地球物理探测是深部找矿预测不可或缺的重要手段,但是由于地质条件的复杂性及地球物理信息的多解性导致其地质解释的不确定性,需要通过多种途径加以限定.热电材料的电阻率和热导率具有明显的相关关系,但岩(矿)石的电阻率和热导率的关系鲜有研究.本文通过对前人岩(矿)石热导率和湖南岩(矿)石电阻率研究成果的梳理,发现岩(矿)石的热导率和电阻率具有明显的正相关趋势,认为这一规律有助于限定深部电阻率信息的地质解释.本文以湘南中生代钨锡多金属矿为例,初步探讨了岩(矿)石热导率和电阻率正相关趋势的深部找矿预测意义.

The Saxi tungsten-beryllium deposit is located in the Laojunshan tungsten-tin polymetallic metallogenic area in southeastern Yunnan. Determining the fluid nature, source, and evolution process of early layered orebodies and late vein-like orebodies and constraining their fluid geochemistry and isotopes can effectively explore the metallogenic mechanism of the Saxi tungsten-beryllium deposit, which is a collection of Laojunshan deposits. This study provides theoretical thinking for future prospecting work in the district. The formation of vein-like ore bodies in this deposit experienced a silicate stage, an oxide-sulfide stage, and a carbonate-fluorite stage. Scheelite and beryl were mainly formed in the first two stages. This article studies the fluid inclusions in quartz at different stages of the orebodies of the Saxi tungsten-beryllium deposit, including petrographic characteristics, microscopic temperature measurements, and laser Raman spectroscopy. The quartz sample's hydrogen-oxygen isotope composition in the ore-like ore body was tested. Three primary types of fluid inclusions (FIs) in vein-like ore bodies are detected, i.e.: liquid-rich FIs, gas-rich FIs, and aughter minerals bearing FIs. The gas phase composition of FIs is mainly H2O, with a small amount of reducing gas such as C2H2, and the liquid phase composition is also mainly H2O. From the silicate stage to the carbonate-fluorite stage, the peak homogenization temperature and salinity (NaCleq) of FIs are 240-360℃, 2.35%-13.81%; 220-310℃, 4.03%-9.86%, and 190-270℃, 2.41%-6.88%. From early to late, both homogenization temperature and salinity of the ore-forming fluid decreased obviously. The ore-forming fluid is generally a medium temperature, low salinity, CO2-poor NaCl-H2O fluid system. The δD and δ18O values of the quartz samples from early quasi-layered ore body are -102.8‰ to -99.0‰ and 11.7‰-13.0‰ respectively, and the corresponding δ18O value of the H2O value is 3.16‰-6.46‰. The δD and δ18O values of the quartz samplesfrom bulk oxide-sulfide section are -99.6‰ to -69.5‰ and 11.2‰-14.1‰ resoectively, and the corresponding δ18O value of H2O value is 3.08‰-6.73‰. This indicates that the ore-forming fluid mainly sourced from magmatic water mixed with a small amount of atmospheric precipitation or organic water.The fluid may boil, forming the precipitation of the main ore-forming minerals in the late vein-like ore body oxide-sulfide stage. The Saxi tungsten-beryllium deposit belong to a medium-to high-temperature hydrothermal system.

The Nanwenhe metamorphic dome contains a rare Silurian granitic pluton that developed in the SE Yangtze Block during early Palaeozoic orogenesis, and this pluton comprises the Nanwenhe gneissic granites. The petrogenetic and structural deformation histories of the gneissic granites recorded the multi-stage interaction of the SE Yangtze Block with other blocks during the Palaeozoic and Mesozoic, including the Cathaysia, Indochina, and Paleo-Pacific blocks. Zircon U–Pb and Hf isotopes and geochemical data indicate that the Early Palaeozoic granites (433–420 Ma) are S-type granitic rocks, and they were derived from the partial melting of ancient continental crust with no contribution from mantle material. And the large variations and positive values of εHf(t) (−12.25 to +10.69) of the gneissic granites are ascribed to a heterogeneous source and disequilibrium melting. Here we compare early Palaeozoic granitoids in the SE Yangtze Block (foreland belt) with those in the orogenic core, and suggest that the SE Yangtze Block underwent limited syn-collisional crustal thickening and metamorphism, and following which post-collisional granitoids were formed through partial melting of continental crust. Structural analysis of the Nanwenhe gneissic granites allows two stages of deformation to be identified: northward detachment (D1) and northwestward thrusting (D2). 40Ar–39Ar isotope dating of muscovites from the gneissic granites yields a well-defined plateau age of 229.61 Ma, which is interpreted as the timing of Late Triassic structural overprinting associated with the formation of the Nanwenhe metamorphic dome. Integration of our new results with previous research findings from the dome and South China allows us to conclude that the detachment deformation (D1) represents Late Triassic post-collisional extension, and D2 represented Jurassic intracontinental orogeny associated with subduction of the Paleo-Pacific Block.

The Furong tin deposit (South China) is genetically associated with the multiphase Qitianling batholith that consists of main-phase and minor, but more fractionated, late-phase granites. Several tourmaline and apatite generations are distinguished. Tourmaline (Tur) variants comprise pre-ore Tur-1 as disseminations and nodules in the late-phase granite, pre- to syn-ore Tur-2 as replacements in nodules and as veins crosscutting the late-phase granite and nodules, syn-ore Tur-3 in tin greisens, pre- to syn-ore Tur-4 as veins in the altered main-phase granite, and syn-ore Tur-5 from tin skarns in a distinct Ca-rich environment. Apatite (Ap) generations include accessory Ap-G in the main-phase granite, and Ap-I to Ap-III from three stages related to skarn-type mineralization (garnet-diopside stage-I, pargasite-phlogopite-cassiterite stage-II, and sulfide-rich stage-III). Textural and compositional features suggest that all tourmaline variants are hydrothermal in origin with alkali and schorl to foitite composition and minor extensions to calcic and X-site vacant tourmaline groups, whereas all apatite generations belong to fluorapatite with Ap-G crystallizing from the magma and Ap-I to Ap-III being hydrothermal in origin. The narrow range of tourmaline delta B-11 values (-14.8 to -10.4 & PTSTHOUSND;) suggests a single magmatic boron source in the ore-forming fluids. The similar rare earth element patterns and epsilon(Nd(t)) values (-8.2 to -5.9 for Ap-G and -8.0 to -7.3 for Ap-I) between magmatic and hydrothermal apatite indicate that the skarn-forming fluids are dominantly derived from granites. The Sr-87/Sr-86 ratios of Ap-I to Ap-III (0.70733-0.70795) are similar to the carbonate wall rocks, but distinctly diferent from the more radiogenic granites, indicating Sr exchange with carbonate rocks. Integrating previous H-O isotopic data, the tourmaline and apatite elemental and B-Sr-Nd isotope results suggest that the greisen-type ore formed by interaction of B-, Na-, Li-, Zn-, and Sn-rich magmatic fluids with the late-phase granite in a closed and reduced feldspar-destructive environment, whereas the tin skarns resulted from mixing of magmatic fluids with meteoric water and interaction with the carbonate wall rocks in an open system where oxygen fugacity changed from reduced to oxidized conditions. During fluid-rock interactions and fluid mixing, considerable Ca, Mg, V, Ni, and Sr from the host rocks were introduced into the ore system. Coupled hydrothermal minerals such as tourmaline and apatite have great potential to fingerprint the nature, source, and evolution of fluids in granite-related ore systems.

The altered granite-to skarn-type Furong tin deposit (530,000 t Sn @ 0.8% Sn) lies at the southern margin of the multiphase Qitianling granite batholith, South China. Chlorite alteration is a distinct feature at Furong, and four chlorite variants are identified: (i) chlorite partially or pseudomorphically replacing biotite in weakly chloritized granites (Chl-W), (ii) chlorite aggregates interlocking irregularly with quartz, cassiterite, and magnetite in intensely chloritized granites (tin ores) (Chl-I), (iii) comb-shaped chlorite in quartz veins crosscutting the intensely chloritized granite (Chl-V), and (iv) chlorite replacing garnet, diopside, and vesuvianite in skarns (Chl-S). Compositionally, all the Furong chlorite samples belong to trioctahedral Fe-chlorite (chamosite). Empirical chlorite geothermometry without Fe/(Fe + Mg) correction yielded formation temperatures of 321-422 degrees C and 397-420 degrees C for the granoblastic chlorite variants Chl-I and Chl-V, respectively, and lower temperatures of 273-343 degrees C and 285-366 degrees C for the pervasive chloritization variants of Chl-W and Chl-S, respectively. Chl-W is the result of layer-by-layer replacement with two biotite layers being converted to one Chl-W layer, and Chl-S formed by a dissolution-transport-precipitation mechanism. Both variants formed in a rock-dominated fluid environment, with their elemental compositions controlled dominantly by the precursor minerals and temperature. In contrast, Chl-I resulted from the dissolution-transport-precipitation process in a fluid-dominated system, and Chl-V precipitated directly from the fluid. During intense fluid-rock interaction, the fluid provided considerable Fe, Zn, and Sn to form granoblastic Chl-I and Chl-V together with cassiterite. Fluid flow was controlled by NNE-trending fault zones which were the preferential sites of mixing of ascending metal-rich magmatic fluid with meteoric water and fluid interaction with the granites.

Sediment-hosted Cu-Co deposits in the Zhongtiao Mountains are hosted by the metasedimentary rocks of the Paleoproterozoic Zhongtiao Group in the southern part of the trans-North China orogen, North China Craton. The ore genesis is still disputed with proposed genetic models including metamorphosed sedimentary exhalative (M-SEDEX), metamorphosed sediment-hosted stratiform copper (M-SSC) and metamorphogenic mineralization type. Pyrite occurs as a ubiquitous mineral throughout all ore-forming stages and is ideal for clarifying this issue via the integration of in situ (LA-ICP-MS and EPMA) elemental and LA-MC-ICP-MS sulfur isotope composition analyses. Two main types of pyrite are identified based on petrographic and SEM observations: fine-to medium-grained, variably deformed and inclusion-rich Py1 (including Py1a and Py1b subtypes) in the dissem-inated-veinlet mineralization stage (S1), and coarse-grained, fractured Py2 (including Py2a and Py2b subtypes) in the fracture-controlled vein-type mineralization stage (S2, main ore stage). Deformed and inclusion-rich Py1a is overgrown by inclusion-poor Py1b, and nonporous Py2a is rimed by porous Py2b. Geochemical results show that the studied pyrite samples have considerable contents of Co (mean > 1000 ppm) and Ni (mean > 100 ppm). These features could be related to both the Co and Ni-rich sedimentary environment (e.g., a volcaniclastic-rich sulfidic marine) and metamorphic enrichment. The content of Se (mean > 200 ppm) in Py2 is significantly higher than that in Py1, indicating the extensive interaction of mineralizing fluids with Se-bearing graphite schist. LA-ICP-MS mapping and textural studies indicate the presence of coupled dissolution-reprecipitation (CDR) reactions that could lead to trace metal compositions (e.g., Co, Ni, Se, Pb, Bi) in the product phases (Py1b, Py2b) that differ from those of their parent phases (Py1a, Py2a). These variations were most likely controlled by fluid temperature and precipitation of specific minerals. The grain-scale chemical zoning of Py2a revealed by elemental mapping indicates fluctuating fluid parameters (e.g., temperature, fS2, and/or parent fluid composi-tions). The bimodal distributions in Py1 (10-14 %o and 18-24 %o) are consistent with the inheritance of sulfur from sedimentary pyrite and the input of thermochemical sulfate reduction (TSR)-related sulfur from reworked evaporite sulfates in an increasingly open system. The relatively lighter and wider variation in 834S values (3.2-22.4 %o, mean = 15.1 %o) of Py2 implies that the evolution of the ore fluid in S2 was far more complicated, probably as a result of fluid-rock interactions and fluid cooling. During this process, hydrothermal rims with lighter 834S values (8.4 %o) grew on older metamorphic pyrite cores with relatively heavier 834S values (17.4-18.2 %o). Chalcopyrite displays overlapping S isotopic compositions with pyrite from different minerali-zation stages, suggesting that copper sulfides inherited reduced sulfur from earlier formed pyrite. Cooling and fluid-rock interactions serve as the critical controls triggering Cu precipitation from the fluid. The combined textural and compositional data of pyrite and chalcopyrite are suggestive of a syn-orogenic copper deposit model, in which all the ore-grade copper was introduced during the Zhongtiao orogeny.

It remains poorly constrained whether remobilization of Sn from granites and prograde skarns plays an essential role in forming economic (skarn-type) tin mineralization. Using both electron probe microanalysis and laser ablation-inductively coupled plasma-mass spectrometry methods, in-situ Sn contents, as well as major elements, were analyzed for numerous silicates and magnetite from fresh granite, altered granite, and skarn at the large Furong Sn deposit (530,000 t Sn @ 0.8% Sn) in the Nanling Range, South China. Hornblende and biotite in fresh granite are the main Sn-bearing phases (Sn = 44-321 ppm), while plagioclase and K-feldspar are poor in Sn (< 5 ppm). In altered granite, tin is hosted mainly by hydrothermal muscovite (299-583 ppm) replacing plagioclase, but rarely by chlorite (mostly <10 ppm) replacing hornblende and biotite. In contrast, most silicates (garnet, diopside, vesuvianite, pargasite and epidote) and magnetite from tin skarn are Sn-rich (47-44,241 ppm), except for Sn-poor phlogopite and scapolite (< 10 ppm). In particular, garnet, pargasite, and epidote reach tin concentrations in the percent range. Tin generally enters the stannous silicates and magnetite through substitutions for octahedral Al-vi and Fe3+. Comparisons of Sn contents between magmatic and hydrothermal minerals in granite, prograde and retrograde minerals related to tin skarn indicate that remobilization of Sn from granite and prograde skarn is not a pre-requisite to form tin mineralization.

"构造变形岩相"填图方法的创立和应用为老矿区深部及外围的找矿工作指明了方向,在实践中取得了显著的效果,需要大力推广和深入研究.对于构造变形岩相带的深部结构认识,需要依靠地球物理信息的解译.与地球物理场性质相类似,构造变形岩相带也是一个现存的地质体;物探工作目的 是要探测和揭示构造变形岩相带的埋深、轮廓、内部结构构造等特征,为确定其形成时间和演化过程提供依据.由于地质与地球物理的复杂时空关系,如果仅以新鲜岩石标本物性参数的差异作为判别标志,难以提高地球物理方法的分辨率和有效性.结合构造变形岩相进行综合解译,更能提高解释推断成果的多学科融合性.作为终极勘探目标,需要紧密结合构造控矿级序,建立构造变形岩相带的三级分类标准,提取对应的地球物理信息:一级构造变形岩相带为目标物所处的构造单元及构造应力场,及其所对应的区域地球物理场特征,如隆凹构造相间的伸展构造域;二级构造变形岩相带为目标物所处的控矿构造体系,及其所对应的矿田地球物理场特征,如岩浆核杂岩隆起-拆离构造系统;三级构造变形岩相带为目标物所在的有利成矿构造部位,及其所对应于关键剖面的地球物理特征,如侵入岩体与围岩的接触带或者含矿断裂带等.选择国际流行的典型金属矿床类型,介绍了三级构造变形岩相带的地球物理组合信息特征及其分级利用操作流程,为有效应用地球物理勘探方法开展深部找矿预测提供了范例.

篦子沟、南河沟铜矿床位于华北克拉通中部造山带南缘,是山西中条山地区胡篦型铜矿的典型代表,因严格受地层控制,呈层状、似层状产出,也被认为是沉积岩型层状铜矿床.这些矿床的成矿年龄仍未被精确测定,成矿时代长期存在争议.在矿床学研究的基础上,对篦子沟、南河沟铜矿内与矿化有关的蚀变黑云母开展了高精度的40 Ar-39 Ar测年.获得篦子沟铜矿床黑云母40Ar-39Ar坪年龄为1825±13 Ma(MSWD=8.86),对应的等时线年龄为1820±13Ma(MSWD=5.67),反等时线年龄为1820±13 Ma(MSWD=5.63);南河沟黑云母40Ar-39Ar坪年龄为1861±14 Ma(MSWD=8.17),对应的等时线年龄为1864±16 Ma(MSWD=8.31),反等时线年龄为1865±16 Ma(MSWD=8.47).2个矿床的成矿年龄在误差范围内一致,表明胡篦型铜矿热液期矿化年龄限定在1850 Ma左右.此年龄与中部造山带约1.85 Ga峰期变质和退变质作用时间一致,综合已有研究成果推测,该期成矿事件与碰撞造山事件耦合.区域上,在侵入中条群的基性岩内发育含矿石英脉,对脉内与硫化物伴生的白云母进行40 Ar-39 Ar定年,获得其坪年龄1851±13 Ma(MSWD=7.47),对应的等时线年龄为1844±19 Ma(MSWD=7.30),反等时线年龄为1844±19 Ma(MSWD=7.28),说明基性岩内的含矿石英脉与矿区内的热液期矿化为同一地质事件的产物,印证了碰撞造山过程中产生的变质流体广泛作用于区域各地质体,且影响范围广泛.

The Furong tin deposit (530,000 t Sn @ 0.8% Sn) is located in the southern part of the Mid-Late Jurassic, multiphase, granitic Qitianling batholith in the Nanling Range, South China. The spectrum of tin mineralization comprises skarn, chloritized granite, greisen, and quartz vein types, of which the skarn type is the most important. Cassiterite U-Pb dating provided Tera-Wasserburg lower intercept ages of 157.1 +/- 1.5 Ma and 156.3 +/- 1.5 Ma for skarn-type mineralization, 158.1 +/- 1.4 Ma and 158.7 +/- 1.6 Ma for chloritized granite-type mineralization, 155.8 +/- 3.4 Ma for greisen-type mineralization, and 160.1 +/- 1.7 Ma for quartz vein-type mineralization. These ages overlap with each other and define a pooled weighted mean age of 157.9 +/- 1.1 Ma (2 sigma) for the tin ore system. Hydrothermal phlogopite from tin skarn and muscovite from tin greisen yielded younger 40Ar-39Ar plateau ages of 154.3 +/- 1.9 Ma and 150.0 +/- 1.5 Ma, respectively, which may reflect resetting due to post-ore fluid circulation. Distinctive cathodoluminescence textures and trace-element patterns of various cassiterite types indicate that the four ore types resulted from pulsed ore-forming fluids and changes in temperature in a single magmatic-hydrothermal system. In combination with the geological characteristics, the geochronological and trace-elemental data of cassiterite indicate that the formation of different ore types at Furong was associated with the most fractionated and latest alkali-feldspar granite of the Qitianling batholith, and resulted from the specific interactions of the ore-forming fluids with their granite and limestone host rocks.

构造体系由多方向、多应力-应变性质和多重次序的结构构造组成,这些结构面在构造应力场中有较为固定的分布型式.经过区域成矿带、矿田、矿床等不同层次地质研究,揭示了新华夏构造体系的共轭剪切、挤压和引张三种类型结构面,它们在平面上组成"米字型"构造.通过应力-应变有限元法模拟,将"米字型"构造分为三个形成阶段:第一期共轭构造阶段,发育NNW 345°方向(大义山式)张扭断裂和NEE 75°方向(泰山式)压扭构造;第二期挤压构造阶段,产生NNE 25°方向挤压断裂和褶皱;第三期横张构造阶段,产生NWW300°方向(长江式)的横张断裂,给出了有利于控矿成矿的应力-应变场特征,为地质找矿指明了方向.三个阶段相比,构造带内主干拉应力以第一期NNW向构造带内为最大,第三期NWW向"长江式"构造带次之,第二期NNE向和第一期NEE向构造带内拉应力微弱,拉应力总体呈现出时间由老到新从最高下降至微弱之后再回升的趋势;最大主压应力从第一期NEE向构造带为中等,演进到第二期NNE向构造带为最大,第三期NWW向"长江式"构造带和NNW向构造带为最小,表现出时间由老到新,先增强至最高值再下降至最小的趋势.

构造体系由强变形构造带和弱变形地域共同构成,这些构造带和变形带可以用结构面的形式表达.构造体系结构面的分布分析,更加适用于变形规律研究,便于追索构造应力场及其演化.以长江中下游地质结构与导矿-控矿要素研究为基础,总结了新华夏构造体系结构面的"米字型"分布特征.新华夏系"米字型"构造,由NNE 25°方向挤压断裂和褶皱带、NNW 345°方向(大义山式)张扭断裂、NEE 75°方向(泰山式)压扭构造和NWW 300°方向(长江式)的横张构造组成.其演化分先后三个阶段;NNW 345°方向—NEE 75°方向的共轭剪切构造阶段、NNE 25°方向挤压构造阶段和NWW 300°方向的张性剪切构造阶段.新华夏构造体系的"米字型"构造样式的识别,为研究构造体系的应力-应变成因、探讨构造体系的形成演化以及浅部构造和深部构造相关性研究提供了重要的地质构造基础.在其它类型的构造体系中,结构面也具有"米字型"分布特征.

华南大陆中生代以来受华北板块、 西南缘特提斯洋以及东部古太平洋板块会聚作用形成了多序次的构造变形及多期岩浆与成矿事件,并造就了多个重要的多金属成矿区带.文章在梳理成矿区带典型矽卡岩型矿床矿化期次、 矿体分布及成矿机理等关键科学问题的基础上,利用构造变形序次及其控岩控矿的规律性完善了典型矿床成矿过程及成因机理.通过对闽西南铁多金属成矿带、 赣东北塔前-赋春钨铜多金属成矿带以及滇东南老君山钨锡矿集区开展构造变形解析,结合已有研究成果,厘定出相对完整的印支期、 中晚侏罗世及白垩纪3期变形序列,但其作用时限、 构造性质、 规模强度及变形样式却表现不一.通过构造控岩分析并结合已有同位素年代学得出,不同成矿区带都存在与变形序列相一致的岩浆或变质热事件,进而利用变形序列与岩浆期次对应规律明确了与马坑式铁多金属矿床、 朱溪钨铜矿床以及南秧田钨矿床相关的多期岩浆活动.在此基础上识别出多阶段矿化事件并提出3个典型矿床都存在多期叠加复合成矿的认识.从构造对矿床就位机制控制的角度分析了马坑式矿床分散多变矿体、 朱溪矿床垂向大跨度矿化及深部巨型矿体、 南秧田矿床层-脉叠加矿体分别受赋矿地层褶皱拆离、 大规模双重逆冲以及2期构造变形复合控制的机理.文章最后探讨了不同阶段华南重要成矿区带构造变形及岩浆成矿的动力学背景.

High-silica granites (> 74 wt% SiO2) in the Nanling Range are associated with important W-Sn deposits. Their petrogenesis remains controversial. The Qitianling composite pluton, one of the Mid-Late Jurassic W-Sn-related granitic plutons in the Nanling Range, comprises dominantly the main-phase medium- to coarse-grained K-feldspar megacrystic hornblende biotite monzogranites and biotite monzogranites (mostly < 70 wt% SiO2) in the outer zone, and minor fine-grained alkali-feldspar granites (high-silica granites with similar to 75 wt% SiO2) in the inner zone. SHRIMP zircon U-Pb dating indicates that the high-silica granites were emplaced at 154- 155 Ma, coeval with the main-phase granites (163-153 Ma) within the analytical error uncertainty. The whole- rock Nd (epsilon(Nd(t)) = -6.85 to - 6.56) and zircon Hf-O (epsilon(Hf(t)) = -12.2 to -2.2 and delta O-18(VSMOW) = 7.15 parts per thousand to 9.19 parts per thousand) isotopic compositions of the high-silica granites are indistinguishable from those of the main-phase granites, implying that they are derived from the same sources. Petrographic, mineralogical and geochemical data indicate that both granite types have A2-type affinity, with the high-silica variant characterized by more evolved chemical compositions, higher Rb/Sr, lower Nb/Ta and Zr/Hf ratios, more F enrichment, and more distinct REE tetrads. Based on the geochemical data, trace element modeling and recent studies on the fractionation processes in silicic magma system, we propose that the Qitianling granites have undergone a high degree differentiation in a crystal mush system. The high-silica granites represent the highly-fractionated interstitial melt that was extracted from the crystal mush system, whereas the main-phase granites represent the residual crystal mush consisting of the 'cumulate crystals' and trapped interstitial melt. The extraction is inferred to have occurred when the crystallinity of the mush reached about 67-76%, at least for the most evolved sample of the high- silica granites, and the residual crystal mush might have trapped about 15-25% interstitial melt. The highly-fractionated high-silica granites with high melting temperature and low oxygen fugacity are responsible for the greisen-type tin mineralization at the Furong tin deposit. (C) 2020 Elsevier B.V. All rights reserved.

华北克拉通北缘大规模金成矿作用集中发生在印支期和燕山期,有关更早期的金成矿作用研究较少.柴胡栏子金矿是赤峰-朝阳金矿集区西部典型的热液型金矿床,为探讨其成矿时代,本文对矿区内与矿体时空关系密切的中性脉岩进行了LA-ICP-MS锆石U-Pb同位素定年,得到矿区成矿前闪长玢岩的年龄为(332.4±1.7)Ma,成矿后闪长玢岩的年龄为(257.1±1.6)Ma,闪长岩脉的年龄为(266.1±0.6)Ma.结合前人所测矿区截断矿体的闪长玢岩年龄(290.9±4.3)Ma,将柴胡栏子金矿的成矿时代限定在(332.0±1.7)～(290.9±4.3)Ma,金矿化发生在中石炭世-早二叠世,是华北克拉通北缘少见的晚古生代金成矿事件,推测该金矿的形成与华北克拉通北缘陆-弧碰撞后构造体制由挤压向拉张的环境转换有关.

柴胡栏子金矿位于中国东部大兴安岭北北东向构造带与华北地块北缘近东西向构造带的交汇部位.该交汇区经历了多期构造-岩浆活动,产出了柴胡栏子、莲花山、红花沟等多个大-中型金矿床.航磁和遥感资料解译结果表明,矿田内发育北北西向、北西西向、北北东向和北东东向共4个方向的构造形迹,呈现"米字型"结构的展布特点,分别控制了晚古生代岩浆岩(脉岩)和主要金矿床的展布.在柴胡栏子金矿区,4个方向的构造形迹也组成了"米字型"结构,控制了矿体(矿化带)和化探异常的展布.矿田和矿区级别的构造形迹均呈现"米字型"分布特点,是新华夏构造体系分级控岩控矿规律的具体表现.上述认识为矿床成因研究和矿田成矿预测提供了重要的依据.

Southeastern (SE) Yunnan contains one of the most economically important Mesozoic W-Sn metallogenic belts in South China. The belt comprises three well-known W-Sn ore-concentration areas, namely, the Gejiu, Bainiuchang, and Laojunshan areas from west to east. Numerous skarn W-Sn deposits have been identified in association with Late Cretaceous granites in these areas, although the genesis and geodynamics of the deposits remain uncertain. The Nanyangtian W deposit, which is located in the southern part of Youjiang Basin and the eastern margin of the Laojunshan granitic pluton, consists of skarn and superimposed scheelite-mica-quartz (SMQ) vein mineralization. Multiple stages of structural deformation and mineralization, and geochronological data indicate the Nanyangtian deposit contains important clues to the genesis and geodynamics of W mineralization in SE Yunnan. Structural analysis of the Song Chay dome allows four stages of deformation to be identified from early to late, namely, north-directed detachment (D1), northwest-directed thrusting (D2), dextral transtensional faulting (D3), and late sinistral strike-slip faulting (D4). Laser ablation-inductively coupled plasma-mass spectrometry U-Pb dating of zircons from plagio-amphibolite and altered granitoid yielded ages of 220.37 +/- 0.59 and 162.5 +/- 3.0 Ma, respectively, indicating the timings of regional detachment deformation (D1) with related metamorphism, and the emplacement of coeval granite related to skarn W mineralization, respectively. 40Ar-39Ar isotope dating of muscovites from Laochengpo gneissic granite yielded well-defined plateau ages of 224.12 +/- 0.35 and 141.2 +/- 0.2 Ma, indicating the timing of D1 deformation and Early Cretaceous tectono-thermal event, respectively. 40Ar-39Ar isotope dating of biotite from an SMQ vein within the deposit yielded a well-defined plateau age of 97.81 +/- 0.70 Ma, which is interpreted to represent the timing of SMQ vein W mineralization. 834S values of sulfide in skarn ores range from 7.46%o to 9.55%o, and 818O values of skarn-type scheelite vary from 2.9%o to 4.0%o. However, 818O values obtained for vein-type scheelite range between 4.4%o and 5.7%o, indicating a different material source of W mineralization from that of the skarn ores. Based on our analysis of ore-controlling structures, isotopes, and geochronology, we propose that the inter-layer fractures that formed during D2 controlled the Late Jurassic skarn mineralization and associated granitic magmatism, and that Late Cretaceous SMQ vein mineralization resulted from dextral transtension (D3). Integration of the sequence of deformation and the two periods of W mineralization in combination with well-defined geochronological constraints indicates four stages of tectonism and mineralization in SE Yunnan: Late Triassic-Early Jurassic D1 deformation and early Sn mineralization, late Early-Late Jurassic D2 deformation and subsequent skarn mineralization and associated granitic magmatism, Cretaceous D3 deformation and associated W and late Sn polymetallic mineralization within a regional extensional setting, and Cenozoic postmineralization strike-slip D4 deformation. By combining our new results with other research findings from SE Yunnan and South China, the inferred sequence suggests that the multiple stages of deformation and mineralization were influenced by geodynamic processes involving the Indochina and Paleo-Pacific Plates with the South China Block.

Since the Mesozoic, the convergence of the Tethys ocean plate and the Paleo-Pacific plate on the South China block has resulted in the multi-sequence tectonic deformation as well as the multi-stage magmatic and metallogenic events, and has formed many important polymetallic metallogenic belts in South China. In this context, mineralization stages, distribution of ore bodies and metallogenic mechanisms of typical skarn deposits in metallogenic areas were sorted out. And then the mineralization processes and genetic mechanisms of typical deposits are completed using the sequence of tectonic deformation and its rock/ore-control regularity. A structural deformation analysis was made on the southwestern Fe polymetallic metallogenic belt, the northeastern Jiangxi Taqian-fuchun W-Cu metallogenic belt and the Laojunshan W-Sn ore concentration area to set up three relatively complete periods of deformation sequence during the Indosinian period, the middle-late Jurassic and the Cretaceous, combined with previous research results; however, the three deformation sequences differ in duration of tectonics, structural property, scale and strength, and deformation style. The analysis of rock-control by tectonics together with the existing isotope chronology data both revealed that the magmatic or metamorphic thermal events were consistent with the deformation sequence occurred in each mineralization zone, and then the multi-stage magmatic events related to the Makeng-type Fe polymetallic deposit, the Zhuxi W-Cu deposit and the Nanyangtian W deposit were clarified using the corresponding laws between deformation sequence and magmatic stage. On this basis, we identified the multi-stage mineralization events and supposed that multi-stage superposition occurred in the mineralization process of all three typical deposits. From the point of view of structural control over the emplacement mechanism of the ore deposit, this paper analyzed the mechanism of the decentralized polymorphic orebody of the Makeng-type deposit, the vertical large-span mineralization and deep giant orebody of the Zhuxi deposit, and the stratiform-vein superposition orebody of the Nanyangtian deposit, which are controlled by the folding detachment of the ore-bearing strata, the large-scale thrust duplex and the two-stage tectonic compounding respectively. The dynamic background of tectonic deformation and magmatic mineralization in the important metallogenic belts of South China at different stages were discussed.

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 Luanling gold telluride deposit in the Xiong'ershan region is located in the southern margin of the North China Craton. The deposit formed in four stages, that is, an early pyrite-quartz stage (I), a pyrite-molybdenite stage (II), a sulfide-telluride-gold stage (III), and a late carbonate stage (IV). Six species of telluride in stage (III) are recognized, including hessite, altaite, petzite, unidentified Au-Ag-Te mineral, empressite, and unidentified Ag-Te-S mineral. Gold occurs mostly as native gold and electrum along the microfractures of sulfides or the contact between sulfide and telluride. The mineralization temperature of stage I and stage III ranges from 296 to 377 degrees C and 241 to 324 degrees C, respectively. Tellurides in stage III precipitate at the log integral(S2) from -14.3 to -7.3 and log integral(Te2) from -17.4 to -9.4. The ores were formed in an oxidizing environment. The Re-Os model ages of molybdenite are 162-164 Ma, which indicate that the main ore formation stage was in the Late Jurassic. The Re contents of five molybdenite samples from the Luanling deposit have a range of 36.32-81.95 ppm, except for one large value of 220 ppm, which indicates that the ore-forming materials are mainly derived from a crustal-dominated source. The delta S-34 values of sulfides range from -17.6 to -6.2 parts per thousand, whereas those of sulfates are from 6.8 to 11.5 parts per thousand. The delta S-34( n-ary sumation S) value of the ore-forming system is 0.0-3.7 parts per thousand, indicating that the sulfur of the Luanling deposit derived from a deep igneous source. Mineral association and isotope data of the Luanling deposit, together with its geodynamic setting, imply that this deposit belongs to a part of the metallogenic system of the Nannihu-Sandaozhuang, Shangfangou porphyry molybdenum deposits, and the Late Jurassic granitic intrusions.