西南“三江”地区地处冈瓦纳大陆与欧亚大陆结合带,是古特提斯构造域的东延部分。伴随古特提斯洋的闭合,区域内自西向东形成了澜沧江缝合带、昌宁-孟连缝合带、金沙江缝合带及甘孜-理塘缝合带,其中昌宁-孟连缝合带被认为是古特提斯洋主洋盆闭合后的残余。作为古特提斯洋的重要分支,金沙江洋的形成与演化长期受 The southwestern “Sanjiang ” area is located in the belt of the Gondwanaland and Eurasian continent, and is the eastern extension of the ancient Tethys tectonic domain. Along with the closure of the ancient Tethys Ocean, the Lancang suture zone, Changning-Menglian suture zone, Jinshajiang suture zone and Garze-Litang suture zone are formed from west to east in the area, of which the Changning-Menglian suture zone is considered Is the remnants of the closure of the ancient Tritis oceanic basin. As an important branch of the ancient Tethys Ocean, the formation and evolution of the Jinsha River have long been affected