--> Abstract: Sequence Stratigraphy and Basin Modeling of the Eocene Succession from Kurdistan Region, Northeastern Iraq, by Fadhil Ahmed Ameen; #90077 (2008)

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Sequence Stratigraphy and Basin Modeling of the Eocene Succession from Kurdistan Region, Northeastern Iraq

Fadhil Ahmed Ameen
University of Sulaimaniya, Iraq
[email protected]

The Eocene strata of the Zagros segment in Sulaimaniya area, northeastern Iraq, have been interpreted to contain two third-order sequences. The oldest Ypresian third-order sequence is represented by transgressive and highstand (TST and HST) system tracts and reflects syn-sedimentary tectonic activities, mostly resembled by Sinjar formation. It is divided into two fourth-order cycles each consisting of parasequence sets. The overlying Lutetian third-order sequence consists of carbonates deposited in a ramp setting. It is also divided into two fourth-order sequences that consist of highly permeable and porous carbonates. The red molasses of the Gercus Formation indicate a lowstand fan deposit and a probably fifth-order cycle. The youngest Eocene third-order sequence is represented by the evaporites and carbonates of the Sagerma Formation, and probably reflects climatic changes. Remnants of the foreland basin, located in front of the Cretaceous accretionary complex, played an important role in the paleo-configuration of the Eocene ramp-rimmed shelf basin. This is reflected by a stratigraphic gap and unconformity (sequence boundary type 1) at the Paleocene/Eocene boundary. The Ypresian basin evolved from a shallow-marine ramp, to shoal and mixed carbonates–siliciclastics sequences. In contrast, the Lutetian basin started as a Nummulitic algal carbonates ramp that underwent a catch-up phase followed by a rapid give-up stage. The Nummulitic carbonates are very thick, and contain good hydrocarbon reservoirs. The carbonate ramp is overlain by thin Gercus red clastics, whereas in the southern sector it is overlain by lagoonal carbonates and evaporites. This paleogeography may reflect the reactivation of a strike-slip fault that changed the ramp basin to rimmed shelf. Forming a very thick, permeable, Nummulitic reservoir, and reflecting the early phase of the continent-continent collision between the Arabian and Iranian plates during the Middle Eocene.


AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain