Orthopyroxenite hosted chromitite veins anomalously enriched in platinum-group minerals from the Havana-Matanzas Ophiolite, Cuba Abstract The Havana–Matanzas Ophiolite contains one of the few examples of ophiolitic platinum group minerals (PGM)-rich chromitites associated with orthopyroxenites in the mantle section of ophiolitic complexes. The chromitites occur as veins hosted by orthopyroxenite bands within mantle peridotites. The peridotites…
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2020: Petrology and geochemistry of high-Al chromitites from the Medellin Metaharzburgitic Unit (MMU), Colombia
Petrology and geochemistry of high-Al chromitites from the Medellin Metaharzburgitic Unit (MMU), Colombia Abstract The Medellin Metaharzburgitic Unit (MMU), emplaced onto the western continental margin of Pangea during Triassic time, is located in the Central Cordillera of Colombia and consists of metaharzburgites, minor metadunites and chromitite bodies (Patio Bonito and San Pedro ore deposits). The…
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2020: Diamond forms during low pressure serpentinisation of oceanic lithosphere
Diamond forms during low pressure serpentinisation of oceanic lithosphere Abstract Diamond is commonly regarded as an indicator of ultra-high pressure conditions in Earth System Science. This canonical view is challenged by recent data and interpretations that suggest metastable growth of diamond in low pressure environments. One such environment is serpentinisation of oceanic lithosphere, which produces…
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2020: Cryptic alkaline magmatism in the oceanic Caribbean arc (Camagüey area, Cuba)
Cryptic alkaline magmatism in the oceanic Caribbean arc (Camagüey area, Cuba) Abstract Mid and Late Cretaceous arc-related basaltic rocks in the Camagüey area, East Central Cuba, record an intriguing seemingly random enrichment in alkalis that suggests alkaline affinity, representing an oddity in the Greater Antilles. In this study, the petrology and geochemistry of volcanic rocks…
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2020: Nanoscale constraints on the in situ transformation of Ru–Os–Ir sulfides to alloys at low temperature
Nanoscale constraints on the in situ transformation of Ru–Os–Ir sulfides to alloys at low temperature Abstract We report new results of a combined focused ion beam high-resolution transmission electron microscopy (FIB/HRTEM) investigation of two grains of platinum-group minerals (PGM) corresponding to the laurite (RuS2)-erlichmanite (OsS2) solid solution series. The grains are included within unaltered chromite…
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2020: Ophiolite hosted chromitite formed by supra-subduction zone peridotite –plume interaction
Ophiolite hosted chromitite formed by supra-subduction zone peridotite –plume interaction Abstract Chromitite bodies hosted in peridotites typical of suboceanic mantle (s.l. ophiolitic) are found in the northern and central part of the Loma Caribe Peridotite in the Cordillera Central of the Dominican Republic. These chromitites are massive pods of small size (less than a few…
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2020: The Petrologic Nature of the “Medellín Dunite” Revisited: An Algebraic Approach and Proposal of a New Definition of the Geological Body
The Petrologic Nature of the “Medellín Dunite” Revisited: An Algebraic Approach and Proposal of a New Definition of the Geological Body Abstract The “Medellín Dunite”, the main ultramafic body of the Central Cordillera of Colombia, constitutes a fragment of oceanic lithospheric mantle formed at a back–arc basin/incipient arc scenario emplaced onto the western continental margin…
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2020: Fe-Ti-Zr metasomatism in the oceanic mantle due to extreme differentiation of tholeiitic melts (Moa-Baracoa ophiolite, Cuba)
Fe-Ti-Zr metasomatism in the oceanic mantle due to extreme differentiation of tholeiitic melts (Moa-Baracoa ophiolite, Cuba) Abstract Ti-rich amphibole, Mg-rich ilmenite, baddeleyite, zirconolite, srilankite, and zircon are important high-field-strength elements (HFSE) bearing phases in the Potosí chromitite bodies located in the Moho Transition Zone of the Cretaceous Moa-Baracoa suprasubduction zone ophiolite (eastern Cuba). Such HFSE-bearing…
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2020: Precious metals in magmatic Fe-Ni-Cu sulfides from the Potosí chromitite deposit, eastern Cuba
Precious metals in magmatic Fe-Ni-Cu sulfides from the Potosí chromitite deposit, eastern Cuba Abstract We report new results of a combined focused ion beam and high-resolution transmission electron microscopy (FIB/HRTEM) investigation of platinum-group elements (PGE)-rich base-metal sulfides. The Ni-Fe-Cu base-metal sulfides (BMS) studied are millerite (NiS), pentlandite [(Ni,Fe)9S8], pyrite (FeS2), and chalcopyrite (CuFeS2). These BMS…
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