Paleoenvironments: Offshore Atlantic U.S. margin
Published:January 01, 1988
The U.S. Atlantic continental margin, which stretches 1,850 km from Georges Bank in the north to the Blake Plateau in the south, encompasses an area of 655,000 km2. The margin comprises several sedimentary basins of different shapes with platforms in between (see Schlee and Klitgord, this volume). The basins appear to have begun their subsidence at about the same time and to have undergone similar rift and postrift phases of development that resulted in a similar sedimentary section (Schlee and Jansa, 1981). Our objectives in this paper are (1) to portray, at selected intervals, the paleogeography of the margin during the Mesozoic and Cenozoic, (2) to discuss the temporal development of the paleoshelf edge, and (3) to outline the major elements of the several different sedimentary regimes that have prevailed (rift, postrift, carbonate-clastic, and authigenic sediment accumulations).
The main sources of data are interpretations of multichannel seismic-reflection profiles (Dillon 1982; Dillon and others, 1983a; Grow and others, 1979; Schlee, 1981; Schlee and Fritsch, 1982; Schlee and others, 1985), released drill hole data (Scholle, 1977,1979, 1980; Scholle and Wenkam, 1982; Poag, 1982a, b; Libby-French, 1981, 1984), and Deep Sea Drilling Project (DSDP) data (Hollister and Ewing, 1972; Tucholke and Vogt, 1979; Benson and Sheridan, 1978; Sheridan, and Gradstein, 1983; Van Hinte and Wise, 1987; Poag and Watts, 1987). With few exceptions (Schlee, 1981; Schlee and Fritsch, 1982), published interpretations of offshore basins have been based on a detailed analysis of one or at best a few key profiles (Grow and others, 1979, 1983; Poag, 1982a, b, 1985). Our approach in this chapter is to present interpretations in the form of eight time-slice maps with a brief discussion about data sources, paleogeography, and ties to adjacent areas.
Figures & Tables
The Atlantic Continental Margin
This synthesis covers stratigraphy, depositional processes, and geophysical interpretation of the major onshore and offshore marginal basins from Maine to the Bahamas, and includes an up-to-date review of thinking on regional tectonic history. Additional chapters discuss the theoretical aspects of thermal evolution, subsidence, and seismic stratigraphy as applied to this region. Geological resources including petroleum, water, sand and gravel, hard minerals, and heat flow are reviewed, and environmental hazards such as seismicity, coastal erosion, waste disposal and submarine instability as it relates to site of drilling platforms and mining are evaluated. A summary chapter reviews areas of controversy and suggests key topics for research.