Large Tertiary Foraminiferal Biostratigraphy, Kirthar Province, Sind, Pakistan: ABSTRACT

Abstract

Large foraminifera of Pakistan are chronostratigraphically diagnostic and are the basis for stratigraphic correlation of marine Tertiary carbonate deposits. The sedimentary deposits of Pakistan are divided into three basins, among which the carbonate deposits of the lower Indus basin are very rich in large foraminifera. The lower Indus basin is divided into Sulaiman and Kirthar provinces. The Tertiary deposits of Kirthar province are mainly carbonate with intercalation of argillaceous sediments, designated to Lakhra, Laki, Kirthar, Nari, and Gaj formations, and range in age from Paleocene to early Miocene. The large foraminifera of these deposits are divided into ten distinct foraminiferal zones. These are: (1) Lakra Formation, characterized by Nummulites muttalii zone of late Paleocene age; (2) Laki Formation, characterized by Assilina granulosa zone of early Eocene age; (3) Kirthar Formation (4) zone, characterized by Nummulites beaumonti zone (middle Eocene), N. pengaroensis zone (late Eocene), N. fichteli zone (early Oligocene), and N. fichteli/Lepidocyclina (E) dilatata zone (middle Oligocene); (4) Nari Formation (3 zones), N. fichteli, N. fichteli/Lepidocyclina (E) dilatata zone, and L. (E) dilatata zone (of early, middle, late Oligocene respectively); and (5) Gaj Formation, characterized by Miogypsina gunteri and M. thecideaeformis zones (Aquitanian and Burdigalian, early Miocene). The foraminifera are mostly restricted to their respective zones. Post-early Miocene rocks of Kirthar province, Sind, Pakistan, are nonmarine and devoid of foraminifera. /P> End_of_Article - Last_Page 591------------