康滇地轴北缘新台子金矿区矿床地质特征及找矿方向浅析

Geological Features and Prospecting Direction of the Xintaizi Gold Ore Field in the Northern Margin of the Xikang-Yunnan Axis

新台子金矿区在成矿区带上属于海西期构造剪切带金成矿带,该带受丹巴弧形构造、大渡河韧性剪切构造及海西期基性-超基性岩浆活动的共同影响,以分布丰富的矿产资源为特征,是扬子地块西缘重要的贵金属成矿带。文章综合分析了区内矿床地质、控矿构造、矿石矿物、蚀变组合等成矿地质条件,将区内矿床成因类型确定为浅层低温热液石英脉型和构造破碎带蚀变岩型。两种矿床类型均受到地层、构造、岩浆岩的控制,具备形成小-中型规模金矿床的有利条件:①新台子金矿区及其邻区贵金属成矿带的成矿物源主要是前震旦系康定群;②深大断裂是多源成矿物质迁移的主要通道,壳源岩浆活动为成矿物质活化提供了热源;③泥盆系危关群炭质绢云板岩、千枚岩等黑色岩系作为有机化学障,使自下而上的含矿流体内的金元素沉淀、聚集成矿。

The Xintaizi gold ore field belongs to a gold metallogenic belt of the Hercynian shear zone, which is affected by the Danba arc structure, ductile shear structure of the Daduhe River and Hercynian basic-uhrabasic magma activity. This gold metallogenic belt is characterized by abundant miner- al resources, and is a precious metallic metallogenic belt in the western margin of the Yangzi block. This paper analyzes the geological conditions for min- eral deposits, ore-controlling structure, ores and minerals and alteration association and suggests that the ore deposits are of the hydrothermal vein type with low temperature and shallow layers and of the altered rock type in fractured alteration zones, which are controlled by strata, structures and magmatic rocks. This deposit shows a good potential of forming small and medium-sized gold deposits. （ 1 ） The ore-forming materials of this precious metallic metal- logenic belt in the Xintaizi gold field and its neighboring gold field are of the Sinian Kangding Group. （2） Deep faults serve as the main migration conduits for multi-source ore-forming materials, and crustal source magma provides heat for the activation of ore-forming materials. （ 3 ） The Carbonaceous fine- grained clastic rock of the Devonian Weiguan Group and black rock series like the phyllite are organic chemical barriers, making it possible to precipitate gold element inside the metallogenetic fluid from bottom to top and to realize mineralization.