Small Pelecypoda of Qom Formation (Early Miocene) in west of Ashtian, Central Iran

The Qom Formation is well exposed in Ashtian area (Central Iran). Pelecypoda of the formation in a stratigraphic section of west of Ashtian were examined in terms of paleontological and paleoecological criteria. In this section, the Qom Formation overlies the Lower Red Formation with a gradual contact and is disconformably overlain by Upper Red Formation. For the first time, the systematic studies of the fauna yielded four genera and two species of small pelecypoda. Common stratigraphic ranges of determinatedpelecypoda with the presence of coexistence foraminifera, give the age of Early Miocene (Aqitanian) for these layers.The distribution of the foraminifera in the studied area indicates that carbonate containing small pelecypoda of the Qom Formation were deposited in an aphotic zone of tropical to subtropical region.