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The AAPG/Datapages Combined Publications Database

GCAGS Transactions


Gulf Coast Association of Geological Societies Transactions
Vol. 46 (1996), Pages 481-481

Abstract: Models for the Development of Listric Normal Faults and Previous HitFaultNext Hit Seals

John B. Spang


Previous models for constructing, restoring and forward modeling of listric normal faults have used either vertical or inclined, antithetic simple shear. Although these models have been successfully applied in some cases, they fail to account for important attributes of major Gulf Coast listric normal faults, such as synthetic faults, Previous HitfaultNext Hit smear, "normal" drag folding and displacement gradients from as little as zero at the top layer to a maximum at depth. The new model contains two active deformation zones or zones of shearing in the hanging wall. One active deformation zone is antithetic to the main Previous HitfaultNext Hit and is fixed in space at bends in the Previous HitfaultNext Hit plane. As the rocks move through the Previous HitfaultNext Hit bend, they are sheared according to the existing model of inclined shear. The other active deformation zone is also fixed in space at Previous HitfaultNext Hit bends, but it is synthetic to the main Previous HitfaultNext Hit. As the rocks pass through this zone, they are sheared both synthetically and antithetically. When the dip on the synthetic zone of shearing approaches the dip on a segment of the main Previous HitfaultNext Hit, the method simulates the development of synthetic faults and/or Previous HitfaultNext Hit smear. Application of this method may lead to a better prediction of Previous HitfaultNext Hit seals, zones of porosity and Previous HitfaultTop closure.

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Department of Geology and Geophysics, Texas A&M University, College Station, TX, 77843-3115

Copyright © 1999 by The Gulf Coast Association of Geological Societies