【作者】 张义；

【导师】 聂凤军；

【作者基本信息】 中国地质科学院 ， 矿物学、岩石学、矿床学， 2006， 博士

【摘要】 本文以莫若格钦银铅锌矿化带为研究对象,研究了区域地质背景、主导控矿因素和找矿标志的提取技术,建立成矿区(带)、矿田和矿床(体)多级别矿化、多种信息预测评价模型;评价了成矿区(带)的成矿前景和找矿潜力,指导矿床勘查工作。文章全面收集和综合了以往地、物、化、遥和矿产资料数据,以活动大陆边缘沟-弧-盆学说和碰撞造山理论为指导,从研究大地构造格局和时空演化入手,分析了莫若格钦银铅锌矿化带找矿方向。研究工作以中-大比例尺地质填图为基础,先后开展了109.48km2比例尺为1∶50000的地质填图、24km2比例尺为1∶10000的地质填图和2.4km2比例尺为1∶2000的地质填图工作;综合应用了化探岩屑测量、物探地面高精度磁法测量、大功率激发极化法测量、激电测深、高密度电法测量和连续电导率成像(EH4)测量等手段。本论文还首次在莫若格钦地区进行了PIMA测试方法实验,全面采集了莫若格钦银铅锌矿化区各种找矿方法的信息资料。地质填图工作中发现了一条强烈绢云母、褐铁矿化带,该带在奥陶纪和泥盆纪地层中都非常发育,矿化带受北北东向构造控制明显。1∶2000地质填图细化了马西巴图山地质和矿体的空间分布。并在岩石类型、蚀变带分布等方面取得了深入的研究和新的进展。化探岩屑测量在采样介质粒度上做了大量的研究工作,选定-4～+20目粒度的介质作为研究区采样对象,化验结果大大提高了异常提取的衬度。在93km2范围内圈定了9个化探综合异常区,多数异常区具有多元素组合的特点,异常规模大,强度高,主要成矿元素在分布上具有分带性。物探磁法测量在30km2测区内圈定出3个磁异常高值区;激发极化法测量圈出9个极化率异常带,其中低阻高极化带5个、中阻中极化带2个、高阻中极化带2个。具体来讲,在布哈达山预测区含有4个呈串珠状排列的低阻高极化异常带。马西巴图山预测区含有2个中-高阻中极化异常带呈弧形分布在印支期岩体的外接触带。进一步的高密度电法测量和EH4测量都获得了明显的异常体显示。PIMA测量在研究区内确定了强绢云母化带、强绿泥石化带、强蒙脱石化带和高岭石化带的分布范围,并且指出了蚀变矿物形成温度降低的方向。在此基础上,建立了三维多级别矿化单元、多元信息预测评价模型,将地质、物探、化探找矿标志和矿化单元勘查工种作为自变量的二维数轴,再将各找矿标志分为三个等级,给出预测区评价意见。野外调查并结合室内研究,在莫若格钦银铅锌矿化区确定了6个不同类别的预测区,其中布哈达山和马西巴图山是目前最有远景的找矿区(A类),莫若格钦铜银矿化点和乌兰敖包预测区属于有远景的预测区段(B类),沙尔布若图诺尔和阿尔布朗预测区是较有找矿远景的预测区(C类)。主导控矿因素是燕山早期岩浆岩和同生断裂构造。成矿物质来源于具有从印支期继承性活动特点的岩体,而断裂构造则成为成矿物质的导矿和容矿空间。更多还原

【Abstract】 The study area, Moruogeqin Ag-Pb-Zn mineralized belt, is a new polymetallic mineralized zone discovered in Moruogeqin district, eastern Inner Mongolia. Regional geological setting, major ore-controlling factors, and the extracting technology of ore guide of the Moruogeqin mineralized belt were studied in this work. Further, a multivariate prognostic model based on multidimensional framework was found. Moreover, based on these work, the ore-forming prospect and ore-finding potential of the Moruogeqin mineralized belt were evaluated.Previous geological, geophysical, geochemical, remote sensing and mineral resources data of the Moruogeqin district were collected and analyzed systematically. According to the active continent marginal trench-arc-basin theory, combining with the spatial and temporal evolutionary history of regional tectonic setting, the ore-finding orientation was put forward in the study area. Geological mapping at middle- and large-scale, geochemical and geophysical survey were carried out in this study. On the aspect of geological mapping, 109.48km2 at 1:50,000, 24km2 at 1:10,000 and 2.4km2 at 1:2000 were implemented. On the aspect of geochemical survey, debris survey in the Moruogeqin district was carried out. On the aspect of geophysical survey, ground high-precise magnetic prospecting, large-power induced polarization prospecting, high-density electrical method and EH4 survey were being done. In addition, a new geological instrument used for alteration mineral mapping, PIMA, was be used in Moruogeqin district firstly. Consequently, the information of alteration minerals in Moruogeqin Ag-Pb-Zn mineralized belt was comprehensively gathered.A few strong sericite and limonite alteration zones, which developed both in Ordovician and Devonian strata, were discovered during the detail geological mapping, and it is distributed along NNE-trending fault obviously. The mapping at 1:2000-scale exactly determined the geological characteristics and distribution of ore body in Maxibatushan district as well as made process in rock types and distribution of alteration zone. Considerable study has been done for scale of sampling medium in geochemical exploration by cuttings, then medium of -4~+20 mesh were selected as sample object in the study area. The results show that extracts abnormality has been strongly raised by adopting these samples. There are 9 elements overlying geochemical abnormal zones outlined in scope of 93km2, most of those with character of multi-element, large size and high intensity, and the distribution of mainly mineralization elements well-zoned. Three magnetic anomaly zones were outlined in scope of 30km2 by magnetic surveying. Nine polarizabilitic anomaly belts were outlined by using induced polarization method, including five low-resistivity and high-polarizabilitic anomalous areas; two moderate-resistivitic and moderate- polarizabilitic anomalous areas, and two high-resistivitic, medorate-polarizabilitic anomalous areas. There are four low-resistivitic, high-polarizabilitic anomalous areas which arranged like strings of beads in Buhadashan prospect. There are two moderate-high-resistivitic and moderate-polarizabilitic anomalous areas which located at excontact embayment of Indosinian intrusions in Maxibatushan prospect. Further high-density electrical survey and EH4 survey both indicated visible anomaly. Distribution of strongly sericite altered zone, chlorite altered zone, montmorillonitized zone and kaolinized zone within study area were defined by PIMA survey, and the declining orientation of temperature at which altered mineral formed were pointed out. The multivariate prognostic model, with various ore-finding guides and various mineralized units types as independent variable 2-dimensional axis, according to the expert’s experience model, proposed the evaluation of the prospecting district. Combining detailed field work with in-door analyses, six prospecting area were determined in Moruogeqin Ag-Pb-Zn mineralized belt, which can be classified as A, B and C three types. Buhadashan and Maxibatushan prospecting area belong to the A type, and are the best area have mineralization potential. Moruogeqin Cu-Ag mineralized spot and Wulan aobao prospecting areas belong to the B type, and are the better areas which have mineralization potential. Sharburuotunuor and Aerbulang prospecting area belong to the C type which has the potential area. The major ore-controlling factors in Moruogeqin district are the early Yanshanian magmatic rocks and contemporaneous faults. The ore-forming materials derived from the early Yanshanian intrusions, and the contemporaneous faults are the transporting and deposition space for ore-forming fluids.更多还原