Biostratigraphy of Kometan Formation in Khashab Well-1, Hamrin Area, Northeastern Iraq.

Abstract

The present study deals with biostratigraphy of the Kometan from the subsurface section of Khashab well No.1, Hamrin area Northeastern Iraq. Lithologically, the studied Kometan Formation are divided into three units. The studied sequences characterized by different ratios of planktonic and benthonic foraminiferal assemblages. Forty eight planktonic species belonging to fifteen genera and 23 benthonic species belonging to fifteen genera have been recognized. Four biozones are recognized based on the stratigraphic distribution of the planktonic foraminiferal assemblages are recognized within the studied Kometan Formation representing an age ranging from Late Turonian-Santonian.These zones are as following from oldest-youngest: 1Marginotruncana sigali Partial range Zone (Part) (Late Turonian). 2Dicarinella primitiva Interval Zone (Early and Middle Coniacian). 3Dicarinella concavata Interval Zone (Late Coniacian-Early Santonian). 4Dicarinella asymetrica Total rang Zone (Santonian).