Florence Bascom Geoscience Center

Publications

Filter Total Items: 349
Publication Thumbnail
Year Published: 2019

Paleocene–Eocene Thermal Maximum prolonged by fossil carbon oxidation

A hallmark of the rapid and massive release of carbon during the Palaeocene–Eocene Thermal Maximum is the global negative carbon isotope excursion. The delayed recovery of the carbon isotope excursion, however, indicates that CO2 inputs continued well after the initial rapid onset, although there is no consensus about the source of this...

Lyons, Shelby L.; Baczynski, Allison A.; Babila, Tali L.; Bralower, Timothy J.; Hajek, Elizabeth A.; Kump, Lee R.; Polites, Ellen G.; Self-Trail, Jean M.; Trampush, Sheila M.; Vornlocher, Jamie R.; Zachos, James C.; Freeman, Katherine H.

Publication Thumbnail
Year Published: 2019

The planktonic foraminiferal response to the Paleocene-Eocene thermal maximum on the Atlantic coastal plain

Planktonic foraminiferal assemblages in two cores from Maryland and New Jersey show evidence for significant changes in surface ocean habitats on the continental shelf during the Paleocene-Eocene Thermal Maximum (PETM). At both sites, significant assemblage shifts occur immediately before the onset of the event. These changes...

Livsey, Caitlin M.; Babila, Tali; Robinson, Marci M.; Bralower, Timothy J.

Publication Thumbnail
Year Published: 2019

Chesapeake Bay impact structure—Development of "brim" sedimentation in a multilayered marine target

The late Eocene Chesapeake Bay impact structure was formed in a multilayered target of seawater underlain sequentially by a sediment layer and a rock layer in a continental-shelf environment. Impact effects in the “brim” (annular trough) surrounding and adjacent to the transient crater, between the transient crater rim and the outer margin,...

Dypvik, Henning; Gohn, Greg; Edwards, Lucy; Horton, J. Wright; Powars, David; Litwin, Ronald

Publication Thumbnail
Year Published: 2019

Evidence for shelf acidification during the onset of the Paleocene-Eocene Thermal Maximum

A transect of paleoshelf cores from Maryland and New Jersey contains a ~0.19 m to 1.61 m thick interval with reduced percentages of carbonate during the onset of the Paleocene-Eocene Thermal Maximum (PETM). Outer paleoshelf cores are barren of nannofossils and correspond to two minor disconformities. Middle paleoshelf cores contain a mixture of...

Bralower, Timothy J.; Kump, Lee R.; Robinson, Marci M.; Self-Trail, Jean M.; Lyons, Shelby L.; Babila, Tali; Ballaron, Edward; Freeman, Katherine H.; Hajek, Elizabeth A.; Rush, William; Zachos, James C.

Publication Thumbnail
Year Published: 2019

Appalachian Basin stratigraphy, tectonics, and eustasy from the Blue Ridge to the Allegheny Front, Virginia and West Virginia

This guide is from a two-day field trip in western Virginia and eastern West Virginia held before the 2015 Geological Society of America annual meeting in Baltimore, Maryland. The field trip examines exposures of Paleozoic sedimentary strata in the Appalachian Basin starting in the Blue Ridge physiographic province, going through the Valley and...

Haynes, John T.; Pitts, Alan D.; Doctor, Daniel H.; Diecchio, Richard J.; Blake, Mitchell B.

Publication Thumbnail
Year Published: 2019

The impact of late Holocene land-use change, climate variability, and sea-level rise on carbon storage in tidal freshwater wetlands on the southeastern United States Coastal Plain

This study examines Holocene impacts of changes in climate, land use, and sea-level rise (SLR) on sediment accretion, carbon accumulation rates (CAR), and vegetation along a transect of tidal freshwater forested wetlands (TFFW) to oligohaline marsh along the Waccamaw River, South Carolina (4 sites) and along the Savannah River, Georgia (4 sites)....

Jones, Miriam; Bernhardt, Christopher E.; Krauss, K.W.; Noe, Gregory B.

Publication Thumbnail
Year Published: 2018

Surficial materials of Massachusetts—A 1:24,000-scale geologic map database

The surficial materials geologic map database defines the distribution of nonlithified earth materials at the land surface in the 189 7.5-minute, 1:24,000-scale quadrangles that cover the Commonwealth of Massachusetts (index map). Across the State, these materials range in thickness from a few feet to more than 500 feet (ft). In some places,...

Stone, Janet Radway; Stone, Byron D.; DiGiacomo-Cohen, Mary L.; Mabee, Stephen B.
Stone, J.R., Stone, B.D., DiGiacomo-Cohen, M.L., and Mabee, S.B., comps., 2018, Surficial materials of Massachusetts—A 1:24,000-scale geologic map database: U.S. Geological Survey Scientific Investigations Map 3402, 189 sheets, scale 1:24,000; index map, scale 1:250,000; 58-p. pamphlet; and geodatabase files, https://doi.org/10.3133/sim3402.

Publication Thumbnail
Year Published: 2018

Ecological changes in the nannoplankton community across a shelf transect during the onset of the Paleocene-Eocene Thermal Maximum

Warming and other environmental changes during the Paleocene‐Eocene thermal maximum (PETM) led to profound shifts in the composition and structure of nannoplankton assemblages. Here we analyze the nature of these changes in expanded records from the Cambridge‐Dorchester and Mattawoman Creek‐Billingsley Road cores in Maryland. These cores comprise...

León y León, Isabel A.; Bralower, Timothy J.; Self-Trail, Jean M.

Publication Thumbnail
Year Published: 2018

North Atlantic midlatitude surface-circulation changes through the Plio-Pleistocene intensification of northern hemisphere glaciation

The North Atlantic Current (NAC) transports warm salty water to high northern latitudes, with important repercussions for ocean circulation and global climate. A southward displacement of the NAC and Subarctic Front, which separate subpolar and subtropical water masses, is widely suggested for the Last Glacial Maximum (LGM) and may have acted as a...

Bolton, Clara T.; Bailey, Ian; Friedrich, Oliver; Tachikawa, Kazuyo; de Garidel‐Thoron, Thibault; Vidal, Laurence; Sonzogni, Corinne; Marino, Gianluca; Rohling, Eelco J.; Robinson, Marci M.; Ermini, Magali; Koch, Mirjam; Cooper, Matthew J.; Wilson, Paul A.

Publication Thumbnail
Year Published: 2018

Quaternary eolian dunes of the Atlantic Coastal Plain Province, USA

Eolian sand dunes and sand sheets of Quaternary age are present at many inland locations throughout the Atlantic Coastal Plain province of the eastern United States. Under modern conditions, this region is not very conducive to widespread eolian sediment mobilization because of a humid and mesothermal climate, relatively low mean surface wind...

Swezey, Christopher S.

Publication Thumbnail
Year Published: 2018

The Central African Republic Diamond Database—A geodatabase of archival diamond occurrences and areas of recent artisanal and small-scale diamond mining

The alluvial diamond deposits of the Central African Republic (CAR) are mined almost exclusively by way of informal artisanal and small-scale mining (ASM) methods. ASM sites range in diameter from a few meters to 30 meters or more, and are typically excavated by crews of diggers using hand tools, sieves, and jigs. CAR’s reported annual production...

DeWitt, Jessica D.; Chirico, Peter G.; Bergstresser, Sarah E.; Clark, Inga E.
DeWitt, J.D., Chirico, P.G., Bergstresser, S.E., and Clark, I.E., 2018, The Central African Republic Diamond Database—A geodatabase of archival diamond occurrences and areas of recent artisanal and small-scale diamond mining: U.S. Geological Survey Open-File Report 2018–1088, 28 p., 1 pl., https://doi.org/10.3133/ofr20181088.

Publication Thumbnail
Year Published: 2018

The significance of dinoflagellates in the Miocene Choptank Formation beneath the Midlothian gravels in the southeastern Virginia Piedmont

The Fall Line (formally “Tidewater Fall Line”) separates the more resistant igneous, metamorphic, and consolidated sedimentary rocks of the Piedmont from the typically unconsolidated deposits of the Coastal Plain of Virginia. Widespread but now discontinuous patches of a deeply weathered sand and gravel are found west of the Fall Line, capping...

Edwards, Lucy E.; Weems, Robert E.; Carter, Mark W.; Spears, David B.; Powars, David S.