安庆铜矿及周边地区构造解析及其对深部找矿的启示

发布时间：2018-04-21 08:03

本文选题：安庆铜矿 + 乌珠尖探区　；参考：《南京大学》2015年硕士论文

【摘要】：安庆铜矿位于安徽省安庆市怀宁县月山镇,是长江中下游铁铜成矿带重要铜矿床之一。经过多年的开采,浅部资源储量不断减少,深部找矿成为地质工作的主要任务。前人研究表明:月山地区矿体一般赋存于褶皱倾伏端及两翼部位,月山闪长岩体与月山组大理岩的接触带是成矿的必要条件。断裂构造控制矿床的空间分布和保存条件,NE和近EW向的两组基底断裂是良好的岩浆通道,NW和近SN向的两组断裂对矿体有破坏作用。因此,研究区构造精细分析对寻找深部矿体至关重要。本文通过对研究区褶皱构造的研究,认为百子山背斜轴向为NNE,该背斜的倾伏端——月山-黄土山背斜是有利的成矿部位。F1断层为成矿后断裂构造,对矿体起破坏作用,F1断层具有多期活动特征,以左行平移为主,其水平位移量为200～400m,推测乌珠尖勘探区的有利靶区可能向北平移。可控源音频大地电磁法(简称CSAMT)是依据矿石与围岩在电性上存在明显的差异性,在CSAMT反演剖面上寻找矿体引起的低阻异常带。但是,低阻异常本身具有多解性,如断层带和含水层等也可以引起低阻异常,仅仅利用CSAMT法指导找矿存在不确定性。本文通过对邻区已找到矿体对应CSAMT剖面曲线特征的研究,认为CSAMT曲线形态为"V"形低阻带和陡降低阻带可能成为有利的勘探部位;搜集乌珠尖勘探区及邻区19个钻孔资料和地表实测数据,制作了乌珠尖勘探区月山岩体顶面等深线图和月山组顶面等深线图,并将其投影至CSAMT曲线剖面上,得出CSAMT图地质剖面解释;在闪长岩与月山组碳酸盐岩接触带上寻找与邻区相似的含矿CSAMT曲线形态特征,提出有利的勘探孔位。野外地质调查研究确定了月山-黄土山背斜褶皱形态,朱冲矿区位于其北西翼,乌珠尖探区位于其南东翼,通过构造解析和含矿构造有利部位分析得知,在乌珠尖探区可能存在与朱冲矿体构造部位具有对称性的矿体。同时,根据CSAMT剖面设计的钻孔正好落在该背斜核部和南东翼有利成矿部位。本文利用物探资料与构造地质解析有效结合起来,两者相互补充,提高了寻找成矿靶区的可靠性。
[Abstract]:Anqing Copper Mine, located in Yueshan Town, Huining County, Anqing City, Anhui Province, is one of the important copper deposits in the iron-copper metallogenic belt in the middle and lower reaches of the Yangtze River. After many years of mining, shallow resources reserves are decreasing, and deep prospecting has become the main task of geological work. Previous studies have shown that the orebodies in Yueshan area are generally located at the fold tip and the two flanks, and the contact zone between the Yueshan diorite and the Yueshan formation marble is a necessary condition for mineralization. Two sets of basement faults in NE and near EW direction are two groups of faults in good magmatic channel, NW and near SN, which have a destructive effect on the orebody, the spatial distribution and preservation conditions of the deposit are controlled by fault tectonics. Therefore, the detailed structural analysis of the study area is very important for the exploration of deep orebodies. Based on the study of fold structures in the study area, it is considered that the back slope of Baizishan is NNE.The dip end of the anticline, Yueshan-Loess Mountain anticline, is a favorable metallogenic position. F1 fault is a post-metallogenic fault structure. The fault of F _ 1, which is destructive to ore body, has the characteristics of multi-stage activity, with the horizontal displacement of 200 ~ 400m, which is mainly left line translation. It is inferred that the favorable target area in Wuzhu tip exploration area may be shifted northward. The controllable source audio frequency magnetotelluric method (CSAMTM for short) is based on the obvious difference in electrical properties between ore and surrounding rock. The low resistivity anomaly zone caused by ore body is searched on the CSAMT inversion profile. However, the low resistivity anomaly itself has multiple solutions, such as fault zone and aquifer can also cause low resistivity anomaly, only using the CSAMT method to guide the prospecting is uncertain. Based on the study of the characteristics of the corresponding CSAMT profile curves of the ore bodies found in the adjacent area, it is considered that the CSAMT curve shape is "V" shape low resistivity zone and steeply reduced resistance zone, which may become a favorable exploration site. Collecting 19 borehole data and surface measured data of Wuzhoujian exploration area and adjacent area, the isobath map of the top surface of Yueshan rock body and the isobath map of the top surface of Yueshan formation in Wuzhu tip exploration area were made and projected onto the CSAMT curve section. The geological profile of the CSAMT map is obtained and the ore-bearing CSAMT curves similar to those in the adjacent area are found in the contact zone between diorite and Yueshan formation carbonate rocks. The favorable exploration hole position is proposed. Field geological investigation has determined the fold form of Yueshan-Loess Mountain anticline. The Zhuchong mining area is located on its north west wing, and the Wuzhu tip exploration area is located on its south and east flank. It is known by structural analysis and analysis of favorable parts of ore-bearing structure. In Wuzhu Tien exploration area, there may be a ore body with symmetry with Zhuchong orebody. At the same time, the boreholes designed according to the CSAMT profile are located in the anticline core and the favorable metallogenic position in the east and south wing of the anticline. In this paper, geophysical data and structural geological analysis are effectively combined, which complement each other and improve the reliability of searching for ore-forming targets.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.41

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