Abstract: Preliminary Biostratigraphy of U.S. Atlantic Continental Margin

C. Wylie Poag, Page C. Valentine, Charles C. Smith

The U.S. Geological Survey Atlantic Coring Project (AMCOR) has obtained cores from 20 continuously cored boreholes (1,000 ft or 305 m maximum penetration) drilled on the Atlantic continental slope between Georgia and Massachusetts. Preliminary analyses of planktonic and benthic foraminifers, calcareous nannoplankton, and diatoms provide means for determining the biostratigraphic zonation; for correlation with onshore wells, the COST B-2 stratigraphic test well, and core holes at the base of the continental slope; and for paleoenvironmental interpretations.

The southernmost AMCOR core holes, off Georgia and South Carolina, penetrated a nearly complete Tertiary sequence. One core hole terminated in beds of Maestrichtian age; pelagic fossil assemblages are common here. Northward, off Maryland, Delaware, and Massachusetts, the strata cored are mainly of Pleistocene and Miocene age. In these areas, the sediments originated in shallower water. Lagoonal, inner-shelf, and middle-shelf paleoenvironments predominate. Consequently, most microfossils are of benthic species, except for rich diatom floras in the Miocene strata.

The presence of diverse fossil groups in the samples allows an integrated approach that is vital for this initial biostratigraphic and paleoenvironmental interpretation of the Atlantic continental margin.

AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC