东川因民铜矿区昆阳群因民角砾岩特征及其与成矿关系的研究

【作者】 姚飞；

【导师】 黄浩；

【作者基本信息】 昆明理工大学 ， 矿产普查与勘探， 2010， 硕士

【摘要】 东川铜矿区位于“康滇地轴”云南段的北端,为裂谷型铜矿。在该矿区昆阳群因民组中,赋存着火山喷流-沉积作用形成的稀矿山式铁铜矿,在其下常赋存着一层因民角砾岩,通过对这层角砾岩的研究,解读出在火山喷流-沉积成矿时的古地形,而且对其进行分类对比分析其成因,对地层的划分起到辅助作用,还可以对寻找稀矿山式铁铜矿提供指导作用。因此矿区因民铜矿区中发现的稀矿山式铁铜矿及其下伏的因民一段角砾岩是本文研究的重点。1.通过对对项目发现的角砾岩的空间分布,模拟出当火山喷发时的古地形,推断出矿体赋存的形态。2.稀矿山式铁铜矿总体的分布形态和因民一段角砾岩的分布是一致的,紧紧的覆盖在因民一段角砾岩之上,角砾岩的形态决定着稀矿山式铁铜矿的分布形态。稀矿山式铁铜矿以及因民一段角砾岩的分布类似于一个穹窿的形态,稀矿山式铁铜矿紧紧的‘包裹着因民一段角砾岩。推断其东部具有巨大的找矿空间。3.通过对因民一段角砾岩进行系统的分类及其成因分析,将其分成火山作用形成的复杂成分角砾岩、沉积作用形成的角砾岩以及构造作用形成的角砾岩。以发现的液压致裂角砾岩进行研究为基础,探讨了争论已久的昆阳群地层划分,在火山喷发后,由于液体(气体)压力,使周围的岩石强度降低、脆性增加。在压力达到一定程度的时候,岩石就会破碎,形成角砾岩或者碎裂岩,因此认为因民组底部的角砾岩并不是由于大型的逆冲推覆构造形成的,因民组和其上的落雪组、黑山组、青龙山组(上四组)及其下的平顶山组、菜园弯组、望厂组、洒海沟组(下四组)为正常的地层叠层关系。4.由于因民一段角砾岩的存在,为稀矿山式铁铜矿的成矿热液提供了富集运移的通道,在富集成矿的阶段,成矿热液(Cu、Ag等)会随着角砾岩的隙缝上升。为成矿提供了必不可少的条件。更多还原

【Abstract】 Dongchuan copper deposit,which is a rift-type copper located in the "Kang-Dian axis" in the north of Yunnan section.In Kunyang Yinmin Group of Dongchuan Copper,hosts "Xikuangshan Type"iron-copper shaped by Volcanic-Sedimentary,beneath which often there is a layer of breccias；via the researching for the layer of breccia,we can interpret that the breccias was shaped by volcanic-sedimentary mineralization and we can also analyze the causes of breccias by the classification,which can play a supporting role in the formation of the stratigraphic division and also can provide an guidance for the seeking to "thin Mine Type" iron-copper.The"thin Mine Type"/The "rare mine-type" iron-copper found in Yinmin Copper mine of Dongchuan along with under the V section of breccia in Yinmin is a result of the focus of this paper.1.Via drawing the breccias spatial distribution of the project researched in which are found, it can simulate the paleotopography which was formed when ancient volcanic erupted and we can also infer the form of ore body.2.The iron patterns and the distribution of the thin copper mines is as same as the reccia in the section of Yinmin,on the top of which is covered tightly by the thin copper mines.The "rare mine-type" iron-copper distribution pattern is depended on the form of breccias.The distribution of the"rare mine-type" iron-copper breccias as well as the reccia in the section of Yinmin is the similar to a dome shape.The reccia in the section of Yinmin is wrapped by the "rare mine-type" iron-copper breccias.We can infer there will be a great exploration of space in the east of section of Yinmin.3.Through a systematic classification and an analysis of its causes of breccia in section of Yinmin,it can be divide into three types breccias which are the breccia formed by volcanism,deposition and tectonization.Based on researching the cause of Hydraulic Pressure Fracturing Breccia and after discussing the stratigraphic classification of Kunyang Group,which has been argued controversially for long time,we find that the breccia at the bottom of Yinmin Group is not was not due to a Large-scale Overthrust Structure；Yinmin Group together with its upper layers-Luoxue Fm,Heishan Fm and Qinglongshan Fm -and its underlayer-Pingdingshan Fm,Caiyuanwan Fm,Sahaigou Fm,Meidang Fm (called Four Underlayer Formations.)called Four Upper Layer Formations)is the nature stratum stromatolite relations.4.After the interval of the first volcanic eruption,because of a certrain degree of pressure from the fluid or gas to the underlying breccias,the rock strength around is weaken while brittleness will increase.When the pressure reaches a certain level,the rock will be broken into and form a breccias or rock fragments.Mineral fluid(Cu,Ag etc.)will also ascend along with the rock breaking gap,which offers the ore sources and channels for the formation of "rare mine-type"Iron-Copper mineralization and provides the essential conditions for mineralization.更多还原