西藏主要铁矿类型地质特征简介

西藏自治区地质工作开展得较晚,研究程度无论从深度或广度衡量,均远远落后于我国其它兄弟省、区。而铁矿地质工作就更晚了,自六十年代末至七十年代才逐步开展普查工作,至目前尚未勘探过一个矿区。为了让国内外读者了解“世界屋脊”上的铁矿概貌,作者根据各方面的地质成果,进行了初步的综合研究,现简要论述如下。     

中国铁矿资源现状与铁矿实物地质资料筛选

依据我国铁矿资源的类型、成矿区（带）和赋存特点,概述了当前我国铁资源的状况,提出了铁矿资源进行实物地质资料筛选要考虑的因素。结果表明：中国铁矿床类型齐全,以沉积-变质型为主,岩浆型、接触交代-热液型次之;我国铁矿床成矿条件复杂,大型、超大型矿床少,贫矿多、富矿少,且伴（共）生有益组分多,但呈现相对集中分布的特点,主要包括鞍山-本溪、攀西-滇中、冀东-密云、长江中下游、鄂西-湘西北、邯郸-邢台等6个成矿区（带）,新疆地区铁矿资源潜力巨大,是未来找矿的重点;铁矿资源实物地质资料筛选应考虑铁矿床成矿规模、成因类型、成矿时代、成矿区（带）等因素,兼顾具有典型、潜力巨大的铁矿床作为筛选对象。     

广东怀集东园铁矿地质特征及找矿方向

怀集地处大珠三角的西北门户,铁矿资源较为丰富.东园铁矿为 - 中小型矿床,赋存于六庵山岩枝(γ52(3))与F1逆冲断层夹持的东岗岭组大理岩内接触带上,为隐状的富磁铁矿体,成因类型属接触交代矽卡岩型磁铁矿床.通过研究,剖析了该矿床的地质特征及控矿因素,旨在寻找隐伏矿体,扩大找矿远景,这对矿山生产和远景规划,均具有重要的实际意义.     

内蒙古蛤蟆石铅银钼多金属矿矿床地质特征

内蒙古阿鲁科尔沁旗蛤蟆石铅银钼多金属矿地处内蒙古大兴安岭成矿带中南段,西拉木伦河断裂以北,工作和研究程度低,通过普-详查工作首次对该矿床有了较为正确、系统的认识。对矿区地质特征、矿体地质特征、矿石地质特征及成矿要素进行了初步分析总结,认为EW向断裂构造为成岩成矿断裂,矿体与EW向展布的沿断裂充填的晚侏罗世次流纹岩时空、成因关系密切,矿体赋存于次火山岩侵入接触构造-硅化蚀变带(次生石英岩化带)中,矿体呈脉状、透镜状EW向分布。通过分析认为矿床成因为次火山热液矿床,与次火山有关的硅化带、次生石英岩化带是该区寻找相似成因矿床的找矿标志。     

湖南圳口地区加里东期钨矿田成矿地质特征及找矿方向

湖南圳口地区钨矿田位于彭公庙花岗岩体南部,在矿田内已发现了圳口、杨梅坑、张家垄等大中型钨矿床。这些矿床中的矿脉均受NW-NWW向断裂的控制,成群成带密集分布,为同一时期不同地点形成的钨矿床,其中的张家垄钨矿床为首次在加里东期彭公庙岩体接触带发现和探明的具有工业意义的钨矿床。区内发育的彭公庙岩体为上述矿床的形成提供了较丰富的物质来源及热力资源。文章系统阐述了区域地质背景,在总结矿床地质特征、成矿规律及控矿因素的基础上,初步揭示了加里东期花岗岩与钨矿床的时空及成因关系,并提出了找矿标志及找矿方向。     

Application of Bi-dimensional empirical mode decomposition (BEMD) modeling for extracting gravity anomaly indicating the ore-controlling geological architectures and granites in the Gejiu tin-copper polymetallic ore field,southwestern China

The Gejiu tin-copper polymetallic ore field, located at the westernmost end of the Cathaysia Block in South China, is one of the largest tin polymetallic ore fields in the world. It is associated with magmatic-hydrothermal ore-forming processes triggered by deeply seated structures and concealed granites. The Bi-dimensional empirical mode decomposition (BEMD) was used to decompose gravity data covering an area including the Gejiu tin-copper polymetallic ore field in the west and the Bozhushan silver-lead-zinc polymetallic ore field in the east, which yielded three two-dimensional intrinsic mode function (BIMFs) images and one residue (Res(m, n)) image that depict four layers of geological architectures at different wavelengths within the study area. The high-pass filtered gravity component image (BIMF₁) is interpreted to depict the shallow geological architecture, which indicates that the skarn alteration and tin-copper mineralization with positive gravity anomalies are distributed around the granites characterized by negative gravity anomalies. The band-pass filtered gravity component image (BIMF₂) is interpreted to depict the middle-shallow geological architecture, which indicates that the outcropped granites in the western Gejiu ore field bounded by the Gejiu fault may extend to the eastern Gejiu ore field to form one integrated granitic complex in the subsurface. The other band-pass filtered gravity component image (BIMF₃) is interpreted to depict the middle-lower geological architecture, which indicates that there may be an EW-trending granite zone with negative gravity anomaly at middle-lower depth connecting the Gejiu tin-copper polymetallic field to the Bozhushan silver-lead-zinc polymetallic field, displaying the existence of an EW-trending regional polymetallic ore-forming zone within the study area. The low-pass filtered gravity component image (Res(m, n)) is interpreted to depict the lowest geological architecture within the study area, which reflects that there may be a pair of the NW-trending uplift zone of the mantle and/or the basement with positive gravity anomaly and the depression zone of the mantle and/or the basement with negative gravity anomaly. The Gejiu tin-copper polymetallic deposits and the related granites are located at the transitional zone between the uplift and depression, whereas the Bozhushan silver-lead-zinc polymetallic deposits and the related granites are situated within the depression zone, which implies that the diversity of the Late Yanshanian granites and the related polymetallic deposits in the study area may be controlled by the complexity of the crust-mantle interaction at depth.     

梅山铁矿矿浆成因的系统探讨

梅山铁矿在矿床地质特征、成矿流体来源、氧同位素的组成、实验岩石学资料以及稀土元素分布特征等方面，都充分体现了矿浆成因观点的正确性。特别是磁铁矿及其围岩中稀土元素的系统研究，为进一步探讨矿浆成因铁矿提供了新途径     

桂东大瑶山成矿带古木口金矿床地质特征及找矿方向

古木口金矿是在桂东大瑶山成矿带上发现的首例中型规模以上高品位金矿,其矿床类型属于中低温岩浆热液型。该金矿矿体呈似层状、脉状、透镜状产出,受断裂、成矿结构面及构造蚀变带控制,矿床在垂向和横向上具有石英脉型、破碎蚀变岩型及斑岩型分带特征。为及时总结矿区勘查新成果,推动该区找矿新突破,研究矿体与寒武系含碳细碎屑岩系、层间引张型走滑转换断裂、花岗闪长斑岩组合要素的空间关系,以及近矿围岩蚀变矿物组合标志、土壤化探异常等成矿综合信息;运用土壤地球化学测量及异常带槽探、钻探揭露等综合找矿方法,在总结分析了矿区地质-地球化学特征及矿化时空分布规律的基础上,提出了该区带的找矿方向。结果显示,该矿区深部及外围具有较好的找矿前景,特别是北西向断裂、引张型走滑转换断裂、伸展型脆-韧性剪切异常带利于寻找破碎带蚀变岩型富金矿,其构造相对封闭环境的深部是寻找斑岩型金矿的有利地段。     

东昆仑山西段铁矿成矿机制和找矿模型

在全面收集东昆仑西段地区3种主要铁矿矿床类型（迪木那里克、蟠龙峰、塔特拉克）资料的基础上,综合分析其成矿地质条件、物探等找矿信息,并对该区铁矿成矿机制进行了研究,建立其成矿模式,总结迪木那里克和蟠龙峰铁矿找矿模型。研究表明,沉积变质型铁矿主要分布于长沙沟蛇绿混杂岩和茫崖蛇绿混杂岩带内,成矿时代主要为古生代,含矿建造为复理石建造和大理岩建造。矽卡岩型铁矿主要分布在研究区中部呈北西-南东向展布的祁漫塔格蛇绿混杂岩带中,赋矿建造主要为古元古代白沙河岩组大理岩建造、蓟县系结晶灰岩-白云质灰岩-白云岩建造和上石炭统-下二叠统微晶灰岩-钙质白云岩-生物微晶灰岩建造,成矿时代为古生代和中生代;与成矿作用有关的侵入岩主要为印支期花岗闪长岩、二长花岗岩和燕山期的钾长花岗岩;矿体主要分布在受断层控制的侵入岩与碳酸盐岩接触带的矽卡岩中,矽卡岩以钙质矽卡岩为主。     

藏北羌塘中部难爬日铁矿地质特征及矿床成因

难爬日铁矿位于羌塘中央隆起区。对难爬日铁矿的地质特征、矿体及矿石特征进行初步调查,通过野外调研及室内岩相学与矿相学观察,将难爬日铁矿的形成划分为早期矽卡岩阶段、晚期矽卡岩阶段、氧化物阶段、石英—硫化物阶段及后期氧化作用阶段5个成矿阶段,同时对难爬日铁矿的围岩蚀变和矿化富集规律进行分析。根据矿体产出地质条件、矿石矿物组合及围岩蚀变特征,并结合前人资料认为,难爬日矿床属接触交代型铁矿床,晚三叠世中酸性侵入岩与碳酸盐岩接触部位为重点找矿地段。     

湖北大悟娘娘顶钨铍矿地质特征及找矿方向

湖北大悟娘娘顶钨铍矿区处于华北板块与扬子板块之间的桐柏-大别造山带中部,区内元古宙地层出露广泛,岩浆活动频繁,构造具有多期次性。矿区内钨铍矿床产于花岗岩体接触带上,与燕山晚期娘娘顶岩体、鸡公山岩体密切相关。本文在分析了娘娘顶钨铍矿成矿地质背景和矿床地质特征的基础上,进行了勘查地球化学研究,圈定了2处化探异常,指出本区内燕山晚期花岗岩与地层、岩体间接触带及构造破碎带部位为重点找矿地带及找矿方向。本次研究既填补了武当-桐柏-大别成矿带钨铍矿相关矿产研究方面的空白,又首次描述了研究区内铍矿床的地质特征,补充了国内研究相对很少的铍矿床方面的内容,同时为研究区乃至大别山地区下一步钨铍矿种的勘查工作提供了一定的理论依据和指导意义。     

Stochastic Distance Based Geological Boundary Modeling with Curvilinear Features

Obtaining accurate geological boundaries and assessing the uncertainty in these limits are critical for effective ore resource and reserve estimation. The uncertainty in the extent of an ore body can be the largest source of uncertainty in ore resource estimation when drilling is sparse. These limits are traditionally interpreted deterministically and it can be difficult to quantify uncertainty in the boundary and its impact on ore tonnage. The proposed methodology is to consider stochastic modeling of the ore boundary with a distance function recoding of the available data. This technique is modified to incorporate non-stationarities in the form of a locally varying anisotropy field used in kriging and sequential Gaussian simulation. Implementing locally varying anisotropy kriging retains the geologically realistic features of a deterministic model while allowing for a stochastic assessment of uncertainty. A case study of a gold deposit in Northern Canada is used to demonstrate the methodology. The proposed technique generates realistic, curvilinear geological boundary models and allows for an assessment of the uncertainty in the model.     

河南省卢氏县八宝山铜矿床地质特征及成因

河南省卢氏县八宝山岩体属晚侏罗世中酸性浅成小岩体。结合前人研究成果,通过研究该矿区地质特征和物化探成果,结合本次普查中对成矿理论的实地钻探工程验证,研究认为八宝山矿床类型为斑岩-矽卡岩型矿床,且矿床由内向外具有明显的高中低温分带性,矿床三种分带围绕岩体呈环状分布。成矿模式为以岩体中心相为中心至外侧边缘相,依次为斑岩型-矽卡岩型-热液型三条环带模式。研究区最新提交备案成果（普查）：铁矿石量2389.10万吨,硫铁矿石量334.00万吨,铜金属量108962,提交一中型铜矿床。通过研究该矿床成因及成矿模式,为研究区资源储量提升找到工作靶区,也为寻找相同类型矿床或者附近隐伏矿床提供借鉴依据。     

广东省阳山县石寨铅锌多金属矿地质特征

阳山县石寨矿区隶属南岭钨锡多金属成矿带,属矽卡岩型铅锌多金属矿,是武警黄金九支队首次针对此类型矿床进行勘查。矿区内花岗岩体广泛与石炭系地层接触,接触带长度延伸较长,具有较好的成矿条件。已发现的矽卡岩带,受接触带构造影响,在走向与倾向上整体呈"S"型舒缓波状,铅锌矿体主要赋存于矽卡岩带中。通过物化探基础性工作,并利用钻探及槽探工程进行查证,物化探异常与已发现矿脉吻合度较高,且深部呈现铅锌多金属元素富集增高的趋势,显示了较好的找矿前景。通过对区内多金属矿床地质特征、成矿规律分析与找矿前景分析总结,为在该区深部进一步开展找矿勘探,扩大其远景规模提供了明确方向和详实的地质资料。     

浙江诸暨上山坞地区地质地球化学特征及找矿远景研究

上山坞地区位于江绍拼接带的北东端,芙蓉山破火山构造东部。区内出露陈蔡群徐岸组变质岩、上侏罗统西山头组中一酸性火山碎屑岩．环状、放射状断裂发育,徐岸组与西山头组地层为断层接触,接触带两侧共圈定四个综合异常区,区内发现多条矿化带,其中上山坞村综合异常区是寻找铜矿床的良好靶区;王坞坑综合异常区是寻找锌、铅的良好靶区,经深部钻探王坞坑综合异常区已发现舍铅、锌矿段。     

Real-time Uncertain Geological Boundaries Updating for Improved Block Model Quality Control Based on Blast Hole Data: A Case Study for Golgohar Iron Ore Mine in Southeastern Iran

One main problem in the modeling of mineral deposits is to design a block model that divides the deposit into homogeneous subdomains. The spatial uncertainty in the geological boundaries becomes a critical factor prior to the modeling of the ore properties. For this reason, reducing the uncertainty of geological models leads to an improved mineral resource evaluation. This research work addresses the problem of updating the geological models by using actual online-sensor measurement data. A novel algorithm is provided, which integrates the discrete wavelet transform to the Ensemble Kalman Filter for assimilating online-sensor production data into geological models. The geological realizations in each time step are transformed to frequency coefficients and, after each assimilation step, the updated realizations are back-transformed to the original categorical distribution. Furthermore, a reconciliation process is performed to compare the online-sensor data derived from the production blocks and the updated realizations in each time step. The algorithm is illustrated through an application to the Golgohar iron deposit located in SW of Sirjan, Iran, and proves to reproduce the statistical parameters and connectivity values of the primary geological realizations.

     

牛苦头矿区隐伏矿床预测方法及其勘查成果

牛苦头隐伏大型铁多金属矿床的成因属于矽卡岩矿床。矿区出露地层为上石炭统四角羊沟组碳酸盐岩,岩浆岩为隐伏于矿区深部的印支期二长花岗岩,铁多金属矿体主要产于两者外接触带附近。矿区的勘查工作始于1969年,但主要工作一直针对近地表规模较小的零星铁多金属矿体开展,对矿区总体地质特征缺乏系统的认识,以致以往的勘查找矿工作始终进展不大。直到2006年,通过综合分析矿区内地质矿产和地球物理特征,根据矽卡岩型矿床成矿理论,以地球物理异常圈定等方法成功地进行了隐伏矿床预测,进而取得重大找矿突破。     

和静备战铁矿床地质特征及控矿因素分析

新疆和静县备战铁矿位于巩乃斯石炭纪裂谷带东端楔形尖灭部位,矿体受下石炭统大哈拉军山组灰岩与华力西中期石英二长斑岩体接触带的控制.矿区内存在一个从基性→酸性,从橄榄玄武岩→玄武岩→安山岩→英安岩→霏细岩(流纹岩)演化的火山熔岩系列,同时发育大量火山碎屑岩及火山碎屑沉积岩,构成大哈拉军山组主体地层,为备战铁矿成矿的最有利层位.矿区南北两侧均为近EW向断裂构造,具压扭性质,是一个长期活动的构造薄弱带,有利于火山活动及岩浆岩侵入.从矿床地质特征出发,概括了该矿床的基本控矿因素,为下一步该类型铁矿床找矿提供依据.     

基于多源数据约束的成矿动力学模拟——以宁芜盆地钟姑矿田典型矿床为例

数据驱动是大数据分析的特点之一。成矿过程的数值模拟即采用数据驱动方式,在基本的物理化学方程及地质模型基础上,通过定量的手段,模拟不同阶段、不同条件下成矿系统的演化过程,从而能够更深入、直观的讨论各种地质要素对成矿系统的影响,验证已有的成矿理论,获得新的认识。姑山铁矿床和杨庄铁矿床是宁芜火山岩盆地钟姑矿田内的典型矿床。前人研究显示,杨庄铁矿床为典型的充填-接触交代型热液矿床,而姑山铁矿床目前在成因上仍存在争议,存在岩浆成因和热液成因等多种观点。为了更好的对比和了解姑山铁矿床和杨庄铁矿床的成因及成矿过程,本文基于多源数据的综合解译剖面,采用力-热耦合数值模拟方法对与热液矿床密切相关的扩容空间的形成机制和特点开展研究。模拟结果显示,姑山铁矿床和杨庄铁矿床可能分属不同的成因类型;随着岩体的逐渐冷却,杨庄铁矿床内岩体和地层接触带会出现明显的扩容空间,可为成矿流体的汇聚及矿质的沉淀提供良好的条件,有利于热液矿床的形成;而姑山铁矿床内岩体和地层接触带只有局部区域出现扩容空间,同时体应变数值较小且形态变化大,并不利于大规模的流体汇聚及矿质的沉淀,姑山铁矿床可能主要为岩浆成因,并受少量热液的叠加改造。