丹池成矿带五圩矿集区矿床地质特征及构造成矿分析——以箭猪坡矿床为例

Geological Characteristics and Metallogenic Analysis of the Deposit in the Wuxu Ore-Concentrated Area of the Nandan-Hechi Metallogenic Belt:A Case Study in Jianzhupo Deposit

根据岩层能干性特征,五圩矿集区整体结构为两"强"夹一"弱"的"三明治"岩层结构,以箭猪坡最为典型,赋矿层位为弱能干性泥岩层。通过对箭猪坡矿床脉状矿体构式和平面、剖面矿脉展布特征的观察和分析,判断矿体形成于印支早期脆—韧性逆冲剪切带中,矿脉呈雁列状向深部倾伏,之后受印支晚期断展褶皱和燕山期SN向褶皱叠加、改造,最终使矿脉走向为NNW、剖面呈正"八"字形分布。矿脉直接受脆—韧性逆冲剪切带分布范围的控制。由此推断,具备"三明治"岩层结构的丹池成矿带内,在中间的泥岩层内均可能赋存脆—韧性剪切带控制的脉状矿体。

The structure of rock formation in Wuxu ore-concentrated area likes ＂sandwich＂ without the exposed magmatic rocks,ore body is located in the middle of ＂sandwich＂ which is mudstone layer.Characteristics of construction of vein and the distribution of veins flat surface and section in Jianzhupo deposit of Wuxu ore field is analyzed and the results show that the ore body is formed in brittle-ductile thrust shear zone in the early phase of Indo-Chinese epoch.Ore body sank in the shape of echelon deeply, then it was reformed by the Wuxu fault propagation fold in the late phase of Indo-Chinese epoch afterwards and SN fold in the phase of Yanshanian, at last its strike is NNW and distribution looks like positively ＂eight＂ Chinese characters in the section.The late reformation makes ore body attitude of west wing and the core department of anticline uprightly, and ore body of west wing sinking from SW to NE deeply.It＇ s controlled directly by the distribution of right/left echelon vein in the early indosinian brittle-ductile thrust shear zone.It concludes that the rock strata have a ＂sandwich＂ in the Nandan-Hechi metallogenic belt, are likely to occur brittle-ductile shear belt which control vein orebody.