| This paper mainly studied on ore genesis and ore-control regularity of Chagande’ersi molybdenum deposit, and it analyzed in aspects of ore forming material source of Molybdenite, ore-controlling law, mineralization factor, at last forming mineralization model, then it will benefit for exploration and development of Chagande’ersi molybdenum deposit, also it will provide theoretical guidance among similar geological background in the center and western area of Inner Mongolia.A comprehesive research was carried out on aspects of Geological structure analysis, Ore and Mineral identification, Geochemical data analysis, Geophysical and Geochemical exploration material analysis, Sulfur isotopic analysis, Fluid inclusion temperature analysis, Diagenetic and Metallogenic age analysis, and combined with Computer Analysis Techniques to study.Study found that the molybdenite mineralization age, formed in early Indosinian, was very close to the diagenetic age of K-feldspar granites in early Triassic epoch. Molybdenite ore body was mainly controlled by quartz vein, and closely related with NW-trending quartz vein. Molybdenite ore distributed in quartz vein fissure, greisen vein, fracture of silicified zone, which is different from porphyry molybdenium mine model. Hydrothermal alteration in the mine area is banded distributed, nearly SN trend. Mo is positively related with Pb、Ag、Bi、Cu、Zn、Sb elements, and hydrothermal contains remelting component of crustal source, moreover, it with medium-high temperature and medium-low temperature metallogenic characteristics. Hydrothermal fluid contain medium-high temperature and low salinity fluid in the main term, and medium-low temperature and low salinity fluid in the second term, with rain water joined in later period. The δEu value of normal type quartz of REE distribution curve is close to the δEu value of the crust type and alkaline granite. The δEu value of right deviation type quartz vein and heavy REE depleted quartz vein are close to the δEu value of crust-mental type granite. The sulfur isotope value is close to the value of the acidic rock, and its’source may come from the mixture of remelting magmatic rock and atmospheric water. Hydrogen and oxygen isotope study showed that sample with low water-rock ratio, and the isotopic of water depends on the isotopic value of rock. The low value of hydrogen isotope may caused by the mixing of magmatic hydrothermal and rain-water. It has the formation of Cu、Mo、Au ore potential in this area, and it mainly distributed in the rock contact zone with low-magnetic, low resistance, high polarization characteristics.In a word, the metallogenic source of the deposit may come from the upper mantle and crust remelting magma during early Triassic epoch post-collision activity, and the ore-forming elements are extremely enriched through fractional crystallization. Fissure developed as tectonic movement, late stage hydrothermal of ore-rich migrate upward, and mineralization by filling in the appropriate condition, later mineralization mixed with rain-water. Molybdenite ore body was mainly controlled by quartz vein, and closely related with NW-trending quartz vein. Alteration and mineralization are all with zoning, and forming geophysical and geochemical abnormal zoning, which is located in the rock contact zone with low-magnetic, relatively medium-low resistance, and relatively high polarization characteristics. It belongs to the medium-high temperature, medium-low temperature, and low salinity fluid mineralization, and it is a typical quartz vein-type deposit forming by later stage magmatic hydrothermal. |
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