R. Mohamadi; M.H., Emami; M. Vosoghiabedi
Abstract
The area is located about 230 km of southwest of Tehran. Based of geological observations, the plutonic rocks in the area consist of Neogene (Miocene) alkaline gabbro , gabbrodiorite, locogabbro and diabase . The Oligo - Miocene calc-alkaline extrusive rocks are dacite - ryodacite , andesite trachyandesite ...
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The area is located about 230 km of southwest of Tehran. Based of geological observations, the plutonic rocks in the area consist of Neogene (Miocene) alkaline gabbro , gabbrodiorite, locogabbro and diabase . The Oligo - Miocene calc-alkaline extrusive rocks are dacite - ryodacite , andesite trachyandesite , hornblendandesite , basaltic andesite and trachybasalt .Studing on isotopic analyses of Nd and Sr indicate that surveyed area were contaminated with crustal rocks of Sialic composition . In isotopy geochemical studies, The Andesite samples are plotted in the limit of BSE; however, it seems that mantling rocks besides being settled in crust (esp. the upper continental crust) have been contaminated with in. The combination of BSE towards enrichment, from the proportion of 87Sr/86Sr has shifted; a sample of rocks shows this position. Spider diagrams related to trace elements of plutonic samples which are used for identifying the tectonic setting show intrusives are in the extensive regime; while the lavas don’t have a steady trend and are similar to subduction zones. This shows that the intrusives of the the investigated area are different genesis from the southern volcanic rocks.
