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Full Length Research Paper
Microfacies and
sedimentary environment of the Oligo- Miocene sequence (Asmari
Formation) in Khuzestan sub- basin, Zagros Basin, southwest
Iran
Mahnaz Parvaneh Nejad Shirazi¹*, Mohsen Davoudi Nezhad²
and Hormuz Ghalavand³
¹’²Department of Geology, Payame Noor University, PO BOX
19395-3697 Tehran, IRAN.
³ National Iranian South Oil Company (NISOC)
*Corresponding author E-mail:
Mahnaz402002@yahoo.com , Tel.: +98 711 622255, Fax: +98
711 6222244
Received 20 December , 2011; Accepted 09 January, 2012
The Asmari Formation is a thick carbonate succession of the
Oligo-Miocene in Zagros Basin. The Oligocene-Miocene Asmari
Formation, Chidan area, is composed of limestone and
calcareous marl. The Asmari Formation has a conformable
contact with the overlying (Gachsaran Formation) and the
underlying (Pabdeh Formation) units and is subdivided into
three members. In order to interpret the facies and
depositional environment of the Asmari Formation, two
measured sections were studied in Chidan area for
microfacies analyses. In this study, eight different
microfacies types have been recognized on the petrographic
studies, field observations, identification of larger
foraminifera and facies studies of the Asmari Formation (Chidan
section). These carbonate microfacies belonging to four
major subenvironments: open marine (A), bar/shoal (B),
lagoon (C) and tidal flat (D). The depositional environment
of the Asmari Formation is interpreted as a shallow
carbonate ramp. The most of the Asmari Formation in the
study area was deposited in an inner ramp environment.
Keywords:
Asmari Formation, Chidan, Gachsaran, Pabdeh, Iran.
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