Molybdenite Re-Os and muscovite Ar/ Ar dating of quartz vein-type W-Sn polymetallic deposits in Northern Guangdong, South China

摘要

Northern Guangdong is an important part of Nanling tungsten-tin metallogenic belt, South China. The tungsten mineralization in this area consists of mainly quartz-wolframite vein-type mineralization, with W-Sn polymetallic deposits mostly distributed at the outer contact zone between concealed Late Jurassic granitic stocks and Cambrian-Ordovician low-metamorphosed sandstones and shales. Molybdenite Re-Os and muscovite ~(40)Ar/~(39)Ar isotopic dating of three typical tungsten vein-type deposits (Yaoling, Meiziwo, and Jubankeng) in northern Guangdong, show that two episodes of Late Jurassic W-Sn polymetallic mineralization occurred in this area: an early episode during the Late Jurassic (158-159 Ma) represented by the Yaoling, Hongling, and Meiziwo tungsten deposits, and a younger event during the Early Cretaceous (138 Ma) represented by the Jubankeng deposit. Analysis of available radiometric ages of several W-Sn deposits in the Nanling region indicate that these deposits formed at several intervals during the Mesozoic at 90-100,134-140,144-162, and 210-235 Ma, and that large-scale W-Sn mineralization in this region occurred mainly between 150 and 160 Ma.