Structure and evolution of Baltimore Canyon Trough
Baltimore Canyon Trough is the deepest depocenter for Mesozoic and Cenozoic sedimentary rocks along the U.S. Atlantic continental margin, with up to 18 km deposited beneath the continental shelf off New Jersey (Figs. 1,2, and 3). The landward edge of the trough is marked by a hinge zone where an abrupt increase in depth to basement is observed on seismic reflection profiles. The depth to the top of basement at the hinge zone usually occurs between 4 and 6 km, but secondary hinge zones in places are observed where basement is as shallow as 1 km or as deep as 8 km. The depth to basement increases toward the East Coast Magnetic Anomaly (ECMA), which marks the landward edge of oceanic crust. The width of the trough, as measured by the distance between the hinge zone and the main axis of the ECMA, varies from 60 km off Virginia to 100 km off New Jersey. In the northern half of the trough, the Jurassic paleoshelf edge complex has prograded seaward of the ECMA onto the oceanic crust by as much as 40 km (Figs. 2 and 4). During the late Cenozoic, the shelf edge, as defined by the present 200-m isobath, has retreated by 10 to 20 km from its prior position during Late Jurassic through early Cenozoic. The distance from the hinge zone to the Jurassic shelf edge varies from 50 km off Virginia to 140 km off New Jersey (Fig. 2).
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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.