چينه نگاري سكانسي نهشته هاي سازند قم در ناحيه الگو (برش كوه بيچاره) در جنوب شرق قم، شمال ايران مركزي

Sequence stratigraphy of the Qom Formation at Type Area(Kuh-e-Bichareh section),in Southeast Qom, North of Central Iran

In order to study of sequence stratigraphy of the Qom Formation in southwest of Qom and northwest of Aran,a stratigraphy section in Shourab area was selected. The sediments(Kuh-e-Bichareh) of this section with 631 m thickness overlies the Lower Red Formation and underlies the Upper Red Formation. The studied section is situated at the type area of the Qom Formation, and mainly consists of limestone, sandy limestone, argillaceous limestone, sandstone, shale, marl and gypsum. All members of the Qom Formation, except the unnamed member exist in the examined section. A total 185 samples including 70 soft and 115 hard was collected. Based on the index foraminifera the suggested age of the Qom Formation in Kuh-e- Bichareh section is Aquitanian to Burdigalian. The microfacies studies were led to recognition four facies belts including tidal flat, lagoon, barrier and open marine. According to field & laboratory studies 6 sequences and 7 sequence boundries introduced which 2 sequence boundries are comparable with world sea level changes and other probably are related to tectonic in the studied area.