楚雄盆地六苴铜矿含矿岩系沉积演化、成矿时代及成矿深度分析

六苴铜矿是云南楚雄盆地重要的砂岩铜矿,矿体呈层状、似层状产出。晚白垩世,六苴铜矿区沉积环境从曲流河演化为氧化--咸化湖泊,形成了边滩、决口扇和水下扇等有利相带。成矿作用发生在成岩或埋藏阶段,在古新世元永井早期,马头山组下段(主含矿层)埋深至928m时,含矿热液向有利沉积相带运移,这个过程可能延长至元永井末期(56Ma),当时主含矿层埋深至3400m。进入始新世改造期,形成了一些细铜矿脉。

Analysis on sedimentary evolution, mineralization epoch and depth of ore-bearing rocks in Liuju copper deposit, Chuxiong Basin

Liuju copper deposit is an important sandstone-type copper deposit in Chuxiong Basin of Yunnna Province. The orebody occurs chiefly in stratiform and stratiform-like structures. The sedimentary environment evolved from mendering river to oxidation-salinization lake in Late Cretaceous,and formed some favorable facies as point bar,crevasse fan and sublacustrine fan. The mineralization took place in diagenetic or buried stages. In early Yuanyongjing stage of Paleocene,while the burial depth of lower Matoushan Formation （main ore-bearing strata） as 928 m,the ore-bearing hydrothermal migrated to favorable facies,and this process may extend to late Yuanyongjing stage （56 Ma）,while the burial depth of main ore-bearing strata as 3 400 m. The reformation period may begun in Eocene,and formed some thin copper veins.