Ore Geology Reviews最新文献

{"title":"Three-dimensional mineral prospectivity mapping using a residual convolutional neural network with lightweight attention mechanisms","authors":"Zhiqiang Zhang ,&nbsp;Gongwen Wang ,&nbsp;Emmanuel John M. Carranza ,&nbsp;Wei Li ,&nbsp;Yingjie Li ,&nbsp;Li Tang ,&nbsp;Xinxing Liu","doi":"10.1016/j.oregeorev.2025.106797","DOIUrl":"10.1016/j.oregeorev.2025.106797","url":null,"abstract":"<div><div>The continuous exploration and mining of surface and shallow mineral resources have promoted subsurface exploration. Over the past decade, mineral prospectivity mapping (MPM) has progressively expanded from two-dimensional (2D) to three-dimensional (3D). The 3D convolutional neural networks (CNN) and attention mechanisms (AMs) are adept at processing 3D voxel data, offering significant advantages for 3D MPM. However, the larger computational cost in a 3D CNN–AMs model presents limitations, constraining its application to 3D MPM. This study presents a new 3D CNN architecture composed of residual blocks (ResBlocks) and a lightweight Attention Mechanism (LAM) for 3D MPM. ResBlocks incorporate skip connections to deepen the network structure, thereby enhancing its ability to model complex nonlinear patterns and mitigating the vanishing gradient problem. The LAM utilizes the dimensionality reduction fully connected layer for channel attention and depthwise separable convolution for spatial attention, thus reducing computational costs. A case study in the Wulong gold district demonstrates that the proposed architecture achieves performance improvements in 3D MPM without significant increases in numbers of parameter count and FLOPs, highlighting its efficiency and effectiveness. Furthermore, the 3D mineral targets obtained in this study are beneficial for subsurface gold exploration in the Wulong Au district, China.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106797"},"PeriodicalIF":3.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The representativeness of in-situ sulfur isotopic results for sedimentary pyrite: Implications for tracing ore-forming fluids","authors":"Huiji Zhao ,&nbsp;Yanchao Han ,&nbsp;Rucao Li ,&nbsp;Xiao-Lei Wang ,&nbsp;Yuzhou Feng ,&nbsp;Chengming Wang ,&nbsp;Shitao Zhang","doi":"10.1016/j.oregeorev.2025.106811","DOIUrl":"10.1016/j.oregeorev.2025.106811","url":null,"abstract":"<div><div>The sulfur isotopic composition of sedimentary pyrite is frequently measured and compared with that of ore stage sulfides to assess the contribution of sulfur from sedimentary pyrite. In-situ analysis methods, notably secondary ion mass spectrometry (SIMS) and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), are both efficient and convenient for determining the sulfur isotopic composition of sedimentary pyrite and have been widely used in recent studies.</div><div>However, the representativeness of in-situ analysis results has rarely been investigated. In this study, we investigate this topic by analyzing sedimentary pyrite using SIMS. The samples were collected from the Meishan section in South China. The results show that framboidal and euhedral pyrite tend to have low and elevated δ³⁴S values, respectively. The average δ³⁴S value obtained by SIMS analysis is generally higher (up to ∼15 ‰) than that derived using bulk analysis in which pyrite was extracted using chromium reduction method. Since LA-MC-ICP-MS employs a larger spot size (25–50 μm), and only euhedral pyrite typically has a relatively large diameter, LA-MC-ICP-MS analysis would like yield even higher δ³⁴S values than SIMS. This suggests that in-situ sulfur isotopic results may not be fully representative of the sulfur isotopic composition of sedimentary pyrite.</div><div>A compilation of reported in-situ sulfur isotopic compositions of pyrite in the sedimentary host rocks in the “Golden Triangle” area shows that the average δ³⁴S value (∼+9‰) is significantly higher than those obtained through bulk analysis from South China and globally (&lt;−10 ‰), which is consistent with observation at Meishan.</div><div>Consequently, we suggest that combining bulk analysis, in which all the sulfur was extracted, with in-situ method, which provides sulfur isotopic compositions with detailed textural and temporal contexts, offers the most robust interpretation when tracing the source of sulfur in the ore-forming fluids.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106811"},"PeriodicalIF":3.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced prediction of deep-seated Cu-Mo porphyry mineralization: A comprehensive interpretation based on 2D inversion of audio-magnetotelluric data","authors":"Kouakou Assom Wilfried Kouabena ,&nbsp;Jin Zhou ,&nbsp;Rujun Chen ,&nbsp;Lingqiang Yin ,&nbsp;Hongzhu Cai ,&nbsp;Zhenyu Lu ,&nbsp;Jingchao Gu ,&nbsp;Wenbin Yu","doi":"10.1016/j.oregeorev.2025.106798","DOIUrl":"10.1016/j.oregeorev.2025.106798","url":null,"abstract":"<div><div>Copper and molybdenum are indispensable raw materials for modern industry and green energy. The rising demand and prices necessitate the exploration of new mineral resources. Porphyry copper-molybdenum (Cu-Mo) deposits are crucial suppliers of these metals, yet their deeper exploration (&gt;500 m) remains underexplored in the study area. Baohuashan is known for its intricate geological composition, rich in Cu-Mo porphyry. Previous exploration methods struggled to map extensive underground resources accurately. To solve this problem, this study utilizes Audio-Magnetotelluric (AMT) technology to investigate deep Cu-Mo porphyry deposits in Baohuashan, Jiangsu Province, China, aiming to address the challenges of accurately characterizing mineralization in this complex geological setting. We employed the AMT method, conducting two long survey lines with 50 AMT stations to explore and characterize the second-space of the space of the study area. We used a machine learning tools call watex to process the data, filtered the initial 53 frequencies used to collected and obtained 27 valid frequencies (10.16 Hz-1032 Hz). The adaptive-moving-average spatial filtering has been performed to rectify the static shift. Furthermore, we completed a transverse electric (TE) and transverse magnetic (TM) modes joint inversion using OCCAM2D inversion with a grid of 79 x 65 cells for both lines following a regularization factor selection criterion our parameters used. The two-dimensional models obtained by the robust data processing and inversion enhanced the detection and visualization of resistivity anomalies indicative of potential Cu-Mo deposits. Our results reveal distinct medium-resistivity (∼2500 Ω.m) structures at depths exceeding 500 m, likely associated with Cu-Mo deposits and regional faults (F2 and F15) oriented NE-SW and NW-SE, characterized by low resistivity. These findings suggest significant mineralization potential previously undetected by conventional methods. The presence of mineralization has been confirmed by three drill holes proposed and executed.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106798"},"PeriodicalIF":3.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144764154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magmatic-hydrothermal fluid evolution and genesis of the Machangqing porphyry Cu-Mo deposit, western Yunnan, China: Constraints from fluid inclusion and H-O-S isotopes","authors":"Wenyan He ,&nbsp;Liqiang Yang ,&nbsp;Nuo Sun ,&nbsp;Huaqing Wang ,&nbsp;Ruirui Zhang ,&nbsp;Shaoying Zhang","doi":"10.1016/j.oregeorev.2025.106812","DOIUrl":"10.1016/j.oregeorev.2025.106812","url":null,"abstract":"<div><div>The Machangqing Cu-Mo deposit is situated in the in western Yunnan (southwest China), which is tectonically located in the NW-trending Jinshajiang-Ailaoshan fold belt. The Cu-Mo vein mineralization is developed in altered wall rocks, associated with the Machangqing granite porphyry. Wall rock alterations include propylitic, phyllic, and potassic, and the alteration/mineralization veining comprises four major stages (I to IV): (I) pre-ore barren quartz; (II) early-ore quartz-sulfide (chalcopyrite + pyrite); (III) late-ore quartz-polymetallic (chalcopyrite + molybdenite + pyrite) sulfide; (IV) post-ore quartz-calcite. Four types of fluid inclusions (FIs) were recognized: liquid-rich two-phase (L-type), vapor-rich two-phase (V-type), hypersaline (H-type), and trace pure vapor (P-type). FI microthermometry suggests that the pre-ore (stage I) fluids were of relatively high temperature (375–510 °C) and salinity (48.2–62.8 wt% NaCl eqv.), with lithostatic pressure of 208–508 bars (eqv. 0.6–1.6 km depth); Fluid temperature may have decreased from <em>syn</em>-ore stage II (405 °C) to stage III (250 °C) fluids, with hydrostatic pressure of ∼100 bars (eqv. 0.9 km depth). Fluids obtained during the post-ore phase (stage IV) exhibited the minimum temperature (below 234 °C) and salinity (ranging from 1.1 to 3.2 wt% NaCl eqv.), indicating meteoric water incursion. We suggest that the stage I alteration occurred under alkaline and highly-oxidized fluid conditions (pH = 6.4–7.7; log<em>f</em>O₂ = -25.4 to –23.8), whereas stage II and III occurred under acidic and less oxidizing conditions (pH = 3.5–4.2; log<em>f</em>O₂ = -30.1 to −27.2). The ore fluid source may have transitioned from magmatic to meteoric, as evidenced by hydrogen–oxygen isotopes, whilst sulfur isotope compositions indicate a deep-seated magmatic source. We suggest that the Cu-Mo ore deposition at Machangqing deposit was triggered by decompression boiling, meteoric water incursion, and the consequent redox change at shallow (∼1 km) depth.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106812"},"PeriodicalIF":3.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overprinting of primary magmatic features by fluid-mediated processes in a F-bearing felsic rare-metal system: the Mueilha granite (Eastern Desert, Egypt)","authors":"Julie A.-S. Michaud ,&nbsp;François Holtz ,&nbsp;Daniel J. Kontak ,&nbsp;Simon Goldmann ,&nbsp;Martin Oeser ,&nbsp;Mohamed A. Abu El-Rus ,&nbsp;Ali A. Khudeir","doi":"10.1016/j.oregeorev.2025.106804","DOIUrl":"10.1016/j.oregeorev.2025.106804","url":null,"abstract":"<div><div>Fluids are major fractionation agents in granitic systems because they partly control the behaviour and partitioning of elements, including rare metals, during the magmatic-hydrothermal transition and their subsequent redistribution during the later subsolidus stage. The exsolution of magmatic fluids from a volatile-saturated magma and their subsequent circulation commonly result in important textural and geochemical changes with primary magmatic features being entirely overprinted and earlier minerals chemically re-equilibrated. The changes documented herein serve as a basis for tracking the equilibration of a rare-metal granite with interacting fluids. The Mueilha F-Nb-Ta-REE-Y granitic system (Eastern Desert of Egypt) is composed of different facies such as the “red granite”, representing the main volume of the intrusion, and the “border facies”, occurring along the red granite south-western margin. Detailed mineralogical and textural studies of the latter facies document the pervasive and intense transformation of the original highly-evolved granite primarily <em>via</em> coupled dissolution-precipitation. Based on these observations, and complementary whole rock, and mineral major and trace element chemistry, a complex five-stage model of evolution from magmatic to metasomatic is proposed and discussed. As part of this evolution, the border facies represents residual melts extracted at a very late stage of crystallization of the red granite. This process led to a selective enrichment in Nb and Ta, and a corresponding depletion in Li, F, REEs, and Y within the border facies, highlighting the critical role of the timing of extraction in shaping the composition of residual melts. It is suggested that the weak peraluminous character of the intrusion combined with its F content, albeit low (&lt;0.2 wt%), facilitated the observed autometasomatism and associated redistribution of rare metals and REE-Y within the intrusion to form magmatic and hydrothermal disseminated style mineralization typically encountered in rare-metal granites and pegmatites worldwide. We suggest that this study may serve as a useful reference point for investigating comparable settings elsewhere.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106804"},"PeriodicalIF":3.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron oxide copper–gold potential of Australia using a hybrid data- and knowledge-driven approach and its implications for the formation of IOCG mineral systems","authors":"J. Cloutier ,&nbsp;A. Ford ,&nbsp;D. Huston ,&nbsp;M. Haynes ,&nbsp;A. Schofield ,&nbsp;M. Doublier ,&nbsp;G. Sanchez ,&nbsp;J. Duan ,&nbsp;J. Goodwin ,&nbsp;E. Beyer ,&nbsp;G. Fraser ,&nbsp;Y. Cheng ,&nbsp;K. Waltenberg ,&nbsp;A. Burnham ,&nbsp;K. Czarnota","doi":"10.1016/j.oregeorev.2025.106802","DOIUrl":"10.1016/j.oregeorev.2025.106802","url":null,"abstract":"<div><div>Iron oxide copper–gold (IOCG) deposits are a globally significant source of copper and gold, and can also contain critical minerals required for the transition to a low-carbon economy. Given their economic and strategic importance, a national-scale assessment of the mineral potential for IOCG mineral systems in Australia has been undertaken using a hybrid data- and knowledge-driven approach. For the model, 149 mappable criteria were tested using the Kolmogorov-Smirnov test, and 14 criteria were identified to show a strong relationship with known IOCG mineralization and were retained for the model. The mineral potential model successfully predicts the location of 91.7 % of known IOCG deposits and occurrences in 8.3 % of the area, reducing the exploration search space by 91.7 %. Based on the statistical analysis, criteria related to energy sources are the most important, followed by ore depositional gradients, fluid pathways and architecture, and sources of metals, fluids and ligands.</div><div>The new national-scale model highlights several new areas of elevated prospectivity for IOCG mineral systems in under-explored regions of Australia. Based on their geological evolution, IOCG mineralization is probable in the Delamerian Orogeny, the Lamboo Province and the Tanami Orogen, possible in the Western Gawler Craton, the Hooper Province and the Musgrave Province, and unlikely in the Edmund Basin, Pilbara region and the Yilgarn Craton. This study highlights how precompetitive geoscience data can be evaluated and utilized within a geologically and statistically robust framework to produce mineral potential models with strong predictive performance.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106802"},"PeriodicalIF":3.6,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Skarn geochronology and genesis of the Wanlongshan Zn-Sn polymetallic deposit in southeast Yunnan: constraints from garnet and sphalerite composition, and in-situ S isotopes","authors":"Sun Bin ,&nbsp;Tian Peng ,&nbsp;Yan Yongfeng ,&nbsp;Liu Yi ,&nbsp;Kong Zhigang ,&nbsp;Yang Guangshu","doi":"10.1016/j.oregeorev.2025.106776","DOIUrl":"10.1016/j.oregeorev.2025.106776","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Wanlongshan Zn-Sn polymetallic deposit represents a significant deposit discovered recently in the world-class Dulong super-large Zn-Sn-In polymetallic ore field, situated in proximate to the Tongjie-Manjiazhai ore deposit. The stratiform to lenticular ore bodies are hosted within siliceous carbonate rocks of the Cambrian Tianpeng Formation’s second member and exhibit structural control by interlayer fault zones. Despite its importance, the precise timing of magmatic-hydrothermal activity and the associated ore-forming processes remain incompletely constrained, generating considerable debate regarding its genesis. To address these uncertainties, this investigation employs an integrated analytical approach combining garnet U-Pb geochronology, trace element geochemistry of garnet and sphalerite, and in situ sulfur isotope systematics. Geochemical analyses reveal that the garnets are predominantly grossularitic in composition, characterized by distinctive LREE depletion and HREE enrichment patterns that likely reflect the interplay between crystal-chemical constraints and adsorption mechanisms. The subdued europium anomalies suggest mineral formation under conditions of low oxygen fugacity within a weakly oxidizing to reducing environment that was neutral to mildly acidic, where hydrothermal metasomatism proceeded primarily via diffusional processes under restricted water/rock ratios. Geochronological constraints from garnet U-Pb dating yield an age of 88.1 ± 3.3 Ma (MSWD = 0.98, n = 17), which correlates remarkably well with molybdenite Re-Os ages from the mining district, ore formation ages at Manjiazhai, and the emplacement chronology of the Laojunshan granite. This temporal coincidence strongly indicates synchronicity among skarnization processes, Zn-Sn mineralization, and granitic magmatism. Trace element distributions in sphalerite reveal substantial enrichment in Fe, Mn, and In, with concomitant depletion in Ga, Ge, and Sn. Elemental ratios including Fe/Zn, Zn/Cd, and Ga/In in sphalerite indicate intermediate to high-temperature mineralization conditions. Multiple substitution mechanisms have been identified: Fe, Mn, and Cd incorporate through simple isomorphic replacement of Zn; Pb occurs predominantly as microinclusions; Cu enters as chalcopyrite solid solution; silver likely substitutes through coupled mechanisms involving either Ag&lt;sup&gt;+&lt;/sup&gt; + Ga&lt;sup&gt;3+&lt;/sup&gt; → 2Zn&lt;sup&gt;2+&lt;/sup&gt; or 2Ag&lt;sup&gt;+&lt;/sup&gt; + Ge&lt;sup&gt;4+&lt;/sup&gt; → 3Zn&lt;sup&gt;2+&lt;/sup&gt;; gallium exhibits minimal incorporation; while indium predominantly substitutes via Cu&lt;sup&gt;+&lt;/sup&gt; + In&lt;sup&gt;3+&lt;/sup&gt; ↔ 2Zn&lt;sup&gt;2+&lt;/sup&gt;.The trace element signature of sphalerite differs markedly from patterns characteristic of Mississippi Valley-Type (MVT), Volcanic-Hosted Massive Sulfide (VHMS), and Sedimentary Exhalative (Sedex) Pb-Zn deposits, instead exhibiting geochemical affinities with established skarn deposits worldwide. In situ sulfur isotope analyses yield δ&lt;sup&gt;34&lt;/sup&gt;S values rang","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106776"},"PeriodicalIF":3.2,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-supervised named entity recognition in low-resource domains: A case study of rare earth elements in coal","authors":"Pengfei Li,&nbsp;Wenze Lin,&nbsp;Yuqing Wang,&nbsp;Na Xu,&nbsp;Wei Zhu,&nbsp;Wei Liu","doi":"10.1016/j.oregeorev.2025.106796","DOIUrl":"10.1016/j.oregeorev.2025.106796","url":null,"abstract":"<div><div>Geological literature serves as a crucial repository of information for advancing geological understanding and guiding mineral exploration. However, manually extracting geological information from unstructured text is labor-intensive and inefficient. Named entity recognition (NER), a core task in information extraction (IE), offers an automated solution by identifying and classifying geological entities. While NER has been widely applied in geological fields, it remains limited in coal geology and coal-hosted critical metal deposits, which represent a typical low-resource domain. Therefore, this work proposes an efficient approach for the low-resource NER, using rare earth elements (REE) in coal as a representative case. An unlabeled text corpus is first collected from the Web of Science (WoS) database. Distant supervision and large language models (LLM) are then integrated to directly annotate part of the corpus. Domain experts subsequently validate and refine these annotations, yielding a high-quality labeled dataset for training the semi-supervised NER model. Specifically, four widely used NER models (i.e., BERT, BERT-CRF, BiLSTM-CRF, and BERT-BiLSTM-CRF models) are compared to identify the optimal model for self-training. This work focuses on seven geological entity types, including rock, mineral, element, maceral, location, stratum, and geologic time. Experimental results show that the BERT-CRF model achieves the best performance, with an F1-score of 0.8467. After applying the self-training algorithm, the F1-score improves to 0.8702, highlighting the effectiveness of the proposed approach in enhancing NER performance in the low-resource domain. Additionally, an entity-based literature retrieval system is developed to facilitate the accurate and efficient extraction of geological information from relevant sources.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106796"},"PeriodicalIF":3.2,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New insights into uranium source and mineralization process of the world-class jingchuan sandstone-hosted uranium deposit, ordos basin, China: Evidence from geology, carbonate textures and geochemistry","authors":"Yi-Han Lin ,&nbsp;Ming-Sen Fan ,&nbsp;Pei Ni ,&nbsp;Jun-Yi Pan ,&nbsp;Ruo-Shi Jin ,&nbsp;Yin-Hang Cheng ,&nbsp;Jian-Ming Cui ,&nbsp;Zhi-Lin Cheng ,&nbsp;Wen-Sheng Li ,&nbsp;Qiang Zhu ,&nbsp;Ying-Xing Zhu ,&nbsp;Zhao-Hui Li","doi":"10.1016/j.oregeorev.2025.106795","DOIUrl":"10.1016/j.oregeorev.2025.106795","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The world-class Jingchuan sandstone-type uranium deposit is situated in the Lower Cretaceous gray sandstone strata of the Luohe Formation, Ordos Basin, China, distinguished by its exceptionally thick orebodies (3–280 m) and extensive spatial distribution (about 2000 square kilometers), with relatively high ore grades of 4.3–17.4 kg/m&lt;sup&gt;2&lt;/sup&gt;, suggesting exceptionally high uranium reserves. Uranium mineralization is preferentially hosted within reduced gray sandstone zones that exhibit calcareous, ferruginous, and siliceous cementation. In contrast, the extensive red beds, present in the middle and lower parts of the gray sandstones, are generally barren of uranium. The uranium mineralization in basin sandstones is widely attributed to redox processes; however, the precise mechanisms and detailed processes involved remain undetermined. The presence of carbonates persists throughout the uranium mineralization process, effectively recording the properties of ore-forming fluids, mineralization processes, and precipitation conditions. This study integrates detailed petrographic observations with in situ geochemical analyses (LA-ICP-MS) to constrain the genesis of this exceptional uranium deposit. Three distinct types of carbonates have been identified: (1) highly rounded dolomite and calcite clasts (pre-ore stage; detrital grains; Type 1); (2) shell-like, euhedral microcrystalline, or cement-bound Fe-bearing dolomite (ore stage; spatially and genetically associated with uranium mineralization; Type 2); and (3) pore-filling sparry calcite (post-ore stage; formed during supergene fluid infiltration; Type 3). LA-ICP-MS analyses of the ore-stage carbonates (Type 2) reveal elevated U contents and prevalent existence of U-rich mineral inclusions, corroborating their direct association with U mineralization. Additionally, elevated total rare earth element (ƩREE) and phosphorus (P) concentrations in the Type 2 carbonates indicate mixture of oxidizing basinal fluid and reducing hydrocarbon-bearing fluid. Type 1 and Type 2 carbonates share similar chondrite-normalized REE patterns and Th/U ratios, indicating that the latter inherited its geochemical signature from the former. The similarity in geochemical signatures suggests that Type 1 carbonate clasts may have served as a source of uranium and other metals for the ore-forming fluids.&lt;!--&gt; &lt;!--&gt;In contrast, Type 3 shows a distinct geochemical signature, indicative of a different fluid source and a shift in the geochemical conditions during its formation. The combined geochemical (Y/Ho ratios, δCe values, and other trace element data) and mineralogical evidence suggest that the uranium mineralization may have originated from intra-basinal stratigraphic uranium-bearing carbonate clasts. We propose that prolonged interaction between oxidizing basinal fluids and these carbonate clasts resulted in the progressive enrichment of U, Fe, Mg, Ca, and other elements within the ore-forming fluids. Subsequent","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106795"},"PeriodicalIF":3.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial mediation on the development of the Molango manganese ore Deposits, Mexico","authors":"Joseph Madondo ,&nbsp;Ildikó Gyollai ,&nbsp;Krisztián Fintor ,&nbsp;Máté Szabó ,&nbsp;Szaniszló Bérczi ,&nbsp;Eduardo González Partida ,&nbsp;Carles Canet ,&nbsp;Elizabeth Chacon ,&nbsp;Sumit Mishra ,&nbsp;Márta Polgári","doi":"10.1016/j.oregeorev.2025.106782","DOIUrl":"10.1016/j.oregeorev.2025.106782","url":null,"abstract":"<div><div>The biggest manganese deposits in North America are found in the Kimmeridgian black shales of the Molango area, east-central Mexico. These deposits were generated during the Late Jurassic period when rifting related to the initiation of the Gulf of Mexico led to the development of carbonate platforms and inter-platform basins. Ore deposition occurred in a semi-restricted basin on a rimmed platform, where the inflow of oxygenated seawater ventilated the initially stagnant anoxic waters, resulting in the stratification of the basin. New evidence from sedimentary, mineralogical, and stable isotope analyses suggests that manganese ore deposits in the Molango district were formed through microbially mediated processes. Microbially mineralized biosignatures are developed through stromatolite-like, filamentous, and coccoid-like structures within the ore deposit, indicating that the precipitation of syngenetic Mn oxides and diagenetic Mn carbonates was in response to microbial metabolic activity. This microbial mediation is supported by negative δ¹³C value of the Mn carbonates and the simultaneous depletion of organic material in the ore zone, indicating a dominantly organic source for the carbon. The mineralization process involves a multi-stage bacterial activity to fix Fe and Mn from seawater. Subsequently, microbial enzymatic oxidation resulted in the development of poorly crystallized Fe and Mn oxides under oxygenic and suboxic conditions, respectively. During early diagenesis, the syngenetic Mn and Fe oxides reacted with organic material in the sediments through another microbially influenced process, resulting in the transformation of the oxides into carbonates, sulfides, and apatite. The alternating cyclic micro-laminae of different minerals resulted from cyclical changes in the dominant microbial groups between the iron and manganese oxidizing bacteria. The microbial metallogenic model for the Molango manganese deposits is similar to those established for other sedimentary manganese ore deposits worldwide, highlighting the crucial role microbial metallogenesis plays in their formation.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106782"},"PeriodicalIF":3.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}