Geological characteristics and metallogenic age of Tengshan'ao Sn deposit in Dayishan of South Hunan and its prospecting significance

Abstract

The Tengshan'ao Sn deposit, located at the Dayishan ore field, Nanling Range, is one of the recently explored deposits in this region. In this study, LA-MC-ICP-MS cassiterite U–Pb and muscovite 40Ar-39Ar isotopic dating analyses for altered granite-type Sn ores yielded ages of 156.7 ± 4.3 Ma and 151.1 ± 1.5 Ma, respectively. These ages are consistent to the LA-MC-ICP-MS zircon U–Pb age of the fine-grained two-mica monzogranite (158.2 ± 1.6 Ma), indicating a coeval magmatism and mineralization for the Late Jurassic Tengshan'ao Sn deposit. It is further demonstrated that the formation of this deposit is related to the Early Yanshanian (160-150 Ma) large-scale diagenesis and mineralization in Nanling Range. It is suggested that the late-stage fine-grained two-mica (muscovite) granite has an indicative significance for searching the altered granite type Sn polymetallic mineralization.