New findings in biostratigraphy of the Sarvak and Ilam formations of Abteymour Oil Field (Dezful Embayment)

Abstract

Biostratigraphic studies of the Sarvak and Ilam formations in wells no. 1 and 14 of Abteymour Oil Field led to recognition of six species of foraminifers for the first time from the two mentioned formations. In this research, the species of Fischerina carinata and Spiroloculina cenomana in the Sarvak Formation and the species of Palaeosigmoilopsis apenninica and Sigmomassilina ottadunensis in the Sarvak and Ilam formations belong to suborder of MILIOLINA Delage and Herouard, 1896 and the species Rotorbinella sp. nov. in the Sarvak Formation and Pararotalia boixae belong to suborder of ROTAIINA Delage and Herouard, 1896 were identified and described in the Sarvak and Ilam formations. These species have not been reported from Sarvak and Ilam formations so far. Based on the identified fauna, the age of the Sarvak Formation with a thickness of 812.98 and 238 meters in wells no. 1 and 14 respectively are Cenomanian-Turonian and age of the Ilam Formation with a thicknesses of 151.7 and 136 meters in wells no. 1 and 14 respectively are Santonian- Campanian?.