Petrology and geochemistry of Dasht Kuh volcanic rocks in North of Iranshahr, East of Iran flysches terrain

Daryapeyma Hormozi, M; Biabangard, H; Bagheri, S; Bakhshi Mohebi, M.R

doi:10.22071/gsj.2016.40914

Petrology and geochemistry of Dasht Kuh volcanic rocks in North of Iranshahr, East of Iran flysches terrain

Document Type : Original Research Paper

Authors

M Daryapeyma Hormozi ¹

H Biabangard ²

S Bagheri ²

M.R Bakhshi Mohebi ²

¹ M. Sc., Department of Geology, Faculty of Basic Science, University of Sistan & Baluchestan, Zahedan, Iran

² Assistant Professor, Department of Geology, Faculty of Basic Science, University of Sistan & Baluchestan, Zahedan, Iran

10.22071/gsj.2016.40914

Abstract

Dasht Kuh volcanic complex is located to ~75 km to the north of Iranshahr. It consists of two parts: A (main body) and B (the isolated part in the northern Dasht Kuh). Based on the geological maps of the area, the volcanic bodies intruded the flysch type rocks of the East Iran in Cretaceous; the rocks are separated from Eocene conglomerate across a fault zone. The Dasht Kuh volcanic complex essentially consists of basalt, andesite, basaltic andesite and trachybasalt. The main rock-forming minerals are plagioclase, pyroxene, hornblende, and sanidine with dominant porphyritic texture. Minor pyroclastic materials occur in the lower parts of the complex.Samples rocks from of Dasht Kuh in the rare earth elements diagram relative to abundance of these elements in the Chondrite, shows a significant negative slope observed that the samples are enriched in light rare earth elements (LREE) and depletion of heavy earth elements (HREE). Different chemical composition, Tectono-magmatic and origin digrams shows that rocks in these bodies have alkaline nature of mantle origin and were formed in continental volcanic arc. It seems Dasht Kuh volcanic comlex are part of island arc that wide arc from northern Pakistan to Iran that have been separated from their origin by younger tectonic events.

Keywords

Dasht Kuh volcanic complex

Pyroclastic deposits

Trachy basalt

East of Iran flysch zone