TITLE:
Facies Analysis and Depositional Environment of the Oligocene-Miocene Asmari Formation, Bandar Abbas Hinterland, Iran
AUTHORS:
Mahdi Hoseinzadeh, Jahanbakhsh Daneshian, Seyed Ali Moallemi, Ali Solgi
KEYWORDS:
Asmari Formation, Depositional Environment, Microfacies, Ramp, Bandar Abbas Hinterland, Iran
JOURNAL NAME:
Open Journal of Geology,
Vol.5 No.4,
April
9,
2015
ABSTRACT: The Asmari Formation is a
thick carbonate sequence of the Oligocene-Miocene in the Zagros Basin,
southwest of Iran. This formation is located in Bandar Abbas and Coastal Fars
regions on the following two sections: Anguro anticline (west-northwest of
Bandar Abbas) and Gavbast anticline (southwest of Lar County). The Asmari
Formation has diameters of 68 and 26 m in the Anguro and Gavbast sections, respectively.
This formation is composed of limestone, dolomitic limestone and an altered
form of marl. Based on the results of petrographic analyses, 7 facies were
identified in the Anguro and Gavbast sections in the study region. The facies
were deposited on the following 3 belts: tidal flat (MF 1 - 3), lagoon (MF 4 -
5) and open marine (MF 6, 7). According
to evidence such as the gradual change of microfacies, the lack of main reef
barriers, and the lack of slumping and sliding features, the Asmari Formation was
formed in a marine environment of carbonate homoclinal ramp type. This
environment is composed of the following two subenvironments: the inner ramp
and the middle ramp. The comparison of the facies identified in the Anguro and
Gavbast sections indicates that Gavbast section is mainly composed of lagoon
facies. Moreover, the Anguro section demonstrates more facies diversity than
Gavbast section.