Tarbur Maastrichtian to Taleh Zang Paleocene carbonate platforms: age-determination, facies analysis and depositional architecture

Maastrichtian to Thanetian carbonate platforms comprise the outcrops of scarcity, especially in Tethys, Zagros Foreland Basin of which is hardly documented. A carbonate platform-to-basin transect in Zagros Basin was done, consisting of two important outcrops, and large cliffs with a vast landscape and good photographic capacity. Based on large benthic foraminifera (LBF) and planktonic foraminifera, these carbonate platforms are referred to as Tarbur and Taleh Zang formations, which are dated to the Maastrichtian and Paleocene (Thanetian-Selandian). Multiple stratigraphic approaches, along with the facies analysis, were used to build the carbonate platform architecture and figure out the most conspicuous factors controlling the evolution of these platforms through time. Ten sedimentary facies belts were identified, ranging from the basin to the proximal and distal shallow-water contexts with carbonate ramps. The distribution of grain-associations in the spatial and temporal scale, facies belts, apparent stratal geometry, and biological evolution accompanied by age dating led to identifying two distinct carbonate models: Maastrichtian distally steepened ramp and Paleocene carbonate ramp, belonging to Tarbur and Taleh Zang carbonate formations, respectively. Due to the first dominating community of Cenozoic Zooxanthellate corals associated with red coralline algae as separate patches, the Paleocene Taleh Zang carbonate ramp was divided into two carbonate modes: Danian-lower Selandian and upper Selandian.