Geosynclinal Filling: Some Stratigraphic-Structural Relationships: ABSTRACT

Abstract

A geosyncline does not develop by mere crustal sag but rather by movement along faults. Contemporaneous faults are known to have been active during development of the large Ouachita and Gulf Coast geosynclines and development of the small but active Los Angeles, Hanna, and Ardmore basins, which are tectonically similar. The sedimentary fill of tectonically similar geosynclines, however, may be quite different. The Los Angeles Basin along the continental margin received thick turbidite deposits before it was filled to shelf depths. During its rapid subsidence, the Hanna Basin within the landlocked western interior filled with alluvial deposits. The Ardmore Basin during the late Paleozoic received shallow marine and coastal (paralic) sediments. Disharmonic folds involving the thick, ductile Springer-Goddard Shale indicate the influence of rock type in forming local structural features. While the Springer Shale was being deposited in the Ardmore Basin, turbidites were being deposited along the length of the Ouachita geosyncline. After water depths shoaled, shallow marine beds of the Atokan were deposited. The over-all regressive sequence of the Tertiary in the Gulf Coast geosyncline has resulted in paralic sediments overlying ductile, offshore, and deep-water shales. This relation may have been the cause of structures formed independently of salt tectonics. Such features are thought to be analogous to those failures recognized causing failures in foundation engineering and to the Recent mudlumps of the Mississippi River. End_of_Article - Last_Page 358------------