Stratigraphy and Mineralogy of Balambo Formation (Aptian - Cenomanian) near Chomabrok village, Imbrication Zone, Iraqi Kurdistan Region

The stratigraphy and mineralogy of Balambo Formation (Aptian - Cenomanian) in exposed surface section near Chomabrok village the Imbrication zone, northeastern Iraq is studied. 450 meters thick consists thin to medium bedded yellowish-brown, black dark gray limestones, marly with thin- bedded, grayish marl shale, bands cherts abundant nodules lenses. From field observations petrographic studies, formation mainly made from two main lithofacies types; limestone-marl cherty limestone lithofacies. study carbonate rocks deepened on 79 sections demonstrated that carbonates composed micrite ground mass skeletal grains; planktonic some benthic foraminifera, radiolaria, calcisphere, ostracods, pelecypods, larva-ammonoids, small-brachiopods, sponge spicules, echinoid spines, bioclasts. Non-skeletal grains include peloids only. Using extraction method according an assessment foraminiferal assemblages based defined foraminifera assigned age studied Aptian Cenomanian as upper age. results X-ray diffraction (XRD) analysis for bulk selected shale samples suggested presence phyllosilicate calcite, common quartz, moderate Fluorapatite minor dolomite content. Illite dominant clay mineral indicates a hot, arid climate during most Cretaceous period Northeastern Iraq.