Pliocene Stratigraphy of the South Caspian Basin – Microfauna, and Palaeoenvironment of the Productive Red Series

Ebook

Azerbaijan Society of Petroleum Geologists

This book details the biostratigraphy of the Productive and Red series in the South Caspian Basin by analysis of the ostracod fauna and reconstructing the Lower Pliocene palaeogeography and palaeoenvironments of the South Caspian Basin. Author examined 151 core samples collected from 41 deep wells drilled over 29 structures. Ostracods rapid-evolutionary trend and changing assemblages in Lower Pliocene biostratigraphy, supported by recorded wells log data. Using seismic, log and biostratigraphy data it is possible to reconstruct palaeoenvironments of the Productive and Red series of the South Caspian Basin. Ostracods in the Pliocene time were originally inhabitants of the Pontian brackish basin. In the Early Pliocene, the basin gradually freshened with continuous regression. The increasing sedimentation rate in the basin during the deposition of these time caused the shallowing of the basin and considerable turbidity of the water, which created unfavourable conditions for the life and fossilisation process of the benthic organisms. Microfaunal diversity and population density in the offshore Pliocene Productive and Red series are considerably lesser than that of the onshore series. Three ostracod assemblages were used in the stratigraphic subdivisions of the Pliocene in the South Caspian. Ostracod taxa are typical representative of saline, euryhaline, and brackish environment.