Biostratigraphy of the Asmari Formation at Khaviz and Bangestan Anticlines, Zagros Basin, SW Iran

Abstract

Paleontological and biostratigraphical studies on a carbonate platform succession from southwestern Iran documented a high diversity of shallow-water benthic foraminifera during the Oligocene-Miocene. Larger foraminifera are the main means for stratigraphie zonation of the As-mari Formation. The distributions of larger benthic foraminifera in two outcrop sections (Khaviz and Bangestan Anticlines) in the central part of the Zagros Fold-and-Thrust Belt (Iran) are used to determine the age of the Asmari Formation in this area. Four assemblage zones are recognized by distribution of larger benthic foraminifera in the study areas. Assemblage zone 1 is Rupelian-Chat-tian in age and occurs in the lower part of the Asmari Formation. Assemblage zone 2 suggests a Chattian age. Assemblage zone 3 indicates an Aquitanian age and Assemblages zone 4 is restricted to the Burdigalian. Assemblage zones 1 (Rupelian-Chattian) and 2 (Chattian age) were not recognized in the Asmari Formation of the Bangestan Anticline section. The Oligocène shallow carbonate part of the Asmari Formation has been replaced by the basinal marl of the Pabdeh Formation in the Bang-estan Anticline. This suggests that the Bangestan Anticline section was situated in a basinal position during the Oligocene. © 2012 E. Schweizerbart'sche Verlagsbuchhandlung Stuttgart Germany.