滇东南地区是扬子、华夏、印支地块的汇聚部位。本区的八布蛇绿岩被认为是古特提斯洋分支右江洋盆的残留洋壳。对八布蛇绿岩进行的地质填图、岩石组合、地球化学和年代学综合研究表明,八布蛇绿岩具有较完整的组合,包括地幔橄榄岩、堆晶辉长岩、辉绿岩墙群、枕状玄武岩和放射虫硅质岩,但其是外来系统推覆在原地系统三叠系兰木组浊流沉积之上。其中地幔橄榄岩以方辉橄榄岩为主,熔岩和辉绿岩为低钾拉斑系列。稀土元素和微量元素具有类似N-MORB的特征,Ti/V比值为20~50之间,Nb/Yb-Th/Yb比值落在亏损地幔源区,应为MOR型蛇绿岩。斜长角闪岩SHRIMP锆石U-Pb年龄为272±8Ma(n=11,MSWD=0.54),表明其时代为早二叠世晚期。综合扬子西南缘晚古生代火山岩分布和沉积演化特征,我们认为八布蛇绿岩代表了二叠纪早期右江洋盆剧烈扩张期的残留洋壳。 Southeast Yunnan is the gathering place of Yangtze, Huaxia and Indochina plots. The Babu ophiolite in this area is considered to be the remnant oceanic crust of the Youjiang ocean basin that belongs to the Palaeo-Tethys Ocean. Geological mapping, rock assemblage, geochemistry and geochronology studies on the Bupu ophiolite show that the Bupu ophiolite has relatively complete assemblage including mantle peridotite, pluton-gabbro, diabase wall Pillow-like basalt and radiolammonium chert, but this is an alien system overlying turbidite deposition of the Triassic Lanmu Formation in situ. Among them, the mantle peridotite is mainly hterochromaite, while the lava and diabase are the series of low potassium pullulans. The REE and trace elements have similar N-MORB characteristics. The Ti / V ratio is between 20 and 50, and the Nb / Yb-Th / Yb ratio falls in the depleted mantle source zone and should be MOR-type ophiolite. The SHRIMP zircon U-Pb age of amphibolum is 272 ± 8Ma (n = 11, MSWD = 0.54), indicating that the age of the zircon was the early Early Permian. Based on the Late Paleozoic volcanic rock distribution and sedimentary evolution characteristics in the southwestern margin of the Yangtze, we think that the Bupu ophiolite represented the remnant oceanic crust during the intense Permian expansion of the Early Permian Youjiang basin.