Microfacies Analysis and depositional environment of Pila Spi Formation in selected sections , Northern Iraq

Authors

  • Rhman Fakhir Mutar, Hamid Ali Ahmed Alsultan

Abstract

This study involves reconsidering the microfacies , Petrographic and depositional environment of the PilaSpi formation in northern Iraq at the governments of Erbil and Dohuk. To achieve this We studied the Pila Spi Formation at three outcrops (Shaklawa, Zawita, and Sendor sections) andcollecting two hundred and thirty-five samples, and describing all units of the formation.Field studies showing the formation of Pila Spi consist of well-bedded, thick-bedded, massive, and dolomitic limestone and marly limestone and chalky limestone with thin marl beds and effected by dolomitization.From the bottom, the contact PilaSpiFormation with Gercus Formation (Middle Eocene) and basal conglomerate is based on contact (thickness between 10-12 m) and from the top the contact Pila Spi Formation with Miocene rocks represented by FathaFormation.Because the disappearance of Oligocene sediments the boundaries between Pila Spi Formation and Fatha Formation are unconformablerepresented by (sequence boundary type -1).The Petrographic study showing the formation of Pila Spi contained both skeletal and non-skeletal grains and was performed by diagenetic processes such as micritization, cementation, dissolution, and neomorphism.Microfacies analysis shows the Pila Spi Formation recognition of eight microfacies are:(Fossiliferous Packstone,Fossiliferous Wackestone -Floatstone,Bioclastic Packstone,Bioclastic Peloidal Packstone,Bioclastic Wackestone,Lime Mudstone,Sandy Lime Mudstone,Intraclastic Wackestone Microfacies )which are interpreted and grouped into three facies associations are:( Back reef association,Lagoon association,and Intertidal association).

Published

2020-10-16

Issue

Section

Articles