Sorkhe‐Dizaj Iron Oxide–Apatite Ore Deposit in the Cenozoic Alborz‐Azarbaijan Magmatic Belt,NW Iran

The Sorkhe‐Dizaj iron oxide–apatite deposit in the Cenozoic Alborz‐Azarbaijan magmatic belt, NW Iran, is hosted mainly by a Late Eocene to Oligocene quartz‐monzonitic body, and subordinately in the Eocene volcanic and volcanoclastic sequences. The Sorkhe‐Dizaj intrusive body is an I‐type granitoid of the calc‐alkaline series. Mineralization is associated with actinolization, K‐feldspar, sericitic, propylitic, and tourmaline alteration types. The orebodies are massive, banded, stockwork, and breccia in shape and occur mainly along the fault zones within the quartz‐monzonitic intrusion, volcanic, and volcanoclastic rocks. Ore minerals dominantly comprise magnetite, apatite, and monazite, as well as minor amounts of chalcopyrite, bornite, and pyrite. Four major paragenetic stages are discriminated in the mineralization including early, oxide, sulfide, and late stage. The Sorkhe‐Dizaj deposit is similar in the aspects of host rock lithology, alteration, and mineralogy to the Kiruna‐type deposits associated with minor Cu sulfide minerals. Spatial and temporal association of the mineralization with the Late Eocene–Early Oligocene quartz‐monzonite intrusive body suggests that the ore fluid was probably related to magmatic activity.     

Genetic nature of apatite–magnetite ore in North Gurvunur deposit,western Transbaikal region

The paper gives a mineralogical and geochemical characterization of the North Gurvunur deposit, which was discovered in the Eravna ore district. The ore is composed of apatite–magnetite paragenesis. Apatite is distinguished by elevated LREE concentrations; some of them are contained in emulsion-type impregnation of monazite. Hematitization, carbonate, quartz, and pyrite veinlets formed at the postore stage, and gypsum–anhydrite mineralization is widespread in the supraore sequence. Two groups of endogenic minerals are distinguished by oxygen isotopic composition. One of them comprises magnetite and apatite, which are characterized by a homogeneous composition throughout the section of the ore lode and are close to the mantle source. The oxygen–isotope temperature calculated for the apatite–magnetite couple (620–800°C) provides evidence for magmatic origin of ore. The δ¹⁸O of fluid in equilibrium with hematite is 8.0–8.5‰ and shows a certain enrichment in crustal component; carbonates of postore veinlets reveal participation of meteoric water. The study has made it possible to refer the North Gurvunur deposit to the Kiruna type.     

含铀副矿物的热液蚀变：来自华南鹿井矿田碎裂蚀变岩型铀矿床的矿物学研究

花岗岩型铀矿中铀的来源问题，长期以来是铀矿床学研究的热点问题之一。大多数学者认为其成矿物质主要来源于花岗岩本身的含铀副矿物，然而对于含铀副矿物热液蚀变行为研究较少。鹿井铀矿田位于诸广山复式岩体的中部，是华南最主要花岗岩型铀矿田之一，碎裂蚀变岩型铀矿化在该矿田内占主导地位。小山铀矿床位于鹿井矿田中部，是近些年新发现的碎裂蚀变岩型矿床。本文以钻孔ZK1- 1为研究对象，对热液蚀变带开展了精细矿物学研究。研究表明：蚀变带中发育有晶质铀矿、铀石—钍石、独居石、磷钇矿、锆石、磷灰石、金红石等含铀副矿物。晶质铀矿、铀石—钍石中铀含量高，热液蚀变条件不稳定，铀容易释放；独居石蚀变为直氟碳钙铈矿和磷钇矿蚀变为次生磷灰石过程中容易释放出铀；锆石因结构稳定，铀难以释放；磷灰石、金红石中铀含量较低，供铀能力差。综合分析认为花岗岩中晶质铀矿、铀石—钍石是主要铀源矿物，独居石、磷钇矿为次要铀源矿物。     

辽宁弓长岭铁矿床磁铁矿稀土元素特征及其地质意义

辽宁弓长岭铁矿床是我国著名的沉积变质型铁矿床,其二矿区的磁铁富矿达大型规模,属国内之最.为探讨弓长岭铁矿床铁矿的物质来源、形成环境和富矿成因,本文以二矿区六个铁矿体的贫铁矿石和富铁矿石中磁铁矿单矿物为研究对象,利用电感耦合等离子体质谱进行了系统的稀土元素测试.结果表明,所有样品中磁铁矿的稀土元素总量(∑REEs)和Y具有非常一致的特征:稀土元素总量较低,Y/Ho比值较高;经太古界后平均澳大利亚页岩( PAAS)标准化呈现重稀土相对富集、轻稀土相对亏损的分馏模式,大部分呈现La正异常,所有样品都有明显的Eu和Y正异常,这些特征表明研究区的磁铁矿成矿物质主要来源于海底高温热液和海水;虽然磁铁矿的Ce/Ce*为0.69～ 0.97,但大多数样品缺乏真正意义的Ce负异常,这暗示其沉积于还原的海水环境;富铁矿石磁铁矿的稀土元素总量和Eu含量明显高于贫铁矿石的磁铁矿,而且含富矿的上含铁带Eu异常明显较高,表明富铁矿石磁铁矿具有更明显的热液特征,是在贫铁矿石的基础上受热液活动形成的.     

Geochemistry and Genesis of Iron-apatite Ore in the Khanlogh Deposit, Eastern Cenozoic Quchan-Sabzevar Magmatic Arc, NE Iran

The Khanlogh deposit in the Cenozoic Quchan-Sabzevar magmatic belt, NE Iran, is hosted by Oligocene granodioritic rock. The Khanlogh intrusive body is I-type granitoid of the calc-alkaline series. The orebodies are vein, veinlet, massive, and breccia in shape and occur along the fault zones and fractures within the host rock. Ore minerals dominantly comprise magnetite and apatite associated with epidote, clinopyroxene, calcite, quartz, and chlorite. Apatites of the Khanlogh deposit have a high concentration of REE, and show a strong LREE/HREE ratio with a pronounced negative Eu anomaly. Magnetites have a high concentration of REE and show weak to moderate LREE/HREE fractionation. They are comparable to the REE patterns in Kiruna-type iron ores and show an affinity to calc-alkaline magmas. The Khanlogh deposit is similar in the aspects of host rock lithology, alteration, mineralogy, and mineral chemistry to the Kiruna-type deposits. Field observations, hydrothermal alteration halos, style of mineralization, and the geochemical characteristics of apatite, magnetite, and host rock indicate that these magnetite veins have hydrothermal origin similar to Cenozoic Kiruna-type deposits within the Tarom subzone, NW Iran, and are not related to silica-iron oxide immiscibility, as are the major Precambrian magnetite deposits in central Iran.     

Rare earth elements in apatite and magnetite in Kiruna-type iron ores and some other iron ore types

An investigation of the content and distribution of REE in apatite and magnetite in the iron ores of Kiruna type and some other iron ores is presented. REE in apatite and magnetite in different ore types show characteristic patterns which are related to different modes of formation of the ores.The magnetite-apatite iron ores of the world can be divided into two types: (a) Kiruna iron ores proper which occur in volcanic rocks, and (b) iron ores connected with deuteric processes and/or related to intrusive rocks. Apatite of the Kiruna ores proper in Fennoscandia (e.g. Kiirunavaara, Malmberget and Grängesberg) shows a common pattern with 2000–7000 ppm REE, a weak to moderate LREE/HREE fractionation and negative Eu anomalies. In the Kiruna area, apatite of the main, P-poor ores and of the later, hydrothermal-exhalative P-rich ores, have the same REE distribution which indicates a common source. There is a similar REE distribution in magnetite-apatite trachytic-rhyodacitic host rock which confirms a close magmatic relationship. Apatite in phosphorites (such as the Paleoproterozoic Påläng deposit in northern Sweden) has a different composition (< 1000 ppm REE with Ce depletion) which excludes a sedimentary origin of the Kiruna apatite.Apatite in other volcanogenic magnetite-apatite ores outside Fennoscandia differ by a stronger LREE/HREE fractionation and by a medium to large Eu depletion, partly indicating a relationship to alkaline intrusions. The Avnik apatite, Turkey, shows a weak differentiation in combination with a pronounced negative Eu anomaly, indicating provenance from silicic magmatic sources.The REE pattern of apatite in the deuteric-hydrothermal apatite-bearing iron ores is in general similar to that of apatite in the Kiruna iron ores proper. The similarity indicates a common process of formation for both ore types.The apatite-iron ores of the Kiruna type proper were formed by a late-magmatic differentiation. The ores of the Kiruna area are, in similarity with some other magnetite-apatite ores, emplaced along regional fracture-fault lines and close to an older basement. In general the REE pattern of apatite in the different deposits shows an affinity to alkaline or sub-alkaline magmas, indicating a rifting environment. The alkaline, trachytic volcanics hosting the Kiruna ores in northern Sweden are clearly related to an extensional setting where rifting was important. A probable source for this large-scale ore-forming process was partial melting of deep-seated rocks. The ores evolved in an intracontinental setting with magma generation caused by underplating of older crust.The process giving rise to magnetite-apatite ores of the Kiruna type has occurred during the time span from Paleoproterozoic to Tertiary. The Proterozoic ores occur mainly in cratonized areas, whereas the younger ones occur in fold belts. The amount of ore formed in post-Proterozoic time is as large as that formed in Proterozoic time.     

Thorium-poor monazite and columbite-(Fe) mineralization in the Gleibat Lafhouda carbonatite and its associated iron-oxide-apatite deposit of the Ouled Dlim Massif,South Morocco

Recent exploration work in South Morocco revealed the occurrence of several carbonatite bodies, including the Paleoproterozoic Gleibat Lafhouda magnesiocarbonatite and its associated iron oxide mineralization, recognized here as iron-oxide-apatite (IOA) deposit type. The Gleibat Lafhouda intrusion is hosted by Archean gneiss and schist and not visibly associated with alkaline rocks. Metasomatized micaceous rocks occur locally at the margins of the carbonatite outcrop and were identified as glimmerite fenite type. Rare earth element (REE) and Nb mineralization is mainly linked to the associated IOA mineralization and is represented by monazite-(Ce) and columbite-(Fe) as major ore minerals. The IOA mineralization mainly consists of magnetite and hematite that usually contain large apatite crystals, quartz and some dolomite. Monazite-(Ce) is closely associated with fluorapatite and occurs as inclusions within the altered parts of apatite and along cracks or as separate phases near apatite. Monazite shows no zonation patterns and very low Th contents (<0.4 wt%), which would be beneficial for commercial extraction of the REE and which indicates monazite formation from apatite as a result of hydrothermal volatile-rich fluids. Similar monazite-apatite mineralization and chemistry also occurs at depth within the carbonatite, although the outcropping carbonatite is barren, suggesting an irregular REE ore distribution within the carbonatite body. The barren carbonatite contains some tiny unidentified secondary Nb-Ta-U phases, synchysite and monazite. Niobium mineralization is commonly represented by anhedral minerals of columbite-(Fe) which occur closely associated with magnetite-hematite and host up to 78 wt% Nb₂O₅, 7 wt% Ta₂O₅ and 1.6 wt% Sc₂O₃. This association may suggest that columbite-(Fe) precipitated by an interaction of Nb-rich fluids with pre-existing Fe-rich minerals or as pseudomorphs after pre-existing Nb minerals like pyrochlore. Our results most strongly suggest that the studied mineralization is economically important and warrants both, further research and exploration with the ultimate goal of mineral extraction.     

江西崇义铁木里碱长花岗岩中铌和稀土元素的富集机制

华南是我国重要的战略性矿产资源基地,以花岗岩相关的稀有和稀土金属成矿作用而举世瞩目。其中,铌的成矿作用一般与过铝质高分异花岗岩有关,稀土元素则随岩浆演化程度增强而富集程度降低,而江西铁木里含黑云母碱长花岗岩体同时富集铌和稀土元素,矿化组合极具特色。本文在详细的矿物岩相学研究基础上,利用电子探针、飞秒激光电感耦合等离子质谱对铌和稀土矿物进行了矿物地球化学分析,借此对铁木里碱长花岗岩中铌和稀土元素的富集机制进行探讨。铁木里岩体由肉红色含黑云母碱长花岗岩(r-G)和灰白色含黑云母碱长花岗岩(g-G)组成,发育暗色包体。r-G中的铌矿物主要为岩浆期形成的铌铁金红石,稀土矿物包括岩浆期形成的硅钛铈矿、独居石、磷灰石和热液期形成的独居石和氟碳(钙)铈矿。g-G中的铌矿物包括岩浆期形成的铌铁金红石和热液期形成的铌铁金红石、易解石、铌铁矿,稀土矿物包括岩浆期磷灰石和热液期磷灰石、独居石、氟碳(钙)铈矿。暗色包体为岩浆混合成因,内含磷灰石、独居石和零星的硅钛铈矿、金红石。矿物组合特征显示,铁木里碱长花岗岩中的铌和稀土元素经过了岩浆和热液两个时期的富集。应用金红石、磷灰石、绿泥石等矿物成分特征约束了岩浆-...     

Ferride geochemistry of Swedish precambrian iron ores

Chemical analysis for major and trace elements have been performed on 30 Swedish Precambrian iron ores and on some from Iran and Chile. The Swedish ores consist of apatite iron ores, quartz-banded iron ores, skarn and limestone iron ores from the two main ore districts of Sweden, the Bergslagen and the Norrbotten province. Some Swedish titaniferous iron ores were also included in the investigation. The trace element data show that the Swedish ores can be subdivided into two major groups: 1. orthomagmatic and exhalative, 2. sedimentary. Within group 1 the titaniferous iron ores are distinguished by their high Ti-contents. From the ferride contents of the Kiruna apatite iron ores, the ores are considered to be mobilization products of skarn iron ores from the Norbotten province.     

Geochemistry of Apatite from the Apatite-rich Iron Deposits in the Ningwu Region, East Central China

Four types of apatite have been identified in the Ningwu region.The first type of apatite is widely distributed in the middle dark colored zones(i.e.iron ores) of individual deposits.The assemblage includes magnetite,apatite and actinolite(or diopside).The second type occurs within magnetite-apatite veins in the iron ores.The third type is seen in magnetite-apatite veins and (or) nodules in host rocks(i.e.gabbro-diorite porphyry or gabbro-diorite or pyroxene diorite).The fourth type occurs within apatite-pyrite-quartz veins filling fractures in the Xiangshan Group.Rare earth elements (REE) geochemistry of apatite of the four occurrences in porphyry iron deposits is presented.The REE distribution patterns of apatite are generally similar to those of apatites in the Kiruna-type iron ores,nelsonites.They are enriched in light REE,with pronounced negative Eu anomalies.The similarity of REE distribution patterns in apatites from various deposits in different locations in the world indicates a common process of formation for various ore types,e.g. immiscibility.Early magmatic apatites contain 3031.48-12080×10~(-6) REE.Later hydrothermal apatite contains 1958×10~(-6) REE,indicating that the later hydrothermal ore-forming solution contains lower REE.Although gabbro-diorite porphyry and apatite show similar REE patterns,gabbro-diorite porphyries have no europium anomalies or feeble positive or feeble negative europium anomalies, caused both by reduction environment of mantle source region and by fractionation and crystallization(immiscibility) under a high oxygen fugacity condition.Negative Eu anomalies of apatites were formed possibly due to acquisition of Eu~(2+) by earlier diopsite during ore magma cooling. The apatites in the Aoshan and Taishan iron deposits yield a narrow variation range of ~(87)Sr/~(86)Sr values from 0.7071 to 0.7073,similar to those of the volcanic and subvolcanic rocks,indicating that apatites were formed by liquid immiscibility and differentiation of intermediate and basic magmas.     

新疆哈赞布拉克金铜矿成矿地质特征及成因探讨

哈赞布拉克金铜矿位于博罗科努金铜钼铅锌成矿带.矿化产于华力西中期中酸性侵入岩体内及与围岩接触带内,主要蚀变为围岩地层中的角岩化,闪长岩中的钾化、绢云母化、青盤岩化及含矿岩石中的硅化、碳酸盐化等,矿区发现Ⅰ、Ⅱ、Ⅲ号三个矿化带,以Ⅱ号矿化带规模最大,矿床为铜、金共生矿化,矿化成因类型为石英脉型、矽卡岩型、斑岩型,以石英脉型矿化为主,矿化主要受岩浆岩和构造控制,矿床为先期斑岩型矿化,伴矽卡岩型矿化,经后期热液改造叠加的石英脉型矿床.     

山东苍山王埝沟铁矿床地质特征及找矿方法探讨

王埝沟铁矿床为隐伏矿床,产于泰山岩群山草峪组地层中,发育2条主矿带,总体走向为280°-290°,平行展布,相向而倾,具不对称向斜构造特征。该铁矿床2条主矿带发育5个矿体,北翼矿带发育3个矿体,南翼矿带发育2个矿体,矿体呈层状、似层状产出,产状与地层产状一致。综合分析研究成矿地质条件及区域成矿理论,并充分利用地面高精度磁法剖面测量成果,二者有机结合的综合式找矿方法,是目前寻找深部沉积变质型“鞍山式”铁矿盲矿体行之有效的方法。     

大冶铁矿控矿构造研究及深部隐伏矿体定位预测

大冶铁矿主矿体分布于燕山期闪长岩与下三叠统大冶群大理岩和白云质大理岩接触断裂复合带,该接触带是大冶铁矿矿床的主要控矿构造.文章对矿区接触带控矿构造类型及其空间分布特征、接触带形态产状特征及其与成矿的关系、成矿定位机制等作了比较系统的阐述,预测矿区深部可新增铁矿资源量4000万t.     

Alteration paragenesis and mineral chemistry of the Tjårrojåkka apatite–iron and Cu (-Au) occurrences, Kiruna area, northern Sweden

The northern Norrbotten area in northern Sweden, is an important mining district and hosts several deposits of Fe-oxide Cu-Au-type. One of the best examples of spatially, and possibly genetically, related apatite–iron and copper–gold deposits in the region is at Tjårrojåkka, 50 km WSW of Kiruna. The deposits are hosted by strongly sheared and metamorphosed intermediate volcanic rocks and dolerites and show a structural control. The Tjårrojåkka iron deposit is a typical apatite–iron ore of Kiruna-type and the Tjårrojåkka copper occurrence shows the same characteristics as most other epigenetic deposits in Norrbotten. The host rock has been affected by strong albite and K-feldspar alteration related to mineralisation, resulting in an enrichment of Na, K, and Ba. Fe and V were depleted in the altered zones and added in mineralised samples. REE were enriched in the system, with the greatest addition related to mineralisation. Y was also mobile associated with albite alteration and copper mineralisation. The Tjårrojåkka iron and copper deposits show comparable hydrothermal alteration minerals and paragenesis, which might be a product of common host rock and similarities in ore fluid composition, or overprinting by successive alteration stages. Mineralogy and mineral chemistry of the alteration minerals (apatite, scapolite, feldspars, amphiboles, and biotite) indicate a higher salinity and Ba/K ratio in the fluid related to the alterations in the apatite–iron occurrence than in the copper deposit, where the minerals are enriched in F and S. The presence of hematite, barite, and in SO₄ in scapolite suggests more oxidising-rich conditions during the emplacement of the Tjårrojåkka-Cu deposit. From existing data it might be suggested that one evolving system created the two occurrences, with the copper mineralisation representing a slightly later product.     

青海省大柴旦青龙沟金矿床地质特征、找矿标志和找矿方向

根据野外实际地质资料及室内研究工作,对青龙沟金矿床的矿床地质特征、成矿机理及找矿标志进行了综合分析与归纳。深入地阐述了东矿区和西矿区的金矿化带及矿体特征,明确了找矿标志和找矿方向。研究认为,该矿床的成因类型应属于中-低温热液构造破碎带型金矿床,应向该矿区的NW和SE方向加强深部找矿的力度。     

老挝万象省爬立山（PHaLek）铁矿床地质特征及成矿作用分析

爬立山铁矿床位于长山褶皱带北西端,是长山成矿带内与岩浆作用有关的一个大型铁矿床。根据野外地质观察及室内对含矿岩体、赋矿围岩和矿石开展的岩相学和地球化学研究发现：与成矿作用有关的花岗质岩石属钙碱系列准铝质的I型花岗岩,成岩的构造环境为火山弧。矿区内发育致密块状磁铁矿、孔洞状赤铁矿、砂砾土状铁矿等3种铁矿石。结合岩（矿）石微量元素分析,认为爬立山铁矿具有复合成矿作用特征,主要可分为3个成矿阶段：早期以与华力西期岩浆侵入作用有关的接触交代成矿作用为主,形成矽卡岩型磁铁矿;其后,在褶皱造山后形成的断陷盆地中,由于火山喷发（溢）作用形成孔洞状熔岩型赤铁矿;最后随着新生代地壳抬升,发生表生物理化学风化成矿作用,形成如今的砂砾土状型铁矿。     

湖北张福山矿浆-热液过渡型矽卡岩铁矿蚀变矿化分带

湖北张福山铁矿属矿浆-热液过渡型矽卡岩矿床。蚀变矿化具有立体分带性(分五个带)。从矿浆贯入到热浪交代带是连续过渡的,成矿温度由高到低,矿石TFe/FeO的比值逐渐升高,CaO的含量由低变高,品位由高变低,蚀变强度逐渐增强,矿体与围岩由截然接触渐变为过渡关系。最后本文对矿床的成矿机制进行了探讨。     

海南石碌铁矿独居石的成因类型、化学定年及地质意义

海南石碌铁矿是我国最大的富赤铁矿矿床,同时伴生有钴、铜等多金属矿产。轴向北西-南东向的复式向斜是石碌铁、钴铜矿体的主要控矿构造,富铁矿和钴铜矿的形成与该褶皱变形及伴随的韧性剪切和高温塑性流动有着密切的关系。为获得该构造变形的年代学信息和证实构造变形对成矿物质的富集影响,本文开展了石碌铁矿近矿围岩—石碌群第六层透辉石透闪石岩中独居石的显微结构观察和电子探针化学Th-U-Pb定年(CHIME法)。显微结构观察发现独居石往往沿岩石面理定向分布,且具典型的球冠结构,表现为围绕独居石核部向外依次出现磷灰石、褐帘石、绿帘石同心环。电子探针分析结果表明这些独居石为Ce-La-Nd磷酸盐[(Ce,La,Nd,Th)PO4],具富钍独居石端元组分。ThO 2含量范围(0.78%~4.61%)、稀土特征以及独居石的产出特征均暗示了其为同构造变质成因。电子探针CHIME化学定年结果表明独居石的年龄变化范围为614~397Ma,并具有两个峰值年龄:即主峰值ca.455Ma和次峰值ca.564Ma。低的ThO 2(0.78%~1.65%),PbO(0.02%~0.04%)和CaO(0.50%~0.97%)含量,以及高的Th/U比值(23.06~53.11)暗示了构成ca.564Ma的独居石是早期剪切变形事件的产物。而在随后剪切变形过程中独居石在低角闪岩相变质条件下以及碱性变质流体诱导下发生了溶解-再沉淀,形成了具ca.455Ma年龄的补丁状成分区。该过程引起了U-Pb体系的局部重置,形成的独居石具有变化较大的ThO 2(0.92%~4.61%)、PbO(0.01%~0.08%)和CaO(0.28%~1.58%)含量范围以及Th/U值(24.83~52.86)。在剪切变形之后,早期变质成因的独居石在绿片岩相退变质作用过程中及富Ca、Fe、Si、Al流体参与的条件下,经不平衡反应形成了磷灰石-褐帘石-绿帘石球冠物,反应机制以独居石和球冠矿物间的元素扩散动力学为主。该反应暗示了REE、Y、Th等元素发生了迁移,并可能引起边部独居石的部分Pb丢失。结合华南的构造演化,年龄谱主峰值455Ma代表了与华南加里东造山运动有关的区域变质和动力变质作用事件年龄,是加里东运动在海南岛的响应;次峰值年龄564Ma对应着冈瓦纳泛非事件,暗示了华南在晚新元古代-早古生代与冈瓦纳大陆具有亲缘性,华南加里东运动引起陆内造山过程可能与冈瓦纳大陆的聚合碰撞事件有关。因此,晚新元古代-早古生代造山事件对海南岛构造演化历史具重要影响。此外,该构造运动使石碌群发生褶皱变形,伴随产生的变质流体使铁、钴铜成矿元素进一步活化和富集,对石碌铁、钴铜矿的富集有着重要影响。     

云南鹤庆炉坪铅多金属矿矿石矿物学特征及其地质意义

云南鹤庆炉坪铅多金属矿床是新发现的一个大型隐伏矿床, 位于北衙超大型金多金属矿床北部, 属北衙金多金属矿田斑岩-热液成矿体系的组成部分, 是该成矿体系中的新类型矿床。它是在充分研究区内基本地质条件, 对比北衙矿区的成矿特点, 认为在北衙向斜构造的轴部应该存在构造薄弱地带, 能够为万硐山正长斑岩成矿体系中的成矿流体运移提供通道和赋存空间, 同时结合良好的Pb-Au-Ag-Zn-Cu-As-Sb组合异常显示的观点指导下, 通过钻探验证而发现的铅多金属隐伏矿床。矿体沿中三叠统北衙组灰岩与下三叠统腊美组砂泥岩层间及中三叠统北衙组灰岩内层间破碎带产出; 矿石类型主要为氧化矿和混合矿, 部分为硫化矿, 其主金属元素为铅, 伴生有金、银、铁、锌等多种有用组分; 本文通过分析和总结该矿床的矿物学特征、有用组分的赋存状态及分布特征, 提出了开发利用该矿床应加强进一步开展相关研究工作的建议。     

桂北构造蚀变岩型金矿的发现及成矿规律研究

桂北地区金矿划分为石英脉型、石英细脉薄脉型和构造蚀变岩型金矿.不同级别剪切带构造控制着矿化集中区、矿床、矿体的分布,以及与矿脉形态、产状和矿化类型有着空间上的密切联系.具有上部石英脉型、中部石英细脉薄脉型、下部构造蚀变岩型金矿的矿化分带模式.桂北地区成矿条件好,与国内外许多大型超大型剪切带型金矿有类似成矿地质背景.研究认为,在桂北地区找矿应转变找矿思路,在老矿山深部及周边地区,具有大型构造蚀变岩型金矿找矿前景.