三江北西段楚多曲矿床近东西向控矿断裂构造的识别及找矿意义

The recognition of nearly east-west ore-controlling fault structure of Chuduochu deposit in the northwestern segment of Sanjiang and prospecting significance

三江北西段是西南三江成矿带的北段西延部分,已发现的矿床(点)明显受近东西向区域性断裂构造带及沿构造带分布的中酸性侵入岩体控制,成矿环境为典型的岩浆-构造活动环境。本文通过对楚多曲矿床在矿体特征、矿石特征、土壤地球化学特征对比基础上,新识别并确认了研究区近东西向断裂的控矿事实,改变了勘查工作只针对近南北向控矿断裂的现状;另外新发现了沿近南北向断裂与近东西向断裂复合部位侵入的二长斑岩体,针对其斑岩型矿化蚀变特征,初步探讨了斑岩型成矿可能;指出了研究区及区域下一步找矿方向。

The northwestern segment of Sanjiang is west extension part of the Sanjiang metallogenic belt’s northern segment in southwestern China,where the deposits (ore occurrence)that have been found are obviously controlled by nearly east-west regional faulted structural belt and intermediate-acid intrusive rocks distributing along the structural belt.The metallogenic environment is typically magma-tectonic activity environment.On the basis of comparing ore body characteristics,ore characteristics and soils geochemical characteristics of Chuduochu deposit,this paper has a new recognition and has confirmed the ore-controlling fact of nearly east-west fault in the research area,which changes the current situation that the exploration work only aims at nearly south-north ore-controlling fault.In addition,the intrusive monzonitic porphyry on the compound position along nearly south-north fault and nearly east-west fault has been newly found.In the light of porphyry-type mineralized and altered characteristics,this paper has discussed preliminarily the porphyry-type ore-forming possibility and pointed out the next step prospecting direction in the research area and region.