نویسندگان
1 دانشکده علوم پایه، دانشگاه بوعلی سینا، 6517838695، همدان
2 استاد گروه زمین شناسی، دانشگاه بوعلی سینا همدان
3 انستیتوی زمینشناسی، آکادمی علوم روسیه
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Sofiewand manganese deposit is 15 km southwest Harsin and 3 km from the Sofiewand village in the Zagros-Trusted and ophiolite zone of Kermanshah. This deposit has been deposited as a layer-vein (syngenetic-epigenetic) along with radiolaritic chert in the Triassic/Jurassic radiolarite sub-zone of Kermanshah. Due to active tectonics in the area, the outcrops of manganese deposits have folded, interrupted and tectonized. The main host rocks are limestone and radiolarian chert. On the basis of mineralographical studies and X-ray diffraction (XRD) analysis and SEM results, most important manganese minerals in the Sofiewand Mn deposit consists of pyrolusite, braunite, hollandite, romanechite, and mangonosite and quartz is the most common gangue mineral. According to chemistry of the major elements, Al2O3 content in vein-veinlets ore ranges from 0.22 to 2.21 wt.% (ave., 1.21) and in banded ore from 1.14 to 2.45 wt.% (ave., 1.79), and MnO in vein-veinlets ore ranges from 38.75 to 71.73 wt.% (ave., 55.24) and in banded ore from 4.85 to 10.54 wt.% (ave., 7.69). The trace element diagrams all indicate the low ore content of elements such as Ni, Cu, and Co, which confirm the location of the deposit in the area of hydrothermal deposits on the diagrams. Co / Ni, Co / Zn, LREE / HREE, La / Ce ratios, enrichment of LREE elements to HREE elements and negative Ce anomaly also indicate the role of mineralizing hydrothermal fluid in this deposit. The Mn/Fe ratio in vein-veinlets ore ranges from 57.80 to 129.87 (ave., 94) and in banded ore from 3.33 to 6.91 (ave., 5), that indicate a relatively strong separation of iron and manganese during transport, and thus it may be concluded that this ore has marine hydrothermal genesis. The distribution pattern of REE for this deposit is very consistent with the distribution pattern of REE in hydrothermal deposits.
کلیدواژهها [English]
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