Genetic Types and Metallogenic Model for the Polymetallic Copper–Gold Deposits in the Tongling Ore District, Anhui Province, Eastern China

The Tongling ore district is one of the most economically important ore areas in the Middle–Lower Yangtze River Metallogenic Belt, eastern China. It contains hundreds of polymetallic copper–gold deposits and occurrences. Those deposits are mainly clustered(from west to east) within the Tongguanshan, Shizishan, Xinqiao, Fenghuangshan, and Shatanjiao orefields. Until recently, the majority of these deposits were thought to be skarn-or porphyry–skarn-type deposits; however there have been recent discoveries of numerous vein-type Au, Ag, and Pb-Zn deposits that do not fall into either of these categories. This indicates that there is some uncertainty over this classification. Here, we present the results of several systematic geological studies of representative deposits in the Tongling ore district. From investigation of the ore-controlling structures, lithology of the host rock, mineral assemblages, and the characteristics of the mineralization and alteration within these deposits, three genetic types of deposits(skarn-, porphyry-, and vein-type deposits) have been identified. The spatial and temporal relationships between the orebodies and Yanshanian intrusions combined with the sources of the ore-forming fluids and metals, as well as the geodynamic setting of this ore district, indicate that all three deposit types are genetically related each other and constitute a magmatic–hydrothermal system. This study outlines a model that relates the polymetallic copper–gold porphyry-, skarn-, and vein-type deposits within the Tongling ore district. This model provides a theoretical basis to guide exploration for deep-seated and concealed porphyry-type Cu(–Mo, –Au) deposits as well as shallow vein-type Au, Ag, and Pb–Zn deposits in this area and elsewhere.

Spatial-temporal Frame,Evolution and Mineralization of the Northern Qilian Metallogenic Province

Four metallogenic epochs occurred in different tectonic environments during theevolution of the Northern Qilian metallogenic province through the geological time. The Mid-dle Proterozoic metallogenic epoch witnessed the tectonic environment of crustal breakupcaused by mantle diapirism, in which ultramafic-mafic rocks were intruded along beep faultbelts and the superlarge Jinchuan magmatic Cu-Ni sulphide deposit was formed. In theMiddle-Late Proterozoic metallogenic epoch the crust was further broken to form anintracontinental rift, in which the Chenjiamiao style massive Cu-Fe sulphide deposits hosted bybasic volcanic tuff were formed in the lower volcano-sedimentary sequence, while the largesedex type Jingtieshan style Fe-Cu deposits were formed within the upper abyssal carbon-richargillaceous sedimentary sequence. The Early Palaeozoic saw the aulacogen environment, with-in which the Baiyinchang style superlarge massive base and precious metal sulphide depositshosted by quartz keratophyric tuff were formed in the Middle-Late Cambrian rifted island arcand the massive Cu-Zn sulphide deposits and magmatic chromite deposits associated with theophiolite suite were formed in the Early-Middle Ordovician, and the Honggou style massiveCu-Fe sulphide deposits hosted by spilite were formed in the Late Ordovician back-arc basinenvironment. In the Late Palaeozoic-Meso-Cenozoic, the metallogenic province went into anintracontinental orogenic stage characterized by compressive tectonic environment, in whichthere occurred carbonate-quartz vein type and tectono-alteration gold deposits associated withductile-shear structures.

Types of uranium deposits in central Zhuguang Mountains in Hunan Province,South China and their metallogenic regularity and prospecting directions

The central Zhuguang Mountains in Hunan Province is located at the junction of the three provinces,namely Hunan,Jiangxi,and Guangdong,where the famous Lujing uranium ore field lies.The uranium deposits occurring in this area are all granite-related and they can be divided into three types,namely endogranitic ones,perigranitic ones,and contact zone types.The endogranitic uranium deposits are mainly controlled by the structural alteration zones developing within granites,with fragmentation,hematitization,and alkali metasomatism as their main mineralization characteristics.The perigranitic uranium deposits are mainly produced in the carbonaceous,siliceous,and argillaceous composite layers of epimetamorphic rocks and are controlled by fractured zones formed due to interlayer compression.The contact zone type uranium deposits mainly occur in the contact parts between the granites and favorable horizons.They have developed in favorable sections where multiple sets of structures are combined and intersected.The main metallogenic regularities of uranium in the central Zhuguang Mountains are as follows.The basic conditions for the uranium mineralization in this area include the framework consisting of regional deep large faults and their associated multi-set multi-direction favorable metallogenic structures,multi-cycle and multi-stage uranium-rich rock masses,and uranium-rich folded basement.Meanwhile,the uranium deposits in this area are closely related to granites in terms of genesis and space and they are formed in different structural parts subject to the same metallization.Furthermore,based on the summary of the characteristics and regularities of uranium mineralization in this area,the controlling factors of different types of uranium deposits in the area were explored and six metallogenic target areas were predicted.All these will provide references for the exploration of uranium deposits in this area.

Research Progress of the Mineralization of Carbonate-Hosted Pb-Zn Deposits in the Sichuan-Yunnan-Guizhou Pb-Zn Metallogenic Province, Southwest China

The Sichuan-Yunnan-Guizhou （SYG） Pb-Zn metallogenic province in the western Yangtze Block, is a key component of the low-temperature metallogenic domain in South China. In this area, more than 400 Pb-Zn deposits have been discovered, and the total proven reserves are up to 260 million tons with lead and zinc grade reaching 10%, even up to 30%.

METALLOGENIC EVOLUTION AND MODEL OF MANZHOULI-XINBAERHU METALLOGENIC PROVINCE

This area is a superlarge potentiality metallogenic province of multimetal resource,belonging to Ergun accretionary fold system of early Caledonian.The regional basement(Neoproterozoic-Lower Cambrian Series)is the outer extent of the Siberian craton margin,and the metallization in this area was affected intensely by Pacific plate tectonics.The NE trending Ergun-Hulun deep-seated fracture controls the giant volcano-magmatic activty and mineralization in this area.NW cross trending tenso-shear fractures control the formation of ore cluster in this area.The major types of ore deposits in this area are porphyry type,subvolcanic hydrothermal vein type and skarn type.They are the products of different depths and environments as genetically-related,which can be collectively regarded as porphyry copper-multimetal metallogenic series.

Metallogenic model and prognosis of the Shuiyindong super-large strata-bound Carlin-type gold deposit, southwestern Guizhou Province, China

The Shuiyindong deposit is one of the largest (more than 100 tonnes of Au) and highest grade (more than 7×10-6-10×10-6), strata-bound Carlintype gold deposits in southwestern Guizhou Province, China. The deposit is controlled by both structure and favorable lithology. It is situated near the axis of the striking Huijiabao anticline and is hosted in bioclastic limestone of the Permian Longtan Formation. Gold mineralization occurred under low temperature with Th of 220℃± and is closely associated with decarbonation, silicification, sulfidation and dolomitization. The deposit has a characteristic elemental assemblage of Au-As-Hg-Tl. Studies of geochemistry and isotope compositions indicated that the ore-bearing materials and fluids of the gold deposit mainly originated from a plutonic source, and possess a mixing feature with the strata matter during transportation from mantle to crust. Fluid inclusions in vein quartz from the gold deposit are rich in volatile flux, indicating that metallogenic fluid is an overpres-sured one. The activity and geothermal state of the Earth's crust in the long period of time are favorable for the formation of overpressured fluids in a large area, and extensive structures would drive the fluids into ore-forming sys-tem and make gold deposits formed. The complexity of structural movement in the upper crust of southwestern Guizhou Province resulted in complicated gold mineralization. Through metallogenic prognosis and exploration, the proven reserves of the deposit increased by tens of tonnes of Au and the deposit has become a super-large strata-bound Carlin-type gold deposit.

Deep gold mineralization features of Jiaojia metallogenic belt,Jiaodong gold Province:Based on the breakthrough of 3000 m exploration drilling

Recently,continuous breakthroughs have been made about deep gold prospecting in the Jiaodong gold province area of China.Approximately 5000 t of cumulative gold resources have been explored in Jiaodong,which has thus become an internationally noteworthy gold ore cluster.The gold exploration depth has been increased to about 2000 m from the previous<1000 m.To further explore the mineralization potential of the Jiaodong area at a depth of about 3000 m,the Shandong Institute of Geological Sciences has drilled an exploratory drillhole named“Deep drillhole ZK01”to a depth of 3266 m.Hence,as reported herein,the mineralization characteristics of the Jiaojia metallogenic belt have been successfully documented.ZK01 is,to date,the deepest borehole with an gold intersect in China,and constitutes a significant advance in deep gold prospecting in China.The findings of this study further indicate that the depth interval of 2000 m to 4000 m below the ground surface in the Wuyi Village area incorporates 912 t of inferred gold resources,while the depth interval of 2000 m to 4000 m below the surface across the Jiaodong area possesses about 4000 t of inferred gold resources.The Jiaojia Fault Belt tends to gently dip downward,having dip angles of about 25°and about 20°at vertical depths of 2000 m and 2850 m,respectively.The deep part of the Jiaojia metallogenic belt differs from the shallow and moderately deep parts about fracturing,alteration,mineralization,and tectonic type.The deep zones can generally be categorized from inside outward as cataclastic granite,granitic cataclasite,weakly beresitized granitic cataclasite,beresitized cataclasite,and gouge.These zones exhibit a gradual transitional relation or occur alternately and repeatedly.The mineralization degree of the pyritized cataclastic granite-type ore in the deep part of the Jiaojia metallogenic belt is closely related to the degree of pyrite vein development;that is,the higher the pyrite content,the wider the veins and the higher the gold grade.Compared to the shallow gold ores,the deep-seated gold ores have higher fineness and contain joseite,tetradymite,and native bismuth,suggesting that the deep gold mineralization temperature is higher and that mantle-sourced material may have contributed to this mineralization.ZK01 has also revealed that the deep-seated ore bodies in the Jiaojia metallogenic belt are principally situated above the main fracture plane(gouge)and hosted within the Linglong Granite,contradicting previous findings indicating that the moderately shallow gold ore bodies are usually hosted in the contact zone between the Linglong Granite and Jiaodong Group or meta-gabbro.These new discoveries are particularly significant because they can help correct mineralization prospecting models,determine favorable positions for deep prospecting,and improve metallogenic prediction and resource potential evaluation.

The Late Cretaceous Crustal Magmatism of the Geza Arc Metallogenic Belt in Yunnan Province,and Zircon Ages and Hf Isotopic Evidence of the Porphyry Cu-Mo Mineralization

Objective The Geza arc in Yunnan Province,located in the southern Yidun arc,is an important part of the Sanjiang tectonic-magmatic belts in southwestern China and is a newly discovered copper polymetallic ore-concentrating district.Recent studies show that the newly discovered Yanshanian porphyry Cu-Mo polymetallic mineralization superimposed in the Indosinian porphyry copper belt in this area.

ANALYSIS OF TECTONIC EVOLUTION AND MAJOR Cu (Au) POLYMETALLIC METALLOGENIC SERIES IN NORTHEAST JIANGXI PROVINCE

Northeast Jiangxi Province is an important area in China with closely packed Cu (Au) polymetallic metallization. The tectonic action of this area is complex and violent, and three stages of geotectonic development of the Earth’s crust have taken place there since the Jingning Movement.Every stage formed a distinctive ore-bearing formation, and the three stages formed three suits of Cu(Au) polymetallic metallogenic series with different features. They are the Proterozoic dynamometamorphic metallogenic series, the Paleozoic exhalation-sediment metallogenic series and the Meso-Cenozoic volcano-subvolcanic metallogenic series.

Delineation of Haigou gold metallogenic province and its metallogenic prospection

Based on the accumulated data for the gold deposits in the central Jilin Province in recent years and our understanding of the gold metallogenic province,the Haigou gold metallogenic province is delineated and the denudation degree of gold deposits in this province is discussed. The potential and the ore-searching direction of the province are also considered. The Haigou gold metallogenic province occurs as an independent province with low denudation degree and high ore-producing potential. Regional fault belts and small basic intrusions are two ore-constrains and could serve as the ore-searching indictors in the province.

“Structure-Lithologic-Fluid” Metallogenic Coupling of the Wuzhishan Lead-Zinc Deposit in Puding, Guizhou Province

1 Introduction The Wuzhishan lead-zinc ore-concentrated area in Puding is located in the east of the Sichuan,Guizhou and Yunnan lead-zinc metallogenic domain,with the Youjiang-Nanpan River metallogenic province to the

The Geochemical Characteristics and Metallogenic Mechanism of the Daliangzi Pb-Zn Deposit in Sichuan Province

1 Introduction Daliangzi large-sized Pb-Zn deposit,located in the Western Margin of Yangtze Plate,is typical Pb-Zn deposit in the sichuan-yunnan-guizhou polymetallic metallogenic belt.Ore bodies are hosted in Sinian

Metallogenic Prediction of the Peripheral Areas of the Xiyi Concealed Lead-Zinc Deposit in Baoshan City, Yunnan Province

The newly-discovered Xiyi lead-zinc deposit is a large deposit located in the north central Baoshan block of the southern Sanjiang metallogenic belt section, Southwest China.The surface of the deposit is mainly covered by eluvial-deluvial lateritic layer, without any mineralized outcrops. The main concealed orebody V3 is buffed in the depth of 300-500m. The orebodies are controlled by certain stratigraphic horizons, and most are cut by strata with a high angle, while a few occur along the strata. The direct wall rocks are calcisiltite, calclithite, bioclastic calcarenite,

Preliminary Study on the Metallogenic System of Mafic Large Igneous Provinces(MLIPs)

Large igneous provinces（LIPs）generally refer to the different types of the igneous rocks,which intrude in a short time,ranging in area from 50000 to 100000 km;（Sheth,2007;Bryan et al.,2008）.While the mafic large

The Dynamic Mechanisms for the Formation of Primary Metal Zoning of Cassiterite-Sulfide Deposits in the Gejiu Metallogenic Province, Yunnan

Copper and tin in cassiterite-sulfide deposits of the Gejiu metallogenic province are intimately associatedand show peculiar primary metal zoning. The authors made use of computer techniques to simulatenumerically the zoning of these ore deposits. The study shows that the regular spatial zoning probably resultedfrom the succession of multiple, intermittent and pulsatory mineralizations, The successive transports with di-verse velocities along channelways of the ore-forming solutions, taking place under conditions of definite dif-ference between metal concentrations, in solutions and wallrocks, followed by differential deposition, consti-tute possible dynamic mechanisms for the primary metal zoning.

China's First Independent Cobalt Deposit and its Metallogenic Mechanism:Evidence from Fluid Inclusions and Isotopic Geochemistry

The Tuolugou cobalt deposit is the first independent large-scale Co- and Au-bearing deposit discovered in northwestern China. It is located in the eastern Kunlun orogenic belt in Qinghai Province, and occurs conformably in low-grade metamorphic volcano-sedimentary rock series with well-developed Na-rich hydrothermal sedimentary rocks and typical hydrothermal sedimentary ore fabrics. Fluid inclusions and isotopic geochemistry studies suggest that cobalt mineralizing fluid is dominated by NaCI-H20 system, accompanied by NaCI-CO2-H20-N2 system responsible for gold mineralization. Massive, banded and disseminated pyrite ores have similar compositions of He and Ar isotopes from the mineralizing fluid, with 3He/4He range between 0.10 to 0.31Ra （averaging 0.21Ra）, and 4~Ar/36Ar between 302 and 569 （averaging 373）, which reflects that Co mineralizing fluids derived dominantly from meteoric water deeply circulating. ~34S values of pyrite approaches to zero （~34S ranging from -4.5%o to ＋1.5%o, centering around -1.8%o to -0.2%o）, reflecting its deep source. Ore lead is characterized by distinctly high radiogenesis, with 2~6pb/2~4pb〉19.279, 2~7pb/2~4pb〉15.691 and 2~spb/2~4pb〉39.627, and its values show an increase trend from country rocks, regional Paleozoic volcanic rocks to ores. This may have suggested that high radiogentic ore Pb derived mainly from country rocks by leaching meteoric water-dominated hydrothermal fluid during its circulation at depth. Cobalt occurs mainly in sulfide phase （such as pyrite）, but cobalt enrichment, and presence and increasing contents of Co-bearing minerals have a positive correlation with metamorphic degree. The Tuolugou deposit and other typical strata-bound Co-Cu-Au deposits have striking similarities in the geological features and metallogenic pattern of primary cobalt. All of them are syngenetic hydrothermal exhalative sedimentation in origin.

Composite Metallogenic Systems in the Weihai Area of Shandong and Evolution of Continental Dynamic Regimes

Based on 9 sheets of 1：50,000-scale regional geological survey and guided by the theory of metallogenic systems and integrated analyses of the structural and metallogenic features, this paper hereby puts forward the composite metallogenic systems of the Weihai area, Shandong Province, aiming at solving the problems on the origins and ore-controlling structures of the numerous deposits in the area. Its scientific significance is reflected in the following three aspects： （1） The basic features of the composite metallogenic systems can be recognized, which consist of two types： the Proterozoic metamorphic-hydrothermal metallogenic system and the Mesozoic magmatic-hydrothermal metallogenic system （i.e. the Indosinian-early Yanshanian contact metasomatic metallogenic series and the mid-late Yanshanian magmatic-hydrothermal metallogenic series）. The two series display arcuate and NW-right lateral arrangements and a N-S parallel zonal distribution respectively, with the corresponding mineral assemblages being Au＋Ag＋Pb＋Zn, etc.; and Cu＋Mo＋Fe, Au＋Ag＋Cu＋Pb- Zn＋Mo＋Co-Ni＋sulfides＋silicides＋K-feldspar, etc. （2） The composite metallogenic systems may be used to interpret the complicated genetic relations of the deposits. Through analyses of the relations between the three main metallogenic intervals and their corresponding source rock series （the Jingshan and Rongcheng groups; the Wendong super-unit and the early-middle Yanshanian Weideshan super-unit; and the mid-late Yanshanian Weideshan and Laoshan super-units） as well as a case study of the Fanjiabu gold deposit, we have distinguished the consanguinity between the contact metasomatic （skarn-type） metallogenic series and the magmatic-hydrothermal metallogenic series as well as the noncognate superposition between the two and the metamorphic-hydrothermal metallogenic system. （3） The composite metallogenic systems are easily related to the evolution of continental dynamic regimes. The formation of the metamorphic-hydrothermal metallogenic system has undergone transformations of three different types of tectono-dynamic regimes from extension→compression→ shearing; that of the contact metasomatic （skarn-type） metallogenic system from compression→extension→compression; and that of the magmatic-hydrothermal metallogenic system from extension →subductive compression of the Pacific Plate. The evolutions of the three types are all attributed to the opening-closing or divergence-convergence of the paleocontinent, and all their mineralization corresponds to the interval of transformation from the end of convergence to early integration of the Weihai paleocontinent. All these will benefit our deeper study of the dynamics of continental metallogenic processes.

Geochemical characteristics and genetic type of a lithium ore (mineralized) body in the central Yunnan Province, China

Lithium ore (mineralized) bodies in the area A of central Yunnan Province belong to a sedimentary-type, which are controlled by stratum. The studied ore (mineralized) body mainly occurs in the Middle Permian Liangshan Formation. This work described the morphology, structures, main ore types and geochemical characteristics of this ore body in detail, and discussed the ore-forming material source, occurrence state of lithium and the formation mechanism of lithium ores to clarify the prospecting marks. In the further exploration, comprehensive evaluation of the lithium resources of known bauxite ore bodies in central Yunnan Province should be strengthened, and the exploration of hidden lithium ore bodies should be intensified in order to discover more large and super-large lithium orebodies, which will fill the gap of the national demand for lithium resources, and promote the national defense construction and new energy industry development.

Study on the ore-forming and ore-controlling structure of the Mujicun Cu (Mo) ore deposit, Hebei Province, China

The Mujicun Cu (Mo) ore deposit at Laiyuan, Hebei Province, is a currently proven large-sized Cu (Mo) polymetallic ore deposit and it is located in the second-ordered fault depression basin of the ditachment belt on the hanging-wall on the western side at the juncture of the Laiyuan dumbell-shaped complex in the northern part of the Fuping mantle-branch structure. Metallogenesis is controlled by diorite porphyrite in intrusive relation with the fault depression basin and other relevant fault structure systems and intenstive wall-rock alteration zones. This study, in conjunction with the most recent exploration data, analyzed the geological background of metallogenesis of this deposit, summaried the geological characteristics of typical ore deposits, determined the alteration zonation of the deposit, investigated regional metallogenesis and the genesis of typical ore deposits, discussed the regional ore-forming and ore-controlling structures, and generalized the regional ore-controlling model and metallogenic model of the deposit. It is considered that the Mujicun porphry Cu (Mo) deposit, the Tieling, Futuyu, Xiaoligou and other skarn-type Fe-Cu deposits and the He'ergou hydrothermal-type Pb-Zn-Ag deposit jointly constitute a three-in-one polymetallic orefield, with the characteristics of typical metallogenic series.

华南中生代陆内成矿作用

陆内成矿机制是全球性科学难题。华南陆块中生代成矿大爆发,成矿作用远离活动大陆边缘,形成西部金锑铅锌低温成矿省和东部钨锡多金属高温成矿省,是研究陆内成矿的理想场所。因为空间上的分离,两个成矿省长期被认为是互为独立的体系。研究发现,西部低温成矿(230~200 Ma、160~130 Ma)与东部高温成矿时代一致并显示类似的地球化学指纹,印支期陆内造山和燕山期软流圈上涌是其共有成矿驱动机制,两个成矿省是具有成因联系的整体,共同构成面状展布的巨型多金属陆内成矿区;成矿后华南从西向东剥蚀程度的增强控制了目前近地表矿西部低温、东部高温的空间分布格局,低温成矿省东部区域的深部可能存在高温钨锡多金属矿床。在此基础上,建立了定位于陆内岩石圈先存薄弱区、陆壳供给矿源、高低温矿并重、成矿面状展布从而明显区别于板块边缘成矿机制的华南陆内成矿新理论。