镁铁质岩浆周期性补给对云南普朗斑岩Cu-Au矿床的制约:能量约束下热力学模拟

镁铁质岩浆周期性补给于硅酸质岩浆房是形成大型斑岩矿床的关键因素。本文以普朗超大型斑岩Cu-Au矿床为例,通过能量约束体系下的热力学方法模拟浅部硅酸质岩浆房中镁铁质岩浆周期性补给过程,定量评估该过程对形成大型斑岩矿床的控制作用。普朗矿床成矿前粗粒石英闪长玢岩(CQD)和成矿期石英二长斑岩(QMP)复式岩体中均普遍发育镁铁质暗色微粒包体(MMEs),岩相学特征显示斑岩体中角闪石和黑云母发育韵律环带结构或港湾状溶蚀结构以及针柱状磷灰石的存在均指示发生了镁铁质岩浆混合作用。与单一的分离结晶模型(FC)相比,多阶段岩浆补给-分离结晶模型(R3FC)显示,镁铁质岩浆的补给一方面会抑制长石的结晶,另一方面会促进钙铁镁和铁镁等多类型角闪石的形成,并大幅提前黑云母的结晶次序。以硅酸质岩浆物质摩尔分数变化与挥发分之间相关性为参照,获得的熔体H_(2) O、SCSS(硫化物饱和时硅酸盐熔体中的S含量)和Cl溶解度显示,镁铁质岩浆补给将在岩浆演化早期提高而在晚期降低残余熔体H_(2)O含量(0.16%、0.04%、-0.30%),持续提高熔体SCSS(78.74×10^(-6)、94.44×10^(-6)和137.88×10^(-6))和Cl溶解度(0.04%、0.10%和0.20%),但对Cu含量影响有限。结果表明,能量约束体系下的R3FC和FC热力学模型不仅能够合理解释普朗复式斑岩体矿物结构特征,也定量验证了镁铁质岩浆的补给对成矿岩体异常高H_(2) O、S和Cl含量的贡献。

富碱斑岩成因与Cu—Mo—Au矿床成矿作用——以金沙江—红河富碱斑岩成矿带为例

富碱斑岩因其产出构造环境独特、岩石类型特殊,并常与铜多金属矿床密切相关,而受到广泛关注。笔者等在回顾相关研究进展的基础上,通过岩石成因和构造环境、岩浆性质和岩浆源区等方面的综合研究,探讨了金沙江—红河富碱斑岩成矿带富碱岩浆成矿作用及成岩成矿机制。系统的矿床地质、年代学、地球化学等研究表明:①金沙江—红河富碱斑岩成矿带内成岩成矿作用集中于43~32 Ma,成矿富碱斑岩系始新世—渐新世I型钾玄质花岗斑岩,是印—亚大陆后碰撞背景下大陆内部大型走滑和伸展等动力过程诱导的岩浆活动产物,金沙江和哀牢山—红河断裂的差异走滑运动可能控制了成矿带差异性成岩成矿事件;②成矿带北段以Cu—Mo为主的成矿富碱斑岩源自新元古代下地壳的部分熔融,且源区有富集地幔和亏损地幔物质的加入,而南段以Cu—Au或Cu(—Mo—Au)为主的成矿富碱斑岩源自具有不同程度富集地幔物质加入的新生下地壳的部分熔融;③带内以Cu为主的斑岩—矽卡岩型矿床中成矿富碱斑岩的氧逸度(ΔFMQ)与矿床规模具有正相关性。除受氧逸度控制外,源区高K2O含量有利于斑岩—矽卡岩型Au矿床的形成。该研究对金沙江—红河富碱斑岩成矿带乃至同类矿床研究和找矿勘查具有理论和实际意义。

^40Ar/^39Ar and Rb-Sr Ages of the Tiegelongnan Porphyry Cu-(Au)Deposit in the Bangong Co-Nujiang Metallogenic Belt of Tibet,China:Implication for Generation of Super-Large Deposit

The Tiegelongnan deposit is a newly discovered super-large porphyry-epithermal Cu-（Au） deposit in the western part of the Bangong Co-Nujiang metallogenic belt, Tibet（China）. Field geology and geochronology indicate that the porphyry mineralization was closely related to the Early Cretaceous intermediate-felsic intrusions（ca. 123–120 Ma）. Various epithermal ore and gangue mineral types were discovered in the middle-shallow part of the orebody, indicating the presence of epithermal mineralization at Tiegelongnan. Potassic, propylitic, phyllic and advanced argillic alteration zones were identified. 40Ar/39Ar dating of hydrothermal biotite（potassic zone）, sericite（phyllic zone）, and alunite（advanced argillic zone） in/around the ore-bearing granodiorite porphyry yielded 121.1±0.6 Ma（1σ）, 120.8±0.7 Ma（1σ） and 117.9±1.6 Ma（1σ）, respectively. Five hydrothermal mineralization stages were identified, of which the Stage IV pyrite was Rb-Sr dated to be 117.5±1.8 Ma（2σ）, representing the end of epithermal mineralization. Field geology and geochronology suggest that both the epithermal and porphyry mineralization belong to the same magmatic-hydrothermal system. The Tiegelongnan super-large Cu-（Au） deposit may have undergone a prolonged magmatichydrothermal evolution, with the major mineralization event occurring at ca.120–117Ma.

Petrogenesis and Tectonic Significance of the Three-Period Porphyries from the Daruoluolong Cu(Au) Deposit, Tibet, China

Objective The Daruoluolong deposit is the first high-grade Cu(Au)deposit discovered in the middle section of the Bangonghu-Nujiang(herein after referred to as Ban-Nu)metallogenic belt,which has not been documented about previously.This deposit is located in Shuanghu County of northern Tibet,and its geotectonic position belongs to the

Origin of the Newly Discovered Zhunuo Porphyry Cu-Mo-Au Deposit in the Western Part of the Gangdese Porphyry Copper Belt in the Southern Tibetan Plateau,SW China

The newly discovered Zhunuo porphyry Cu-Mo-Au deposit is located in the western part of the Gangdese porphyry copper belt in southern Tibet, SW China. The granitoid plutons in the Zhunuo region are composed of quartz diorite porphyry, diorite porphyry, granodiorite porphyry, biotite monzogranite and quartz porphyry. The quartz diorite porphyry yielded zircon U-Pb ages of 51.9±0.7 Ma（Eocene） using LA-ICP-MS, whereas the diorite porphyry, granodiorite porphyry, biotite monzogranite and quartz porphyry yielded ages ranging from 16.2±0.2 to 14.0±0.2 Ma（Miocene）. CuMo-Au mineralization is mainly hosted in the Miocene granodiorite porphyry. Samples from all granitoid plutons have geochemical compositions consistent with high-K calc-alkaline series magmatism. The samples display highly fractionated light rare-earth element（REE） distributions and heavy REE distributions with weakly negative Eu anomalies on chondrite-normalized REE patterns. The trace element distributions exhibit positive anomalies for large-ion lithophile elements（Rb, K, U, Th and Pb） and negative anomalies for high-field-strength elements（Nb and Ti） relative to primitive mantlenormalized values. The Eocene quartz diorite porphyry yielded εNd（t） values ranging from-3.6 to-5.2,（-（87）Sr/-（86）Sr）i values in the range 0.7046–0.7063 and initial radiogenic Pb isotopic compositions with ranges of 18.599–18.657 -（206）Pb/-（204）Pb, 15.642–15.673 -（207）Pb/-（204）Pb and 38.956–39.199 -（208）Pb/-（204）Pb. In contrast, the Miocene granitoid plutons yielded ε（Nd）（t） values ranging from-6.1 to-7.3 and（87Sr/86Sr）i values in the range 0.7071–0.7078 with similar Pb isotopic compositions to the Eocene quart diorite. The Sr-Nd-Pb isotopic compositions of the rocks are consistent with formation from magma containing a component of remelted ancient crust. Zircon grains from the Eocene quartz diorite have ε（Hf）（t） values ranging from-5.2 to ＋0.9 and two-stage Hf model ages ranging from 1.07 to 1.46 Ga, while zircon grains from the Miocene granitoid plutons have ε（Hf）（t） values from-9.9 to ＋4.2 and two-stage Hf model ages ranging from 1.05–1.73 Ga, indicating that the ancient crustal component likely derives from Paleo- to Mesoproterozoic basement. This source is distinct from that of most porphyry Cu-Mo-Au deposits in the eastern part of the Gangdese porphyry copper belt, which likely originated from juvenile crust. We therefore consider melting of ancient crustal basement to have contributed significantly to the formation Miocene porphyry Cu-Mo-Au deposits in the western part of the Gangdese porphyry copper belt.

Geochronology and Geochemistry of Metallogenetic Porphyry Bodies from the Nongping Au-Cu Deposit in the Eastern Yanbian Area, NE China: Implications for Metallogenic Environment

The metallogenetic porphyry bodies in the Nongping Au-Cu deposit, in the eastern Yanbian area, mainly include porphyritic granodiorite and biotite granodiorite porphyry. They are featured with high silicon and enrichment in sodium, and classified into sodic rocks of low-K tholeiitic basalt series. Except slightly low Sr content, the rock basically has the geochemical characteristics of the adakite： relatively high A12O3 content, relatively low MgO content, depletion in Y and Yb; relative enrichment in large ion lithophile elements （LILEs） and light rare-earth elements （LREEs）, relatively low content of high field strength elements （HFSEs）; positive Eu anomaly or weak negative Eu anomaly. In situ zircon dating technology LA-MC-ICP-MS was used to conduct single-grain zircon dating of biotite granodiorite porphyry, and the results show that the age of metallogenetic porphyry body is 100.04±0.88 Ma, indicating that the porphyry bodies were emplaced in the late Cretaceous period. According to the regional tectonic setting and the comparison with the same kind of deposits, we think that the metallogenetic porphyry bodies in the Nongping Au-Cu deposit have a close genetic connection with the subduction of the Pacific plate in the late Yanshanian period. The adakitic magma generated from partial melting of the subducting plate has high formation temperature, high oxygen fugacity, and volatile constituents＇ enrichment, so it is helpful for enrichment of metallogenetic elements and plays an important role in the formation of porphyry Au-Cu deposits in this region.

^(40)Ar/^(39)Ar Dating of the Shaxi Porphyry Cu-Au Deposit in the Southern Tan-Lu Fault Zone, Anhui Province

Four samples of plagioclase and biotite from the Shaxi porphyry in the lower part of the Yangtze metallogenic belt were analyzed for age determination with the ^40 Ar/^39Ar method. The results yield reproducible ages of 126 Ma to 135 Ma with a high level of confidence according to the agreement between isochron and plateau ages. The four Ar-Ar ages are relatively consistent within the analytical error. These ages are also consistent with, but more precise than, previous K-Ar and Rb-Sr ages and thus provide better constraints on the time of porphyry formation and associated Cu-Au mineralization along the middle to lower part of the Yangtze metallogenic belt. The ages of 126 to 135 Ma are interpreted to represent the intrusive time of the Shaxi porphyry, so that the Cu-Au mineralization should have occurred later due to the post-magmatic hydrothermal event.

Contrast in Fluid M etallogeny between the Tianmashan Au-S Deposit and the Datuanshan Cu Deposit in Tongling,Anhui Province

A comprehensive contrast of ore-forming geological background and ore-forming fluid features, especially fluid ore-forming processes, has been performed between the Tianmashan and the Datuanshan ore deposits in Tongling, Anhui Province. The major reasons for the formation of the stratabound skarn Au-S ore deposit in Tianmashan and the stratabound skarn Cu ore deposit in Datuanshan are analyzed in accordance with this contrast. The magmatic pluton in Tianmashan is rich in Au and poor in Cu, but that in Datuanshan is rich in Cu and Au. The wallrock strata in Tianmashan contain Au-bearing pyrite layers with some organic substance but those in Datuanshan contain no such layers. Moreover, the ore-forming fluids in Tianmashan are dominantly magmatic ones at the oxide and sulfide stages, but those with high content of Cu in Datuanshan are mainly groundwater fluids. In addition, differences in compositional evolution and physicochemical condition variation of the ore-forming fluids result in gradual dispersion

Geochemical studies on REE and trace elements from several Cu-Au deposits along the lower Yangtze metallogenic valley, central-southern Anhui Province

The Yangtze Valley was one of the most important metallogenic regions during the Jurassic-Cretaceous period in East China, where more than 200 polymetallic Cu-Fe-Au, Mo, Zn, Pb, Ag deposits have been found. Trace elements were chemically analyzed and the relevant data were collected from literature for the Yanshanian (Mesozoic) igneous rocks which have close relationship with Cu-Au mineralization. Copper mineralization in the lower Yangtze Valley can be divided into three major types: skarn type, porphyry type and volcanic type. The porphyry type is of rare occurrence, such as the Shaxi porphyry copper deposit in the northern part of the lower Yangtze metallogenic valley. This paper focuses on the REE and trace element geochemistry of several Cu-Au deposits along the lower part of Yangtze metallogenic valley in Anhui. The results showed that there are differences in REE distribution for these four types of Cu-Au mineralization, which confine the sources of REE and trace elements as well as other mantle and transitional compatible elements. The results of both REE and trace element geochemical studies showed that these elements with different characteristics have different origins, probably representing different sources of Cu-Au deposits in the deep crust and upper mantle environments. The 40Ar/39Ar dating of one biotite sample gave an age of 131 Ma with a high level of confidence, which represents the age of formation of the Shaxi porphyrite intrusive with porphrytic Cu-Au mineralization, which is consistent with that of the majority of the adjacent acid intrusives with mass Cu-Au mineralization along the Yangtze metallogenic belt in the Yanshanian period (Mesozoic). This is the first attempt to use the high precision method to date the Shaxi porphyrite intrusive.

Metallogenic mechanisms of super-large Cu and Au deposits in the Dexing region and simulating experiments

Based on the results of previous studies and under the direction of the theory of "ore deposit genesis",the authors made use of high temperature and high pressure experimental facilities and conditions at the Tectono-geochemistry Research Room under the State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,and put the focus on the multi-source of tectonically controlling ore-forming materials,the characteristics of multi-stage and multi-episode hydrothermal activities and mineralization and the characteristics of multi-genesis and multi-ore deposition so as to shed light on the metallogenic mechanisms of super-large Cu and Au deposits.In addition simulating experiments were made on multi-stage and multi-episode tectonic activities and rock and ore deformation,multi-stage and multi-episode tectonic activities and mobilization and migration of ore-forming materials,and multi-stage and multi-episode tectonic activities and superimposition and enrichment of ore-forming materials.The experimental results showed that under the action of multi-stage and multi-episode tectonic stress the deformation and fragmentation of not only rocks and ores have been intensified,and but also the ore-forming materials originally disbursed in the rocks and ores have been mobilized and migrated and superimposed and enriched.The experimental results also provided the scientific experimental data and grounds for deep-going research on the rules of metallogenesis and geneses of super-large ore deposits in the Dexing region,Jiangxi Province.

Geological, Alteration and Mineralization Characteristics of Ali Javad Porphyry Cu-Au Deposit, Arasbaran Zone, NW Iran

Ali Javad porphyry Cu-Au deposit is located 20 Km north of Ahar city in Arasbaran metallogenic zone which is considered as a part of Alp-Himalayan mineralization belt. Magmatism in this area began in Late Cretaceous, followed by extensive magmatism in Cenozoic and Quaternary periods. Porphyry type mineralization developed in Ali Javad quartz monzonitic porphyry stock and Eocene pyroclastic and volcanic country rocks. Ali Javad porphyry intrusion has shoshonitic nature and shows characteristics of volcanic arc granitoids that it is have been emplaced in a post-collision tectonic setting. Alteration zones at the deposit demonstrated zoning which is comparable with Lowel-Guilbert model proposed for quartz-monzonite type porphyry copper deposits. Phyllic, argillic, silicic and propylitic alteration zones were observed at the surface while potassic alteration zone could be observed at depth in drill core samples. Mineralization was recognized both as supergene and hypogene, the latter was as veins, veinlets and disseminations. Dominant hypogene minerals were chalcopyrite, bornite, molybdenite, pyrite and magnetite while chalcocite, covellite and limonite were dominant supergene minerals. Four mineralization zones were observed in the deposit as leached, transitional, supergene and hypogene zones. Average grades were 0.75% for copper and 1.86 ppm for gold with 81.5 Mt proved reserve for copper and 37.8 Mt for gold.

冈底斯东段南部第三纪夕卡岩型Cu-Au±Mo矿床地质特征、矿物组合及其深部找矿意义

在冈底斯Cu—Au成矿带东南部的山南地区分布有克鲁、劣布、冲木达和陈坝等中到大型Cu—Au±Mo矿床。与含铜夕卡岩有关的侵入岩形成于20～30Ma之间，为高钾钙碱性中酸性浅成岩，形成于印-亚大陆碰撞晚期构造背景。矿化赋存于岩体外接触带下白垩统比马组的碳酸盐岩和其他钙质岩石内。主要矿化类型为夕卡岩型、热液脉型和斑岩型，构成完整的斑岩-夕卡岩、热液脉状铜-金（钼）多金属成矿体系，矿化组合主要为Cu—Mo、Cu—Au和Cu。外接触带的蚀变以夕卡岩化、角岩化为主，而内接触带上主要为岩体的绢云母化、硅化、绿泥石化等，内夕卡岩不发育。夕卡岩化可分为早期夕卡岩和晚期含水硅酸盐阶段。早期夕卡岩主要为钙铁、钙铝石榴石夕卡岩，含少量透辉石、磁铁矿等，晚期的含水硅酸盐阶段主要是绿泥石-绿帘石、方解石、石英交代石榴石夕卡岩，并伴随含铜硫化物的沉淀，为本区夕卡岩型铜矿形成的主要阶段。含铜硫化物以富含斑铜矿为特征，Au、Ag主要赋存于斑铜矿、硫铋铜矿及黄铜矿等矿物中。山南地区的夕卡岩型铜-金矿床均为浅部夕卡岩，在某些夕卡岩型铜金矿床中显示了斑岩型矿化的存在，可能暗示该区的夕卡岩型矿化与北带相似，具有统一的斑岩型-夕卡岩型成矿系统。因此本区具有在深部寻找斑岩型金矿的可能性，而且找矿潜力较大。

鄂东南地区Cu-Au-Mo-(W)矿床的成矿时代及其成矿地球动力学背景探讨:辉钼矿Re-Os同位素年龄

鄂东南地区Cu-Au-Mo-(W)矿床是长江中下游地区金属成矿带的重要组成部分。本文利用Re-Os同位素定年方法对该地区5个典型矿床(丰山洞铜钼金银多金属矿床、阮家湾钨铜钼矿床、千家湾铜金矿床、铜绿山铜铁金钼多金属矿床和铜山口铜钼矿床)进行了成矿时代的研究,获得其辉钼矿Re-Os同位素年龄分别为(144.0±2.1)Ma、(143.6±1.7)Ma、(137.7±1.7)Ma、(137.8±1.7)^(138.1±1.8)Ma和(143.5±1.7)^(142.3±1.8)Ma,代表各矿床的成矿时代。研究结果表明,鄂东南矿集区内的Cu-Au-Mo-(W)矿床与铜陵、安庆、九瑞矿集区内的矿床几乎是同时形成的,成矿时代可能主要集中于(140±5)Ma,相当于晚侏罗世-早白垩世。在综合已有的岩石学、地球化学和地球物理学资料的基础上,笔者认为,这一成矿事件的深部动力学过程可能是处于中国东部南北向印支期构造域向北东向古太平洋构造域大转折的背景下,与软流圈上涌和玄武质岩浆底侵而导致壳幔同熔有关。

青海东昆仑托克妥Cu-Au(Mo)矿床含矿斑岩成因:锆石U-Pb年代学和地球化学约束

东昆仑造山带是我国斑岩型矿床的重要成矿区之一。对东昆仑托克妥Cu-Au（Mo）矿床含矿斑岩利用原位LA-ICP-MS锆石U-Pb测年和地球化学分析方法,探讨该地区岩体成因以及岩浆作用与成矿作用的深部约束机制。东昆仑托克妥Cu-Au（Mo）矿床含矿二长花岗斑岩年龄为（232.49±0.93）Ma,花岗闪长斑岩年龄为（232.6±1.2）Ma,处于东昆仑碰撞造山阶段。含矿斑岩为二长花岗斑岩和花岗闪长斑岩,具有富硅（w（SiO2）=63.11%~71.78%）、高钾（w（K2O）=2.62%~3.61%）、高镁（w（MgO）=0.52%~1.89%）、低钛（w（TiO2）=0.26%~0.53%）和偏铝质（A/CNK=1.05~1.10）的特征,富集大离子亲石元素Rb、Ba、K和Pb等,亏损高场强元素Nb、Ta、Ti和P,属于高钾钙碱性系列的I型花岗岩。研究认为,托克妥Cu-Au（Mo）矿床形成于大陆动力体制下的伸展背景,与阿尼玛卿洋壳岩石圈北向俯冲碰撞有关的俯冲板片断离有关。

东疆红山高硫型浅成低温Cu-Au矿床氧化带钾铁矾、板铁矾、副基铁矾的首次发现及其意义

新疆哈密红山高硫化物型浅成低温Cu-Au矿床的氧化带呈漏斗状产于原生硫化物矿体的上部,延深50～60m,以硫酸盐矿物为主。X射线粉晶衍射、湿法化学和差热分析研究表明,钾铁矾、板铁矾和副基铁矾3种硫酸盐矿物均系在中国首次发现。钾铁矾湿法化学分析为:H2O6.35%,SO349.72%,Na2O0.15%,Fe2O326.00%,K2O12.47%,FeO0.25%,SiO23.25%,不溶物0.85%,CaO0.11%,总计99.15%;XRD特征谱线为:4.40(100),4.26(70),6.58(47)。板铁矾湿法化学分析为H2O26.51%,SO349.91%,Na2O0.03%,Fe2O322.52%,MgO0.01%,CaO0.03%,总计99.01%;XRD特征谱线为:9.16(100),3.29(9),4.06(8)。副基铁矾湿法化学分析为H2O24.82%,SO338.53%,Al2O30.18%,Fe2O336.10%,MgO0.02%,CaO0.04%,总计99.69%;XRD特征谱线为:5.00(100),3.11(41),5.85(39)。热分析实验进一步验证了化学分析的可靠性,并对这些硫酸盐热反应机制作了解释。该类硫酸盐矿物已作为新型资源直接制酸用于湿法炼铜,具有选矿和环保上的巨大优势。对该类硫酸盐矿物的共生组合、形成次序、形成条件的深入研究还可用来反演古环境和古气候。

东天山红山Cu-Au矿床氧化带首次发现的副针绿矾巨晶及其多型针绿矾

一种艳丽的蓝紫色矿物巨晶在我国新疆哈密地区红山铜-金矿床氧化带中、上部大量出现,经详实的野外地质观察和室内测试,如 X-射线单晶及粉晶衍射测定、湿法化学分析、热分析、穆斯堡尔谱和红外光谱测试等,确认其为一罕见硫酸盐矿物—副针绿矾(Paracoquimbite,Fe_2(SO_4)_3·9H_2O),是继智利丘基卡马塔巨型斑岩铜矿区1935年报道后,在世界上的又一次发现,在我国尚属首次。该矿物晶体如此之硕大(单晶粒度可达8cm～12cm),远大于智利首次发现的晶体(1.95cm),在国内外和自然界亦堪称首例,与副针绿矾密切共生者为针绿矾,二者呈多型关系。本文副针绿矾湿法化学分析结果为(wt%):SO_3 42.55,Fe_2O_3 28.19,H_2O 28.72,CaO 0.02,MgO 0.01,Al_2O_3 0.03,Na_2O 0.02,总计99.54,其 XRD 特征谱线为:4.61(100),8.89(83),3.38(67);针绿矾湿法化学分析结果为(wt%):SO_342.31,Fe_2O_3 28.61,H_2O 28.98,MgO 0.01,Al_2O_3 0.01,总计99.92,其 XRD 特征谱线为:8.27(100),5.46(76),2.77(76)。红外光谱分析判定了不同基团及同一种基团在不同结构环境下振动模式或频率的差别。穆斯堡尔谱分析确定了副针绿矾和针绿矾中铁的氧化态、配位数以及结构中存在共价键(π键),其穆斯堡尔谱共有特征是四极矩分裂值较小,均由单一吸收峰组成。各种实验分析数据完全吻合,保证了副针绿矾和针绿矾研究的准确性和可靠性。在同一标本上连续切片,通过连续系统的电子探针分析,对针绿矾与副针绿矾互为多型的成因机理做了初步探讨。红山矿区氧化带中除与该矿物副针绿矾共生者外,尚有其它多种硫酸盐矿物亦为我国首次发现。目前上述诸多矿物已作为湿法冶铜及制酸工业的新型资源,副针绿矾巨大晶体的发现兼有一定的实用价值和收藏价值。

云南金平铜厂斑岩Cu(Mo-Au)矿床含矿石英正长斑岩地球化学特征及成因机制探讨

铜厂斑岩型Cu(Mo-Au)矿床位于金沙江-红河富碱侵入岩带的南段,其含矿的石英正长斑岩侵入体属金沙江-红河富碱侵入岩带的重要组成部分。对铜厂石英正长斑岩开展详细的地球化学研究结果表明,其具有高碱、富钾及准铝质-弱过铝质等特征,属钾玄岩系列岩石;微量和稀土元素分析表明,铜厂石英正长斑岩明显富集Rb、Ba、Th、U、K、La和Sr等大离子亲石元素,相对亏损Nb、Ta和Ti等高场强元素,具有明显的"TNT"负异常,稀土总量高,明显富集轻稀土而亏损重稀土,轻重稀土分馏显著;(87Sr/86Sr)i为0.707097～0.707138,εNd(t)为-7.1～-6.8,在Sr-Nd同位素相关图上,与EMII来源岩石相似。对比金沙江-红河富碱侵入岩带北段的玉龙含矿的二长花岗斑岩和中段的马厂箐含矿的花岗斑岩的地球化学特征,铜厂含矿斑岩具有高的全碱、微量元素和稀土元素含量、高的(87Sr/86Sr)i值和低的εNd(t)值、不具埃达克质岩属性等特征。综合研究表明,铜厂含矿的石英正长斑岩在成因类型上属于A型花岗岩类,形成于～35Ma的晚碰撞走滑环境且直接起源于EMII地幔的部分熔融。铜厂与玉龙及马厂箐斑岩型Cu(Mo-Au)矿床含矿斑岩地球化学特征和成矿规模存在差异,与源区物质的部分熔融程度和地壳物质的混染程度密切相关。

东疆红山Cu-Au矿床氧化带中铜叶绿矾和高铁叶绿矾的首次发现及其矿物学特征

叶绿矾族矿物是硫化物矿床氧化带的特殊产物，被认为是硫化物矿床的“标志矿物”，分布在氧化带的上部，并与其他高铁硫酸盐共生。特定的地质环境和矿床类型发育有不同的叶绿矾族矿物。新疆哈密红山高硫化物型浅成低温Cu-Au矿床火山机构和次火山岩相控矿作用十分明显，形成于中生代，其成因类型为浅成低温热液型金矿-斑岩铜矿之间过渡的“紫金山式”金铜矿床。其氧化带呈漏斗状产于原生硫化物矿体的上部，延深约50～60m，以硫酸盐矿物为主。利用X射线粉晶衍射、湿法化学和差热分析，在红山氧化带发现了铜叶绿矾、高铁叶绿矾，这两种叶绿矾族矿物均系在中国首次发现。铜叶绿矾湿法化学分析结果为[w（B）／%]H2O 30．87，SO3 36．76，Na2O 0．03，Fe2O3 23．40，CuO 6．27，MgO 0．01，Al2O3 0．01，不溶物0．28，CaO 0．03，总计97．66；其XRD特征谱线为：6．03（100），7．39（95），9．04（65）。高铁叶绿矾湿法化学分析结果为[w（B）／％]：H2O 28．15，SO3 37．02，K2O 3．88，Fe2O3 27．75，Na2O 1．30，MgO 1．86，不溶物0．24，总计100．20；其XRD特征谱线为：9．07（100），6．04（89），5．59（50）。红外和热分析实验进一步验证了化学分析数据的可靠性，并对这些硫酸盐热反应机制和相变过程作了解释。目前该类硫酸盐矿物已作为新型环保资源直接制酸用于湿法炼铜。

巴基斯坦雷克迪克矿集区斑岩Cu-Au矿床(点)地质及动力学研究进展

系统总结了近年来有关巴基斯坦雷克迪克斑岩型Cu-Au矿集区的地质、岩石和地球动力学演化的研究成果,指出该矿集区斑岩型Cu-Au矿床(点)的形成与板块的拼合以及特提斯构造域的演化密切相关,是在后碰撞地壳伸展阶段由早中新世和中中新世的岩浆-热液作用形成的,且早中新世的斑岩型Cu(Au)矿床(点)主要受石英闪长斑岩和闪长斑岩侵入体控制,中中新世的斑岩型Cu-Au矿床(点)矿体主要受花岗闪长岩和石英闪长岩侵入体控制。

山东七宝山隐爆角砾岩型Cu-Au矿床流体包裹体及成矿流体演化特征

山东七宝山隐爆角砾岩型Cu-Au矿床位于郯庐断裂带东侧,矿体主要赋存在七宝山杂岩体中。通过显微学观察,发现在深部蚀变斑岩的重结晶石英斑晶中发现了含子晶包裹体（Type 1型）,同时伴生有气相（Type 2型）和富气相水溶液（Type 3型）包裹体。浅部矿坑石英脉中的流体包裹体主要为气液两相包裹体,并对较为发育的石英晶柱进行了详细的阴极发光特征和显微学观察研究。从其根部到末端可以划分为三个期次,其中第一期次石英环带中主要发育富液相包裹体（Type4型）,另外还发育少量的负晶形气液两相包裹体（Type 5型）,第二期石英环带中主要发育Type 5型包裹体,第三期石英环带中主要发育形态各异的气液两相包裹体（Type 6型）。显微测温结果显示,Type 1型包裹体均表现为子晶熔化均一特征,均一温度介于375-450℃之间,计算获得的盐度为43.8%-52.2%NaCleqv;Type 3型包裹体表现为临界均一特征,均一温度介于347-420℃之间,估算盐度为0.8%-7.1%NaCleqv;Type 4,5和6型包裹体均均一至液相,均一温度分别为221-327℃、199-379℃以及109-193℃,相应的盐度为2.4%-7.8%NaCleqv、10.2%-16.8%NaCleqv以及0.3%-4.0%NaCleqv。热力学计算获得Type 1型包裹体均一压力为623.46-1111.82bar,平均855.70bar。Type 3型包裹体均一压力范围为139.18-362.47bar,平均为250.70bar。由此可以认为,尽管富气相包裹体和含子晶包裹体共存,并且具备相近的均一温度范围,但是压力相差极为明显,所以这种共存特征并不能表征流体沸腾作用。根据前人实验研究结果,本文认为Type 2和3型包裹体代表了斑岩体结晶早期由于上覆地层隐爆而导致的压力降低条件下分异出来的流体,由于角砾岩筒后续固结引起压力增加,由Type 1型含子晶包裹体所代表的高盐度流体逐渐从成矿岩体中分异出来。当这两种流体沿裂隙通道向上运动时,被同期石英包裹体捕获而共存。这部分流体代表了深部斑岩成矿系统的流体。根据H-O-S同位素研究,Type 4和5包裹体主要来自岩浆流体,并且在后期经历了大气降水的混合,形成了Type 6型流体。这部分流体则代表了浅成热液系统的流体。由于Type 3和4型包裹体均为岩浆成因流体,两者盐度范围一致（5.0%-7.0%NaCleqv）,并且随着温度的下降,密度演化趋势明显,从0.4101增加至0.8816g/cm^3。本文认为代表斑岩系统的深部富气相成矿流体在向上逃逸过程中由于压力扰动而在超临界区域内发生相态收缩,随着温度下降形成了富液相成矿流体,转变为浅成热液系统的流体,在此过程中不会发生流体沸腾。由于Cu和Au易于被HS-络合而在气相中运移,并且液相流体之间的混合能力较强,所以当含金的富气相流体收缩成富液相流体时,可以与浅部的天然降水或者富Fe流体发生任意比例的混合,导致了Cu和Au的卸载成矿,这应该是七宝山Cu-Au矿化主要的成矿机制,但是不排除由于温度和压力的下降而引发的金属矿物沉淀成矿。