Mineral chemistry and geothermobarometry of pyroxenes in East Harzburgites of Hajiabad (Hormozgan province): Implication to petrogenetic evolution and tectonomagmatic setting

Authors

1 Department of Geology, faculty of natural sciences, University of Tabriz,. Iran,

2 Department of Geology, faculty of basic sciences. Velayat university, Iranshahr, Sistan and Bluchestan. Iran.

3 Department of Geology, Faculty of Basic Sciences, Islamic Azad University of Zarand, Kerman, Iran.

Abstract

Mantle peridotites form an important part of Esfandah-Hajiabad ophiolitic belt on the southeast of Sanandaj-Sirjan zone. The East Harzburgites of Hajiabad, having minerals such as olivine, orthopyroxene, and clinopyroxene, are the main unit among this set of ultramafic rocks that do not have obvious layering and are observed as masses. The orientation of minerals, recrystallization and different generations of minerals indicate that these rocks are prouduced in the upper mantle and implacement in the crustal environment. Mineral chemistry of pyroxene in harzburgites show that in these rocks, orthopyroxenes are located in the enstatite range and clinopyroxenes are located in the diopside range. Based on thermometric and barometric studies on pyroxene crystals in harzburgites, the equilibrium temperature is around 1342.11 ͦ C and the crystallization pressure is around 14.12 kb, which corresponds to the range of spinel peridotite. Based on geochemical and tectonic studies, the harzburgites in the east of Hajiabad were formed in the range of abyssal peridotites towards a supersubduction zone, probably similar to back-arc basin with about 12% partialmelting. The behavior of rare earth elements associated with the rock samples of the study area also proves the partialmelting and metasomatism processes that occurred during the formation of these rocks.

Keywords



Articles in Press, Accepted Manuscript
Available Online from 09 December 2024
  • Receive Date: 20 August 2024
  • Revise Date: 16 November 2024
  • Accept Date: 09 December 2024