Depositional Environment and Sequence Stratigraphy of the Oligocene-Miocene Deposits North and East of Dehdasht, Izeh Zone, Zagros Basin, Iran

Document Type : Original Research Articles

Authors
Reza Moussavi-Harami 1
Farrokh Naseri-Karimvand 2
Asadollah Mahboubi 1
A. Ghabeishavi 3
Ruhollah Shabafrooz 4
1 Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Iran
2 Department of Geology, Faculty of Science, International Campus, Ferdowsi University of Mashhad, Iran
3 National Iranian South Oil Company (NISOC), Ahwaz, Islamic Republic of Iran
4 National Iranian South Oil Company (NISOC), Ahwaz 61735-1333, Iran
10.22059/jsciences.2019.71750
Abstract
In this study, four well-exposed outcrops of the Asmari Fm in the southeastern part of the Izeh Zone of the Zagros Mountains were measured and sampled. In this region, the Asmari Fm is Oligocene to Early Miocene in age as determined by large benthic foraminifera. Based on depositional geometries, biogenic contents and lateral and vertical variations of facies, three depositional models are proposed to illustrate the evolution of the Asmari carbonate platform. During the Chattian, large benthic foraminifera and coral-coralline red algae were dominant, while through the Early Miocene time interval (Aquitanian-Burdigalian), non-skeletal components along with porcelaneous foraminifera were the most conspicuous elements. These deposits formed a carbonate ramp in the Chattian and a low angle carbonate-ramp during the Early Miocene. Five major 3rd-order depositional sequences have been identified based on stratal stacking patterns and facies relationships. These depositional sequences show systematic progradations from SE to NW into and over the basinal Pabdeh Fm during Oligo-Miocene times.
Keywords
Asmari Fm
Zagros Mountains
Oligocene-Miocene
sequence stratigraphy
Subjects
Journal of Sciences, Islamic Republic of Iran
Volume 30, Issue 2 - Serial Number 2
Spring 2019
Pages 143-166