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The Asmari Formation is composed of limestones, marly limestones, and marls, whose subsurface thickness in this region is about 148 m. Two assemblage zones have been recognized through the distribution of large foraminifera in the study area, indicating a Late Oligocene (Chattian)-Early Miocene (Aquitanian) age. The gradual facies changes and the lacking of turbiditic deposits show that the Asmari Formation was deposited in a carbonate ramp environment. Based on the depositional textures and petrographical studies, characterizing gradual shallowing upward trends of an open marine carbonate ramp, three distinct depositional settings have been recognized: lagoon, barrier, and open marine. MF1 was characterized by the occurrence of hyaline benthic and planktonic foraminifera representing distal middle ramp and below the storm wave base of other ramp. Paleolatitudinal reconstructions based on skeletal grains suggest that carbonate sedimentation of the Asmari Formation took place in tropical waters within the photic zone.

The purpose of this study is lithostratigraphic investigation of Oligocene-Miocene salt deposits in the SE Persian Gulf. This study is based on lithostratigraphy and biostratigraphy data, gamma ray and sonic logs of nine drilled wells along southeast Persian Gulf to Strait of Hormuz. As a result, the Oligocene-Miocene deposits of this region were subdivided into four formations (Fms) which include Pabdeh Fm (Rupelian-Chattian), Asmari Fm (Rupelian-Aquitanian), Gachsaran Fm (Aquitanian) and Mishan Fm (Burdigalian). The salt and evaporated deposits situated between the Pabdeh and Gachsaran Fms which are assigned to the Aquitanian age. Finally the stratigraphical setting and distribution of the salt deposits are cleared.