Orogenic Evolution and Metallogenic Time-Space Distribution in Jinshajiang-Lancangjiang-Nujiang Region,Southwest China
LUO Yaonan YU Rulong (Sichuan Bureau of Geological Exploration for Mineral Resources, Chengdu, Sichuan,610081)
Geology of Jinshajiang Lancangjiang Nujiang region in Southwest China cannot be satisfactorily interpreted by the hypothesis"one orogenesis". An interpretation of "polyphase orogenesis" and "polyphase metallogenesis" has been proposed in the paper. Du ring the Late Palaeozoic Early Mesozoic archipelago orogenic stage, Qiangtang, Jomda and Lincang arcs should have served as the frontal arc, behind which a series of back arc basins and island arcs or remnant arcs (or microcontinents) was distributed. In the Middle Late Mesozoic orogenic stage of intracontinental subduction, Jinshajiang, Ailaoshan and Longmenshan Jinpingshan belts might have acted as the main intracontinental subduction zone, which caused the formation of Yanshanian remelting granites and controlled the distribution of mineral resources. In the Cenozoic stage of intracontinental transform orogenesis, the characteristic tectonic magmatic metallogenic zone was developed, which has a potential for the formation of large or superlarge deposits.