【作者】 张爽；

【导师】 鲍征宇；

【作者基本信息】 中国地质大学 ， 地球化学， 2013， 博士

【摘要】 位于欧亚板块东南端的南岭成矿带(北纬24°-27°,东经110°-115°)是我国重要的钨锡矿产地,该区经历了晋宁、加里东、海西-印支、燕山-喜马拉雅四个构造发展阶段,广泛发育四堡期至燕山期构造-岩浆-成矿活动频繁,并以燕山期花岗质岩浆活动最为强烈且与钨锡矿成矿最为密切。区内寒武系、泥盆系、石炭系被探明是钨锡矿的重要赋矿层位,已探明了包括大厂、骑田岭、西华山、柿竹园、大吉山等在内的著名大型-超大型钨锡矿床,使得该区成为研究钨锡矿床成矿机理及开展钨锡矿产勘查技术建立的理想地区。近年来,随着我国国民经济发展对钨锡矿产需求的持续增长,加之南岭地区钨锡地表矿和浅部矿的长时间开采,钨锡矿储量逐年减少。因此,寻找该区可能存在的隐伏钨锡矿体,已被提升为解决当前我国矿产资源紧缺、实现资源矿产可持续发展的重要议程之一。尽管目前在南岭重大基础地质问题、区域成矿规律等方面取得了大量的成果,但在钨锡矿地球化学勘查方面仍然存在(1)1：20万化探数据成果有待更新,1：5万化探数据资料不足,这些数据对隐伏矿的指示效果有待明确；(2)缺少对区域化探数据处理方法较为深入的研究；(3)地球化学找矿新方法在该地区隐伏矿勘查中的应用较少等多方面的问题,这限制了我们对南岭钨锡矿分布的全面认识和深部隐伏矿体勘查的效果。鉴于此,发展有效的隐伏矿勘查方法体系显得尤为重要。本研究利用原有1：20万化探数据和新完成的1：5万化探数据共完成近百幅地球化学图或异常图的绘制。另外完成了800余件土壤剖面样品和46件岩石样品的采集及测试分析工作以及土壤剖面异常图的绘制。包括：(1)南岭地区1：20万化探数据中W和Sn相关元素的二次整理和成图及指示信息的提取,分析该组元素对钨锡矿的指示效果。(2)选取该区一个重要成矿区带铜山岭-九嶷山地区1：20万化探数据异常图不同方法的对比,包括子区中位数衬值滤波法、背景校正法和因子分析法进行1：20万化探数据处理。(3)铜山岭-九嶷山地区1：5万化探数据信息的提取。通过元素异常图选取出对隐伏矿体有指示意义的元素。(4)地球化学找矿新方法对铜山岭-祥霖铺矿区隐伏矿指示效果的试验。包括烃气测量、元素活动态测量等方法。获得了如下认识：(1)在整理南岭地区1：20万化探数据的基础上,通过聚类分析发现,研究区元素主要可分为四组,包括造岩矿物常见元素组、与成岩过程-岩浆分异程度有关的元素组、以W、Sn为主的成矿元素组和以铜铅锌成矿元素组。选择W、Sn成矿元素组内的十三种元素(Au、Ag、Cu、Pb、Zn、As、Sb、F、Ba、Mo、Bi、Be、B),运用小波分析滤波的方法绘制地球化学图,发现W、Sn元素的高值区域主要分布在区内与成矿有关的各侵入岩体附近,且在研究区的东南部浓集中心较多。位于研究区中心的郴州-桂阳地区是各个元素的浓集中心。为了消除大范围区域化探中各种地质因素的影响,带入更多的综合信息,首先绘制单元素的衬值异常图,然后计算各元素衬值的等权平均组合元素异常图。异常基本上分为常宁-大余和新宁-始兴两个分带,与该区内隐伏岩体的分布吻合。该方法确立的异常范围相对单元素减小,更容易确立靶区,并且带入了更多的信息。(2)铜山岭-九嶷山成矿带位于南岭中段,都庞岭复式花岗杂岩体和铜山岭花岗闪长岩体与九嶷山复式花岗杂岩体构成了东西向花岗杂岩带,控制了区内钨锡多金属矿的展布。区内钨锡资源丰富,已知矿点多分布于铜山岭岩体、祥霖铺斑岩群和金鸡岭岩体。本研究总结了该区内主要的矿床和矿化点。在对区内1：20万化探数据统计的基础上,用传统方法(均值±2标准差)、子区中位数衬值滤波法和结合Mapgis数字高程模型的背景校正法绘制与W和Sn相关元素的地球化学异常图。其中子区中位数衬值滤波法选用3x3单位格子作为小窗口和9×9个单位格子作为大窗口。与传统方法对比,衬值滤波法缩小了异常面积,圈出了部分低背景区域的异常。但是以衬值为基础的计算方法可能过分夸大低背景区元素含量的不明显变化,而以残差作为计算方法更能真实反映元素的矿化叠加值。通过窗口对比试验,选取7x7的窗口更具有充分发掘低缓异常突出重点高背景矿致异常的效果。通过背景校正的方法抑制了高背景区的非矿化异常,强化了弱异常,并发现了一系列新异常。因此背景校正法在该区的化探数据处理中更具有优越性。但是由于1：20万化探数据采样密度低等原因,一些出露面积较小的成矿岩体和隐伏矿容易被遗漏。另外为了寻找控制研究区矿化规律的因素,对与钨锡相关的元素进行因子分析，提取出4个公因子,分别为铜铅锌矿化因子、钨矿化因子、锡矿化因子和矿化剂因子。并且钨矿化因子集中于西南部,锡矿化因子集中于东北部,铜铅锌矿化异常面积和强度相对钨锡矿化均较小。(3)铜山岭-九嶷山地区1：5万化探数据分析结果表明,该组数据受区域地质等原因影响来自两个母体,因此将其分为两个群体分别计算衬值,然后绘制总体的衬值异常图。在计算过程中利用Excel中VBA编程,实现在Excel中绘制分形图和箱图,并计算元素背景值和异常下限,简化了地球化学数据的处理过程。从元素异常剖析图可以看到,W、Sn、Mo、Bi、F组合异常主要出现在祥霖铺、铜山岭、九嶷山和后江桥地区。可见该组元素对钨锡矿的指示效果较好。而Cu、Pb、Zn、Sb元素在铜山岭、九嶷山和后江桥的组合异常面积较大,也与已知铅锌矿点吻合。预测该区钨锡矿和铅锌矿成矿潜力较大。(4)祥霖铺-铜山岭成矿区主要受样霖铺斑岩群和铜山岭岩体的控制,其中魏家钨矿产出于祥霖铺斑岩群,为隐伏矽卡岩型矿床,常规指示元素找矿效果不明显；而铜山岭岩体周围的江永铅锌矿和铜山岭有色金属矿开采多年,也面临着在矿山外围和深部寻找隐伏矿的问题。本研究通过在两个矿区的烃气测量、汞气测量和金属元素活动态测量,选取有效的隐伏矿勘查手段。通过对南岭魏家隐伏矽卡岩型钨矿见矿钻孔ZK801岩心酸解烃和铜山岭-祥霖铺矿体上方土壤热释烃的研究,发现在岩心围岩、蚀变围岩、矿体和斑岩体中烃类组分有规律的变化,并且低异常值比较准确地指示了矿体的位置；烃类组分在不同成矿层位配分曲线特征不同,从而指示了成矿物质来源；利用碳同位素示踪土壤中热释烃来源对与地球化学勘查工作具有重要的意义,对蚀变围岩和矽卡岩矿体和花岗斑岩岩心样品的甲烷碳同位素的初步测试也为该项工作提供了一定参考,但是由于岩心中重烃和土壤中烃气含量较低碳同位素未能检测出；土壤热释烃在深部隐伏矿体上方呈双峰分布,低值区域对应了矿体的位置,而常规指示元素只在浅部钨矿体上方有明显的异常,两者相比烃类组分对深部隐伏矿有更好的预测效果；对于铜山岭有色矿区,土壤热释烃也在矿区两侧出现峰值,尤其是丁烷的效果最为明显。对于魏家钨矿元素活动态对钨矿体的指示效果实验研究表明,所测几种元素As、Sb、Cu、Pb、Zn除Pb元素外绝大部分以残渣态存在,单纯元素活动态含量对浅部的矿体有较好的指示意义,但是对于深部隐伏矿体则效果不明显。统计活动态元素所占总量的百分比之后,发现在隐伏矿体上方大部分元素活动态比率呈现比较明显的上升趋势。此项指标可以作为今后元素活动态对隐伏钨矿指示研究的一个方向。通过以上研究,本文从大的南岭钨锡成矿带到典型矿床,由面及点,较为系统的研究了南岭钨锡矿的指示元素及地球化学找矿新方法的应用效果。选取的钨锡元素组衬值异常图可以有效的指示矿点,并且在铜山岭-九嶷山地区有较为明显的效果。而通过在铜山岭-九嶷山地区不同数据处理方法的对比,认为背景校正法在区域化探数据处理中具有优越性,并通过元素异常图确定了都庞岭、铜山岭和九嶷山地区的成矿潜力。最后在典型矿区祥霖铺-铜山岭针对隐伏矿试验的地球化学找矿新方法也取得了较好的效果,可以进一步应用到实际工作中。本论文研究对南岭地区钨锡矿进一步的勘查工作具有一定的参考意义。但是由于时间有限,本研究还存在一些不足。今后应在以下几方面开展深入的的研究工作：南岭地区钨锡矿指示元素针对隐伏矿进一步的总结应用；对铜山岭-九嶷山表现出的不同异常范围和强度可以从岩体性质和隐伏岩体等方面做进一步的解释：对于碳同位素的示踪应开展进一步的研究：在元素活动态方面应尝试更多元素相态的测试,尤其是钨锡活动态的测试工作；最后针对隐伏钨锡矿应进一步开展多种隐伏矿勘查方法的试验工作。希望通过这些问题的解决、方法的试验等,可以推动南岭地区钨锡矿勘查的研究工作。更多还原

【Abstract】 Nan-ling metallogenic province is located in the southeast of Eurasian plate.It has experienced four stages including Jin-ning period, Caledonian period, Hercynian-Indosinian period and Yanshan-Himalaya period. Cambrian, Devonion and Carboniferous are the important tungsten-tin ore bearing stratums in this area. Tectonic, magmatic and metallogenic activities occurred frequently and intensively in this region during Sibao to Yanshan periods, and the most intensive of them is the Yanshanian granitic magmatism, which is closely related to the metallogenesis of tungsten and tin deposits.This area is an important tungsten-tin orefiled of China where many large and super-large ore deposits such as Da-chang, Qi-tianling, Xi-huashan, Shi-zhuyuan and Da-jishan tungsten-tin deposits have been targeted. Basing on the previous detailed geological, geophysical and geochemical study, Nan-ling is an ideal area for geochemincal exploration study.With the development of national economy, the demand of tungsten-tin mineral resources is growing continuously. But the reserves of surface mine and shallow mine are decreasing for long term mining activities. To solve the resource prolems, the exploring work of buried deposit is an useful method. Though there are many achievements about the basic geology and metallogenic regularity in this area, the geochemincal exploration of tungsten-tin deposits needs further study:(1) the geochemincal exploration data at1:200,000scale needs to be updated and the geochemincal exploration data at1:50,000scale is lacking. Can the geochemincal exploration data indicate the concealed mine is not clarity.(2) the data processing method of the regional geochemincal data need to be developed.(3) the application of new geochemincal exploration methods have been rarely used in the area. These issues limit our understanding of the distribution of tungsten-tin deposits and how to prospect the consealed mine.Aming at the above problems, the thesis establishes a series of exploration methods. First, in the Nan-ling area, a group of elements related to W and Sn element are selected through cluster analysis. The geochemical maps of these elements and geochemical anomaly maps of contrast values were generated to help us understading the elements distributon and indicating effect tungsten-tin deposit. Second, Tong shanling-Jiu yishan metallogenic belt in Nan-ling area is selected. Subinterval area median contrast filtering method, background correction method and factor analysis were carried out to generate the geochemical anomaly maps at1.200,000scale. And then the geochemical anomaly maps of single and integrated elements at1:50,000scale were generated to find the useful indicator elements for tungsten-tin deposits. At last the new exploration methods like hydrocarbons and mobile forms of metals methods were used in Tong Shanling-Xiang Linpu mining area. In this work,about a hundred geochemincal anomaly maps of elements were generated at1:200,000scale and at1:50,000scale. Additionally, about800soil samples and46core samples were collected and analysed. The detaile work and results are stated in the following:(1)Through processing the exploration data of nanling at1:200,000scale by cluster analysis, it’s found that the elements in the research area can be divided into four groups:the common element-group for Rock-forming mineral, the element-group related to diagenetic process and magma splitting degree, the tungsten-tin ore-formation element-group, the copper-lead-zinc ore-formation element-group mainly. Using the cotent values of thirteen elements (Au, Ag, Cu, Pb, Zn, As, Sb, F, Ba, Mo, Bi, Be, B) in the tungsten-tin ore-formation element-group and copper-lead-zinc ore-formation element-group, geochemical maps are generated based on wavelet analysis-filtering. It’s found that the high value area is mainly distributed around the rock mass, and the high values in the study area appear more in the south-eastern. Most of the high values of every element are mostly located in Chenzhou-Guiyang area, which is in center of the study area. To avoid the influence of different geologic factors in large-area regional geochemical exploration and take in more comprehensive information, anomaly maps for contrast values of single element are generated firstly. Then the anomaly maps of equal weighting contrast values of every element were generated. The anomalies can be divided into two zones:Changning-Dayu zone and Xinning-Shixing zone, and their distribution agree well with the location of the concealed intrusive bodies. By this method, the anomaly extension determined is smaller than anomaly maps of single element contrast value, and it’s easier to identify the targeted area. Additionally it brings in more comprehensive information.(2) Tong Shanling-Jiu Yishan metallogenic belt is located in the center of Nanling. The EW granite complex belt, which controlling the distribution of W-Sn polymetallic deposits in the area, is consist of Du Pangling composite granite rock, Tongshanling granite diorite rock and Jiu Yishan composite granite rock. W-Sn resources are rich in this area and most of the known mines locate in Tong Shanling magmaticbody, Xiang Lingpu porphyry group and Jin Jiling magmaticbody. This study summarized the major point of ore deposits and mineralization in the district. Basing on the1:200,000scale geochemical exploration data, the geochemical anomaly maps of W, Sn and the other elements related to W-Sn are generated using the traditional method (mean±2standard deviations), subinterval area median contrast filtering method (SAMCF) and background correction with digital elevation model in Mapgis software.3×3grid for small window and9×9grid for large window are used in subinterval area median contrast filtering method. Compared with the traditional method, the size of anomaly areas are reduced and some anomalies in low background are delineated by SAMCF. But this contrast calculation method may exaggerate the unobvious change of element content. And the residual will be better to show the elements of the superposition of mineralization. Through the contrast test of window, the window with7×7is better in disinterring the weak anomalies and highlighting the mineralization anomalies in high background. By using the background correction, some nonmineralized anomalies in high background are restrained and some weak anomalies are strengthened, as well as a series of new anomalies are found. Therefore, the background correction has more superiority in processing this geochemical exploration data. Because of the low sampling density of1:200,000scale geochemical exploration data, some metallogenic rock body with less outcropped and conceal deposits are easily missing. In search of the control factors of mineralization regularity in this study area, four factors, which include Cu-Pb-Zn mineralization factor, W mineralization factor, Sn mineralization factor and mineralizer factor, are extracted by factor analysis. W mineralization factor concentrates in southwest and Sn mineralization factor concentrates in northeast. The size and intensity of anomalies of Cu-Pb-Zn mineralization are lesser than W-Sn mineralization.(3) The results of geochemical data analysis at1:50,000scale in Tong Shanling-Jiu Yishan area show that this group of data is influenced by the regional geology and comes from two different geochemical matrixs. So it should be divided into two groups and calculate the contrast value respectively. Then draw the anomaly map of contrast value of every element in the whole area. With writing VBA programs in Excel, drawing the fractal figure and box plots in Excel were realized. And the background values and anomaly threshold of elements were calculated in Excel, too making the processing of geochemical data simply. From element anomaly maps it can be seen that W, Sn, Mo, Bi and F composite anomalies mainly appear in the Xiang Linpu, Tong Shanling, Jiu Yishan and Hou Jiangqiao area. The elements group indicates tungsten-tin deposit obviously. The area Cu, Pb, Zn and Sb element composite anomaly is larger in the Xiang Linpu, Tong Shanling, Jiu Yishan and Hou Jiangqiao area. It is also in accordance with the known lead-zinc mine. There is potential for the prospecting of tungsten-tin deposit and lead-zinc deposit in this area.(4) Weijia tungsten ore is located at Xiang LinPu Town, Hunan Province. It is in the Xiang Linpu porphyry groups near the Tong Shanling porphyry. The large skam type deposit was detected using comprehensive exploration method during the recent exploration activities in China. Being buried deeply in500m and covered by limestone and thick soil in the surface, it is hard to be detected by traditional indicator elements. Jiang Yong lead-zinc deposit and Tong Shanling nonferrous metals deposit have been exploiting for many years. It is necessary to explore buried mines around or in the deep of the old mine. It is proved that hydrocarbons promoted the transport and enrichment of elements in the ore forming, so Weijia tungsten ore and Tong Shanling diggings are taken as a case to study the effect of hydrocarbons to the concealed deposits in coverage area. Acidolysis hydrocarbon of46rock samples in ZK801and heat release hydrocarbon of soil profiles were analyzed. The results show that the contents of hydrocarbons decrease from porphyry, ore body to wall rock, and the rates of methane, olefins and heavy alkane are different in porphyry, ore body and wall rock. The standard curves shapes of ore are similar to those of the porphyry and wall rock. The soil heat release hydrocarbons show bimodal distribution and low value above the ore body. This study proves that the hydrocarbons are more useful to indicate the concealed mine than the traditional indicator elements. For the mobile forms metal method, the contents of every element species in the soil can indicate the shallow ore body but not for the deep one. But the percentage of element species increase above the deep ore body obviously. So this discover may be a useful method for deep mine detecting in the future.Through the above research, this paper did a systematic research on the indicator elements and new geochemical prospecting method application for tungsten-tin deposit in Nanling area. However, there are still some deficiencies in this study. Further research should be carried out in the following aspects:The indicator elements should be further studied and be applicated for concealed deposits in Nanling area; To explain the reason why Tong Shanling area and Jiu Yishan area show different anomaly range and intensity, more work should be done in the rock properties and concealed rock mass; Further research should be carried out in the carbon isotope to tracing the source of hydrocarbon; About the mobile forms of metals in soil, we should try with more elements, especially in the analysis of speciations of tungsten and tin element; Finally more experiments about various concealed deposit prospecting methods should be carried out.更多还原