一、引言滇西前寒武纪地层,主要分布于金沙江—红河一线以西。可以划分为哀牢山—石鼓变质带,澜沧江变质带及高黎贡山变质带,沿金沙江—哀牢山,澜沧江及怒江三个深断裂西侧呈狭长的带状分布。前人对上述变质岩带均作过不同程度的研究,对其划分与对比众说纷云,概括起来主要为元古代和古生代两种意见。笔者在研究大量前人资料,并结合区域地质成果综合分析的基础上,对各变质带中的前寒武系划分如表1,并分别论证于后。 I. Introduction Precambrian strata in western Yunnan are mainly distributed to the west of the Jinsha River - Red River. It can be divided into Ailaoshan-Shigu metamorphic belt, Lancangjiang metamorphic belt and Gaoligongshan metamorphic belt, which are distributed along the narrow belt on the west of the three deep faults such as Jinsha River, Ailao Mountain, Lancang River and Nu River. The predecessors made different degrees of study on these metamorphic rock belts, and their division and contrast were numerous and varied. They were generally summarized as Proterozoic and Paleozoic. On the basis of studying a great deal of forefathers’ data and combining with the comprehensive analysis of the regional geological results, the author classifies the Precambrian in each metamorphic belt as shown in Table 1, and respectively discusses them in the later.