Geochemistry and Petrogenesis of Oligo-Miocene Plutonic Rock Bodies, Northwest of Shahr-e-Babak, Kerman Province, Iran

Ghadami, Gh; Moradiane Shahre Babaki, A; Mortazavi, S.M

doi:10.22071/gsj.2015.42905

Geochemistry and Petrogenesis of Oligo-Miocene Plutonic Rock Bodies, Northwest of Shahr-e-Babak, Kerman Province, Iran

Document Type : Original Research Paper

Authors

Gh Ghadami ¹

A Moradiane Shahre Babaki ²

S.M Mortazavi ¹

¹ Assistant Professor, Department of Geology, Hormozgan University, Hormozgan, Iran

² Associate Professor, Department of Geology, Shahid Bahonar University, Kerman, Iran

10.22071/gsj.2015.42905

Abstract

More than 20 tonalitic to granodioritic plutonic domes, Oligo-Miocene in age, have intruded into the older volcanic rocks, in southeast of Urumieh- Dokhtar Magmatic Belt, northwest of Shahr-e-Babak. These rocks have granoporphyritic texture and consist of Phenocrysts of plagioclase, amphiboles and biotites. The geochemical data show calc-alkaline affinities of these rocks , which formed in volcanic arc (I type) of an active continental margin. These data also show LILE and LREE enriched normalized multi-element patterns, and depleted of HFSE (Nb, Ta and Ti). Primitive mantle-normalized REE patterns display a dramatic decrease from LREE to HREE without any Eu anomaly. They have higher SiO₂, Al₂O₃ and Sr content and Sr/Y and La/Yb ratios and lower MgO, Y and Yb contents than the normal calc-alkaline rocks, which reveal their adakitic characteristics. The high content of Sr, LREE enrichments, absente of Eu anomaly, HREE depletion, Y and Yb depletion pattern suggest the existence of garnet, amphibole and absence of plagioclase in the source rocks. Our data suggest that the plutons produced by partial melting of amphibole-eclogite or garnet-amphibolite, due to the subduction of Neotethys oceanic slab under the Central Iran continent.

Keywords

Tonalite

Granodiorite

Neo-Tethys

Adakite

Urumieh-Dokhtar