The new evidence of Albian - Cenomanian boundary Biostratigraphy for first time from Iran

The Sarvak Formation in Tang – e – Chenarbashi with 712 meters thickness encompasses Albian - Cenomanian planktonic foraminifera. In the studied section, surveying the Albian – Cenomanian boundary is indicated that Rotalipora appeninica Zone not be recognized. Paracostellagerina libyca can be to consider as a marker for Albian – Cenomanian boundary, absence of the Albian marker foraminifera permit us to consider the first occurrence of this species as the begining of Cenomanian. Also Favosella voloshinae, Paracostellagerina libyca are report for first time from Iran.