【作者】 孟贵祥；

【导师】 裴荣富； 吕庆田；

【作者基本信息】 中国地质科学院 ， 矿产普查与勘探， 2006， 博士

【摘要】 论文研究内容主要结合国土资源部科技与国际合作司的专项研究“中国重要成矿带找矿模型及技术方法”下属的“大型矿集区深部精细结构与成矿研究”(编号：1212010561607)。大型矿集区接替资源定位预测研究多年来一直是现今地学勘探领域的热点和前沿。大型矿集区是矿产资源产出的重要基地，对满足国家经济持续健康发展有十分重要的意义，大量的勘探事实说明，在己开发老矿山(或矿集区)的深部和外围发现新矿床、扩大资源储量有较大的潜力。加强对矿集区接替资源的研究和勘探评价是扩大矿产资源储量的重要途径，对缓解目前老矿山的资源危机意义重大。接替资源定位预测研究的焦点在于如何寻找隐伏矿?如何对隐伏矿进行定位预测研究?对国内外隐伏矿定位预测研究发展现状及我国建国以来隐伏矿的发展过程的分析表明，我国隐伏矿定位预测理论研究是应用综合技术方法定位预测的基础，目前急需结合成矿理论加强综合方法技术优化组合的研究。通过对隐伏矿找矿与大比例尺定位预测的现状进行了总结和探讨，阐述了开展隐伏矿找矿的基本思路为：必须首先加强地质基础理论的研究，拓展找矿新思维，同时坚持综合方法技术勘查，充分利用新方法、新技术；探讨了进行隐伏矿大比例尺定位预测的具体手段，提出在开展重要成矿带中比例尺(1：50000)综合立体成矿预测和大比例尺(1：2000～1：10000)立体地质填图中应加强综合物探的作用。应用先进的三维地质建模软件，初步建立了中比例尺狮子山矿区(1：50000)和大比例尺(1：10000)的冬瓜山矿床的三维立体地质模型。从矿田分布看，铜陵大型矿集区内由西向东依此为铜官山、狮子山、新桥、凤凰山和沙滩角五大矿田。其中狮子山矿田是我国目前勘查研究程度最高的地区之一，是进行隐伏矿定位预测深入研究的理想场所。岩浆侵位和矿田以及矿床的产出主要受近东西向的基底断裂与其上盖层的北东向构造控制。铜陵矿集区在矿田和矿床尺度上，位于表壳浅带的“行、列、汇”构造样式是热液脉型矿床(体)的重要控矿构造，而不同尺度控矿构造的有机结合，则是该类型矿床形成的最重要的构造机制。根据控矿特征，矿田构造可分为浅带“行、列、汇”构造样式、中带岩浆侵入接触构造体系和深带“隆中凹”构造，三者的深度分别为0～1km左右、1～3.0km左右和＞3.0km，在空间上构成了矿田构造的垂直分带。浅、中、深控矿构造带在不同的矿田常具有不同的组合形式，当三者完全产出时则构成了完整的矿田构造垂直分带。分析了狮子山矿田的成矿地质条件、矿床成因，确定了地层、岩体、构造等控矿因素与隐伏矿的关系，通过对冬瓜山及东狮子山典型铜矿床的解剖和对已建立的狮子山矿田“多层楼”或“多位一体”成矿模式的研究，结合地球物理、地球化学特征，总结了地物化综合找矿方法和标志。本次研究的主要内容是依据地球物理探测成果，在基础地质、物化探研究的基础之上，充分结合已有的研究成果，运用和引进新的高精度地震和电磁法等勘探技术进行深部隐伏矿定位预测研究，同时注重对老资料的的客观性评价研究，关注覆盖区隐伏矿的定位预测研究。通过对60km深地震反射剖面数据的分析处理和已有资料的综合解释，查明铜陵矿集区总体呈双层地壳结构，地壳厚约31-33公里，下地壳厚度变化较大(10-20km)；发现矿集区北部下地壳(4-11s，TWT)呈现多组倾向相反的“层状”强反射，是伸展环境下岩浆多次底侵的直接证据。发现矿集区上、下地壳之间(4-7s，TWT)存在向南倾斜的巨型强反射带，证实上下壳之间存在巨大规模的拆离带。该拆离带为岩浆侵入和岩浆房发育创造了空间条件，从而使矿集区下形成巨型穹隆状岩基。发现铜陵矿集区上地壳出现由褶皱、冲断和侵入构造造成的复杂的弧形反射，在复杂弧形反射下方出现反射透明区，证实了浅部巨型岩浆房的存在。数值模拟结果表明，始于浅部巨型岩浆房的岩浆侵入活动，整体上，“深部在中间集中，浅部向两侧扩散”。该巨型岩浆房从根本上控制了铜陵矿集区燕山期构造—岩浆—热液成矿作用。通过狮子山高分辨率反射地震和层析成像研究，初步查清矿集区主要含矿层位和含矿建造(如五通组顶面)的空间展布形态，对深部找矿具有重要的指示意义；发现上地壳盖层出现非耦合变形，强—弱地层在变形过程中形成层间滑脱带。揭示出层间滑脱带为低粘度岩浆和含矿气液的重要通道。在综合分析和研究狮子山矿区地物化综合信息的基础上，建立了隐伏矿定位预测的重磁找矿模型，在预测区开展了以找深部及边部隐伏矿的综合高精度重、磁和电法新技术勘探研究，并依据勘探成果提出了进一步勘查的大比例尺工作预测靶区三处：乌栗山靶区、前冲靶区和桂花冲靶区。通过对以往狮子山矿田勘探方法技术手段的分析研究，结合本次综合物探勘查和新方法技术的应用研究，探讨了进行深部隐伏矿定位预测的方法技术及合理选择方法组合的原则，指出具有大探深、高分辨率的物探方法技术虽然很关键，同时也强调了进行综合勘探方法组合的必要性。更多还原

【Abstract】 The research content of dissertation mainly connects with the expert research item "The deepfine structure and mineralization research of large ore concentrated area" (NO. 1212010561607)that belong to "The ore exploration model and technical method for important ore belt in China"support by technique and international cooperation department of The Ministry of Land andResources P.R.C.Large ore concentrated area are important base of mineral resources output and it have quiteimportant meaning for national economy development. Many exploration case proved that therehave more potential for find new ore deposit and expand resource reserves in the depth andperiphery of old mine or old concentrated area. Strengthen research and explore assessment forsubstituted resources of ore concentrated area is a key approach to expand mineral resourcesreserve and it also have important meaning for decrease resources crisis of old mine.The focus of location and prediction research for substituted resources is how to seek lieconcealed ore and how to locate and forecast lie concealed ore. According analysis of internationalresearch development about concealed ore location prediction and the development progress ofconcealed ore since 1949, it indict that theory research about concealed ore in China is the basic ofsynthetically technique application for ore locate and predict. Nowadays, it in dire need ofintegrates with ore forming theory to strengthen the research of synthetically method optimizecombination.Though summarize and discuss concealed ore exploration and large scale ore location andprediction, the basic thought for concealed ore exploration was expatiated like follows: first ofall ,it should strengthen basically geological theory research and expand newly ore explorationthought, second insist use synthetically methods to explore ore and take full advantage of newapproach and new technique. A idiographic approach for large scale concealed ore located andpredicted was discussed and a suggestion that synthetically geophysical method should strengthenin middle scale (1:50000) and large scale (1:2000 to 1:10000) synthetically solid geologicalmapping.3-D solid geological model of Shizi mountain deposit in middle scale (1:50000) andDonggua mountain deposit in large scale (1:10000) was set up.According distributing of mine deposits, from west to east, there are five large mine depositin Tongling large ore concentrated area: Dongguan mountain deposit, Shizi mountain deposit,Xinqiao deposit,Fenghuang mountain deposit and Shatanjiao deposit. In these ore deposits,Shizimountain ore deposit is one of the deposits that be researced more advantaged in China presentlyand it is a ideal site for concealed ore location and predict research.Magma intrusion and ore deposit output mainly controlled by west-eastern basement faultand east-northern structure on base floor. In ore field and deposit scale, Tongling ore depositslocate in the structure which pattern named "row-line-cluster" in shallow crust belt and thisstructure style is the most important structure mechanism for fluid ore deposit forming. The bestCombine of different scale ore-controlling structure is main mechanism of this type ore depositforming. According to ore-controlling character, ore field structure can be divided into three types:first, "row-line-cluster" structure type in shallow belt, second, magma intrusion contact structuresystem in middle belt, three, "depression above swell" structure in deep belt. These three type beltdepth partly in 0-10km, 1-3km and more than 3km and composing ore field structure plumbdivided in space. In different ore field there have different combination of shallow, middle anddeep ore-controlling structure bundle, intact ore field structure vertical zoning was forming when these three belts completely output.The mineralization geological condition, cause of deposit formation about Tongling ore fieldwas analysesed and the relationship between ore-controlling structure (stratum, rock body andstructure) and concealed ore was confirmed. Though anatomize typical ore deposit such asDonggua mountain ore deposit and east Shizi mountain deposit and research mineralization modelwhich already be set up such as "multistory " and "multi-phase centralize on one body"mineralization patterns in Shizi mountain ore field and integrate with geophysical andgeochemical character , the method and symbol for ore exploration by geophysics andgeochemistry was summarizedThe main content of this research based on basically geology and geophysics andgeochemistry research and according with geophysical exploration result. Combine with researchresult in hand and use and introduce into new method and new instrument such as highresolution seismic and electromagnetism to research concealed ore, at the same time ,we pay moreattention to assess old resource and research location and predict of concealed ore in coveredarea.Though analyses deep seismic reflect profile that lasting 60 km and synthesis interpretexploration data, we find that Tongling ore deposits have double layer crust: crust thickness about31-33km and low crust thickness change mostly from 10km to 20km.Low crust in deposits northpresent multi-group stronger reflection layer which incline opposite and it is the directnessevidence of magma intrusion many times.A giant stronger reflection bundle was funded between up and lower crust (4-7s,TWT) in oredeposits, it confirmed that there exist large scale detachment belt. This belt create space conditionfor magma intrusion and magma room develop and then forming giant vault batholiths under oredeposits.Arc reflection caused by fold, break and intrusion structure was found in up crust in Tonglingore deposits and under complex arc reflection exist reflect transparency area, it confirmed shallowlayer exist giant magma room. The mathematic simulate result show magma intrusion movementthat begin from shallow giant magma room, in large scale, magma centralized in centre in deepcrust and expand to slide in shallow crust. This giant magma room basically controlled Yanshanperiod structure-magma-fluid metallogenetic action in Tongling ore deposits.Through research of high resolution seismic and tomography image on Shizi mountaindeposit, space layout shape of mineral layer and mineral structure of deposit(such as Wutonggroup tip) was find out primaryly, it have important directional meaning for deep ore exploration.We find up crust cover layer became non-coupling distortion and detachment belt between layerswas formed in the course of strong-weak layer distortion. We also discover detachment beltbetween layers is the key channel of low viscidity magma and mineralize gas and fluid.Magnetism and gravitational modules for concealed ore location and predict was set up basedon synthesis analysis and research about geophysics and geochemistry on Shizi mountain deposits.New high resolution gravitational, magnetism and electrical methods for deep and surroundconcealed ore exploration was exerted in predict area and according exploration result threepredict target area for next large scale exploration work was bring forward,there are Wulimountain target area,Qianchong target area and Guihuachong target area.According research on anciently exploration approach and method in Shizi mountain orefield and integrate with synthesis geophysics and new method application, a principle of method select and combination for deep concealed ore location and predict was discussed in thisdissertation, At last, it point out that high resolution and deep exploration method is important andsynthesis exploration methods combination also necessary.更多还原