节点文献
锡矿山锑矿田多元地学综合信息成矿预测研究
Research of Multiple Geoscience Information Prospecting Prediction in Xikuangshan Antimony Ore Field
【作者】 陈三明;
【导师】 陈建平;
【作者基本信息】 中国地质大学(北京) , 资源与环境遥感, 2012, 博士
【摘要】 “世界锑都”湖南锡矿山锑矿田是华南锑矿带最重要的超大型锑矿田,锑储量占世界锑总量的13.8%以上。然而,矿田经过了百余年的开采,多数矿山资源已濒临枯竭。如何在危机矿山及其外围有效地预测靶区,寻找新的、有价值的锑矿床,已成为当前迫切需要解决的问题。在针对锡矿山锑矿田的区域地质特征、主要控矿因素、典型矿床特征、地球化学异常特征、地球物理异常特征和遥感综合异常特征的研究基础上,遴选、归纳出矿田多元地学综合信息找矿因子,建立基于GIS平台的多元地学信息预测模型,借助于证据权重法和弹性BP神经网络两种非线性预测手段对矿田及其外围进行了成矿预测,对圈定的成矿预测靶区进行了筛选和评价,并对其中的飞水岩预测靶区进行了初步的工程验证,取得了理想的效果,也印证了整套多元地学信息成矿预测体系的合理。本文研究的主要内容以及成果认识有以下三个方面:1.全面整理历史上的所有地学资料,重新分析或补测部分数据,结合野外踏勘及钻探调查,重新厘定成矿机制与成矿规律,获得多个突破传统的新认识。在区域地质、地球物理、地球化学研究的基础上,从矿田的四个典型矿床中总结出成矿的地质特征和成矿规律等成矿地质条件,从而提取找矿标志。经分析得出锡矿山锑矿田与矿化有关的地层主要是上泥盆统佘田桥组的灰岩段(次为砂岩段);矿田基本构造型式为背斜与断层交汇处,深部断裂投影位置至关重要;矿田围岩蚀变主要为硅化蚀变,矿化只限于佘田桥组灰岩段、砂岩段和棋梓桥组灰岩段中的硅化层;锑元素的两性特性决定成矿空间位置主要在氧化带;地磁和重力异常的主要分布于欧家冲和谭家冲之间,延伸在F75大断层下盘;大部分矿点及见矿钻孔出现在地磁高值异常的地带上;结合矿田重力局部低布格异常等多种因素,推断出深部有岩体侵入;Sb、As、Hg等成矿元素化探异常呈面状异常并与已知矿床吻合,且规模大、强度高、浓集中心明显;自然重砂异常基本分布在矿田的四大矿床外围,其基底碎屑岩是锡矿山锑矿的主要成矿物质来源;区域花岗岩及深部隐伏岩体则提供部分矿质和部分矿化剂,矿质运移的热动力源来自矿田深部地壳上地幔、区域花岗岩和深部隐伏岩体。这些改进的认识与观点是成矿模型预测的基础,也是决定预测结果的关键因子。2.改变传统遥感只注重图像分析的提取方式为“先地质、再天上、再地面”的工作模式,通过遥感综合指标异常的提出,探索中大比例尺度范围危机矿山外围遥感信息提取的机理与适用方法。危机矿山都有相当程度的工作积累,遥感因其宏观上的优势需要回答“找什么”的问题,经过全面的成矿规律分析后寻找成矿赋存环境,发现锡矿山矿床一般的赋存空间平面投影在硅化蚀变带与有氧化环境较强的断裂带交汇处,因此遥感要寻找这种特殊的赋存区段。借助于野外地物波谱仪的测试,并建立典型的遥感地质地球化学剖面进行分析。以ASTER遥感影像为基础,分别从可见~短波红外波段提取铁染异常和烃基、碳酸根异常,以两者相除的结果反映出地球化学指标F1(Sb、As、Hg)/F2(Co、Ni、Cr)的分布,也即是氧化环境的宏观量;从热红外波段提取硅化蚀变异常,然后将氧化环境指数与硅化蚀变异常进行交集运算后得到了研究区的遥感综合指标异常。该异常正是根据锡矿山已知矿床的空间赋存环境特征,利用遥感的宏观性有目标针对性地提取的一种新的遥感异常形式,它不仅目标明确,而且充分挖掘了ASTER的全息信息,同时遥感异常的空间展布形态更加连续和完整。因此,在中大比例尺度预测过程中,探索遥感异常信息的目标提取,减少遥感的不确定性因素,对于危机矿山及其外围的遥感预测有着重要的意义,遥感综合指标异常方法如下式所示:(?)为此还针对研究区的地貌,在遥感信息的恢复与提取中改进了BPH植被抑制法和DEM阴影校正法,增强了阴影处及植被下的地物波谱信息。3.依据锡矿山锑矿田的多元地学综合信息找矿模型,利用证据权重法和弹性BP神经网络两种地质数学的预测手段,进行研究区及其外围的锑矿资源的交叉预测,预测的结果经工程验证证明效果明显。在充分分析锡矿山已知矿床的成矿规律后,从众多地学信息中甄别出12个典型找矿因子,在MapInfo11.0平台上运用证据权重法对矿田及外围进行了成矿预测;同时通过改进弹性BP神经网络的收敛算法并编程,利用改进型的弹性BP神经网络预测方法对研究区同样进行成矿预测;然后将两种方法预测的结果相交分析,圈定出3个Ⅰ级和3个Ⅱ级找矿靶区。其中飞水岩矿床边深部靶区(A1)成矿地质条件优越,应当具有较好的找矿前景,工程验证证实了预测的正确性;老矿山矿床边深部靶区(A2)在深部和外围具有进一步的找矿潜力,对童家院以东煌斑岩脉以西和老矿山以北的预测靶区应当重视,特别是52线至82线F75断裂下盘区域,有可能成为锑矿田的第四大成矿中心。实践证明,危机矿山由于历史资料沉淀,专家观点各异,多元信息丰富,必须要借助于GIS的综合地学信息矿产综合预测方法,而且用双手段交叉预测的类似“两只眼睛”的方法更能捕捉到感兴趣目标。同时,在充分研究矿田的成矿规律和赋矿空间特征的基础上,利用ASTER的遥感全息提取方法得到的遥感综合指标异常,具有目标导向且针对性强的遥感信息提取的特点,对中大比例尺度下危机矿山外围及深边部找矿的宏观预测具有重要的作用。
【Abstract】 "The world antimony city"Hunan of Xikuangshan antimony deposits in Southern China antimony ore belt is the most important super large antimony ore field of antimony, antimony reserves of the world for more than 13.8% of the total. However, after a hundred years of mining ore field, the majority of mine resource is close to dried up. How the crisis mines and its peripheral effectively predict target area, looking for new, valuable deposit, has become an urgent problem to be solved.In the light of Xikuangshan antimony ore field regional geological features, ore controlling factors, the main characteristics of typical deposit, geochemical anomaly, geophysical anomalies and remote sensing synthetic characteristic of anomalies on the basis of the study, summed up the ore field, the selection of multiple geoscience information prospecting factors, based on the GIS platform of multiple geoscience information predicting model, with the help of weights of evidence method and resilient BP neural network nonlinear predictive means two for ore field and its peripheral of metallogenic prediction, to locate the metallogenic prediction target area were screened and evaluated, and the flying water rock predict target area undertook preliminary engineering verification, the ideal effect has been achieved, also confirms set of multiple geoscience information metallogenic prediction system reasonable.This article studies the main content and the results are the following three aspects:1.Comprehensive history on all data, to analysis or supplement measurement data, combined with field survey and drilling survey, the redefinition of metallogenic regularity and metallogenic mechanism of, access to a number of traditional knowledge.In the regional geological, geophysical, geochemical research foundation, from four typical ore deposits in the ore field are summarized metallogenic geological characteristics and metallogenic regularity and metallogenic geological conditions, thereby extracting the prospecting marks. By analyzing of Xikuangshan antimony ore field and mineralization related strata are mainly the upper Devonian She Tianqiao group limestone part (for sandstone); basic tectonic pattern for orefield anticline and fault interchange, deep fault projection position is crucial; ore wallrock alteration mainly silicification, mineralization is confined to She Tianqiao group limestone, sandstone and chess Catalpol Bridge Group limestone in the silicide layer; antimony element amphoteric characteristics determine metallogenic spatial location in oxidation zone; magnetic and gravity anomaly is mainly distributed in the European family of punch and Tan Jiachong, extending in the F75 big fault footwall; most ore and ore hole appeared in the geomagnetic high value anomaly zone; combined with the field of local gravity low Bouguer anomaly and other factors, to infer the deep intrusive; Sb, As, Hg etc. metallogenetic element geochemical anomalies in facial abnormalities and known deposits anastomosis, and large size, high strength, obvious concentration centers; natural placer mineral abnormalities underlying distribution in in four large deposit periphery, the basal clastic rocks are mainly in Xikuangshan antimony deposit ore-forming source; regional granites and deep concealed rock provides some mineral and some mineralizer, mineral Migration from thermal power in deep crust and upper mantle, regional granites and deep concealed rock mass. These improved understanding and perspective is a metallogenic model prediction based, also decided to predict the outcome of the key factor.2.change the traditional remote sensing image analysis of the extraction of only pay attention to the way for the" first, and then the sky again ground geological, " mode of operation, through remote sensing comprehensive indices of abnormal raised, exploration of crisis mines in large scale range of peripheral information extraction mechanism and application method.Crisis mines have a considerable degree of accumulation, remote sensing due to its macroscopic advantage needs to answer the" what", after a comprehensive analysis of metallogenic regularity of looking after mineralization environment, found in Xikuangshan deposit general occurrence space plane projection in silicification belt and has strong oxidation environment fracture zone interchange, the remote sensing to find this special occurrence section. By means of field spectral instrument testing, and the establishment of a typical remote sensing geological geochemical profile analysis. Remote sensing image based on ASTER, respectively, from visible to infrared band extraction iron staining of abnormalities and alkylene carbonate, abnormal, which eliminate the results reflect the geochemical index F1 (Sb, As, Hg)/F2 (Co, Ni, Cr) distribution, that is the macroscopic quantities from oxidizing environment; thermal infrared anomaly extraction silicification, and then oxidizing environment index and silicified alteration anomaly was obtained after the intersection of the study area remote sensing abnormal index. The exception is the basis of Xikuangshan known deposits distribution in space environment characteristics, using remote sensing macro is targeted to a new extraction of remote sensing anomaly form, it is not only clear goals, and fully tap the ASTER holographic information, at the same time remote sensing anomaly spatial distribution patterns were more continuous and complete. Therefore, in the large scale prediction process, exploration remote sensing anomaly information extraction of remote sensing target, reduce the uncertainty factors, for crisis mine and its peripheral remote sensing prediction has important significance of remote sensing anomaly, comprehensive index method the following:F (x)=a silicification and a iron staining of abnormal/a (hydrocarbyl carbonate mineral cluster+group)This is based on the landform, the recovery and extraction of remote sensing information to improve BPH vegetation inhibition method and DEM shading correction method, enhanced the shadows and vegetation of spectral information. 3.on the basis of the Xikuangshan antimony ore field of multiple geoscience information prospecting model, using weights of evidence and resilient BP neural network two kinds of mathematical geology prediction method, conducts the research area and its periphery ore cross prediction, forecasting results engineering verification shows that the effect is obvious.In the full analysis of the Xikuangshan known deposits metallogenic regularity, from numerous geological information identify 12 typical ore factor, in the MapInfo1l.0 platform using weights of evidence method to ore field and peripheral of metallogenic prediction; at the same time through improved resilient BP neural network algorithm and programming, using the improved resilient BP neural network method for the prediction of the study area was the same metallogenic prediction; then two methods to predict the results of analysis of the intersection, the delineation of 3 grade and 3 gradeⅡprospecting target area. The flying water rock deposit deep of edge of target zone (A1) metallogenic geological conditions, should have a good prospect, engineering verification confirms the validity of prediction; old mine deposit deep of edge of target zone (A2) in the deep part and periphery has further prospecting potential, to Tong Jiayuan in brilliant class the dikes and the old mine to the North West of the prediction of target area should pay attention to, especially the 52 line to 82 line F75 faulting footwall area, may become the fourth major mineralization center of antimony ore field.Practice has proved, the crisis mines due to the historical data of precipitation, experts hold different views, multivariate information rich, must with the aid of GIS synthetic information mineral resources comprehensive prediction method, and with both section cross prediction of similar" two eyes" method can capture the interested target. At the same time, in the full study in the metallogenic regularities and ore spatial characteristic in the foundation, use ASTER remote sensing extraction method to get holographic integrated remote sensing abnormal index, with goal orientation and targeted extraction of remote sensing information features, in large scale crisis mine periphery and deep side prospecting macroscopical forecast has an important role in.
- 【网络出版投稿人】 中国地质大学(北京) 【网络出版年期】2012年 09期
- 【分类号】P618.66
- 【被引频次】1
- 【下载频次】809
- 攻读期成果