Geochronology of the Xiaodonggou Porphyry Mo Deposit in Northern Margin of North China Craton |
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Authors: | Qingdong Zeng Jianming Liu Feng Qin Zuolun Zhang |
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Institution: | Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China |
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Abstract: | The Xiaodonggou porphyry Mo deposit is located in the Mesozoic calc-alkaline Xiaodonggou granitoid within a Palaeozoic fold zone of northern China. The mineralization mainly occurred in an area of 0.54 km2 at the south-eastern part of the Xiaodonggou granitoid. The mineralization includes disseminated molybdenite, pyrite, chalcopyrite, magnetite and pyrrhotite and stockwork quartz-sulfide veins. A molybdenite-rich inner core is surrounded by a concentric zone of the sulfide mineral assemblage of pyrite, galena and sphalerite. Intense potassic alteration is overprinted by sericitization and silicification in the mineralized zone. SHRIMP U-Pb data of zircon indicate that the granitoid crystallized at 142 ± 2 Ma (2σ). Re–Os age dating for six molybdenite samples from underground galleries of the deposit constrains the age of porphyry-style Mo mineralization to be 138.1 ± 2.8 Ma (2σ). These data suggest that porphyry-style mineralization was associated with the Xiaodonggou granitoid intrusion and support an Early Cretaceous porphyry-type metallogenic epoch along the northern margin of North China Craton. |
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Keywords: | molybdenite northern margin of North China craton Re–Os dating SHRIMP U–Pb dating Xiaodonggou porphyry Mo deposit |
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