TITLE:
Facies, Depositional Environment and Diagenesis of the Qom Formation in Rameh Section (Northeastern Garmsar)
AUTHORS:
Soraya Sardarabadi, Davood Jahani, Nader Kohansal Ghadimvand
KEYWORDS:
Rimmed Shelf, Porosity, Qom Formation
JOURNAL NAME:
Open Journal of Geology,
Vol.6 No.10,
September
30,
2016
ABSTRACT: Deposits
of the Qom Formation (Oligocene-Miocene) in Rameh section are located in northeastern
Garmsar and contain dominantly 420 m Limestone, pebble-rich to sandy Limestone
and marl Limestone. This formation is unconformably overlaid and underlaid with
siliciclastic deposits of Upper Red Formation and Lower Red Formation. Field
observations, along with laboratory investigations, have resulted in
identifying tidal flat, lagoon, shoal and open marine environments in the
studied formation. Open marine facies association consists of bioclast
mudstone, bioclast wackestone, bioclast packstone and bioclast roadstone; shoal facies
association consists of ooid grainstone, bioclast grainstone and coral
boundstone; lagoon facies association is
composed of dolomitic mudstone, intraclast bioclast wackestone and bioclast packstone; and tidal flat facies association is sandy
dolomudstone and stromatolite boundstone. The qom formation rocks in Rameh
section are deposited in a rimmed shelf carbonate ramp. This formation
undergoes various diagenetic processes including dissolution, porosity,
cementation, micritization, compaction and dolomitization.