澜沧群是滇西南有名的含矿变质岩系,主要由灰绿、黄绿等色绢云母片岩、绢云英片岩、白云英片岩、夹炭质硅质板岩及变质中—基性凝灰岩组成,富含菱铁矿、赤铁矿和磁铁矿。呈南北向带状分布,范围大致北起昌宁、凤庆,经双江、澜沧到勐海打洛一带,而进入缅甸。分布面积达4,500平方公里。 Lancang Group is a well-known ore-bearing metamorphic rock series in southwestern Yunnan, and is mainly composed of sericite schist, sericite schist, dolomitic schist, carbonaceous siliceous slate and metamorphic-base tuff Composition, rich in siderite, hematite and magnetite. Was strip distribution from north to south, the scope of roughly Changning north, Fengqing, by the Shuangjiang, Lancang to Menghai Daluo area, and into Burma. Distribution area of ​​4,500 square kilometers.