Xintian polymetallie deposit is a hydrothermal vein type Cu-Mo deposit. Analysis on Re-Os isotopic dating for the molybdenite from this deposit is undertaken to determine metallogenic epoch and dynamics setting of the...Xintian polymetallie deposit is a hydrothermal vein type Cu-Mo deposit. Analysis on Re-Os isotopic dating for the molybdenite from this deposit is undertaken to determine metallogenic epoch and dynamics setting of the deposit. Re-Os isotopic dating for the molybdenite yields model ages ranging from 123.9 ± 1.9 Ma to 124.7 ± 1.8 Ma, with a weighted mean age of 123.4 ±0.81 Ma, and an isochron age of 127 ± 16 Ma, MSWD = 0.25, indicating that the metallization was at late Yanshanian. The content of Re in molybdenite is （330.1 ±4.0-367.9 ± 3.1 ） xl0^-6, which demonstrates mantle derived metallogenic sources. Integrating the region-al tectonic evolution and the metallogenic characteristics of other contemporaneous Cu-Mo deposits in the re-gion, it is suggested that the Cu-Mo mineralization of this deposit occurred in an active epieontinental environ-ment under lithospheric extension resulted from the subduction of the Izanagi plate to the Paleo-Asia continental margin at late Yanshanian. The Mantle wedge was partially melted with large amount of metallogenic elements dissolved in it. Under the favorable conditions of crust-mantle interaction, large-scale magmatic activity turns out to be the important mechanism of the mineralization of many Cu-Mo deposits in the Xiaoxingan Range-Zhangguangcai Mountain metallogenic belt, including the Xintian Cu-Mo polymetallic deposit.展开更多
基金Supported by Project of China Geological Survey(No.12120113098300)
文摘Xintian polymetallie deposit is a hydrothermal vein type Cu-Mo deposit. Analysis on Re-Os isotopic dating for the molybdenite from this deposit is undertaken to determine metallogenic epoch and dynamics setting of the deposit. Re-Os isotopic dating for the molybdenite yields model ages ranging from 123.9 ± 1.9 Ma to 124.7 ± 1.8 Ma, with a weighted mean age of 123.4 ±0.81 Ma, and an isochron age of 127 ± 16 Ma, MSWD = 0.25, indicating that the metallization was at late Yanshanian. The content of Re in molybdenite is （330.1 ±4.0-367.9 ± 3.1 ） xl0^-6, which demonstrates mantle derived metallogenic sources. Integrating the region-al tectonic evolution and the metallogenic characteristics of other contemporaneous Cu-Mo deposits in the re-gion, it is suggested that the Cu-Mo mineralization of this deposit occurred in an active epieontinental environ-ment under lithospheric extension resulted from the subduction of the Izanagi plate to the Paleo-Asia continental margin at late Yanshanian. The Mantle wedge was partially melted with large amount of metallogenic elements dissolved in it. Under the favorable conditions of crust-mantle interaction, large-scale magmatic activity turns out to be the important mechanism of the mineralization of many Cu-Mo deposits in the Xiaoxingan Range-Zhangguangcai Mountain metallogenic belt, including the Xintian Cu-Mo polymetallic deposit.
