Petrogenesis of Kuh e-Dom granitoid intrusion, NE Ardestan


The Kuh e-Dom intrusion is part of Urumieh-Dokhtar magmatism in Central Iran Zone. These rocks range from acidic (granodiorite, monzogranite, quartz monzonite) to intermediate (diorite, quartz diorite, monzodiorite and quartz monzodiorite) igneous rocks. The intermediate rocks occur as bands surrounding northern, southern and eastern margins of the acidic rocks. Based on field, petrographic and geochemical studies, Kuh e-Dom intrusion is I type, high potassium calc-alkaline and metaluminous. Chondrite and primitive mantle normalized trace element patterns for most of the sample show enrichment in LREE and LILE and pronounced negative anomalies in Eu, Ba, Nb, Ti, P and Sr. Such geochemical characteristics are typical of magmatism at active continental margin. High Potassium (~4.8%) and La (24 ppm) contents and enrichments in LILE and Pb along with negative HFSE and Ba anomalies indicate that the magma was probably generated by partial melting of lower crust.