四川颇豁罗拉打玄武岩型铜矿床地质特征及控矿因素分析

发布时间：2018-05-25 02:45

本文选题：铜矿床 + 地质特征　；参考：《成都理工大学》2017年硕士论文

【摘要】：颇豁罗拉打铜矿矿床位于四川省美姑县境内,其产出的大地构造位置为扬子陆块西南缘攀西裂谷带中,含矿建造为峨眉山玄武岩。峨眉山玄武岩被认为是地幔柱作用的产物,广泛发育于二叠系中,位于扬子克拉通西缘,主要分布于中国西南地区,东西宽大于900km,南北长大于1000km,其中蕴含着丰富的铜铁矿资源,特别是攀西裂谷地区,发现了大量中小型铜铁矿床,体现了良好的找矿潜力。本论文在大量野外实地调查及室内样品分析的基础上,结合大量前人对区域矿床(点)资料,在研究区域地质背景、矿区地层特征、矿体特征等基础上,对该矿床的控制因素进行了分析,并对该地区的找矿潜力进行了初步探讨。矿区位于攀西裂谷普雄河断裂带东侧,二叠系峨眉山玄武岩地层发育较好,矿化特征明显,矿体位于矿区北部,含矿地层为二叠系峨嵋山玄武岩组(P3e),主要为峨眉山玄武岩喷发构造控矿。由于地表覆土厚,矿体在地表出露情况不好,通过工程揭露,矿体形态为似层状、脉状,地表未出现分支复合。矿体厚一般0.14~2.91m,最厚2.91m,平均1.41m,厚度变化系数64.92%;品位一般0.17%~6.01%,平均1.14%。矿体主要赋存峨眉山玄武岩下段(P3e1),其下伏地层为中二叠统茅口组(P2m),二者为不整合接触。其含矿岩性为致密状、气孔(杏仁)状、斑状玄武岩,受玄武岩喷发构造控制;矿体围岩蚀变较明显,一般沿矿体边缘都有蚀变带,主要为碳酸盐化、黄铁矿化、绿泥石化、硅化等,其中与矿体富集关系最为密切的是孔雀石化、硅化;矿物成分复杂,金属矿物有黄铜矿、黄铁矿、斑铜矿、辉铜矿、铜蓝、蓝铜矿和孔雀石等;非金属矿物主要为绿泥石、石英、绢云母、长石、辉石等。有用矿物以次生硫化物为主,次为原生硫化物。初步分析认为,该矿床为玄武岩浆期后热液型矿床。玄武岩浆活动提供了成矿物质来源,并促使了后期成矿元素的富集成矿。古大陆大裂解时期,中基性岩体的侵入,为本区内生金属矿床的形成奠定了成矿物质基础,而岩浆热液活动也是成矿元素富集或沉淀原因,即玄武岩浆喷发晚期或间歇期火山热液和玄武岩浆冷凝分异的含矿热液以及熔岩的热力作用直接或参与成矿。该区复杂的断裂结构为铜矿的形成创造了有利条件,而原生构造如气孔、杏仁、斑状则有着裂隙较多,孔隙度较高利于流体的交代成矿或者贯入,为成矿流体提供了良好的聚集空间和运移通道。通过大量地质分析,结合物探手段,初步探讨了该区的找矿潜力,并总结了找矿模型。研究表明,在矿区南部铜矿化带物探特征明显,在野外露头观察中层状的铜矿体规模相对较大,且铜矿品位及质量也较好,具有较好的找矿前景。直接找矿标志为氧化露头中孔雀石化。
[Abstract]:The Pohuolata copper deposit is located in Meigu County, Sichuan Province. The tectonic location of the deposit is in the Panxi rift belt of the southwest margin of the Yangtze block, and the ore-bearing formation is Emeishan basalt. Emeishan basalt is considered to be the product of mantle plume, widely developed in Permian, located in the western margin of Yangtze craton, mainly distributed in southwest China, with a width of more than 900km in the east and west, and a length of more than 1000km in the north and south, which contains abundant copper and iron ore resources. Especially in Panxi rift area, a large number of small and medium copper and iron ore deposits have been discovered, which shows good prospecting potential. On the basis of a large number of field investigations and indoor sample analysis, combined with a large number of previous data of regional deposits (points), this paper studies the regional geological background, mining area stratigraphic characteristics, orebody characteristics and so on. The controlling factors of the deposit are analyzed and the prospecting potential in this area is preliminarily discussed. The ore area is located on the east side of the Puxiong River fault zone of Panxi rift, the Permian Emeishan basalt strata are well developed, and the mineralization characteristics are obvious. The orebody is located in the northern part of the mining area. The ore-bearing strata are Permian Emei Mountain basalt formation (P _ 3e _ 3), which are mainly controlled by Emeishan basalt eruption structure. Because of the thick overlying earth, the orebody is not well exposed on the surface. Through engineering, it is revealed that the orebody is layered, veined, and there is no branch and compound on the surface. The thickness of ore body is generally 0.14 ~ 2.91 m, the thickest is 2.91 m, the average is 1.41 m, the coefficient of thickness variation is 64.92, and the grade is 0.17 ~ 6.01, with an average of 1.14. The orebody is mainly located in the lower member of Emeishan basalt, P3e1, the underlying strata of which is the middle Permian Maokou formation (P2mGU), and they are unconformable contact. The ore-bearing rocks are densified, stomatal (almond) like, porphyry basalt, controlled by basalt eruption structure, and the alteration of the surrounding rock of the orebody is obvious, and there are alteration zones along the edge of the orebody, mainly carbonate, pyrite, greenstone, etc. The silicification is most closely related to the enrichment of orebodies, such as peacock fossilization, silicification, complex mineral composition, chalcopyrite, pyrite, chalcopyrite, copper blue, blue copper and malachite, etc. Non-metallic minerals are mainly chlorite, quartz, sericite, feldspar, pyroxene and so on. The useful minerals are mainly secondary sulfides and secondary primary sulphides. Preliminary analysis shows that the deposit is a Black Tortoise magmatic posthydrothermal deposit. Black Tortoise magmatism provides the source of ore-forming material and promotes the enrichment of ore-forming elements. During the great pyrolysis of the Paleocontinent, the intrusion of the basic rock bodies in the middle of China laid the basis for the formation of the metallogenic metal deposits in this area, and the magmatic hydrothermal activity was also the reason for the enrichment or precipitation of the ore-forming elements. That is, the mineralized hydrothermal fluid of Black Tortoise magma eruption late or intermittent period and Black Tortoise magma condensate differentiation, and the thermal process of lava directly or participate in ore-forming. The complex fault structure in this area creates favorable conditions for the formation of copper deposits, while primary structures such as pores, almonds and porphyry have more cracks, and higher porosity is conducive to metasomatic mineralization or penetration of fluids. It provides a good accumulation space and migration channel for the ore-forming fluid. Based on a large number of geological analysis and geophysical means, the prospecting potential of this area is preliminarily discussed, and the prospecting model is summarized. The results show that the geophysical prospecting features of the copper mineralization zone in the south of the mining area are obvious, the scale of the layered copper ore body in the field outcrop observation is relatively large, and the grade and quality of the copper deposit are better, so it has a better prospecting prospect. The direct prospecting mark is peafowl petrifaction in oxidized outcrop.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.41

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