Geology, mineralogy, geochemistry, and fluid inclusion study of the West of Golestanabad iron oxide-apatite deposit, northeast of Zanjan
Subject Areas :D. Arab Zozani 1 , Hossein Ali Tajeddin 2 , Majid Ghaderi 3
1 -
2 -
3 - Tarbiat Modares University
Keywords: Fluid inclusions, Geochemistry, Magnetite-apatite mineralization, West of Golestanabad, Zanjan.,
Abstract :
The West of Golestanabad deposit is located 13 km northwest of Zanjan, within the Tarom subzone of the Western Alborz-Azerbaijan structural zone. The rocks in the deposit area predominantly consist of an Eocene volcano-pyroclastic sequence of tuff and lava ranging from andesite to trachyandesite in composition intruded by a monzodiorite-monzogabbro subvolcanic intrusive of Upper Eocene-Oligocene age. The intrusive rocks have calc-alkaline affinity and are classified as metaluminous-prealuminous I-type magmas. Magmatism of the area is synorogenic to post-orogenic and related to active continental margin environments. Mineralization at the West of Golestanabad occurs as vein-veinlets, brecciated, massive, and disseminated iron oxide-apatite within the monzodiorite-monzogabbro intrusions. Mineral assemblages of the deposit consist of magnetite, hematite, pyrite, chalcopyrite, chalcocite, covellite, iron hydroxide minerals, apatite, actinolite, tremolite, quartz, epidote, chlorite and sericite. The main alteration minerals are actinolite, quartz, sericite, epidote, and minor sulfide minerals, which are associated with the iron oxide-apatite ores. Similar REE patterns of apatite and magnetite with host rock samples demonstrate a genetic link between the iron oxide-apatite mineralization and monzodiorite-monzogabbro intrusions. Fluid inclusion studies on the apatite indicate homogenization temperatures between 347 and 547°C and salinity from 5.86 to 21.68 wt.% NaCl eq. for the two-phase (LV) inclusions. The study indicates that the main characteristics of the geology and mineralization of the West of Golestanabad deposit are similar to those of the iron oxide- apatite (IOA) deposits.