摘要
在云南东川滥泥坪铜矿白锡腊铁铜矿段深部找矿预测中,开展了矿山深部工程岩相学填图技术研发与试验,实践证明该新方法在矿山深部隐伏矿找矿预测中具有较强的隐伏矿(新类型铁铜矿和新矿种)找矿预测能力。在构造-岩相学三级单元上,新发现的铁(钛)氧化物铜金型(IOCG)矿床与斜切地层产出的碱性杂岩墙(枝)密切有关。侵入岩岩相学填图表明,分异较好且具有明显岩相学分带的碱性杂岩墙(枝)成矿潜力大,铁(钛)氧化物铜金型(IOCG)矿与碱性铁质辉长岩-闪长岩等岩相学分带及侵入构造关系十分密切;分异较差且缺乏岩相学分带的岩墙成矿潜力低;因此,碱性铁质杂岩墙(枝)岩相学分带完整及侵入构造等是今后找矿勘查的主要标志和对象。对铁氧化物铜金型(IOCG)矿体而言,构造-岩相学的亚相填图证明储矿构造及富含铜磁铁矿矿体一般位于碱性铁质杂岩墙(枝)底部和上部。含铜磁铁富矿体主要由角砾状和块状铁铜矿石组成,这种矿体定位于隐爆角砾岩筒(带)中;构造-流体岩相学填图发现,围绕碱性杂岩墙(枝)分布的糜棱岩化相带和碎裂岩化相带也是主要储矿构造岩相带,赋存铁铜矿脉;脉带型铜银矿赋存在蚀变碳酸盐岩层中发育的裂隙破碎带之中,主要为含铜硅化铁白云石化蚀变带和镜铁矿硅化铁白云石方解石脉。钛矿(新矿种)主要赋存在蚀变闪长岩和蚀变辉长岩两个亚相中,在剖面和平面上,钛矿(化)体位于铁氧化物铜金型(IOCG)矿体两侧,主要由钛磁铁矿-钛铁矿微相和金红石-钛铁矿微相构成,钛赤铁矿和钛磁铁矿微相属于钛矿化蚀变系统。
Applications of lithofacies mapping had been promoted at the deep part of Dongchuan copper mine in order to probe the key technological puzzle of whether the Xikuangshan-type copper bearing magnetite orebody or a new type( iron-oxide copper gold, IOCG) at the deeper part of Baixila ore district. Results of lithofacies mapping have been proved to be of high abilities in discovery and prospecting predicting for the buried orebodies at the deeper part of the operation mine. In the scale of tectonic lithofacies of this orefield, IOCG found recently are closely related to alkaline complexes dikes or branches with cut across the strata, and their intrusive tectonics. On one hand, lithofa- cies mapping of the intrusive bodies indicate that alkaline complexes with good differentiation in different zonation of lithofacies are of higher potentials in mineralizations whereas metallogenic tectonics are attached to sub-lithofacies of alkaline gabbro and diorite, and their intrusive tectonics. On the other hand, alkaline complexes' poor differentiation is of lower potential in mineralizations. Therefore, tectonic lithofacies indexes of prospecting and prediction are main objects including alkaline complexes with good differentiation, completely zonation of lithofacies and their intrusive tectonics in mineral exploration and predications in the future. For IOCG only, IOCG orebodies are located in top, upper and base parts of alkaline complexes dikes or branches because the metallogenic and ore-hosting tectonics were indicated by the mapping of sub-lithofacies and micro-lithofacies. However, IOCG orebodies with breccia-type and massive Fe-Cu ores at higher-grades for Fe, Cu, Ag and Au, and are located in the cryptoexplosive breccia-type bodies in the barrel-shape. Mylonite and cataclasite zones outlined by mapping of tectonic fluid lithofaeies encom- passed alkaline complexes dikes or branches. These zones in hosting vein-zone type Fe-Cu veins also are one of the main ore-hosting tectonics. On the contrary, copper-silver orebodies in vein-zone-shaped, consisting copper-bearing silicified ferrodolomite altered rock and specularite-silicified ferrodolomite calcite veins, are located in fractured zone in the altered carbonate rocks. The most important is a new mineral commodity (titanium deposit) outlined in two sub-lithofacies of altered gabbro-diorite during logging and mapping of lithofacies. In the section and horizontal plane, orebodies of titanium mineralization are located around both sides of the IOCG orebody, and titanium minerali- zation are composed of titanomagnetite-ilmenite micro-lithofaeies and rutile-ilmenite micro-lithofacies. In the fact, tit- anomagnetite micro-lithofacies and Ti-hematite micro-lithofacies are attached to titanium-bearing mineralized altered system. In the summary, it can be predicated, that a middle-scale IOCG and Ti deposits with promising prospecting potential would be found in the on-going exploration at the deeper part of Baixila ore district in the Lanniping copper mine, covering 2. 9 km^2 at the surface with the depth of 2000 m vertically.
出处
《矿物学报》
CAS
CSCD
北大核心
2012年第1期101-114,共14页
Acta Mineralogica Sinica
基金
科技部转制科研院所专项资金项目(批准号:2011EG115022)
国家科技部科技支撑项目(批准号:2006BAB01B09)
中色地科矿产勘查股份有限公司和昆明中色地科研发项目