缅北中部脉金矿带控矿因素及成矿作用浅析

A PRELIMINARY ANALYSIS OF ORE- CONTROLLING FACTOR AND METALLOGENESIS OF GOLD LODE ZONE IN THE CENTRAL PART OF NORTH BURMA

缅北中部 ,印缅岛弧及弧后盆地东侧、新生代造山带的前缘推覆构造带中 ,分布有许多脉金矿床及矿点 ,构成金矿带。矿带、矿田、矿床及矿体的形成、分布及其规模 ,受不同级别的近南北向逆冲断裂 ,及其间派生的北东向张性扩容断裂组成的剪切断裂带控制。可渗透的下麦尔组下部中—粗粒砂岩 ,起着很好的容矿作用。下麦尔组上部泥岩、细砂岩、粉砂岩和页岩互层单元 ,在携金热液的迁移、氧化硅的沉淀和矿质沉积定位等方面 ,可能起到圈闭作用。

In the central part of north Burma, there are many gold lode deposits and occurences in the front nappe of Cenozoic orogenic belt east of the India burma island arc and the retroarc basin, which form a huge gold lode zone. The formation, distribution and scale of gold lode zone, ore field, deposits and ore bodies are controlled by the shear fracture zone consisting of nearly N S thrust and NE tension fault. The permeable medium coarse grain sandstones of the lower part of Lower Male Formation act as a good host of the ore. And the mudstone, fine sandstone, siltstone and shale of the upper part of Lower Male Formation possibly play an important part in the migration of Au bearing hydrothermal solution, precipitation of silica, deposition and locating of metallogenetic material.