SHRIMP zircon U-Pb age of Tashan granitic pluton from Hu'nan Province and its geological significance

Tashan granite pluton covering an area of 200km² is an EW-trending batholith which is located at the eastern end of the Yangmingshan-Tashan tectomagmatic belt in southern Hunan. The pluton intruded into the Paleozoic strata and its interface is inclined to the wall rock, with the dip angle ranges from 30° to 50°. The pluton is composed four periods of pulsation intrusive rock bodies and its main lithology is biotite adamellite. The SHRIMP zircon U-Pb age of the second-stage pluton is 218±3Ma and the third is 215±3Ma, as measured by the Beijing SHRIMP Center of Chinese Academy of Geological Sciences. It is suggested that the Tashan pluton was formed in the Late Triassic period, and the age gap with the neighboring intrusive bodies is 3~5Ma, suggesting that the EW-trending Yangmingshan-Tashan tectomagmatic belt was probably formed in Indo-Chinese epoch. This area is rich in tungsten, tin, copper, lead and zinc polymetallic deposits and has bright future for ore prospect in that the mineralization in the Nanling region occurred not only in Yanshanian epoch but also in Indo-Chinese epoch.