Subsidence and Thermal History of Small Pull-Apart Basins1
Published:January 01, 1985
W. C. Pitman, III, J. A. Andrews, 1985. "Subsidence and Thermal History of Small Pull-Apart Basins", Strike-Slip Deformation, Basin Formation, and Sedimentation, Kevin T. Biddle, Nicholas Christie-Blick
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The very rapid subsidence, sediment accumulation, and hydrocarbon maturation observed in many small extensional or “pull-apart” basins can be explained using a McKenzie-type model. It has been shown that in basins of 100 km width or less, lateral heat loss is quite important and accelerates lithospheric cooling and subsidence. We show here that cooling that is simultaneous with stretching is very important for basins formed by stretching of lithospheric blocks that are 10 km to several tens of kilometers wide. In fact, for most of these very narrow basins, most of the anomalous heat introduced by stretching is also dissipated during the stretching event. We have calculated the effect of alternate short periods of stretching and cooling to approximate simultaneous stretching and cooling. The results show, for example, that for a block, initially 10 km wide and stretched uniformly at 3 cm/yr, sufficient subsidence will take place in 200,000 years to accumulate 4—5 km of sediment. A consequence of this rapid subsidence is initial sediment starvation. These results may be applicable to many of the small extensional basins associated with the San Andreas transform system.
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Strike-Slip Deformation, Basin Formation, and Sedimentation
This Special Publication is an outgrowth of a Research Symposium held at the 1984 joint meeting of SEPM and AAPG in San Antonio, Texas. In recent years a significant body of new geological and geophysical data on strike-slip basins had been acquired, and there had been significant progress in understanding the mechanisms by which basins form and deform in strike-slip settings. This volume emphasizes the relations between deformation patterns along strike-slip faults, the mechanisms by which basins form and the configuration of sedimentary facies within such basins.