Georges Bank Basin: A regional synthesis
Georges Bank is a shallow part of the Atlantic Continental Shelf southeast of New England (Emery and Uchupi, 1972, 1984). This bank, however, is merely the upper surface of several sedimentary basins overlying a block-faulted basement of igneous and metamorphic crystalline rock (Figs. 1 and 2). Sedimentary rock forms a seaward-thickening cover that has accumulated in one main depocenter and several ancillary depressions, adjacent to shallow basement platforms of Paleozoic and older crystalline rock. Georges Bank basin contains a thickness of sedimentary rock greater than 10 km, whereas the basement platforms that flank the basin are areas of thin sediment accumulation (less than 5 km). We will discuss the structural, stratigraphic, and tectonic framework of the Georges Bank area, presenting a synthesis of geophysical and geologic data, much of which has been collected over the past decade (Austin and others, 1980; Klitgord and others, 1982; Schlee and Fritsch, 1982; Klitgord and Schlee, 1986). In particular, we shall be concerned with the crustal foundations of Georges Bank, the main stages of sedimentary buildup, and the forces that we think have influenced the evolution of the basin.
A general outline of the geology of Georges Bank basin has been given by Drake and others (1959), Maher (1971), Emery and Uchupi (1972), Schultz and Grover (1974), Mattick and others (1974), Ballard and Uchupi (1975), and Schlee and Klitgord (1982). More detailed studies of the character and distribution of basement structures have been given by Klitgord and Behrendt (1979), Austin and others (1980), Klitgord and others (1982), and Klitgord and Schlee (1986). The character and deposition patterns of the overlying Mesozoic and Cenozoic sedimentary wedge have been studied in detail by Schlee (1978), Valentine (1981), Poag (1982a, 1982b), Klitgord and others (1982), and Schlee and Fritsch (1982). Quaternary evolution of the bank has been described by Emery and Uchupi (1972), Oldale and others (1974), Lewis and Sylwester (1976), and Schlee and Fritsch (1982).
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.