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Tectonostratigraphic Overview of the Zagros Suture Zone, Kurdistan, NE Iraq

Al-Qayim, Basim *1; Ibrahim, Azad 2; Koyi, Hemin 3
(1) Department of Geology, Sulaimani University, Sulaimaniah, Iraq. (2) Department of Geology, Sulaimani University, Sulaimaniah, Iraq. (3) Department of Earth Sciences, Uppsala University, Uppsala, Sweden.

The northwestern segment of the Zagros fold-thrust belt of the Kurdistan Region of NE Iraq includes a narrow complex suture zone. It represents a stacking of allochthonous Tethyan Triassic- to -Eocene thrust blocks, and bounded by two major tectonic boundaries; the Zagros main reverse fault (ZMRF) from northeast, and the Zagros thrust front (ZTF) to the southwest.

Field cross-examination, petrographic analysis, facies interpretation and lithostratigraphic correlation of these sheets along four field traverses, reveal some interesting links and associations related to their origin and tectonic evolution.

The origin of these sheets is interpreted as follow (from older to younger and from higher to lower): the Triassic Avroman Limestone block represents an isolated carbonate platform rifted off the Afro-Arabian margin; the Jurassic carbonate imbricates are an exhumed carbonates slices of the Chia Gara Formation of the Afro-Arabian margin, the Jurassic-Cretaceous radiolarian chert, limestone, and shale of the Qulqula Group is emplaced as a Tethyan radiolarite , the sedimentary-volcanic units of the Qulqula Group are part of a sedimentary mélange suites, the Mawat and Penjween ultramafic complexes are obducted ophiolite slivers, and the Tertiary volcano-sedimentary sequence of the Walash Group is part of the fore-arc flysch basin.

The stacking pattern and tectonic associations of these blocks indicate that they were evolved upon the closure of the Neotethys and the progression of the Zagros orogenic belt. A tectonic scenario is proposed to constrain the history and evolution of the Zagros suture zone in the studied area.

 

AAPG Search and Discovery Article #90141©2012, GEO-2012, 10th Middle East Geosciences Conference and Exhibition, 4-7 March 2012, Manama, Bahrain