Biostratigraphy of the Pabdeh Formation in the Parsi Oil Field (Dezful Embayment, South-West Iran)

• Main Authors: Masume Sabokro, Mohammad Vahidinia, Mohammed Hussain Adabi, Nasrin Hadavandkhani
• Format: Article in Journal/Newspaper
• Language: Persian
• Published: University of Isfahan 2021
• Subjects: pabdeh formation; paleocene; oligocene; dezful embayment; parsi oil field; Stratigraphy; QE640-699; Parsi; Planktonic foraminifera
• Online Access: https://doi.org/10.22108/jssr.2021.25496; https://doaj.org/article/405adf20d89c4a3babe1a2f90308f1b4

AbstractIn order to study biostratigraphy and the determination of biozonation in the Pabdeh Formation based on the new planktonic foraminifera biozonation in the Tethys region, one subsurface section in well 1 of the Parsi Oil Field was selected in the southern Dezful Embayment. Based on this study, a biostratigraphic study of 320 thin sections from well 1 of Parsi Oil Field has been carried out. The Pabdeh Formation with a thickness of 404 m consists mainly of shales, marls, argillaceous limestones, and cherty limestone. The lower boundary of the Pabdeh Formation with the Gurpi Formation is unconformable and the upper boundary with the Asmari Formation is conformable. Biostratigraphic studies led to the recognition of 25 genera and 75 species of planktonic foraminifera and then 19 biozones equivalent to the new biozone of Wade et al. (2011) in the Tethys region. These identified biozones include three biozones in the Paleocene, 11 biozones in the Eocene and five biozones in the Oligocene in the studied section in well 1 of Parsi Oil Field and are well correlated with some biozones in the Tethys region. Based on the identified biozones and fossil contents, the age of the Pabdeh Formation is Middle Paleocene (Selandian)–Late Oligocene (Chattian). Keywords: Pabdeh Formation; Paleocene; Oligocene; Dezful Embayment; Parsi Oil Field IntroductionThe Pabdeh Formation as a hydrocarbon source rock is widespread in the Zagros Basin. The type section of the Pabdeh Formation is located in Tange Pabdeh (North of Lali Oil Field) with a thickness of about 800 meters of shales and purple marls, grey shales, layers of argillaceous limestone and sometimes cherty limestones. It contains well-preserved foraminifera that gradually reaches the limestone of the Asmari Formation and spreads in the southwest of Lorestan, Khuzestan, and Fars provinces (Motiei 1995).Most of the biostratigraphic studies of the Pabdeh Formation in the Dezful Embayment are based on biozones (James and Wynd 1965) which are local and have not the capability ...