云南大平掌铜多金属矿床成矿作用

云南大平掌矿床位于澜沧江火山岩带的中南段,左侧是澜沧江和酒房深大断裂。矿区内发育一套形成于岛弧环境的上石炭统细碧-石英角斑岩系,矿体产于流纹质火山岩中,产状与火山岩一致。矿体分2类,上部为块状矿体,下部为细脉-浸染状矿体。矿床内热液蚀变发育,特别是浸染状矿体中更强,并从矿体中心向外侧形成分带。具工业意义的Cu、Pb、Zn等元素以硫化物形式产出。S、Pb、Sr、Nd等同位素成分表明,成矿物质来源于地幔-下地壳。尽管矿体受后期构造破坏强烈,但综合研究表明,该矿床仍具有世界上绝大多数火山成因块状硫化物矿床的共同性。它与区内类似矿床的差异性,为在该区寻找火山成因块状硫化物矿床开辟了新方向。

Mineralization of Dapingzhang massive sulfide copper-polymetallic deposit in Yunnan

The Dapingzhang ore deposit in Yunnan Province is located in the central southern part of the Lancangjiang volcanic zone. On its left side are Lancangjiang and Jiufang large and deep faults. In the ore district, a suite of Upper Carboniferous spilite-keratophyre sequence formed in an island arc environment. Ore bodies whose attitude is similar to that of the volcanic sequence occur in rhyolitic volcanic rocks. These ore bodies may be divided into two types, i.e. massive ore in the upper part and veinlet-disseminated ore in the lower part. Hydrothermal alteration was widely developed in the ore district, especially in places of disseminated ores, forming an alteration zone from the center outwards. Elements such as Cu, Pb and Zn occur as economic sulfide minerals. A study of S, Pb,Sr, Nd isotopic composition has revealed that ore-forming materials of the ore deposit were derived from the mantle and the lower crust. Although the ore bodies were subjected to intense destruction from late tectonic activity, the ore deposit still has the general character of most volcanic massive sulfide deposits in the world. The difference between this ore deposit and other similar deposits contributes to searching for new volcanogenic massive sulfide ore deposits in this region.