Biostratigraphy and carbon-isotope stratigraphy of the uppermost Aptian to Upper Cenomanian strata of the South Palmyrides, Syria

Abstract

ABSTRACT Biostratigraphic and carbon-isotope data were used to introduce a high-resolution stratigraphic reference section of the Upper Aptian to Upper Cenomanian platform carbonates of the South Palmyrides in Syria. We studied the biostratigraphic evolution of the Zbeideh to Abou-Zounnar formations in two sections, based on 42 species of benthonic foraminifera and 38 species of planktonic foraminifera. Comparisons with other Tethyan assemblages allowed determining 11 biozones; six are based on planktonic foraminifera, and five on benthonic foraminifera. Four hiatuses (earliest Albian, Middle–Late Albian, Late Albian–Early Cenomanian, and Mid Cenomanian) are marked by hardgrounds or dolomitic intervals. The planktonic biozones Ticinella bejaouaensis, T. primula, T. praeticinensis, Rotalipora subticinensis, R. globotruncanoides and R. cushmani co-occur with the following benthonic biozones: Mesorbitolina texana partial range zone, M. subconcava range zone, Neoiraqia convexa taxon-range zone, Praealveolina iberica interval zone and Pseudedomia drorimensis range zone. Within this biostratigraphic framework, a new carbon-isotope curve from the South Palmyrides was compared with δ13C records of the Tethyan Realm and England that allows identifying several biotic events and Oceanic Anoxic Events (OAE), recorded in the Upper Albian to Upper Cenomanian succession. The combination of sequence-stratigraphic interpretations and comparisons, with our results have led to an improved understanding of the Cretaceous platform architecture of the South Palmyrides that links the Arabian Platform to the east with the Levant Platform to the southwest.