新疆东天山东戈壁钼矿床辉钼矿的矿物学特征及地质意义

东戈壁钼矿处于东天山-北山成矿带的西部,是该地区三叠纪钼成矿带代表性矿床之一。该矿床赋存于石炭系干墩组一套浅变质碎屑岩中,隐伏于矿体下部的花岗斑岩为其成矿岩体。本文对钼矿和成矿岩体进行了地质特征、岩相学和辉钼矿的显微构造和粉晶衍射等分析,结果显示矿石可分为黄铁矿-石英脉型和黄铜矿-黄铁矿-石英细脉型辉钼矿矿石,这两种类型矿石中的辉钼矿均为2H型。辉钼矿较大变化范围的Re含量主要受成矿流体Re含量控制,与晶形关系不大。综合分析认为形成于三叠纪的东戈壁钼矿床是东天山-北山地区后碰撞背景下岩浆热液作用的产物。     

东秦岭两种新型钼矿床的矿物特征及成因分析

东秦岭地区发现了两种新型的钼矿床——花岗岩型钼矿床和石英脉状钼矿床。花岗岩型钼矿床矿体赋存于花岗岩中,石英脉型钼矿与石英脉关系密切,矿体分布在石英脉的上下部流纹岩中,前者成矿与燕山期花岗岩热液有关,而后者是否是燕山期花岗岩热液的产物还有待进一步研究。两种类型钼矿床中的辉钼矿与石墨关系密切。     

胶东邢家山大型钼矿地质地球化学特征及成因意义

邢家山钼矿床是胶东唯一达大型规模的矽卡岩型钼(钨)矿,本文在详细野外调研的基础上,划分了成矿期次,通过元素地球化学及同位素地球化学示踪成矿物质来源及形成时代并结合区域成矿背景探讨了成矿机制。该矿床成矿过程可划分为岩浆热液期(包括早期矽卡岩阶段、中期硫化物阶段和晚期碳酸盐岩阶段)和表生氧化期,钼矿化主要发生于中期硫化物阶段,辉钼矿主要赋存于石榴石透辉石矽卡岩和透辉石符山石矽卡岩中,为岩浆热液交代作用过程产物。成矿母岩幸福山岩体中SiO2、Al2O3和Fe2O3等物质迁出,为矽卡岩矿物形成提供了丰富的物源,矽卡岩和花岗岩的稀土和微量元素配分相似,显示二者具有成因关系,稀土明显富集LREE;钼矿化矽卡岩中δEu、δCe的变化较小,离矿区较远的铅锌矿化大理岩中δEu显示较小的负异常、δCe显示较弱正异常。C-O同位素测试数据显示,大理岩中C来源于海相碳酸盐岩,而热液方解石脉中C主要来源于岩浆岩;辉钼矿中Re含量较低指示着成矿物质来源于下地壳。该矿属于形成于燕山早期的岩浆接触交代矽卡岩型钼矿床。     

河南省石门沟钼矿床地质特征及成因探讨

石门沟钼矿辉钼矿（化）特征为燕山晚期由基性岩浆底侵作用而形成的二长花岗岩体和地表出露的的厚大石英脉体全岩含矿。分析了河南西峡县石门沟钼矿成因机理与成矿模式。认为石门沟辉钼矿化二长花岗岩是下地壳物质部分熔融作用形成的富含Mo元素的花岗质岩浆,由基性向酸性正向演化,后经岩浆结晶分异、同化混染作用,钼（钨）等金属矿物以熔离状态分布在岩浆矿房中;岩浆热液沿构造薄弱带上升到地壳浅部后,富水热流体分离,进入气成热液阶段,形成高中温纵横交错含钼脉体或含钼花岗岩体。石门沟钼矿成因类型为岩浆型、热液充填石英脉型辉钼矿床,与斑岩型有明显区别。     

广西油麻坡钨钼矿床地球化学特征及成因探讨

文章总结了广西油麻坡钨钼矿床地质特征,将矿床的矿化类型大致划分为矽卡岩型白钨矿和石英脉型辉钼矿,两者是同一含矿热液不同阶段演化的产物,前者主要产在接触带的矽卡岩中,后者的产出不受岩性控制,多以网脉状充填在围岩裂隙中,并可见少量石英脉型辉钼矿体叠加在早期形成的矽卡岩型白钨矿体之上。本次研究对代表性钨钼矿石样品进行了C、H、O、S同位素测定,并对石英脉型辉钼矿矿石内的石英进行了包裹体的测定,结合油麻坡花岗闪长斑岩体的岩石学、矿物学及地球化学特征,认为成矿流体及矿质起初主要来源于斑岩体,在岩体上侵过程中,可能萃取了部分古生代地层中的成矿物质,热液演化后期伴随有大气降水的加入,使得成矿流体具有混源特征,流体体现为岩浆期后中高温_低盐度体系。     

西秦岭温泉斑岩钼矿床岩浆-热液演化

西秦岭北缘广泛出露印支期中酸性侵入岩和相关的斑岩-矽卡岩矿床。温泉矿床位于该矿带东段,是其内已探明规模最大的斑岩钼矿床。温泉矿床发育多阶段热液脉体,黄铁矿作为其中的贯通性金属硫化物,其化学组成蕴含着岩浆-热液演化及金属沉淀过程等诸多信息,对于斑岩系统模型的厘定具有重要意义。温泉矿床热液脉体时序为:钾长石-黑云母-石英脉(A脉)、石英-黄铜矿脉、石英-辉钼矿脉(B脉)和石英-绢云母-黄铁矿脉(D脉)。A脉是斑岩系统岩浆-热液演化的最早期脉体,主要矿物组合为钾长石+黑云母+石英+黄铁矿±磁铁矿±磷灰石±黄铜矿,代表了引起早期基性岩浆矿物被蚀变为黑云母的流体通道;B脉与钾长石化蚀变关系密切,围岩中斜长石斑晶大量被蚀变为钾长石;石英-辉钼矿脉切割所有早期黑云母化-钾化蚀变阶段的石英-硫化物网脉,并形成于所有斑岩侵位之后,少量黄铁矿和黄铜矿共生于辉钼矿裂隙及边部;D脉是斑岩系统岩浆-热液成矿作用的最晚期事件,其主要被黄铁矿和石英及少量黄铜矿填充,发育晚期的绢英岩化和泥化蚀变,长石多发生破坏性蚀变。四个阶段石英网脉中黄铁矿电子探针分析显示,A脉的黄铁矿中Cu、Mo和Au含量均较低,有少量的金属硫化物(黄铁矿+黄铜矿)沉淀,但通常不能形成规模矿体;石英-黄铜矿脉的黄铁矿中Cu含量明显较高,且多与高品位Cu矿体的空间产出位置相一致,可能是斑岩系统伴随钾化蚀变作用主要的铜沉淀阶段;B脉的黄铁矿中Mo含量明显较高,与高品位钼矿体空间产出关系密切,可能代表了斑岩系统钼成矿作用的主要阶段;D脉的黄铁矿中Au含量明显升高,可能代表了金在斑岩系统岩浆-热液成矿作用的最晚期事件中的沉淀。     

中国东部中生代钼矿成岩-成矿时差

与岩浆成因相关的钼矿床成岩-成矿时差是确定矿床与岩浆岩成因关系的重要基础.本文根据收集的中国东部中生代典型钼矿床的成矿及相关岩体的同位素测年数据,详细讨论并定量厘定了钼矿的成岩-成矿时差分布特征.结果表明,钼矿成矿同步或略滞后于同源岩浆活动,中国东部整个钼矿成矿高峰的两个阶段时差介于0～10.0 Ma和0～15.0 Ma;对于单个钼矿床,其成岩-成矿时差集中在0～14.0 Ma,均值为3.9 Ma;从斑岩型钼矿床→斑岩-矽卡岩型钼矿床→矽卡岩型钼矿床→石英脉型钼矿床,成岩-成矿时差呈逐渐增加趋势,这与岩浆热液成矿过程的地质事实吻合.     

河南省嵩县某钼矿床地质特征及找矿方向研究

通过对某区矿床的地质特征分析认为,鸡蛋坪组上段流纹斑岩地层对钼成矿具明显层控作用;顺层缓倾斜产出的石英脉(细脉)和蚀变岩是区内主要含矿层位;长时间、多期次的岩浆热液活动,为区内钼矿的形成提供了热动力和部分矿物质。矿区矿物组合主要为:黄铁矿-方铅矿-辉钼矿组合,脉石矿物主要为石英、长石。矿区矿石结构、构造较复杂;矿石矿物成分较简单,但伴生元素种类较多;矿脉围岩蚀变主要局限于矿脉的两侧,近似对称产出,呈现脉型矿床所独有的线性蚀变特征,与钼矿化有关的蚀变主要有钾长石化、硅化等;局部具有萤石化、碳酸盐化。矿体与围岩界线渐变过渡,具热液充填矿床的特点。矿床成因为受地层层间裂隙控制的的中、低温热液充填型层状钼矿床。     

河南省栾川县三道庄钼钨矿床地质和流体包裹体研究

河南省栾川县三道庄钼钨矿床是东秦岭钼矿带的5个超大型钼矿床之一,产于华北克拉通南缘,形成于燕山期碰撞造山体制的后碰撞构造环境.矿体定位于燕山期花岗斑岩与栾川群浅变质碎屑岩-碳酸盐建造的外接触带,矿石构造主要是浸染状和网脉状,广泛发育长英质脉、辉钼矿脉、石英.辉钼矿脉、石英-黄铁矿脉、碳酸盐-萤石脉等.围岩蚀变类型复杂,主要有矽卡岩化、钾化、硅化、绿帘石化、绿泥石化、绢云母化、碳酸盐化、萤石化以及黄铁矿化、辉钼矿化等硫化物化,矿石类型主要是矽卡岩型和角岩型,属于典型矽卡岩型钼钨矿床.成矿过程分为矽卡岩阶段(早)、石英-硫化物阶段(中)和石英-碳酸盐(晚)3个阶段.流体包裹体有CO_2-H_2O、H_2O-NaCl和含子晶包裹体等3种类型,早阶段主要发育CO_2-H_2O和含子晶包裹体,晚阶段只见H_2O-NaCl包裹体,中阶段发育3类包裹体;早、中、晚3个阶段流体包裹体均一温度分别为394～552℃、290～410℃和140～290℃,盐度分别为20.60 wt%～67.18 wt% NaCl.eqv、6.30 wt%～48.55 wt%NaCl.eqv和3.39 wt%～11.46wt% NaCl.eqv.早阶段流体具有高温、高盐度、富含CO_2的岩浆热液特征,晚阶段流体以低温、低盐度、贫CO_2为特征,中阶段流体沸腾作用强烈,是成矿物质快速沉淀的重要机制.成矿系统由静岩压力向静水压力体系转变,趋于开放.     

陕西华县西沟钼矿地质、地球化学特征及其对矿床成因的制约

为了研究西沟钼矿床的成矿物质来源及矿床成因,对西沟钼矿床进行了地质、地球化学及稳定同位素研究。结果表明,西沟钼矿床的矿体主要以石英-方解石脉、石英脉类分布于太华岩群内,少量长石-石英脉型,辉钼矿、方铅矿、黄铁矿是主要矿石矿物,方解石和石英是主要的脉石矿物;含矿方解石具有较高的Sr、Ba和稀土含量,稀土元素及其特征值具火成碳酸岩组分特征,与黄龙铺矿田碳酸岩脉型钼矿床相似;成矿物质和成矿流体主要来源于深源或上地幔,成矿过程中有少量壳源物质或地下水参与。研究认为西沟矿床为石英-碳酸岩脉型钼铅矿床。     

Re-Os Dating of Molybdenite from the Yaogangxian Tungsten Deposit, South China, and Its Geological Significance

The Yaogangxian tungsten deposit is located in the central part of the Nanling polymetailic metallogenic province. The orebodies occur as veins. Wolframite and molybdenite are the dominant ore minerals. Two samples were selected for molybdenite Re-Os dating in order to elucidate the timing of mineralization. Re-Os datings of molybdenite from quartz-woiframite veins and disseminated in granite yield ages of 153±7 Ma and 163.2±4.2 Ma respectively. The results indicate that the Yaogangxian tungsten deposit is the product of large-scale metallogenesis in the middle Yanshanian period in South China, and that the evolution from late magmatic to postmagmatic hypothermal mineralization occurred at about 10 Ma. The rhenium content of molybdenite in the Yaogangxian tungsten deposit suggests that the ore materials originated from the crust.     

赣南樟东坑钨矿两类矿化中辉钼矿的Re-Os同位素定年及其地质意义

赣南樟东坑钨矿具有典型的"上脉(黑钨矿石英脉)下体(蚀变细粒花岗岩)"和"上钨下钼"矿化模式, 为了弄清黑钨矿石英脉与蚀变细粒岩体型矿化之间在成矿时间上的关系, 对产于该矿细粒花岗岩中的辉钼矿和石英脉中的辉钼矿分别进行了Re-Os同位素定年. 测试结果为: 细粒花岗岩中的3件辉钼矿样品Re-Os等时线年龄为155.4±2.1 Ma(MSWD=1.12), 模式年龄154.9±2.6 Ma~156.5 ± 2.6 Ma, 加权平均年龄155.5±1.4 Ma(MSWD=0.44);而石英脉中5件辉钼矿样品的Re-Os等时线年龄为154.6±1.7 Ma(MSWD=0.030), 模式年龄变化范围为154.2±2.3 Ma~154.7±2.7 Ma, 加权平均年龄为154.29±0.98 Ma(MSWD=0.045). 上述结果表明, 花岗岩体型矿化与石英脉型矿化的年龄在误差范围内高度一致, 从而证明了岩体中的钼钨矿化与石英脉中的钨钼矿化为同一次岩浆热液矿化事件的产物.      

河北东坪碲金矿床辉钼矿Re-Os及锆石U-Pb年龄研究

东坪碲金矿床是与碱性侵入岩有关的国内规模最大的碲金矿床。虽然前人已对该矿床做过大量研究,但其成矿年龄仍存在较大争议。文章通过对矿床中辉钼矿Re-Os和锆石U-Pb年龄进行研究,对成矿年龄和矿床成因进行限定。矿床中的辉钼矿存在浸染状和细脉状两种产状。浸染状辉钼矿通常产于正长岩,与硫化物共生,Re-Os模式年龄为(401.1±2.1)和(402.8±2.1) Ma。细脉状辉钼矿主要产在石英-硫化物脉中,其内部及裂隙中产出大量自然金,Re-Os模式年龄为(380.3±2.0)和(376.9±2.9) Ma。含金石英脉中的岩浆锆石U-Pb年龄为(394±1.7) Ma,热液锆石U-Pb年龄为(382±4.7) Ma。辉钼矿与锆石年龄一致,且与水泉沟碱性杂岩体侵位年龄相吻合,因此认为东坪碲金矿床存在泥盆纪成矿,可能与水泉沟岩体岩浆活动有关。矿床经历了晚侏罗世—早白垩世岩浆流体的交代、活化、富集过程,最终形成大型碲金矿床。矿床中的碲主要来自上地幔或洋壳物质的部分熔融,水泉沟碱性岩浆出溶的高氧逸度、中偏碱性的流体和脱气作用为碲的迁移和富集提供了重要条件。     

Geology and Metallogeny of the Shizhuyuan Skarn-Greisen Deposit,Hunan Province,China

The Shizhuyuan deposit is the largest among the economically important polymetallic tungsten deposits in China. The deposit occurs within the thermal aureole of Yanshanian felsic intrusions that were emplaced into Devonian carbonates and marls. The mineralization can be divided into three phases that are genetically associated with three episodes of granitic emplacement-pseudoporphyritic biotite granite, equigranular biotite granite, and granite porphyry. During the emplacement of pseudoporphyritic biotite granite, thermal metamorphism and subsequent skarnization developed around the stock. The pure limestone was transformed to marble, whereas marls and argillite interlayers were changed to a series of metamorphic rocks such as grossular-diopside hornfels, wollastonite hornfels, diopside hornfels, wollastonite-vesuvianite hornfels, muscovite-K-feldspar-anorthite hornfels, and prehnitevermiculite hornfels. Because of the subsequent strong skarn development, most hornfelses later were transformed into skarns. The skarns distributed around the granite stock are mainly calcic. They are massive in structure, and are composed mainly of garnet, pyroxene, vesuvianite, and wollastonite, with interstitial fluorite, scheelite, and bismuthinite. Although there is no cassiterite in the early skarns, their tin contents average 0.1%. The distribution and compositional and mineralogical relationships of skarn minerals suggest that they formed as a result of progressive reactions of a hydrothermal solution with a limestone of generally constant composition, and that the dominant process was progressive removal of Ca and addition of other constituents to the rocks.

Following the primary skarn formation, some of the assemblages were retrograded to new assemblages such as fluorite-magnetite-salite rock, magnetite-fluorite-amphibole rock, and magnetite-fluorite-chlorite rock. The retrograde alteration of the skarns is characterized by a progressive addition of fluorine, alkali components, silica, tin, tungsten, and bismuth. A zonation from garnet-pyroxene skarn or garnet skarn, through fluorite-magnetite-salite rock, to magnetite-fluorite-chlorite rock frequently can be recognized in the deposit. All retrograde-altered rocks contain scheelite, cassiterite, molybdenite, and bismuthinite.

During the emplacement of equigranular biotite granite, skarn veins several tens of centimeters wide were developed; they contain large crystals of garnet and vesuvianite, and interstitial scheelite, wolframite, cassiterite, and molybdenite. This second stage of mineralization occurs predominantly as coarse and fine stockwork greisens, which were superimposed on the massive skarns and surrounding marble. Such W-Sn-Mo-Bi-bearing greisens can be divided into topaz greisen, protolithionite greisen, muscovite greisen, and margarite greisen. Besides calcic skarn veins and greisens, manganese skarn veinlets also were developed; they consist of rhodonite, spessartine-almandine solid solution, spessartine, and helvite. The distribution of greisens is responsible for a metal zonation—i.e., W-Sn-Mo-Bi and Sn-Be-Cu-F zones from the contact boundary between the granite stock and skarns outward in the deposit. A third stage of mineralization is represented by lead-zinc veins, which also are accompanied by manganese skarns consisting of spessartine, rhodonite, manganese-rich pyroxene, helvite, tephroite, fluorite, tourmaline, and manganese-rich phlogopite.     

新疆东天山小白石头钨(钼)矿辉钼矿Re-Os同位素年龄及成矿时代

小白石头钨(钼)矿床位于新疆东天山造山带中的中天山地块南缘,该矿床是一个由黑云母花岗岩和花岗闪长岩侵入中元古界卡瓦布拉格群形成的矽卡岩型钨(钼)矿床。辉钼矿作为其主要的矿石矿物之一,呈不同产出状态分布于花岗闪长岩、黑云母花岗岩、矽卡岩和石英脉中。目前,对于小白石头钨(钼)矿成矿时代尚有争议,特别是与花岗闪长岩有关的辉钼矿化形成时代缺乏精确的限定。本文选取与花岗闪长岩有关的不同产状辉钼矿进行Re-Os同位素定年,获得Re-Os加权平均模式年龄为245. 0±1. 7Ma,Re-Os等时线年龄为245. 5±4. 3Ma。准确的Re-Os同位素定年限定小白石头钨(钼)矿床的成矿年龄和花岗闪长岩的侵位年龄为245Ma左右,为矿床模型建立和找矿方向确定提供了关键依据,同时也为东天山区域成矿规律总结提供了重要的年代学证据,并指出新疆东天山—甘肃北山地区存在一条找矿潜力巨大的三叠纪钨钼成矿带。     

Re-Os Geochronology of Molybdenite from Yuanzhuding Porphyry Cu-Mo Deposit in South China

The Yuanzhuding porphyry Cu-Mo deposit, discovered in 2008, is located within the southern segment of the Chenzhou-Huaiji fault belt, South China. The deposit is hosted within the Upper Cambrian neritic facies sandstone and shale formation that is the strata of the axis and wings of within the Yuanzhuding anticline. Both of the porphyry and exo-contact zone contain Cu-Mo mineralization. Economic orebodies occur mainly in the exo-contact zone around the porphyry. We dated 11 molybdenite samples obtained from two borehole cores of the deposit, using the Re-Os method. Analyses of eight molybdenite samples from borehole ZK12-112 yield a Re-Os isochron age of 157.3 ± 4.3 Ma (2σ), and analyses of 11 samples from boreholes ZK12-112 and ZK16-104 yield a Re-Os isochron age of 155.6 ± 3.4 Ma (2σ). These isochron ages are within the error of the Re-Os model ages, demonstrating that the age results are reliable and that the Yuanzhuding porphyry Cu-Mo deposit formed during the late Middle Jurassic. The formation age of the Yuanzhuding Cu-Mo deposit is similar to the age of intermediate-acid rocks and W-Sn polymetallic deposits along the Chenzhou-Huaiji fault belt. This concordance suggests the same geodynamic process to the igneous activity and related mineralization, raising the potentiality of the porphyry Cu-Mo mineralization in the belt.     

Genesis of Re-rich Molybdenite in the Baishan Mo deposit,Eastern Tianshan,Xinjiang, Northwest China

The Baishan molybdenum deposit is located in the central part of the Eastern Tianshan-Beishan tectonic belt, NW China. The deposit is hosted in early Carboniferous Gandun Formation biotite-rich hornfels and is genetically related to unexposed granodiorite porphyry beneath the orebodies. The molybdenite occurs in three different types from early to late stage: Molybdenite - Fe-Cu-sulfides - K-feldspar - quartz veins (Group 1); Molybdenite - Fe-Cu-sulfides - quartz veins (Group 2); and disseminated molybdenite in the wall rock (Group 3). Rhenium concentrations in the molybdenite grains range from 108 to 277 ppm in Group 1, 69–121 ppm in Group 2 and 46–135 ppm in Group 3. The Re concentrations of molybdenite in the Baishan Mo deposit decrease from early to late and from the center to periphery, and molybdenite types vary from the 2H₁ poly-type in Groups 1 and 2 to the 2H₁ + 3R2H₁ poly-type in Group 3, based on X-ray diffraction results. The Re-enriched molybdenite probably formed from an oxidized magmatic fluid that separated from a highly oxidized and H₂O- and volatile-enriched adakitic intrusion generated in the lower crust.     

黑龙江多宝山、铜山大型斑岩铜(钼)矿床中辉钼矿的铼-锇同位素年龄

黑龙江多宝山、铜山大型斑岩铜（钼）矿床的成岩成矿年龄以往确定主要为华力西中晚期至印支期（３１１－２１９Ｍａ），本次研究测得辉钼矿ＲｅＯｓ等时线年龄为５０６±１４Ｍａ。它和用其他方法测定的同位素年龄有较大差别，从而为进一步讨论矿床的成矿作用提供了新的线索，推断此数据可能反映辉钼矿源岩下奥陶统酸性火山碎屑岩的年龄。研究还发现辉钼矿中１８７Ｏｓ的含量特高，且估算储量很大，具有巨大的潜在经济价值。     

藏东拉荣斑岩钨钼矿床辉钼矿Re- Os定年及地质意义

拉荣钨钼矿床位于类乌齐-左贡成矿带的东南部,是藏东地区发现的首例大型斑岩型钨钼矿床。其成矿地质背景尚缺乏成矿年龄制约。本文对拉荣矿床含矿石英脉中的辉钼矿进行Re-Os定年,6件样品的模式年龄集中于91.5±1.3～92.3±1.3 Ma,其加权平均年龄为91.8±0.5 Ma,等时线年龄为90.6±2.1 Ma,表明拉荣钨钼矿床成矿时代为晚白垩世。辉钼矿样品的Re含量为53.0×10~(-6)～86.1×10~(-6),表明成矿物质具有壳幔混源的特征。拉荣钨钼矿床成矿年龄指示了班公湖-怒江构造带北东侧类乌齐-左贡成矿带内存在一期晚白垩世的钨多金属成矿事件,成矿作用发生于拉萨-羌塘地体碰撞造山阶段。