Florence Bascom Geoscience Center

Publications

Filter Total Items: 519
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Year Published: 2020

Sediment dynamics and implications for management: State of the science from long‐term research in the Chesapeake Bay watershed, USA

This review aims to synthesize the current knowledge of sediment dynamics using insights from long‐term research conducted in the watershed draining to the Chesapeake Bay, the largest estuary in the U.S., to inform management actions to restore the estuary and its watershed. The sediment dynamics of the Chesapeake are typical of many impaired...

Noe, Gregory B.; Cashman, Matthew J.; Skalak, Katherine; Gellis, Allen; Hopkins, Kristina G.; Moyer, Douglas; Webber, James; Benthem, Adam; Maloney, Kelly O.; Brakebill, John; Sekellick, Andrew; Langland, Michael J.; Zhang, Qian; Shenk, Gary Wynee; Keisman, Jennifer L.D.; Hupp, Cliff R.

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Year Published: 2020

Evaluating elevation change thresholds between structure-from-motion DEMs derived from historical aerial photos and 3DEP LiDAR data

This study created digital terrain models (DTMs) from historical aerial images using Structure from Motion (SfM) for a variety of image dates, resolutions, and photo scales. Accuracy assessments were performed on the SfM DTMs, and they were compared to the United States Geological Survey’s three-dimensional digital elevation program (3DEP) light...

Chirico, Peter; DeWitt, Jessica D.; Bergstresser, Sarah E.

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Year Published: 2020

Major-element compositional data and thermal data for drill core from Kīlauea Iki lava lake, plus analyses of glasses from scoria of the 1959 summit eruption of Kīlauea Volcano, Hawaii

This report presents electron microprobe data on glasses and selected crystalline phases from Kīlauea Iki lava lake and glasses from the 1959 summit eruption of Kīlauea Volcano, Hawaii. Some of these data have been published previously, but the complete set has not been published before. In addition, this report includes electron microprobe data...

Helz, Rosalind Tuthill
Helz, R.T., 2020, Major-element compositional data and thermal data for drill core from Kīlauea Iki lava lake, plus analyses of glasses from scoria of the 1959 summit eruption of Kīlauea Volcano, Hawaii: U.S. Geological Survey Open-File Report 2020–1012, 48 p., https://doi.org/10.3133/ofr20201012.

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Year Published: 2020

Bedrock geologic map of the Mount Ascutney 7.5- x 15-minute quadrangle, Windsor County, Vermont, and Sullivan County, New Hampshire

The bedrock geology of the Mount Ascutney 7.5- x 15-minute quadrangle consists of highly deformed and metamorphosed Mesoproterozoic through Devonian metasedimentary and meta-igneous rocks intruded by rocks of the Mesozoic White Mountain Igneous Suite. In the west, Mesoproterozoic gneisses of the Mount Holly Complex are the oldest rocks and form...

Walsh, Gregory J.; Valley, Peter M.; Thompson, Peter J.; Ratcliffe, Nicholas M.; Proctor, Brooks P.; Sicard, Karri R.
Walsh, G.J., Valley, P.M., Thompson, P.J., Ratcliffe, N.M., Proctor, B.P., and Sicard, K.R., 2020, Bedrock geologic map of the Mount Ascutney 7.5- x 15-minute quadrangle, Windsor County, Vermont, and Sullivan County, New Hampshire (ver. 1.1, April 2020): U.S. Geological Survey Scientific Investigations Map 3440, 2 sheets, scale 1:24,000, https://doi.org/10.3133/sim3440.

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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; O'Pry, Kelsey; 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