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Iran hosts more than 350 Precambrian to Cenozoic sediment-hosted Zn-Pb±Ba and barite-sulfide deposits, including shale-hosted massive sulfide (SHMS, also called SEDEX) and Irish-type and Mississippi Valley-type (MVT) mineralization, and barite is a common mineral in these deposits. In the SHMS deposits, barite is typically found as fine-grained disseminations in thin laminae. In these deposits, the sulfide laminae often occur as diagenetic replacements and as bands containing authigenic and diagenetic barite and pyrite framboids. In the Irish-type Zn-Pb-Ba and stratabound barite-sulfide deposits, barite exhibits various textures, including fine-grained disseminated barite, banded zebra textures, veins, and massive barite lenses. In some of the giant Irish-type deposits, as well as in the stratabound barite-sulfide mineralization, the main stratabound sulfide ore is developed within a barite envelope and is characterized by the replacement of barite and pyrite by chalcopyrite, galena, and sphalerite. In the MVT deposits, the formation of barite is often related to dolomitization, and sulfide mineralization involves the replacement of the dolomitized carbonate rocks, as well as associated barite. Fluid inclusion studies on the Irish-type deposits indicate that the temperatures and salinities of the sulfide-forming fluids are higher compared to those of the barite-forming fluids. Fluid inclusion analyses of coarse-grained barites from Irish and MVT deposits reveal their hydrothermal origin. The δ3⁴S values of sulfide minerals (pyrite, sphalerite, and galena) in Irish-type deposits exhibit a broad range of low values (mostly −28 to +5‰), primarily revealing a process of bacterial sulfate reduction (BSR). However, the textures (replacement, colloform, and banded) and more positive sulfur isotope values (+1 to +36‰) in the SHMS Zn-Pb deposits suggest that bacterial sulfate reduction (BSR) plays a less significant role. We suggest that thermochemical sulfate reduction (TSR) connected to the direct replacement of barite plays a more relevant role in providing sulfur for the sulfide mineralization in the SHMS, barite-sulfide, and MVT deposits. Based on the textual evidence, sulfur isotopic data, and fluid inclusion studies, barite has been identified as a key controller for the subsequent Zn-Pb mineralization by providing a suitable host and significant sulfur contribution in the sediment-hosted Zn-Pb and stratabound barite-sulfide deposits. This implies that diagenetic barite might be a precursor to all types of sediment-hosted Zn-Pb mineralization. [ABSTRACT FROM AUTHOR]

Iran hosts more than 350 Precambrian to Cenozoic sediment-hosted Zn-Pb±Ba and barite-sulfide deposits, including shale-hosted massive sulfide (SHMS, also called SEDEX) and Irish-type and Mississippi Valley-type (MVT) mineralization, and barite is a common mineral in these deposits. In the SHMS deposits, barite is typically found as fine-grained disseminations in thin laminae. In these deposits, the sulfide laminae often occur as diagenetic replacements and as bands containing authigenic and diagenetic barite and pyrite framboids. In the Irish-type Zn-Pb-Ba and stratabound barite-sulfide deposits, barite exhibits various textures, including fine-grained disseminated barite, banded zebra textures, veins, and massive barite lenses. In some of the giant Irish-type deposits, as well as in the stratabound barite-sulfide mineralization, the main stratabound sulfide ore is developed within a barite envelope and is characterized by the replacement of barite and pyrite by chalcopyrite, galena, and sphalerite. In the MVT deposits, the formation of barite is often related to dolomitization, and sulfide mineralization involves the replacement of the dolomitized carbonate rocks, as well as associated barite. Fluid inclusion studies on the Irish-type deposits indicate that the temperatures and salinities of the sulfide-forming fluids are higher compared to those of the barite-forming fluids. Fluid inclusion analyses of coarse-grained barites from Irish and MVT deposits reveal their hydrothermal origin. The δ3⁴S values of sulfide minerals (pyrite, sphalerite, and galena) in Irish-type deposits exhibit a broad range of low values (mostly −28 to +5‰), primarily revealing a process of bacterial sulfate reduction (BSR). However, the textures (replacement, colloform, and banded) and more positive sulfur isotope values (+1 to +36‰) in the SHMS Zn-Pb deposits suggest that bacterial sulfate reduction (BSR) plays a less significant role. We suggest that thermochemical sulfate reduction (TSR) connected to the direct replacement of barite plays a more relevant role in providing sulfur for the sulfide mineralization in the SHMS, barite-sulfide, and MVT deposits. Based on the textual evidence, sulfur isotopic data, and fluid inclusion studies, barite has been identified as a key controller for the subsequent Zn-Pb mineralization by providing a suitable host and significant sulfur contribution in the sediment-hosted Zn-Pb and stratabound barite-sulfide deposits. This implies that diagenetic barite might be a precursor to all types of sediment-hosted Zn-Pb mineralization.

The Middle and Lower Reaches of the Yangtze River metallogenic belt (MLYMB) is one of the most important Fe‐Cu polymetallic belts in China. However, the mechanism and deep geodynamical process for the formation of this belt are still controversial. Here, we obtain the crustal and the uppermost mantle structures using ambient noise data from a dense seismic profile. A low velocity zone is revealed beneath the Moho of MLYMB, interpreted as the source of the deep mineralization materials. In addition, a low velocity layer (LVL) and a high velocity layer (HVL) are observed in the crust of the southern segment of the profile. The LVL is interpreted as a tectonic detachment layer between the upper and the lower crust, and the HVL is interpreted as the aggregation zone for mineralizing melts or crystallized magma chambers. Based on the observed velocity features, we propose a three‐stage model for the formation of ore deposits in MLYMB. Our model suggests that an upwelling of asthenosphere triggered by the delamination of a previously thickened lithosphere leads to the partial melting of upper mantle rocks, which eventually ponders under the Moho. The magma then infiltrates through the ductile lower crust and reaches a depth of ∼7–13 km, forming a minerals‐enriched magma chamber. Minerals‐rich hot fluids originating from the magma chamber continue to move upward along the pre‐existent faults and the minerals finally precipitate in dense veinlets when reaching shallow depths, forming the ore deposits in and around the MLYMB. Plain Language Summary: The formation of large‐scale mineral deposits is closely related to the lithosphere structure. The Middle and Lower Reaches of the Yangtze River metallogenic belt (MLYMB) is an ideal place to study the mineral system, as it is one of the most important Fe‐Cu polymetallic metallogenic belts in Eastern China and contains more than 200 ore deposits. Yet the mechanism and deep geodynamical process for the formation of this belt are still controversial. In this study, we construct a high‐resolution seismic model of the crust and the uppermost mantle using ambient noise data from a dense seismic profile. Our result reveals velocity features closely related to the metallogenic process in this region. Based on the observed velocity features, we propose a three‐stage model for the formation of the ore deposits in MLYMB, which is of great importance for the development of "mineral system" approaches to the exploration of minerals worldwide. Key Points: We obtain a fine Vs structure of the crust and uppermost mantle beneath the MLYMBWe observe velocity features closely related to the metallogenic process of MLYMBWe propose a three‐stage metallogenic process for the origin of the MLYMB [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Geoscientica Sinica is the property of Acta Geoscientica Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

China is rich in abundant lithium resources characterized by considerable reserves and a concentrated distribution of metallogenic zones or belts, with proven reserves of 4046.8×103 t (calculated based on Li2O) by 2021. China is also a big consumer of lithium. By 2019, China ’s lithium consumption in the battery sector alone had reached 99×103 t, with an average annual growth rate of nearly 26%. China has become the world ’s largest importer of lithium resources, showing a severely unbalanced relationship between supply and demand for lithium resources. Therefore, there is an urgent need for the prospecting, exploitation, and study of lithium resources in China. This study collected, organized, and summarized the data on the major lithium deposits in China, analyzed and compared the spatial-temporal distribution patterns, geological characteristics, and metallogenic regularity of these lithium deposits, and summarized the prospecting and research achievements over the last decade. The major lithium deposits in China are distributed in provinces and regions such as Qinghai, Jiangxi, Sichuan, Tibet, and Xinjiang. These deposits are mostly small in scale. According to different genetic types, this study divided lithium deposits into granitic pegmatite type, granite type, saline lake brine type, underground brine type, and sedimentary type, as well as new types including hot spring type and magmatic-hydrothermal type, and summarized the characteristics and key metallogenic factors of these different types of deposits. Sixteen metallogenic prospect areas of lithium deposits were delineated according to the deposit types and the distribution patterns of metallogenic belts. The paper introduced the research progress in major metallogenic models and lithium extraction techniques made over the past decade. Based on the comprehensive analysis of the prospecting potential of lithium deposits, the authors concluded that the future prospecting of lithium resources in China should focus on lithium metallogenic belts, the deep and peripheral areas of currently determined large-scale pegmatite-type lithium deposits, geophysical-geochemical anomalous areas with mineralization clues, and areas with developed large-scale low-grade associated granite-type and sedimentary lithium resources. The study aims to serve as a guide for the future prospecting of lithium deposits in China.©2022 China Geology Editorial Office.

Crustal structure and fluid or melt originating in the deep crust and mantle are critical in regional magmatic mineral systems. However, the crustal structure and the processes that entrain and focus fluids from a deep-source region to a metallogenic belt remain relatively undisclosed. We present a magnetotelluric (MT) study of the eastern Qimantagh Metallogenic Belt (QMB) in the northern Tibetan Plateau. Data from 33 MT stations in two sections and 7 dispersed stations are acquired using a surface electromagnetic prospecting (SEP) system in frequency band ranges from 320 Hz to 0.00034 Hz. Data are converted by Bostick conversion and two-dimensional (2D) nonlinear conjugate gradient inversion. Our MT results reveal the geoelectrical crustal structure of the QMB, which consists of a southern low-resistivity domain that reflects the Kumukuri rift, a high-resistivity middle domain that represents the southern QMB in the central Kunlun belt, and a northern low-resistivity domain that covers the northern QMB and southwestern Qaidam block. We present a comprehensive tectonic and geophysical model of QMB based on the MT interpretation and geological analysis. We infer the high-resistivity domain as a reflection of a rigid crust and detached lithospheric mantle, this belt separate the QMB into northern and southern QMB. Most of the mineral deposits are found in the northern low-resistivity domain of QMB. Our study and findings provide an understanding of the tectonic evolution of the northern Tibetan Plateau, the crustal structure that controls the temporal and spatial distribution of magmatic rocks, and the geological signature associated with mineral deposits. [ABSTRACT FROM AUTHOR]

A 3-D lithospheric resistivity model is obtained with 699 MT stations. The upper-mantle low-resistivity anomalies beneath the eastern SCB show a spatial distribution that is gradually shallowing from south to north, probably indicating that the asthenospheric materials are upwelling from south to north, corresponding with the changing progressively of magma and metallogenic activities. [Display omitted] • The 3-D lithospheric resistivity structure of the lithosphere in South China is obtained by inverting 699 MT stations. • The resistivity structure and disposition of four metallogenic belts in the South China Block are outlined. • The upper-mantle low-resistivity anomalies show a spatial distribution of gradual shallowing, indicating the asthenospheric upwelling from south to north. The South China Block (SCB) is located at the junction of the Pacific, Eurasian, and Indo-Australian plates. Their interaction led to large-scale multi-stage mineralization in the SCB during the Mesozoic. Several regional ore-concentration areas, such as the Middle-Lower Yangtze Metallogenic Belt (MLYMB), the Qinzhou-Hangzhou Metallogenic Belt (QHMB), the Wuyishan Metallogenic Belt (WYMB), and the Nanling Metallogenic Belt (NLMB) were formed during this process. However, the dominant mineral types of these metallogenic belts are different. To study the deep mechanisms of the different metallogenic types developed in the same tectonic background at almost the same period, the magnetotelluric sounding (MT) data from 691 sites located mainly within the eastern SCB are employed to obtain a regional lithospheric 3-D resistivity model. It could be concluded from the resistivity model that deep low-resistivity anomalies and mantle upwelling channels mainly controlled almost all the Mesozoic deposits. Large-scale low-resistivity bodies extend from the crust to the upper mantle beneath the MLYMB and the QHMB, interpreted as channels of mantle-derived magma and melts/fluids containing metallogenic elements upwelling. However, the MLYMB and the QHMB have different upper crustal ore-conducting and ore-controlling structures, thus forming porphyry copper and copper-bearing tungsten deposits. Small-scale low-resistivity anomalies are invading the high-resistivity crust in the NLMB. And remelting the upper crust, mixing, and intrusion of crust-source magma, enriching tungsten-tin elements near the NLMB. Larger-scale low-resistivity anomalies exist deep in the WYMB, remelting the lower crust and resulting in the formation of porphyry copper in it. Significantly, the upper-mantle low-resistivity anomalies beneath the eastern SCB show a spatial distribution that is gradually shallowing from south to north, probably indicating that the asthenospheric materials are upwelling from south to north, corresponding with the changing progressively of magma and metallogenic activities. We propose that the lithospheric delamination and asthenospheric upwelling caused by the far-field effects of the Paleo-Pacific Plate subduction are the sources of solid magmatic activities and related metallogeny. [ABSTRACT FROM AUTHOR]

The 1∶1000000 geochemical mapping of Zambia provides catchment sediment geochemical data for 58 elements including Au from 746 sediment samples at 736 sampling sites, corresponding to a sampling density of about one site per 1000 km2. Under strict quality control using field duplicates, certified reference materials, and analytical replicate samples, the Au was determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The detection limit of Au was 0.20 × 10−9. The 95% range (2.5%–97.5%) of Au concentrations was from 0.24 × 10−9 to 1.36 × 10−9, and the median value was 0.40 × 10−9. The most noticeable Au distribution patterns shown on the map are mainly located between Lusaka and Ndola (Lufilian Arc Belt). In addition, several high Au value areas occurred in Mansa, Muyombe, Chipata, and Livingstone. The spatial distribution patterns of Au in tectonic units, drainage basins, and geomorphological landscapes could be related to the Lufilian Arc Belt and Bangweulu Block. The Au concentrations show metallogenic belts between Muyombe and Mbala areas, between Mansa and Ndola areas, and between Lusaka and Kasempa areas.© 2022 China Geology Editorial Office.

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.

Abstract Crustal architecture strongly influences the development and emplacement of mineral zones. In this study, we image the crustal structure beneath a metallogenic belt and its surroundings in the Bayankhongor area of central Mongolia. In this region, an ophiolite belt marks the location of an ancient suture zone, which is presently associated with a reactivated fault system. Nearby, metamorphic and volcanic belts host important mineralization zones and constitute a significant metallogenic belt that includes sources of copper and gold. However, the crustal structure of these features, and their relationships, are poorly studied. We analyze magnetotelluric data acquired across this region and generate three-dimensional electrical resistivity models of the crustal structure, which is found to be locally highly heterogeneous. Because the upper crust ( 1000 Ωm), low-resistivity (

Crustal structure and fluid or melt originating in the deep crust and mantle are critical in regional magmatic mineral systems. However, the crustal structure and the processes that entrain and focus fluids from a deep-source region to a metallogenic belt remain relatively undisclosed. We present a magnetotelluric (MT) study of the eastern Qimantagh Metallogenic Belt (QMB) in the northern Tibetan Plateau. Data from 33 MT stations in two sections and 7 dispersed stations are acquired using a surface electromagnetic prospecting (SEP) system in frequency band ranges from 320 Hz to 0.00034 Hz. Data are converted by Bostick conversion and two-dimensional (2D) nonlinear conjugate gradient inversion. Our MT results reveal the geoelectrical crustal structure of the QMB, which consists of a southern low-resistivity domain that reflects the Kumukuri rift, a high-resistivity middle domain that represents the southern QMB in the central Kunlun belt, and a northern low-resistivity domain that covers the northern QMB and southwestern Qaidam block. We present a comprehensive tectonic and geophysical model of QMB based on the MT interpretation and geological analysis. We infer the high-resistivity domain as a reflection of a rigid crust and detached lithospheric mantle, this belt separate the QMB into northern and southern QMB. Most of the mineral deposits are found in the northern low-resistivity domain of QMB. Our study and findings provide an understanding of the tectonic evolution of the northern Tibetan Plateau, the crustal structure that controls the temporal and spatial distribution of magmatic rocks, and the geological signature associated with mineral deposits.

ABSTRACT: Fluorite is one of the important mineral raw materials in the industry. In China, it is mainly distributed in the provinces and regions such as Hunan, Zhejiang, Jiangxi, Inner Mongolia, Fujian, and Henan provinces, boasting huge reserves and large numbers of deposits. However, most of the fluorite deposits are on a small or medium scale. The main fluorite deposits in China were studied in this paper. Their geological features and metallogenic regularity were summarized and compared. Meanwhile, based on their main genetic factors including metallogenic fluid sources and main metallogenic geological processes, they were divided into two groups, namely meso-epithermal deposits and magmatic-hydrothermal deposits. Furthermore, based on the prospecting achievements and research progress obtained in fluorite deposits in recent years, prospecting potential predictions were made for the metallogenic prospect areas and major prospecting areas of fluorite in China. This aims to provide a theoretical basis and direction for future fluorite prospecting in China.

With the advancement of the use of geophysical methods in mining exploration, the possibility of restudying known mineral deposits that could have greater potential than that previously estimated is opening up, as is the case in the Maricunga Belt (MB), which is a metallogenic belt located east of Copiapó, Chile, with a length of 200 km and oriented in the NNE-SSW direction. This belt hosts significant gold deposits classified as porphyry gold (-copper), epithermal gold (-silver) of a high sulphidation type, and transitional gold, in some districts. In this work we studied the characteristics of the MB through local earthquake tomography (LET), which revealed a clear spatial correlation between low Vp/Vs anomalies and the gold deposits, demonstrating that lithologic interpretation using Vp and Vs values of the seismic tomography makes sense for the most common rocks associated with the genesis of porphyry-type deposits. Furthermore, high Vp/Vs anomalies were correlated to the main regional faults around the study zone, which seem to have a robust structural control regarding the location of the deposits.

The Frontino-Morrogacho gold district is located on the western flank of the Western Cordillera, NW of Antioquia Province. Gold mineralizations in the area are spatially and genetically associated with the cooling of three mid- to late-Miocene age intrusive centers in the form of stocks and dikes (12-9 Ma): Cerro Frontino, La Horqueta and Morrogacho (El Cerro Igneous Complex). These composite magmatic pulses, with ultramafic to intermediate compositions, vary into diorite-, gabbro- and monzonitic-bearing phases. Mineralization in the complex is present as several structurally controlled fault veins, shear-related veins, sheeted quartz extension veins and quartz-carbonate tabular extension veins, with the development of swarms and nests of veins-veinlets, breccias and stockworks. Structures range from centimeter-wide individual veinlets to several meter-wide swarms of veins developed within broad mineralized structural corridors, with a metallic signature that consists of Au + Ag + Cu + Zn + Pb + As (± Te ± Bi ± Sb ± Hg ± W) assemblages. Veins are composed of multiple stages of mineralization, and the formation of these structures is enhanced by the presence of a local regime of extension and E-trending structures, including evidence of faults and shear zones with right-lateral displacement, which are likely involved in pluton emplacement and cooling. The ore mineralogy is composed of pyrrhotite, pyrite, chalcopyrite, sphalerite, galena and arsenopyrite assemblages formed in two or more mineralization stages, with complex Bi, Te, Sb and Hg mineral specimens associated with Au and Ag. Mineralized structures of the district present a preferential E-strike with dominant vertical to subvertical and occasional subhorizontal S-dips and secondary N- and NW-strikes that are steep to vertically E-dipping. The Frontino-Morrogacho Gold district presents characteristics related to the architecture, mineralogy and alteration of reduced (ilmenite-series) intrusion-related gold systems but is genetically associated with a parental oxidized magma source. The gold content is associated with three different families involving electrum, tellurides and alloys: gold rich (66 to 78% Au, 22 to 34% Ag), average (50 to 60% Au, 40 to 50% Ag) and silver rich (32 to 40% Au, 60 to 68% Ag). The formation of these bodies is associated with an N-S magmatic-metallogenic trend of Au-Ag-Cu deposits, which extend for more than 300 km along the Western Cordillera of Colombia. Similar plutonic suites span from the south of Chocó Province to the north of Antioquia Province, which indicates that the Frontino-Farallones-Botón arc can be proposed as an individual metallogenic belt.

Crustal architecture strongly influences the development and emplacement of mineral zones. In this study, we image the crustal structure beneath a metallogenic belt and its surroundings in the Bayankhongor area of central Mongolia. In this region, an ophiolite belt marks the location of an ancient suture zone, which is presently associated with a reactivated fault system. Nearby, metamorphic and volcanic belts host important mineralization zones and constitute a significant metallogenic belt that includes sources of copper and gold. However, the crustal structure of these features, and their relationships, are poorly studied. We analyze magnetotelluric data acquired across this region and generate three-dimensional electrical resistivity models of the crustal structure, which is found to be locally highly heterogeneous. Because the upper crust (< 25 km) is found to be generally highly resistive (> 1000 Ωm), low-resistivity (< 50 Ωm) features are conspicuous. Anomalous low-resistivity zones are congruent with the suture zone, and ophiolite belt, which is revealed to be a major crustal-scale feature. Furthermore, broadening low-resistivity zones located down-dip from the suture zone suggest that the narrow deformation zone observed at the surface transforms to a wide area in the deeper crust. Other low-resistivity anomalies are spatially associated with the surface expressions of known mineralization zones; thus, their links to deeper crustal structures are imaged. Considering the available evidence, we determine that, in both cases, the low resistivity can be explained by hydrothermal alteration along fossil fluid pathways. This illustrates the pivotal role that crustal fluids play in diverse geological processes, and highlights their inherent link in a unified system, which has implications for models of mineral genesis and emplacement. The results demonstrate that the crustal architecture—including the major crustal boundary—acts as a first‐order control on the location of the metallogenic belt. [ABSTRACT FROM AUTHOR]

The metallogenic belt is a geological unit for possessing potential of ore resources. The metallogenic system mainly focuses on the overall characteristics of mineralization from the aspects of metallogenic elements and processes, including deposit assembly, metallogenic series and their original link. The metallogenic system is an important evidence for dividing metallogenic belt and summarizing metallogenic regularity. East Tianshan orogenic belt, which is sandwiched between Tuha Basin and Tarim block, may be divided into four metallogenic belts in terms of spatial distribution, including Dananhu-Tousuquan Cu-Au-polymetallic metallogenic belt, Kanggurtag-Huangshan Au-Cu-Ni metallogenic belt, Aqishan-Yamansu Fe-Cu-polymetallic metallogenic belt and Caixiashan-Jiyuan Pb-Zn-Ag-polymetallic metallogenic belt. The temporal evolution of East Tianshan orogenic belt is distinctly characterized by multi-stage and multiple metallogenic system, including ① Middle-Late Proterozoic extension continental margin, where there occurs a metallogenic system of sedimentation Pb-Zn-Ag deposits; ② Ordovician-Carboniferous active continental margin, where there occurs a metallogenic system of VMS Cu-Zn deposits and porphyry Cu deposits; ③ Carboniferous island arc, where there occurs a metallogenic system of volcanic Fe-Cu deposits; ④ Late Carboniferous-Early Permian post-collision orogeny and superimposition of mantle plume, where there occurs a metallogenic system of magmatic Cu-Ni deposits and a metallogenic system of Au deposits related to ductile shear processes. [ABSTRACT FROM AUTHOR]

The article discusses research which analyzed the gravity and magnetic evidence for the geological setting of major mineral systems of the main metallogenic belts in South China. Topics covered include the metallogenic factors of the deposits, the difference in the type and metal association of the deposits, and the distribution of termination sites of different mineral systems in the area which provide indications for future ore-prospecting exploration in South China.

Abstract: The graphite minerals of Madagascar are mainly produced in the Archean-Paleoproterozoic sedimentary metamorphic strata. The whole island is divided into 3 graphite metallogenic belts, stretching from north to south, with the largest mineralized zone of 200 km long and 5000 m wide. The graphite orebodies appear in stratified, stratoid and banded shapes, spreading nearly in N-S with stable occurrence. The orebodies vary in size, with a maximum length of 6100 m, width of 327 m, and depth extension more than 1000 m. The grade of fixed carbon is 2.66%-9.02%. The graphite deposits in Madagascar are widely distributed, mostly super-large or medium-large scaled, with high grade and large grain size. Almost all of them are large crystalline graphites, which has vast resource potential. The resource amount of crystalline graphites is more than 200 Mt. [ABSTRACT FROM AUTHOR]

According to the geological structure evolution characteristics of the polymetallic metallogenic belt, the key to solve the problem of mineral resources shortage is to analyze the dominant deposit types, metallogenic mechanism, and metallogenic process of the polymetallic metallogenic belt. On this basis, the analysis method of geological structure evolution characteristics of polymetallic metallogenic belt is put forward. Taking the Wuyishan polymetallic metallogenic belt as the research object, the comprehensive investigation methods of 2D seismic exploration, drilling, geophysical logging, and sampling test are used to control the structural morphology and polymetallic in Wuyishan area. Through drilling, logging, and laboratory tests, the occurrence range, buried depth, thickness, and structure of the polymetallic metallogenic belt are controlled. According to the evaluation results of mineral resources potential in China, it is proposed that the main mineral exploration directions of Wuyishan polymetallic metallogenic belt are rare earth, fluorite, copper-molybdenum, lead-zinc, tin, gold, and silver. The main types of ore deposits include weathering crust-type (ion adsorption type) rare earth deposit, porphyry copper-molybdenum gold deposit, and sedimentary reformed lead-zinc polymetallic deposit. Hydrothermal fluorite deposit and hydrothermal w-sn-bi-mo-ta deposit related to acid rocks are delineated, and eight key prospecting areas in the metallogenic belt are delineated. [ABSTRACT FROM AUTHOR]

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Graphical abstract Highlights • Global Miocene last tectonic uplifts influenced sandstone-style uranium mineralization. • The tectonic uplift were 20–5 Ma while that of the uranium mineralization at 20–0.1 Ma. • The subtropical high pressure belts formed influenced the sandstone-style uranium deposits. Abstract The formation of sandstone-style uranium deposits are significantly controlled by the latest tectonic uplift events, especially those generated in an open system by the infiltration of meteoritic water. This study explores the spatiotemporal relationship between global Miocene tectonics and sandstone-style uranium deposits to evaluate the link between tectonic uplift and metallogenic ages. In general, modern landforms were shaped by diverse global tectonic events that began in the Middle and Late Miocene. This includes the formation of continental-scale faults and fold belts, including the uplift of the three broadly contemporaneous ranges, the Alpine–Himalayan Belt, the Cordillera, and the East African Rift. These events were accompanied by intense magmatic activity, as well as an increase in the spreading rates of oceanic ridges and higher sedimentation rates in the Pacific, Indian, and Atlantic oceans. Modern global climate patterns are a direct consequence of these Miocene tectonic events. Studies on sandstone-style uranium deposits report that though their stratigraphic ages extend from the Proterozoic to the Cenozoic, they notably occur from the Late Mesozoic to the Neogene. Uranium mineralization ages are concentrated between 20 and 0.1 Ma, clustering mainly in the Miocene although remobilizations are known to have occurred subsequently, some even in the Holocene. Global tectonics in the Miocene, between 20 and 5 Ma, resulting in the regional uplift of mountain ranges and continental tilts, may have exerted significant control over the migration directions of uranium-bearing fluids that formed these sandstone-style uranium deposits. Climate patterns in the Miocene, specifically subtropical high-pressure belts on both sides of the equator controlled the creation of arid and semi-arid areas, creating characteristic rainfall patterns which would also have influenced the spatial distribution of these uranium deposits. Thus, the spatiotemporal characteristics of most sandstone-style uranium deposits in the world were controlled by global tectonics in the Miocene that uplifted mountain ranges and tilted continents, generating subtropical high-pressure belts and the Asian high pressure region. In addition to new ideas adding greater research value to the study of global sandstone-style uranium mineralization, this paper also provides a new exploration indicator for sandstone-style uranium deposits. [ABSTRACT FROM AUTHOR]

Abstract The eastern Tianshan belt, an important part of the Central Asia metallogenic province, has attracted a large amount of attention in terms of its geological structures and mineralization processes. This study intends to analyze the geological structures and metallogenic characteristics of the eastern Tianshan, for determining the distribution pattern of polymetallic deposits and guiding for polymetallic minerals exploration by analysis of gravity and aeromagnetic and seismic data. Long wavelength gravity and magnetic anomalies reflect differences among the basement structure in this area, and the residual gravity and magnetic anomaly highs reflect the uplift of the upper Paleozoic and high-density volcanic rocks. The results of various edge recognition techniques provide detailed structural information: the major fault structures are nearly EW, NEE, and NW-trending and the massive rocks and ore deposits extend east-west in the study area. Regional mineralization is closely related to the tectonic-magmatic activity and to the deep faults in basement. The eastern Tianshan can be divided into three different series of polymetallic metallogenic belts by the Kangguertag-Huangshan and Aqikekuduk fault zones. We may indicate the most favorable areas for prospecting polymetallic deposits, which are located near the places such as the EW-NEE trending structure zones or at the intersection of several sets of structures. Our synthesis and interpretations may provide important reference for further research on regional dynamics and mineralization in the eastern Tianshan. Highlights • Detailed geophysical fields data were processed, analyzed and interpreted. • The large-scale structure systems were established. • The relationships among geophysical fields, geological structures and the endogenetic deposits were analyzed [ABSTRACT FROM AUTHOR]

The gold deposits in Qinghai can be divided into fractured alteration rock-type, marine volcanic rock-type, skarn-type, overlay-type and sand-type. The forming ages of deposit are continuous, ranging from Early Paleozoic to Cenozoic. The peaks of deposit development appear at Late Paleozoic and Mesozoic. Late Paleozoic deposits are mainly located in the northern margin of Qaidam Basin, and Mesozoic deposits mainly distribute in East Kunlun, West Qinling and North Bayankala. The rock gold deposits mainly distribute to the north of 35°N. The fractured alteration rock-type gold deposits are the main in Qinghai, and are strictly controlled by structures. The output and distribution of gold orefields and deposits are controlled by regional deep fractures and secondary structural units as well. Based on the information of gold orefields, deposits and metallogenic characteristics, there are 19 gold ore-concentrated areas divided. According to the ore-concentrated areas, mineralization information and regional metallogenic conditions, the 10 gold metallogenic prospects were proposed. Considering several factors such as regional geological background, information integration and research level, the 5 gold metallogenic prospects including Suganhu-Xitieshan, Saishikenan-Chachalongwa, Qimantage, Citieshan-Zhiyu and Tongde-Tongren are most promising. The above 5 gold metallogenic prospects mainly distribute in the northern and central Qinghai, and are related to the northern margin of Qaidam mineralization belt (Ⅲ-6), the East Kunlun metallogenic belt (Ⅲ-8) and the West Qinling metallogenic belt (Ⅲ-9). [ABSTRACT FROM AUTHOR]

The geotectonic evolution of Longshoushan metallogenic belt experiences three tectonic periods, including the initial stage and development of Proterozoic Longshoushan margin subsiding belt, and the active uplift of Paleozoic subsiding belt and partial collapse of continental margin belt, and the activity of Meso-Cenozoic fault block. Longshoushan metallogenic belt locates at the southwest margin of North China paleoland, and the paleoland and its margin are the most important uranium metallogenic zones. Uranium mineralization is controlled by geotectonic evolution; accordingly uranium-mineralized process is divided into three metallogenic periods, including Proterozoic, Paleozoic and Meso-Cenozoic. Corresponding with the three metallogenic periods, Longshoushan metallogenic belt form three metallogenic series of uranium mineralization, which are separately related to Lower Proterozoic metamorphic rocks, the crustal remelting granites in Qilian stage and the fault block uplift and sag in Meso-Cenozoic. The metallogenic model of Longshoushan metallogenic belt can be summarized as the pre-enrichment of Lower Proterozoic stratum, the pre-enrichment of (Luliang stage) pegmatoid alaskite (or the pre-enrichment of granitoids in Qilian stage), the pre-enrichment of (Tianshan stage) fault structure and hydrothermal alteration, and the industrial enrichment of (Indosinian, Sichuan stage and Himalayan) vein material superimposed. [ABSTRACT FROM AUTHOR]

The Patricia ore deposit represents an unusual example of economic Zn–Pb–Ag mineralization at the northernmost end of the Late Eocene–Oligocene metallogenic belt in Chile. It is hosted by volcano-sedimentary units, which are typically tuffaceous and andesitic breccias. The ore body consists of a set of subvertical E-W vein systems developed under a sinistral strike-slip regime that included transtensive domains with generalized extensional structures where the ores were deposited. The deposit is divided into two blocks by a set of NNW-ESE-trending reverse faults, which uplifted the eastern block and exhumed thicker and deeper parts of the deposit. At least 200 m of volcano-sedimentary pile hosting the mineralization has been eroded in this block. By contrast, the western block exposes a shallower part of the system where cherts, amorphous silica and jasperoids occur. Three main stages of mineralization have been defined: (1) pre-ore stage is characterized by early quartz, pyrite and arsenopyrite, (2) base-metal and silver stage; characterized by sphalerite (6 to 15 mol% FeS), galena, chalcopyrite, pyrrhotite and Ag-bearing minerals (freibergite, polybasite, stephanite, pyrargyrite, freieslebenite and acanthite) and (3) post-ore stage; characterized by late quartz, kutnohorite and minor sulfides (arsenopyrite, sphalerite, pyrite, galena, Ag-bearing minerals and Pb-sulfosalts). Whole-ore geochemistry shows two groups of elements that are positively correlated; 1) Ag–Cd–Cu–Pb–Zn related to the base metal sulfides and 2) Au–As–Ge–Sb–W related to arsenopyrite and pyrite. Hydrothermal alteration is pervasive in the outcropping mineralized areas, including silicification and locally, vuggy silica textures. At depth, chloritic and sericitic alteration is developed along vein selvages and is superimposed to the regional propylitic alteration. Fluid inclusions indicate that the base-metal ores were deposited from 250 to 150 °C moderate salinity fluids (1–9 wt.% NaCl). The pre-ore stage is characterized by a saline fluid (6–22 wt.% NaCl) and between 210 and 250 °C whereas the post-ore stage has salinity of 4–8 wt.% and temperature from 175 to 215 °C. Cooling was the mechanism of ore mineral precipitation in the Patricia deposit, although mixing of fluids could have occurred in the pre-ore stage. Mineralogical, geochemical and fluid inclusion evidence is consistent with an intermediate sulfidation (IS) epithermal deposit type. This study highlights the high potential for hidden economic mineralization at depth in the western block and for extension of the ore body both to the south and to deeper levels in the eastern block of the Patricia ore deposit. To a larger extent, the implications of finding such polymetallic epithermal style of mineralization in the northern Chile Precordillera is relevant both to the regional metallogenic perspective and to the exploration potential of the region, where the late Eocene–early Oligocene metallogenic belt apparently disappears. [ABSTRACT FROM AUTHOR]

A 300 km long seismic reflection profile was acquired across the Middle and Lower Reaches of the Yangtze River (MLY) metallogenic belt and its adjacent areas. The objective of the survey was to establish the deep architecture and geodynamic framework of the region. Results based on the interpretation of the deep seismic data include (1) Tan-Lu fault appears as a subvertical thrust fault or transpression fault with its deep portion dipping toward the southeast; (2) the Zhangbaling uplift is squeezed out along this fault; (3) complex upper crustal deformation structures beneath the Chuquan depression include both kink bands, thrusts, imbrication and fold structures reflecting contraction deformation, and detachment fault and normal-fault structures reflecting extensional deformation; (4) the “crocodile” reflection structure emerging beneath the Tan-Lu fault and Ningwu–Lishui volcanic basin, which represents the decoupled deformation process of the upper and lower crust associated with intra-continental subduction; (5) further to the southeast, the upper crust deformation shows a large-scale “wave-form” pattern, making crustal scale syncline and anticline; (6) the entire section of the reflection Moho is clearly discernible at depth of 30.0–34.5 km, and the Moho beneath the Middle and Lower Reaches of Yangtze River metallogenic belt is shallowest, while the Moho beneath the North China block is deeper than that beneath the Yangtze block. The Moho offsets could be seen beneath the Ningwu volcanic basin. The seismic reflection data suggest that lithosphere delamination and asthenosphere upwelling that may result from the Mesozoic intra-continental orogenesis is responsible for the formation of large scale magmatism and mineralization in the MLY metallogenic belt. [ABSTRACT FROM AUTHOR]

SE China is well known for its Mesozoic large-scale granitoid plutons and ore deposits. In SE China, igneous rocks with intrusion ages between 180 and 125 Ma generally become progressively younger towards the NE. More specifically, 180-160 Ma igneous rocks are distributed throughout a broad area, with mineralization ranging from Cu-Au and Pb-Zn-Ag to W-Sn; 160-150 Ma plutons are present mainly in the Nanling region and are associated with the large-scale W-Sn mineralization; younger igneous rocks occur in the NE area that has many fewer deposits. These can be plausibly interpreted as reflecting a southwestward subduction followed by a northeastward rollback of a subducted oceanic slab, in rough agreement with contemporaneous drift of the Pacific plate. Consistent with this scenario, SE China contains three Jurassic metallogenic belts distributed systematically from NE to SW: (1) a Cu-(Au) metallogenic belt in the NE corner of the South China Block, represented by the Dexing porphyry Cu deposits; (2) a Pb-Zn-Ag metallogenic belt in the middle, represented by the Lengshuikeng Ag and Shuikoushan Pb-Zn deposits; and (3) the famous Nanling W-Sn metallogenic belt in the SW. The distribution of these metallogenic belts is analogous to those in South America where Fe deposits are distributed close to the subduction zone, followed by porphyry Cu-Au deposits and Pb-Zn-Ag deposits in a medial zone, and Sn-W deposits distant from the trench. Inasmuch as quite a few late Mesozoic Fe deposits occur in the Lower Yangtze River Belt to the NE of the Cu-Au deposits in SE China, the distribution of late Mesozoic deposit belts in SE China is identical to that in South America. Therefore, southwestward subduction of the Pacific plate and the corresponding slab rollback are proposed here to explain the distributions of the late Mesozoic (180-125 Ma) magmatism and the associated metallogenic belts in SE China. [ABSTRACT FROM AUTHOR]

Recent mineral exploration in the Gangdise porphyry copper deposit belt, an important component of the Himalaya-Tethyan metallogenic belt, has led to the discovery of a number of deposits, as exemplified by the world-class Miocene Qulong porphyry Cu deposit. This paper reviews major advances in the studies of ore genesis and metallogenic regularity and progresses in mineral exploration of porphyry Cu deposits in the belt. Existing problems and suggestion for future exploration also are given. [ABSTRACT FROM AUTHOR]

[Display omitted] • A teleseismic full waveform inversion method is used to study the crustal velocity. • A low velocity zone corresponds to the faulting, seismic zone, and ore deposits very well. • The seismic pumping might cause the upwelling of thermal flow. It is crucial to image the crustal velocity structure with higher resolution to understand the relationship between crustal seismicity and metallogenic mechanisms, which remain challenging targets for conventional seismic tomography. Teleseismic tomography via body-waves can image velocity well in the upper mantle, but poorly in the crust. In this study, we have developed a teleseismic full waveform inversion (TFWI) method based on the frequency-wavenumber spectral element method (FK-SEM) hybrid to improve the resolution of teleseismic P-waves in the crust. We used the TFWI method to study the crustal velocity by using two large teleseismic events recorded by 29 portable stations with ~5 km intervals across the Zhenghe-Dapu Fault (ZDF) in the Cathaysia Block. This is the first attempt using the FK-SEM hybrid on real data. As expected, we obtained a 2D velocity model in the crust that had high lateral resolution. There is an obvious low velocity zone (LVZ) in the crust below east side of the ZDF, while a relatively high velocity anomaly exits within its west side. Combined with previous geochemical and geological results, this LVZ is explained as remnant magma due to the large-scale magmatism in the Late Jurassic and Early Cretaceous. According to the spatial correlation among the LVZ, local earthquakes, faulting, and major ore deposits, we consider that seismic pumping might be a mechanism of thermal fluid transport for the mineralization. [ABSTRACT FROM AUTHOR]