Geological characteristics and molybdenite Re-Os isotopic dating of Qianfanling quartz-vein Mo deposit in Songxian County,western Henan Province
Geological characteristics and molybdenite Re-Os isotopic dating of Qianfanling quartz-vein Mo deposit in Songxian County,western Henan Province
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作者：
Li Yong
The Qianfanling Mo deposit located in the Xiong'ershan-Waifangshan area is a newly discovered quartz-vein type Mo deposit in the East Qinling molybdenum belt. The host rocks of the deposit are Paleoproterozoic andesitic volcanic rocks of the Xiong'er Group. The orebodies occur as molybdenite-quartz veins and the major ore type is quartz-vein type. The main metallic minerals are molybdenite and pyrite. Quartz is the most abundant gangue mineral,and other gangue minerals include calcite and fluorite. The main alteration types of wall rocks are silicification,K-felsparization and propylitization etc. Six molybdenite-bearing samples were selected for precise Re-Os dating,which yielded model ages ranging from 233.3±3.3Ma to 248.2±3.5Ma and an isochron age of 239±13Ma. The deposit was formed in the Middle-Triassic. The Qianfanling Mo deposit formed in the late stage of collision of North China and Yangtzi cratons. Local shear and extension setting formed by a great regional collision are the favorable factors for the formation of the ore-controlling faults and migration of the ore-forming fluid. Many vein-type Mo deposits have been found in Songxian County,and they are likely to be formed at the same time (Triassic). These quartz-vein type Mo deposits constitute the vein-type Mo deposit field in Songxian County between the Xiong'ershan and Waifangshan area.
