Biostratigraphy and paleoecology of Razak Formation in southeast of Jahrum (Type section)

In order to study biostratigraphy and paleoecology of the Razak Formation, the type locality about 37 km southwest of Jahrum, was selected. Thickness of the Razak Formation at type section is 500 meters that conformably overlies the limestone of the Asmari Formation and is overlain by the Mishan Formation. 20 genera and 27 species of foraminifera and 2 faunal assemblages were recognized. As a result, the Razak Formation is Chattian Aquitanian (Late Oligocene–Early Miocene) in age. Association of carbonate grains of the Razak Formation at type section, considering presence of large benthic foraminifera accompanied with other accessory skeletal grains such as bryozoan, corallinacean algae, echinoid and gastropod and lack of colonial corals and green algae can be classified in foramol and heterozoanassemblages.