Geophysical-Geological Interpretation and Deep-Seated Gold Deposit Prospecting in Sanshandong-Jiaojia Area, Eastern Shandong Province, China

Integrated gravitational, electrical-magnetic surveys and data processing carried out in the Sanshandao-Jiaojia area, Eastern Shandong Province, northeast China, aim to illuminate the geological characteristics of this shallow-covered area and delineate deep-seated gold prospecting targets. In this region, altogether 12 faults exert critical control on distribution of three types of Early Precambrian metamorphic rock series, i.e. those in the metamorphic rock area, in the granitic rock area underlying the metamorphic rock, and in the remnant metamorphic rock area in granites, respectively. Additionally, the faults have major effects on distribution of four Mesozoic Linglong rock bodies of granite, i.e. the Cangshang, Liangguo, Zhuqiao-Miaojia and Jincheng granites. The Sanshandao and Jiaojia Faults are two well-known regional ore-controlling faults; they have opposite dip direction, and intersect at a depth of 4500 m. Fracture alteration zones have striking geophysical differences relative to the surrounding county rocks. The two faults extend down along dip direction in a gentle wave form, and appear at some steps with different dips. These steps comprise favorable gold prospecting areas, consistent with a step metallogenic model. Six deep-seated gold-prospecting targets are delineated, i.e. Jincheng-Qianchenjia, Xiaoxizhuang-Zhaoxian, Xiyou-Wujiazhuangzi, Xiangyangling-Xinlicun, Panjiawuzi and Miaojia-Pinglidian.

PORPHYRY COPPER (-MOLYBDENUM-GOLD) DEPOSIT PROSPECTIVITY IN ZHASHUI-SHANYANG MINERALIZATION BELT,QINLING MT., NW CHINA

The paper focuses on the geological setting, forrning environment, petrochemistry, isotope, etc. of the Yangshanian intermediate-acid porphyry intrusion in ZhashuiShanyang mineralization belt. The alteration type and zone of the intrusion and its host rocks have been studied, and the characteristics of the known copper (-molybdenum-gold) mineralization occurrence have been investigated. Hence the metallogenetic factors and ore prospectivity have been evaluated by comprehensive study of the metallogenic geology and correlation with the rnega-porphyry copper(-molybdenum) deposits in the world.

Diagenesis-Mineralization and Ore Prospecting of the Yangla Copper Deposit, Yunnan Province, Southwest China

The large-scale Yangla copper deposit, located in the central part of the Sanjiang Tethys polymetallic belt, is structurally controlled by the Jinsha River Fault and Yangla Fault. This deposit consists of seven ore blocks, including the Beiwu, Nilv, Jiangbian, Linong, Lunong, Tongjige and Jiaren. The Cu metal prospective reserves of the Yangla deposit are above 1 million tons. There are widely distributed Indosinian granodiorite and also many gabbro-diabase dikes and few quartz porphyries exposed in the Yangla ore district. The ore-hosting rocks are diopsode-garnet skarn, sericitie sandy slate and metamorphic quartz sandstone of the first member of the Devonian Linong Formation. Ore bodies occur as layered, stratoid, lenticular and veined shapes, and are strictly controlled by rocks, strata and structures.

Geological characteristics and metallogenic prospect of marine volcanic rock-type copper deposits in eastern Kunlun Mountains area, Xinjiang

The Katelixi Cu-Zn deposit is a marine volcanic rock-type copper deposit discovered for the first time in the Tokuzidaban Group in eastern Kunlun Mountains area. It is hosted in the Lower Carboniferous Tokuzidaban Group volcanic strata. The orebodies are obviously controlled by the strata and their ore-bearing rocks are a suite of greyish-green mafic tuffs, generally parallel-stratiform, stratoid and lenticular in form, occurring in limestone as well as in the contact between limestone and carbon-bearing siltstone. This ore deposit possesses distinct characteristics of marine volcanic rock sedimentaion. The geological, petrochemical and REE characteristics of its occurrence pro-vide strong evidence suggesting that this deposit is of marine volcanic rock sedimention origin, basically identical to those of some typical marine volcanic rock-type copper deposits in Xinjiang and other parts of China. Marine vol-canic rocks are well developed in the Lower Carboniferous Tokuzidaban strata in eastern Kunlun Mountains area. In addition to this deposit, we have also found a number of copper polymetallic ore deposits or occurrences in associa-tion with marine volcanc activities in many places where there is a good metallogenic prospect. A breakthrough in the understanding of ore prospecting and genesis has not only filled up the gap in prospecting this type of ore depos-its in this area, but also is of great significance in directing exploration of this type of ore deposits in this area.

Assessment of Prospecting Potentiality for Superlarge Continental Volcanic Rock-Type Uranium Deposits in China

The superlarge continental volcanic rock\|type uranium deposits, which were discovered abroad long ago, have not yet been reported up to now in China. This is an important problem that needs to be urgently solved by uranium geologists at present. In this paper, on the basis of analyzing the metallogenic settings and geological conditions of the superlarge continental volcanic rock\|type uranium deposits discovered in the world along with the metallogenic characteristics of those of the same type in China, the space\|time distribution patterns of continental volcanics and the metallogenic potential of main tectono\|volcanic belts in China are discussed, and a synthetic conclusion has been drawn that there is a possibility to discover the superlarge continental volcanic rock\|type uranium deposits in China. Moreover, it is evidenced that the Ganhang, Nanling, Yanliao, Da Hinggan Ling and other tectono\|volcanic belts possess favorable geological conditions for the formation of ssuperlarge ore deposits of the continental volcanic rock type. The intersecting and overlapping locations of the aforementioned main belts with other tectono\|volcanic (\|intrusive) belts are the most potential areas where the superlarge continental volcanic rock\|type uranium deposits would be found.

A Prospecting Mineralogy Study: Arsenopyrite In Endogenetic Gold Deposits

Arsenopyrite is one of very important and common auriferous minerals in endogenetic gold deposits. In seven gold deposits, the prospecting typomorphic characteristics of arsenopyrite, such as morphological typomorphism, composition typomorphism, pyroelectricity typomorphism and so on, were established. The crystal form of arsenopyrite is simple, and the form symbols mainly are {101}, {120}, {210}, {140}, {230}, {012}, etc. The smaller grain and poor crystal form arsenopyrite indicates the better auriferous characteristics. The major elements (Fe, As and S) of gold-bearing arsenopyrite usually show Fe/As+S>0.5,As/S<1 which deviates from its theoretical value. The most important trace element is Au and next is Ag in arsenopyrite, and they often show the positive correlation. The pyroelectricity of arsenopyrite can reflect the mineralization epoch, and it also is related to the crystal form and granudarity.

Geochemical Characteristics,Genesis of Concealed Cu-rich Ore Body in the Jinchuan Deposit,Northwestern China,and Its Prospecting

The Jinchuan deposit is hosted by the olivine-rich ultramafic rock body, which is the thirdlargest magmatic sulfide Ni-Cu deposit in the world currently being exploited. Seeking new relaying resources in the deep and the border of the deposit becomes more and more important. The ore body, ore and geochemistry characteristics of the concealed Cu-rich ore body are researched. Through spatial analysis and comparison with the neighboring II1 main ore body, the mineralization rule of the concealed Cu-rich ore body is summed up. It is also implied that Cu-rich magma may exist between Nirich magma and ore pulp during liquation differentiation in deep-stage chambers, which derives from deep-mantle Hi-MgO basalt magma. It is concluded that the type of ore body has features of both magmatic liquation and late reconstruction action. It has experienced three stages： deep liquation and pulsatory injection of the Cu- and PPGE-rich magma, concentration of tectonic activation, and the later magma hydrothermal superimposition. In addition, the Pb and S isotopes indicate the magma of I6 concealed Cu-rich ore body originates predominantly from mantle; however, it is interfused by minute crust material. Finally, it is inferred that the genesis of the Cu-Ni sulfide deposit is complex and diverse, and the prospect of seeking new deep ore bodies within similar deposits is promising, especially Cu-rich ore bodies.

东北地区金矿成矿规律及找矿方向

金矿是一种重要的贵金属矿产,也是东北地区优势矿产之一。东北地区金矿资源丰富,分布具有明显的区域性集中趋势,是我国岩金尤其是砂金的重要产区。本文系统收集和整理了已有东北地区金矿地质资料,全面总结了东北地区金矿资源禀赋、矿床类型、时空分布规律、成矿演化,指出了进一步的找矿方向。综合金矿床的工业类型和成因类型,将东北地区金矿床分为砂矿型、岩浆热液型、陆相火山岩型、变成型和受变质型、斑岩型、叠加型及成因暂时未查明的流体型等类型。岩金主要分布于华北成矿省辽东成矿带、华北陆块北缘东段成矿带,吉黑成矿省小兴安岭—张广才岭成矿带、吉中—延边成矿带,大兴安岭成矿省东乌珠穆沁旗—嫩江成矿带等;而砂金主要分布于黑龙江省三江沿岸,大兴安岭成矿省东乌珠穆沁旗—嫩江成矿带、吉黑成矿省佳木斯—兴凯成矿带、小兴安岭—张广才岭成矿带等。东北金矿具有多旋回、多期次成矿的特点,按其规律可划为太古宙、元古宙、加里东期、华力西期、印支期、燕山期、喜马拉雅期等7个成矿期。划分了13个成矿系列,22个成矿亚系列,22个三级预测区,显示出良好的成矿条件和找矿前景。

Discovery of Liquid Cryptoexplosive Breccia in the Pulang Porphyry Copper Deposit of Yunnan Province and its Prospecting Significance

The Pulang porphyry copper deposit,located in the Gezan tectonic-magmatic arc and south of the Yidun island arc,southwest of Sanjiang metallogenic belt in Yunnan province,is a super-large porphyry copper deposit.

Experiment and Achievement Enlightenment of Integrated Prospecting of Carbonate-Type Lead-Zinc Deposits in the Sichuan-Yunnan-Guizhou Region of China

Mississippi-Valley＇s carbonate-type （MVT） lead-zinc deposits are the most important type of lead-zinc deposits in the southwest of China. In 2013, China Geological Survey Bureau deployed a project named ＂Experimental Investigation of Integrated Prospecting Technology for Concealed Carbonate-Type Lead-Zinc Deposits in the Region of Sichuan, Yunnan and Guizhou Provinces＂. This project has been implemented by the Chengdu Center of China Geological Survey since 2013, and the project has run for 3 years. The general objective of this project is to establish an effective and adaptable integrated prospecting methodology （including geological, geophysical and geochemical techniques） in search for deep concealed lead-zinc deposits.

大兴安岭大杨树火山盆地西缘金矿的发现及找矿意义

大兴安岭中生代火山盆地是区域上寻找浅成低温火山热液型金矿床的有利区,前人在大杨树火山盆地西缘开展1∶5万矿产调查时,已圈定出张点和扎罗梅2处远景区。利用零星的槽探工程开展物化探异常验证:在张点矿区发现1条稳定延伸的含金石英脉,长约0.95 km,视厚度为5~15 m,最高金品位为88.25×10^(-6);在扎罗梅矿区发现2条金矿体、1条金矿化体、1条银矿体,其中I号和II号金矿体被推断为同一条金矿体,长度大于600 m,视厚度为2~3 m,最高金品位为5.83×10^(-6),IV号银矿体视厚度为4.0 m,最高品位为(50.90~310.00)×10^(-6)。综合分析两个矿区的土壤化探异常和激电中梯测量视极化率异常特征,并与区域上三道湾子等金矿床的成矿地质条件进行对比,认为张点和扎罗梅矿区的金矿点具有中—大型成矿资源潜力。大杨树火山盆地边缘金矿点的发现可为大兴安岭火山岩带的金矿勘查部署提供参考,促进勘查及研究程度的提高,有助于实现找矿突破。

胶东金矿与中生代区域性花岗岩关系及成矿预测和找矿方向

胶东地区是世界著名的金矿资源基地,截至2023年6月已累计探明金矿资源量已达5757余吨。与金矿成矿密切的中生代花岗岩分布广泛,岩石类型多样,也是山东省最发育、最典型的地区。本文对胶东地区金矿与中生代区域性花岗岩空间展布、形成时代和形成环境等关系进行了分析研究。区域性广泛分布的中生代花岗岩为晚侏罗世玲珑期(166~146 Ma)、早白垩世早期郭家岭期(135~123 Ma)、早白垩世晚期伟德山期(123~110 Ma)和崂山期(118~108 Ma),研究认为区域性岩浆事件一般持续10 Ma左右,而重熔型花岗岩一般持续20 Ma,反映了由基底岩石熔融到侵入结晶的2个阶段,它有一个由基底固体岩石熔融的过程,大致也需要10 Ma,既固体岩石熔融10 Ma,熔浆活动上侵结晶10 Ma。玲珑期重熔型花岗岩是扬子板块和华北板块碰撞的期后产物,郭家岭期岩浆事件代表了中国东部中生代构造体制转换的开始,伟德山期岩浆事件代表了构造体制转换的高峰期,崂山期岩浆事件代表了构造体制转换的结束期。86.8%的金矿赋存在玲珑期花岗岩中,6.9%的金矿赋存于郭家岭期花岗岩中,玲珑期花岗岩和郭家岭期花岗岩Au元素背景值明显高于伟德山期花岗岩和崂山期花岗岩。矿石硫与玲珑期花岗岩、郭家岭期花岗岩范围相近,特别是与玲珑期花岗岩大范围重叠,具有岩浆热液硫同位素变化小的特点,说明矿石硫主要源为玲珑期花岗岩、郭家岭期花岗岩。矿石铅主要为再活化的下地壳铅,即前寒武纪结晶基底铅,有幔源铅加入。金矿成矿年龄有162~146 Ma、133~120 Ma、120~115 Ma、112~105 Ma共4个区间范围,与胶东地区四期区域性花岗岩形成时间对应,成矿年龄一般晚于成岩年龄3~5 Ma。根据胶东金矿及多金属矿与岩浆热液事件对应关系,划分为玲珑金成矿期、郭家岭金成矿期、伟德山金及多金属成矿期和崂山多金属成矿期。胶东地区金矿主要是新太古代变质地层和古元古代底部片岩层位经过重熔作用金元素活化、迁移、富集和郭家岭期岩浆作用成矿。基于以上成矿作用认识,根据地球化学块体理论,对胶东金矿潜力进行了估算,胶东地区3000 m以浅金矿潜力约为1.8万t,同时对胶西北深部金矿进行了系统预测,预测3000 m以浅金资源量3997 t,5000 m以浅7497 t。通过地质综合研究,栖霞地区中新太古代变质岩下部有隐伏玲珑期花岗岩,根据金矿主要赋存在玲珑期花岗岩中的空间展布,S、Pb等同位素以及玲珑期花岗岩是金矿成矿直接围岩或母岩的认识,该地区变质岩中发育众多的石英脉型中小型金矿和矿(化)点,可能是浅部或顶部矿体的表现,认为该地区具有良好的成矿背景和潜力,是胶东地区今后金矿找矿的重要地区和方向。并建议在该地区部署地震和大功率激电剖面及地质科研钻探,查清一系列NE向断裂和地质结构,为金矿找矿提供科学依据。

辽东半岛五龙金矿外围电性特征及找矿意义

辽东五龙金矿经过80余年的开采,矿山资源储备严重下滑,后备资源不足问题日益突出,亟需查明矿区深部和外围矿产资源。通过在v163号脉西北和东南两侧以及100号断裂南侧开展瞬变电磁法测量工作,构建了相应的二维和三维地电模型,分析了矿区低阻异常特征;结合前人研究成果,推断出金矿成因类型和下一步找矿方向。研究结果表明:v163号脉西北方向P0剖面上低阻区是由包括163号脉西北段的细粒闪长岩脉群引起的,属于石英脉型成矿的可能性较大;100号断裂南侧三维地电模型中的低阻区域与大孤顶子金矿矿化点相对应,该低阻区向北侧深部规模增大,异常未封闭,表明该区域北侧深部具有良好的找矿前景,值得进一步开展研究工作;v163号脉东南方向的三维地电模型中,低阻异常值在数量级上明显低于前二者,推测为蚀变带引起,后经工程验证孔揭露,该区域纵向存在多层不连续的硅化蚀变岩,最大厚度为41m,蚀变类型有硅化、绢云母化、绿泥石化以及不同程度的黄铁矿化。研究表明,五龙金矿不仅存在石英脉型金矿体,还有蚀变岩型金矿体,后者可能是该矿区下一个找矿的主要方向。

内蒙古额济纳旗格日勒图铜多金属矿成因及找矿潜力

内蒙古珠斯楞地区为我国北山成矿带的东延区,格日勒图铜多金属矿是近些年在该区发现的重要铜多金属矿床,矿床赋存于上石炭统白山组上段(C_(2)b^(2))火山岩中。为研究该矿床的成因类型,本文开展了矿石矿物组构、矿石地球化学、石英包裹体和矿物电子探针等分析测试。结果表明,矿石中的脉石矿物主要为石英,石英中包裹体气液比15%~40%,均一温度156℃~395℃,平均温度为308.7℃。盐度(wt%NaCl)2.41~6.64,平均为4.34,属于低盐度中高温流体。石英中的气体包裹体可分为两种类型,一类为N_(2)+CH_(4),另一类为N_(2)。综合研究认为该矿床的成因类型为岩浆热液型矿床。铜多金属矿体在垂向具有明显的分带,上部发育高品位的次生富集带,金属硫化物主要为蓝辉铜矿、辉铜矿、黄铁矿、闪锌矿和少量的砷黝铜矿、黄铜矿等;下部主要为黄铁矿、闪锌矿、方铅矿、黄铜矿和砷黝铜矿等。矿床的形成可初步划分为火山沉积成岩期、岩浆热液成矿期和表生成矿期。研究认为在该矿床深部及外围地区依然具有较大的找矿潜力。

辽东硼成矿带研究进展

辽东地区是我国重要的硼矿资源产地,赋存硼矿的胶-辽-吉带古元古时期处于活动陆缘环境。辽东硼矿成因为沉积变质再造矿床,硼物质源于蚀变洋壳、俯冲沉积物、蛇纹石化地幔楔等俯冲洋壳系统的富硼地体,在洋壳向克拉通俯冲过程中,硼质在弧前释放进入岛弧火山系统参与热液循环,通过海底热泉等热液方式汇集于火山盆地形成含水硼酸盐初始矿层并被随后的火山沉积覆盖保存。在区域变质变形过程中,含水硼酸盐脱水重结晶并就位于变形构造形成的有利部位富集成矿。辽东硼同位素组成特征反应了对源区储库重硼的继承性,因此,用于探讨矿床成矿地质环境更具意义,而非用于海相和非海相沉积简单的对比。同产于含硼岩系中的含铜硫铁矿矿床沉积时间稍晚于硼矿床,两者空间上呈错位产出,据此可辅助找矿预测工作。区域上虎皮峪-红石砬子-清河复式背斜是辽河旋回多幕变形作用叠加形成的,宏观上控制含硼岩系硼矿床的空间分布。通过总结以往工作,建立了辽东硼矿床成矿模式和找矿模型,分析了找矿方向,特别指出的是,部分盖县岩组地层出露地区,深部具有寻找隐伏硼矿的探索空间,未来找矿前景可期。

新疆阿尔金西段瓦石峡南锂铍稀有金属矿成矿背景与勘查进展

锂、铍等稀有金属矿产是重要的战略矿产资源。近年来,在阿尔金地区发现了多处稀有金属伟晶岩型矿床,已成为我国一处新的稀有金属成矿带,但调查研究水平总体较低。通过对阿尔金造山带的成矿动力背景的讨论,得出阿尔金造山带的稀有金属成矿作用涵盖了多个不同的造山运动构造演化阶段,证明该区域具备良好的稀有金属成矿条件,并具有巨大的找矿潜力。通过对位于阿尔金西段的瓦石峡南锂铍稀有金属矿进行勘查评价,发现其具有大型远景:瓦石峡南锂铍稀有金属矿体主要赋存于绿片岩相-角闪岩相变质岩系中的伟晶岩脉中,矿床类型为花岗伟晶岩型稀有金属矿床;已有勘查成果显示此矿床目前推断的稀有金属资源量达到中型以上矿床规模,并且随着勘查工作的进行,在深部及外围还有极大增储空间。研究成果对在阿尔金造山带内寻找同类型矿床具有借鉴意义。

我国原生金刚石矿找矿勘查实践与研究新进展

2013年召开的“全国金刚石找矿勘查现场研讨会”,标志着我国新一轮原生金刚石矿找矿勘查工作的开始。近十年以来,原生金刚石矿找矿勘查实践与研究取得了一系列新进展:安徽栏杆地区和辽宁瓦房店地区新增一批原生金刚石资源量,进一步提升了我国金刚石资源保障能力;新划分出辽宁第Ⅳ金刚石成矿带和山东平邑—费县金刚石成矿带,在全国多个地区发现了新的找矿线索,进一步拓展了金刚石原生矿的找矿空间;进一步完善了构造解析-三维建模-工程验证、高分辨率遥感信息提取等综合找矿方法,形成了深部找矿和发现隐伏岩体的新思路;含矿岩体成因研究、金伯利岩(钾镁煌斑岩)侵位模型、金刚石原产地研究等取得了新认识;年代学研究表明,我国含金刚石母岩的成矿时代从古生代延伸到晚中生代,具有显著的多期次成矿特征。此外,文章根据近十年来金刚石找矿勘查与研究取得的新进展及存在的新问题,提出了今后原生金刚石找矿勘查与研究的相关建议。

伊犁盆地南缘阔斯加尔地区砂岩型铀矿勘查历程与找矿启示

阔斯加尔地区是近年来在乌库尔其铀矿床往东探索扩大而新发现的砂岩型铀成矿地段。文章通过对阔斯加尔地区不同勘查阶段工作部署以及找矿思路的梳理,结合矿体地质特征,归纳总结铀矿体发现的经验和启示。阔斯加尔地区于20世纪50年代开始勘查工作,前期探索查证为后期的铀矿勘查工作提供了线索和依据。2008年开始带钻查证工作,通过资料梳理,重新预测了铀成矿潜力地区,落实了铀矿产地;2012-2013年进入瓶颈期,经历综合研究和系列基础图件编制,细化了控矿因素,预测了成矿有利地段;2016-2020年为突破期,矿体规模持续扩大,连续揭露到多个较富大的矿体,平米铀量持续提升,资源量规模达中型。阔斯加尔地区是伊犁盆地南缘“乌库尔其-蒙其古尔中部矿集区”的重要组成部分,西接乌库尔其矿床,南邻扎吉斯坦矿床,是伊犁盆地南缘“外围找矿,就矿找矿”的重要地区。中侏罗统西山窑组上段铀矿体为区内主要矿体,其规模较大,资源占比高。通过对已知矿床外围进行不断的探索和查证,搜集整理老资料、开展综合研究与编图等重要的经验和启示,可以作为寻找类似铀成矿地区的借鉴。

安徽宿松县柳坪磷矿地质特征及找矿标志

柳坪磷矿是宿松地区典型磷矿床之一,其矿床资源储量规模达中型,其磷矿赋存于宿松岩群的柳坪岩组中,分为上下四层。该磷矿为“海州式”沉积变质型矿床,受岩层和次级褶皱的控矿条件制约,具有地层、岩性组合、磷锰共生、地球化学异常等找矿标志。矿区部分地段深部延伸稳定且未完全控制,显示深部仍然具有较大找矿潜力。