Updated stratigraphy, tectonics and boundary conditions of the Mawat and Bulfat Ophiolite Complexes, Kurdistan Region, NE-Iraq

Abstract

The Mawat and Bulfat Igneous Complexes are two neighboring areas in the extreme northeastern Iraq near the border with Iran. Each complex has about 250 square kilometers in surface area and their stratigraphic and tectonic settings are nearly identical. These settings are established in the seventieth of the last century and since that time no significant changes are introduced till now although tens of the studies achieved on them. Here we introduce dramatic changes in the stratigraphy and tectonics of the two complexes depending on field mapping, eye witness and correlations in addition to applying petrographical, paleontological and boundary conditional studies. The two igneous complexes are changed to metamorphic core complexes by changing the previous ophiolite to metamorphosed greywackes and volcaniclastic sandstones. Additionally the previous three allochthonous sheets are considered to be autochthonous sedimentary stratigraphic units which include non-metamorphosed greywackes and limestone (Walash-Naoperdan Series) metamorphosed greywackes (previous ophiolite sheet) and metamorphosed Naoperdan Series (previous Gimo thrust Sheet). The deposition timing, source areas and their relation with other units of the Paleocene-Eocene are clarified and their boundaries are changed from tectonic to depositional. These attributes are linked with historical development of Sanandij-Sirjan Zone as the main part of Neo-Tethys sedimentary basin. It is concluded also that these sedimentary rocks are buried deeply during Late Eocene and metamorphosed regionally then uplifted as Core Complex during Pliocene bringing up with them self- Cretaceous units such a Shiranish Formation.