西南三江地区造山演化过程及成矿时空分布

Orogenic Evolution and Metallogenic Time-Space Distribution in Jinshajiang-Lancangjiang-Nujiang Region,Southwest China

三江地区单凭“一次造山”是难以圆满解释的 ,在此试以“多次造山”和“多期成矿”的思路作出合理的说明。晚古生代 中生代早期为多岛海造山阶段 ,羌塘弧、江达弧和临沧弧应为前锋弧 ,其后由一系列弧后盆地和岛弧或残余弧 (微大陆 )组成。中生代中—晚期为陆内俯冲造山阶段 ,推测金沙江带、哀牢山带和龙门山 锦屏山带为俯冲主边界 ,从而形成该区燕山期重熔型花岗岩带 ,并控制相应矿产的分布特征。新生代陆内转换造山阶段造成具特征的构造 岩浆 成矿带 。

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.