Stratigraphy and Facies Analysis of the Govanda Formation from Western Zagros, Kurdistan Region, Northeastern Iraq

A part of the Govanda Formation is studied in five outcrops from northeastern Iraq near the Iraqi-Iranian borders. It consists of polygenic conglomerates, detrital limestones (conglomeratic limestone), and highly fossiliferous limestones of reeffore-reef facies with occasional interbedding of terrigenous sediments. Tectonically, the formation is important for its location in the very active Sanandij-Sirjan (Suture) Zone and for its deposition in Middle Miocene, which was assigned previously as an age of continental-continental colliding of Zagros Fold-Thrust belt. Additionally, it is overlaying different rocks units of pre-Miocene, especially resting on the Qulqula Radiolarian Formation in an angular unconformity relationship. The high-energy and tectonically active shallow and normalmarine environment is inferred from many facies such as coral framestone, pelecypod floatstone facies, coral and lithoclast rudstone, coral bufflestone, stromatolite bindstone, foraminifera and red algal bioclastic packstone–wackstone, reworked foraminiferal-lithoclast grainstoneKamal H. Karim et al., 70 packstone, lithoclast grainstone and terrigenous lime sandstone. The environment of the formation was high energy, shallow and normalmarine sea, which consists of fore-reef, reef and back-reef. The tectonic and paleogeographic relations of the formation are discussed in terms of facies and boundary condition. It is confirmed that the Sanandij-Sirjan Zone was subjected to an extension not compression (continentalcontinental colliding), as cited in some studies. The richness of the basin and fauna indicates that it was connected to Indian Ocean and Mediterranean Sea.