兰坪金顶蜂子山铅锌矿床的构造控矿:来自三维空间数据分析的证据

Structural Controlling Mineralization of the Fengzishan Zn-Pb Deposit at the Giant Jinding Ore Field in Western Yunnan Province,SW China:Insights from 3D Spatial Data Analysis

滇西金顶超大型铅锌矿床的热液成矿和构造控矿特点突出,对其主要容矿岩石和断层耦合控矿机制仍不清楚。利用三维空间数据分析方法,对代表性的蜂子山铅锌矿床开展了矿化结构及其空间展布特征的综合研究。结果表明:Pb和Zn矿化中心呈现出东西向分带及差异性分段富集的特点,空间上并与黄铁矿、天青石(—重晶石)和石膏矿体共置;成矿流体的运聚受近SN向逆冲断层和近EW向走滑断层的共同控制,为其提供通道和沉淀空间;而金顶群(N_(1)j)的湖相氧化性含矿卤水在两组方向断层的联合驱动下,在三合洞组上段(T_(3)s^(3))地层中与其赋存的还原性流体幕式混合成矿,是该矿床发育的重要机制。尤其是,近SN向逆冲断层和近EW向走滑断层联合控矿特征的发现,为深入理解金顶超大型铅锌矿床成矿作用及指导找矿勘查提供了新的依据。

There occur huge amounts of lead,zinc and other metals hosted by a mixed clastic-carbonate sequence in the giant Jinding Zn-Pb Ore Field in western Yunnan Province,SW China.The discovered lead-zin core mineralization isobviously characterized by an epigenetic hydrothermal origin and the complexity of theore-hosted rocksand faults-controlling style.So far,the coupling mechanism amongst them is unclear.In thiscontribution,3D spatial data analysis on the Fengzishan Zn-Pb deposit were used to constrain the ore mineralization architecture and its spatial distribution characteristics,and to infer the coupling controlling mechanism between the main hosting rocks and the ore-controlling structures.The results reveal that the approximate NS-trending thrust faults and EW-trending strike-slip faults exerted a first-order control on the migration and accumulation of the ore-forming fluids,and provided for prior pathways and precipitation space.The distribution of the lead and zinc mineralization centers for the main ore bodies are parallel with the probable EW-trending faults,and of typical with the heterogeneous and segmented enrichment.They are spatially associated and/or intergrowth with pyrite,celestite(-barite)and gypsum as well.Therefore,the ore-forming fluids from the Miocene Jinding Group(N_(1)j)with a basinal brine in nature,have been driven and controlled bythe approximate NS-trending thrust faults and EW-trending strike-slip faults,and precipitated in the Upper of Sanhedong Formation(T_(3)s^(3))by episodic mixing of multiple fluids.In particular,the discovery of this couple controlling on the ore mineralization by the approximate NS-trending thrust faults and EW-trending strike-slip faults and ore-hosted rocks,can provide us for understanding deeply the ore-forming mechanism and some key guidance for the future prospecting and exploration of this ore deposits,including similar deposits.