The Jinqingding gold deposit in eastern Jiaodong is a significant gold mineralization within the Muping-Rushan metallogenic belt. This study integrates structural analysis and trace element geochemistry of sulphides to elucidate ore-controlling mechanisms and metallogenic models. The deposit occurs as pyrite-quartz veins and polymetallic sulphide veins/disseminations hosted in biotite monzonitic granite, controlled by the NNE-striking Jiangjunshi-Quhezhuang fault. Structural analysis reveals that mineralization was controlled by conjugate shear joints, tension fractures, and en & eacute;chelon faults formed under a tectonic stress field with sigma 1 oriented NE-SW. LA-ICP-MS trace element analysis of pyrite reveals dual geochemical affinities-high-temperature magmatic signatures (elevated Co, Ni, Ti) and medium-low temperature hydrothermal signals (enriched As, Pb, Bi)-suggesting episodic fluid inputs from magmatic-hydrothermal and meteoric sources. Rare earth elements (REEs) are low in pyrite and show slight LREE enrichment. The results suggest that the main ore-controlling structures formed under a stress field with sigma 1 oriented NE-SW during the Early Cretaceous, and the mineralization may be related to episodic fluid pulses, as reflected by the changes in trace elements during the crystallization of pyrite. Furthermore, this study reveals an NEE-trending set of potential ore-controlling structures for epizonal gold mineralization, which is of great significance for regional gold exploration in Jiaodong.

Growing evidence suggests that extensional/transtensional settings are favorable for the formation of tin deposits, yet the underlying geodynamic mechanism remains equivocal. The Pingna W-Sn deposit, found in the underexplored interior of the giant tin belt within the Youjiang Basin, South China, offers a unique opportunity to explore and better constrain the current geodynamic model for tin mineralization. This deposit, composed of NW- to NWN-striking vein swarms with W-Sn mineralization, is hosted in the Middle Triassic clastic rocks without igneous rocks near its mineralization. Structural analysis indicates that the Youjiang fold-and-fault belt and the ore-related structures in the Pingna deposit experienced five deformation phases (D1-D5). The pre-ore NE-striking compression (D1; rv = r3) initiated fault-fracture meshes, followed by NE-striking extension (D2), while NW-striking compression (D3; rv = r2) enhanced the vertical connectivity of the meshes. Syn-mineralization E-W extension (D4; rv = r1) facilitated upward through-going flow and hydrothermal fluids infilled the meshes, forming a fault-vein system. The mineralized veins were cut across by post-ore WNW-striking oblique fault with sinistral and normal components (D5). The meshes dictated Sn-W orebodies localization. Hydrothermal veins formed in three stages: (I) muscovitization-bordered tin-dominated quartz vein swarms along the Pingna fault; (II) W-dominated lit-par-lit vein system; and (III) barren calcite veins crosscutting the former veins. The Pingna W-Sn mineralization formed during the Late Cretaceous as constrained by the cassiterite (Cst1) U-Pb age of 95.6 +/- 2.4 Ma (2r, MSWD = 1.2), muscovite (Ms1) 40 Ar-39 Ar plateau age of 93.9 +/- 0.1 Ma (2r, MSWD = 1.7), and molybdenite Re-Os age of 92.9 +/- 1.2 Ma (2r, MSWD = 0.3). Outward lateral zoning of the Sn-W mineralization, as well as associated muscovitization and silicification implies the epicenter of hydrothermal fluid is near the No. II vein swarm. Contemporaneous felsic dykes coupling with the inferred intrusions demonstrate that the Pingna deposit is a distal hydrothermal W-Sn deposit. The releasing bend of the NW-striking Pingna fault controlled the distribution of tin-dominated mineraliza-tion, while the anticlines controlled the tungsten-dominated mineralization. Our findings suggest that the localization and formation of the Pingna W-Sn veins were controlled by Late-Cretaceous regional transtensional stress field and polyphase deformation, rather than previously proposed local extension of the Youjiang Basin. The discovery of the Pingna W-Sn deposit highlights the interior of the Youjiang Basin as a promising area for tungsten-tin exploration.(c) 2025 China University of Geosciences (Beijing) and Peking University. Published by Elsevier B.V. on behalf of China University of Geosciences (Beijing). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). double up arrow Corresponding author at: Laboratory of Dynamic Diagenesis and Metallogen-esis, Institute of Geomechanics, Chinese Academy of Geological Sciences, No. 11, Minzudaxue South Road, Beijing 100081, China. E-mail address: xiaochanghao1986@126.com (C. Xiao). https://doi.org/10.1016/j.gsf.2025.102006 1674-9871/(c) 2025 China University of Geosciences (Beijing) and Peking University. Published by Elsevier B.V. on behalf of China University of Geosciences (Beijing). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Danchi metallogenic belt is one of the most important nonferrous metal industry bases.It is to be the research focus owing to the large scale of Sn and Sb metal budget.The genesis of Sn-polymetallic mineralization during the Late Cretaceous and the relationship between Zn-Sn and Sb mineralization in the belt remain unclear.The Bawang deposit,a recently discovered paleokarst infilled type deposit,occurs in the west limb of the Wuxu anticline.Basing on the earlier study of structural analysis,mineralogy,and cassiterite U-Pb ages,in this study it presents element mapping of ores by micro-XRF(μ-XRF)analysis,and in situ U-Pb laser ablation-magnetic sectorfield-inductively coupled plasma mass spectrometer(LA-SF-ICP-MS)ages of calcite during the antimony mineralization stage.Micro-XRF analysis revealed that the sphalerite,cassiterite-quartz,and arsenopyrite mineralization have taken place in order in the Bawang deposit.Calcite U-Pb dating provides a lower intercept ages of 62.8±1.1 Ma(MSWD=2.6;2σ).Combined with previous ages of Zn-Sn mineralization,mineralogy,and μ-XRF analysis,the Zn-Sn mineralization is 30 Ma earlier than Sb mineralization.The pressure contrast existed between the fluid pressure at the site of ore deposition and the fluid pressure within the concealed intrusion is the key dynamics of fluid flow for the tin mineralization.

The Bawang deposit, a newly discovered Fe-Zn-Sn deposit occurred in the paleokarst in the Youjiang Basin, South China, offers an excellent opportunity to understand the ore-forming process and genesis of this unique tin mineralization, thus enriching the tin mineralization theories. Mineralogy, X-ray photoelectron spectroscopy (XPS), and laser ablation-inductively coupled plasma-mass (LA-ICP-MS) analysis were performed on sphalerite to investigate the fluid evolution and mineralizing process of the Bawang deposit. The formation of the deposit involved hydrothermal-cassiterite-sulfides and oxidation periods. The hydrothermal-cassiterite-sulfides period is dominated by the mineralization of Zn- (stage 1), Sn- (stage 2), and Sb- (stage 3) in order. Three types of sphalerite were identified in these hydrothermal stages. Mineralogical studies and spectrum data show that the massive sphalerite in stage 1 (Sp1) is euhedral coarse-grained and characterized by high Fe contents (9.67-15.69 wt%), with obvious pyrrhotite blebs, pyrite laths, stannite and/or chalcopyrite solid solutions. The sphalerite with 5.56-11.31 wt% Fe contents in stage 2 (Sp2) occurs as fine-grained, euhedral to subhedral crystals (15-50 mu m) and coexists with cassiterite, arsenopyrite, and quartz. The sphalerite in stage 3 (Sp3) is characterized by low Fe content (0.59-2.99 wt%) and is generally micro-fine-grained (10-30 mu m) associated with stibnite, sulfosalts, and carbonates. LA-ICP-MS analyses of sphalerite suggest that Sp1 and Sp2 have similar characteristics and are enriched in Fe, Cu, Sn, Ga, and Cd, whereas Sp3 is enriched in Sb, Pb, Ag, Bi, and Tl. The principal component analysis (PCA), boxplots, and bivariate plots of trace elements from sphalerite, combined with previous Raman spectroscopy data for fluid inclusions and H-O-Cd isotopic compositions, indicate two types of ore-forming fluids were involved in the mineralization of the Bawang deposit. The early Fe-Zn-Sn-Cu-In-rich fluids originated from granitic magma and underwent Zn- and Sn-dominated mineralization in order in a slowly cooling closed system. The later hydrothermal fluids with the addition of oil field brine were enriched in Sb, Pb, Ag, and Bi elements in the Sb-sulfosalts-carbonates stage in an open system with a drop in temperature. The mineralization process of the Bawang deposit can be concluded as follows: The early ore-forming fluids derived from an inferred concealed intrusion infilled into the paleokarst (below 350 m of the altitude) and caused the massive euhedral ferroan sphalerite (stage 1) to precipitate. The deposition of sphalerite decreased sulfur fugacity (fS2) in a slowly cooling closed system, and increased relative oxygen fugacity (fO2) which promoted cassiterite to precipitate in stage 2. The foreign hydrothermal fluids lowered the temperatures of residual ore-forming fluids due to the addition of oil field brine. Then the Pb-Sb sulfides and Pb-Sb-Ag-Bi-bearing sulfosalts (stage 3) crystallized at shallow depths (350 to 500 m of the altitude).

在大量典型矿床剖析的基础上,以矿物学、岩石学、矿床学、构造地质学、地球化学等基础理论为指导,以大量实地观察和实验数据为支撑,通过总结矿山深部和外围找矿实践和典型矿床研究成果,按照成矿作用内因和外因相结合的辩证思维,成矿作用时间、空间、物质能量相统一的综合思维,以及元素地球化学分类和找矿预测矿床分类的比较思维,提出成矿地质体、成矿构造和成矿结构面、成矿作用特征标志等概念.成矿地质体是形成矿床主要矿产、决定主成矿阶段空间位置的成矿地质作用的实物载体,划分为沉积作用、火山作用、岩浆作用、变质作用和大型变形作用形成的 5 类成矿地质体.成矿结构面是赋存矿体的各类界面,包括构造界面、岩性界面、物理化学转换界面;成矿作用特征标志是能够直接指示矿体赋存位置和对找矿预测具有特殊意义的标志.依据成矿地质作用对中国主要矿床类型进行梳理划分,归纳总结了主要矿床类型的地质特征,构建了反映矿体赋存位置的成矿地质体-成矿结构面-成矿作用特征标志"三位一体"找矿预测地质模型.在此基础上,提出勘查区找矿预测的工作方法,对矿床学研究、找矿预测、矿产勘查工作具有重要的指导意义.

The South China block (SCB) experienced the tectonic transition from the Paleo-Tethys to the Paleo-Pacific tectonic domains during the Mesozoic, but the transition process is hotly debated. The Youjiang fold-and-thrust belt (YFTB), in the interior of the Youjiang Basin in the southwestern SCB, is located in a junction of these two tectonic domains and thus witnessed their tectonic evolution. It also separates the northern thin-skinned structures from the southern thick-skinned structures in the basin. Therefore, the YFTB is an intriguing window into the Mesozoic evolution in the southwestern SCB and the Mesozoic tectonic transition of the SCB. In this study, we conduct structural analysis at the middle of the YFTB and discuss the Mesozoic tectonic transition of the SCB. Four phases of deformation are identified in the YFTB during the Mesozoic. The first phase of deformation (D1) is characterized by a series of conjugate joints, NW–SE trending thrust faults and folds resulting from NE–SW shortening that was related to the collision between the SCB and Indochina block. The second phase of deformation (D2) is manifested by the pre-existing NW–SE striking thrust faults transformed to normal faults and the Late Triassic mafic magmatism. Our structural observations, combined with previous geochronological data for mafic dykes, suggest the study area experienced post-orogenic extension in the Late Triassic. The third phase of deformation (D3), accompanied with the westward subduction of the Paleo-Pacific oceanic plate, is represented by a series of conjugate joints and NE–SW-striking faults formed by NW–SE compression. As a result of the continuous subduction of the Paleo-Pacific plate and its subsequent slab rollback, the fourth phase of deformation (D4) is featured with normal faults, magmatic-hydrothermal activities, and regional mineralization, which are associated with the nearly E–W extension setting. Our study results indicate that, in the Early Mesozoic, the Youjiang Basin was dominated by the Paleo-Tethys domain and then transitioned to the Paleo-Pacific domain. Together with the magmatic lull between the Triassic and the Early-Middle Jurassic identified in the SCB, we propose that the tectonic transition process manifested in the YFTB more likely initiated in the Early Jurassic.

The Danchi fold-and-thrust belt, Guangxi, South China, contains the Mangchang, Dachang, and Wuxu large and giant Sn-polymetallic districts. It hosts more than 1.2 Mt of ore grading 1 % Sn, 6.23 Mt Zn at 2.4 %, and 1.13 Mt Sb at 1.3 %. Wuxu district is one of the Sb-Zn dominated hydrothermal districts without magmatic rocks exposing in the south of the Danchi belt. Recent drilling and exploring mining have identified a partially Sn mineralization associated with the Zn-Sb mineralization. These works provide an opportunity to evaluate the potential of tin mineralization in the south of Danchi belt and relationship among Sn, Zn, and Sb mineralization. Structural analysis suggests that the Wuxu district underwent at least three deformational phases since the Triassic. The first NE-SW shortening deformation controlled the structural framework of the Wuxu district and is expressed by NWverging thrusts and folds, axial-plane cleavages around the core of the Wuxu anticline, transverse joint sets on the limbs of the Wuxu anticline, and dilational zones in the bedding-fractures. Afterward, an E-W extension stress field produced NS-striking normal faults and reactivated pre-existing NNW-striking faults which were expressed by sinistral top-to-the north sense of shear. During this deformation, some low order dilational spaces of the NWstriking faults and bedding-fractures formed and a syn-kinematic deposition of minerals in these hosting structures to form the ore shoots. The NNW-striking faults, axial-plane cleavages, and large dilational jogs controlled the subvertical large veins in the Jianzhupo deposit. The conjugate joints and inter-bedding fractures in the limb of the Wuxu anticlinorium controlled the branching veinlets and stratiform, paleokarst infilled ores in the Bawang deposit. The post-ore EW-striking faults are not obvious and displaced preceding two-phase structures and ores. Three primary paragenetic stages of hydrothermal process have been recognized: (I) Sphalerite dominated + massive pyrrhotite with euhedral pyrite porphyroblasts, (II) Cassiterite + siderite + arsenopyrite dominated with minor scheelite + quartz + fluorite, and (III) Jamesonite + stibnite + sulfosalt + carbonates. Cassiterite U-Pb dating provided a lower intercept age of 90.2 +/- 3.1 Ma and 90.6 +/- 4.6 Ma for the Jianzhupo and Bawang deposits, respectively. These two ages are consistent with the chronological data of tin-sulfides and orerelated felsic intrusions in the Danchi fold-and-thrust belt, South China. Our studies coupled with previous gravity data suggests a distal magmatic-hydrothermal infilling tin-polymetallic district and indicates that the Wuxu district has great potential for additional tin mineralization.

五龙金矿床是辽东地区最大的石英脉型金矿床,矿区内矿体和岩脉受断裂构造控制明显.容矿构造几何学和运动学特征显示,早白垩世初近NS向挤压形成的近NS向张裂隙、共轭的剪裂隙及派生一对共轭剪裂隙奠定五龙金矿床的构造格架.早白垩世的伸展导致闪长岩脉、三股流岩体、五龙背岩体等沿着先存构造薄弱带内充填,出溶的岩浆热液流体沿着闪长岩充填残余空间继续充填形成石英脉.由于右形剪切变形导致石英脉发生碎裂,并伴随着区域伸展,赋存闪长岩脉和石英脉的构造空间复活,随后花岗岩脉等侵位及出溶的成矿流体通过闪长岩脉上侵的通道运移和充填于石英脉裂隙中并交代闪长岩脉和片麻状二长花岗岩,最后造就了岩脉-矿化-蚀变同构造空间共存的现象.通过成矿期运动学特征显示,NE向断裂带与胶东三山岛金矿带矿体群侧伏规律相似,断裂带北段深部具有找矿潜力.五龙矿区而言,NE向断裂的找矿潜力优于NW向断裂带,NE向断裂下盘平行断裂内张性空间是盲矿体的有利空间.本次首次获得了五龙金矿床辉钼矿-黄铁矿-磁黄铁矿-石英阶段辉钼矿Re-Os同位素模式年龄为125±2.1 Ma.辉钼矿中Re含量为12.8×10-6,显示成矿物质具有壳幔混合的特征.对比前人研究,钼矿化和金成矿均与早白垩世构造体制转换下中国东部强烈的壳幔岩浆活动有关,为同一构造背景下的产物.通过对比胶东地区的成矿系列,辽东地区与胶东地区具有极大的相似性,存在两期钼矿化作用,尤其早白垩世晚期钼矿化可以作为寻找金矿的标志之一.

矿田相当于Ⅴ级成矿区带的地质找矿勘查对象,需要研究"构造与建造共生"的地质现象,建立相应的概念和野外观测方法,有别于"沉积构造岩相"、"岩浆岩相"、"变质岩相"、"大地构造相"、"构造岩相"、"构造相"等理论观点.在长期矿田构造和深部外围找矿实践基础上,研究提出"构造变形岩相"的地质概念.构造变形岩相被理解为"显示构造变形的那部分岩相",是喻示受构造影响的那部分(沉积、岩浆和变质地质作用的)岩相,是包含构造变形及建造特征的地质实体,或构造建造形迹.构造变形岩相,是岩石形变和相变密切共生的地质体,既能反映成岩地质环境又包含成岩物理化学条件,是一种适用于开展"构造结合建造"观测和分析的构造岩石单元.依据地质作用类型,划分了4种矿田构造变形岩相:沉积构造变形岩相、岩浆构造变形岩相、变质构造变形岩相和复成构造变形岩相.根据地质亚相,划分了矿田尺度的27类构造变形岩相.建立矿田构造变形岩相的观测和分析方法,不仅推动了构造结合建造的地质调查和研究,而且为矿田构造向矿田地质学的发展奠定了基础.构造变形岩相研究,用1:1000～1:50000不同精度,可以调查几十至几百平方千米范围的地质找矿问题,直接服务于已知矿床的深部外围找矿.地表结合中段大比例尺填图,三维刻画矿化岩相带的分布特征,成为圈定靶区的最佳途径.在"就矿找矿"的基础上,探讨了中距离找矿的预测方向——构造变形岩相界面成矿带.

The nature and origin of the early Yanshanian granitoids, widespread in the South China Block, shed light on their geodynamic setting; however, understanding their magmatism processes remains a challenge. In this paper, we present both major and trace elements of bulk rock, Sr–Nd–Pb isotopic geochemistry, and zircon U–Pb–Hf isotopes of the low Sr and high Yb A2-type granites, which were investigated with the aim to further constrain their petrogenesis and tectonic implications. Zircon U–Pb dating indicates that these granites were emplaced at ca. 153 Ma. The granites are characterized by high SiO2 (>74 wt.%) and low Al2O3 content (11.0 wt.%–12.7 wt.%; <13.9 wt.%). They are enriched in large ion lithophile elements (LILEs) (e.g., Rb, Th, U, and K) and Yb, but depleted in high field-strength elements (HFSEs) (e.g., Nb, Ta, Zr and Hf), Sr, Ba P, Ti and Eu concentrations. They exhibit enriched rare earth elements (REEs) with pronounced negative Eu anomalies. They have εNd(t) values in a range from −6.5 to −9.3, and a corresponding TDM model age of 1.5 to 1.7 Ga. They have a (206Pb/204Pb)t value ranging from 18.523 to 18.654, a (207Pb/204Pb)t value varying from 15.762 to 15.797, and a (208Pb/204Pb)t value ranging from 39.101 to 39.272. The yield εHf(t) ranges from −6.1 to −2.1, with crustal model ages (TDMC) of 1.3 to 1.6 Ga. These features indicate that the low Sr and high Yb weakly peraluminous A2-type granites were generated by overlying partial melting caused by the upwelling of the asthenosphere in an extensional tectonic setting. The rollback of the Paleo-Pacific Plate is the most plausible combined mechanism for the petrogenesis of A2-type granites, which contributed to the Sn–W polymetallic mineralization along the Shi-Hang zone in South China.

The Xidamingshan cluster is located along the southeastern margin of the Youjiang fold belt,South China.LA-ICP-MS zircon U-Pb dating constrains the crystallization of the quartz porphyry,monzogranite and biotite granite at (93.11 ± 0.64) Ma,(92.92 ± 0.69) Ma and (92.5 ± 1.1) Ma,respectively.They have the same ages with each other within errors,suggesting they are magmatism coevally emplaced during the Later Cretaceous.The εHf(t) values of the quartz porphyry vary from-18.4 to-1.2 with an average value of -7.1,with two-stage model Hf ages (TDM2) of 1 236 to 2 326 Ma with an average value of 1 609 Ma.And the values of the monzogranites and biotite granite are from-19.4 to + 0.3 with an average value of-5.6 and -12.2 to-3.6 with an average value of-6.7,correspond to two-stage model Hf ages (TDM2) of 1 139 to 2 385 Ma and 1 386 to 1 933 Ma,respectively.It indicates that the source material was derived from the partial melting of the Paleo-and Mesoproterozoic crust.Comparing with Hf isotopic characteristics of the Yanshanian granites in the boundary of the Youjiang fold belt,we suggest that all of the granites may have the same magma sources.The average Ce(Ⅳ)/Ce(m) ratios of monzogranite and biotite granite are 23.65 and 33.76,respectively.It suggests that the Luowei concealed intrusion is with low oxygen fugacity.Combined the results from this study coupled with previous research,we proposed that the magmas formed in a regional extensional setting along the southeastern margin of the Youjiang fold belt in the South China during the Later Cretaceous.This caused the partial melting of the Paleo-and Mesoproterozoic crust due to the lithosphere relaxation and collapse,which meanwhile resulted in the large-scale magmatism in the Xidamingshan cluster.In the light of tectonic settings and geochronology,we deduct that the Yanshanian granites along the margin of the Youjiang fold belt are related to both Pacific and Tethyan tectonic domain.

The source and petrogenesis of the Late Cretaceous magmatism and associated Sn-W mineralization in the South China are yet well documented. This paper reports the oxygen isotope compositions of previously analyzed zircons from the Yanshanian felsic intrusions in the Xidamingshan cluster, along the southeastern margin of the Youjiang fold belt, Guangxi, South China. Zircon (Zrn) delta(18) O for quartz porphyry ranges from 5. 31 parts per thousand to 9. 31 parts per thousand, VSMOW, averaging at 7. 61 +/- 2. 17 parts per thousand. delta(18) O-Zrn for beresitization biotite granite, fine biotite granite and medium biotite granite range from 7. parts per thousand to 9. 79 parts per thousand ( average = 8. 36 +/- 1. 33 parts per thousand) , from 5.48 parts per thousand to 9. 27 parts per thousand ( average = 7. 73 +/- 2. 23 parts per thousand) and from 6. 27 parts per thousand to 9. 77 parts per thousand (average =8. 04 +/- 1. 75 parts per thousand) , respectively. Monzonitic granite records a wide range in delta(18) O-Zrn. (5. 48 parts per thousand similar to 10. 99 parts per thousand) with average of 7. 55 +/- 2. 77 parts per thousand. The majorities are greater than the "mantle-like" values (delta(18) O: 5. 3 +/- 0. 6 parts per thousand 2 sigma). Except beresitization biotite granite, five samples have bimodal or multi-modal distribution characteristics and Hf-O plots of zircons have a negative correlation, indicating a crust-mantle interaction. Hf-O isotopic compositions suggest that the source of the magma was mainly derived from partial melting of crustal material with input of mantle-derived components. The mantle-derived melts imply that these melts not only provided necessary heat energy for crust partial melting, but also put got involved in the generation of granitic melts. Low oxygen fugacity as indicated by low Ce(IV)/Ce(III) ratios may be responsible for formation of large Pb-Zn-dominated skarn deposits. Our current research illustrates that combination of zircon Hf-O isotope could more accurately trace the source of magma through distinguish juvenile components and parental magmas derived from reworking of pre-existing crustal material. And zircon O isotope is one of the most efficient techniques to study the metallogenetic regularity.

广西西大明山多金属矿集区是右江褶皱带东南缘近年找矿突破的重要地区,发育凤凰山特大型银矿床、罗维中型钨锌多金属矿床、弄屯大型铅锌矿床及一些中、小型矿床等.其中罗维和弄屯矿床是近年新发现的矿床,矿体分别呈层状赋存于寒武系碎屑岩和呈脉状赋存于寒武系与泥盆系接触界面附近或断裂破碎带中.笔者对矿集区内层状和脉状矿床矿石硫化物铅同位素进行研究,并与赋矿围岩、隐伏二长花岗岩进行对比.铅同位素数据显示:罗维层状矿床矿石硫化物铅同位素组成为:206Pb/204Pb=18.1320～18.5980,207Pb/204Pb=15.5920～15.7988,208Pb/204Pb=38.4041～39.0461;弄屯脉状矿床矿石硫化物铅同位素组成为:206Pb/204Pb=18.3240～18.5060,207Pb/204Pb=15.7321～15.9140,208Pb/204Pb=38.6511～39.2311;二者具有相似的同位素组成,但弄屯矿床矿石硫化物207Pb/204Pb比值略高于罗维矿床矿石硫化物.罗维矿床矿石硫化物铅同位素组成与深部隐伏二长花岗岩铅同位素组成一致;而弄屯矿床矿石硫化物208Pb/204Pb值介于二长花岗岩和地层铅同位同位素组成之间,且矿石207Pb/204Pb比值指示矿石铅可能来源于上泥盆统莲花山组碎屑岩与中寒武统黄洞口组碎屑岩.渌井和大新铅锌矿床显示出异常高的207Pb/204Pb,暗示可能还有其他富铀的地质体为成矿提供放射成因铅,铅同位素特征值(μ值、ω值)揭示矿石硫化物和岩体都具有壳源铅的特征;从垂向上,各矿床距罗维隐伏岩体顶界距离增加,岩浆铅减少,地层铅增加.综合研究认为,西大明山多金属矿集区应属于典型的与深部燕山期岩体侵入有关的岩浆热液充填交代型矿床,成矿物质主要来源于燕山期岩浆和围岩地层.

胶东型金矿是与壳源重熔形成的层状岩浆活动和壳幔混合岩浆活动有关的金矿床,由于成矿时所处构造位置和容矿构造不同而表现为不同的类型,涵盖破碎带蚀变岩型、石英脉型等胶东地区所有金矿床类型.玲珑花岗岩是壳源物质长期处于高温高压下且熔融形成的多物质来源层状岩体,其析出的高温碱性热液溶解金等成矿物质形成初始含矿热液.岩体抬升过程中在其边部往往容易形成拆离带,在岩体中形成脆性断裂构造,均为成矿结构面.后期壳幔混合成因的郭家岭花岗闪长岩,侵入于玲珑层状花岗岩中并一起隆升,使郭家岭花岗闪长岩附近区域的成矿结构面进一步扩大,矿液浓度进一步增大,当上升到特定深度时形成金矿体.玲珑花岗岩和郭家岭花岗闪长岩共同构成成矿地质体,重熔的玲珑层状岩体是成矿基础地质体,郭家岭花岗闪长岩加强了金矿的成矿作用.该认识对开辟胶东新的找矿思路和找矿靶区有很好的指导作用,据此初步预测新的大型拆离带是金矿集中成矿区域,可能成为将来有望取得重大突破的矿集区.

胶东玲珑金矿田地表以下2070 m处发现黑云母二长岩,不仅可以探索该区金矿成矿物质的来源,而且对研究矿床成因提供了新的证据.黑云母二长岩在胶东金矿集中区地表及其他钻孔岩芯中尚未见报道,通过显微镜下观察、鉴定,具有典型的二长结构.非金属矿物主要有斜长石、正长石、石英、黑云母和角闪石;含有较多的金属矿物,主要为原生的黄铁矿和磁铁矿等.黑云母的40 Ar-39 Ar热年代学研究表明,黑云母二长岩的成岩年龄为123.7±1.5 Ma,晚于玲珑花岗岩、滦家河花岗岩和郭家岭花岗岩,与玲珑金矿的形成年龄非常接近.尽管玲珑金矿矿体中的金属矿物并不一定直接来源于黑云母二长岩,但从形成时间分析,二者具有成因联系.黑云母二长岩在侵入过程中可能为金矿的形成提供成矿物质、成矿流体,而且为成矿物质和成矿流体的运移提供能量及驱动力.因而可以推断,黑云母二长岩的侵入与玲珑金矿成矿作用关系密切.

广西地处中国东南部大陆边缘活动带,其地质演化独具特色.多类型的沉积建造,多旋回的构造运动,多期次的岩浆活动和多阶段的成矿作用,组成广西绚丽的区域地质构造景观和丰富的矿产资源.前人(陈毓川等,1993;王登红等,2004;蔡明海等,2005,2006;朱金初等,2006;李华芹等,2008;梁婷等,2011;)对各地区和矿区进行了详细的测年研究,但是对整个广西地区的成岩成矿时代的系统研究相对薄弱.本次研究,在全面收集前人成岩成矿时代数据基础上,对部分重点区带开展成岩成矿数据相关分析测试,查清广西不同地区成岩成矿规律.

呵叻盆地与兰坪—思茅盆地同处藏滇印支褶皱系,成矿时代相同,析盐矿物组合类似.文章对比两者钾盐产出特征、成矿地质背景和成盐演化,分析两者成矿条件.建议在区域钾盐找矿工作中,应充分重视断陷盐盆地中有深卤补给的可能性,以及中、新生代碎屑岩系的盐盆地,如果成盐盆地规模较大,卤源补给丰富,古气候条件适宜,即使为陆源碎屑岩系,也仍有可能形成大型钾盐矿床.

“广西成矿规律及勘查部署研究汇总报告”是2010、2011年度广西大规模地质矿产勘查工程专题研究类“钦杭成矿带广西段整装勘查部署选区及成矿规律综合研究”项目、“南岭成矿带广西段整装勘查部署选区及成矿规律综合研究”项目和“广西地质找矿战略行动总体方案编制”项目下属“科技支撑”课题等成果报告的综合集成。该项成果是在广西国土资源专家田凤鸣领衔的专家组指导下，由中国地质科学院地质力学研究所韦昌山研究员带领相关研究群体历经四年多时间完成的。项目组通过总结主要类型矿床及成矿区带成矿规律，逐渐完善勘查区构造-蚀变调查方法，构建了预测区优选指标组合，提出整装勘查部署选区方案，评估与对比了各年度部署的勘查找矿成效，为修编广西找矿突破战略行动实施方案及2014年后续年度勘查工作部署提供了决策依据。

文章主要从找矿预测角度较系统梳理了我国常见的(金属)矿床类型,讨论了矿床类型与成矿地质作用和成矿地质体的关系.将我国主要成矿地质作用分为沉积地质作用、火山地质作用、侵入岩浆地质作用、变质地质作用、大型变形地质作用以及复合/叠加地质作用6类,并进一步划分出16个成矿地质作用亚类,共32种常见矿床类型.对每一类成矿地质作用和矿床类型的含义和特点进行了解释和说明.