On the formation and evolution of the Zhoutan group of central Jiangxi province

Zhoutan group of central Jiangxi province is located in the conjuncture area of Yangtze and Cathaysia blocks and Jiangnan orogen. It has been previously considered to be Precambrian metamorphic basement of Cathaysia block or to be a component part of Caledonian fold zone. On basis of integrated petrological, geochronological and geochemical data, a new modal of formation and evolution has been proposed. The results suggest that meta-basalts and meta-sedimentary rocks of Zhoutan group were formed in the Mesoproterozoic and 830-820 Ma, respectively, and they together experienced Paleozoic metamorphism. In this regard, the Zhoutan group should be redefined as Zhoutan Complex. The modal of oceanic subduction in the Neoproterozoic and intracontinental orogen in the Paleozoic in the best one to interpret the formation and evolution of the Zhoutan Group. (authors)