U.S.A.

Hurricane Irma made landfall in south Florida, USA, on September 10, 2017 as a category 4 storm. In January 2018, fieldwork was conducted on four previously (2014) sampled islands in Florida Bay, Everglades National Park to examine changes between 2014 and 2018. The objectives were to determine if the net impact of the storm was gain or loss of...

Wingard, G. Lynn; Bergstresser, Sarah E.; Stackhouse, Bethany; Jones, Miriam; Marot, Marci E.; Hoefke, Kristen; Daniels, Andre; Keller, Katherine

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Year Published: 2020

Quaternary eolian dunes and sand sheets in inland locations of the Atlantic Coastal Plain Province, USA

Quaternary eolian dunes and sand sheets that are stabilized by vegetation are present throughout many inland locations of the Atlantic Coastal Plain province (USA). These locations include river valleys, the Carolina Sandhills region, adjacent to Carolina Bays, and upland areas of the northern coastal plain. The eolian dunes are primarily...

Swezey, Christopher S.

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Year Published: 2019

Preliminary bedrock geologic map of the Lahore 7.5-minute quadrangle, Orange, Spotsylvania, and Louisa Counties, Virginia

IntroductionBedrock geologic mapping of the Lahore, Va., 7.5-minute quadrangle was completed as part of a broader project, undertaken jointly between the U.S. Geological Survey, the Virginia Division of Geology and Mineral Resources, and other Federal and State agencies to better understand the causative mechanisms of the magnitude-5.8 (M5.8)...

Burton, William C.
Burton, W.C., 2019, Preliminary bedrock geologic map of the Lahore 7.5-minute quadrangle, Orange, Spotsylvania, and Louisa Counties, Virginia: U.S. Geological Survey Open-File Report 2019–1110, 1 sheet, scale 1:24,000, https://doi.org/10.3133/ofr20191110.

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Year Published: 2019

Cross section of the North Carolina coastal plain from Enfield through Cape Hatteras

IntroductionThe Atlantic Coastal Plain, the southeasternmost physiographic province in the United States, is underlain by strata that regionally dip gently eastward and gradually thicken toward the Atlantic Ocean basin. These strata, ranging in age from Middle Jurassic to Holocene, accumulated along the eastern margin of North America after the...

Weems, Robert E.; Self-Trail, Jean M.; Edwards, Lucy E.
Weems, R.E., Self-Trail, J.M., and Edwards L.E., 2019, Cross section of the North Carolina coastal plain from Enfield through Cape Hatteras: U.S. Geological Survey Open-File Report 2019–1145, 2 sheets, https://doi.org/10.3133/ofr20191145.

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Year Published: 2019

Geochemistry and geophysics of iron oxide-apatite deposits and associated waste piles with implications for potential rare earth element resources from ore and historic mine waste in the eastern Adirondack Highlands, New York, USA

The iron oxide-apatite (IOA) deposits of the eastern Adirondack Highlands, New York, are historical high-grade magnetite mines that contain variable concentrations of rare earth element (REE)-bearing apatite crystals. The majority of the deposits are hosted within sodically altered Lyon Mountain granite gneiss, although some deposits occur within...

Taylor, Ryan; Shah, Anjana K.; Walsh, Gregory J.; Taylor, Cliff D.