S Alipour; B Hosseinzade; Y Rahimsouri
Abstract
Khanik-Gazan titanium potential is located at 82 km northwest of Urmia at the extremity of NW of Sanandaj-Sirjan geological zone. This deposit has formed in the Qazan mafic-ultramafic intrusive complex that intruded into the early Paleozoic sedimentary rocks. It consist ...
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Khanik-Gazan titanium potential is located at 82 km northwest of Urmia at the extremity of NW of Sanandaj-Sirjan geological zone. This deposit has formed in the Qazan mafic-ultramafic intrusive complex that intruded into the early Paleozoic sedimentary rocks. It consist of two general rock units including 1) mafic unit as the main outcrop volume and 2) ultramafic unit in smaller volume. The mafic rock type is gabbro in general formed of medium grained and layered accompanying by anorthosite sill and microgabbro (diabase). Layered mela and meso-gabbro are the main host rocks for titanium mineralisation in the studied area. The main minerals of the host rock included clinopyroxene (mainly augite), and calcic plagioclases. Opaque minerals and rarely olivine and apatite are the minor minerals and tremolite-actinolite, epidote, zoisite, chlorite, albite, sericite and calcite are the secondary minerals. Saussuritization, uralitization, sericitization and chloritization are the main alterations of main silicate minerals. Ilmenite, titanomagnetite, magnetite, and some hematite and pyrrhotite are the main primary opaque ore minerals. Open-space filling textures including granular and exsolution are the major textures of the ore, while, Spherical, martitization, mylonitization are the minor textures. Total abundance of ilmenite, magnetite, titanomagnetite in the studied polished sections ranges between 5 to 12 vol%. Oxide and silicate phases are associated with the host rocks due to the relatively low oxygen fugacity, which don’t occurred in complete separation of the silicate melt from oxide melt. Based on geochemical studies, the primary magma had revealed an alkaline to sub-alkaline (mainly tholeitic trend) series. According to the mineralogical and petrographical evidences and chemical analyses, the Khanik-Qazan ilmenite-titanomagnetite deposit is similar to the low grade apatite- ilmenite–magnetite Kauhajarvi and Lumikangas deposits, in western Finland.
S Alipour; A Abedini; Sh Abdali
Abstract
The Heydar-Abad laterite horizon is located at 65 km south of Urmia, West Azarbaidjan province. This horizon was developed as stratiform bed within the carbonate rocks of the late Permian Ruteh Formation. Based on the petrographical and mineralographical studies,the ores of this horizon contain micro-granular, ...
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The Heydar-Abad laterite horizon is located at 65 km south of Urmia, West Azarbaidjan province. This horizon was developed as stratiform bed within the carbonate rocks of the late Permian Ruteh Formation. Based on the petrographical and mineralographical studies,the ores of this horizon contain micro-granular, fluidal-collomorphic, panidiomorphic-granular, spastoidic, pelitomorphic, nodular, and ooidic textures and have an authigenic origin. According to the mineralogical investigations, the ores of this horizon include minerals such as diaspore, corundum, hematite, magnetite, goethite, rutile, paragonite, margarite, amesite, berthierine, montmorillonite, chlorite, chloritoid, muscovite-illite, quartz, pyrite, anhydrite, calcite, and dolomite. The presence of high quantities of silicate minerals indicates immaturity and poor draining system during the development of this residual horizon. The results of chemical analyses show that Eu and Ce anomalies in the ores are within the ranges of 0.67 to 2.74 and 0.86 to 2.16, respectively. The calculations of values of enrichment factor of elements in two selected profiles reveal that two processes of leaching and fixation are major regulators of concentrations of REEs in ores of this horizon. The results obtained from the mineralogical and geochemical studies show that changes of pH of weathering solution, fluctuations of level of ground-waters, alteration intensity, and function of carbonate bedrocks as a geochemical barrier, adsorption, and scavenging have played an important role in distribution of the rare earth elements (REEs) in this deposit. The correlation coefficients show that the secondary phosphates, rutile and muscovite-illite are potential hosts for REEs in the ore.
