Mineralium Deposita最新文献

{"title":"Mapping hydrothermal alteration zones with short wavelength infrared (SWIR) spectra and magnetic susceptibility at the Pulang porphyry Cu-Au deposit, Yunnan, SW China","authors":"Cheng-Biao Leng, Da-Zhao Wang, Hai-Jun Yu, Feng Tian, Xing-Chun Zhang","doi":"10.1007/s00126-023-01229-0","DOIUrl":"https://doi.org/10.1007/s00126-023-01229-0","url":null,"abstract":"<p>Delineation of hydrothermal alteration zoning is important for exploration vectoring toward mineralization centers in porphyry systems, and shortwave infrared (SWIR) spectroscopy is widely used to map hydrothermal minerals distribution for porphyry Cu exploration. However, the SWIR method cannot effectively detect anhydrous alteration minerals (e.g., K-feldspar) in the potassic zone. Magnetite can be formed by potassic alteration and destroyed by phyllic (quartz-sericite-pyrite) alteration. The relative intensity of these two alteration types can be quantified by magnetic susceptibility. Here, we integrate the SWIR and magnetic susceptibility measurements to map hydrothermal alteration zones at the Pulang porphyry Cu-Au deposit in northwestern Yunnan, one of the largest porphyry deposits in the SW China-mainland SE Asia region. White mica, chlorite, and montmorillonite + kaolinite were identified in ~ 60%, ~ 30%, and ~ 15% of the analyzed samples from the Pulang deposit, respectively. Volumetric bulk magnetic susceptibility (<i>K</i>_bulk) values are high in the potassic-altered rocks, but low in phyllic-altered rocks. Using white mica as a proxy for sericite alteration, white mica-chlorite assemblage for chlorite-sericite alteration, chlorite-epidote-actinolite assemblage for propylitic alteration, montmorillonite-kaolinite-dickite assemblage for argillic alteration, and <i>K</i>_bulk (&gt; 0.5 × 10^–3 SI) for potassic alteration, we delineate the alteration zoning at Pulang. From the causative porphyry center outward, four alteration zones are delineated (potassic → chlorite-sericite → sericite → argillic). The ore-distal propylitic alteration was developed both in the shallow and deeper levels of the hydrothermal system, resembling typical porphyry-style alteration zoning patterns. Our work shows that high <i>K</i>_bulk value is a useful vector toward Cu mineralization at Pulang, whereas illite crystallinity (SWIR-IC), white mica Al–OH spectral absorption peak, and chlorite Fe-OH spectral absorption peak are less effective. We highlight that magnetic susceptibility measurement is an effective alteration-mapping method when mineralization is developed in the potassic zone (with largely aspectral minerals such as quartz, K-feldspar, and magnetite), while SWIR scalars are more useful when mineralization is developed in the phyllic and/or propylitic zones.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"26 14","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71524385","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":"Metallogenic model of the Eocene Santa María and Antares Zn-Pb(-Ag) skarn deposits, Velardeña Mining District, Durango, Mexico","authors":"Néstor Cano, Antoni Camprubí, Eduardo González-Partida, Ana K. González-Ambrocio, Pura Alfonso, Daniel P. Miggins, Edith Fuentes-Guzmán, Edith Cienfuegos-Alvarado, Alexander Iriondo","doi":"10.1007/s00126-023-01225-4","DOIUrl":"https://doi.org/10.1007/s00126-023-01225-4","url":null,"abstract":"<p>The Santa María and Antares Zn-Pb(-Ag) skarn deposits in the Velardeña Mining District are located in central–NW Mexico. They lie 470 m apart along the contact between Oligocene felsic intrusions and Cretaceous limestones, and were developed during prograde, retrograde, post-ore (Santa María), and late stages. Firstly, the prograde stage was formed by fluids at ~ 600 °C and 15 wt% NaCl equiv., and consists of garnet + wollastonite ± clinopyroxene and biotite ± K-feldspar assemblages. Secondly, the retrograde/ore stage was formed by fluids at 300–500 °C with salinities of 20–30 wt% CaCl₂ (Santa María) and &gt; 40 wt% NaCl equiv. (Antares). It comprises assemblages of chlorite, amphibole, epidote, calcite, scapolite, quartz, sericite, adularia, fluorite, and muscovite associated with sphalerite, pyrite, galena, pyrrhotite, arsenopyrite, chalcopyrite, and Pb-Bi-Sb sulfosalts. Thirdly, the post-ore stage was formed by fluids at ~ 400 °C and 20–30 wt.% CaCl₂ and comprises poorly mineralized calcite veins. Fourthly, the late stage was formed by fluids at &lt; 300 °C and 20–30 wt.% CaCl₂ (Santa María) and ~ 15 wt% NaCl equiv. (Antares), and crystallized tetrahedrite-group minerals and pyrite + marcasite. δ¹⁸O_fluid between ~ 14‰ and 23‰ at Santa María and between ~ 12‰ and 17‰ at Antares show a less-modified magmatic affinity for mineralizing fluids at Antares; δ¹³C_fluid between 0‰ and –6‰ register recycling of sedimentary C. Moreover, sulfides with δ³⁴S_VCDT between –3‰ and 2‰ reveal a magmatic source for S. Altogether, these data suggest that, at Santa María, magmatic-derived fluids actively interacted with the wall rocks, whereas at Antares the fluid-rock interaction was milder. In both deposits, metal deposition was triggered by the cooling and neutralization of ore-bearing fluids with carbonate rocks. Our ⁴⁰Ar/³⁹Ar dates for adularia of ca. 37.5 Ma place the deposits within the Eocene–early Miocene metallogenetic epoch of central–NW Mexico, during which other world-class skarn-epithermal systems were emplaced (e.g., Concepción del Oro and Mazapil-Peñasquito).</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"63 2","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71436008","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":"Petrogenesis of Fe-Ti-P mineral deposits associated with Proterozoic anorthosite massifs in the Grenville Province: insights from oxide and apatite trace-element geochemistry at Lac à l’Orignal, Quebec, Canada","authors":"Pedro Miloski, Sarah Dare, Caroline-Emmanuelle Morisset, Joshua H. F. L. Davies, Morgann G. Perrot, Dany Savard","doi":"10.1007/s00126-023-01216-5","DOIUrl":"https://doi.org/10.1007/s00126-023-01216-5","url":null,"abstract":"<p>Proterozoic anorthosite massifs can host significant amounts of critical and strategic metals such as Ti, V, and P, associated with magmatic Fe-Ti oxides and apatite. Yet their petrogenesis is much less understood than Fe-Ti-V-P deposits hosted in layered intrusions within large igneous provinces. Several mineralized lenses of Fe-Ti-P outcrop near the border of the 1080 (±2) Ma Vanel and the 1016 (±2) Ma Mattawa Anorthosite Massifs, in the Central Grenville Province, Quebec, Canada. For example, the Lac à l’Orignal Fe-Ti-P deposit, hosted in the Vanel Anorthosite near the northern border of the Mattawa Anorthosite, comprises a lenticular structure of oxide apatite norite (OAN) with thin layers of apatite-bearing anorthosite and minor amounts of nelsonite (massive Fe-Ti oxides and apatite), indicating accumulation by density differences. Oxide settling generated the melanocratic OAN cumulates and nelsonite. Plagioclase flotation generated the leucocratic apatite-bearing anorthosite layers. The mineralization is dominated by hemo-ilmenite, accompanied by apatite and a minor amount of magnetite at the borders, whereas the core is dominated by ilmenite, magnetite, and apatite. In-situ U-Pb dating of magmatic zircon indicates that the Lac à l’Orignal deposit is a multistage intrusion with two different crystallization ages between the younger core (993 ± 13 Ma) and the older upper border (1069 ± 12 Ma) of the intrusion. These ages are similar to those of nearby anorthosite-massifs (Mattawa and Vanel Anorthosites, respectively). In-situ trace element analysis of plagioclase, apatite and oxides, by laser ablation ICP-MS, reveals subtle variations in certain trace elements (e.g., Cr, Ni, V) related to differentiation under relatively high-<i>f</i>O_<i>2</i> conditions (FMQ = +0.9 to +1.7). Calculated melt compositions from apatite indicate a similar parental magma for both the border and core that matches the composition of high-Fe-Ti-P ferrodiorite dykes at Lac à l’Original. This high-Ti-P ferrodiorite magma was probably residual after anorthosite formation. Sub-solidus inter-oxide equilibration modified the original composition of the different cumulates in the intrusion. The absence of extensive massive oxide cumulates and the presence of higher amounts of cumulus magnetite and apatite, supported by mineral chemistry, denotes a more evolved character for the Lac à l’Orignal deposit compared with other Fe-Ti-(P) deposits in the Grenville Province (e.g., Lac Tio Fe-Ti and Grader intrusion Fe-Ti-P deposits in the Havre St. Pierre Anorthosite, eastern Quebec). Petrogenetically, the Lac à l’Orignal Fe-Ti-P deposit corresponds to an evolved part of a low-Ti/Fe system in the Grenville Province in the late stages of differentiation of ferrodiorite/jotunite magmas.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"5 11","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49696199","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":"Changes in antimony isotopic composition as a tracer of hydrothermal fluid evolution at the Sb deposits in Pezinok (Slovakia)","authors":"Andreas B. Kaufmann, Marina Lazarov, Stefan Weyer, Martin Števko, Stefan Kiefer, Juraj Majzlan","doi":"10.1007/s00126-023-01222-7","DOIUrl":"https://doi.org/10.1007/s00126-023-01222-7","url":null,"abstract":"<p>In this work, we investigated in situ isotopic compositions of antimony (Sb) minerals from two substages of the ore deposits near Pezinok (Slovakia). The δ¹²³Sb values of the primary Sb minerals range from −0.4 and +0.8‰ and increase progressively along the precipitation sequence. In the substage II, the early-formed gudmundite (FeSbS) shows in all sections the lowest δ¹²³Sb values, followed by berthierite (FeSb₂S₄), stibnite (Sb₂S₃), and valentinite (Sb₂O₃) with the heaviest δ¹²³Sb values. A similar trend was observed for the substage III, from the initially-formed stibnite, followed by kermesite (Sb₂S₂O), valentinite, senarmontite (both Sb₂O₃), and schafarzikite (FeSb₂O₄). The evolution can be rationalized by a Rayleigh fractionation model with a starting δ¹²³Sb value in the fluid of +0.3‰, applying the same mineral-fluid fractionation factor to all minerals. Thus, the texturally observed order of mineralization is confirmed by diminishing trace element contents and heavier δ¹²³Sb values in successively crystallized Sb minerals. Antimony in substage III was likely supplied from the oxidative dissolution of stibnite that formed earlier during substage II. The data interpretation, although limited by the lack of reliable mineral-fluid fractionation factors, implies that Sb precipitation within each substage occurred from an episodic metal precipitation, likely associated with a similar Sb isotope fractionation between fluid and all investigated Sb minerals. Large isotopic variations, induced by precipitation from a fluid as a response to temperature decrease, may be an obstacle in deciphering the metal source in hydrothermal ore deposits. However, Sb isotopes appear to be an excellent instrument to enhance our understanding on how hydrothermal systems operate.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"6 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49696197","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":"Redox-controlled olivine-sulfide equilibration of the Shitoukengde Ni–Cu deposit in Qinghai-Tibet Plateau and its implications","authors":"Ya-Jing Mao, Xuyang Zheng, Tong Pan, Fanglin Yuan, Hua-Liang Huang, Ke-Zhang Qin","doi":"10.1007/s00126-023-01215-6","DOIUrl":"https://doi.org/10.1007/s00126-023-01215-6","url":null,"abstract":"<p> Olivine (Fo80-88) from the Shitoukengde deposit exhibits low levels of Ca, Cr, and Al (&lt; 220 ppm) and varying Ni content. The low Ca-Cr-Al contents in olivine and subsolidus temperatures (600–900 °C) indicated by olivine-spinel thermometers align with subsolidus equilibria, emphasizing substantial postcumulus modifications. Therefore, the postcumulus effect must be considered when applying olivine-spinel oxybarometers to intrusive rocks. Back-calculating the spinel Fe–Mg contents to magmatic temperature, the estimated oxidation fugacity (<i>f</i>O₂) range between FQM − 1.5 and FQM − 3.0, approximately 0.5 to 1.5 ΔFQM more reduced compared to those calculated from the raw spinel composition. Moreover, the <i>f</i>O₂ aligns with results obtained from the olivine-sulfide pair (FMQ − 3.0 to FMQ 0). The considerably reducing state and wide oxidation variation are consistent with the graphite occurrence within the reduced intervals and the systematic <i>f</i>O₂ indicated by olivine V/Sc ratios. Combined with the wide olivine Ni range (200–1500 ppm) and the restricted Ni tenor in coexisting sulfides, those findings imply that the olivine-sulfide interaction was predominantly controlled by <i>f</i>O₂. Diffusion modeling at magmatic temperatures reveals that the core-level Fe–Ni re-equilibration after crystallization requires hundreds of years. The homogeneous olivine composition suggests that re-equilibrium has been achieved in Shitoukengde. However, in fast cooling systems, olivine may record the status approaching olivine-sulfide equilibration, leading to extensive intragrain Ni variation (up to 1000 ppm). This study highlights that extreme Ni depletion in olivine from sulfide-bearing rocks is a sign of reducing conditions. Strongly Ni-rich olivine, such as those in the Kevitsa deposit, could result from interaction with high-Ni tenor sulfides at oxidizing conditions.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"5 12","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49696198","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":"Genesis of Devonian volcanic-associated Lahn-Dill-type iron ores — part I: iron mobilisation and mineralisation style","authors":"Leanne Schmitt, Thomas Kirnbauer, Thomas Angerer, Rebecca Volkmann, Vladimir Roddatis, Richard Wirth, Sabine Klein","doi":"10.1007/s00126-023-01218-3","DOIUrl":"https://doi.org/10.1007/s00126-023-01218-3","url":null,"abstract":"<p>Fe-oxide deposits of the Lahn-Dill-type in the eastern Rhenish Massif comprise haematite and quartz with minor siderite, magnetite, and calcite. The deposits are located in the hanging wall of thick volcaniclastic rock sequences and mark the Middle to Late Devonian boundary. Varying ore types with accompanying footwall rocks were sampled from two formerly important ore deposits, the Fortuna mine (Lahn syncline) and the Briloner Eisenberg mine (East Sauerland anticline), in order to elucidate the interplay of processes leading to ore formation. Deposit geology, petrography, and whole-rock geochemistry suggest that the ores formed by iron mobilisation from deeply altered footwall volcaniclastic rocks, subsequent venting of a modified H₂O-CO₂-Fe-rich and H₂S-poor fluid, and precipitation on the seafloor (sedimentary-type), or locally by metasomatic replacement of wall rocks (replacement-type). Petrographic analysis to the sub-micron scale revealed that the sedimentary-type ores most likely formed from a Fe-Si-rich gel and accompanying maturation. Early gel textures include the presence of spherules, aggregates, tubes, and filamentous stalks consisting of nanocrystalline haematite dispersed in a matrix of microcrystalline quartz. Local diagenetic Fe³⁺ reduction within the gel is indicated by siderite replacement of haematite. Replacement-type ores formed due to a two-step process including coprecipitation of (precursor) haematite and carbonates and subsequent metasomatic replacement by haematite. These ore-forming processes took place during a time when several restricted shallow marine basins in the north-eastern Rheic Ocean were influenced by extensive volcanism and associated hydrothermal fluid flux. Examples of similar volcanic-associated Fe-oxide occurrences of Silurian to Carboniferous age can be categorised as being of Lahn-Dill-type ores as well.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"6 2","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49696196","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 multiple sulfur isotope architecture of the Kambalda nickel camp, Western Australia","authors":"Sebastian Staude, Laure A.J. Martin, Matvei Aleshin, Marco L. Fiorentini, Gregor Markl","doi":"10.1007/s00126-023-01223-6","DOIUrl":"https://doi.org/10.1007/s00126-023-01223-6","url":null,"abstract":"<p>New data on the multiple sulfur isotope signature of Archean sulfides from country rocks and magmatic mineralization at the Moran deposit (Kambalda, Western Australia) were combined with previously published geochemical data to constrain the various stages of the dynamic evolution of this magmatic system, unveiling new insights into the transport mechanisms of sulfide liquids in komatiite magmas. Sulfides in the Archean magmatic and sedimentary host rocks of the komatiites display a unique mass-independent sulfur isotope signature (Δ³³S), which records a photochemical reaction of sulfur in an oxygen-poor atmosphere prior to the Great Oxidation Event.</p><p>Sedimentary rocks that are thought to be assimilated by komatiite show a distinctly positive Δ³³S signature (+ 0.9 to + 2.4‰). Early ore sulfides situated above these sedimentary rocks contain relatively few valuable metals and display an overlapping Δ³³S range (+ 0.6 to + 1.0‰). Subsequent but still early ore sulfides are situated above basalt, as the sedimentary rocks were thermo-mechanically eroded by the sulfide melt, displaying more mantle-like signatures (+ 0.2 to + 0.3‰) and valuable metal content - indistinguishable from the main ore deposit. This reflects a progressive dilution of the contaminant signature by the magmatic isotope signature of the komatiite liquid. Calculated volumes of the interaction of silicate melt and sulfide melt to explain the metal tenor of the ore and its Δ³³S signature indicate a decoupling between chemical and isotopic signatures. This can be explained by upgrading the sulfide melt with valuable metals simultaneously with the dissolution of sulfur in the komatiite melt.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"5 4","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49696204","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":"Intraplate orogenesis as a driver of multistage karst-hosted mineralization: the Imini manganese case (Atlas, Morocco)","authors":"Augustin Dekoninck, Jocelyn Barbarand, Gilles Ruffet, Yves Missenard, Nadine Mattielli, Rémi Leprêtre, Abdellah Mouttaqi, Michèle Verhaert, Omar Saddiqi, Johan Yans","doi":"10.1007/s00126-023-01212-9","DOIUrl":"https://doi.org/10.1007/s00126-023-01212-9","url":null,"abstract":"<p>The Imini mining district (southern foreland of the intraplate Atlasic belt of Morocco) hosts the largest Mn resources of North Africa, consisting of two laterally extensive bodies of high-grade pyrolusite-rich manganese ore and a third discontinuous medium-grade coronadite-rich Mn ore in a ~ 10–15-m-thick Cenomanian–Turonian dolostone unit. Until now, the origin and timing of the Mn ore have been poorly constrained. New Pb isotopic ratios show that Triassic series (basalts and ferruginous sandstone) are likely the source of the metals. ⁴⁰Ar/³⁹Ar dating of K-Mn oxides shows that the Mn-rich orebodies formed during at least three periods: late Cretaceous to late Paleocene (&gt; 58 Ma), late Eocene (ca. 36.3 Ma), and early Burdigalian to early Serravalian probably in two pulses at ca. 19–20 Ma and ca. 13 Ma. These periods coincide with three known building phases of the Atlasic relief during late Cretaceous, late Eocene, and the Early(?)-Middle Miocene. We therefore propose the Atlasic tectonics as the first-order control of the Mn mineralization. Periods with regionally high elevations modified the climate to wetter conditions that supplied meteoric water to feed temporary aquifers. Relief building created the required hydraulic head to sustain (1) fluid-rock interaction between O₂-poor acidic fluids and the Triassic series, (2) migration of the metal-rich fluid, and (3) to overpressure fluid in the Imini depositional site. The decreasing thickness of Triassic series in front of the Imini anticline forced these low-temperature (&lt; 100 °C) fluids to mix with oxygenated and alkaline ground waters in the karst system and precipitate Mn oxides. The N70°-oriented Atlasic tectonic structure controls the orientation of the Mn deposits. The late Eocene–Early/Middle Miocene uplifts generated additional supplies and/or in situ remobilization of the primary late Cretaceous medium-grade ore to form the high-grade pyrolusite-rich ore.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"1 12","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49696317","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":"Mineralogy and mineral chemistry of the ABM replacement-style volcanogenic massive sulfide deposit, Finlayson Lake district, Yukon, Canada","authors":"Nikola Denisová, Stephen J. Piercey, Markus Wälle","doi":"10.1007/s00126-023-01217-4","DOIUrl":"https://doi.org/10.1007/s00126-023-01217-4","url":null,"abstract":"<p>The ABM deposit is a bimodal-felsic, replacement-style volcanogenic massive sulfide deposit (VMS) that is hosted by back-arc affinity rocks of the Yukon–Tanana terrane in the Finlayson Lake VMS district, Yukon, Canada. Massive sulfide zones occur as stacked and stratabound lenses subparallel to the volcanic stratigraphy, surrounded by pervasive white mica and/or chlorite alteration. Remnant clasts of volcanic rocks and preserved bedding occur locally within the massive sulfide lenses and indicate that mineralization formed through subseafloor replacement of pre-existing strata. Three mineral assemblages occur at the ABM deposit: (1) a pyrite–chalcopyrite–magnetite–pyrrhotite assemblage that is associated with Cu–Bi–Se–Co-enrichment and occurs at the center of the massive sulfide lenses; (2) a pyrite–sphalerite assemblage, which occurs more commonly towards lens margins and is enriched in Zn–Pb–Ag–Au–Hg–As–Sb–Ba; and (3) a minor assemblage comprising chalcopyrite–pyrrhotite–pyrite stringers associated with pervasive chlorite alteration, which occurs mostly at the sulfide lens margins. Petrographic observations of preserved primary, zone refining, and metamorphic textures in combination with in situ geochemistry show that the pyrite–sphalerite assemblage formed at lower temperatures (&lt; 270 °C) than the other two mineral assemblages (~ 270–350 °C), and that mineral chemistry in all mineral assemblages was affected by greenschist facies metamorphism, although the effects are limited to recrystallization, small-scale remobilization (&lt; 1 m) and trace element redistribution.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"2 7","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49696310","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 origin of fluorite-barite mineralization at the interface between the Paris Basin and its Variscan basement: insights from fluid inclusion chemistry and isotopic (O, H, Cl) composition","authors":"Louise Lenoir, Thomas Blaise, Diana Chourio-Camacho, Antonin Richard, Alexandre Tarantola, Pierre Agrinier, Thomas Rigaudier, Gaël Monvoisin, Gérard Bardoux, Benjamin Brigaud, Jocelyn Barbarand","doi":"10.1007/s00126-023-01219-2","DOIUrl":"https://doi.org/10.1007/s00126-023-01219-2","url":null,"abstract":"<p>We provide new constraints for the fluid flow system at the origin of two F-Ba deposits located at the unconformity between the south of the Paris Basin and the northern edge of the French Massif Central. We used microthermometry and bulk crush-leach analyses to determine isotope ratios of mineralizing fluids (δ¹⁸O, δD, δ³⁷Cl), together with cation and anion composition of fluid inclusions hosted by fluorite. Chlorinity and Cl/Br molar ratios (212–521) indicate the involvement of a brine, whose origin likely corresponds to Triassic evaporated seawater compatible with supratidal dolomitic facies preserved nearby. Microthermometry reveals high Ca/Na ratios, suggesting that the brine composition evolved from hydrothermal alteration of the Variscan basement and partial dissolution and replacement of the host sedimentary rocks. δ³⁷Cl values are lower than the expected value of evaporated seawater, suggesting Cl isotope fractionation by ion filtration in clay-rich horizons. Fluorite crystallized at minimum temperatures of 70 to 110 °C, 10–40 °C warmer than the host Triassic sedimentary rocks. Ascending brines were expelled during the Early Cretaceous and experienced a drop in pressure and temperature, together with possible mixing with the SO₄-rich pore water of the sedimentary rocks, causing precipitation of silica, followed by fluorite and barite, forming a stratabound deposit similar to those found in many areas in Western Europe.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"2 8","pages":""},"PeriodicalIF":4.8,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49696309","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}