The Xihuashan Au-Cu deposit is among the important polymetallic metallogenic prospects discovered in recent years in Haiyuan, Ningxia Hui Autonomous Region. There is strong tectonic activity and mineralisation of Au, Cu, Pb and Ag in the study area, so this deposit is a typical polymetallic mineralised concentration zone. To investigate the nature and origin of the ore-forming fluids and the genesis of the deposit in the Xihuashan Au deposit, a comprehensive study was conducted on the rare earth elements (REE) and trace elements, and H-O-S isotopes of the ore-bearing lamprophyres and ores in the study area. The results show that the ore-bearing lamprophyres have the total rare earth element (Sigma REE) contents ranging from 84.77 x 10-6 to 461.01 x 10-6, the light rare earth element (LREE) contents ranging from 64.50 x 10-6 to 424.81 x 10-6, the heavy rare earth element (HREE) contents ranging from 20.27 x 10-6 to 36.20 x 10-6, the delta Eu values range from 0.62 to 0.98, and the delta Ce values range from 0.86 to 1.00. These suggest a multi-source origin for these lamprophyres. The delta DV-SMOW values of hydrothermal quartz range from -72 parts per thousand to -92 parts per thousand, and the delta 18Ofluid values range from 6.7 parts per thousand to 12.0 parts per thousand, indicating that the ore-forming fluids are multi-sourced. Furthermore, the S isotope results imply that the ore-forming materials are largely derived from magmatic sources, with a minor contribution from the wall rocks. Based on the geological evolution of the North Qilian orogenic belt, the intense tectonic-magmatic activity during the late Caledonian period-closely associated with gold mineralisation-provided a crucial heat source and energy. This activity triggered the mobilisation, migration and subsequent enrichment of siliceous and mineralised components from the Haiyuan Group. These components were ultimately concentrated within NE- and nearly E-W-trending transtensional fault zones. After the formation of the earliest mineralised quartz veins, decreasing temperature and pressure, along with ongoing mineralisation, alteration and tectonic activities, led to the fragmentation of the initially formed quartz veins. Subsequent magma differentiation resulted in late-stage mineralisation, accompanied by the emplacement of lamprophyre veins and the formation of new mineralised quartz veins. The gold-mineralizing elements underwent multistage enrichment from different sources to form different types of gold mineralisation. Compared with a typical orogenic gold deposit, the Xihuashan Au deposit is a product of orogenic movement in the North Qilian orogenic belt and is an orogenic-type Au deposit.

The study of the fluid inclusions of W-Mo deposits in the mineralization area of Ningshan-Zhen'an , Shaanxi Province, China shows that the gas-liquid two-phase inclusions are mainly present in W-Mo deposits, and the ore-forming fluid can be divided into four types: high-temperature type, middle-high-temperature type, middle-temperature type and low-temperature type. The formation depths of the W-Mo mineralization range from 4.2 to 8.4 km. The boiling and mixing of fluid may have been important mechanisms for the formation of W-Mo mineralization. The skarn-type mineralization is dominated by magmatic water, the quartz-vein-type mineralization includes both magmatic water and meteoric water, and the meteoric water is more involved in the quartz-fluorite-vein-type, beryl-quartz-vein-type and pegmatite-type mineralization. Magma is the main source of sulfur; that is, magma is the main source of mineralization. Combined with the metallogenic setting and geological characteristics of typical ore deposits, in the process of structural system transformation in South Qinling, the ore-forming magma fluid in the Late Indosinian-Yanshanian period was uplifted and emplaced along the NW-WNW direction and NE-NNE direction, and eventually, NW-WNW fault-controlled skarn-type W-Mo mineralization and quartz-vein-type W-Mo deposits accompanied by greisenization, albitization and potash feldspathization formed.

Current research in deep learning, which is widely used in mineral prospectivity prediction, focuses on obtaining high-performance models to predict mineral resources. However, because the network structure and depth of different algorithms differ, there are some differences in the correlation between the spatial pattern of ore-generating geological big data and the spatial location of discovered ore deposits; this causes instability in the prediction. To solve this problem, this paper proposes the use of ensemble learning to synthesize convolutional neural network algorithms and self-attention mechanism algorithms for mineral prospectivity prediction. In this study, 14 factors related to gold mineralization were selected, 10 types of geochemical exploration data (Au, Ag, As, Cu, Pb, Zn, Hg, Sb, W, and Mo) and 4 geological factors (ductile shear zones, brittle fault zones, mineralization-alteration body zones, and metamorphic quartz sandstone zones). Six classical convolutional neural network models (MobileNet V2, ResNet 50, VGG 16, AlexNet, LeNet, and VIT) were used to extract the features of the metallogenic factors. After training, a network model with an accuracy over 94% was obtained. Then, the mineral prospectivity of an unknown area was predicted. The models were evaluated according to their accuracy. Using these results, ensemble learning was performed, areas with high potential were obtained, and the prospectivity prediction map was drawn. This map provides guidance for gold exploration in the Bawanggou mine area of the northern Hanyin gold orefield, South Qinling, China. This comprehensive method can effectively leverage the advantages of various models, fully extract the internal relationships of deep-level mineralization, and has extremely high extensibility. The calculated results can be made more scientific and stable by adding more mineralization factors and introducing an algorithm with the new structure in the future.

近年来,南秦岭镇安西部地区发现了棋盘沟、核桃坪、东阳等大中型钨多金属矿床.其中棋盘沟大型钨矿床以石英脉型为主,深部可见矽卡岩型矿化,前人仅对其中的石英脉型钨矿进行了年龄测试,深部的矽卡岩型钨矿尚未开展年代学研究工作.本文以棋盘沟钨矿床为研究对象,选取两类矿石中与白钨矿、辉钼矿密切共生的金云母进行 39Ar-40Ar同位素测年.结果显示,矽卡岩型矿石中金云母坪年龄为 190.1±0.6 Ma(MSWD=1.28),石英脉型矿石中金云母坪年龄为188.6±0.6 Ma(MSWD=1.42),均为早侏罗世成矿,且石英脉型钨矿成矿时间略晚于矽卡岩型钨矿.该成矿期处于南秦岭成矿带陆内碰撞造山向伸展转变的转折期,代表着一期重要的、尚未被广泛关注的印支末期的岩浆热液钨钼成矿事件,应在今后的找矿工作中予以重视.

海南富文金矿床位于华南褶皱系五指山褶皱带北缘,主要出露早白垩世鹿母湾组(K1l)含砾碎屑沉积岩.金矿体呈脉状和似层状赋存于鹿母湾组砂岩层间破碎带中.为进一步探讨富文金矿的成矿物质来源,对石英脉型矿石、赋矿围岩鹿母湾组碎屑沉积岩及岩浆岩进行主量、微量和稀土元素测试分析.结果显示:矿石与围岩地层、岩浆岩具有相似的微量元素变化趋势以及相似的稀土配分模式,预示着成矿与地层、岩浆岩关系密切.早白垩世石英闪长岩、细粒花岗岩和碎屑沉积岩均为矿体的形成提供了成矿物质,矿床类型为岩浆热液型金矿.

Jiurui ore concentration area is an important part of the middle and lower reaches of Yangtze River metallogenic belt.The study area of Pengshan polymetallic ore field is located in the south of Jiurui ore concentration area, which is rich in mineral resources, but the structural pattern is controversial.In this paper, based on the comprehensive analysis of geological and geophysical characteristics, it is proposed that Pengshan ore field is controlled by the structure of magmatic core complex, and the core of Pengshan magmatic core complex upheaval-detachment structure is composed of elliptical granitoid intrusive rock mass, which was a hidden uplift in the middle Yanshanian period and was shaped in the late Yanshanian period.The peripheral shallow sedimentary rocks are in a domed zonal distribution around the magmatic core complex.The peripheral fault zone tends to deviate from the direction of magmatic core complex and shows a shovel distribution, indicating the detachment structure characteristics.The halo type ore belt types of Pengshan ore field, with the concealed granitic body in the core as the center, the change of high temperature ore to low temperature ore occurs in the surrounding, such as arsenite（arsenopyrite）-tin ore-lead-zinc ore-fluorite ore-barite ore and so on, which is also the result of mineral enrichment along the multi-level detachment faults, and the mineralization occurs in the inner and outer contact zone of the magmatic core complex, forming skarn type, porphyry type and hydrothermal vein type Sn-Pb-Zn polymetallic deposits in the structural relaxation stage.

Taking the metamorphic core complex of Niushan-Fenghuangshan（NFMtCC）in the southern Qinling Mountains and the North Niushan magmatic core complex（NMgCC） as examples, this study compares the characteristics and ore-controlling effects of the two types of core complexes. The research method is to compare and analyze the structural community, metamorphic degree, magma emplacement and deformation era, structural hierarchy and evolution, and ore control characteristics of the nuclear complex, combined with ore control structure alteration lithofacies mapping and dating research. The results indicate that the two types of core complexes have similar structural styles, but there are significant differences in their tectonic communities and evolution. The core of Niushan-Fenghuangshan metamorphic core complex is the Neoproterozoic Wudang rock group and Yaolinghe rock group medium deep metamorphic rock, with Neoproterozoic quartz diorite and Caledonian pyroxene diabase strain, indicating that it was formed in Neoproterozoic or Caledonian. There are detachment faults and ductile shear zones between the core complex and the surrounding Sinian Devonian shallow metamorphic rock. The Meiziya Formation of the Silurian system is a combination of shallow metamorphic and strongly deformed rock slices, with three stages of newly formed foliation and replacement, including multi-level ductile shear, solid-state rheology, detachment thrust strike slip deformation. The core and periphery of the North Niushan magmatic core complex are shallow metamorphic rock, and four intrusive rocks of Neoproterozoic, early Paleozoic, Triassic and Jurassic are found in the core and periphery by mapping and testing. There are two phases of intrusive rock related to the magmatic core complex: Triassic-Early Jurassic monzonitic granite stock（180.2±3.6 Ma, 176.0±1.9 Ma） and Late Jurassic granite vein（156.5 Ma）. This research has found that the magma emplacement, ductile shear deformation, and thermal metamorphism accompanied by the magma core complex, as well as the increase of metamorphic phenocrysts, the distribution of natural gold along the S 2 plane, and the hydrothermal alteration of gold mineralization, are all concentrated in the Late Triassic-Jurassic, indicating the spatiotemporal correlation characteristics of the brittle ductile shear deformation, overpass type magma, thermal vertical accretion, and hydrothermal alteration of the magma core complex during the relatively new era of intracontinental orogeny, as well as the direction of deep exploration.

Pyrite is a ubiquitous metal sulfide in gold mines, and its trace element content information can reveal the composition and crystallization characteristics of related minerals and fluids when the minerals are formed. Therefore, pyrite and trace elements related to gold mines at different stages The information can be used to predict the type of deposit. In addition, the related research has a long history, and a large amount of research materials have been accumulated. However, due to the limitations of research ideas and methods, traditional methods often have problems of no solution or multiple solutions. With the development and promotion of big data ideas, researchers have tried to use machine learning algorithms to solve such problems, and have achieved good results. In this study, based on the idea of deep learning, adata set of trace elements of pyrite was established and conducted in-depth research. By means of “component data visualization” and “data enhancement”, it solved the problems encountered by predecessors when using deep learning methods for such classification tasks. The resulting data imbalance problem and the problem that the convolutional neural network cannot directly read the data. This paper compares and analyzes the accuracy and effect of gold ore type classification task using pyrite trace element composition data based on four convolutional neural network models（Mobilenet V2, Resnet50, Vgg16 and VIT）. It is found that the convolutional neural network algorithm can be based on The pyrite composition data can perform more accurate classification tasks for different types of gold deposits. This method has higher accuracy and generalization ability than the traditional graphical method. By predicting the type of gold deposits, it can save costs for prospecting exploration and deep prediction work, and also provide deep learning for the application and promotion of geological and mineral resources research. The new idea has certain promotion value.

《地球科学概论》是高校地质学类专业学生迈入大学学习的第一门专业基础课程,持续的课程建设和教学改革意义重大.课程团队遵循以学生学习和发展为中心的教学理念,尊重学生主体性,紧扣课程目标,丰富教材资源,拓展教学空间,提升教学质量.采用线上线下混合小班教学、专题研讨、课堂及野外实践充分结合的方式,提高学生参与度和课堂实效性,强化综合素质培养.凝练专业家国情怀和科技成就,构建多维度课程思政,实现价值引领、知识教育、能力培养的有机统一.

野外实习是培养合格地质人才的重要环节和专业特色,对培养学生兴趣、巩固专业知识、提高实践能力等有着不可替代的作用.然而传统野外地质教学实习中存在效率低、成本高、互动性和共享性差等问题,虚拟仿真教学很好地弥补了此缺陷.通过以汉中梁山野外地质实习基地为例,介绍了长安大学地质学类专业野外地质实习的发展现状,实习目的和任务,分析了传统野外地质实习存在的问题,探讨了汉中梁山野外地质实习虚拟仿真教学平台建设的思路和拟解决的关键问题.

This study investigates the deformation characteristics of two brittle–ductile shear zones in the Cigou-Zaoyang gold area of the South Qinling Mountains, China, using both macroscopic and microscopic methods to examine aspects such as fractal geology, quartz thermometry, and quartz barometry. The results show that the strike of the shear zones is consistent with that of the F 2 fault. The shear zones show the transposition of a sericite foliation, microscopic microfolding, an S–C fabric, undulatory extinction of quartz, deformation lamellae in quartz, mechanical twinning of quartz, mylonitic textures, early microfolding of narrow quartz veins, a fracturing of large biotite crystals, quartz grain boundary migration and crystallization, and static recovery–crystallization of quartz. According to the sequence of mineral crystallization and the order of structural development, the tectonic activity of the brittle–ductile shear zone and the later brittle deformation process can be divided into six stages: (1) ductile shear; (2) high temperature and pressure; (3) high temperature and low pressure; (4) strong ductile shear under low temperature and high pressure; (5) low temperature and brittle deformation; and (6) epithermal activity in a tensile environment. The fractal dimension values of quartz grains show that the temperature increased from southwest to northeast with quartz grain boundary migration and recrystallization, and all samples reached the lower amphibolite facies of metamorphism. The mean differential paleo-stress values were 6.89–13.65 MPa, as inferred from simulations of quartz recrystallization. The mineralization occurred through the formation of a local extensional zone by strong ductile shear in the schist, which provided space for hydrothermal mineralization. Stronger rock deformation is related to a higher gold grade, higher sericite content, and higher metal mineral content. Both the ductile shear deformation and the concentration of hydrothermal mineralization are multistage as this is the only way high-grade ores can be formed. The combination of processes also resulted in high, although subeconomic, gold contents in rocks surrounding the brittle–ductile shear zones.

The Shuangwang gold deposit, with more than 70 tons of Au, is located in the Fengxian-Taibai ore concentration area in the Qinling Orogen of central China, hosted in a Northwest-trending breccia belt. Fragments of the breccia body are cemented by ankerite, albite, quartz, calcite, and pyrite. Four metallogenic stages are identified in mineral paragenesis: quartz-albite, ankerite-pyrite-albite, pyrite-quartz-calcite, and fluorite-anhydrite. Pyrite, as the main gold-bearing mineral, was formed in the syn-ore and post-ore stages, which are analyzed for trace elements. The experimental results show that Au (0.02 to 11.68 ppm), As (198.45 to 5502.86 ppm), Ag (0.00 to 1.56 ppm), Co (0.02 to 1002.75 ppm), Ni (0.15 to 646.30 ppm), Cu (0.00 to 64.76 ppm), Sb (0.00 to 4.67 ppm), Zn (0.23 to 260.59 ppm), Pb (0.00 to 10.42 ppm), Se (0.00 to 386.24 ppm), and Bi (0.00 to 47.72 ppm) are enriched in syn-ore pyrite much more than in post-ore pyrite, especially arsenic. The high arsenic content and rapid crystallization of pyrite may be the main reasons for precipitation of gold. δ34SV-CDT values of pyrite formed in stage II (PyII) vary from 11.1 to 15.2‰ (mean = 12.9‰), while those for pyrite formed in stage III (PyIII) vary from 11.1 to 13.5‰ (mean = 12.0‰). In situ sulfur isotope analysis indicates that sulfur of the Shuangwang deposit comes from the wallrock, mixed with sulfur from magma.

A W-Mo mineralized region is located along the northern margin of the South Qinling tectonic belt of China. WMo mineralization occurs mainly in Cambrian–Ordovician clastic and carbonate rocks, and the ore bodies are structurally controlled by NW–SE-and NNE–SSW-striking faults. Evidence for magmatism in the area is widespread and is dominated by intermediate–felsic intrusives or apophyses, such as the Dongjiangkou, Yanzhiba, Lanbandeng, and Sihaiping granitic bodies. Quartz-vein-type mineralization and fault-controlled skarn-type mineralization dominate the ore systems, with additional enrichment in residual deposits. At present, there are few or insufficient studies on（1） the age of mineralization,（2） the relationship between intermediate–felsic granite and W-Mo mineralization,（3） the source of ore-forming materials, and（4） the metallogenic and tectonic setting of the mineralized area. In this paper, we present geochronology results for numerous intrusive granitic bodies in the South Qinling tectonic belt. U-Pb zircon geochronology of the Lanbandeng monzogranite and Wangjiaping biotite monzogranite yields ages of 222.7 ± 2.3 and 201.9 ± 1.8 Ma, respectively. In contrast to the Late Triassic age of the Lanbandeng monzogranite, the age of the newly discovered Wangjiaping biotite monzogranite places it at the Triassic–Jurassic boundary. Re-Os molybdenite geochronology on the Qipangou W-Mo deposit yielded a model age of 199.7 ± 3.9 Ma, indicating the deposit formed in the early Yanshanian period of the Early Jurassic. Granitoid intrusions in the mineralized area are characterized by composite granite bodies that crystallized at ca. 240–190 Ma. While there were multiple stages of intrusion, most occurred at 210–220 Ma, with waning magmatic activity at 200–190 Ma. The Re-Os age of molybdenite in the region is ca. 200–190 Ma, which may represent a newly discovered period of W-Mo metallogenesis that occurred during the final stages of magmatism. The heat associated with this magmatism drove ore formation and might have provided additional ore-forming components for metallogenesis（represented by the Wangjiaping biotite monzogranite）. Ore materials in the mineralized area were derived from mixed crustal and mantle sources. Enrichment of the region occurred during intracontinental orogenesis in the late Indosinian–Yanshanian, subsequent to the main Indosinian collision. At this time, the tectonic environment was dominated by extension and strike-slip motion.

基于近年来东昆仑祁漫塔格地区在找矿工作中遇到的问题,开展矿田构造的研究为深部及外围找矿提供依据已经迫在眉睫.在本次矿田构造研究中,选取构造发育的虎头崖矿田进行构造应力场的分析,利用野外地质分析和区域构造解析法、矿田断裂构造解析、节理统计分析法、共轭剪节理分析法、化石应变测量统计分析以及韧性变形分析等,首次对区内各断裂、节理及韧性变形带的构造应力场进行研究,厘定出成矿前、成矿期和成矿期后的3期次,共8个阶段的构造应力场,主要为:成矿前:(加里东—华里西期)北北东—南北→北北东→北西→北北西;成矿期:(华里西—印支期)北北东—南北→北北西;成矿后期:(燕山—喜山期)北西—北西西→北东东—东西→南北;并为未来区内的构造应力场的研究提出了确定原则;最后在区域大地构造演化基础上,归纳出研究区构造应力演化过程.在该矽卡岩型铜多金属矿田成矿期构造北西西、近东西、北东东向断裂交汇部位及其派生断裂是寻找矿的有利构造部位.

广泛分布于南祁连的志留纪巴龙贡噶尔组的形成时代和构造归属存在很大分歧,为了说明土尔根达坂巴龙贡噶尔组英安岩-流纹岩形成时代及地质意义,本文选择代表性岩石进行了主微量元素和LA-ICP-MS锆石U-Pb年代学分析.地球化学结果表明,巴龙贡噶尔组火山岩为高钾钙碱性过铝质岩石,在成岩过程中经历了一定的结晶分异作用.火山岩微量元素表现出不同程度的富集K、Pb和轻稀土元素(LREE),相对亏损高场强元素(HFSE)Zr、Ce、Nb,具有明显的P、Ti负异常.LREE/HREE之比为6.98～10.13,δEu介于0.40～0.54显示负异常,表明稀土元素分馏明显;各样品稀土曲线具有相似的右倾型配分模式,反映为同源岩浆产物.三个样品LA-ICP-MS锆石U-Pb谐和年龄分别为438.1±2.2Ma,403.0±2.6Ma,404.9±2.8Ma,说明火山岩的形成地质时期为早志留世-早泥盆世.综合对比得出原志留纪巴龙贡噶尔组应进行解体及重新认识,土尔根达坂地区巴龙贡噶尔组火山活动与南部柴达木花岗岩岩浆活动近于同期,两者可能都与柴达木陆块与中南祁连板块碰撞造山带上不同块体之间的伸展、滑塌等一系列岩浆侵入活动相关.

The airborne hyper-spectral survey system CASI/SASI, which has an integrated system for gathering both image an spectral data, is at the cutting edge developments in the remote-sensing field. It can be used to directly identify surface objects based on diagnostic spectral characteristics. In this paper, the CASI/SASI were used in the Huaniushan gold-silver-lead-zinc ore district–Gansu to produce a lithologic map, identify altered minerals, and map the mineralized-alteration zones. Radiometric correction, radiometric calibration, atmospheric correction (spectral reconstruction), and geometric corrections were carried out in ENVI to pre-process the measured data. A FieldSpec ® Pro FR portable spectrometer was used to obtain the spectral signatures of all types of rock samples, ore deposits, and mineralized-alteration zones. We extracted and analyzed the spectral characteristics of typical alteration minerals. On the basis of hyper-spectral data, ground-spectral data processing, and comparative analysis of the measured image spectrum, we used the spectral-angle-mapping (SAM) and mixture-tuned matchedfiltering (MTMF) methods to perform hyperspectral-alteration mineral mapping of wall rock and mineralized-alteration-zone hyperspectral identification. Hyperspectral- remote- sensing geological- classification maps were produced as well as distribution maps of all kinds of alteration minerals and mineralized-alteration zones. Based on geological comprehensive analysis and field investigations, the range of mineral alteration was proven to be the same as shown by the remote-sensing imagery. Indications are that airborne hyperspectral- remote-sensing -image CASI/SASI offer good application results and show a promising potential as a tool in geological investigations. The results will provide the basis for hyperspectral remote-sensing prospecting in the same or similar unexplored areas.

This study focuses on the iron ore of Taxkorgan and Heiqia in the West Kunlun mountains as a case study, for the application of WorldView−2 and IKONOS remote sensing images as major data sources in the fabrication of a standard image map and in the adoption of image enhancement methods to extract information on the ore-controlling factors and mineralization, to interpret remote sensing for the mineral resources in these areas. ASTER, WorldView−2, and IKONOS data were applied for the extraction of alteration anomaly information. With an appropriate amount of field sampling and verification tests, this was used to establish a remote sensing geology prospecting model, that would provide the basis for future remote sensing of metallogenic belts in West Kunlun in the hope of discovering similar minerals. Survey results showed four additional iron ore mineralization belts could be delineated in the Taxkorgan area. A comparative analysis conducted for part of the field confirmation and the known mineral deposits indicated good reliability. In Heiqia, a siderite-haematite mineralization zone was observed with copperlead- zinc formation, 60-km in length and 200–500 m wide, which includes several mineralized bodies. The ore bodies, appear as stratoid, lenticular, or podiform morphologies and were located in the transition site from clastic to carbonate rocks of the D segment in the Wenquangou Group. The ore bodies generally occur within 40°–50° strike and 68°–81° dip, in accordance to the strata. The length of the single body varies from several hundred metres to more than 9500 m. Its exposed thickness on the surface ranges from 2–50 m, and the general thickness was approximately 15 m. The surface ore minerals were mainly haematite and limonite, with a small amount of siderite. Therefore, high-resolution remote sensing technology is suitable for iron ore geological and mineral remote sensing surveying. It is advantageous in both high-ground resolution of optical characteristics and a certain spectral recognition capability, and is effective not only for information extraction from a large area, but also for recognition of local mineralization outcrops. Therefore, high-resolution remote sensing technology is valuable for popularization.

南秦岭成矿带镇安西部钨钼金多金属矿田发现多有晚印支—燕山期多期构造—岩浆—热液流体叠加成矿富集现象.经过近几年国家和陕西省整装勘查区找矿会战调研及成果集成综合研究发现,该区带经历了新元古代、加里东期、华力西期、印支期、燕山期和喜马拉雅期多期构造运动及其相应的成岩成矿叠加富集事件.对宁陕—镇安西部一带钨钼金矿集区或多金属矿田而言,其主要是受到印支晚期—燕山期发生的陆内造山期#型立交桥式多期构造—岩浆—气液叠加富集成矿事件,影响较为显著.且主要是在宁陕—镇安—山阳—柞水—旬阳北部一带形成了许多与中酸性小岩体或隐伏花岗岩斑岩—矽卡岩—远端浅成中低温热液型有关的钨钼金矿床.通过多个项目调研和成果集成,我们识别出一组成岩成矿时代主要在侏罗纪,且与隐伏花岗质岩浆活动有关的斑岩—矽卡岩—远端浅成中低温热液型矿床,矿床可分为:东阳式、桂林沟式、月河坪式、付家沟式、观花坪式、东川式六类.成矿时代主要集中在早侏罗世200～190 Ma,成矿模式具有"井"字形立交桥式成矿叠加富集特征.这是南秦岭带发现的以燕山期为主的陆内造山期钨钼金成矿作用事件,具有其特殊的侏罗纪陆内造山叠加富集成矿构造背景和作用过程.燕山期陆内造山成矿动力学转换的特殊背景、构造—岩浆—热液流体演化过程和热力作用叠加深部找矿的科学意义十分重要.

黔西南地区是中国卡林型金矿的主要产地之一,架底金矿作为黔西南地区近年来在玄武岩中新发现的卡林型金矿床,其金的赋存状态一直备受关注.前人研究表明,含砷黄铁矿是架底金矿的主要载金矿物,然而对架底金矿载金黄铁矿以及金的赋存规律一直缺乏深入的研究.文章结合野外实际调研以及室内显微岩相观察研究,首先对矿区黄铁矿进行了期次的划分;然后利用电子探针微区成分分析方法对不同期次的黄铁矿进行研究,结果显示:架底金矿的黄铁矿中,S、As具有明显的负相关性,Au、As存在一定的相关关系,成矿前黄铁矿与成矿期、成矿后的黄铁矿核部具高S、Fe,低As、Au等相似的特征,成矿期黄铁矿的环带具高As、Au的特征,与成矿后的环带(高As不含Au)相比较具明显差异,两者属于不同的热液事件.据此判断矿区载金黄铁矿的结晶顺序为:草莓状低砷无环带黄铁矿→含砷环带黄铁矿(含金)以及均质无环带的细粒黄铁矿→高砷环带黄铁矿(不含金).这一结论对架底金矿找矿勘查工作具有一定的指示意义.