We can use information about present and past subsurface temperatures in basins of the U.S. Atlantic Continental Margin in several ways. The event that formed the margin—rifting—had a large thermal signature. The decay of that signature led to subsidence and the accumulation of thick sediments. The temperature history of those sediments in part controlled their diagenesis. Therefore, temperature data can help understand the rifting mechanism, the rate and distribution of subsidence, and the modification of sediment after its deposition.
The present tempratures and heat flow on the U.S. Atlantic Margin are of almost no use in constraining the rifting mechanism or the subsidence. The thermal anomaly from the rift that formed the margin is nearly gone. The temperature differences that might be used to distinguish rift mechanisms decay quickly and fall below what is measurable in less than 50 m.y. This margin is at least 150 m.y. old.
The present temperature distribution is more directly useful in predicting parameters like oil and natural gas maturation in sediments. These reactions are sensitive to temperature and may be considered to be most affected by the highest sustained temperature the sediment has reached. Since sediment temperature typically increases monotonically with burial on this margin, the highest temperature reached by sediment is its present temperature.
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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.