Integrated depositional model of the Carbonate Kirkuk Group of Southern Kurdistan-Iraq

Abstract

The carbonate Kirkuk Group succession hosts major hydrocarbon reserves in the southern Kurdistan-Northen Iraq. This is why investigations into this succession started a long time ago, especially for oil exploration.

In this research numerous microfacies were identified from the Kirkuk Group and interpreted as having been deposited in a ramp setting based on lateral variations of the microfacies; gradual deepening with no evidence of slope break or effective barriers. A depositional model has been generated from the overall palaeoenvironmental interpretations of the microfacies in which the analysed microfacies indicate palaeoenvironments ranging from terrestrial to open marine settings; nine major depositional environmental zones have been identified and correlated with the standard Cenozoic carbonate ramp model. These zones distributed across the ramp setting, dipping southwest, in which zone 1 is a terrestrial deposit; zone 2, 3, 4 and 5 belong to the inner ramp; zone 6, 7 and 8 belong to the middle ramp and zone 9 belong to the outer ramp and basinal settings.

Key words: Kirkuk Group, microfacies, Oligocene, Carbonate, Kurdistan, Iraq.