تقييم السحنات الدقيقة لتكوين قره جيني (الترياسي المتأخر)‎ و سيناريو تطور حوضه الرسوبي في شمالي و شمال غربي العراق

Abstract EN

The present study focuses on the evaluation for microfacies of Kurra Chine Formation (Late Triassic) in four oil wells: Jabal Kand (Kd-1), Ain Zalah (AZ-29), Butmah (Bm-15) and Alan (Aa-2).

The formation is consisting of alternation of dark brown and black limestones, dolomite, anhydrite and ribbons of shale.

Ten carbonate microfacies are distinguished based on fauna content, lithology, and texture as well as anhydrite and shale facies.

The results of all microfacies and lithofacies, the Kurra Chine Formation was deposited under wide spectrum of depositional environments within carbonate ramp setting.

Inner ramp deposits are more common in the formation's successions in Ain Zalah and Alan wells.

While middle and outer ramp deposits are clearly showing in Butmah and Jabal Kand wells, as well as inner ramp deposits.

According to unconformity surfaces, successions of formation were divided into three stratigraphic units, started in late Triassic (Early Carnian) age and ended in Early Jurassic.

Thickness of these units are various in sections study which is caused by the differentiation of tectonic evidence and rate of subsidence.