Muscovite 40Ar-39Ar and LA-ICP-MS cassiterite U-Pb dating of Yangjiashan quartz scheelite deposit, Xiangzhong ore district and its geological significance

Yangjiashan scheelite deposit is a quartz vein type one hosted in Late Devonian biotite monzogranite that intruded in the surrounding Neoproterozoic slate in the Xiangzhong low -temperature Sb-Au-W ore district, South China. It is one of the few granite related quartz vein scheelite deposits in the world, and its ore-forming mechanism is still unclear. This paper reported the U-Pb isotope dating of cassiterite by the method of in-situ LA-ICP-MS from Yangjigshan tungsten deposit. Cassiterite coexisting with scheelite yields a weighted mean Pb-206/U-238 age of 410.4 +/- 5.7Ma (MSWD = 1.5, n = 24). Muscovite associated with scheelite yielded a 40Ar-39Ar plateau age of 395.4 +/- 3.2Ma, with an isochron age of 398.2 +/- 4.4Ma. We infer that Yangjiashan tungsten deposit was formed in the Late Devonian, which is consistent with the zircon U-Pb ages of the biotite monzogranite within analytical uncertainties. Combined with previous ages in the literature, it is suggested that a Late Devonian W-Au metallogenic event developed in the Xiangzhong ore district. The above research results not only deepen the understanding of metallogenic theory of tungsten gold deposits in Xiangzhong ore district, but also provide important theoretical support for the breakthrough of prospecting and exploration.