Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Mineral Chemistry, Thermobarometry, and Petrogenesis of Igneous Rocks from the Negisan Area, East of Rudbar, Kerman Province, Iran

Articles in Press

Document Type : Original Research Paper

Authors
Mehrnaz Zaifi 1
Gholamreza Ghadami 2
Mohammad Poosti 3
Mohammad Fadaeian 4
1 M.Sc. Student, Department of Geology, University of Hormozgan, Bandar Abbas, Iran
2 Phd of geology group, Faculity of science, University of Hormozgan
3 Associate Professor, Department of Geology, University of Hormozgan, Bandar Abbas, Hormozgan, Iran
4 Assistant Professor, Department of Geology, Payame Noor University, Tehran, Iran
10.22071/gsj.2026.561524.2236
Abstract
The study area lies in the northwestern part of the Dehaj–Sarduiyeh Magmatic Belt within the Urumieh–Dokhtar Magmatic Arc. The volcanic sequence consists of basalt and olivine–basalt with porphyritic to glomeroporphyritic textures, containing major phenocrysts of plagioclase (bytownite–labradorite), clinopyroxene (diopside–augite), and olivine (chrysolite). Integrated petrographic analyses, mineral chemistry, and clinopyroxene-based thermobarometry were employed to constrain the magmatic evolution of these rocks. Clinopyroxene compositions indicate an alkaline affinity and an intraplate tectonomagmatic setting for the parental magma. Thermobarometric results suggest crystallization at temperatures of 1160–1200 °C and pressures of 2–5 kbar (≈7–18 km depth), under high oxygen fugacity and hydrous conditions. Systematic compositional differences between olivine–basalts (less evolved) and basalts (more evolved) reflect fractional crystallization as the dominant magmatic process. However, disequilibrium features such as sieve textures in plagioclase point to an open, dynamic magmatic system where magma mixing also played a significant role. Overall, the magmatism represents post-collisional volcanic activity developed within an extensional tectonic regime.
Keywords
Alkaline basalt, Mineral chemistry, Thermobarometry, Negisan, Dehaj&ndash
Sarduiyeh, Kerman

Subjects

Scientific Quarterly Journal of Geosciences

Articles in Press, Corrected Proof
Available Online from 26 April 2026