Economic Geology最新文献

{"title":"COUPLED Mg-Ni ISOTOPE SYSTEMATICS OF WEATHERING INTENSITY AND GARNIERITE FORMATION IN TROPICAL Ni LATERITE SYSTEMS, SULAWESI, INDONESIA","authors":"Yuri Choi,Jiwon Eom,Jung Hun Seo,Bum Han Lee,Toshihiro Yoshimura,Daisuke Araoka,Sidonie Revillon","doi":"10.5382/econgeo.5272","DOIUrl":"https://doi.org/10.5382/econgeo.5272","url":null,"abstract":"Abstract Magnesium and nickel isotopes provide insights into weathering processes and lateritic Ni enrichment; however, their coupled behavior during garnierite formation remains poorly constrained. We present Mg-Ni isotope compositions for serpentinized bedrock, garnierite, and laterite from the Morowali Ni laterite deposit, Sulawesi, Indonesia, to elucidate weathering intensity, solid-solution interaction, and mechanisms of Ni-bearing phyllosilicate precipitation. Weathering from bedrock (δ26Mg = –0.33 to –0.11‰) through saprolite (–0.20 to 0.14‰) to laterite (0.47‰) indicates preferential leaching of light Mg and retention of heavy Mg. Conversely, δ60Ni decreases from bedrock (–0.30 to 0.14‰) through saprolite (–0.78 to 0.03‰) to laterite (–1.34‰), reflecting mobilization of heavy 60Ni and adsorption of light 58Ni onto Fe oxyhydroxides. Garnierite occurs as two mineralogically and isotopically distinct groups: serpentine-like (δ26Mg = –0.10 to 0.12‰; δ60Ni = 0.98–1.46‰) and talc-like types (δ26Mg = 0.54–1.12‰; δ60Ni = 1.08–1.67‰), comparable to Ni isotope ratios in seawater (δ60Ni ≈ 1.44‰). Covariation among Mg-Ni isotopes and Ni/Mg ratios along the weathering profile suggests that both isotopes record weathering intensity and dissolution-precipitation processes. Infiltration of 60Ni-enriched fluids into the saprolite promoted garnierite precipitation and produced 60Ni-enriched ores. Petrography and Fe contents indicate that serpentine-like garnierite formed first, followed by talc-like garnierite during downward groundwater percolation. Color zoning within talc-like garnierite, from emerald rims to white cores, reflects progressive Ni and 26Mg depletion from evolving fluids. Elevated δ26Mg and depleted δ60Ni values in thick laterite horizons mark advanced weathering and may serve as geochemical indicators of underlying Ni-rich zones in Sulawesi.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"40 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 Genesis of Pollucite: Insights from the Lilypad Lakes Rare Element Pegmatite Group, Ontario, Canada","authors":"Sarah Bodeving,Anthony E. Williams-Jones,Olga Vasyukova","doi":"10.5382/econgeo.5253","DOIUrl":"https://doi.org/10.5382/econgeo.5253","url":null,"abstract":"Abstract Pollucite is the sole ore mineral of cesium, a metal deemed critical because of supply chain vulnerability. This study investigates the origin and evolution of pollucite in the Lilypad Lakes pegmatite field (Ontario, Canada), one of the few pollucite localities in North America. Textural observations and electron probe microanalyses from the Pollucite dike and Rubellite dike reveal three distinct pollucite (Pol) types: type 1 (massive Pol82), type 2 (veinlet-hosted Pol88), and type 3 (rim Pol>92). Type 1 pollucite is interpreted to have crystallized during the transition from magmatic to hydrothermal conditions, with Cs supplied by the exsolved fluid and with the Si-Al framework supplied by the coexisting melt. Subsequent separation and circulation of the fluid led to the precipitation of type 2 pollucite in veinlets crosscutting type 1 pollucite. This was accompanied by replacement of type 1 pollucite by Cs-enriched pollucite adjacent to the veinlets and by near-end-member type 3 pollucite at crystal margins, where metasomatism was most intense. The alteration of type 1 pollucite was driven by the coupled substitution Si4+ + H2O ⇌ Al3+ + (Cs,Na)+, in which the Cs/Na ratio of the fluid controlled the degree of Cs enrichment, whereas the increase in Al is charge balanced by a corresponding increase in alkalis. In the Rubellite dike, late-stage, low-temperature, Na-rich fluids induced analcimization through Cs+ ⇌ Na+ exchange. These findings challenge models that attribute pollucite formation to purely magmatic crystallization and its internal heterogeneity to subsolidus exsolution. Instead, the Lilypad Lakes data support a magmatic-hydrothermal origin and a subsolidus, fluid-driven, compositional evolution.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"18 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithocap-Hosted High-Sulfidation Epithermal Gold Mineralization at Bakan, North Sulawesi, Indonesia","authors":"Adi Maryono,Johan Arif,David R. Cooke,Saifullah Hasby,Aditya Pratama,Pete Hollings,Baskoro Rochaddi","doi":"10.5382/econgeo.5250","DOIUrl":"https://doi.org/10.5382/econgeo.5250","url":null,"abstract":"Abstract The Bakan high-sulfidation epithermal gold deposit is located approximately 150 km southwest of the provincial capital Manado, North Sulawesi, Indonesia. With only a 310-koz gold reserve at startup, the deposit has now been mined since 2013, with an annual production rate of 80 to 100 koz gold doré. The high-sulfidation epithermal deposit at Bakan can be broadly divided into four deposit variations based on alteration and mineralization styles, geometries of the orebodies, local structural controls, and hydrothermal overprints. They include the Main Ridge, Osela, Campsite, and Villa deposits. These define a volcanic landscape where the largest gold orebodies (Main Ridge and Durian) are proximal to the central magmatic-hydrothermal fluid source based on the observed porphyry-style alteration features, with other orebodies having formed in more peripheral settings. Detailed mapping, along with the application of short-wave infrared (SWIR) spectral analysis of the lithocap at the Bakan deposit, has provided vectors to the mineralized centers characterized by vuggy to pervasive quartz and also to concealed porphyry mineralization at depth. Na-rich (>1,485 nm) and mixed Na-K alunite (1,480–1,485 nm), high-temperature Fe chlorite (>2,260 nm), high-temperature advanced-argillic minerals (pyrophyllite, diaspore, topaz, and tourmaline), and high-crystallinity white mica (paragonitic muscovite ± muscovite) occur proximal to and above subeconomic porphyry copper-gold mineralization concealed at 300 m below the surface between Main Ridge and Villa. K-rich alunite (<1,480 nm) formed distal to the porphyry center and is abundant in the eight main mineralized quartz centers, as outlined by 0.1 g/t (metric tonne) gold grade shells that host 2.2 Moz gold and 14.2 Moz silver resources at Bakan. Successful exploration in the lithocap environment covering exposed targets at the surface and concealed targets at depth has extended the mine life at Bakan from three to more than 15 years.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"10 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 Carbonatitic Origin and Paragenesis of Rare Earth Element Mineralization in the Unusual Taipingzhen Deposit, Central China","authors":"Wei Zhang, Wei Terry Chen, Anthony E. Williams-Jones","doi":"10.5382/econgeo.5246","DOIUrl":"https://doi.org/10.5382/econgeo.5246","url":null,"abstract":"The Taipingzhen deposit is characterized by a rarely documented assemblage of rare earth element (REE) minerals. In addition to bastnäsite, parisite, monazite, synchysite, and allanite, which are the main REE-bearing minerals in many magmatic-hydrothermal REE deposits, it contains a large proportion of uncommon REE minerals, including fluocerite, taipingite, fluorbritholite, törnebohmite, and ferrigatelite, the genesis of which is poorly understood. The Taipingzhen orebodies are spatially and temporally associated with carbonatite dikes, and the ores have C and O isotope compositions similar to those of the carbonatites, indicating that the mineralization and carbonatites are genetically related. The order of formation of the REE minerals was controlled by the evolution of ore-forming fluids. Fluocerite was the earliest REE mineral and precipitated in response to an increase in pH that accompanied fluid phase separation. The subsequent precipitation of taipingite and fluorbritholite was triggered by further increases in pH due to the interaction of ore fluids with wall rocks. Törnebohmite and ferrigatelite began crystallizing in response to the increase in Al activity of the hydrothermal fluids that accompanied ongoing fluid-rock interaction. Bastnäsite and parisite precipitated as the fluids cooled. Monazite and allanite coprecipitated with bastnäsite and parisite due to the introduction of P, Al, and Fe as a result of fluid-rock interaction. The early formed REE minerals (e.g., fluocerite, taipingite, and fluorbritholite) were replaced extensively in the late hydrothermal stages by bastnäsite and parisite. Our study documents the relative instability of the early REE minerals, thereby explaining why they rarely survive to record the full mineralizing history of magmatic-hydrothermal REE systems elsewhere.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"42 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148415130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracing the Origin and Hydrothermal Overprint of Magnetite-Apatite Mineralization in the New Afton Cu-Au ± PGE Alkalic Porphyry Deposit: Insights from Magnetite Textures and Chemistry","authors":"Andres Felipe Gonzalez-Duran, Adam C. Simon, Robert Holder, John F.H. Thompson, Devin Wade, Catherine Ryan, Ryan Mathur","doi":"10.5382/econgeo.5243","DOIUrl":"https://doi.org/10.5382/econgeo.5243","url":null,"abstract":"Alkalic porphyry deposits are significant sources of Cu-Au ± platinum group elements (PGE), with magnetite being particularly abundant in the Triassic alkalic systems of British Columbia, Canada. The New Afton area hosts both Cu-Au ± PGE mineralization and several massive magnetite lodes, which were historically mined for iron. The origin of these magnetite orebodies and their relationship to alkalic porphyry mineralization remains unclear. This study integrates field observations and magnetite chemistry and textures to elucidate their formation. We identify two stages of magnetite mineralization: an early high-temperature (>500°C) magmatic-hydrothermal stage, characterized by ilmenite exsolution lamellae, high-Ti magnetite, and symplectitic intergrowths with ilmenite, followed by a later stage of hydrothermal reequilibration that precipitated ilmenite-free Ti-depleted magnetite. Rather than preserving its original crystallization signature, magnetite records a complex history of hydrothermal activity, including Cu-Au-PGE-bearing magmatic-hydrothermal fluid circulation and repeated, superimposed coupled dissolution-reprecipitation events. These findings align with those from other magmatic-hydrothermal ore systems such as iron oxide copper-gold and Kiruna-type iron oxide-apatite deposits, emphasizing the widespread nature of magnetite reequilibration and the need for caution when using magnetite as a petrogenetic indicator.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"14 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148415129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structurally Controlled Deposition of Gold During Inversion of Sedimentary Basin: A Case Study of Sediment-Hosted Orogenic Gold in the Gaolong Deposit, Youjiang Basin, South China Block","authors":"Yushan Zeng, Lin Yang, Qingfei Wang, Jun Deng, Artur P. Deditius, Jian-Xin Zhao, Ting Cheng, Shiyu Zhao, Shicai Huang, Di Ruan","doi":"10.5382/econgeo.5236","DOIUrl":"https://doi.org/10.5382/econgeo.5236","url":null,"abstract":"The Youjiang basin underwent late Paleozoic expansion and Triassic inversion, resulting in scattered Paleozoic isolated carbonate platforms surrounded by Triassic turbidites. The Gaolong gold deposit is representative of sediment-hosted orogenic gold deposits formed along isolated platforms in the central-southern basin, where three stages of deformation were identified. The pre-ore D1 deformation in Gaolong features a WNW-trending brachy-anticline and NNE-trending dextral strike-slip shearing within the competent carbonate platform, overthrust of the turbidites onto the carbonate platform along the lithological contacts, and WNW-trending thrusts and related asymmetric tight folds in incompetent turbidites. Kinematic analyses revealed that northeast-southwest to north northeast–south southwest regional shortening occurred. The U-Pb dating of the synkinematic calcite constrains the D1 deformation age of 240.5 ± 5.2 Ma. Syn-ore D2 deformation is associated with north-south shortening and features NE-striking sinistral and NW-striking dextral strike-slip mineralized faults that cut through the D1 structures. Gold orebodies formed in the stratigraphic-structural traps, like tight folds, thrusts, and strike-slip faults in turbidites at the less compressed and permeable eastern and western edges of the platform. Gold mineralization in those edges is mainly invisible gold in the rims of zoned pyrite and arsenopyrite in quartz veins, hydraulic breccia, and altered turbidites with ore-related silicification, sulfidation, sericitization, and minor carbonatization. The inferred stress field and published bitumen Re-Os age suggest that the D1 and D2 deformations were formed during Triassic inversion and record a change in direction of the propagation process of basin inversion. The post-ore D3-1 deformation is characterized by west-northwest–east-southeast shortening, whereas the latest post-ore D3-2 deformation represents extension. The north-northeastward basin inversion progressively propagated from the southernmost toward the northernmost of the Youjiang basin during the Middle to Late Triassic. This inversion involved horizontal crustal shortening and vertical thickening, leading to overpressure of deep fluids and triggering large-scale vertical fluid migration via regional inverted preexisting faults. These faults served as conduits, linking the deep source with shallower traps in the fold-and-thrust belt. At shallow depths, gold deposition during compression is controlled by lithological and rheological contacts along competent isolated platforms, which provide better permeability and Fe-bearing reactants that facilitate the precipitation of gold-bearing sulfide. The geochronology of progressive basin evolution and regional sediment-hosted gold mineralization reveals a coupled spatiotemporal relationship between them. Both the sedimentary facies and structural architecture preparation during basin formation and the following structural inversion and l","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"20 12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148415132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 Hydrothermal Ultrahigh-Grade Native Ag Deposit Elizabeth Hill (Western Australia): A Possible As-Depleted End Member of Five-Element Veins","authors":"Lukas Mössinger, Sebastian Staude, Benjamin F. Walter, Aratz Beranoaguirre, Gregor Markl","doi":"10.5382/econgeo.5241","DOIUrl":"https://doi.org/10.5382/econgeo.5241","url":null,"abstract":"This integrated study of the unusual, high-grade, Elizabeth Hill hydrothermal native Ag vein-type deposit in Western Australia comprises petrographic, mineral–chemical, and microthermometric data combined with hydrothermal allanite U-Pb ages. Mineralized veins are hosted by fault-controlled quartz-carbonate breccias in Archean basement rocks of the west Pilbara craton. Host rocks close to the mineralization are silicified, calcified, and chloritized. The spatially associated but older layered ultramafic-mafic, sulfide-bearing Munni Munni Complex contains magmatic chalcopyrite-pyrrhotite-pentlandite ores. These are intersected by stage I hydrothermal veins characterized by sphalerite-chalcopyrite-galena with minor pyrite, pyrrhotite, and gersdorffite, and stage II Ag mineralization hosting argentopentlandite-acanthite-native Ag. Supergene remobilization of stage I and II minerals produced multiple generations of native Ag encompassing wires, veins, and Ag-Hg amalgam (up to 35.7 wt % Hg). Chalcopyrite and acanthite allomorphs and argentopentlandite textures indicate ~330°C for stage I and 179° to 455°C for stage II. Two-phase (vapor-liquid) inclusions of stage I and early stage II, preceding Ag mineralization, are CaCl2-NaCl-H2O brines with salinities of 2.7 to 19.2 wt % NaCl equiv and Th of 98° to 166°C, which can record fluid mixing, fluid-rock interaction, or retrograde reequilibration after regional zeolite to lower greenschist facies metamorphism. Two allanite age groups (2400–2370 and 2050–1990 Ma) coincide with episodes of craton-wide metamorphism, hydrothermal activity, and orogenic-epithermal Au-vein formation. Because epithermal characteristics are absent, Elizabeth Hill may represent an As-depleted, native Ag-dominated Kongsberg-type five-element deposit. Compared to most five-element veins, however, Ni, Co, and As are rare. Repeated supergene Ag enrichment probably involved reactivation of the hosting fault system and long-term weathering.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"35 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148415136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large-Scale Structural Controls on Gold Mineralization Along the Kalgoorlie Rift From Seismic Reflection Imaging in the Neoarchean Yilgarn Craton, Western Australia","authors":"Andrew J. Calvert, Jyotindra Sapkota, Klaus Gessner, Gloria Arienti","doi":"10.5382/econgeo.5235","DOIUrl":"https://doi.org/10.5382/econgeo.5235","url":null,"abstract":"Archean granite-greenstone belts are highly prospective for structurally controlled Au, Ni, and Li mineralization, but determining the deeper structural architecture is challenging. Three regional seismic reflection surveys over the highly mineralized Neoarchean Kalgoorlie terrane in Western Australia have been reprocessed and reinterpreted using 3-D reflector orientation estimates, partial 3-D images, and geologic constraints. We divide the Kalgoorlie terrane between Ora Banda and Kambalda into northern, central, and southern domains, based on significant structural along-strike variations, including the extent to which a structural discontinuity (decollement) at 5- to 8-km depth is observed. In the northern domain, near Ora Banda, NW-striking upper crustal faulting is restricted to narrow zones between broad granite domes, and the decollement is faulted into discrete segments. In the central domain around Kalgoorlie, up to 8-km-deep structural basins of volcaniclastic rocks, separated by wedge-shaped blocks comprising mostly mafic volcanic rocks, are imaged above a largely continuous decollement. In the southern domain around Kambalda, the decollement is not observed; here, the W-dipping Boulder-Lefroy fault is part of a major fault system extending from the surface to >10-km depth, where the fault truncates against an E-dipping midcrustal shear zone that underlies the entire region. The deep structural basins, which lie below late-stage siliciclastic basins, accommodated deposition of the volcaniclastic Black Flag Group associated with mantle-derived sources for fluids and melts potentially related to Au and Li mineralization. We speculate that along-strike structural variations of the Kalgoorlie terrane, which affected both pathways and traps for Au mineralization, arose from structural inheritance and strain partitioning during rifting and subsequent crustal shortening.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"266 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148290799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tungsten Mineralization in the Eastern Alps (Austria): Implications of Scheelite Trace Element Composition for Exploration Potential Evaluation","authors":"Florian Altenberger, Joachim Krause, Kai Bachmann, Julia Weilbold, Holger Paulick, Jasper Berndt, Johann G. Raith","doi":"10.5382/econgeo.5210","DOIUrl":"https://doi.org/10.5382/econgeo.5210","url":null,"abstract":"Greenfield exploration during the 1970s to 1980s has revealed tungsten enrichment in various geologic units of the Eastern Alps. This study aims to develop assessment criteria (fingerprints) for the evaluation of regional tungsten potentials in the Eastern Alps based on mineralogical and chemical criteria from 17 of these tungsten discoveries, including the world-class Felbertal tungsten deposit. Scheelite (CaWO4) is the most common tungsten mineral in the Eastern Alps and was investigated by combined cathodoluminescence imaging, electron probe microanalysis (EPMA), and in situ laser ablation-inductively coupled plasma-mass spectrometry (LAICP-MS). This approach allows the identification of three mineralization styles in the Eastern Alps: (1) intrusion-related, (2) polymetallic (As, Sb, Au), and (3) carbonate-hosted stratabound scheelite mineralization. Our results show that the trace elements Na, Sr, Nb, Mo, and total rare earth elements (ΣREE) + Y are suitable for distinguishing scheelite from different ore-forming environments. The proposed (log[Sr/Mo] vs. log[Na/Nb]) diagram facilitates the discrimination of these mineralization styles irrespective of the metamorphic overprint and reflects chemical signatures of specific ore-forming processes. The diagram provides a clear distinction of intrusion-related magmatic-hydrothermal deposits from other styles of tungsten mineralization with less promising economic potential as well as orogenic gold deposits of metamorphogenic origin. Felbertal is clearly assigned to the intrusion-related magmatic-hydrothermal deposits and differs significantly from all the other examined scheelite occurrences in the Eastern Alps. The comparison with global scheelite data sets shows that these findings have the potential to be implemented across worldwide exploration projects.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"5 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147371518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rare Earth Element and Yttrium (REY) Hyper-Enriched Karst Bauxites of the Mercedes-Aceitillar Mining District, Sierra de Bahoruco, SW Dominican Republic","authors":"Diego Domínguez-Carretero, Thomas Aiglsperger, Cristina Villanova-de-Benavent, Lisard Torró, Núria Pujol-Solà, Xavier Llovet, Telm Bover-Arnal, Àngel Tisora, Cristina Domènech, Australia Ramírez, Jesús Rodríguez, Bernhard Dold, Joaquín A. Proenza","doi":"10.5382/econgeo.5214","DOIUrl":"https://doi.org/10.5382/econgeo.5214","url":null,"abstract":"Rare earth elements, including yttrium (REYs), are the most sought-after among the so-called critical or strategic elements for the low-carbon energy industry. In the past decade, karst bauxite deposits have been targeted as potential nonconventional sources of these elements. The karst bauxite deposits from the Mercedes-Aceitillar mining district, classified as Fe-rich bauxites and bauxites sensu stricto, contain anomalously high REY contents oscillating between 514 and 28,787 ppm (median of 1,489 ppm), making them the most REY-enriched karst bauxites globally. Most of the samples studied are enriched in light rare earth elements (La-Nd; up to 7,449 ppm) and Y (up to 14,830 ppm). However, the most REY-enriched bauxites yield particularly high middle rare earth element (Sm-Gd; up to 4,579 ppm) and heavy rare earth element (Tb-Lu; up to 6,163 ppm) contents. In addition, the studied bauxites contain significant amounts of other critical metals, such as Sc and Ga (median of 62 and 39 ppm, respectively). The mineralogy consists predominantly of Al oxyhydroxides (mostly gibbsite), with variable amounts of Fe oxyhydroxides and kaolinite. The REY mineralogy in samples with high REY contents (>3,000 ppm) consists mainly of REY-bearing phosphates (e.g., monazite, xenotime, rhabdophane, churchite) and/or carbonates (bastnäsite group). In samples with moderate REY contents (<3,000 ppm), the main REY-bearing minerals are Al oxyhydroxides, onto which the REYs are most likely adsorbed. These findings indicate that the potential extraction of REYs and other critical metals, such as Sc and Ga, in the studied bauxites from the Mercedes-Aceitillar mining district could add, on average, an ~20% surplus to the revenue obtained from Al2O3 exploitation. The unprecedented REY contents discovered in these karst bauxites from the Dominican Republic present a unique opportunity to unravel critical metal concentration mechanisms in supergene environments and to develop new geochemical models for nonconventional REY deposits.","PeriodicalId":11469,"journal":{"name":"Economic Geology","volume":"11 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147278788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}