Petrology, geochemistry, and tectonomagmatic setting of volcanic rocks of the Hormuz and the Gachin salt domes (Hormozgan Province, Iran)

Abstract

The Hormuz and the Gachin salt domes are located in the south of Bandar Abbas, the Hormozgan Province, in Zagros Structure Zone. The domes are dominated by andesite, trachy-andesite, basalt, dacite, and rhyolite belonging to Permian to Triassic age. Based on geochemical evidence, these rocks are calc-alkaline originated in orogenic setting related to subduction environment. The presence of oxide minerals (hematite and magnetite) in the volcanic rocks of the domes reflect oxidization conditions and high oxygen activity during their formation. Negative TNT and high LREE/HREE anomalies along with positive Pb anomalies and low Nb/U ratios (0.48 to 14.6), as well as tectonomagmatic diagrams indicate that the studied rocks are magmatic products of primary mantle origin, which has been metasomatized by continental crustal rocks. High Ba/Nb values, low Sr and Zr/Y>3 ratio along with geochemical diagrams, confirm the characteristics of arc magmas related to the formation of the rocks under study in a subduction environment.

Keywords

• iran
• bandar abbas
• hormuz
• gachin
• salt dome
• volcanic rocks
• geochemistry