Author/Authors :
Pour Kiani، Masoud نويسنده Management Group, Kish International Unit, Islamic Azad University, Kish, Iran , , Ahmadi-Khalaji، Ahmad نويسنده Department of Geology, Faculty of Sciences , , Kamali، Zahra نويسنده School of Earth Sciences , , Shafaii Moghadam، Hadi نويسنده School of Earth Sciences ,
Abstract :
The Noorabad-Kermanshah ophiolite is part of Eastern Mediterranean-Zagros-Oman Tethyan ophiolites, that this area is located in south-southwest of the Main Zagros Thrust fault. This ophiolite consists of peridotites, serpentinites and pegmatite gabbros as mantle sequence whereas crustal sequences are composed of locally layered gabbros, isotropic gabbros, sheeted dike complex, basaltic to andesitic lavas and sedimentary rocks (radiolarites and late Cretaceous pelagic limestones). The diabase dikes enriched in LREE relative to HREE elements)La(n)/Yb(n)=1.7-3.3). Also, the andesites are enriched in LREE relative to HREE elements)La (n)/Yb(n)=3.1-5.37) and the pillow lavas are enriched in LILE (Th(n)/La(n)=2.1) while show a depletion in HFSE (Nb(n)/La(n)=0.07-0.2). The Basaltic-andesitic lavas exhibiting mainly calc-alkaline, with minor island-arc tholeiitic affinities, are characterized by enrichment in LILE and LREE and depletion in HFSE. These geochemical characteristics compared with other Tethyan ophiolites along the Bitlis-Zagros suture zone reveal a supra-subduction zone environment for the genesis of the Noorabad-Kermanshah ophiolites.
