摘要
矿床形成于兰坪-云龙古新世湖盆东部,沘江同生断层西侧的次级坳陷。容矿岩系为古新统云龙组中、上段。中段为重力滑塌岩块及角砾岩相-构造活动型冲积扇相沉积;上段为河口砂坝相沉积。矿床两层结构明显:上部是化学沉积成矿系统;下部是补给成矿系统。两系统的矿体形态、矿石类型、结构构造、矿化及蚀变强弱均有显著差异。矿床显示SEDEX型(Sedimentary Exhalation喷气沉积的缩写)矿床特征。成矿物质系深源,硫来自硫酸盐经分解而产生的还原硫,成矿介质属混合水。矿床在有利的聚矿次级坳陷、导矿同生断层、有利矿化沉积岩相、上下屏蔽层圈闭及外来岩系掩埋等条件下耦合形成。属陆相SEDEX型铅锌矿床。
This ore deposit is formed in the subordinate depression west of the Bijiang cogenetic fault in the east part of Palaeocene Lanping- Yunlong lake basin. The middle, upper members of Palaeocene Yunlong Formation are the ore bearing rock series. The middle member is the gravity slide collapse block and breccia facies -structural movement type alluvial fan facies sediments. The upper member is the sediment of river mouth bar facies. The ore deposit has an evident 2 - layer structure ： the chemical sediment metallogenetic system in the upper one; the supplementation metallogenetic system in the lower. Their orebody form, ore type, texture and structure, intensity of metallogenesis and alteration are very different each other. The ore deposit is characterized by the SEDEX （Sedimentary Exhalation） type ore deposit. The metallogenetic material has a deep -seated source. The S originates from the reduced S of sulfate decomposition. And the metallogenesis medium belongs to the mixed water. The ore deposit is formed under the comprehensive conditions of subordinate depression advantageous to ore accumulation, cogenetic fault of ore transmission, sedimentary rock facies beneficial to metallogenesis, closure of overlying and underlying barrier beds and burying of allochthonous rock series. It belongs to the land facies Pb -Zn deposit of SEDEX type.
出处
《云南地质》
2007年第1期1-14,共14页
Yunnan Geology
