Author/Authors :
Moslempour، Mohammad Elyas نويسنده Department of Geology, Zahedan Branch, Islamic Azad University, Zahedan, Iran Moslempour, Mohammad Elyas , Khalatbari-Jafari، Morteza نويسنده Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran Khalatbari-Jafari, Morteza , Dabiri، Rahim نويسنده Department of Geology, Mashhad Branch, Islamic Azad University, Mashhad, Iran Dabiri, Rahim , Shahdadi، Sara نويسنده Department of Geology, Zahedan Branch, Islamic Azad University, Zahedan, Iran Shahdadi, Sara
Abstract :
Nosrat-Abad ophiolitic extrusive sequence, located in the Sistan Suture Zone, in south eastern Iran. The extrusive sequence, contains
pillow lava, sheet flow and related volcanic-clastic breccias which have undergone low-grade metamorphism. This association shows
calc alkaline to tholeiitic affinities. Interpretation of the geochemical data and behavior of the elements in different diagrams reveals
two distinct domains in the Nosrat-abad ophiolitic extrusive sequence. The sheet flows are depleted in HFSE similar to those of SSZ.
However, the enrichment of the pillow lavas in LILE could be attributed to an enriched mantle source or melting of metasomatized
sediments above the subducted slab. It appears that two subduction components (fluids-melt), caused the diversity seen in the
chemical composition of the study rocks. The MORB to subduction chemical characteristics of the Nosrat-Abad ophiolitic extrusive
sequence could be explained by a shift in the tectonic settings from the mid-ocean ridge to the marginal basin in Sistan during the
Late Cretaceous period.
