Biostratigraphy of the basal part of the Dalan Formation at Chal-I-Sheh section, High Zagros

The lower part of the Dalan Formation in Chali-I-Sheh section, High Zagros has been studiedin regard to foraminiferal fauna composition. It composed of alternated sandstone and limestone in the lowermost portion and grade chiefly into carbonate upward. These carbonates contain low diversity of small foraminifers and small fusulinids that do not yield an age older than Guadalupian. It can be assumed that the deposition of Dalan Formation in this section was slightly later than that of Il-e Beyk section in Zard Kuh area. Although Lithologic changes at the base of the Dalan Formation in the Chal-I-Sheh section is transitional, but the lack of diagnostic Kubergandian foraminifera is indicative of a greater hiatus at the lower part of the Dalan Formation in the Chalish-I-Sheh section compared with Il-e Beyk section in the Zard Kuh area.