Biostratigraphy, palaeoenvironments and sequence stratigraphy of the Aptian sedimentary succession at Jebel Bir Oum Ali (Northern Chain of Chotts, South Tunisia): Comparison with contemporaneous Tethyan series

摘要: Abstract The Aptian sedimentary succession of the Chott region in southern Tunisia was deposited on margin Saharan shield, and is punctuated by numerous hiatuses that separate seven 3rd-order depositional sequences. Early deposits correspond to Berrani Member (early Bedoulian), which contemporaneously with large carbonate platforms rudists developed under oligo-mesotrophic, tropical environmental conditions both margins Tethys. Late Bedoulian sediments were mesotrophic characterized seagrass, algae, abundant orbitolinids aragonite-producing organisms. early late transition marked temporary disappearance an important renewal microfauna, whose tests skeletons became less aragonite-rich more calcite-rich arenaceous. This episode reported from Tethyan margins. platform subsequently flooded, dysoxic environments annelids end development. An arid probably colder (earliest Aptian) induced deposition gypsum intrashelf basin. Following top, return humid triggered enhanced input detrital material fluvio-deltaic (late Aptian). Finally, marine allowed installation wide lagoons latest earliest Albian. Long-distance correlations have been established means benthic foraminiferal occurrences. They highlight importance stratigraphic gaps linked low sea levels, tentatively estimated.