Ore Geology Reviews最新文献

{"title":"Exploration and mining of lateritic gold (Part II): Resource estimation, geometallurgy and environmental considerations","authors":"","doi":"10.1016/j.oregeorev.2024.106207","DOIUrl":"10.1016/j.oregeorev.2024.106207","url":null,"abstract":"<div><p>This study examines the resource evaluation and processing of gold in the ferruginous gravels and duricrust (FGD) deposits, encompassing lateritic residuum or similar ferricrete. Evaluating lateritic gold deposits presents significant challenges, leading to variability and bias in results, particularly in the low-grade ranges that often characterize these deposits. The surveyed technical reports reveal that FGD deposits generally contribute less than 10% to total deposit resources, comprising only about 5 wt% of their total gold content. Limited exploration in lateritic domains may underestimate the size and grade of gold deposits in the lateritic environment. Expanding the number of drill holes over larger areas can yield significantly higher resource estimates than those derived from restricting exploration to zones directly above the primary mineralization. Of the 63 projects surveyed for this study, 45% defined a lateritic domain, yet only 30% progressed to the resource evaluation phase. Discrimination of domains improves resource estimates and significantly impacts mining operations, notably enhancing metallurgical recovery. Bulk cyanidation tests indicate that rapid leaching kinetics contribute to high gold extractions (95–97%) in lateritic samples. While gravimetric gold recoveries are lower for FGD deposits and oxidized materials than transition and sulphide domains, the opposite is observed in leaching. This behavior is likely due to greater cyanide accessibility and the morphology of secondary gold grains. Operating costs for lateritic deposits are lower than those for primary mineralization, despite variability in mining costs. Processing costs for lateritic gold projects are generally similar, regardless of the apparent compositional differences. From an environmental perspective, lateritic projects with low stripping ratios and increased rock friability may have smaller carbon footprints. However, uncertainties arise in the water footprint due to clay-rich tailings’ potential for non-recoverable water consumption. The analysis of public reporting of lateritic deposits shows a need for more rigor in characterizing and evaluating these deposits. Most mining operations on weathered ores require more detailed studies to ensure good practices and international quality standards. Therefore, a revised model for lateritic gold deposits with a new perspective, including in their technological, economic, and environmental settings, based on operational sustainability thinking, is required for the global gold mining industry.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003408/pdfft?md5=7b7a25a24e27432f42e5c6fcd06135e4&pid=1-s2.0-S0169136824003408-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142098980","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":"Tungsten enrichment processes in peraluminous granites of the Chinese Altai","authors":"","doi":"10.1016/j.oregeorev.2024.106211","DOIUrl":"10.1016/j.oregeorev.2024.106211","url":null,"abstract":"<div><p>To evaluate the processes facilitating the W enrichment in peraluminous granites, three peraluminous granitic intrusions in the Chinese Altai have been investigated. The Yilaike pluton and Tielieke batholith are dominated by biotite granite with subordinate muscovite granite, while the Shangkelan pluton is of A-type granite characteristics and comprised mainly of muscovite granite and topaz-albite granite. The Yilaike pluton, Tielieke batholith and Shangkelan pluton were generated in Late Ordovician (444–447 Ma), Early Devonian (402–406 Ma) and Late Triassic (204 Ma), respectively and possess high-K calc-alkaline and peraluminous composition as well as low oxygen fugacity. All the intrusions underwent fractional crystallization and hydrothermal processes of various extents, and the Shangkelan pluton, among others, is the most striking in hydrothermal alteration. The Yilaike and Tielieke granites have similar εNd_(t) (−4.9 to + 0.3 and −2.4 to + 0.7, respectively) and whole-rock δ¹⁸O (+11.6 to + 15.3 ‰ and + 10.4 to + 13.2 ‰, respectively) values, consistent with an origin of the Early Paleozoic metasedimentary rocks in the Chinese Altai. The Shangkelan granites possess incompatible element ratios and trace element variation trends different from those of the Yilaike and Tielieke granites, and their relatively radiogenic εNd_(t) (−0.1 to + 0.4) values, low δ¹⁸O (+10.1 to + 12.0 ‰) ratios and F-rich muscovite indicate that the Shangkelan granites were probably formed by partial melting of a biotite-rich igneous protolith. The biotite granite of the Yilaike pluton and Tielieke batholith contains low W (0.8–1.2 ppm) equivalent to that of the Early Paleozoic metasedimentary rocks, suggesting a limited efficiency for W transport from the source into partial melts. A pronounced rise of W content in the Yilaike and Tielieke granites (up to 11 and 35 ppm, respectively) occurred during the evolution towards muscovite granite, indicating the contribution of magmatic and hydrothermal processes. The Mesozoic Shangkelan pluton contains the highest W (up to 235 ppm) among these intrusions. The most striking W enrichment occurred in a pseudo-greisen stage characterized by formation of F-rich Li muscovite, which reflects the effect of hydrothermal alteration. Meanwhile, the lowest W concentration (ca. 8 ppm) of the Shangkelan pluton is remarkably higher than that of the Early Paleozoic metasedimentary rocks, implying a relatively high initial W content in its igneous protolith that probably formed in previous crustal reworking. The study demonstrates that repetitively melting of an immature crustal source can significantly increase the W abundance in the resultant peraluminous granites.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003445/pdfft?md5=6b424d716cff598957202ccc8eb06c3a&pid=1-s2.0-S0169136824003445-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142087661","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":"Overcoming survival bias in targeting mineral deposits of the future: Towards null and negative tests of the exploration search space, accounting for lack of visibility","authors":"","doi":"10.1016/j.oregeorev.2024.106214","DOIUrl":"10.1016/j.oregeorev.2024.106214","url":null,"abstract":"<div><p>Broad consensus exists amongst mineral explorers that most outcropping mineral deposits have been found. The next generation of discoveries will rely on our ability to recognize the subtle or cryptic signals of deep-seated deposits. Exploration targeting under such conditions requires greater knowledge of the processes that formed the targeted mineral deposit types and new or improved exploration methods designed to effectively test for buried mineralization. Survival bias is a form of selection bias that is defined as the logical error resulting from neglecting data or information because of their “lack of visibility”. In this study, “lack of visibility” refers to situations where (i) mineral explorers ignore or overlook particular terrain because it lacks or contains only weak signals of a mineralizing system, and (ii) such areas are excluded from further exploration as the existing data or information neither confirm nor support the targeting model. Therefore, it is critical to more comprehensively analyze a search space to more confidentially determine whether a terrain without the desired targeting signals satisfies the criteria of a null or negative test. The idea for this study is based on the notion that if a buried mineral deposit was present in an overlooked terrain it would nevertheless comprise distinctive geological features and targeting signals to guide the explorer, although, more likely than not, these signals would be very weak. Here we used a porphyry copper (Cu) district in Iran to explain and illustrate the adaptation of the survival bias concept. More specifically, in this study we tested the usefulness of a recently proposed targeting criterion, namely sites of potential focused fluid flux, as an input to mineral prospectivity analysis and exploration targeting. The findings of our study have implications for the future development of regional- to global-scale exploration information systems (EIS), designed to improve the performance of mineral exploration targeting.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003470/pdfft?md5=e8e867caef04d5b6fde38b013a656773&pid=1-s2.0-S0169136824003470-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044494","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":"Effects of phosphatization on the mineralogical and geochemical composition of marine ferromanganese crusts from the JiaXie Guyot in the Western Pacific: Constraints from high resolution analysis","authors":"","doi":"10.1016/j.oregeorev.2024.106209","DOIUrl":"10.1016/j.oregeorev.2024.106209","url":null,"abstract":"<div><p>The marine crusts comprise ferromanganese sediments formed through the precipitation of dissolved elements in seawater. These crusts serve as a record elements signal from paleo-ocean and are extensively utilized in paleo-oceanography. Previous researches have examined the chemical composition of the phosphatized crust layers using powder chemistry and leaching experiments. However, there exist divergent viewpoints regarding the influence of phosphatization on element behavior. In this study, we employed a combination of analytical techniques including scanning electron microscope (SEM), powder X-ray diffractometer (XRD), TESCAN Integrated Mineral Analyzer (TIMA), laser ablation and inductively coupled plasma time of flight mass spectrometry combined system (LA-ICP-TOF), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). These methods were utilized to achieve mineral phase quantification, precise depiction of element distribution, and in-situ profile analysis of elements within the phosphatized crust layers from the JiaXie Guyot in the Western Pacific. The mineral phase analysis shows enormous carbonate fluorapatite (CFA) precipitate, which replace calcite in the old phosphatized layer. Additionally, vernadite experiences partial dissolution. Furthermore, a small amount of hematite, goethite, todorokite, zeolite, barite, as well as trace amounts chalcopyrite, sphalerite, galena, ilmenite, and pyrite are formed. The element distributions suggest potential outward migration of Fe, V, Zr, Zn and Cu, while Ce and Pb are locally enriched. In the phosphatized crust, some elements exhibit depletion in the old crust layer compared to the young crust layer, with Fe &gt; Si &gt; V&gt;Zn &gt; Ti ≥ Pb, while others are enriched in the order crust layer, such as Y&gt;Pd &gt; Ce &gt; Pt. The study proposes that FeOOH·nH₂O and associated adsorbed elements like Si, Ce, Y, V, Zn, Ti and Pb dissolve in vernadite and migrate outward during phosphatization, with weak phosphatization influence on Mn oxide. In addition, the phosphate-rich seawater might contribute additional elements such as Y, Ce and Pd to the crust layers. Thus, this study highlights the elemental distributions, migration patterns observed, and significance of presence for critical metals between old and young crust layers from the influence of phosphatization based on high resolution analysis. Particularly, it acknowledges the contribution of phosphate-rich seawater to the elemental composition of crust layers.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003421/pdfft?md5=e6650c79b8be67076cb29ef97474ce25&pid=1-s2.0-S0169136824003421-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142049365","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":"Occurrence and enrichment of cobalt and nickel in the Yindongshan ultramafic–mafic intrusion-hosted iron deposit, western Hubei Province, China","authors":"","doi":"10.1016/j.oregeorev.2024.106213","DOIUrl":"10.1016/j.oregeorev.2024.106213","url":null,"abstract":"<div><p>The Yindongshan iron deposit in western Hubei Province of China is hosted within Ordovician ultramafic–mafic intrusions. Recent field geological surveys have detected cobalt (Co) and nickel (Ni) enrichment within the Yindongshan clinopyroxenite, suggesting good potential for subeconomic Co-Ni mineralization. This study investigated the occurrence modes and enrichment processes of Co and Ni in the Yindongshan deposit through field geology and <em>in situ</em> analysis of the rock texture, geochronology, and geochemistry of sulfides, Fe-Ti oxides, and silicate minerals. The Yindongshan clinopyroxenites were emplaced at 440.2 ± 7.2 Ma via titanite LA-ICP-MS U-Pb dating, and underwent extensive post-magmatic metamorphism at 401.2 ± 8.6 Ma via apatite U-Pb dating. This metamorphism led to the widespread formation of amphibole via the replacement of clinopyroxene. Subsequently, hydrothermal epidote-albite veins, calcite-pyrite veins, and later actinolite veins developed. Pyrites from both clinopyroxenites and calcite veins show limited δ³⁴S variations from −5.4 ‰ to −1.2 ‰, suggesting a magmatic sulfur source. Late-vein actinolites display geochemical characteristics distinct from those of amphiboles, indicating possible involvement of external fluids. LA–ICP–MS trace element results reveal a general increase in Co and Ni contents from silicate minerals and Fe-Ti oxides to pyrite and from earlier-crystallized coarse-grained clinopyroxenite to later medium- to fine-grained clinopyroxenite. The highest Co and Ni contents observed in pyrite from coarse-grained clinopyroxenite suggest their preferential incorporation into early sulfide minerals and then progressively depleted through magmatic evolution such as fractional crystallization. The positive correlation between Co and Ni with Fe in pyrite, along with the consistent parallel time-resolved LA–ICP–MS depth profiles among different mineral phases, indicates that isomorphic substitution occurred in pyrite. In silicate minerals, the Co and Ni contents increase from pyroxene, amphibole, to actinolite, with almost no Co or Ni present in epidote. The elevated Co and Ni contents in metamorphic amphiboles are attributed to their remobilization from magmatic pyrite to newly formed amphiboles. During the late hydrothermal phase, external fluids might transport additional Co and Ni, contributing to higher concentrations in late actinolite veins. In general, Co and Ni in the Yindongshan iron deposit are primarily hosted in sulfide minerals and can be remobilized during regional metamorphism and metasomatism. Thus, magmatic iron or iron–titanium oxide deposits hosted by mafic–ultramafic intrusions with sulfide mineralization may serve as promising targets for further Co-Ni exploration.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003469/pdfft?md5=d96862876ca616cbb5e8e2cb3eff6807&pid=1-s2.0-S0169136824003469-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142049366","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":"Audio magnetotelluric view of the giant carbonatite-hosted Bayan Obo REE deposit, Inner Mongolia, northern China","authors":"","doi":"10.1016/j.oregeorev.2024.106208","DOIUrl":"10.1016/j.oregeorev.2024.106208","url":null,"abstract":"<div><p>As critical minerals in low-carbon economies, rare-earth elements (REEs) are crucial for modern industry, technology, and medicine. The largest known REE resource in the world is the Bayan Obo (BO) deposit in northern China. However, BO features as complicated mineral compositions and has experienced several geological events. As a reuslt, controversy remains about the BO REE genesis and enrichment mechanism, and debates are also ongoing about the controlling structure of this giant deposit. We carried out an multiscale electromagnetism study on BO mineral deposits. The multiscale study consists a microscale on samples, a small scale targeting mineral deposits and a mid scale concerning the mine field. The small and mid scale study were conducted using audio-magnetotelluric (AMT). This study revealed the controlling structure using geoelectrical characteristics. AMT data were acquired from more than 590 stations, and the petro-electromagnetism of several samples was analyzed to understand the geoelectrical features of the ore deposits and their surrounding rocks. The data were interpreted using Bostick transformation and generalized least-squares inversions. We obtained the geoelectrical structure of the BO complex down to a maximum depth of 3500 <!--> <!-->m, and we present two-dimensional imaging based on the AMT conversion results. The results show that the BO deposit developed at the transition of the high- and low-resistivity geoelectrical structure from south to north. Our AMT results indicate that the tectonic setting of the BO deposit is the transition zone between the rift edge and craton margin slope. The ore geology is presently controlled by the complex slope and the rift remnant, the ore-bearing dolostone in the profiles is Y-shaped. It goes downward from south to north and potentially features a great mineral prospect deep in the BO deposit.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S016913682400341X/pdfft?md5=675ae008e215568f2d33b41966101d37&pid=1-s2.0-S016913682400341X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142040659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genesis of Ag–polymetallic mineralization in Xiong’ershan ore-concentrated area, East Qinling, China: Constraints from in-situ pyrite geochemistry","authors":"","doi":"10.1016/j.oregeorev.2024.106205","DOIUrl":"10.1016/j.oregeorev.2024.106205","url":null,"abstract":"<div><p>The specific physicochemical processes driving compositional variations in pyrite from the porphyry–epithermal system remain elusive and challenging. The Xiong’ershan ore-concentrated area is located in the world-class East Qinling Metallogenic Belt and contains Triassic orogenic Au–Cu–Mo, Early Cretaceous porphyry–epithermal Au-Mo, and Ag-polymetallic (Au–Zn–Pb) mineralization, with pyrite (Py_T, Py_C1-C4 and Py_Ag, respectively) as the main ore mineral. The unique geological setting renders it an excellent subject for unraveling the intricate hydrothermal evolutions and mechanisms of polymetallic precipitation. The Tieluping–Shagou Ag–polymetallic (Au–Zn–Pb) mining district located in the west margin of the ore-concentrated area has long been a subject of contentious discourse regarding its genesis. This paper presents new data on the in-situ trace element and isotopic composition of Py_Ag and juxtaposes with the previous geochemistry data of Py_T and Py_C1-C4. Py_Ag exhibits the highest Ag, Pb, Zn, and Cu contents led by the Ag-bearing mineral, sphalerite, galena, and tetrahedrite inclusions. Conversely, Py_C2 and Py_C3 from the main metallogenic stage in the Early Cretaceous porphyry–epithermal Au–Mo deposits have the enrichment of Au content attributed to abundant Au-telluride inclusions. Corresponding trace element enrichment (e.g., As, Ag, Pb, Zn, Mo, Tl, and Ni), along with generally low Co and Se contents, and Sb/Bi ratios in Py_Ag suggest that the Tieluping–Shagou Ag–polymetallic (Au–Zn–Pb) mining district is epithermal mineralization. Principal component analysis (PCA) of Py_Ag further substantiates an affinity between the Ag–polymetallic (Au–Zn–Pb) mineralization and Early Cretaceous porphyry–epithermal Au–Mo mineralization. Moreover, the S–Pb isotopic ratios of Py_Ag also indicate that the ore-forming fluids of Ag–polymetallic (Au–Zn–Pb) mineralization are oxidized and originated from the Early Cretaceous magmatism. The low Se contents and Se/Ti ratios, coupled with high Tl/Se ratios in Py_Ag represent a lower temperature condition characteristic of the distal Ag–polymetallic mineralization in porphyry–epithermal system, led by the admixture of meteoric waters. The addition of increasing amounts of meteoric water leads to solubility decreases and rapid precipitation, thereby facilitating the formation of nanoparticles and inclusions of sulfides (e.g., galena, sphalerite and tetrahedrite) within low-temperature and −salinity Py_Ag. On the other hand, As-rich Py_Ag catalyzes the formation of gold solid solution in the distal Ag–polymetallic mineralization. Based on the above research, we believe that there is proximal Au–Mo mineralization in the lower part of the Ag–polymetallic mineralization nearer to the granite porphyry.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S016913682400338X/pdfft?md5=42e939b5aa82d1c4a800ecbf3f9a645d&pid=1-s2.0-S016913682400338X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142012066","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":"Resource potential evaluation of magmatic cobalt and nickel in the east Kunlun metallogenic belt, northwest of China through a geological-constrained convolutional neural network model","authors":"","doi":"10.1016/j.oregeorev.2024.106204","DOIUrl":"10.1016/j.oregeorev.2024.106204","url":null,"abstract":"<div><p>In the Kunlun orogenic belt of the East Kunlun region, several magmatic sulfide deposits of cobalt–nickel type, such as Xiarihamu and Shitoukengde, have been discovered along the Kunlun fault. The area still holds significant mineral exploration potential. This paper proposes a convolutional neural network (CNN) model based on geological constraints. When constructing the CNN model, a layer is added to restrict the magnesium-iron ratio content of mafic–ultramafic rocks in the convolutional layer, based on the characteristics of mafic–ultramafic rocks in cobalt–nickel deposits. This layer acts as a hard constraint to filter mafic–ultramafic rocks in the evidence layer, providing theoretical interpretability to the data-driven CNN <span><span>model. To</span><svg><path></path></svg></span> ensure sample balance in the prediction data and prevent overfitting during the model prediction process, a sliding window method is adopted to expand the positive samples. Predictive models are established before and after sample expansion, and ROC is used to evaluate the predictive models. Based on research into the metallogenic geological background and metallogenic model of the East Kunlun Orogenic Belt, combined with multi-source geological, geophysical, and geochemical data, a geological-constrained CNN model was used to analyze the mineralization potential of magmatic cobalt–nickel deposits in the study area. The research results show that the accuracy of the geology-constrained CNN model is 92.1 %, indicating excellent predictive performance. The results, highly consistent with known deposits, suggest that the model’s predictions can be used for resource potential assessment of magmatic cobalt–nickel deposits in the East Kunlun metallogenic belt in northwest China.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003378/pdfft?md5=715e31de316d5baf7e224019910f8f42&pid=1-s2.0-S0169136824003378-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142049367","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":"Inverse radius weighting and its python package “IRWPy”: A new topography-informed interpolation to enhance geological interpretations","authors":"","doi":"10.1016/j.oregeorev.2024.106206","DOIUrl":"10.1016/j.oregeorev.2024.106206","url":null,"abstract":"<div><p>The extent and volume of geochemical sampling are inherently constrained by numerous factors, including budgetary limitations, analytical costs, and access restrictions. These constraints result in sampling networks that vary in density and regularity, dividing regions into sampled and unsampled areas. The creation of continuous geochemical maps is essential for geochemical prospectivity, which aims to identify geochemical anomalies, distinguish between background levels and anomalies, and define mineralization patterns. Therefore, it is necessary to interpolate data from sampled areas to estimate values in unsampled regions. Although several interpolation models exist, including Inverse Distance Weighting and various kriging methods, Inverse Distance Weighting is often used in two-dimensional ground modeling because, unlike kriging methods, Inverse Distance Weighting has no smoothing effect on edges. Inverse Distance Weighting’s reliance solely on horizontal Euclidean distances between samples overlooks critical factors such as topography and the ensuing effects on dilution, transportation, and element mobility, rendering it less effective over varied elevations. This study introduces Inverse Radius Weighting, a new interpolation technique that incorporates both Euclidean and elevation fluctuations, therefore Pythagorean distance, to help with better geological interpretations. We assessed the efficacy of Inverse Radius Weighting compared to Inverse Distance Weighting across three elements with varying mobility (Arsenic − highly mobile, Copper − moderately mobile, and Barium − nearly immobile), using different numbers of neighbors and by comparing three different evaluation measures, namely R², Mean Absolute Error and Mean Absolute Percentage Error. By evaluating the spatial uncertainty of the generated maps and selecting the configurations with the least uncertainty as the final maps, our analysis reveals an improvement in correlation between interpolated and actual values with Inverse Haversine Radius Weighting. With this advancement, Inverse Haversine Radius Weighting overcomes the limitations of traditional Inverse Distance Weighting by accounting for elevation and its associated effects, thereby paving the way for more accurate and geochemically meaningful interpolation in geochemical prospectivity mapping.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003391/pdfft?md5=c8e0a6f16614c5aad1739ac8974154ce&pid=1-s2.0-S0169136824003391-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142007010","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 hydrothermal ferromanganese oxides in the Daini-Nishi-Yamato Seamount, Sea of Japan: Do they really contain critical-metal particles?","authors":"","doi":"10.1016/j.oregeorev.2024.106202","DOIUrl":"10.1016/j.oregeorev.2024.106202","url":null,"abstract":"<div><p>In submarine environments, ferromanganese (Fe–Mn) oxides are formed via various processes. Although hydrothermal Fe–Mn oxides are generally valueless as mineral resources because of their low critical metal content, they reflect temporal changes in hydrothermal activity. Metal particles, including native metals, have been observed in hydrothermal Fe–Mn oxides and associated igneous rocks that are extensively distributed in the Sea of Japan. This finding can have significant implications for metal transport in submarine hydrothermal systems. However, the existence of these metal particles requires verification because their thermodynamic coexistence with Mn oxides is challenging and has only been reported by one research team. Here, we show the growth structure and geochemistry of hydrothermal Fe–Mn oxides and volcanic rocks from the Daini-Nishi-Yamato Seamount in the Sea of Japan. The chemical and Nd–Sr isotopic compositions of the volcanic rock indicated that the Daini-Nishi-Yamato Seamount formed through magmatism after back-arc spreading in the Yamato Basin at 10–17 Ma. The hydrothermal Fe–Mn oxides consisted of Ti-rich layers that formed earlier and Ti-poor layers that formed later. The Ti-rich layers precipitated from Ti-rich hydrothermal fluids because of water–rock interactions at higher temperatures during the early stages of hydrothermal activity. During the late stages of hydrothermal activity, Ti-poor layers formed, likely because of a decrease in the temperature of the water–rock interactions and/or the depletion of Ti in the host rocks. However, unlike in previous studies, metal particles such as Ag and rare earth elements were not detected in our samples, which were impregnated with resin to prevent contamination during the polishing process. These results strongly suggest that the metal particles reported in the previous studies were contaminants.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003354/pdfft?md5=b59e78ffc9318abaf0a180147cb5a1fe&pid=1-s2.0-S0169136824003354-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142002053","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}