Relations between Deep and Shallow Stratigraphic Units of Northern Iraq during Cretaceous

The study area includes sulaimani, erbil and dohuk governorates where cretaceous rocks are well exposed in the high foldedzone of north and northeastern iraq. this area is part of the northwestern boundary of the arabian platform near the iranian border.in these governorates, the study tries to clarify the relationship between deep and shallow stratigraphic units (formation or facies)during the cretaceous period. the results of the present study are mainly dependant on the field lateral tracing of the lithologicchanges and paleontological evidence for indicating the new age termination of the units. the results showen are a generalized andsimple model of temporal and special relations between cretaceous deep and shallow water formations. the balambo (kazhdumi iniran), kometan (ilam), shiranish-tanjero (gurpi) formations (as deep facies) are indicated as lateral equivalents of shallow facies ofqamchuqa (sarvak and dariyian), bekhme (has no equivalent in iran yet) and aqra formation (seymare or tarbur) respectively. onthe model, the transition zone is indicated where the deep facies, from the southeast, change to shallow ones in the northwest. theshallow facies consist of coarse grain limestone with fossils, skeletons, bioclasts and intraclasts. the deep facieses are fine grainpelagic limestone with microfossils (panktonic forams and nanofossils) whiles the transitional facies (zones) generally consist of amixture of the two as interfigering relation between the deep and shallow facies. as the changes of the lithology of transitional zonesare relatively sudden, they are not designated as formations and not defined previously.