Biostratigraphic and Lithostratigraphic Study of Fahliyan Formation in Kuh-E-Siah (Arsenjan Area, North-East of Fars Province)

Abstract

Fahliyan Formation is importance in terms of Zagros stratigraphy since it is one of the oil reservoir rocks at the Jurassic-Cretaceous boundary. This rock unit consists of two types of deep and shallow facies in Zagros area. Recognition of bio-zones as well as discontinuity or continuity between the studied formation and the encompassed strata is taken into consideration. In order to study biostratigraphy on Fahliyan Formation, the stratigraphic section of Kuh-e-siah in the northeast of Fars Province was selected. In this section, Fahliyan Formation is measured 345 m consisting of thin to medium-bedded of limestone with the interbeds of sandy and dolomitic limestones. Fahliyan Formation conformably overlies Surmeh formation and underlies the marls of Gadvan formation. Vertical distribution of the identified foraminifers and calcareous algae confirms presence of 3 biozones in the sediments of Fahliyan Formation, as follows: 1) Calpionella alpina zone; 2) Pseudochrysalidina conica zone; 3) Pseudocyclammina lituus-Trocholina sp. assemblage zone. Based on Established biozones, the age of Fahliyan Formation in Kuh-e-Siah section was determined from Berriasian to Late Hauterivian.

Geochemical study of the early cretaceous Fahliyan oil reservoir in the northwest Persian Gulf

“…Multiple major Fahliyan reservoirs have been identified in the NW region of the Persian Gulf (Adabi et al 2010;Abedpour et al 2016;Feghi et al 2012). However, the origin, source rock and maturity of the oil within this formation are only poorly understood.…”

“…(2012) Rock physics modeling The developed model showed that the shale and limestone have various trends but marl was always laid stable between themAbedpour et al (2016) Biostratigraphic & lithostratigraphic analysis Depending on the distribution of recognized algae and foraminifers, only 3 biozones were recognized, such as pseudochrysalidina conica, calpionella alpine, and pseudocyclammina lituus-Trocholina sp. assemblage zones Jamalian and Adabi (2014) Geochemistry and microfacies analysis Fahliyan Formation was build up in a shallow warm-water environment in the age of early Cretaceous; its porosity and original texture were mainly influenced by dissolution, dolomitization and cementation diagenetic processes…”