机器学习与成矿预测:以闽西南铁多金属矿预测为例     

张振杰  成秋明  杨玠  武国朋  葛云钊 《地学前缘》2021,28(3):221-235

作为近年来爆炸式发展的方法模型,机器学习为地质找矿提供了新的思维和研究方法。本文探讨矿产预测研究的理论方法体系,总结机器学习在矿产预测领域的特征信息提取和信息综合集成两个方面的应用现状,并讨论机器学习在矿产资源定量预测领域面临的训练样本稀少且不均衡、模型训练中缺乏不确定性评估、缺少反哺研究、方法选择等困难和挑战。进一步以闽西南马坑式铁矿为实例论述基于机器学习方法的矿产预测基本流程:(1)通过成矿系统研究建立成矿模型,确定矿床控矿要素;(2)通过勘查系统研究建立找矿模型,并为评价预测提供相关的勘查数据;(3)通过预测评价系统研究,建立预测模型,并提取预测要素;(4)利用机器学习模型对预测要素进行信息综合集成,获取成矿有利度图;(5)对预测性能和结果进行不确定性评估;(6)找矿靶区/成矿远景区圈定及资源量估算。最后,总结建立以地学大数据和地球系统理论为指导,以“地球系统-成矿系统-勘查系统-预测评价系统”为研究路线的基于地学大数据的矿产资源定量预测理论和方法体系的研究愿景。  相似文献   

四川会理拉拉铜矿找矿预测模型构建与找矿示范     

陈辉  林鲁军  庞振山  程志中  薛建玲  陶文  马一行  龚灵明  申红涛 《地学前缘》2021,28(3):309-327

勘查区找矿预测理论与方法体系是基于全国129个典型矿床的深入研究,以及在勘查项目实践验证基础上总结而形成的一种特别适合生产找矿第一线使用的有效方法。该方法以成矿作用内因(元素的地球化学特征)和外因(地质作用类型)相结合的思路,构建以成矿地质体、成矿构造与成矿结构面和成矿作用特征标志为主要内容的找矿预测地质模型。四川会理地区位于扬子板块西缘,区域成矿地质条件优越,经历多期构造事件叠加,形成了一系列独具特色的铁铜矿床。近年来,在拉拉铜矿的深部及外围已取得了重大找矿突破和进展。本文以会理拉拉铜矿为典型实例及深部找矿预测成果示范,阐述该方法在深部找矿预测中的具体应用过程,得出了如下认识:早期成矿地质体为赋矿火山岩(河口群钠长岩类),成矿构造与成矿结构面主要为基(中)性火山岩与沉积岩的界面及可能的喷溢口;热液叠加期成矿地质体推测为深部隐伏岩体,成矿构造与成矿结构面主要为褶皱、断裂和裂隙。在总结成矿作用特征标志基础上,建立了拉拉铜矿勘查区找矿预测地质模型。通过与地质和物探方法相结合,圈定红泥坡南部为找矿靶区,经钻探验证,发现厚大矿体,打开了区域找矿空间。  相似文献   

穿透性地球化学在干旱戈壁荒漠覆盖区的应用 ——甘肃花牛山铅锌矿试验实例     

刘汉粮  张必敏  王学求  孙彬彬  张振海  刘东盛 《地球学报》2021,42(4):545-554

干旱戈壁荒漠区地处我国西北部地区,天山、北山、祁连山三大多金属成矿带横贯其中,成矿条件优越,找矿尤其是找隐伏矿的潜力巨大,但受风成砂土的影响,很难获知覆盖层下方的矿化信息.穿透性地球化学已被证实是有效寻找隐伏矿的方法,其被定义为能探测深部隐伏矿体发出的直接信息的勘查地球化学理论与方法技术.笔者在花牛山铅锌矿开展土壤微细粒全量测量、金属活动态测量(水溶态测量、黏土吸附态测量、铁锰氧化物态测量)和地电化学测量多种穿透性地球化学勘查方法实测工作,结果表明,5种测量方法分析数据主成矿元素(铅、锌)异常衬度高,变异系数大,富集成矿可能性大,地球化学异常与深部隐伏矿体位置吻合,相比较而言,土壤微细粒全量测量效果最好,黏土吸附态测量、铁锰氧化物态测量和地电化学测量效果较好,水溶态测量效果稍差;所选方法技术针对干旱戈壁荒漠区寻找隐伏铅锌矿是有效的.气固介质中内生条件下的纳米金属微粒的发现为利用土壤作为采样介质的穿透性地球化学方法技术(土壤微细粒测量、金属活动态测量)提供了理论基础.电提取泡塑载体中大量的微米级的黏土矿物颗粒发现,以及微量元素异常与铁、铝等常量元素异常高度一致,初步推断地电化学测量提取过程是对黏土矿物颗粒选择性吸附过程.  相似文献   

黔西南水银洞爆破角砾岩筒与金元素超常富集     

邱小平  刘世川  魏密 《地球学报》2021,42(6):849-858

水银洞金矿床曾被认为是滇黔桂地区最有代表性的微细浸染型金矿(卡林型金矿),然而矿床的金品位明显高于一般意义上的卡林型金矿床,且金矿体与气液爆破角砾岩关系密切.气液爆破角砾岩呈垂直筒状产状,两侧断裂矿化带呈向上扩张的"喇叭口"状成矿空间,富金矿体紧密围绕角砾岩筒分布.根据野外和显微镜观察,角砾岩块成分复杂与显著磨圆.气液角砾岩筒的角砾岩显著富集金、稀土、亲地幔过渡元素Ti、Cr、Ni、Co、V等,以及Zr、Hf等,明显地区别于围岩,反映出深源流体快速上升的气液爆破角砾岩的特征,角砾岩筒实际上具备含金成矿流体的上涌通道的功能.岩筒中早期角砾岩的角砾含Au达18×10–6,属于深部金矿体的爆破碎块,显示出水银洞金矿床可观的深部找矿勘探前景.  相似文献   

巴音戈壁盆地塔木素铀矿床含矿砂岩成岩作用类型、演化序列及其对铀成矿的约束     

张成勇  夏菲  严兆彬  邓薇  聂逢君  张鹏飞  文振宇  刘波  戴明建  封志兵 《地球学报》2021,42(6):907-920

勘查和研究发现部分砂岩型铀矿床中不仅有表生氧化流体作用还存在深部流体的参与,这类砂岩型铀矿床蚀变类型多样且成因复杂.塔木素砂岩型铀矿表生流体和深部流体活动都很明显,砂岩普遍固结且后生蚀变类型独特,因此,恢复成岩成矿事件及其演化过程,对揭示铀沉淀富集机理至关重要.本文通过镜下鉴定、电子探针、扫描电镜分析等,系统研究了塔木素矿床含矿砂岩成岩作用特征与后生蚀变矿物生成序列,重塑了成岩成矿事件的演化过程.研究结果显示,塔木素矿床砂岩中压实作用较弱而胶结作用很强,重结晶作用普遍,是造成目的层致密的主要原因,赤铁矿、褐铁矿化、碳酸盐化、石膏化是该地区主要的胶结类型.将该地区的成岩演化划分为沉积-早成岩阶段、早期氧化流体作用阶段、热流体改造阶段和晚期氧化流体弱改造阶段.成岩环境由弱碱性向酸性环境转变的过程中的氧化还原过渡部位是造成铀沉淀的关键,大规模的氧化作用是矿床形成的基础,后期热流体活动对早期形成的低品位铀矿石进行叠加改造,是成矿的关键环节.  相似文献   

物探技术在布敦乌拉隐伏矿产勘查中的应用效果     

刘永祥  刘福胜  王欣  韩晓阳  谢磊 《中国煤炭地质》2021,(3):60-63

内蒙古西乌珠穆沁旗布敦乌拉矿区多为第四系覆盖。在该矿区多金属勘查中,依据土壤地球化学圈定的矿化异常布置激电中梯测量,圈定1处激发极化率异常区,长度约890m,宽度约520m,位于已知断层F 1与推断断层F 2之间。采用可控源音频大地电磁测深剖面对该激电异常进行探测,解释视充电率多峰异常与反演电阻率高低跳跃对应区域为矿致异常区。通过钻探验证,发现银多金属矿床资源储量523.93万t,取得了良好的地质找矿效果。  相似文献   

福建凤山矿区石墨矿地质特征及控矿因素分析     

程远慧 《中国煤炭地质》2021,(3):13-19

通过对福建省漳平市凤山矿区石墨矿近年来硐探、钻探等地质资料系统的梳理,在分析矿区地质特征和矿体特征的基础上,深入研究了石墨矿的控矿因素。研究认为该区石墨矿是由赋存于中二叠统童子岩组的无烟煤经过高温、高压作用进一步变质而成的。煤层受到岩浆热变质作用使碳物质(煤)分解,重新富集形成以隐晶质(土状)为主的隐晶质石墨矿,因此本区石墨矿的控矿因素是温度和构造。由于过往对福建煤系石墨资源的研究程度不够深入,造成大部分煤系石墨矿划归煤矿,致使石墨矿资源被浪费,本次通过野外地质勘查、采样样品测试等工作,确定了凤山矿区为煤系石墨矿,为下一步勘探工作提供有力依据,为合理开发利用矿产资源指明新的方向。  相似文献   

Geological characteristics and ore genesis of Houfangzi graphite deposit in Northwestern Hebei Province     

ZHANG Xingkang  FAN Yupeng  JIN Song  JIA Zhenghai 《中国地质调查》2021,7(6):20-26

Houfangzi graphite deposit is located in the middle of the graphite metallogenic belt in the northern margin of North China Block in Hebei Province, which belongs to regional metamorphic type graphite deposit. In this paper, through rock-mineral determination, IP ladder sections and exploratory trench survey, the authors have discussed its metallogenic geological characteristics and ore body characteristics, and analyzed its ore genesis. The research results show that the ore bodies are mainly in the graphitic marble of Dongjingzi Formation of Hongqiyingzi Group, which are stratified and controlled by layers, with NE trend and NNW inclination. The IP anomaly shows that Houfangzi graphite deposit is characterized by low resistance and high polarization. Ore bodies are stable and of big scale, and their fixed carbon content ranges from 1.42% to 3.28%, which has the potential to be a large graphite deposit. The ore-forming material came from granulite and graphite marble, while the regional metamorphism is the main mineralization of Houfangzi graphite deposit, with the enrichment and increasement caused by late magmatic activity and migmatization.  相似文献   

Geology and mineralization of the Sanshandao supergiant gold deposit (1200 t) in the Jiaodong Peninsula,China: A review     

《China Geology》2021,4(4):686-719

The Jiaodong Peninsula in Shandong Province, China is the world’s third-largest gold metallogenic area, with cumulative proven gold resources exceeding 5000 t. Over the past few years, breakthroughs have been made in deep prospecting at a depth of 500–2000 m, particularly in the Sanshandao area where a huge deep gold orebody was identified. Based on previous studies and the latest prospecting progress achieved by the project team of this study, the following results are summarized. (1) 3D geological modeling results based on deep drilling core data reveal that the Sanshandao gold orefield, which was previously considered to consist of several independent deposits, is a supergiant deposit with gold resources of more than 1200 t (including 470 t under the sea area). The length of the major orebody is nearly 8 km, with a greatest depth of 2312 m below sea level and a maximum length of more than 3 km along their dip direction. (2) Thick gold orebodies in the Sanshandao gold deposit mainly occur in the specific sections of the ore-controlling fault where the fault plane changes from steeply to gently inclined, forming a stepped metallogenic model from shallow to deep level. The reason for this strong structural control on mineralization forms is that when ore-forming fluids migrated along faults, the pressure of fluids greatly fluctuated in fault sections where the fault dip angle changed. Since the solubility of gold in the ore-forming fluid is sensitive to fluid pressure, these sections along the fault plane serve as the target areas for deep prospecting. (3) Thermal uplifting-extensional structures provide thermodynamic conditions, migration pathways, and deposition spaces for gold mineralization. Meanwhile, the changes in mantle properties induced the transformation of the geochemical properties of the lower crust and magmatic rocks. This further led to the reactivation of ore-forming elements, which provided rich materials for gold mineralization. (4) It can be concluded from previous research results that the gold mineralization in the Jiaodong gold deposits occurred at about 120 Ma, which was superimposed by nonferrous metals mineralization at 118–111 Ma. The fluids were dominated by primary mantle water or magmatic water. Metamorphic water occurred in the early stage of the gold mineralization, while the fluid composition was dominated by meteoric water in the late stage. The S, Pb, and Sr isotopic compositions of the ores are similar to those of ore-hosting rocks, indicating that the ore-forming materials mainly derive from crustal materials, with the minor addition of mantle-derived materials. The gold deposits in the Jiaodong Peninsula were formed in an extensional tectonic environment during the transformation of the physical and chemical properties of the lithospheric mantle, which is different from typical orogenic gold deposits. Thus, it is proposed that they are named “Jiaodong-type” gold deposits.©2021 China Geology Editorial Office.  相似文献   

赣中新衡萤石矿床成矿流体特征研究：来自流体包裹体及氢氧同位素的证据     

张栋梁  吴德海  潘家永  吴赞华  陈光飞  欧阳斌  费磊  袁庚红  胡昊  余明军 《地质论评》2024,70(S1):70-72

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