Ore Geology Reviews最新文献

{"title":"Stratigraphy, facies, and chemostratigraphy at the Palaeoproterozoic Rävliden North Zn-Pb-Ag-Cu VMS deposit, Skellefte district, Sweden","authors":"Filip Simán ,&nbsp;Nils Jansson ,&nbsp;Foteini Simistira Liwicki ,&nbsp;Erik Nordfeldt ,&nbsp;Mac Fjellerad Persson ,&nbsp;Lena Albrecht ,&nbsp;Christian Günther ,&nbsp;Paul McDonnell ,&nbsp;Tobias Hermansson","doi":"10.1016/j.oregeorev.2025.106489","DOIUrl":"10.1016/j.oregeorev.2025.106489","url":null,"abstract":"<div><div>Many base and precious metals are sourced from volcanic massive sulphide (VMS) deposits and understanding the geological characteristics of such deposits is crucial for new discoveries of this deposit type. Although key geological characteristics of modern VMS systems are relatively well understood, a remaining challenge is resolving the same geological characteristics in ancient, complex, altered and metamorphosed VMS deposits. One such deposit is the Palaeoproterozoic Rävliden North deposit, an 8.7 Mt (combined resources and reserves of 3.42 % Zn, 0.90 % Cu, 0.54 % Pb, 81 g/t Ag, and 0.24 g/t Au) replacement-style volcanic massive sulphide deposit in the felsic-bimodal western Skellefte district, northern Sweden. The VMS deposits in the Skellefte district are hosted in rocks subjected to greenschist to amphibolite facies metamorphism and occur at the lithostratigraphic contact between the metavolcanic 1.89 – 1.88 Ga Skellefte group (SG) and stratigraphically overlying metasiliciclastic 1.89 – 1.87 Ga Vargfors group (VG). Intense hydrothermal alteration commonly eradicates original rock textures, and polyphase deformation and metamorphism make geological interpretation and stratigraphic reconstruction difficult. Hence, to complement lithofacies analysis, immobile element chemostratigraphy is used in this study.</div><div>Rävliden North is predominantly hosted by felsic volcanic rocks of the herein defined Rävliden formation in the upper part of the SG that were deposited in half grabens related to rifting of a continental arc. Based on immobile elements and their ratios the felsic rocks fall into three groups, Rhy I, II and III. The chemostratigraphy and lithostratigraphy roughly coincide, where Rhy II (Zr/Al₂O₃ = 12.86, Al₂O₃/TiO₂ = 36.07, Zr/TiO₂ = 0.05) defines the rhyolites beneath the Rävliden formation that predominantly comprises Rhy I (Zr/Al₂O₃ = 17.23, Al₂O₃/TiO₂ = 32.33, Zr/TiO₂ = 0.06) and Rhy III (Zr/Al₂O₃ = 17.95, Al₂O₃/TiO₂ = 36.53, Zr/TiO₂ = 0.07), where Rhy I is the chief host to mineralisation. Mineralisation is partially hosted by graphitic phyllite that overlies the Rävliden formation and represents the base of the VG that indicates paused volcanism important for the build-up of massive sulphides beneath the seafloor. Facies analysis of rhyolites suggest that these were unconsolidated pumice rich rocks permeable for the upwelling hydrothermal fluids. Additionally, graphitic phyllite functioned as a permeability barrier inducing lateral fluid flow resulting in more effective sulphide precipitation.</div><div>This study demonstrates the effectiveness of combining stratigraphic, facies and chemostratigraphic analysis for targeting VMS deposits in complex, altered and metamorphosed rocks.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"178 ","pages":"Article 106489"},"PeriodicalIF":3.2,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395168","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":"Enrichment of rubidium and cesium in upper Triassic coals from the Cam Pha coalfield, NE Vietnam: Implications on sediment source and hydrothermal influence","authors":"Yang Lin ,&nbsp;Jing Li ,&nbsp;Xuanphu Nguyen ,&nbsp;Yuan Wang ,&nbsp;Vanlong Hoang ,&nbsp;Xinguo Zhuang ,&nbsp;Xin Luo ,&nbsp;Junyou Hou","doi":"10.1016/j.oregeorev.2025.106484","DOIUrl":"10.1016/j.oregeorev.2025.106484","url":null,"abstract":"<div><div>Research on critical metals in coal has aroused much interest because some coals are highly enriched in critical metals (Ge, Ga, Li, U, Nb, Ta, Zr, Hf, etc.), and consequently their corresponding coal combustion products may provide an alternative source for these elements. As two critical metals that plays important roles in a wide range of modern industries and various technological applications, Rb and Cs has been found enriched in the upper Triassic coal from the Cam Pha coalfield, NE Vietnam. However, the modes of occurrence and enrichment origin of Rb and Cs in the Cam Pha coal remains unclear. Based on the integrated mineralogical and geochemical analyses of the upper Triassic coals from the Duong Huy and Cao Son open-pit mines in the Cam Pha coalfield, this study focuses on investigating the enrichment and economic potential of rubidium and cesium in these coals. The Nos. 13, 14 and 15 coals from the Cam Pha coalfield are characterized by low-medium ash yield, low volatile matter yield and low sulfur content, belonging to anthracite. In comparison with the world hard coals, Rb and Cs is enriched in the No. 14 coal (Rb and Cs up to 142.8 mg/kg and 12.4 mg/kg, respectively) from Cao Son open-pit mine, as well as in non-coal rocks of No.13 coal (Rb and Cs up to 332.0 mg/kg and 26.4 mg/kg, respectively) and in the No. 15 coal from Duong Huy open-pit mine (Rb and Cs up to 128.5 mg/kg and 13.4 mg/kg, respectively). Rb and Cs mainly occur in K-rich aluminosilicates, such as muscovite in the three coal seams. The enrichment of Rb and Cs in coals from the Cam Pha coalfield is primarily ascribed to the terrigenous supply from the feldspar and mica-rich original felsic rocks in surrounding areas, which migrated into the coal basin through weathering processes during the coalification stage. The acidic anaerobic freshwater environments and the hydrothermal activity are also favorable for the enrichment of Rb and Cs in the study area. Rb and Cs are further enriched in coal fly ashes, reaching the industrial or marginal grade and presenting a promising economic potential for recovery of Rb and Cs from these coals.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"178 ","pages":"Article 106484"},"PeriodicalIF":3.2,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143289838","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":"Geochemistry of alteration and host rock lithologies to the Bisie tin deposit, North Kivu Province, DR Congo","authors":"Katharina Wulff ,&nbsp;Robert Bolhar","doi":"10.1016/j.oregeorev.2025.106469","DOIUrl":"10.1016/j.oregeorev.2025.106469","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Whole rock geochemistry is presented for lithologically-varied igneous and &lt;em&gt;meta&lt;/em&gt;-sedimentary rocks associated with the Bisie tin deposit, and combined with geochronological data and petrographic and field-based observations to develop insights into tectono-magmatic environment(s) of deposition as well physico-chemical conditions and timing of ore mineralisation.&lt;/div&gt;&lt;div&gt;Bisie tin mine, located in the Mesoproterozoic Kivu Belt (Democratic Republic of the Congo), is the world’s highest-grade tin mine (average grade 4.5 % Sn). Tin mineralisation consists of botryoidal cassiterite veins within an envelope of chlorite alteration, and is situated in a steeply east-dipping shear zone running parallel to the contact to a multi-phase granite massif. The hosting sequence comprises: A lowermost unit, hosting the tin mineralisation and containing mica schists with intercalations of sandstones, felsic tuffs and metabasaltic flows as well as (meta-)gabbro intrusions. Meter-scale pyrite-pyrrhotite-sphalerite-galena lenses of presumed &lt;em&gt;syn&lt;/em&gt;-sedimenatry exhalative origin are intercalated in the vicinity of the Bisie deposit. An overlying “metasedimentary unit” comprises tuffaceous shales, siltstones, sandstones and conglomerates. The uppermost unit consists of carbonaceous shales. Peak metamorphic grades in the mica schists are recorded by staurolite-garnet-biotite paragenesis, and decrease towards the top of the sequence and away from the granite massif based on the absence of metamorphic porphyroblasts in the carbonaceous shale. Along the shear zone, peak metamorphic parageneses retrogressed to muscovite (±chlorite) in an alteration zone with a length of &gt; 14 km, which also coincides with a soil Sn anomaly.&lt;/div&gt;&lt;div&gt;Zircon U-Pb information regarding the granitoid massif includes a granite age of 1518 Ma (pre-Kibaran), a marginal monzogranite age of 1274–1271 Ma and gneissic granite age of ca. 1000 Ma. Cassiterite from Bisie was previously dated at 1068–1029 Ma, consistent with formation during the G4 granite stage, associated with Sn, Nb-Ta, W and Au mineralisation across the Kibaride Belt.&lt;/div&gt;&lt;div&gt;Trace element signatures of the monzogranite as well as the metabasites indicate formation in an intraplate setting, consistent with deposition of central Kivu Belt rocks in an extensional basin during Cycle 2 of the Kibaran Orogeny. Compositions of the mica schist and carbonaceous shale indicate both collisional and rift environments, probably pointing to mixed sources. Similarity in trace element signatures prove that the chlorite schists, forming the alteration of the Bisie tin deposit, are alteration products derived from the hosting mica schists. All altered and unaltered metasedimentary samples as well as the monzogranite have positive Sn and negative Sr and Ba anomalies in Primitive Mantle normalisation, with the most pronounced anomalies observed in the chlorite schists, probably representing an alteration halo associated with","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"178 ","pages":"Article 106469"},"PeriodicalIF":3.2,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453985","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":"Geology, geochemistry, and zircon U-Pb geochronology of the Nanthila and Pedet granites in the Myeik Sn-W district, Tanintharyi region, southern Myanmar","authors":"Aye Pyae Phyo ,&nbsp;Huan Li ,&nbsp;Xiao-Jun Hu ,&nbsp;Majid Ghaderi ,&nbsp;Aung Zaw Myint ,&nbsp;Mohamed Faisal","doi":"10.1016/j.oregeorev.2025.106488","DOIUrl":"10.1016/j.oregeorev.2025.106488","url":null,"abstract":"<div><div>Critical metals, particularly tin and tungsten, are essential to global economic development and modern civilization. The Southeast Asian Tin Belt, extending 2800 km, represents the world’s most significant W–Sn metallogenic belt. This belt includes four metallogenic provinces: the Main Range Granitoid Province, the Northern Granitoid Province (North Thailand Migmatitic Province), the Eastern Granitoid Province, and the Western Granitoid Province), with ore assemblages predominantly associated with Phanerozoic intrusions. The Western Granitoid Province of southern Myanmar hosts numerous W-Sn mineralized granitoids, among which we investigated the Nanthila and Pedet granitic plutons in the Myeik Sn-W district. The study area consists primarily of the Carboniferous-Permian Mergui Group and Early Tertiary granitic rocks. The petrogenesis, tectonic setting, magmatic evolution, and the age of the Nanthila and Pedet granitic intrusions remain poorly constrained. This contribution reports field observations, petrographic studies, whole-rock geochemical analyses, in-situ U-Pb zircon dating, Lu-Hf isotopic data, and mineral chemistry analysis. Petrographic and geochemical data reveal that both plutons exhibit high SiO₂ (74.63–76.43 wt%), low CaO (0.62–0.73 wt%) and MgO (0.02–0.13 wt%) contents, elevated 10000*Ga/Al ratios (2.94–3.67), mildly peraluminous nature (A/CNK &lt; 1.1), and high-K calc-alkaline affinity. They show high HFSEs concentrations (Y: 8.1–14.8 ppm, Nb: 25.3–40.4 ppm, Th: 41.9–103 ppm, and U: 19.8–29.7 ppm) and moderate to high melting temperatures (zircon: 731–806 °C; apatite: 709–813 °C). These characteristics align with highly fractionated aluminous A₂-type granites, displaying “V” type REE distribution patterns with pronounced negative Eu anomalies. The Sn-related granitic magmas likely originated from the partial melting of clay-rich felsic crustal sources under reduced conditions and high temperatures in a post-collisional tectonic setting. Magmatic zircons from six granitoid samples yielded Concordia ages of ∼ 50.78 ± 0.47 Ma to 51.46 ± 0.43 Ma (Eocene period). The ¹⁷⁶Hf/¹⁷⁷Hf ratios (0.282271 to 0.282541), negative εHf(t) values (−7.18 to −16.74), and two-stage crustal model ages (T_DMC) (1.58–2.01) indicate derivation from Neoproterozoic continental crust. These findings highlight the potential of the Nanthila and Pedet areas for further geological investigation and mineral exploration, suggesting they could be promising sites for new reserves.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"178 ","pages":"Article 106488"},"PeriodicalIF":3.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148387","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":"Multi-stage granite and granitic pegmatites in the eastern North Qinling orogen: Petrogenesis, geodynamic setting, and metallogenic potential","authors":"Guochao Chen ,&nbsp;Xiaofei Zhang ,&nbsp;Xianzhi Pei ,&nbsp;Ruibao Li ,&nbsp;Zuochen Li ,&nbsp;Junqi Wei ,&nbsp;Rongzhen Zhang","doi":"10.1016/j.oregeorev.2025.106487","DOIUrl":"10.1016/j.oregeorev.2025.106487","url":null,"abstract":"<div><div>Numerous granitic pegmatite dikes intrude the Wuduoshan batholith in the eastern North Qinling orogen (NQ). However, the petrogenesis, interrelationships, and geodynamic setting of these granitoids and associated dikes remain poorly understood. This study investigates the Erlangchuan and Sikeshu plutons and their related dikes in the Qinling orogen, central China, through integrated petrographic, whole-rock geochemical, zircon U-Pb geochronological, and Lu-Hf isotopic analyses. Zircon U-Pb dating yielded crystallization ages of 430.8 ± 2.0 Ma for the Erlangchuan monzogranites, 415.2 ± 1.7 Ma for associated biotite granitic pegmatites, 416.9 ± 2.2 Ma for associated aplite dikes, and 403.6 ± 4.7 Ma for Sikeshu muscovite granitic pegmatites. All samples display geochemical characteristics consistent with a crustal origin, showing enrichment of large-ion lithophile elements (LILE; e.g., Rb, Th, Ba, and Cs) and depletion of high field strength elements (HFSE; e.g., Nb, Ta, and Ti). The granitic dikes exhibit higher SiO₂ contents compared to their respective host plutons: the K-rich Erlangchuan monzogranites and the Na-rich, two-mica Sikeshu granites. Zircon Lu-Hf isotopic data reveal higher ε_Hf(t) values for the Erlangchuan monzogranites (average = +2.6) compared to the associated biotite pegmatites (+2.0), aplites (+1.6), and the Sikeshu muscovite pegmatites (+0.9). The ε_Hf(t) values of both plutons and their dikes fall between those of the Qinling Group and juvenile mafic crust, suggesting derivation from a mixed source. Variations in ε_Hf(t) values likely reflect differing proportions of these two endmembers. The Erlangchuan monzogranites formed via partial melting of the lower crust, triggered by mafic magma underplating during Shangdan Ocean subduction. The Sikeshu two-mica granites, associated aplites, and biotite pegmatites likely formed during subsequent collision and slab break-off. Finally, the Sikeshu muscovite pegmatites may represent a later magmatic pulse related to post-collisional lithospheric delamination. Regionally, granitic pegmatites in the eastern NQ define three distinct age peaks at 437 Ma, 413 Ma, and 367 Ma. These pegmatites can be broadly classified into two series: (1) a rare metal-bearing series, predominantly located in the northern eastern NQ, enriched in Nb, Ta, Be, Rb, Li, and Cs, and characterized by negative ε_Hf(t) values indicative of a Qinling Group source; and (2) a U-bearing series, primarily found in the southern eastern NQ, positive or slightly negative ε_Hf(t) values, suggesting derivation from a mixed Qinling Group and juvenile crustal source.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"178 ","pages":"Article 106487"},"PeriodicalIF":3.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143289839","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":"Formation of the Miocene Weixi Sb-polymetallic mineralization in the Sanjiang Region, SW China: Insights from fluid inclusions, S-He-Ar isotopes, and zircon U-Pb geochronology","authors":"Yue-Fu Liu ,&nbsp;Hua-Wen Qi ,&nbsp;Wen-Jie Lin ,&nbsp;Lin-Kun Qi","doi":"10.1016/j.oregeorev.2025.106486","DOIUrl":"10.1016/j.oregeorev.2025.106486","url":null,"abstract":"<div><div>The Weixi Sb-polymetallic orefield (&gt;0.2 Mt Sb) in the Sanjiang metallogenic belt (northwestern Yunnan, SW China), represents a distinct type of Sb-polymetallic mineralization. Here, we examine the ore-fluid properties, source, and metallogenic process by analyzing the fluid inclusions, S-He-Ar isotopes, and zircon U-Pb age of three representative deposits (Shangnuluo, Baiji, and Hagudi) in the orefield. Early pyrite-molybdenite mineralizing fluids in the Baiji deposit contain A-type (liquid H₂O), B-type (gaseous CO₂), C-type (H₂O-CO₂), and D-type (solid-bearing) inclusions, showing a CO₂-rich, high-salinity (30.6–36 wt% NaCleqv.) fluid at medium–high temperatures (177–442°C), with metal precipitation primarily driven by fluid boiling. In the late sphalerite-galena-zinckenite-stibnite-calcite-quartz stage (Baiji), A-, B-, and C-type inclusions indicate lower temperatures (186–276.6°C) and salinity (0.35–12.4 wt% NaCleqv.), where metal deposition is controlled by fluid mixing. The Hagudi ore fluids are of medium–low temperature (150–368°C) and salinity (3.2–21.2 wt% NaCleqv.), contain primarily A-type (with some B-type) inclusions, with cooling and mixing being the main ore-forming mechanism. The Shangnuluo ore fluids are of medium temperature and low salinity, contain mainly A-, B-, and C-type inclusions (NaCl-H₂O-CO₂ fluid system), with immiscibility driving the metal precipitation. These fluid characteristics resemble typical orogenic or magmatic-hydrothermal ore fluids rather than basin-type ore fluids. He-Ar isotopes suggest a primarily crustal fluid origin with minimal mantle contribution. In-situ sulfur isotopes (Shangnuluo: −13.04 to −2.90 ‰; Baiji: −1.60 to 6.65 ‰; Hagudi: −2.48 to − 1.54 ‰) imply a magmatic and Permian formation source at Shangnuluo, magmatic and Jurassic formation source at Baiji, and a primarily magmatic source at Hagudi. Zircon U-Pb dating places the formation of ore-hosting quartz porphyry at Hagudi in the Late Permian (252.7 ± 2.4 Ma). The quartz porphyry was formed before the Miocene mineralization event (∼13 Ma) and potentially provided ore-hosting space for the Miocene mineralization.</div><div>Integrating our new data with previous studies on regional tectonics and magmatism, we speculate that the Weixi Sb-polymetallic mineralization is closely linked to concealed Miocene crustal magmatism. Ore-forming fluids migrated along faults into various stratigraphic levels, and metal precipitation was triggered by fluid immiscibility, cooling, and dilution by formation or meteoric water.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"178 ","pages":"Article 106486"},"PeriodicalIF":3.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422209","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":"Ore-forming process and ore genesis of the Wangu gold deposit in the Jiangnan orogenic Belt, South China: Constraints from pyrite textures, trace elements and in-situ sulfur isotopes composition","authors":"Minghui Chen ,&nbsp;Yongjun Shao ,&nbsp;Yongshun Li ,&nbsp;Zhongfa Liu ,&nbsp;Ke Chen ,&nbsp;Mingpeng He ,&nbsp;ZhaoHua Chen","doi":"10.1016/j.oregeorev.2025.106485","DOIUrl":"10.1016/j.oregeorev.2025.106485","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Jiangnan Orogenic Belt is an Au–Sb–W polymetallic metallogenic belt located between the Yangtze Block and Cathaysian Block, with a total proven gold resource exceeding 970 tons (t). The Wangu gold deposit (85 t Au @ 6.8 g/t) is one of the most representative gold deposits in northeastern Hunan Province, which is located in the central of the Jiangnan Orogenic Belt. Similar to many gold deposits in this region, multi-stage tectonic-magmatic-thermal events resulted in a complicated and confusing metallogenic process and genesis. Six pyrite types (Py-1 to Py-6) from five mineralization stages (Stage Ⅰ to Ⅴ) were systematically classified through detailed field investigation and sample observation in the Wangu gold deposit. Coarse-grained pyrite (Py-1) disseminated in slate has more dissolution holes in its core and a relatively homogeneous edge; milky white quartz veins crosscut slate, with a small amount of medium to fine grained pyrite (Py-2) disseminated in coarse-grained quartz; quartz-scheelite veins crosscut milky white quartz, but no other sulfides; medium- to coarse-grained pyrite (Py-3a) disseminated in altered slate far from the auriferous quartz veins is replaced by arsenopyrite, while the medium-grained pyrite (Py-3b) and arsenopyrite near the auriferous quartz veins are replaced by chalcopyrite, sphalerite, and galena; medium- to fine-grained pyrite (Py-4), arsenopyrite, and quartz-sericite veins crosscut quartz-scheelite veins; fine-grained quartz-pyrite (Py-5) veins crosscut quartz and sericite, typically having a granularity of less than 30 μm; calcite, quartz and pyrite (Py-6) veins crosscut quartz, muscovite and chlorite. The Au and As contents of Py-1, Py-2 and Py-6 are much lower than those of Py-3 (a, b), Py-4, and Py-5, and Au mineralization mainly occurs in altered slate and quartz-sulfide veins. Almost all types of pyrites have a lower Co/Ni ratio (&lt;1.0) and a higher As/Sb ratio (&gt;20), and are closely related to quartz, sericite, chlorite, calcite, and other hydrothermal minerals, indicating that they are of mainly hydrothermal origin. The presence of a large number of gold-bearing sulfides in altered slate indicate that wall-rock sulfidation and fluid boiling are the main precipitation mechanisms of Au in the Wangu goldfield. The δ&lt;sup&gt;34&lt;/sup&gt;S values of Py-1 (–11.33 to –10.42 ‰), Py-3 (3a: –9.68 to –6.98 ‰; 3b: –10.14 to –8.48 ‰) and Py-4 (–11.48 to –6.75 ‰) are similar, indicating that their sulfur may have been derived from metamorphic sedimentary strata (similar to the Lengjiaxi Group), and the relatively high δ&lt;sup&gt;34&lt;/sup&gt;S values (–5.69 to –2.66 ‰) of Py-2 may imply that its sulfur is predominantly from the deep ore-causative magmas (or magmatic sulfur involved). However, the lowest δ&lt;sup&gt;34&lt;/sup&gt;S values (–38.49 to –37.53 ‰) of Py-6 may reflect the reduction of metamorphic sulfur by bacteria. Py-1 and Py-2 (Au-poor and As-poor) have different sulfur sources, while Py-3 (a, b), Py-4, and Py-5 (Au-","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"178 ","pages":"Article 106485"},"PeriodicalIF":3.2,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387215","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":"Failed genesis of a Fe-skarn deposit caused by redox states of intrusion and wall rocks (Torre di Rio, Island of Elba, Italy)","authors":"Paolo S. Garofalo ,&nbsp;Daniele Redi ,&nbsp;Nikita Malafeevskiy ,&nbsp;Gunnar Schwarz ,&nbsp;Christoph Neff ,&nbsp;Peter Keresztes Schmidt ,&nbsp;Detlef Günther","doi":"10.1016/j.oregeorev.2025.106446","DOIUrl":"10.1016/j.oregeorev.2025.106446","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Torre di Rio skarn (Island of Elba, Italy) is a pyroxene-ilvaite-epidote skarn that hosts a Fe-oxide mineralization and is the type locality of the mineral &lt;em&gt;ilvaite&lt;/em&gt;. In contrast with other Fe deposits of the island, it belongs to a group of subeconomic skarns. We combine surface mapping, petrographic data, scanning electron microscope and electron probe microanalyses, fluid inclusion microthermometry, elemental imaging by Laser Ablation-Inductively Coupled Plasma - Time of Flight Mass Spectrometry (LA-ICP-TOFMS), and fluid-mineral equilibria to compare the genesis of this skarn with that of typical economic skarns.&lt;/div&gt;&lt;div&gt;Fieldwork shows that Torre di Rio consist of ilvaite-, ilvaite-pyroxene, and pyroxene-epidote zones. The epidote-rich zone is in contact with the wall rocks, i.e., a sequence of pelites, marls, marbles, and other sedimentary lithologies. The 6.53–5.9 Ma Porto Azzurro monzogranite is the reduced (ilmenite-bearing) causative intrusion of the skarn, which induced contact metamorphism in the wall rocks at 6.7–6.2 Ma. Torre di Rio formed within the biotite-white mica-chlorite metamorphic zone, a few hundred meters from the contact with Porto Azzurro.&lt;/div&gt;&lt;div&gt;Within the skarn, ilvaite and pyroxenes are both euhedral and arranged in rosettes and spheroids. Ilvaite has a consistent chemical composition with a significant Mn enrichment close to the wall rocks, and pyroxene is hedenbergitic. The epidote is euhedral and occurs as epidote s.s. and allanite-(Ce). Late phases are albite, annite, phengite, chlorite, quartz, calcite, and chalcedony. Magnetite and hematite form spheroid textures or are finely mixed. Euhedral pyrrhotite and pyrite host native Bi and Pb.&lt;/div&gt;&lt;div&gt;Seventeen calcite- and quartz-hosted fluid inclusion assemblages from the ilvaite skarn zones are associated with the magnetite and hematite aggregates. At room temperature, all assemblages are two-phase (L-V). Fourteen of them show constant phase proportions and three show variable proportions. The assemblages with constant phase proportions have salinities between 0.8 and 17.0 mass% NaCleq and homogenize by bubble disappearance between c. 150 and 300 °C. The assemblages with variable phase proportions homogenize by bubble and liquid disappearance between 280 and 330 °C.&lt;/div&gt;&lt;div&gt;Element imaging by LA-ICP-TOFMS of ilvaite and quartz from skarn spheroids shows that several lithophile (e.g., Al, Mg) and siderophile (e.g., As, Ge, Ga, In, Sb) trace elements occur at concentrations between c. 20 μg/g and 1 wt%.&lt;/div&gt;&lt;div&gt;We interpret our dataset as a product of a shallow skarn that formed under extremely reducing conditions, which were controlled by the redox nature of both Porto Azzurro and wall rocks. At these conditions, supersaturation of pyroxenes and ilvaite within the skarn was achieved as a result of phase separation, cooling, and mixing of batches of heterogeneous and homogeneous ore fluids at about 350–150 °C. A Fe-skarn deposit failed ","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"177 ","pages":"Article 106446"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149625","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":"Petrogenesis of the Dapingtianshan intrusive complex, South China: Geochemistry, zircon U-Pb geochronology, Sr-Nd-Hf-O isotopes, and implications for geodynamic setting and mineralization","authors":"Gang Chen ,&nbsp;M. Santosh ,&nbsp;Changhui Ke ,&nbsp;Maohong Chen ,&nbsp;Rui Ge","doi":"10.1016/j.oregeorev.2025.106449","DOIUrl":"10.1016/j.oregeorev.2025.106449","url":null,"abstract":"<div><div>The petrogenesis, tectonic setting and associated mineralization of magmatic suites associated with the subduction of the Paleo-Pacific plate have been topics of considerable debate. Hence, we explore the Dapingtianshan intrusive complex in South China, a composite intrusion with granodiorite in the margin and monzonite in the core. Geochemical features indicate typical I-type and high-K calc-alkaline characteristics, including abundant mafic microgranular enclaves (MMEs). Zircon U–Pb ages of 96.9 ± 0.3 Ma and 96.2 ± 2.9 Ma for the monzonite and MMEs suggest coeval magmatism. Biotite from both exhibits similar compositions, crystallizing at 700–750 °C. The monzonite and MMEs are metaluminous (A/CNK = 0.68–1.05), with trace element patterns showing enrichments in Rb, U, and Nd and depletions in Ba, Nb, Sr, P, and Ti. Chondrite-normalized REE distribution patterns reveal LREE enrichment and negative Eu anomalies. Zircon analyses show monzonite εHf(t) values of −2.4 to 0.6 and δ¹⁸O values of 5.6 to 8.6. MMEs exhibit εHf(t) values of −3.0 to 3.6. Sr-Nd isotopes suggest isotopic equilibrium during magma mixing, with (87Sr/86Sr)i of 0.70831 to 0.71426 and εNd(t) of −5.6 to −4.6. Findings suggest magma involvement of partial melts from the Mesoproterozoic metamorphic basement and enriched lithospheric mantle metasomatized by sediment-related melts linked to the subduction of the Pacific plate. Combining these results, we propose that the Dapingtianshan complex potentially hosts magmatic-hydrothermal Au–Ag–Cu–Pb–Zn metallogenic systems. The study hints at the extension of the Cu–Au metallogenic belt from the Dayaoshan area to the Qin-Hang metallogenic belt and South China.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"177 ","pages":"Article 106449"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149130","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":"Pyrite geochemistry for deposit type prediction and exploration in the Golden Triangle, northwest British Columbia, Canada","authors":"Christopher J.M. Lawley ,&nbsp;Duane C. Petts ,&nbsp;Well-Shen Lee ,&nbsp;Stefanie Brueckner","doi":"10.1016/j.oregeorev.2025.106447","DOIUrl":"10.1016/j.oregeorev.2025.106447","url":null,"abstract":"<div><div>Mineral exploration in remote mountain belts represents an exceptional challenge due to high operational costs, limited accessibility, and complex geology. New tools are urgently needed to improve discovery rates in these types of highly prospective but challenging mineral exploration frontiers. Herein we apply deep learning to predict deposit types in a rugged and remote part of northwest British Columbia (Canada) based on laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis of pyrite to address that knowledge gap. The combined pyrite dataset represents four mineral deposit types at various stages of development, including porphyry copper-gold (i.e., Galore Creek, Copper Canyon, Kerr, Mitchell, Sulphurets, Iron Cap), epithermal gold-silver (i.e., Brucejack), magmatic nickel-copper (i.e., E&amp;L), and volcanogenic massive sulphide copper-lead-zinc (i.e., A6). Trace element mapping, spot analysis, and quantitative mineralogy are applied to characterize the petrogenetic context and composition of each pyrite sample. Geochemical data were first pre-processed with principal component analysis and autoencoders to extract new features from the training data. The pre-processed pyrite data were then combined to train a series of feed-forward artificial neural networks to predict deposit types. The preferred deep learning classification model yields an overall accuracy of 99% for a subset of pyrite analyses that were not included in the training process. We then apply that classifier to show that hydrothermally altered rocks from early-stage mineral exploration projects (i.e., Dok and Yeti) are most likely related to porphyry copper-gold mineralization based on the composition of pyrite. Statistical analysis of the model results further demonstrates that pyrite morphology, texture, grain size, and paragenesis are important predictors of deposit type when combined with trace element concentrations and the new latent variables identified by the preferred autoencoder. We suggest that the pyrite library and modelling methodology can be used to support early-stage mineral targeting in remote exploration frontiers that are prospective for a range of deposit types.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"177 ","pages":"Article 106447"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149621","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}