Paleocene sequence development in the Iraqi western desert

Abstract EN

The Paleocene succession in the Iraqi Western Desert, represented by Akashat Formation, is developed through six third order cycles.

Local tectonism and eustacy caused the subdivision into several cycles.

The K/T boundary is represented by a transgressive surface; correlated with the major Global Paleocene Transgression.

The Early Paleocene succession was mainly controlled by the eustatic component and the resultant eustatic subsidence.

During the Middle Paleocene; a major transgression had caused the extension of the basin eastward and shows interbedding of basinal-deep-shallow open marin facies reflecting minor relative sea level fluctuation.

The Late Paleocene consists of a retrogradational pattern of deep or basinal facies of the TST bounded by a maximum flooding surface (MFS); this MFS is determined by marls rich with planktonic foraminifera of Late Paleocene age (Globanomalina pseudomanirdii Zone).

This cycle ends up with a characterastic zone of coprolites rich with oysters, Operculina spp., Nummulites deserti, Lenticulina sp., and Late Paleocene planktonic (keeled).