الملخص

AbstractThe microfacies were identified within the Jaddala Formation in wells (Ja_40, K_243 and K_411) in northeastern Iraq and from the petrographic study it was found that most of the skeletal granules consist of planktonic foraminifra such as ( Globigerina, Globorotalia, Acarinina and Subbotina ). benthonic foraminifra is low, while non-skeletal granules are limited to quartz and phosphate grains, and the groundmass is mainly brown to light micrite. The lithology affected by Diagenetic processes such as compression, cementation, dissolution, recrystallization, and Authigenic minerals such as pyrite. Based on the petrographic study, the form a torn is divided three main Microfacies were identified Lime Mudstone Microfacies (LMJ), Lim Wackstone Microfacies (LWJ) and Lime Packstone Microfacies (LPJ) which was divided into two secondary Submicrofacies planktonic foraminiferal Lime Packstone Submicrofacies (LPJ1) and Bioclastic Lime Packstone Submicrofacies (LPJ2). The depositional environment of the formation was determined depending on the Microfacies content of the fossils planktonic foraminifra and benthonic foraminifra as well as its comparison with the standard Microfacies. Three main environments for the sedimentation of Jaddala Formation were distinguished depending on the classification of the environments set by (Flugel, 2004): (Toe_ of_ Slope, Deep Shelf and Deep Sea). This difference in environments is caused by a difference in the topography of the sedimentary basin.