Calcareous Nannofossil Biostratigraphy of Pabdeh Formation at Gurpi Anticline

Ahifar, A; Kani, A; Amiri Bakhtiar, H

doi:10.22071/gsj.2015.42301

Calcareous Nannofossil Biostratigraphy of Pabdeh Formation at Gurpi Anticline

Document Type : Original Research Paper

Authors

A Ahifar ¹

A Kani ²

H Amiri Bakhtiar ³

¹ Ph.D. Student, Faculty of Earth Science, Shahid Beheshti University, Tehran, Iran

² Assistant Professor, Faculty of Earth Science, Shahid Beheshti University, Tehran, Iran

³ Ph.D., National Iranian Southern Oil-Field Company (NISOC), Ahwaz, Iran

10.22071/gsj.2015.42301

Abstract

Pabdeh Formation has been investigated in three sections viz. the Type Section, Tang-e Hatti and the northern limb of Gurpi Anticline within the ZagrosSedimentaryBasin with emphasis on calcareous nannofossils. Study of microscope slides prepared from the 1508 collected samples resulted in determination of 256 species belonging to 59 genera from 22 families of nannofossils and biostratigraphic classification was carried out based on their stratigraphic distribution. According to Martini (1971) zonal scheme, presence of NP4-NP23 nannofossil zones at the Type Section, and NP5-NP23 nannofossil zones at both Tang-e Hatti and northern limb sections have been ascertained thus indicating ‌‌Early Paleocene to Early Oligocene age for the Pabdeh Formation at these three localities. Calcareous nannofossil assemblages reveal sedimentation of Pabdeh Formation occurred in an oligotrophic, warm water environment during Paleocene-Eocene which was later on replaced by a relatively cooler water condition in Oligocene times.

Keywords

Calcareous Nannofossil

Pabdeh Formation

Gurpi Anticline

Zagros