Testing the Sequence Stratigraphy Model: Response Of Fusulinacean Fauna to Sea-Level Fluctuations (Examples From Pennsylvanian and Cisuralian of the Pricaspian–Southern Urals Region)
Vladimir I. Davydov, Tamra A. Schiappa, Walter S. Snyder, 2003. "Testing the Sequence Stratigraphy Model: Response Of Fusulinacean Fauna to Sea-Level Fluctuations (Examples From Pennsylvanian and Cisuralian of the Pricaspian–Southern Urals Region)", Micropaleontologic Proxies for Sea-Level Change and Stratigraphic Discontinuities, Hilary Clement Olson, R. Mark Leckie
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The Pricaspian and southern Urals region is paleogeographically situated between the Boreal and Tethyan provinces and comprises taxa of both affinities. Both sedimentologic analyses and the graphic correlation (GC) technique was used to clarify the Pennsylvanian and Cisuralian sequence stratigraphic framework in the Pricaspian and southern Urals region. Fusulinacean zones utilized for the region are based on a well established evolutionary framework. The study of phylogenetic successions combined with GC were used to distinguish between locally controlled initial occurrences and speciation. In the Pricaspian and southern Urals region, sequence boundaries coincide with the bases of several fusulinacean zones. These eustatic events (i.e., sea-level lowstand) correspond with significant extinction in fusulinacean evolution. The base of the Asselian (i.e., the base of the Permian), the base of the Sakmarian, and some fusulinacean zones coincide with highstands. Therefore, fusulinacean speciation appears to be associated with both highstands and lowstands. Sea-level lowstands may have been very stressful for global fusulinacean assemblages and may have been a catalyst for both speciation and extinction. Highstands also may have created environmental opportunities and appear to be associated more closely with fusulinacean speciation than with extinction. Sequence boundaries located within fusulinacean zones perhaps reflect local tectonism or local climatic changes.