Paleoecology and Sedimentary Environments of the Oligo-Miocene Deposits of the Asmari Formation (Qeshm Island, SE Persian Gulf)

Abstract

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.

Sedimentological Studies of Marine Oil Fields in Order to Reduce Drilling Risk and Environmental Pollution: A Case Study of South of Iran

“…Sarvak Formation is known as a reservoir rock and Kazhdomi Formation is known as a very important source rock in most of Iran's oil fields [12,44]. Knowing the facies and sequences of these two formations along with their lateral changes in understanding them better is necessary to calculate the production and accumulation of hydrocarbons [15,36].…”

Sedimentological studies of marine oil fields in order to reduce drilling risk and environmental pollution: a case study of South of Iran

“…Sarvak Formation is known as a reservoir rock and Kazhdomi Formation is known as a very important source rock in most of Iran's oil fields (4,5). Knowing the facies and sequences of these two formations along with their lateral changes in understanding them better is necessary to calculate the production and accumulation of hydrocarbons (6,7).…”

Facies analysis and depositional environment of the Oligocene–Miocene Asmari Formation, in Interior Fars (Zagros Basin, Iran)

“…Afterwards this Formation were studied by Richardson (1924), De Böckh et al (1929), Lees (1933), Zabihi Zoeram et al (2013), Aiello (2019), Monjezi et al (2019), that revised the age of Asmari Formation to the Oligocene-Miocene. This formation was defined regionally based on lithological and paleontological analysis (James and Wynd 1965;Adams and Bourgeois 1967;Motiei 1993;Aiello 2019;Hosseini Asgarabadi et al 2019;Sajadi and Rashidi 2019) and was deposited on a tropical platform, which covered southwestern Iran and parts of Iraq (James and Wynd 1965). More recent studies of the Asmari Formation were reported by (Ehrenberg et al 2007;Van Buchem et al 2010;Rahmani et al 2012;Ehrenberg and Baek 2019;Farshi et al 2019;Gharechelou et al 2020).…”