Geochemical and metallogenic provinces: a discussion initiated by results from geochemical mapping across northern Fennoscandia

The concept of metallogenic province has won general acceptance in economic geology. It is agreed that metallogenic provinces offer good opportunities for exploration of new ore deposits. The concept of geochemical province is also established, but its exact meaning is disputable. In this paper, geochemical province is used as an abnormal spatial distribution of an element or element combination in a particular sample type as measured by a particular analytical technique. The practical consequences of this concept of geochemical provinces in mineral exploration seem not to have been fully utilized, although geochemical and metallogenic provinces could only be different manifestations of the same regional features. The location of geochemical provinces should be of greater importance in exploration than the location of metallogenic provinces, simply because a geochemical province can be identified early in an exploration program, while a metallogenic province cannot be defined until a number of ore discoveries has already been made. We have compared metallogenic provinces with geochemical provinces obtained by regional geochemical mapping in Fennoscandia (mainly data from the Nordkalott Project) and other places such as England, Wales, Germany and Alaska in order to study to what degree large-scale geochemical dispersion patterns can be associated with clusters of economically interesting mineral deposits.It is concluded that metallogenic provinces lie within or coincide with a number of geochemical provinces, some of which may have causal relationships with the ore deposits. It can be assumed that an enormous hierarchy of large and small geochemical provinces exist at the earth's surface. The main features of this system would be detectable by worldwide low-density geochemical mapping. Such mapping should be performed in order to shorten the time lapse between possible rises in the demand of certain raw materials and their supply. Worldwide geochemical mapping would also contribute to a better understanding of major geochemical processes of the Earth and provide baselines for environmental research.     

Deep Tectonic Processes and Superaccumulation of Metals Related to Granitoids in the Nanling Metallogenic Province, China

The Nanling region is an important nonferrous and rare metal metallogenic province in South China, in which most of the deposits are related to granitoids in genesis. It covers southern Hunan, southern Jiangxi, Guangxi, Guangdong and Fujian provinces, with a total area of about 550,000 km2. This metallogenic province is well known in the world for its rich tungsten and tin resources. In the past 40-odd years, a vast amount of mineral exploration activities and studies of the geology of mineral deposits have been carried out and great achievements obtained in the province. This paper is focused on a discussion about the deep tectonic processes in the orogenic belt during the Mesozoic and their contribution to the superaccumulation of metals. Tectonically, this metallogenic province is composed of three units: (1) the marginal continental orogenic belt in the Southeastern Coast fold system in the Yanshanian; (2) the intercontinental orogenic belt in the collision suture belt between the Yangtze and Cathaysian plates mainly in the Caledonian; and (3) the intracontinental orogenic belt induced by subduction of the ocean crust and delimination of the mantle lithosphere in the Yanshanian. It is suggested that superaccumulation of metals in this metallogenic province was caused by the existence of mantle rooted tectonics at the depth based on comprehensive studies of geophysical information of seismic, geothermal and magnetotelluric surveys in Nanling and its adjacent areas. The Xihuashan wolframite quartz vein deposit, the Shizhuyuan W, Sn, Mo, Bi greisen-skarn deposit and the Dachang tin-polymetallic deposit are three typical examples of the deep tectonic processes. However, this kind of deep tectonic processes only act as the "engine" of the superaccumulation of metals, which means that they should have to correspond with the super-crust ore-controlling pattern of "lines-rows-clusters" (L-R-C). This recognization is expected to play an important role in assessment of mineral resources in this province.     

甘肃省成矿区(带)研究

成矿区（带）是区域成矿学的核心内容,成矿区（带）的划分和研究是成矿规律认识的深化和科学表达,同时是具有矿产资源潜力的成矿单元,是服务于勘查决策的主要载体。文章根据全国成矿区（带）划分意见,对甘肃涉及的4个成矿域、8个成矿省及12个Ⅲ级成矿区带进行分析和研究,依据省内区域矿产空间分布的集中性和区域成矿作用的统一性原则,重点讨论矿床所处的大地构造环境、成矿作用与区域地质演化过程、容矿围岩时空分布一致性或相似性;参考区域地球化学场、地球物理场特征,划分Ⅳ级成矿区（带）26个,Ⅴ级成矿区（带）94个。明确各级成矿区带地质意义及显著特征。文章指出本次对甘肃省成矿区带的划分具有探索性,随着认识不断深化,成矿区带的研究和厘定将更加科学。     

Thematic integration of spatial data sets to delineate favourable zones for uranium exploration in Gangpur basin and parts of Kunjar and Darjing basins,Odisha

Surface exploration techniques have been key contributors in discovering mineral deposits over the past three decades. However, in the last decade there has been a growing emphasis on integrating remote sensing, geological, geophysical and geochemical exploration techniques to compliment them in identifying concealed deposits. Successful integrated exploration requires putting mappable petrophysical property contrasts in terms of geological and geochemical process that could be associated with different mineralisation environment. The Precambrian Gangpur basin comprising volcanic free sedimentary sequence is considered as a potential geological setting for hosting uranium mineralisation. The Gangpur basin with metasediments of low to medium metamorphic grade classified as the Gangpur Group are known for hosting manganese, limestone and lead-zinc deposits. Uranium mineralization is reported in limonitic carbonaceous phyllite and sheared quartzite of Kumarmunda Formation at Jhamankele-Bhalulata areas. Several uranium anomalies have been associated with gossan at Kaedarpani, Jamdra and in ferruginised laterite at Badekachar, Jarmal, Jhagarpur, Kadorpani, Karamabahal, Tetelkela & Kumtinunda. In the present study geological, geophysical and remote sensing data sets are processed and integrated with other available data to delineate target zones for uranium exploration. Even though direct detection of uranium mineralisation remains unresolved in exploration strategy, instead it is becoming increasingly instructive to focus on mapping suitable depositional environments. The enhanced satellite imagery is interpreted in terms of thematic layers viz. trend lines, lineaments, faults and geological contacts. The aeromagnetic data is processed and interpreted thematic layers of magnetic breaks and linears from total magnetic intensity (TMI), the reduced to pole (RTP), tilt derivative and amplitude of analytical signal grid images. The radiometric data is processed based on their broad lithology and radio-elemental distribution maps viz. count maps, ratio maps, ternary (%K-eTh-eU) and eU/K ? eU/eTh ? eU images are generated to aid in mapping uranium favourability zones. The favourability image zones with high eU/K, eU/eTh and eU counts zones are classified into class based on statistics and anomalous high zones are picked up as uranium favourable locales. The thematic layers of geological contacts, lineaments and faults interpreted from satellite imagery, magnetic linears interpreted from aeromagnetic data and uranium favourability zone extracted from Airborne Gamma Ray Spectrometric (AGRS) data are overlaid. Based on spatial association of favourable features few locals are delineated for uranium exploration.     

矿产勘查的双控论与合理域模型

金属成矿省等级体制成矿研究保证程度与技术－经济条件研究保证程度双控制的和对其保证程度相对优选的合理区域,是深化认识矿产勘查－开发客观规律和合理进行评价的新发展,也是把以往仅按在一定地质构造背景基础上,研究不同类型矿床特征及其勘查类型的传统方法。变革为按“景、场、相、床”4个等级体制成矿序次及其随成矿史演化进程的耦合程度,以及有机地结合经济－技术条件进行勘查评价的新方法。重点阐述了等级体制成矿概念的形成、意义和研究内容,提出了地质、技术经济和合理投资的矿产勘查评价三原则,建立了以保证等级体制成矿研究程度和技术－经济条件研究程度双因素控制,以及研究程度相对合理优选区域的矿产勘查模型。     

东帝汶国金属矿产资源潜力与矿业投资环境

东帝汶国的成矿地质条件较优越,矿产资源较丰富。铬铁矿化在马纳图托省、马努法伊省和包考省有明显的找矿信息,成矿环境受环太平洋成矿带超镁铁质岩带控制。其中位于马纳托图省HiliManu地区的蛇纹石化超基性岩中呈豆荚状产出铬铁矿,Cr2O3含量在36％～51％之间,显示出较好的资源潜力。锰矿化主要分布于包考省、维克克省和马纳图托省,为海相层控型,其中位于马纳托图省Vemasse地区的锰矿床规模较大,品位较高,具有成为中-大型锰矿床的潜力。铜矿化出露于包考省、维克克省、科瓦利马省、马努法伊省、马纳图托省和劳滕省,矿化作用与蛇绿岩套有关,其中位于维克克省Ossu地区的蛇纹岩体,存在与蛇纹石化基性-超基性岩石组合有关的铜／金／银矿化露头,暗示其下可能隐伏着更大的硫化物矿化体。金矿化既有热液脉型,又有浅成低温热液蚀变浸染型,更有河流砂矿型,分布范围广,品位中等到较富,其中马努法伊省Turiscai地区Sue河、Laclo河及Cler河沿岸砂砾层中存在找寻砂金矿的前景,河流上游存在原生金矿的可能。综上所述,东帝汶国具有明显的找矿前景、矿产资源开发潜力和较好的矿业投资环境,建议加大工作力度,把握机会,适时介入。     

山东省重点地区矿产勘查开采遥感动态监测探析

为打击各类违法采矿行为,自2007年起山东省在全省基岩裸露区开展了多轮次矿产勘查开采遥感动态监测,及时发现了各类违法勘查开采矿产资源行为,为监测区矿产资源监管提供了执法依据。结合山东省矿产勘查开采遥感动态监测工作现状,探讨了矿产勘查开采遥感动态监测相关工作内容及要求。     

甘肃北山地区区域成矿规律探讨

甘肃北山地区是古亚洲成矿域重要的组成部分,包含了两个（即准噶尔成矿省、塔里木成矿省）金、铜、铅、锌、钨、钼、铷、铁等重要成矿省,目前已发现重要矿产地289余处,成矿时段以华力西期为主。本文通过对甘肃北山地区成矿地质背景和成矿在时空上的联系性、矿产预测类型、成矿作用演化的综合研究,简要介绍了Ⅳ级成矿亚带地质矿产特征;重点讨论了区域成矿控制因素;并归纳总结了矿产预测类型,概述了区域成矿的时空演化规律。以期为矿产勘查和地质大调查工作部署提供了新的思路和依据。     

超大型矿床成矿背景-过程-勘查三位一体的找矿理念

超大型矿床是某一(或某些)矿种资源的巨大储库.据统计,全球矿产资源70％～85％的勘探储量集中分布于占全球矿床数10％的超大型矿床.由此可见发现超大型矿床对一个国家经济与社会发展的极端重要性.超大型矿床成矿背景是其形成的基础,成矿过程是其成矿的关键,勘查评价是其发现的根本途径.文章试图从成矿背景、成矿过程与勘查评价相互...     

Geochemical and electron paramagnetic characteristics of quartz from a multi-stage vein environment, Cowarra gold deposit, New South Wales

The characterisation of quartz using trace element geochemistry and electron paramagnetic resonance measurements has been tested for different generations of quartz veining in the multi-stage hydrothermal vein system at Cowarra. Quartz closely associated with gold mineralisation can be distinguished from earlier and later quartz generations in the mineralised environment, and both types can be distinguished from regional, barren quartz veins. These separate stages of quartz veins are also recognised from their fluid inclusion characteristics. Geochemical differences in the quartz partly reflect the presence of minor mineral inclusions, particularly sulfides and arsenopyrite.The study highlights the importance of understanding the paragenetic sequence of quartz vein development in a mineralised environment and the need for careful, thorough sampling before attempting geochemical and EPR characterisation of quartz as an exploration technique.     

黑龙江省滨东地区Cu-Pb-Zn-W-As-Sb-Bi-Au-Ag地球化学块体矿产资源潜力预测

黑龙江省滨东地区是著名的铜铅锌钼成矿带.以金属活动态测量法进行的超低密度地球化学调查圈定的滨东地球化学块体为基础,运用成矿可利用金属量定量评价模型与方法对该块体的Au、Ag、Pb、W等矿产资源潜力进行了预测,预测结果远远大于该区已发现矿床的总储量,说明预测结果是合理的.预测结果对进一步开展矿产勘查工作具有参考和指导作用.     

Predictive mineral discovery in the eastern Yilgarn Craton,Western Australia: An example of district scale targeting of an orogenic gold mineral system

The eastern Yilgarn Craton (EYC) is one of the world's premier gold provinces subject to over a century of mineral exploration. Prolonged interest in the terrane has led to the assembly of multiple world-class data sets suitable for testing district scale targeting methodologies. District scale targeting is concerned with identifying a mineral camp ∼60 km × 60 km in size within a prospective region or province ∼1000 km × 1000 km in size. Exploration at the district scale necessitates the development of predictive exploration models, which can be applied to large regions. Recent advances in the study of the geodynamic evolution and 3D architecture of the EYC, together with an understanding of their interrelationship with the orogenic gold mineral system, has resulted in identification of critical mineralisation processes responsible for the region's rich gold endowment. Here we describe and map these critical processes, using them as a basis for district scale targeting. We relate gold mineralisation to three temporally constrained geodynamic periods, integrated with regional hydrothermal alteration. Unlike many targeting methodologies, this methodology does not incorporate the location of known gold deposits in the analysis, yet it predicted 75% of known gold mineralisation in 5% of the area. The methodology allows critical mineralisation processes to be identified and mapped through time and space. These critical processes are mostly generic and can be applied to other granite–greenstone orogenic gold regions, such as the Abitibi in Canada. An important outcome of this work for the EYC is the identification of a number of new target areas, not known currently for significant gold mineralisation, in what is otherwise thought to represent a mature terrane for gold exploration.     

墨西哥地质、矿产及矿业经济概况

墨西哥合众国矿产资源丰富,经济环境相对稳定,矿业是其经济支柱。墨西哥地质格局由古老的基底残片与古洋壳不断增生拼合而成。活跃的地质过程造就了分布广泛、数量众多、类型各异的矿产,按成因来看这要有低温热液型、矽卡岩型、MVT(密西西比河谷型)、VMS(火山岩块状硫化物型)、SEDEX(沉积喷流型)、IOCG(铁氧化物铜金矿)等类型。本文介绍了墨西哥的地质概况、六个主要的成矿期、各矿种分布特征;另外,墨西哥政府对矿产的勘查、开发等有相对开放、优惠的政策;在墨西哥未来经济中,矿业仍将扮演重要角色。     

广东河源七目嶂地区内生金属矿产成矿预测

广东河源七目嶂地区内生金属矿产成矿预测区位于华南成矿省梅县-惠阳成矿区内,属A类成矿预测区,已发现中小型矿床12处,成矿地质背景优越,可与已知矿区类比,找矿标志明显,矿产资源潜力较大,利用计算机技术在G IS平台上对化探成果进行整理和剖析,结合成矿地质背景,圈定了3个进一步勘查靶区。     

全国区域化探数据库

全国区域化探数据库首次汇集了全国28个省（自治区、直辖市）的1∶20万和1∶50万区域化探39种元素和氧化物的测试数据,共计数据点142万个,近5 540万个数据,涉及1∶20万图幅1 299个,1∶50万图幅18个,在国内第一次建立了地球化学海量数据库。全国矿产资源潜力评价项目对数据库进行了更新,使全国区域化探数据库汇集数据总量达147万余条记录,数据达6 321万。在此基础上,编制了4万多张各类地球化学系列图件,并建立了空间数据库,为地球化学研究和矿产资源预测相关专业提供了丰富的地球化学信息。该项成果的取得为在全国范围内研究区域地球化学分布、生态环境、基础地质和找矿远景规划提供了最基础的资料。     

贵州矿产资源与人的生产生活

贵州矿产资源丰富、分布广泛、门类齐全、矿种众多,是全国重要的矿产资源大省之一,通过了解贵州省的矿产资源分布概况、开发现状及其与人们生产、生活的密切联系,可为“富民兴黔”的经济战略目标提供参考。     

论发展吉林农业地质的前景

吉林是全国产粮省之一,又有较好的基础地质工作,有较多的非金属矿产资源,因此具有广阔的农业背景地质、非传统性矿产肥料,土壤改良资源和矿物饲料资源。     

青海省木里煤田预测区圈定及资源潜力评价

木里煤田是祁连山赋煤带的主要煤炭资源聚集区,其资源储量占全省总探明资源储量的70%以上。本次研究是通过综合运用地质构造、物探成果、聚煤规律及生产勘探成果资料,在木里煤田聚乎更、弧山、外力哈达、热水及默勒地区共圈定了40个煤炭资源有利聚集区。预测区面积达600.85km2,合计预测资源量1 054 561万t,其中,优（A）等资源量70 891万t,主要分布在聚乎更-哆嗦公马矿区的东西延伸部位,良（B）等资源量420 016万t,主要分布在已知矿区的外围和深部,差（C）等资源量563 655万t,主要分布在预测依据不太充分的区域。通过对木里煤田煤炭资源潜力的深入研究,对煤田煤炭资源的开发利用前景作出初步了评估,为煤炭资源勘查近期及中长期部署提供了依据,同时对全省煤炭资源潜力评价具有重要的指导意义。     

岩浆热液型银矿床、银矿省及形成的控制因素

岩浆热液型银矿床主要指与岩浆热液作用相关的独立银矿床和共生银矿床(Ag平均品位一般大于100g/t),它是银最重要的来源。本文对全球80多个典型的大型-超大型岩浆热液型银矿床进行了梳理和总结,将其主要分为浅成低温热液型(低硫型、中硫型和高硫型)、矽卡岩型、斑岩型和五元素型四种类型,其中浅成低温热液型占主导,斑岩型和矽卡型数量较少。全球大型-超大型的岩浆热液型银矿床主要分布在东太平洋俯冲带和中亚造山带东段,这些银矿床均位于陆壳基底之上。按照发育地区不同可分为六大银成矿省,即中国兴蒙银成矿省、美国西部盆岭银成矿省、墨西哥西北银成矿省、秘鲁中部银多金属成矿省、玻利维亚银锡成矿省和俄罗斯远东银锡成矿省。成矿时代主要集中在中、新生代。这些银成矿省与大规模酸性-中酸性岩浆活动密切相关,包括发育大量酸性熔结凝灰岩的长英质大火成岩省,或者富锡流纹岩、黄玉流纹岩和石英斑岩等高演化岩浆岩。这些大规模岩浆热液银成矿作用通常与区域大地构造背景转换相关,比如从挤压到伸展或者伸展到挤压。相对富银的含水大陆下地壳源区、大规模高分异的岩浆作用、银对熔体中共存硫化物和磁铁矿相对弱的相容性、高盐度的流体、成矿流体集中运移的通道和高效的沉淀机制是银大规模成矿的有利控制因素。银矿床的研究工作相对于铜、金矿床远远落后,银成矿省和酸性大火成岩省的内在联系、控制斑岩钼-银/锡-银两种银成矿系统的机制、岩浆演化对银成矿的控制、银矿潜力区的勘查找矿等关键问题仍亟待解决。