Subjects -> MINES AND MINING INDUSTRY (Total: 82 journals)
Showing 1 - 42 of 42 Journals sorted by number of followers
Stainless Steel World     Full-text available via subscription   (Followers: 18)
Journal of Applied Geophysics     Hybrid Journal   (Followers: 16)
Journal of Metamorphic Geology     Hybrid Journal   (Followers: 15)
International Journal of Hospitality & Tourism Administration     Hybrid Journal   (Followers: 14)
European Journal of Mineralogy     Hybrid Journal   (Followers: 12)
Journal of Geology and Mining Research     Open Access   (Followers: 11)
Contributions to Mineralogy and Petrology     Hybrid Journal   (Followers: 11)
Mineral Processing and Extractive Metallurgy : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 11)
Transactions of Nonferrous Metals Society of China     Hybrid Journal   (Followers: 10)
Journal of Human Resources in Hospitality & Tourism     Hybrid Journal   (Followers: 9)
Clay Minerals     Hybrid Journal   (Followers: 9)
Minerals Engineering     Hybrid Journal   (Followers: 9)
Lithos     Hybrid Journal   (Followers: 9)
International Journal of Minerals, Metallurgy, and Materials     Hybrid Journal   (Followers: 9)
Natural Resources Research     Hybrid Journal   (Followers: 8)
Geotechnical and Geological Engineering     Hybrid Journal   (Followers: 8)
Rock Mechanics and Rock Engineering     Hybrid Journal   (Followers: 7)
International Journal of Rock Mechanics and Mining Sciences     Hybrid Journal   (Followers: 6)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
International Journal of Mining Engineering and Mineral Processing     Open Access   (Followers: 5)
Journal of Quality Assurance in Hospitality & Tourism     Hybrid Journal   (Followers: 5)
Mine Water and the Environment     Hybrid Journal   (Followers: 5)
International Journal of Mining and Mineral Engineering     Hybrid Journal   (Followers: 5)
Journal of the Southern African Institute of Mining and Metallurgy     Open Access   (Followers: 5)
Mining Engineering     Full-text available via subscription   (Followers: 5)
Resources Policy     Hybrid Journal   (Followers: 4)
International Journal of Mining Science and Technology     Open Access   (Followers: 4)
Reviews in Mineralogy and Geochemistry     Hybrid Journal   (Followers: 4)
Mineral Processing and Extractive Metallurgy Review     Hybrid Journal   (Followers: 4)
Applied Earth Science : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 4)
International Journal of Mining, Reclamation and Environment     Hybrid Journal   (Followers: 4)
International Journal of Coal Geology     Hybrid Journal   (Followers: 4)
Physics and Chemistry of Minerals     Hybrid Journal   (Followers: 4)
Journal of Convention & Event Tourism     Hybrid Journal   (Followers: 4)
Mineralium Deposita     Hybrid Journal   (Followers: 4)
Lithology and Mineral Resources     Hybrid Journal   (Followers: 3)
Journal of Sustainable Mining     Open Access   (Followers: 3)
International Journal of Coal Science & Technology     Open Access   (Followers: 3)
Mining Journal     Full-text available via subscription   (Followers: 3)
Ghana Mining Journal     Full-text available via subscription   (Followers: 3)
Geology of Ore Deposits     Hybrid Journal   (Followers: 3)
Rocks & Minerals     Hybrid Journal   (Followers: 3)
Environmental Geochemistry and Health     Hybrid Journal   (Followers: 2)
Journal of Mining Science     Hybrid Journal   (Followers: 2)
Geomaterials     Open Access   (Followers: 2)
Mineralogia     Open Access   (Followers: 2)
BHM Berg- und Hüttenmännische Monatshefte     Hybrid Journal   (Followers: 2)
Mining Technology : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 2)
Extractive Industries and Society     Hybrid Journal   (Followers: 2)
International Journal of Coal Preparation and Utilization     Hybrid Journal   (Followers: 2)
Mineralogy and Petrology     Hybrid Journal   (Followers: 2)
Mining Report     Hybrid Journal   (Followers: 2)
Neues Jahrbuch für Mineralogie - Abhandlungen     Full-text available via subscription   (Followers: 2)
Archives of Mining Sciences     Open Access   (Followers: 2)
Journal of Materials Research and Technology     Open Access   (Followers: 2)
Gems & Gemology     Full-text available via subscription   (Followers: 1)
Journal of Analytical and Numerical Methods in Mining Engineering     Open Access   (Followers: 1)
Rangeland Journal     Hybrid Journal   (Followers: 1)
Revista del Instituto de Investigación de la Facultad de Ingeniería Geológica, Minera, Metalurgica y Geográfica     Open Access   (Followers: 1)
Journal of Central South University     Hybrid Journal   (Followers: 1)
Mineralogical Magazine     Hybrid Journal   (Followers: 1)
CIM Journal     Hybrid Journal  
Natural Resources & Engineering     Hybrid Journal  
Mining, Metallurgy & Exploration     Hybrid Journal  
Podzemni Radovi     Open Access  
Rudarsko-geološko-naftni Zbornik     Open Access  
Journal of Mining Institute     Open Access  
International Journal of Mining and Geo-Engineering     Open Access  
Journal of China Coal Society     Open Access  
Réalités industrielles     Full-text available via subscription  
Mineral Economics     Hybrid Journal  
Minerals     Open Access  
Gold Bulletin     Hybrid Journal  
Minerals & Energy - Raw Materials Report     Hybrid Journal  
Similar Journals
Journal Cover
Mineralium Deposita
Journal Prestige (SJR): 1.601
Citation Impact (citeScore): 4
Number of Followers: 4  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1432-1866 - ISSN (Online) 0026-4598
Published by Springer-Verlag Homepage  [2469 journals]
  • Geology of the Altamira and Las Luces deposits, Coastal Cordillera,
           northern Chile: implications for the origin of stratabound Cu–(Ag)
           deposits

    • Free pre-print version: Loading...

      Abstract: Abstract Stratabound Cu–(Ag) deposits in the Coastal Cordillera of northern Chile were emplaced under an extensional setting during the Late Jurassic and Early Cretaceous. Las Luces and Altamira are two stratabound Cu–(Ag) deposits located approximately at the same latitude (~ 25°45′S), but the former is hosted by Jurassic volcanic and volcaniclastic rocks, and the latter by Cretaceous volcano-sedimentary sequences. Both deposits show similar hydrothermal alteration types with albitization and hematite–chlorite superimposed on low-grade regional metamorphism. Sulfide mineralization is represented mainly by pyrite, chalcopyrite, and a bornite– “chalcocite” assemblage. Chalcopyrite is relatively minor and can replace early pyrite. In addition, framboidal pyrite of possible diagenetic origin was observed in Altamira. Copper mineralization is dominated by a bornite– “chalcocite” assemblage; however, electron probe analyses show that “chalcocite” has a composition ranging from geerite to djurleite. The typical mymekitic-like exsolution texture observed in the bornite–Cu sulfides assemblage is interpreted as caused by sub-solidus re-equilibration on cooling of the bornite–digenite solid solution. Silver, the main by-product in these deposits, is probably incorporated in solid solution in Cu sulfides and bornite, although Ag–sulfide microparticles were occasionally observed within sulfides in Altamira. Copper sulfides of the geerite–djurleite series can contain high amounts of Ag, ranging between 202 and 789 ppm, whereas in bornite from Las Luces Ag can reach up to 270 ppm. The presence of low-temperature (~ 100 °C) hydrothermal Cu sulfides is consistent with formation temperatures of < 300 °C, based on previous fluid inclusion studies. Bulk stable isotope data shows that sulfur in these deposits have different sources. In Las Luces δ34S values for bornite and pyrite (− 2.5 to + 2.9‰) indicate a magmatic source, whereas in Altamira the negative values for “chalcocite” (δ34S: − 38.7 to − 10.7‰) are interpreted as sulfur derived by bacterial reduction of marine sulfate. The Las Luces and Altamira deposits were possibly formed by high water/rock ratios where basin-derived fluids leached metals from the volcanic/volcano-sedimentary host rocks. However, extensive leaching of the volcanic host rocks necessary to extract the Cu contained in silicate minerals is not consistent with the relatively small volume of hydrothermal alteration associated with these deposits, suggesting an additional magmatic contribution. In the revised genetic model, variable contributions of a magmatic and non-magmatic source are needed to form these stratabound Cu–(Ag) deposits.
      PubDate: 2022-08-08
       
  • Timing of magmatic-hydrothermal activity in the Variscan Orogenic Belt:
           LA-ICP-MS U–Pb geochronology of skarn-related garnet from the
           Schwarzenberg District, Erzgebirge

    • Free pre-print version: Loading...

      Abstract: Abstract Here, we present in situ U–Pb laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) ages of andradite-grossular garnet from four magmatic-hydrothermal polymetallic skarn prospects in the Schwarzenberg District, Erzgebirge (Germany), located in the internal zone of the Variscan Orogenic Belt. Within the geochronological framework of igneous rocks and hydrothermal mineralization in the Erzgebirge, the obtained garnet ages define three distinct episodes of Variscan skarn formation: (I) early late-collisional mineralization (338–331 Ma) recording the onset of magmatic-hydrothermal fluid flow shortly after the peak metamorphic event, (II) late-collisional mineralization (~ 327–310 Ma) related to the emplacement of large peraluminous granites following large-scale extension caused by orogenic collapse and (III) post-collisional mineralization (~ 310–295 Ma) contemporaneous with widespread volcanism associated with Permian crustal reorganization. Our results demonstrate that the formation of skarns in the Schwarzenberg District occurred episodically in all sub-stages of the Variscan orogenic cycle over a time range of at least 40 Ma. This observation is consistent with the age range of available geochronological data related to magmatic-hydrothermal ore deposits from other internal zones of the Variscan Orogenic Belt in central and western Europe. In analogy to the time–space relationship of major porphyry-Cu belts in South America, the congruent magmatic-hydrothermal evolution in the internal zones and the distinctly later (by ~ 30 Ma) occurrence of magmatic-hydrothermal ore deposits in the external zones of the Variscan Orogenic Belt may be interpreted as a function of their tectonic position relative to the Variscan collisional front.
      PubDate: 2022-08-01
       
  • Precise ages of gold mineralization and pre-gold hydrothermal activity in
           the Baiyun gold deposit, northeastern China: in situ U–Pb dating of
           hydrothermal xenotime and rutile

    • Free pre-print version: Loading...

      Abstract: Abstract Timing of the major Baiyun gold deposit (~ 70 t Au) in the northeastern North China Craton is controversial. A textural and geochronological study of high-grade gold ores identifies three generations of xenotime (Xtm-1, Xtm-2 and Xtm-3), even in single grains. The oldest Xtm-1, in grain cores, is of metamorphic origin, with very high U and U/Th ratios, and hump-shaped, HREE-enriched patterns with maximum normalized values at Yb and large negative Eu anomalies. It is dated at 1856 ± 6 Ma, consistent with its crystallization during regional metamorphism related to cratonization. In contrast, 244 ± 2 Ma Xtm-2 overgrowths are of hydrothermal origin, having low U and U/Th ratios and hump-shaped, MREE-enriched patterns with maximum normalized values at Ho and negligible Eu anomalies. Xtm-2 records a previously unrecognized Middle Triassic hydrothermal episode. Xtm-3, in equilibrium with native gold-hosting pyrite and rutile, is also hydrothermal. The Xtm-3 domains have similar U, U/Th ratios, and MREE-enriched patterns to Xtm-2, but a younger crystallization age of 231 ± 1 Ma. Associated rutile grains that show close textural associations with auriferous pyrite and native gold have an in situ SIMS U–Pb an intercept age of 229 ± 4 Ma, consistent with that of Xtm-3. Collectively, these reliable ages indicate that gold mineralization at Baiyun occurred at ca. 230 Ma, predating the emplacement of granite intrusions by more than 3 million years. Both the Middle Triassic hydrothermal event (~244 Ma) and the Late Triassic gold mineralization event (~230 Ma) lie within the temporal window of collisional tectonics in the host orogen. In combination, the new geochronology and fluid-inclusion and geological data support Bayun’s classification as an orogenic gold deposit.
      PubDate: 2022-08-01
       
  • Mineral-scale variation in the trace metal and sulfur isotope composition
           of pyrite: implications for metal and sulfur sources in mafic VMS deposits
           

    • Free pre-print version: Loading...

      Abstract: Abstract The link between metal enrichment and the addition of a magmatic volatile phase in volcanogenic massive sulfide deposits and actively forming seafloor massive sulfide deposits remains poorly characterized. This is especially true when considering how metal, sulfur and fluid flux change with time. In this study, we combine in situ sulfur isotope (δ34S; n = 31) measurements with trace metal chemistry of pyrite (n = 143) from the Mala VMS deposit, Troodos, Cyprus. The aim of our study is to assess the links between volatile influx and metal enrichment and establish how, or indeed if, this is preserved at the scale of individual mineral grains. We classify pyrite based on texture into colloform, granular, disseminated and massive varieties. The trace metal content of different pyrite textures is highly variable and relates to fluid temperature and secondary reworking that are influenced by the location of the sample within the mound. The sulfur isotope composition of pyrite at Mala ranges from − 17.1 to 7.5‰ (n = 31), with a range of − 10.9 to 2.5‰ within a single pyrite crystal. This variation is attributed to changes in the relative proportion of sulfur sourced from (i) SO2 disproportionation, (ii) thermochemical sulfate reduction, (iii) the leaching of igneous sulfur/sulfide and (iv) bacterial sulfate reduction. Our data shows that there is no correlation between δ34S values and the concentration of volatile elements (Te, Se) and Au in pyrite at Mala indicating that remobilization of trace metals occurred within the mound.
      PubDate: 2022-08-01
       
  • Biotite composition as a tracer of fluid evolution and mineralization
           center: a case study at the Qulong porphyry Cu-Mo deposit, Tibet

    • Free pre-print version: Loading...

      Abstract: Abstract Porphyry Cu-Mo deposits are magmatic-hydrothermal deposits in which sulfide and oxide minerals precipitate from aqueous solutions. However, many questions remain about the composition and evolution of the magmatic-hydrothermal fluids responsible for mineralization. In response to this knowledge gap at the Qulong porphyry Cu-Mo deposit, Tibet, we present a comprehensive major and trace element dataset for biotite (including halogens) from Qulong to elucidate magmatic-hydrothermal fluid compositions and fluid evolution. Based on genesis and occurrence, biotite is divided into primary (igneous), re-equilibrated (igneous modified by hydrothermal fluids), and secondary (hydrothermal) types. All studied biotite grains are Mg-rich, and XMg values (0.59–0.90) increased during fluid evolution, perhaps controlled by high oxygen fugacity (fO2) and sulfur fugacity (fS2) in the magmatic-hydrothermal fluids. The IV(F) and IV(Cl) values and halogen fugacity of biotite indicate that Cl-rich fluids were dominant during early magmatic-hydrothermal evolution, while later fluids were enriched in F. This is consistent with early Cu and late Mo enrichment in the Qulong deposit. We propose a fluid evolution model based on in situ major and trace element data and cross-cutting relationships between the intrusions and the veins. Iron, Ti, Co, Ni, Zn, and Cl contents decreased, while Mg, Si, Al, Sn, Ge, and F contents increased during the evolution of the magmatic-hydrothermal fluid. Importantly, the increase in Fe, Ti, Co, Zn, and Cl and decrease in Mg, Ge, and F contents in hydrothermal biotite as the core of the deposit is approached (extending to ~ 2.5 km depth) may prove to be an important indicator of high-grade mineralized zones. Finally, this study shows that systematic spatial variations in hydrothermal biotite chemistry can potentially be used as a prospecting tool for porphyry deposits worldwide.
      PubDate: 2022-08-01
       
  • Timing and tectonic setting of tin mineralization in southern Myanmar:
           constraints from cassiterite and wolframite U–Pb ages

    • Free pre-print version: Loading...

      Abstract: Abstract The southern Myanmar tin ore district is an important part of the well-known Southeast Asia tin belt (SATB), and hosts numerous economically important primary tin-tungsten ore deposits. However, the timing of formation of these deposits is unclear due to the scarcity of robust age data. The tectonic setting of tin mineralization in this area also needs to be further constrained. Most of the primary tin-tungsten ore deposits in southern Myanmar are typical hydrothermal quartz vein–type, with cassiterite and wolframite as the main ore minerals. Here, we present in situ U–Pb ages of cassiterite and wolframite from nine granite-related hydrothermal Sn–W deposits in southern Myanmar. Cassiterite samples from the Hermyingyi, Thitkhatoe, Thaling Taung, Kalonta, Taungphila, Pagaye, Bawapin, Kanbauk, and Letha Taung deposits yield common lead-corrected weighted mean 206Pb/238U ages of 61.6 ± 0.8 Ma, 61.9 ± 0.6 Ma, 60.4 ± 0.9 Ma, 63.0 ± 0.6 Ma, 62.9 ± 0.6 Ma, 69.5 ± 0.5 Ma, 63.6 ± 0.6 Ma, 61.3 ± 0.6 Ma, and 84.9 ± 0.5 Ma, respectively. Wolframite samples collected from these deposits also yield consistent ages with the cassiterite samples. These ages, combined with available tin mineralization ages from other deposits in the western part of the SATB, define three epochs of Sn metallogeny related to three contrasting geodynamic settings: (1) Early Cretaceous (~ 125–110 Ma) mineralization is related to post-collision slab break-off after collision between the West Burma terrane and the Sibumasu-Tengchong terrane; (2) Late Cretaceous to Paleocene (~ 90–60 Ma) mineralization developed in an Andean-type accretionary setting during subduction of the Neo-Tethys oceanic lithosphere; (3) Early Eocene (~ 50–40 Ma) mineralization may have formed in a post-collision setting after the India-Asia collision.
      PubDate: 2022-08-01
       
  • Quantifying the nature of ore-forming fluids in the Dalucao
           carbonatite-related REE deposit, Southwest China: implication for the
           transport and deposition of REEs

    • Free pre-print version: Loading...

      Abstract: Abstract Carbonatite-related rare earth element (REE) deposits are major hosts of REE resources. REE mineralization in these deposits is generally associated with hydrothermal systems at late stages of carbonatite evolution, but the nature of ore-forming fluids and their role in concentrating REEs are not well understood. In this study, we quantified the nature of ore-forming fluids by conducting a detailed investigation on the fluid inclusions of the Dalucao carbonatite–related REE deposit, Southwest China. Based on the phases present at room temperature, three types of fluid inclusions, namely, high-density, CO2-rich inclusions, solid-bearing brine inclusions, and aqueous liquid inclusions, have been distinguished in the deposit. High-resolution Raman mapping reveals that the daughter minerals in the earliest brine inclusions are dominantly composed of sulfate (average mass proportion of 92.3%) with minor chloride (3.1%), carbonate (4.4%), and silicate (0.2%). In addition, a Raman peak of SO42– has been detected in the liquid phase of the aqueous inclusions. These new results suggest that the early, high-temperature ore-forming fluids are unique for containing extremely high concentrations of sulfate. Such sulfate-rich fluids are confirmed to be responsible for transporting appreciable amounts of REEs in the forms of REE-sulfate complexes. We further propose that deposition of REE minerals was mainly triggered by decreasing temperatures, which, as a result, reduced the solubility of sulfate in the fluids. Our new findings highlight the fact that sulfate-rich fluids tend to be more common in carbonatite-related REE deposits and play key roles in REE mineralization.
      PubDate: 2022-08-01
       
  • Low-temperature hydrothermal Pt mineralization in uvarovite-bearing
           ophiolitic chromitites from the Dominican Republic

    • Free pre-print version: Loading...

      Abstract: Abstract Platinum-group elements (PGEs) occur in ophiolitic chromitite in the Dominican Republic as platinum-group minerals (PGMs) in spatial association with hydrothermal uvarovite and chromian clinochlore. Bulk-rock total PGE content in a single analyzed chromitite sample is of 6.54 g/t. Three main PGM types are distinguished: euhedral magmatic laurite completely encased in chromite, subhedral to euhedral Ru-Os-Fe-(Ir) compounds partially encased in chromite, and anhedral Pt-Fe–Ni-rich grains exclusively embedded in uvarovite or chromian clinochlore. The Ru-Os-Fe-(Ir) compounds are interpreted as magmatic Ru-Os sulfides that experienced desulfurization during hydrothermal alteration of the chromitites, whereas the Pt-Fe–Ni-rich grains are hydrothermal in origin. We propose a model in which the Pt-Fe–Ni-rich PGMs formed via the accumulation of nanoparticles directly precipitated from the hydrothermal fluids. An estimation of the temperature of crystallization of uvarovite and chromian clinochlore suggests hydrothermal alteration of the chromitite within the thermal range of 150–350 °C. Thermodynamic modeling shows that, within this range of temperature, Pt could be mobilized as aqueous bisulfide complexes (HS−) by S-poor, highly reducing hydrothermal fluids originated during serpentinization of the host chromitite rock. The crystallization of Ni sulfides in the chromitite would drop the S concentration of the fluid, causing the precipitation of Pt as native element. Ultimately, this process contributes to constrain the conditions for the genesis of hydrothermal PGE mineralizations in ophiolitic chromitites.
      PubDate: 2022-08-01
       
  • Constraints on the structural setting, relative timing, and geochemistry
           of the Fimiston, Hidden Secret, and Oroya gold-telluride lode types,
           Kalgoorlie gold camp, Western Australia

    • Free pre-print version: Loading...

      Abstract: Abstract Late-stage metamorphic (ca. 2.64 Ga) and punctuated magmatic-hydrothermal mineralization models (2.67–2.64 Ga) are proposed for gold mineralization in the Kalgoorlie gold camp (~ 2300 t Au; Archean Yilgarn craton, Western Australia). We present structural, whole-rock geochemical, pyrite trace element, and multiple sulfur isotope data to evaluate these models. Both the Fimiston and Hidden Secret lodes were emplaced in ca. 2675 Ma D2b transtensional settings as releasing bends developed along the Golden Mile and Towns faults, respectively, and are related to the ingress of a H2O-CO2-Au-Te-As-S-K-Rb-Ba fluid concomitant with the intrusion of andesitic dikes. In the Hidden Secret orebody, this magmatic-hydrothermal fluid evolved from an early, As-enriched, greenstone-buffered fluid during the formation of disseminated pyrite mineralization (δ34Spyrite = 3.42 to 3.85‰; Δ33Spyrite = 0.25 to 0.43‰) to an Ag-Cu-Pb-Sb-Te-Tl-V-Zn–enriched fluid during the development of banded quartz-carbonate-sericite-pyrite veins (δ34Spyrite =  - 10.74 to - 0.17‰; Δ33Spyrite = 0.06 to 0.19‰). Oroya gold-telluride lode mineralization formed during later, ca. 2660 Ma D2c transpression from a V-S–Au-Ag-Hg-Te–enriched magmatic-hydrothermal fluid represented by δ34Spyrite = - 11.56‰ to - 4.96 and Δ33Spyrite = 0.08 to 0.17‰. The Fimiston/Hidden Secret and Oroya mineralization events record oxidized magmatic-hydrothermal fluids represented by δ34Spyrite ≤ 0‰ and Δ33Spyrite ~ 0.0 to 0.2‰. These oxidized magmatic-hydrothermal fluids interacted with surrounding wall rock, which lowered fluid fO2 and buffered δ34Spyrite/Δ33Spyrite values to δ34Spyrite =  ~ 1 to 5‰/Δ33Spyrite =  ~ 0.2 to 0.7‰ in greenstone rock environments and to δ34Spyrite =  ~ 1 to 5‰/Δ33Spyrite =  ~  ≤ 0.3‰ and ≥ 0.7‰ in black shale environments. Anomalous Δ33S values in ore-stage sulfides formed locally due to the incorporation of sulfur during fluid-wall rock interaction. The early, magmatic-hydrothermal Fimiston/Hidden Secret and Oroya gold-telluride lodes differ texturally, geochemically, and mineralogically from the D3 Mt. Charlotte stockwork veins, which formed subsequent to ca. 2650 Ma and better adhere to a late-stage metamorphic devolatilization model.
      PubDate: 2022-08-01
       
  • Multi-stage sulfide evolution of the Moran Ni sulfide ore, Kambalda,
           Western Australia: insights into the dynamics of ore forming processes of
           komatiite-hosted deposits

    • Free pre-print version: Loading...

      Abstract: Abstract The Moran komatiite-hosted Ni sulfide deposit at Kambalda (Australia) is one of the better preserved orebodies at Kambalda. Its geochemical signature is used to investigate the evolution of the sulfide mineralization. The orebody has several parts, including a flanking segment where massive sulfides formed relatively early and a central portion in a 40-m-deep erosional embayment representing a later generation of massive and net-textured sulfides. Basal massive sulfides within the deep embayment vary systematically in their chalcophile element contents (Ni, PGE, Au, Te, As, Bi). Elements compatible in monosulfide solid solution (MSS) exhibit the highest concentration at the edge of the orebody (up to 4.3 ppm Ir + Os + Ru + Rh), whereas incompatible elements are most concentrated in the centre (up to 11.2 ppm Pt + Pd + Au). This difference in element distributions is explained by fractional crystallization of sulfide melt from the edge towards the centre. To explain the vertical movement of the residual fractionated melt, a new model of sulfide crystallization is proposed. A low-viscosity boundary layer containing incompatible elements is formed between MSS and sulfide melt. This melt propagates with the crystallization front towards the centre of the sulfide melt pool. Trace element variations in pentlandite (e.g. Co) and composite Co- and Bi-bearing arsenide-telluride grains suggest that during the final stages of crystallization, an immiscible Co-As-Te-Bi melt is formed.
      PubDate: 2022-08-01
       
  • Formation of Sn-rich granitic magma: a case study of the highly evolved
           Kafang granite in the Gejiu tin polymetallic ore district, South China

    • Free pre-print version: Loading...

      Abstract: Abstract The Gejiu ore district (~ 3.2 Mt Sn) is located in eastern Yunnan Province, southwest China, and is one of the largest Sn polymetallic ore districts in the world. Athough it has been widely studied, the petrogenesis of ore-related granites is still unclear. In this paper, we present petrological, geochemical, and geochronological data on the granites associated with the Kafang Cu–Sn deposit in the Gejiu ore district (65 Mt Cu ore at a grade of 1.2% and 32 Mt Sn ore at a grade of 0.6%). We use these data to constrain the source, evolution, oxygen fugacity, and tectonic setting of the granitic magmatism. Zircon U–Pb dating yielded an age of 82.8 ± 0.6 Ma for the Kafang granite. The high zircon δ18O values (7.45–9.74‰; mean = 8.80‰) and narrow range of εNd(t) values (–9.0 to –7.7) of the Kafang granite indicate a highly evolved S-type granite derived by partial melting of metamorphic basement rocks of the Jiangnan orogenic belt. Rayleigh fractional crystallization modeling, along with the increase in Hf and Sn contents and decrease in Eu/Eu* values of zircons, record extensive fractional crystallization, and Sn enrichment during magmatic evolution. The Kafang granite was relatively reduced, as evidenced by low zircon Ce/Ce* (10.0–366; mean = 171), (Ce/Nd)N (0.76–8.32; mean = 4.41), △FMQ (–2.5 to 1.2) values, and Fe3+-depleted biotite compositions (Fe3+/(Fe3+  + Fe2+) = 0–0.10), which were favorable for Sn mineralization but not for Cu mineralization. Copper in the Kafang deposit may not have been derived from the granite. Our results suggest that biotite and zircon geochemical compositions, particularly biotite Mg# and A/CNK values and zircon Hf contents, Eu anomalies, and Ce/Ce* and (Ce/Nd)N ratios, are robust tracers of different types of magmatic-hydrothermal ore deposits (i.e., Cu, Mo, W, and Sn). Late Cretaceous magmatism in the Gejiu region and other areas along the southern margin of South China formed an E–W-trending igneous belt that was likely related to northward subduction of the Neo-Tethyan plate rather than northwestward subduction of the Paleo-Pacific plate.
      PubDate: 2022-07-15
       
  • U–Pb vein xenotime geochronology constraints on timing and longevity of
           orogenic gold mineralization in the Malartic-Val-d’Or Camp, Abitibi
           Subprovince, Canada

    • Free pre-print version: Loading...

      Abstract: Abstract Despite a well-developed structural framework, orogenic gold deposits from the Malartic-Val-d’Or Camp (MVC) report ages that span nearly 345 million years (~ 2705–2360 Ma), significantly post-dating the tectono-metamorphic history of the Abitibi-Wawa Orogeny, and are in conflict with the structural setting along the retrograde path of the orogenic cycle. Gold in the MVC is commonly associated with three events that form pre- and syn-/late-regional penetrative fabric (S2), developed during major N-S shortening (D2, ~ 2669–2643 Ma): (1) pre-D2 quartz-carbonate veins; (2) deformed quartz-carbonate stockworks, entrained in S2; (3) laminated brittle-ductile quartz-tourmaline-carbonate reverse-shear and tension veins, sub-parallel to S2, which contain the bulk of the gold. Here, we present in situ U–Pb geochronological and rare earth element (REE) data from 85 xenotime grains, hosted by quartz-carbonate veins (Kiena S50) and quartz-tourmaline-carbonate veins (Goldex, Triangle, Plug #4, Beaufor, Pascalis Gold Trend, and Akasaba West). Xenotime in textural equilibrium with Au-hosting pyrite of pre-D2 veins yields a subtle negative Eu anomaly and elevated medium-REE contents, and records an auriferous hydrothermal event at 2686 ± 15 Ma (n = 19; 11 grains; MSWD = 2.8), consistent with cross-cutting relationships with dated intrusions. Late-D2 veins record two subsequent hydrothermal events, based on texture and chemistry of xenotime. Xenotime in textural equilibrium with gold-bearing pyrite contains elevated medium-REE values (Nd>1000 ppm; Sm>2490 ppm) and constrains the timing of vein emplacement to 2643 ± 3 Ma (n = 92; 44 grains; MSWD = 1.2), dating the main phase of quartz-tourmaline-carbonate vein formation and major gold precipitation. Xenotime in textural disequilibrium with auriferous sulfides, located at dissolved sulfide grain boundaries and in sulfide fractures, contains lower medium-REE values (Nd<1000 ppm; Sm<2490 ppm), and yields an age of 2607 ± 5 Ma (n = 63; 30 grains; MSWD = 1.9), indicating a second period of gold mineralization. Our data imply that district-scale gold mineralization in the MVC formed during at least two short-lived hydrothermal periods with the bulk of orogenic gold introduced along the retrograde path of the orogenic cycle, ~25–30 million years post-peak metamorphism.
      PubDate: 2022-07-07
       
  • Retraction Note to: Mercury isotope constraints on the sources of metals
           in the Baiyangping Ag-Cu-Pb-Zn polymetallic deposits, SW China

    • Free pre-print version: Loading...

      PubDate: 2022-07-05
       
  • Insights from mineral trace chemistry on the origin of NYF and mixed
           LCT + NYF pegmatites and their mineralization at Mangodara, SW Burkina
           Faso

    • Free pre-print version: Loading...

      Abstract: Abstract The Mangodara district (southwestern of Burkina Faso, West African Craton) consists of a regional-scale Eburnean dome cored by granitoid-gneisses comprising rafts of migmatitic paragneisses and amphibolites of the Paleoproterozoic Birimian series. The occurrence of rare metal-bearing pegmatites in diffuse contact with these migmatitic and granitoid gneisses suggests that they originated from the segregation of a residual melt of these partially molten hosts. In this paper, we constrain the petrogenetic link between pegmatites and their hosts, and the mechanisms of rare metal fractionation in Lithium-Cesium-Tantalum (LCT) vs Niobium-Yttrium-Fluorine (NYF) petrogenetic signatures by the geochemistry of micas, apatite, columbite-group minerals, garnet, and zircon. Titanite-allanite pegmatites (containing titanite, allanite, epidote, zircon, and apatite as accessory minerals) and their evolved equivalent, apatite-zircon pegmatites (richer in apatite, lower K/Rb and Fe/Mn ratio in biotite but Li-depleted) are poorly mineralized metaluminous pegmatites. They display a continuous evolution trend in K/Rb and Fe/Mn in biotite and similar REE patterns in apatite, which favor an origin by segregation of residual melt within tonalitic-trondhjemitic gneiss in the core of the Mangodara dome. Garnet-columbite pegmatites containing REE-bearing phosphates and Zr-U-Th-bearing metamict minerals are mixed LCT + NYF pegmatites. Their micas, slightly enriched in Li, LREE-rich apatite, and Nb–Ta-U-rich garnet, are consistent with an origin by partial melting of a metasedimentary source, with dehydration of biotite (reservoir of Li, Rb, Nb) and dissolution of apatite-monazite (reservoir of REE). Apatite crystals in one garnet-columbite pegmatite reveal an inherited REE signature typical of apatite-zircon pegmatite, which suggests mingling of a LCT pegmatite-forming melt with the residual melt derived from crystallization of metaluminous pegmatites. Garnet-REE pegmatites, containing ilmenite-pyrophanite and euxenite-aeschynite), are NYF pegmatites that should originate from melt segregation within granodioritic gneiss associated with breakdown/entrainment of amphibole (reservoir of REE, Y) and LREE segregation by allanite and phosphates in the source. These data show that the LCT vs NYF signature of pegmatites of the Mangodara district results primarily from the chemical composition of the partially-molten source and the minerals involved in the partial melting reactions, which vary as a function of increasing depth (mica, phosphate, amphibole, garnet). The trace-element signature of anatectic peraluminous pegmatite-forming melt might then be affected by mingling with residual Nb-enriched metaluminous melt.
      PubDate: 2022-07-04
       
  • Pyrite trace element and S-Pb isotopic evidence for contrasting sources of
           metals and ligands during superimposed hydrothermal events in the Dongping
           gold deposit, North China

    • Free pre-print version: Loading...

      Abstract: Abstract The Dongping gold deposit, located near the northern margin of the North China Craton, contains ore bodies spatially associated with the Devonian Shuiquangou syenite, Cretaceous Shangshuiquan granite, and Archean metamorphic rocks. Major and trace elements and S–Pb isotopes of pyrite from two stages of gold-quartz veins and wall rocks were used to constrain the composition of hydrothermal fluids and metal sources. Stage-1 (early) pyrites are euhedral to subhedral, medium- to coarse-grained, and have low gold contents. Py1a is homogeneous with few fractures, whereas Py1b, which occurs on the edges of Py1a, is porous and has higher metal contents. Stage-2 (late) pyrites are mostly anhedral to subhedral and have smaller grain sizes and higher gold contents than Stage 1. Py2a occurs with sulfide minerals such as galena and chalcopyrite, and Py2b is porous and has the highest gold content (up to 1839 ppm) and smallest grain size. All pyrite samples yield negative δ34S values (− 7.5 to − 3.5‰), reflecting oxidized conditions during mineralization. The ~ 2‰ decrease in δ34S values from Stage 1 (− 4.3‰, − 4.9‰) to Stage 2 (− 7.0‰, − 6.4‰) may reflect a change in the fluid source and/or an increase in fO2. The Pb isotope composition of Stage-1 pyrite is suggestive of a mantle source similar to that of the Shuiquangou syenite, whereas Stage-2 pyrite has more radiogenic Pb isotopic compositions suggestive of an Archean metamorphic source. Combined with previous studies, our trace element and isotopic results indicate that the two stages of pyrite had different sources, with Stage-2 pyrite being more strongly influenced by metasedimentary rocks. We propose that the early stage of low-grade gold mineralization was related to emplacement of the Devonian Shuiquangou syenite, whereas the late stage of high-grade gold mineralization was related to emplacement of the Cretaceous Shangshuiquan granite and leaching of gold from Archean metamorphic rocks.
      PubDate: 2022-06-27
       
  • Integrated stratigraphy, lithofacies, and U–Pb geochronology of the Myra
           Falls VHMS deposits, British Columbia, Canada: implications for episodic
           volcanism and ore deposit formation

    • Free pre-print version: Loading...

      Abstract: Abstract The Late Devonian to Early Mississippian Sicker Group of Vancouver Island, British Columbia, Canada, is host to the Myra Falls polymetallic, volcanic-hosted massive sulfide (VHMS) deposits (production has exceeded 30 Mt at average grades of 5.5% Zn, 1.6% Cu, 0.6% Pb, 2.0 g/t Au, and 54.0 g/t Ag), along with numerous historic VHMS workings and occurrences. Two cycles of bimodal volcanism and marine sedimentation at Myra Falls are prospective for VHMS deposits. These cycles are defined as the lower and upper subdivisions of the Myra Formation. The lower Myra Formation consists of the H-W member, Hanging-Wall Andesite, and Lower Mixed Volcanics units. Rhyolitic rocks of the H-W member host the HW, Battle, Trumpeter Zone, Extension Zone, Gap, Ridge, and Marshall Zone orebodies. The upper Myra Formation includes the L-M-P member, Upper Mixed Volcanics and the Upper Mafic units. Rhyolitic rocks of the L-M-P member host the Lynx, Myra, and Price orebodies. Prior to this study, geological observations suggested that the H-W and L-M-P VHMS mineral deposits were likely coeval based on similar volcanic host rocks, base metal sulfide mineralization zoning, and only 200 vertical meters of stratigraphic separation. Previous attempts to date the duration of felsic volcanism at Myra Falls have resulted in relatively imprecise crystallization ages and were unable to resolve the temporal relationship between the L-M-P and H-W members and the VHMS deposits they host. New chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) and laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) U–Pb zircon geochronology yielded crystallization and maximum deposition ages of volcanic rock units from Myra Falls. This new data temporally constrains the felsic volcanic history at Myra Falls by a precise CA-ID-TIMS age of 362 ± 1 Ma for coherent rhyolite of the H-W member and a LA-ICPMS maximum depositional age of 356 ± 3 Ma for volcaniclastic rhyolite of the L-M-P member. This new geochronological data suggests there is a 3.5–11 myr time interval between the H-W and L-M-P members and therefore, a previously unrecognized unconformity exists between the lower and upper subdivisions of the Myra Formation and that the VHMS deposits of the H-W and L-M-P members were not coeval, but likely formed from temporally, distinct hydrothermal events. The results of this study, together with published age constraints from across Vancouver Island, provide a revised geochronological and lithological framework for volcanism and VHMS deposit formation within the Sicker Group. At least three Paleozoic felsic volcanic events (~ 362 Ma; ~ 355 Ma; and 310–300 Ma) host VHMS mineralization on Vancouver Island. Recognizing the specific chronostratigraphic intervals, and the lithostratigraphic setting, of VHMS deposits is important for genetic and mineral exploration models, and will aid explorers in identifying key stratigraphic units that are most prospective for VHMS mineralization.
      PubDate: 2022-06-10
      DOI: 10.1007/s00126-022-01124-0
       
  • The Black Angel deposit, Greenland: a Paleoproterozoic evaporite-related
           Mississippi Valley-type Zn–Pb deposit

    • Free pre-print version: Loading...

      Abstract: Abstract The Paleoproterozoic Mârmorilik Formation in the Karrat basin of West Greenland hosts the Black Angel Zn–Pb deposit. Chlorine-rich scapolite, zones with vuggy porosity and quartz nodules in the ore-bearing marble are herein interpreted to represent metamorphosed, vanished, and replaced evaporites, respectively. Mineralization is closely associated with anhydrite with δ34S values (5.2–12.6‰) broadly comparable to published values for Paleoproterozoic seawater sulfate. Considering the fundamental attributes of the mineralization and host sequence, a Mississippi Valley-type (MVT) model is the most obvious explanation for mineralization. Overlying the ore-bearing sequence are organic-rich semipelites and massive calcitic marbles, which may have served as seals for hydrocarbon or reduced sulfur and acted as chemical traps for deposition of the sulfidic ore. The Mârmorilik Formation contained an interlayered sulfate-rich evaporite-carbonate sequence, a common setting for MVT deposits in the late Neoproterozoic and Phanerozoic, but unique among the few known MVT deposits in the Paleoproterozoic. This ca. 1915 Ma evaporite-carbonate platform is younger than sulfate evaporites deposited during and immediately after the ca. 2220–2060 Ma Lomagundi carbon isotope excursion and records a significant seawater sulfate level during a time interval when it was assumed that it had been too low to form extensive evaporite deposits. Therefore, MVT and clastic-dominated (CD) Zn–Pb deposits in the geological record might progressively fill the apparent gap in marine sulfate evaporites and provide unique insights into Proterozoic seawater sulfate level. Considering the sequence of tectonic events that affected the Karrat basin, the mineralization took place between Nagssugtoqidian collision (< 1860 Ma) and Rinkian metamorphism (ca. 1830 Ma).
      PubDate: 2022-06-03
      DOI: 10.1007/s00126-022-01125-z
       
  • Bi/Te control on gold mineralizing processes in the North China Craton:
           Insights from the Wulong gold deposit

    • Free pre-print version: Loading...

      Abstract: Abstract The Wulong gold deposit (> 80 t Au) is located at the northeastern margin of the North China Craton (NCC). Gold in the most economically important quartz veins (Stages 2 and 3) is associated with a varied assemblage of Bi and Te minerals. Stage 2 is characterized by, in a temporal order, native gold-native bismuth-maldonite-hedleyite, bismuthinite-Bi-sulfotellurides, electrum-hessite-Bi-Pb-Ag sulfosalts, Bi-Pb sulfosalts, and Bi-Pb-sulfotellurides. All of these minerals except maldonite, electrum, hessite, and Bi-sulfosalts are present in Stage 3 veins, which also contain jonassonite and unnamed minerals with stoichiometry of Bi8Te3 and Bi5Te3. These complex Bi mineral assemblages resulted from changes in Pb, Ag, Te and Bi concentrations in reduced hydrothermal fluids both locally and temporally, from Stage 2 to 3. Texturally, approximately 85% of the gold grains are associated with almost all Bi minerals in each main-stage mineralization. Quartz-vein ores from Stages 2 and 3 have high Bi concentrations (up to 7332 ppm) and show a positive correlation between Bi and Au, with Bi/Au ratios > 10. These textural and geochemical associations, together with the occurrence of numerous droplet-like blebs and small inclusion trails of native bismuth and Bi-tellurides with native gold, maldonite, or jonassonite, suggest that Bi-rich melts may have formed from the hydrothermal fluids of Stages 2 and 3, and acted as an Au scavenger in a complex Bi-Au-Pb-Ag-Te system. Hence, the intimate association of Bi and Au at Wulong is the result of Au enrichment via the liquid bismuth collector mechanism. Unlike Wulong, however, other deposits in the NCC, such as Yangzhaiyu (Xiaoqinling district), Guilaizhuang (Jiaodong district) and Dongping (Jidong district), are characterized by low Bi concentrations, and are much richer in Te than Bi, so these systems could not generate low-melting point Bi-rich polymetallic melts. The low-sulfur Bi-Au-Pb-Ag-Te association at Wulong is consistent with that observed in reduced intrusion-related gold systems elsewhere and suggests that hydrothermal fluids may have been derived from the co-located Early Cretaceous diorite-granite porphyry dyke swarm.
      PubDate: 2022-06-02
      DOI: 10.1007/s00126-022-01120-4
       
  • Cu-sulfide mineralogy, texture, and geochemistry in the Tiegelongnan
           porphyry-epithermal copper system, Tibet, China

    • Free pre-print version: Loading...

      Abstract: Abstract The Tiegelongnan porphyry-epithermal deposit (2089 Mt @ 0.53% Cu, 0.08 g/t Au) is host to a large variety of Cu-sulfide minerals, mainly chalcopyrite, bornite, covellite, digenite, enargite, and tennantite. We used LA-ICP-MS to investigate the trace element geochemistry of the Tiegelongnan Cu-sulfides, as well as pyrite, to understand the correlation between sulfides and trace elements, gold in particular, in the porphyry and epithermal systems. Porphyry mineralization consists of stage 1 chalcopyrite-pyrite ± molybdenite, stage 2 chalcopyrite-bornite, and stage 3 covellite. Epithermal sulfides form stage 4 pyrite-alunite, stage 5 digenite-bornite-chalcopyrite, and stage 6 enargite-tennantite ± tetrahedrite. Stage 2 chalcopyrite (S2 Ccp, median = 9.7 ppm Au) is the primary porphyry Au host, and stage 6 tennantite in alunite veins (S6 Tnt-s, median = 98.0 ppm Au) is the major epithermal Au host. These Au-rich sulfides formed under higher oxidation conditions, suggesting that a high oxidation state favors the incorporation of Au in Cu-sulfides. Gold contents in coeval chalcopyrite and bornite are positively correlated to temperature, and Au is enriched in chalcopyrite over bornite at low temperatures (< 350 ℃). Positive correlations between Au and As and Te in covellite and chalcopyrite result from the reaction of As3+  + (Au+/Ag+) + Te2− ↔ 4Cu+  + S2−. Epithermal chalcopyrite and bornite contain more As and Pd than that in porphyry stages, and high contents of As, Sn, Cd, Zn, Sb, Te, Au, and Bi in epithermal enargite and tennantite are likely the result of partitioning of these elements in sulfides at low epithermal temperatures. Epithermal overprinting likely leached Cu from earlier porphyry stage sulfides to precipitate high Cu-grade epithermal mineralization. The Cu-sulfides and related trace elements show a spatial distribution, potentially useful for the exploration of overprinted porphyry-epithermal systems.
      PubDate: 2022-06-01
      DOI: 10.1007/s00126-021-01075-y
       
  • Correction to: Proceedings of the Ninth International Conference on
           

    • Free pre-print version: Loading...

      PubDate: 2022-04-07
      DOI: 10.1007/s00126-022-01108-0
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 3.235.140.84
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-