Ore Geology Reviews最新文献

{"title":"Genesis of the Ulaan silver-lead–zinc deposit in Northeast Mongolia: Constraints from S and Pb isotopes, together with U-Pb and Rb-Sr geochronology","authors":"Taotao Wu ,&nbsp;Chunji Xue ,&nbsp;Yongheng Zhou ,&nbsp;Lu Chai ,&nbsp;Qingshuang Wang ,&nbsp;Qingzhong Bao","doi":"10.1016/j.oregeorev.2024.106262","DOIUrl":"10.1016/j.oregeorev.2024.106262","url":null,"abstract":"<div><div>The Ulaan silver-lead–zinc deposit (hereinafter referred to as the Ulaan deposit) is identified as the largest silver-lead–zinc polymetallic deposit in Mongolia, with proved reserves including 2,240 tons of silver (Ag; average grade: 49 g/t), 440,000 tons of lead (Pb; average grade: 1.13 %), and 810,000 tons of zinc (Zn; average grade: 2.07 %). However, the genesis of this deposit remains unclear. The Ag-Pb-Zn ore bodies in the deposit, occurring as cylinders in shape within the Middle-Late Jurassic rhyolites, are governed by a concealed breccia pipe. The ore minerals include galena, sphalerite, and pyrite, followed by chalcopyrite, hematite, stibnite, and siderite. The primary alterations of the surrounding rocks include silicification, chloritization, kaolinization, argillization, carbonatization, and skarnization. The Rb-Sr dating of sulfide minerals and associated vein minerals in the ores yielded isochron ages varying in a range of 146 ± 3 Ma (<em>n</em> = 6, MSWD=1.3), suggesting mineralization during the Late Jurassic. The δ³⁴S values of sulfide minerals in the ores range from 1.6 ‰ to 4.3 ‰, suggesting that the sulfur originated primarily from magmas or deep sources. The isotopic compositions of coexisting sphalerite-galena minerals in the deposit revealed mineralization temperature estimates ranging between 331 °C and 449 °C, indicating a medium- to high-temperature ore-forming conditions. The sulfide minerals exhibit ²⁰⁸Pb/²⁰⁴Pb ratios ranging from 38.138 to 38.301, ²⁰⁷Pb/²⁰⁴Pb ratios from 15.543 to 15.594, and ²⁰⁶Pb/²⁰⁴Pb ratios from 18.318 to 18.354, suggesting that ore-forming metals, represented by Pb, also originated primarily from mantle source. The zircon U-Pb dating of rhyolites in the ore-hosting strata and ore-controlling breccia pipes yielded ages of 160.6 ± 1.7 Ma (<em>n</em> = 24, MSWD=0.68) and 161.6 ± 1.6 Ma (<em>n</em> = 30, MSWD=0.89), respectively, indicating volcanic eruptions during the early Late Jurassic. These ore-hosting rhyolites exhibit characteristics of A-type rhyolites, suggesting that they were formed in an intracontinental extensional environment. These rhyolites share similar rare earth element (REE) distribution patterns with fluorite formed in the main mineralization stage, suggesting a genetic link between the mineralization and magmatic processes. This study proposes that the Ulaan deposit was a hydrothermal deposit formed in an extensional environment following the closure of the Mongol-Okhotsk Ocean, with ore-forming metals and hydrothermal fluids associated with volcanic rocks or magmatic-hydrothermal processes.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106262"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of antimony mineralization in the Yangla polymetallic deposit, northwestern Yunnan, SW China: Insights from calcite Sm-Nd dating and C-O-Sr isotopes","authors":"Xinfu Wang ,&nbsp;Bo Li ,&nbsp;Shucheng Tan ,&nbsp;Guo Tang ,&nbsp;Zuopeng Xiang ,&nbsp;Yuedong Liu","doi":"10.1016/j.oregeorev.2024.106266","DOIUrl":"10.1016/j.oregeorev.2024.106266","url":null,"abstract":"<div><div>Calcite is the main gangue mineral in antimony (Sb) deposits, and its compositions can reflect the physicochemical conditions of Sb mineralization. The Yangla is the largest Sb deposit (10 kt Sb @ 14.87 %) in the Jinshajiang suture zone (SW China), and the lode-type Sb orebodies are stratabound or developed along NE-trending fracture zones in marble. To constrain the time of Sb mineralization and establish any genetic link with the local magmatism and wallrocks, we performed calcite Sm-Nd dating and bulk C-O and in-situ Sr isotope analyses. The results show that the Sb mineralization (∼155 Ma) was considerably younger than the Cu-Pb-Zn mineralization (∼230 Ma), skarn alteration (∼234 Ma), and granitoid emplacement (∼230 Ma) at Yangla, but much older than the local W mineralization (∼30 Ma). The initial ⁸⁷Sr/⁸⁶Sr ratio of calcite (0.71972–0.72208) is much higher than that of the Triassic granodiorite (0.71149– 0.71990) and Carboniferous basalt (0.70562–0.70995), suggesting mixed source of calcite from the ore fluids and Devonian wallrocks. The ore-related calcite has δ¹³C_PDB (−4.53 to − 2.33 ‰) and δ¹⁸O_SMOW (+14.98 to + 16.30 ‰) values that fall between the granite and marine carbonate isotopic fields. This suggests that the ore-forming fluid may be related to the low-temperature alteration of granites and marine carbonate dissolution. Simulated precipitation temperature calculation for the ore-related calcite yielded 200–150 °C, and the calcite C-O isotopes suggest that fluid mixing, fluid-rock interactions, and CO₂ degassing may have precipitated the stibnite in the fracture zones under low-temperature conditions. Our new geochemical results and published data suggest that the Yangla polymetallic mineralization was multiphase, comprising the Indosinian Cu-Pb-Zn (∼230 Ma), Yanshanian Sb (∼155 Ma), and Himalayan W-Sb (∼30 Ma) metallogenic events.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106266"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochronology, in-situ elements and sulfur isotopes of sulfides from the Songjiashan cobalt-iron deposit in the Zhongtiao mountains of North China Craton: Implications for cobalt occurrence and ore genesis","authors":"Wen Li ,&nbsp;Bingyu Gao ,&nbsp;Caiyun Lan ,&nbsp;Brendan A. Bishop ,&nbsp;Wenjun Li ,&nbsp;Xin Zhang ,&nbsp;Changle Wang ,&nbsp;Lingang Xu ,&nbsp;Lianchang Zhang","doi":"10.1016/j.oregeorev.2024.106265","DOIUrl":"10.1016/j.oregeorev.2024.106265","url":null,"abstract":"<div><div>The Songjiashan Co-Fe deposit in the central part of the “Tongshan skylight” on the southeastern edge of the Zhongtiao Mountains is hosted by the volcanic-sedimentary rock series of the Paleoproterozoic Songjiashan Group. The spatial distribution of the orebodies is controlled by south-north trending rock units. Based on microscopic observations, the dominant ore minerals included magnetite, pyrite, chalcopyrite, carrollite, and linnaeite, while gangue minerals comprised quartz, calcite, sericite, and chlorite. Cobalt-iron ores had massive, banded, disseminated, and veinlet texture, and alteration of the host rocks included silicification, sericitization, pyritization, carbonation, and chloritization. Mineralization processes of the Songjiashan deposit were grouped into three periods: sedimentation, metamorphism, and hydrothermal. The Co concentrations in hydrothermal pyrite (Py-III) varied from 1.05 % to 3.75 %, with an average of 2.45 %. Cobalt in pyrite was homogeneously distributed and inversely correlated to Fe, indicating that Co isomorphically replaced Fe in pyrite. The characteristic Co/Ni ratio of pyrite varied greatly, ranging from 0.1 to 1000, reflecting various genetic types of sedimentation, metamorphism, and hydrothermal mineralization, with the main mineralization period primarily related to hydrothermal activities. Zircon U-Pb geochronology of the host rock and Re-Os isochron of Co-bearing pyrites indicate that Co mineralization mainly occurred at ∼2100 Ma. <em>In-situ</em> S isotopic analysis of sulfides reveals two peak δ³⁴S values of 5–9 ‰ and 12–16 ‰. We interpret that the former value reflects the mixing of volcanic and marine sulfate sources, while the latter value is mainly artributted to marine sulfate sources. All δ³⁴S values were lower than those of Proterozoic marine sulfates (15–20 ‰). Accordingly, we infer that thermochemical sulfate reduction plays a key role in marine sulfate reduction, and that the formation of Co-rich ore bodies in the Songjiashan deposit have undergone processes of initial sedimentation, metamorphism-deformation, and subsequent hydrothermal overprinting. Genetically, we suggest that the Songjiashan deposit belongs to a sedimentary-metamorphic hydrothermal superposition type Co-Fe deposit.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106265"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genesis of the Longfengchang polymetallic sulfide deposit in the southwest Fujian depression, southeast China, with a comparative study of the “Makeng-Type” iron deposit","authors":"Qiang Wang ,&nbsp;Hongxin Fan ,&nbsp;Xiangdie Cui ,&nbsp;Yulong Yang ,&nbsp;Siyue Yao ,&nbsp;Fengchun Li ,&nbsp;Huimin Zhang","doi":"10.1016/j.oregeorev.2024.106271","DOIUrl":"10.1016/j.oregeorev.2024.106271","url":null,"abstract":"<div><div>The Southwest Fujian Depression Belt is a prominent metallogenic zone for skarn-type iron polymetallic deposits in China, with the Longfengchang (LFC) sulfur polymetallic deposit representing a medium-scale, sulfide-dominated deposit in this region. This study conducted a detailed analysis of the LFC deposit, focusing on its mineralogy, mineral composition, and in-situ sulfur isotopes, alongside a comparative study with the “Makeng-type” deposit. The study aims to elucidate the genesis of the LFC deposit, its relationship with the “Makeng-type” deposit, and the factors underlying differences in dominant economic minerals and resource scale. The LFC deposit is hosted within the skarn above the fault contact zone between the Lindi Formation sandstone and the Chuanshan–Qixia Formation carbonate, with mineralization stages classified as skarn-magnetite, quartz-sulfide, and carbonate. LFC garnets are primarily composed of CaO, TFeO, and SiO₂, with minor Al₂O₃ and trace amounts of MgO and MnO, classifying them as distal exoskarn andradite. The presence of Mn³⁺ substituting for Fe³⁺ in garnet suggests that the ore-forming fluid during the garnet skarn stage was likely oxidizing and weakly acidic. LFC pyrites exhibit Co/Ni ratios primarily ranging from 1 to 10, decreasing from Py₁ to Py₃. In-situ sulfur isotope δ³⁴S values range from −1.48 to 3.51 ‰, centering around 0 ‰, and increase from Py₁ to Py₃, suggesting a magmatic-hydrothermal origin and a cooling metallogenic process. Thus, the LFC deposit is classified as a magmatic-hydrothermal skarn-type deposit, consistent with the genesis of “Makeng-type” deposits. The absence of the Jinshe Formation, and mantle-derived magma contribution, and less developed “Si-Ca” interface may explain the smaller scale and different mineralization type in the LFC deposit compared to the “Makeng-type” deposit. The key prospecting area for large iron-sulfur polymetallic deposits in the Southwest Fujian Depression Belt should feature a nappe structural window, well-preserved Jinshe Formation, developed “Si-Ca” interface, Yanshanian high-K calc-alkaline to shoshonitic intrusions, and coeval mantle-derived magma.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106271"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Application of (U-Th)/He hematite geochronology to the Çaldağ lateritic Ni-Co deposit, Western Anatolia: Implications for multi-stage weathering events during interglacial periods/segments” [Ore Geology Reviews 172 (2024) 106203]","authors":"Nilay Gülyüz ,&nbsp;İlkay Kuşcu ,&nbsp;Martin Danišík","doi":"10.1016/j.oregeorev.2024.106223","DOIUrl":"10.1016/j.oregeorev.2024.106223","url":null,"abstract":"","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106223"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The occurrence of cobaltite nanoparticles in pyrite from the De’erni deposit, NW China","authors":"Lei Yan ,&nbsp;Xianzheng Guo ,&nbsp;Yu Fan ,&nbsp;Jun Huang ,&nbsp;Tong Zuo ,&nbsp;Taofa Zhou","doi":"10.1016/j.oregeorev.2024.106268","DOIUrl":"10.1016/j.oregeorev.2024.106268","url":null,"abstract":"<div><div>Cobalt (Co) is a critical metal that occurs in many types of deposits, Co minerals and sulfide hosts are the main forms of Co occurrence. Pyrite is the most important cobalt-bearing mineral in the De’erni Cu-Zn-Co ultramafic-hosted volcanogenic massive sulfide deposits. However, the occurrence and enrichment of Co in pyrite remain unclear. In this study, a combination of LA-ICP-MS and STEM techniques was employed to conduct a detailed mineralogical investigation of pyrite in the De’erni deposit. The results revealed significant variations in cobalt content among pyrite samples from different mineral assemblages. Pyrite associated with magnetite (Mag), pyrrhotite (Po), chalcopyrite (Ccp), arsenopyrite (Apy), and bornite (Bn) (Py-Mag-Po-Ccp-Apy-Bn suite of mineral assemblages) exhibited the highest cobalt content, which ranged from 672.6 ppm to 2007 ppm. Cobalt occurs in two forms in the pyrite from the De’erni deposit: as cobaltite nanoparticles (NPs) and as a substitute for iron (Fe) in the pyrite lattice. The enrichment mechanism of cobalt in pyrite was explored at the deposit and mineral scales. The results indicate that a decrease in ore-forming fluid temperature and an increase in cobalt content may be significant factors contributing to cobalt enrichment at the deposit scale. Lattice defects may play a crucial role in cobalt enrichment within the pyrite lattice. Furthermore, the discovery of cobaltite NPs in pyrite could provide new insights for explaining the complex zonation of the cobalt element in pyrite.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106268"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tourmaline geochemical and B isotopic constraints on pegmatite Li mineralization and exploration","authors":"Yang Sun ,&nbsp;Bin Chen ,&nbsp;Wen-Jing Li ,&nbsp;Shuai-Jie Liu","doi":"10.1016/j.oregeorev.2024.106257","DOIUrl":"10.1016/j.oregeorev.2024.106257","url":null,"abstract":"<div><div>Pegmatite–related deposits represent one of the most significant types of mineral deposits housing rare–metal elements such as Li, Be, Nb, Ta, Rb, Cs, and Sn. Although extensively studied for almost two centuries, the mechanism controlling the rare–metal mineralization in pegmatites remains controversial. In addition to the enrichment of rare–metal elements in the source region, differentiation processes (e.g., fractional crystallization and liquid immiscibility) after emplacement may have also contributed to the concentration and mineralization of rare–metal elements. However, compared to fractional crystallization, the role of liquid immiscibility in pegmatite mineralization has received limited attention. In this study, the element and boron (B) isotopic compositions of tourmalines from different textural zones (Zones I–VI) of the rare–metal–mineralized Koktokay No. 3 pegmatite, Altai, NW China, as well as from the altered country rock and the border zone, were analyzed to evaluate the role of liquid immiscibility in the generation of Li–mineralized pegmatites. Tourmalines display a variety of compositions, ranging from schorl and elbaite in the outer zones to elbaite in the inner zones of the Koktokay No. 3 pegmatite. Tourmalines from Zones I–III exhibit no obvious internal textures, whereas some tourmalines from Zones IV–VI have replacement textures or abrupt zonations. The distinction is attributed to the absence and presence of exsolving fluids during their formation, respectively. Tourmalines in Zones I–III and VII–VIII display less variable δ¹¹B values (–15.07 ‰ to –12.21 ‰ and –14.16 ‰ to –13.10 ‰, respectively), reflecting a negligible B isotope fractionation produced by fractional crystallization during the pegmatite evolution. By contrast, tourmalines in Zones IV–VII exhibit more significant variations in δ¹¹B values (–14.83 ‰ to –8.09 ‰) compared to those in Zones I–III and VII–VIII. The high δ¹¹B tourmalines in Zones IV–VII were most likely crystallized from the fluids exsolving from the highly evolved pegmatite–forming magma. Their occurrence indicates the fluid exsolution occurring between zones IV and V, where Li mineralization began in the Koktokay No. 3 pegmatite. The mineralization of rare–metal elements is closely linked to the evolution of magma into a coexisting magma–fluid system. In addition, Li–mineralized pegmatites are characterized by tourmalines with Fe³⁺Al_-1 substitution and higher Zn, Li, Li/Sr, and V/Sc than barren pegmatites. These differences are believed to be due to the higher <em>f</em>O₂ and greater extent of magmatic differentiation in Li–mineralized pegmatites compared to the barren ones. These findings provide new insights into using the geochemical compositions of tourmalines as a guide for exploring Li–mineralized pegmatites.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106257"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-supervised graph convolutional networks for integrating continuous and binary evidential layers for mineral exploration targeting","authors":"Yongliang Chen ,&nbsp;Bowen Chen ,&nbsp;Alina Shaylan","doi":"10.1016/j.oregeorev.2024.106260","DOIUrl":"10.1016/j.oregeorev.2024.106260","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Effectively integrating evidential layers of different data types from multi-disciplinary geosciences to predict mineral prospecting targets is the crucial step for mineral exploration. Because the commonly used evidential layer integration method, such as statistical methods and machine learning methods, can only deal with the evidential layers of the same data type, divergent data types must be transformed into the same data type that the evidential layer integrating method can handle. However, the data type transformation inevitably results in the loss of some information in the original data type. To solve this problem, a semi-supervised graph convolutional networks (SSGCN) for graph-structured data classification in machine learning field was adopted to integrate binary and continuous evidential layers to predict mineral prospecting targets. A case study of mineral exploration targeting was carried out in the Lalingzaohuo area, Qinghai Province, China. The mineral exploration data collected during the 1:50,000 geological survey was used to train a SSGCN classification model to predict polymetallic prospecting targets. The input graph-structured data of the SSGCN model is composed of an adjacency matrix and a feature matrix. To test whether a high-performance SSGCN classification model can be established for integrating continuous and binary evidential layers in mineral exploration targeting, in this study, the adjacency and feature matrices were constructed using (&lt;em&gt;a&lt;/em&gt;) continuous geochemical evidential layers, (&lt;em&gt;b&lt;/em&gt;) binary geological and geophysical evidential layers, (&lt;em&gt;c&lt;/em&gt;) binary geological, geophysical and geochemical evidential layers, (&lt;em&gt;d&lt;/em&gt;) continuous geochemical evidential layers and binary geological and geophysical evidential layers, (&lt;em&gt;e&lt;/em&gt;) continuous geochemical evidential layers and binary geological, geophysical and geochemical evidential layers, and (&lt;em&gt;f&lt;/em&gt;) binary geological, geophysical, geochemical evidential layers and continuous geochemical evidential layers. Accordingly, the six SSGCN models were built and used to predict polymetallic prospecting targets. In terms of the receiver operating characteristic (ROC) curves, the performances of the six SSGCN models from high to low are, respectively, models (&lt;em&gt;e&lt;/em&gt;) (&lt;em&gt;c&lt;/em&gt;), (&lt;em&gt;d&lt;/em&gt;), (&lt;em&gt;a&lt;/em&gt;), (&lt;em&gt;f&lt;/em&gt;) and (&lt;em&gt;b&lt;/em&gt;). The area under the ROC curves of the six SSGCN models from high to low are, respectively, (&lt;em&gt;e&lt;/em&gt;) 0.9489, (&lt;em&gt;c&lt;/em&gt;) 0.9457, (&lt;em&gt;d&lt;/em&gt;) 9080, (&lt;em&gt;a&lt;/em&gt;) 0.9039, (&lt;em&gt;f&lt;/em&gt;) 0.8717 and (&lt;em&gt;b&lt;/em&gt;) 0.8453. The polymetallic prospecting targets predicted by the six SSGCN models occupy, respectively, 22.43 %, 8.12 %, 12.93 %, 7.99 %, 7.60 %, 24.16 % of the study area; and correctly classified known polymetallic deposits are, respectively, 88 %, 71 %, 88 %, 82 %, 88 % and 88 %. These results show that the SSGCN model performs best in predicting polymetallic prospecting targets when the cont","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106260"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluorescent sphalerite rich in tungsten, copper, gallium, silver, and other elements from the Cordilleran-style, polymetallic veins of Philipsburg, Montana","authors":"Celine M.E. Beaucamp ,&nbsp;Christopher H. Gammons ,&nbsp;Jay M. Thompson ,&nbsp;Heather A. Lowers","doi":"10.1016/j.oregeorev.2024.106267","DOIUrl":"10.1016/j.oregeorev.2024.106267","url":null,"abstract":"<div><div>Sphalerite from the central, high-sulfidation zone (enargite-stable) of the Philipsburg polymetallic mining district, southwest Montana, displays unusually bright fluorescence (red, orange, yellow, blue, purple, green) under longwave UV light (365 nm). LA-ICP-MS analysis reveals the fluorescent sphalerite has very low Fe (average &lt; 100 ppm) and variable content of other trace elements that correlate to luminescence color banding. Mean/maximum content (in ppm) in fluorescent sphalerite for selected elements are 5.7/7900 Ag, 107/11800 As, 1400/4730 Cd, 917/30400 Cu, 381/5000 Ga, 32/696 Ge, 119/2130 In, 230/8190 Mn, 43/3000 Pb, 16/1700 Sb, and 89/1980 W. This study is the first to document elevated tungsten content (&gt;10 ppm) in sphalerite. Copper is closely correlated with Ga, consistent with the coupled substitution: Cu⁺ + Ga³⁺ = 2Zn²⁺. Similar coupled substitution reactions can be written for Ag⁺, In³⁺, As³⁺, Sb³⁺, Bi³⁺, and Ge⁴⁺. However, the brightest red fluorescent bands are most closely related to the unexpected presence of W. Sphalerite with high Cu and Ga but lacking W fluoresces yellow and shows a single Raman peak at 349 cm⁻¹ corresponding to pure sphalerite. In contrast, red-fluorescent sphalerite shows the presence of a second peak at 427 cm⁻¹ that increases in intensity with increased W content. We propose that tungsten enters the sphalerite lattice as W⁶⁺ via a substitution such as W⁶⁺ + 4Cu⁺ = 5Zn²⁺ and that this substitution creates lattice strain that results in the anomalous fluorescence and Raman signals. Sphalerite bands with low concentrations of Cu and Ga fluoresce blue or green. Vivid blue fluorescence is displayed by sphalerite with high Cd (&gt;1000 ppm) but low concentrations of all other trace elements. Sphalerite from the low-sulfidation peripheral mines of the Philipsburg district contains high Fe (&gt;10,000 ppm) and does not fluoresce. Nonetheless, this sphalerite is also highly enriched in trace metals, including Ag (mean 2480/max 8660 ppm), Cu (1610/3440), Mn (7020/8100), and Sb (1960/6390). The results of this study underscore the importance of including tungsten in the list of analytes in future studies of trace elements in sphalerite. In addition, a hand-held UV lamp may be a rapid and cost-effective method to screen sphalerite of variable composition in outcrop or drill core. It may be a useful exploration tool to vector towards a high-sulfidation zone of a zoned porphyry or epithermal deposit, when it is present.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106267"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age and petrogenesis of the Madi intrusion in the Huashi area, northern margin of the North China Craton: Implications for magma evolution and Nb–Ta mineralization","authors":"ChenYu Liu ,&nbsp;GongZheng Chen ,&nbsp;ChenChun Zhang ,&nbsp;JinFang Wang ,&nbsp;Guang Wu ,&nbsp;YingJie Li ,&nbsp;KangShuo Li ,&nbsp;ZeQian Lu ,&nbsp;YuTong Song","doi":"10.1016/j.oregeorev.2024.106261","DOIUrl":"10.1016/j.oregeorev.2024.106261","url":null,"abstract":"<div><div>Although the mineralization of rare earth elements (REEs) and rare metals is intimately associated with the extreme fractionation of granitic magmas, the metallogenic intrusions of many granite-hosted Nb–Ta deposits have undergone fluid–melt interaction. Nevertheless, the precise mechanisms by which fluid–melt interaction influences mineralization remain poorly understood. The present investigation examines the issues of the fluid–melt interaction in highly fractionated granites with Nb–Ta mineralization, utilizing data from the newfound Huashi deposit in the northern margin of the North China Craton (NNCC). The Huashi Nb–Ta–Rb–Li deposit hosted in the Madi intrusion consists of two lithologies that have evolved continuously, namely medium–fine grained granite (MGG) in the lower section and alkali-feldspar granite (AG) at the top. The ages of the MGG and AG were determined using LA–ICP–MS columbite U–Pb dating, yielding values of 182.9 ± 1.7 Ma and 184.7 ± 1.3 Ma, respectively. The Madi intrusion has high SiO₂, Al₂O₃, and total alkali contents, along with low CaO, MgO, MnO, and TFe₂O₃ contents and high Al₂O₃ / (CaO + Na₂O + K₂O) (A/CNK) values, classifying it as highly peraluminous granite with a high-K calc-alkaline affinity. Additionally, the intrusion also exhibits enrichment in Rb, U, Th, and Nb alongside significant depletion in Sr, Ba, Ti, Eu, and P, with a noticeable tetrad effect of REEs. The investigation of mica and feldspar minerals in the Madi intrusion using electron probe microanalysis (EPMA) indicates that the mica is mainly zinnwaldite, while the plagioclase belongs to albite. In summary, the Madi intrusion exhibits a highly I-type fractionated granite affinity. The extreme fractionation, intense fluid–melt interaction, and hydrothermal alteration of the intrusion contribute to the formation of the Huashi deposit.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106261"},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}