Poag, C. Wylie (2012): Foraminiferal repopulation of the late Eocene Chesapeake Bay impact crater

Leg/Site/Hole:
DSDP 95
DSDP 95 612
Identifier:
2012-078720
georefid

0026-2803
issn

MCPLAI
coden

Creator:
Poag, C. Wylie
U. S. Geological Survey, Woods Hole, MA, United States
author

Identification:
Foraminiferal repopulation of the late Eocene Chesapeake Bay impact crater
2012
Micropaleontology
American Museum of Natural History, New York, NY, United States
58
1-2
206 pp.
The Chickahominy Formation is the initial postimpact deposit in the 85km-diameter Chesapeake Bay impact crater, which is centered under the town of Cape Charles, Virginia, USA. The formation comprises dominantly microfossil-rich, silty, marine clay, which accumulated during the final approximately 1.6myr of late Eocene time. At cored sites, the Chickahominy Formation is 16.8-93.7m thick, and fills a series of small troughs and subbasins, which subdivide the larger Chickahominy basin. Nine coreholes drilled through the Chickahominy Formation (five inside the crater, two near the crater margin, and two approximately 3km outside the crater) record the stratigraphic and paleoecologic succession of 301 indigenous species of benthic foraminifera, as well as associated planktonic foraminifera and bolboformids. Two hundred twenty of these benthic species are described herein, and illustrated with scanning electron photomicrographs. Absence of key planktonic foraminiferal and Bolboforma species in early Chickahominy sediments indicates that detrimental effects of the impact also disturbed the upper oceanic water column for at least 80-100kyr postimpact. After an average of approximately 73kyr of stressed, rapidly fluctuating paleoenvironments, which were destabilized by after-effects of the impact, most of the cored Chickahominy subbasins maintained stable, nutrient-rich, low-oxygen bottom waters and interstitial microhabitats for the remaining approximately 1.3myr of late Eocene time.
English
Serial
Coverage:Geographic coordinates:
North:38.4913
West:-76.3000East: -72.4625
South:37.0000

Stratigraphy; Applied geophysics; assemblages; Atlantic Ocean; benthic taxa; biostratigraphy; biozones; Cenozoic; Chesapeake Bay; Chesapeake Bay impact structure; Deep Sea Drilling Project; DSDP Site 612; Eocene; faunal list; Foraminifera; geophysical methods; geophysical profiles; geophysical surveys; impacts; Invertebrata; IPOD; Leg 95; lithostratigraphy; marine environment; microfossils; morphology; North Atlantic; paleoecology; paleoenvironment; Paleogene; Protista; seismic methods; seismic profiles; SEM data; surveys; taxonomy; Tertiary; United States; upper Eocene; Virginia;

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