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Marion Dufresne Coring in Chesapeake Bay
From June to September, 1999, IMAGES is sponsoring a large part of an oceanographic cruise by the French coring ship the Marion Dufresne in the Caribbean, North Atlantic, Nordic, and adjacent seas. As part of this larger effort, the U.S. consortium sponsored a portion of the cruise to collect long sediment cores in Chesapeake Bay. Sediment coring in the Chesapeake took place on June 20-22, 1999. A group of 18 U.S. scientists boarded the ship from a launch out of Cape Henry, Virginia, in rough seas. This group included principal investigators Tom Cronin (USGS-Reston), Steve Colman (USGS-WHFC), Jeff Halka (MGS), and Peter Vogt (NRL). Other USGS participants included John Bratton and Pattie Baucom (WHFC), Debra Willard, Scott Ishman, Lisa Weimer, Robert Wagner, Tom Sheehan, and Andrew Fagenholtz (Reston), and Diane Minasian (Menlo Park). Other U.S. scientists came from NRL, MGS, the University of Rhode Island (URI), and the University of South Carolina. Operations Chief Yvon Balut directed the Marion Dufresne coring crew, and co-chief scientist, Elisabeth Michel, and the U.S. principal investigators supervised the U.S and international scientific staff. Seven members of the U.S. Chesapeake team remained on the ship until a port call in Quebec City, Canada, on June 29, to continue processing Chesapeake cores and assist with other Holocene coring operations off New Jersey and in the St. Lawrence River.
Previous stratigraphic investigations of Chesapeake Bay have been hampered by the limitations of piston and other coring methods. With the exception of a 7.5-m-long Mackereth core taken off the Rhode River in 1998 by Steve Colman and John King (URI), prior piston coring has only recovered the upper 450 cm of bay sediments. Depending on the sediment accumulation rate and erosional history at any particular site, this interval typically represents only the last 2000 years. Thus, coring by the Marion Dufresne (length 120 m, draft 7 m) also allowed the testing of the potential of the giant piston corer, typically used in deep and mid-depth oceanic sediments, to recover relatively long sedimentary records in extremely shallow-water environments.
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in this issue:
Chesapeake Bay
Association for Women Geoscientists
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