扎兰屯铀成矿远景带南段铀成矿特征及预测评价

研究区位于扎兰屯火山岩型铀成矿远景带南段,燕山期强烈的构造-岩浆活动造就了区内绝大多数铀成矿作用。通过综合整理前人资料及区内开展的铀矿资源调查评价工作,从铀矿时空分布特征、铀矿化特征对区内铀矿地质特征进行总结分析;将区内火山岩型铀矿划分为潜火山亚类、蚀变裂隙带亚类和层间破碎带亚类3种类型;区内铀成矿受地层岩性、潜火山岩、构造、热液蚀变复合控制,其中潜火山岩和构造起主导性作用;初步预测出4处铀成矿远景区,为下一步找矿工作指明方向和思路,以实现铀资源的扩大预期。     

陕西宁强土地垭铜金多金属矿地球化学特征及找矿标志

工作区位于陕西省宁强县北西太阳岭至清河一带,通过土壤测量,岩石、地化剖面等工作手段,大致了解了区内的地层、构造、矿化蚀变特征。基本查明了区内地球化学异常分布情况,引起原生晕异常的构造地质体、石英脉体的分布范围及特征。本次工作共圈定出综合异常3处,圈出2个Au原生晕异常带,Au异常分布比较零散,主要集中在韧性剪切带构造断裂附近,Au异常受构造控制,主要异常以面积大强度低或面积小强度高为特征。同时加强控矿地质条件和赋矿规律的研究,开展成矿预测,总结出区内找矿标志主要有韧性剪切带内的褐铁矿化带、硅化带,石英脉以及化探Au异常。为以后在该区更深入地开展找矿和评价工作奠定了基础。     

安徽枞阳城山地区地面伽玛能谱异常特征及成因分析

枞阳县城山地区位于长江中下游地区庐江-枞阳中生代火山岩盆地东南缘黄梅尖-大龙山铀矿田中部,区内碱性花岗岩发育,属于江北A型花岗岩带的重要组成部分,区域铀成矿条件优越。为研究区内与A型花岗岩有关的铀异常特征,本次工作采用地面伽玛能谱测量对该区进行初步分析研究,后期在重点地段进行地质-能谱-岩石化探综合剖面测量,进一步研究区内铀矿化成因及控矿因素。通过研究发现,区内铀矿化主要分布于能谱U异常高值区,受岩体、地层、构造等联合控制,初步圈定两处找矿有利地段,为后期铀矿找矿提供指导。     

青海东昆仑哈西哇金多金属矿地质特征及找矿前景

研究区内广布的富金元古宇地层是金矿集中区形成的基础,多期次的强烈岩浆活动为金矿集中区的形成提供了极为丰富的成矿流体和矿质来源,脆韧性剪切带为矿液流通和汇聚提供了有利空间。在区内的脆韧性剪切带中分布有Ⅰ矿带和Ⅱ矿带,带内发育硅化、绢云母化、黄铁矿化、绿泥石化、碳酸盐化、纤闪石化、高岭土化蚀变,金多金属矿化主要与硅化、绢云母化、绿泥石化、黄铁矿化关系密切。目前已提交金资源量约8.94t,银金属量约247.02t,铅金属量约6.45万t,锌金属量约5.23万t。综合分析该区地质矿化特征和控矿因素认为,研究区成矿条件优越,找矿潜力巨大,通过开展进一步勘查工作有望达到大型金多金属矿床规模。     

青海西部祁漫塔格成矿带找矿新进展及其意义

青海省祁漫塔格成矿带位于东昆仑造山带北西段,带内以往开展了以铁为主的找矿工作,发现一批矽卡岩型中型矿床。近年来带内找矿取得了重大突破:①发现一种新类型矿床——"虎头崖"式层控型大型多金属矿床;②低缓磁异常区多金属和铁矿找矿效果显著,发现四角羊-牛苦头大型多金属矿床,野马泉矿区多金属矿规模达到中型,尕林格矿区发现深部厚大的铁矿体。在系统地综合总结这些成果的基础上,探讨了找矿新进展的意义,划分了3处成矿远景区,并初步讨论了各成矿远景区内进一步找矿的方向。     

青海祁漫塔格卡尔却卡铜多金属矿区矿床地质特征及控矿因素

卡尔却卡地区是青海省重要的铁、铜、铅、锌、金多金属矿集区,具有特征明显的构造-岩浆岩带。在分析区内地层、构造、岩浆岩及接触带等控矿因素与成矿的关系的基础上,建立了找矿标志;根据区内的成矿特征,初步认为卡尔却卡多金属矿床为斑岩型矿床成矿系列,有斑岩型、夕卡岩型和蚀变岩型3种成因类型,形成斑岩-夕卡岩-热液成矿系统,成矿作用均与中-晚三叠世底侵事件有关。     

青海东昆仑那更康切尔银矿地质特征及找矿远景浅析

青海省那更康切尔银矿是近年来在青海东昆仑成矿带首次发现的独立中低温构造热液型银矿床,运用地、物、化综合手段评价,发现了3条银矿化带、7条银矿体。通过对那更康切尔银矿地质特征、控矿因素及找矿标志进行综合分析和研究,认为该矿床具大型银矿的成矿潜力,以指导区内该类矿床找矿方向。     

甘肃舟曲县老沟金矿地质特征及矿床成因

甘肃省舟曲县老沟位于扬子板块北西段、中朝板块南侧、松潘-甘孜褶皱带以东的三角区内,属于秦岭褶皱带西段南亚带的白龙江复背斜。地层、构造及物、化环境,对金成矿十分有利;综合区内及邻区地质特征,初步认为老沟金矿是受地层、构造和岩脉复合控制的中低温热液型矿床。     

赣南河草坑铀矿田控矿因素及找矿潜力分析

文章在介绍河草坑铀矿田成矿地质背景的基础上,结合近些年开展的铀资源调查评价工作,对控矿因素进行了分析,并认为区内铀矿化主要受断裂构造、岩体、火山作用和蚀变带控制,区内铀矿化是构造-岩浆活动和热液蚀变共同作用的产物;提出了矿田南东部的龙骨千—仙坑地段、会昌红盆东缘深部和火山口及近外围铀成矿地质条件有利,找矿潜力大。     

青海省同德县加吾金多金属矿区微量元素在地质体中的分布特征

青海省同德县加吾矿区处在东昆仑-西秦岭衔接部位的青海南山冒地槽带。区内地层以中三叠统隆务河群为主,构造以NNW向压扭性断裂为主,除曲如沟花岗闪长岩体外,其余以花岗斑岩脉产出。区内除Cr、Mo外,大部分元素较为富集,其中Au、As、Sb、Bi、Ag富集程度较高,尤其在破碎带、褐铁矿化石英脉和花岗斑岩脉中,Au、As、Sb、Bi、Pb等元素的含量比其余几种岩性高1-3个数量级。通过因子分析和建立地球化学模式图,客观的反映了区内各地质体中微量元素的分布规律。     

贵州省晴隆县金矿成矿特征及找矿方向

根据区域地质调查和几个矿床、矿点深入研究,初步总结了晴隆县碧痕营背斜金矿成矿特征。金矿主要分布在背斜南东翼南段老万场、紫马一带,有红土型、卡林型两种金矿类型,以前者为主。老万场、王家湾一带红土型金矿从“大厂层”中风化剥蚀堆积形成;紫马、羊昌一带红土型金矿从上二叠系龙潭组合金层风化剥蚀堆积形成。根据其成矿特征,提出今后找矿方向。     

Soil-geochemistry,radiometric and soil gas helium studies in the uranium mineralized zone of Tumallapalle,Cuddapah Basin,Andhra Pradesh

A geochemical soil sampling survey undertaken at Tumallpalle uranium mineralized zone Cuddapah district, has confirmed the presence of uranium anomalies in soils. Bulk soil samples were collected at every 20 m along the traverse from approximately 30 cm below the surface and were assayed for uranium by x-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). The uranium anomalies detected by the insitu radiometric survey show a correlation with the helium highs. The soil gas helium studies have aided in delineating the subsurface extension of the deposit. This study endeavors for an integration of different techniques in a known area which could probably aid in delineating uranium zones for optimal exploitation in the future exploration programmes.     

Aeromagnetic data analysis to enhance the demonstration of the subsurface mineralized zone occurrences, As-Safra prospect area, Saudi Arabia

The aeromagnetic survey was conducted by the French organization, BRGM in 1966, where As-Safra prospect area at the east of Al-Madinah city was included. The aeromagnetic data were then interpreted for potential occurrences of mineralization zones along with their extensions. Spectral analysis, using Filon Fourier transform, was implemented to extract the residual anomalies that can be attributed to mineralization zones. In this study, analytic signal, normalized standard deviation (NSTD), and 3D Euler deconvolution filters were used to enhance the demonstration of subsurface mineralized zones occurrences. Analytic signal and NSTD filters showed that the studied area is dominated by three main trends controlling the occurrences of mineralized zones, NNW-SSE, N-S, and E-W to ENE-WSW. On the other hand, 3D Euler deconvolution filter showed that the dominant structures are mostly the magnetic contacts, and their depths vary between 118 and 355?m.     

青海格尔木小红山北部地区地球化学特征及找矿前景分析

小红山北部地区位于东昆仑成矿带中部,主体属雪山峰-布尔汉布达华力西-印支期钴、金、铜、玉石（稀有、稀土）成矿带,成矿地质条件优越.水系沉积物及土壤地球化学测量发现金异常强度较高.金矿（化）体主要产于奥陶-志留纪纳赤台群,有碳酸盐岩组合、变碎屑岩组合及中酸性火山岩,研究区内水系沉积物Hs65、Hs93异常三级分带明显,异常强度高.通过1：1万土壤测量,土壤异常Au、Cu、As、Sb等元素异常强度较高,异常曲线基本重合,经地表槽探工程验证发现并控制金矿体1条,矿化体6条.通过对小红山北部地区成矿地质条件及地球化学综合分析,对比大灶火金矿点,认为小红山北部地区通过进一步勘查工作有望找到金矿床,具有较大的找矿潜力.     

吉林省辽源市弯月金矿成矿地质特征及矿床成因

弯月金矿床是我队在吉林省东部地区发现有金矿化集中区之一,通过地表工程的深部稀疏钻孔控制,目前为一小型金矿床,普查结果表明,矿化系统有一定延深。本文对金矿床地质特征及矿床成因分析,认为构造、岩浆活动在成矿过程中起着重要作用,对吉林省东部金矿找矿有着指导作用,明确了本区深部找矿方向。     

吉南玄武岩覆盖区水化学异常查证──以两处金矿化的发现为例

本文通过实例,介绍了吉南玄武岩覆盖区水化学异常查证的化探工作方法。综合研究已有地质条件,认为吉南沿江村、马鹿沟水化学异常地区成矿地质条件有利。结合微景观特点,在沿江异常区2km²范围内应用汞气测量圈出区内断裂构造带展布方向。岩石剖面、土壤测量显示出构造经历过热液矿化活动,矿化体埋藏较深。根据土壤测量结果优选出验证靶区。钻探验证结果在地表620m以下发现了近30m厚的Au矿化体,Au含量最高1.5g/t.马鹿沟水化学异常区使用水系沉积物测量进行异常追踪,迅速缩小了找矿“靶区”.使用重矿物测量在“靶区”内进一步追踪发现了Au矿化源。在此基础上经大比例尺土壤测量辅以岩石剖面测量,圈出了一个有望找到火山岩型浅成热液金矿床的成矿远景区。     

内蒙古老国营子金铜矿床地质-地球物理勘查与研究

内蒙古老国营子金铜矿床是近年来利用地质与地球物理相互结合手段新发现的一个矿床。本次研究利用基于电磁原理的地球物理手段进行了找矿测试,结果表明:甚低频(VLF)地球物理扫面发现了近EW向和NW向的高阻带,分别对应了两条相应的矿化蚀变带。音频大地电磁法(EH4)测深影像显示矿化蚀变带表现为高阻异常带,与VLF的测量结果相一致。激电(IP)中梯测量显示矿化蚀变带具有高阻、高充电率和高金属因子异常特征。结合具体的地质特征,在老国营子金铜矿区综合运用这三种地球物理方法,取得了较好的找矿效果。     

吉林省通化县迎门岔一带白垩系下统火山碎屑岩稀有稀土矿找矿前景浅析

通化县迎门岔一带1∶20万水系沉积物测量,圈定出“通通-84-HS-10”号异常,异常区内出露的岩性主要为白垩系下统林子头组灰绿色、紫色流纹质凝灰岩、角砾凝灰岩、流纹质晶屑岩屑凝灰岩、灰紫色流纹岩、安山岩等火山碎屑岩。在1∶20万异常区内开展了1∶5万水系沉积物测量工作,圈出重点找矿前景区,并在该区内开展1∶1万土壤测量、高精磁测等工作,通过槽探工程验证,发现含铌钽矿化蚀变带,显示出该地区具有较好的稀有稀土矿找矿前景。     

甘肃省二只哈拉地区地球化学勘查实例分析

分析二只哈拉地区地球化学勘查资料认为,在以二只哈拉为代表的祁连山高寒地区进行1∶5万水系沉积物测量,样品粒度取-40目,可获得较好成果。在海拔3 000 m以上地段,采用1∶2.5万沟系次生土壤样测量,粒度取-40目上,欠合理性。采集小于0.5 cm的岩块,岩屑混合物测量,按原生晕的方法分析样品,能清晰圈定异常。各类化探异常成果预示了二只哈拉粱一带存在金矿（化）体,1∶1万岩屑异常基本圈定了矿化体范围。     

Geochemical soil sampling for deeply-buried mineralized breccia pipes,northwestern Arizona

Thousands of solution-collapse breccia pipes crop out in the canyons and on the plateaus of northwestern Arizona; some host high-grade uranium deposits. The mineralized pipes are enriched in Ag, As, Ba, Co, Cu, Mo, Ni, Pb, Sb, Se, V and Zn. These breccia pipes formed as sedimentary strata collapsed into solution caverns within the underlying Mississippian Redwall Limestone. A typical pipe is approximately 100 m (300 ft) in diameter and extends upward from the Redwall Limestone as much as 1000 m (3000 ft).Unmineralized gypsum and limestone collapses rooted in the Lower Permian Kaibab Limestone or Toroweap Formation also occur throughout this area. Hence, development of geochemical tools that can distinguish these unmineralized collapse structures, as well as unmineralized breccia pipes, from mineralized breccia pipes could significantly reduce drilling costs for these orebodies commonly buried 300–360 m (1000–1200 ft) below the plateau surface.Design and interpretation of soil sampling surveys over breccia pipes are plagued with several complications. (1) The plateau-capping Kaibab Limestone and Moenkopi Formation are made up of diverse lithologies. Thus, because different breccia pipes are capped by different lithologies, each pipe needs to be treated as a separate geochemical survey with its own background samples. (2) Ascertaining true background is difficult because of uncertainties in locations of poorly-exposed collapse cones and ring fracture zones that surround the pipes.Soil geochemical surveys were completed on 50 collapse structures, three of which are known mineralized breccia pipes. Each collapse structure was treated as an independent geochemical survey. Geochemical data from each collapse feature were plotted on single-element geochemical maps and processed by multivariate factor analysis. To contrast the results between geochemical surveys (collapse structures), a means of quantifying the anomalousness of elements at each site was developed. This degree of anomalousness, named the “correlation value”, was used to rank collapse features by their potential to overlie a deeply-buried mineralized breccia pipe.Soil geochemical results from the three mineralized breccia pipes (the only three of the 50 that had previously been drilled) show that: (1) Soils above the SBF pipe contain significant enrichment of Ag, Al, As, Ba, Ga, K, La, Mo, Nd, Ni, Pb, Sc, Th, U and Zn, and depletion in Ca, Mg and Sr, in contrast to soils outside the topographic and structural rim; (2) Soils over the inner treeless zone of the Canyon pipe show Mo and Pb enrichment anf As and Ga depletion, in contrast to soils from the surrounding forest; and (3) The soil survey of the Mohawk Canyon pipe was a failure because of the rocky terrane and lack of a B soil horizon, or because the pipe plunges. At least 11 of the 47 other collapse structures studied contain anomalous soil enrichments similar to the SBF uranium ore-bearing pipe, and thus have good potential as exploration targets for uranium. One of these 11, #1102, does contain surface mineralized rock. These surveys suggest that soil geochemical sampling is a useful tool for the recognition of many collapse structures with underlying ore-bearing breccia pipes.