Ore Geology Reviews最新文献

{"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":"Using combined texture-element-isotope indicators of sulfides to trace fluid mixing and evolution in Paleozoic IOCG system","authors":"Shuanliang Zhang ,&nbsp;Georges Beaudoin ,&nbsp;Liandang Zhao ,&nbsp;Lin Gong ,&nbsp;Weipin Sun ,&nbsp;Bing Xiao","doi":"10.1016/j.oregeorev.2024.106269","DOIUrl":"10.1016/j.oregeorev.2024.106269","url":null,"abstract":"<div><div>Geochemistry of sulfides is widely used to constrain sources and ore-forming processes of various mineral deposits. However, its application on Fe–oxide Cu–Au (IOCG) deposits is not well constrained due to multiphase pyrite and Cu minerals and their complex inheritance relationships. The Shuanglong deposit is an IOCG-like deposit in the Eastern Tianshan characterized by abundant Py1 and Py2 in the Fe mineralization stage (II) and Py3 and Py4 in the Cu mineralization stage (III). Chalcopyrite is divided into three types where Ccp1 is formed by replacing Py1 and Py2, Ccp2 coexists with Py4, and higher grade Ccp3 is in quartz–hematite–chalcopyrite veins without pyrite. Py1 and Py2 are associated with multiphase magnetite in stage II Fe mineralization, whereas Py3 coexists with the early epidote replaced by the late calcite–hematite–Py4–Ccp2 assemblage in stage III Cu mineralization.</div><div>The increasing Co contents and Co/Ni ratios and decreasing δ34S values (∼8‰ to 4 ‰) from core to rim in Py1 and Py2 indicate temperature and oxygen fugacity increases during the input of magmatic-hydrothermal fluids. Decreasing Co/Ni, increasing Au, and δ³⁴S_fluid (from ∼ 6 ‰ to 30 ‰) from Py3 to Py4 show fluid mixing between the magmatic-hydrothermal fluid and oxidized non-magmatic sulfur such as seawater or basinal brine sulfate during the stage III Cu mineralization. Ccp1 inherited its sulfur and certain trace elements such as Pb and Zn from pyrite, whereas the addition of external sulfur contributed to local high-grade Cu mineralization. Such external sulfur may be from the seawater or basinal brine sulfate, with an increasing contribution during precipitation of Ccp2 and Ccp3 shown by fluid δ³⁴S values (from 26 ‰ to 36 ‰). Combined with the decreasing Cd/Zn ratios from Ccp1 to Ccp3 caused by increasing total sulfur in fluids, this suggests that the sulfate sulfur contribution may have played a significant role in the high-grade Cu mineralization in IOCG deposits. This study also highlights the importance of the detailed texture of pyrite using acid etching, coupled with <em>in-situ</em> sulfur isotope and trace elements of pyrite and chalcopyrite for IOCG deposit research.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422367","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":null,"pages":null},"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}

{"title":"Contribution of bismuth melts to gold endowment in the Baolun gold deposit, Hainan Island, South China","authors":"Shuang Yan ,&nbsp;Qiang Shan ,&nbsp;Deru Xu ,&nbsp;Xueyuan Yu","doi":"10.1016/j.oregeorev.2024.106258","DOIUrl":"10.1016/j.oregeorev.2024.106258","url":null,"abstract":"<div><div>Bismuth (Bi) melts and related polymetallic alloys can efficiently scavenge gold (Au) from Au-unsaturated aqueous solutions, contributing to the Au endowment in many hydrothermal deposits. However, original evidence for Au–Bi melts is often poorly preserved due to post-precipitation alteration. This complicates investigation of the liquid bismuth collector model in hydrothermal Au deposits. Here we present primary evidence for the occurrence of Au–Bi melt in hydrothermal systems through an examination of the Au–Bi phases and textures in the Baolun Au deposit (Hainan Island). This study found that maldonite, native bismuth, Au–Bi symplectite and Au–Bi melt blebs appeared successively following the precipitation of native gold. Notably, large Au–Bi melt blebs were well preserved in natural systems due to the rapid cooling of fluids. The mineral assemblages and their corresponding fluid physiochemical conditions suggest that the evolution of the ore fluids at Baolun was characterized by a continuous reduction in Au and Bi concentrations and Au/Bi ratios alongside decreasing fluid temperatures and sulfur fugacity (<em>f</em>S₂). These observations offer direct evidence for Au scavenging by Bi melts in a mesothermal (275–450 °C), low-<em>f</em>S₂ and reduced hydrothermal system, aligning well with the Au–Bi binary phase evolution established in metallurgy. As the fluid cooled further, the Au–Bi phases were subsequently overprinted by later Te–S-rich fluids, as evidenced by the formation of bismuthinite, jonassonite, and joséite-A around the Au–Bi phases. Importantly, our study reveals that the Baolun Au deposit is<!--> <!-->characterized<!--> <!-->by a Au–Bi–Te hydrothermal system and that the metamorphic country rocks at Baolun are the major source of Au, Bi, and Te.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322396","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 and decoupling controls of Sn-(Ta-Li) and W-(Sn) mineralization in the Iberian Variscan Massif, Spain and Portugal","authors":"Iñigo Borrajo ,&nbsp;Fernando Tornos ,&nbsp;Holly Stein ,&nbsp;John M. Hanchar","doi":"10.1016/j.oregeorev.2024.106253","DOIUrl":"10.1016/j.oregeorev.2024.106253","url":null,"abstract":"<div><div>Sn-W mineralization in the Iberian Variscan Massif (corresponding with the western zone of the Iberian Peninsula, in Spain and Portugal) occurs closely related to metaluminous to peraluminous granitoids of Variscan age. The deposits are grouped into two main styles of mineralization; Sn-(Ta-Li) and W-(Sn) deposits. Within this work we present a first attempt to correlate timing of W-Sn mineralization and plutonic events at a regional scale. We report new ⁴⁰Ar/³⁹Ar dates of muscovite related to the quartz-muscovite alteration of eleven deposits, molybdenite Re-Os dates from six deposits and two new zircon U-Pb dates of granitoids genetically related to the mineralization. The dates obtained support the relationship between W-Sn mineralization with specific, but not uniquely just one, granite suites. The dominant S-type peraluminous Variscan granitic suites in Iberia, the S₁-type dated at ca. 330–311 Ma and the S₂-type at ca. 314–296 Ma, are related to both, Sn-(Ta-Li) and W-(Sn) mineralization. A subgroup of deposits of the W-(Sn) group, generally enriched only in W but not in Sn is associated with the youngest but volumetrically less abundant I-type (ca. 303–280 Ma) metaluminous magmatism. The relationship of both the Sn-rich and W-(Sn)-rich deposits with the highly peraluminous S-type granites suggest that the ultimate source of the melts is not related to the decoupling between Sn and W. Therefore, the causes of W and Sn separation may be related to late-stage magmatic and magmatic-hydrothermal processes.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S016913682400386X/pdfft?md5=a7fa4aac9924e7d0087b16b9a80237d9&pid=1-s2.0-S016913682400386X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312594","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":"Metallogenesis of uranium deposits in China: Perspectives from uraninite chemistry","authors":"Long Zhang ,&nbsp;Fangyue Wang ,&nbsp;Taofa Zhou ,&nbsp;Jingjing Zhu ,&nbsp;Chenyuan Cao","doi":"10.1016/j.oregeorev.2024.106251","DOIUrl":"10.1016/j.oregeorev.2024.106251","url":null,"abstract":"<div><p>Uraninite is generally the most principal component of uranium ores and can record the significant information about uranium mineralization processes. Here, chemical compositions of uraninites from thirty-five uranium deposits of nine types (including granite-related, sandstone-hosted, volcanic-related, black shale-hosted, Na-metasomatite-hosted, peralkaline syenite-hosted, pegmatite-hosted, carbonatite-hosted, and leucocratic dyke-hosted) in China were examined, with the aim to investigate the chemical variations of uraninite from each deposit type and fingerprint uranium metallogenesis. Uraninites from the last five types contain significant abundances of ThO₂ (median = 3.81 wt%), Y₂O₃ (0.96 wt%), and ∑REE (typically ≥ 1 wt%) and low concentrations of Si, Fe, and Ca (SiO₂ + CaO+FeO typically &lt; 1 wt%) and have middle rare earth elements (MREE)-enriched chondrite-normalized REE patterns with pronounced negative Eu anomalies, although the carbonatite-hosted type shows insignificant Eu anomaly. These characterize the affinity of intrusive-related deposits that formed at high temperatures. Uraninites from granite-related deposits generally contain negligible abundances of Th and Y, the highest CaO (up to 9.89 wt%), and highly variable ∑REE concentrations. Their chondrite-normalized REE patterns typically resemble those of the host granites, suggesting that the REE signatures were mainly controlled by the sources of REE (U). Uraniferous phases from sandstone-hosted deposits have the lowest concentrations of UO₂ (median = 66.87 wt%) and the highest SiO₂ (up to 21.63 wt%), FeO (15.72 wt%), Y₂O₃ (10.35 wt%), and P₂O₅ (9.69 wt%) and generally show LREE-enriched REE patterns, which are indicative of the predominant role of LREE-rich sources in the mineralization. In contrast, those particles characterized by flat REE patterns probably suggest the involvement of hydrothermal fluids in the mineralization. Although uraninites from black shale-hosted uranium deposits have a LREE-rich source-controlled REE pattern, they are poor in P and Y and rich in W, which can discriminate them from the sandstone-hosted type. Uraninites from volcanic-related uranium deposits have variable REE signatures, suggesting the various formation conditions from which the uraninites form. Our study indicates that uraninite chemistry can help constrain the genesis of uranium deposits and discriminate deposit types.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003846/pdfft?md5=d86882059175fc3efcb0c5d542b38be4&pid=1-s2.0-S0169136824003846-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271516","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":"Estimating rare earth elements at various scales with bastnäsite indices for Mountain Pass","authors":"Otto C.A. Gadea,&nbsp;Shuhab D. Khan,&nbsp;Virginia B. Sisson","doi":"10.1016/j.oregeorev.2024.106254","DOIUrl":"10.1016/j.oregeorev.2024.106254","url":null,"abstract":"<div><div>Numerous researchers are exploring innovative ways to map rare earth elements (REEs) critical to components in high technology devices precisely, and one approach that has made significant advances in recent years involves imaging spectroscopy. This research focuses on the utilization of this technique to map REEs across the Sulfide Queen mine and Birthday claim area located in Mountain Pass, California, where the highest concentrations of REEs within a carbonatite deposit in the United States have been reported. New spectral indices based on reflectance measurements of eleven representative ore samples under visible illumination in a laboratory setting were developed and applied to data collected by eight airborne and spaceborne imaging spectrometers. The results show that these indices can effectively detect REEs in any rock formation where an adequate amount of rare earth fluorocarbonates have accumulated. Identification can be achieved using airborne and spaceborne hyperspectral sensors with a spatial resolution of up to 30 m. Geochemical analyses confirm that a REE+Y ore grade of 3.25 wt% or greater is sufficient for detection using these indices.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320325","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":"Geochemical characteristics of olivine and clinopyroxene in parental mafic–ultramafic rocks from the Yuanshishan Ni-Co laterite deposit in Qinghai Province, NW China","authors":"Yu-Qing Jiang ,&nbsp;Shao-Yong Jiang ,&nbsp;Hui-Min Su ,&nbsp;Wenqi Ren ,&nbsp;Hua Li ,&nbsp;Shuyue He","doi":"10.1016/j.oregeorev.2024.106252","DOIUrl":"10.1016/j.oregeorev.2024.106252","url":null,"abstract":"<div><div>Yuanshishan is a Ni-Co laterite deposit that occurs in the Lajishan tectonic zone of the South Qilian orogenic belt, NW China. Ni–Co mineralization took place during the weathering of the parental mafic–ultramafic rocks. Little is known about the petrogenesis of these parent rocks. Therefore, field and petrographic investigations, together with <em>in situ</em> major and trace element analyses, were carried out on olivine and clinopyroxene from unweathered mafic–ultramafic rocks in the Yuanshishan Ni-Co deposit. The results show that olivine (Ni 963–2674 ppm, Co 52.7–245 ppm) is richer in Co and Ni than clinopyroxene (Ni 155–203 ppm, Co 23.1–32.5 ppm) in the Yuanshishan mafic–ultramafic rocks. The chromite (Ni 98.8–892 ppm, Co 836–1062 ppm) show higher Co and Ni than clinopyroxene, but has lower Ni but higher Co than olivine. Therefore, olivine and chromite are two main Co and Ni rich minerals in the parent rocks of Yuanshishan. A compositional comparison of olivine and clinopyroxene from the Yuanshishan deposit to those from other magmatic sulfide deposits reveals that the Yuanshishan parent magma is relatively poor in Ni and rich in Co. Olivine in the dunite of Yuanshishan has a quite high Fo value (95.2–98.3). The Yuanshishan olivine grains also show a positive correlation between Ni content and Ni/Co or Co content, and the correlation with Fo value is not obvious. The Co content shows a negative correlation with the Ni content and Fo value, which are consistent with the mantle olivine characteristics. Furthermore, the Li, Sc, V contents in olivine are lower than 10 ppm, indicating that the magma originated from the mantle. The Al, Si, Ti, Ca, and Na contents in clinopyroxene indicate that the original magma may have been subalkaline basaltic melt. Using an olivine-spinel thermometer, the Yuanshishan magma crystallization temperatures are calculated to be 1256–1376 °C. The Al^Ⅳ:Al^Ⅵ ratio (0.7–6.0) and Eu/Eu* value (0.9–1.4) of the clinopyroxene indicate that the Yuanshishan mafic–ultramafic rocks were formed under conditions of low to medium pressure and high oxygen fugacity. Moreover, the geochemical discriminant diagrams of clinopyroxene indicate that these rocks possibly formed in an island arc setting.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322395","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}