Artículos de revistas: "Cu-PGE"

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Sproule, Rebecca, Steve Beresford y Reid Keays. "Ni–Cu–PGE magmatic mineralisation". Applied Earth Science 116, n.º 4 (diciembre de 2007): 151. http://dx.doi.org/10.1179/174327507x272012.

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2

Lu, Yiguan, C. Michael Lesher y Jun Deng. "Geochemistry and genesis of magmatic Ni-Cu-(PGE) and PGE-(Cu)-(Ni) deposits in China". Ore Geology Reviews 107 (abril de 2019): 863–87. http://dx.doi.org/10.1016/j.oregeorev.2019.03.024.

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3

Sunder Raju, P. V. "12th International Ni-Cu-(PGE) Symposium". Journal of the Geological Society of India 80, n.º 2 (agosto de 2012): 293. http://dx.doi.org/10.1007/s12594-012-0142-8.

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4

Moilanen, M., E. Hanski, J. Konnunaho, T. Törmänen, S. H. Yang, Y. Lahaye, H. O’Brien y J. Illikainen. "Composition of iron oxides in Archean and Paleoproterozoic mafic-ultramafic hosted Ni-Cu-PGE deposits in northern Fennoscandia: application to mineral exploration". Mineralium Deposita 55, n.º 8 (11 de enero de 2020): 1515–34. http://dx.doi.org/10.1007/s00126-020-00953-1.

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Abstract Using electron probe microanalyzer (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), we analyzed major and trace element compositions of iron oxides from Ni-Cu-PGE sulfide deposits hosted by mafic-ultramafic rocks in northern Fennoscandia, mostly focusing on Finland. The main research targets were the Archean Ruossakero Ni-(Cu) deposit; Tulppio dunite and related Ni-PGE mineralization; Hietaharju, Vaara, and Tainiovaara Ni-(Cu-PGE) deposits; and Paleoproterozoic Lomalampi PGE-(Ni-Cu) deposit. In addition, some reference samples from the Pechenga (Russia), Jinchuan (China), and Kevitsa (Finland) Ni-Cu-PGE sulfide deposits, and a barren komatiite sequence in the Kovero area (Finland) were studied. Magnetite and Cr-magnetite show a wide range of trace element compositions as a result of the variation of silicate and sulfide melt compositions and their post-magmatic modification history. Most importantly, the Ni content in oxide shows a positive correlation with the Ni tenor of the sulfide phase in equilibrium with magnetite, regardless of whether the sulfide assemblage is magmatic or post-magmatic in origin. The massive sulfide samples contain an oxide phase varying in composition from Cr-magnetite to magnetite, indicating that Cr-magnetite can crystallize directly from sulfide liquid. The Mg concentration of magnetites in massive sulfide samples is lowest among the samples analyzed, and this can be regarded as a diagnostic feature of an oxide phase crystallized together with primitive Fe-rich MSS (monosulfide solid solution). Our results show that magnetite geochemistry, plotted in appropriate discrimination diagrams, together with petrographical observations could be used as an indicator of potential Ni-(Cu-PGE) mineralization.

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5

Smith, W. D., W. D. Maier y I. Bliss. "Contact-style magmatic sulphide mineralisation in the Labrador Trough, northern Quebec, Canada: implications for regional prospectivity". Canadian Journal of Earth Sciences 57, n.º 7 (julio de 2020): 867–83. http://dx.doi.org/10.1139/cjes-2019-0137.

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The Labrador Trough in northern Quebec is currently the focus of ongoing exploration for magmatic Ni-Cu-platinum group element (PGE) sulphide ores. This geological belt hosts voluminous basaltic sills and lavas of the Montagnais Sill Complex, which are locally emplaced among sulphidic metasedimentary country rocks. The recently discovered Idefix PGE-Cu prospect represents a stack of gabbroic sills that host stratiform patchy disseminated to net-textured sulphides (0.2–0.4 g/t PGE+Au) over a thickness of ∼20 m, for up to 7 km. In addition, globular sulphides occur at the base of the sill, adjacent to the metasedimentary floor rocks. Whole-rock and PGE geochemistry indicates that the sills share a common source and that the extracted magma underwent significant fractionation before emplacement in the upper crust. To develop the PGE-enriched ores, sulphide melt saturation was attained before final emplacement, peaking at R factors of ∼10 000. Globular sulphides entrained along the base of the sill ingested crustally derived arsenic and were ultimately preserved in the advancing chilled margin.

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6

Koerber, Alexander y Joyashish Thakurta. "PGE-Enrichment in Magnetite-Bearing Olivine Gabbro: New Observations from the Midcontinent Rift-Related Echo Lake Intrusion in Northern Michigan, USA". Minerals 9, n.º 1 (29 de diciembre de 2018): 21. http://dx.doi.org/10.3390/min9010021.

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The Echo Lake intrusion in the Upper Peninsula (UP) of Michigan, USA, was formed during the 1.1 Ga Midcontinent Rift event in North America. Troctolite is the predominant rock unit in the intrusion, with interlayered bands of peridotite, mafic pegmatitic rock, olivine gabbro, magnetite-bearing gabbro, and anorthosite. Exploratory drilling has revealed a platinum group element (PGE)-enriched zone within a 45 m thick magnetite-ilmenite-bearing olivine gabbro unit with grades up to 1.2 g/t Pt + Pd and 0.3 wt. % Cu. Fine, disseminated grains of sulfide minerals such as pyrrhotite and chalcopyrite occur in the mineralized interval. Formation of Cu-PGE-rich sulfide minerals might have been caused by sulfide melt saturation in a crystallizing magma, which was triggered by a sudden decrease in fO2 upon the crystallization and separation of titaniferous magnetite. This PGE-enriched zone is comparable to other well-known reef-like PGE deposits, such as the Sonju Lake deposit in northern Minnesota.

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Nielsen, T. F. D., N. S. Rudashevsky, V. N. Rudashevsky, S. M. Weatherley y J. C. Ø. Andersen. "Elemental Distributions and Mineral Parageneses of the Skaergaard PGE–Au Mineralization: Consequences of Accumulation, Redistribution, and Equilibration in an Upward-Migrating Mush Zone". Journal of Petrology 60, n.º 10 (1 de octubre de 2019): 1903–34. http://dx.doi.org/10.1093/petrology/egz057.

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Abstract The Skaergaard PGE–Au mineralization, aka the Platinova Reef, is a syn-magmatic Platinum Group Element (PGE) and gold (Au) mineralization that formed after crystallization of ∼74% of the bulk melt of the intrusion. It is hosted in a more than 600 m deep and bowl-shaped succession of gabbroic macro-rhythmic layers in the upper 100 m of the Middle Zone. The precious metal mineralization comprises a series of concordant, but compositionally zoned, mineralization levels identified by distinct PGE, Au and Cu peaks. They formed due to local sulphide saturation in stratiform concentrations of interstitial and evolved mush melts in six MLs over > 2000 years. The PGE–Au mineralization is compared to a stack of gold-rimmed saucers of PGE-rich gabbro of upward decreasing size. Fundamentally different crystallization and mineralization scenarios have been proposed for the mineralization, including offset reef type models based on sulphide saturation in the melt from which the silicate host crystallized, and the here argued model which restricts the same processes to the melt of the inward migrating mush zone of the magma chamber. The latter is supported by: i) a 3 D summary of the parageneses of precious metal minerals and phases (> 4000 grains) from 32 samples across the mineralization; ii) a 3 D compilation of all bulk rock assay data; and iii) a principal component analysis (PCA) of PGE, Au, Cu, and selected major and trace elements. In the main PGE-mineralization level (Pd5 alias Pd-Zone) the precious metal mineral paragenesis varies across the intrusion with precious metal sulphides and Au-alloys at the W-margin to Precambrian basement, precious metal plumbide and Au- and Ag-alloys at the E-margin to flood basalts, and skaergaardite (PdCu) and intermetallic compounds and alloys of PGE–Au and Cu in the central parts of the mineralization. Precious metal parageneses are distinct for a given sector of the intrusion, i.e. drill core (local control), rather than for a given stratigraphic or temporal interval in the accumulated gabbros. The precious metal ‘grade times width’ number (average g/t x metres) for the mineralization at an upper and a lower cut off of 100 ppb PGE or Au increases from ∼20 to ∼45 g toward the centre of the mineralization due to ponding of precious metal bearing melt. A strong increase in (Pd+Pt+Au)/Cu and dominance of (PdCu) alloys in the lower and central parts of the mineralization demonstrate the partial dissolution of droplets of Cu-rich sulphide melt and fractionation of precious metal ratios. The precious metal parageneses, the distribution of precious metals in the mineralization, and the PCA support initial accumulation of precious metals in the melt of the mush in the floor, followed by equilibration, sulphide saturation, and reactions with residual and immiscible Fe-rich silicate melt in a series of macro-rhythmic layers in the stratified and upward migrating mush zone in the floor of the magma chamber. Syn-magmatic and upward redistribution of precious metals sets the Skaergaard PGE–Au Mineralization apart from conventional reef type and offset-reef type precious metal mineralizations, and characterize ‘Skaergaard type’ precious metal deposits.

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8

Liao, Yuan, Qian Li, Ying Yue y Shijun Shao. "Selective electrochemical determination of trace level copper using a salicylaldehyde azine/MWCNTs/Nafion modified pyrolytic graphite electrode by the anodic stripping voltammetric method". RSC Advances 5, n.º 5 (2015): 3232–38. http://dx.doi.org/10.1039/c4ra12342e.

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9

Sluzhenikin, Sergey F. y Andrey V. Mokhov. "Gold and silver in PGE–Cu–Ni and PGE ores of the Noril’sk deposits, Russia". Mineralium Deposita 50, n.º 4 (19 de agosto de 2014): 465–92. http://dx.doi.org/10.1007/s00126-014-0543-2.

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10

Sappin, A. A., M. Constantin, T. Clark y O. van Breemen. "Geochemistry, geochronology, and geodynamic setting of Ni–Cu ± PGE mineral prospects hosted by mafic and ultramafic intrusions in the Portneuf–Mauricie Domain, Grenville Province, QuebecGéologie Québec Contribution 8439-2008-2009-5. Geological Survey of Canada Contribution 20080511." Canadian Journal of Earth Sciences 46, n.º 5 (mayo de 2009): 331–53. http://dx.doi.org/10.1139/e09-022.

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The Portneuf–Mauricie Domain in the Grenville Province consists of the Montauban group rocks (1.45 Ga), intruded by the La Bostonnais complex plutons (1.40–1.37 Ga). This assemblage was formed in a magmatic arc setting. The sequence was intruded by mafic–ultramafic tholeiitic plutons, some of which host Ni–Cu ± PGE (platinum group element) prospects. U–Pb zircon ages determined from these plutons indicate that the mineralized intrusions were emplaced between 1.40 and 1.39 Ga and that they are coeval with the La Bostonnais complex plutons. The Ni–Cu ± PGE-bearing intrusions have mature island-arc trace element signatures, with strong chemical evidence for differentiation (Mg# and Cr content; MgO and TiO2 contents) and crustal contamination (enrichments in K2O, Rb, Ba, Th, and light rare-earth elements; Th/Yb and Ta/Yb ratios). However, one intrusion displays a back-arc trace element signature associated with evidence for weak crust assimilation. The evolution of the Portneuf–Mauricie Domain is interpreted as follows: (1) 1.45 Ga — Northwesterly directed Andean-type subduction beneath the Laurentian craton margin. Furthermore, northwest-dipping intraoceanic subduction offshore from the continent formed the Montauban island arc. (2) 1.45 to 1.40 Ga — Andean-type subduction led to the formation of a back-arc basin behind the Montauban arc. (3) 1.40 Ga — Emplacement of the La Bostonnais complex plutons, some hosting Ni–Cu ± PGE prospects, into the Montauban arc. (4) 1.39 Ga — Subduction beneath Laurentia led to arc–continent collision and to closure of the back-arc basin. Intrusion of the Ni–Cu ± PGE-bearing plutons ceased. (5) 1.37 Ga — Intrusion of all La Bostonnais complex plutons ceased.

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Припачкин, Павел Валентинович. "О роли дайковых и жильных тел в распределении Cu-Ni-PGE минерализации в Мончегорском расслоенном комплексе (Кольский полуостров, Россия)". Вестник ВГУ. Серия: Геология, n.º 2 (6 de abril de 2018): 84–92. http://dx.doi.org/10.17308/geology.2018.2/1526.

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Приводится краткий обзор роли дайковых и жильных тел в составе дифференцированных интрузий для концентрации Cu-Ni-PGE минерализации. В результате наших исследований в пределах Мончегорского расслоенного ультрамафит-мафитового комплекса Кольского полуострова установлено, что минерализация Южносопчинского расслоенного массива, связана не с расслоенной серией пород (пироксениты, нориты, габбронориты), а с жильными телами магнетит-амфибол-плагиоклазового состава в пироксенитах краевой серии. Предполагается также, что перспективное PGE оруденение зоны сочленения Мончеплутона и Мончетундровской интрузии относится не к рифовому, а к контактному типу, переотложенному в ходе позднемагматического жилообразования. Учитывая данные исследований геологов ОАО «Центрально-Кольская экспедиция» о новом типе жильной Сu-PGE минерализации на участке Западный Ниттис, делается вывод о важности данного типа оруденения (наряду с рифовым) в общем балансе Мончегорского комплекса.

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12

Zhang, Wei, Gu Chang Zhu y Yan Zhi Wu. "The Enrichment Mechanism of PGE and Characteristic of MSZ in HW Mining Area in Great Dyke Zimbabwe". Advanced Materials Research 616-618 (diciembre de 2012): 90–95. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.90.

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Zimbabwe Great Dyke is a mafic-ultramafic lithosome intruded the Zimbabwe Craton. MSZ(Main Sulfide Zone) is the most important layer which contains substantial amount of PGE(Platinum Group Elements). PGE are concentrated in bottom of MSZ layer because of the intimate relationship between the content of Cu&Ni and enrichment of PGE. Acid vein rocks did not formed in the same period with the ore and adjacent rocks. Plenty of sulfide can be found in MSZ in pyroxenite, Sulfide in ore was owe to homogeneous of geochemistry process in the magamtic segregation cycle, while them in gabbro and fractures were simply by the post magmatic thermal solution activities.

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13

Akizawa, Norikatsu, Tetsu Kogiso, Akira Miyake, Akira Tsuchiyama, Yohei Igami y Masayuki Uesugi. "Formation process of sub-micrometer-sized metasomatic platinum-group element-bearing sulfides in a Tahitian harzburgite xenolith". Canadian Mineralogist 58, n.º 1 (16 de enero de 2020): 99–114. http://dx.doi.org/10.3749/canmin.1800082.

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ABSTRACT Base-metal sulfides (BMSs) are minerals that host platinum-group elements (PGE) in mantle peridotites and significantly control the bulk PGE content. They have been investigated in detail down to the sub-micrometer scale to elucidate PGE behavior in the Earth's interior. Base-metal sulfides are supposedly subjected to supergene and seawater weathering, leading to the redistribution of PGEs at low temperatures. Careful and thorough measurements of BMSs are thus required to elucidate PGE behavior in the Earth's interior. In the present study, a sub-micrometer-sized PGE-bearing sulfide inclusion in a clinopyroxene crystal in a harzburgite xenolith from Tahiti (Society Islands, French Polynesia) was investigated in detail (down to the sub-micrometer scale) using transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM-EDS). The sulfide inclusion is of carbonatitic metasomatic origin, as it is enveloped by carbonaceous glass, and forms a planar inclusion array with other PGE-bearing sulfide inclusions. The following sulfide phases were identified using TEM-EDS: Fe- and Ni-rich monosulfide solid solutions (MSSs), Fe- and Ni-rich pentlandite, sugakiite, heazlewoodite, chalcopyrite, and Cu-Ir-Pt-Rh-thiospinel (cuproiridsite–malanite–cuprorhodsite). We established the formation process of the metasomatic PGE-bearing sulfide inclusion by considering morphological and mineral characteristics in addition to the chemical composition. A primary MSS first crystallized from metasomatic sulfide melt at ca. 1000 °C, followed by the crystallization of an intermediate solid solution (ISS) below 900 °C. A high-form (high-temperature origin) Fe-rich pentlandite simultaneously crystallized with the primary MSS below ca. 850 °C and recrystallized into a low-form (low-temperature origin) Fe-rich pentlandite below ca. 600 °C. The primary MSS decomposed to Fe- and Ni-rich MSSs, low-form Ni-rich pentlandite, sugakiite, and heazlewoodite. The ISS decomposed to chalcopyrite below ca. 600 °C. Meanwhile, a Cu-Ir-Pt-Rh-thiospinel crystallized directly from the evolved Cu-rich sulfide melt below ca. 760 °C. Thus, Ir, Pt, and Rh preferentially partitioned into the melt phase during the crystallization process of the metasomatic sulfide melt. Metasomatic sulfide melts could be a significant medium for the transport and condensation of Pt together with Ir and Rh during the fractionation process in the Earth's interior. We hypothesize that the compositional variability of PGEs in carbonatites is due to the separation of sulfide melt leading to the loss of PGEs in the carbonatitic melts.

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Thériault, Robert D., Sarah-Jane Barnes y Mark J. Severson. "The influence of country-rock assimilation and silicate to sulfide ratios (R factor) on the genesis of the Dunka Road Cu – Ni – platinum-group element deposit, Duluth Complex, Minnesota". Canadian Journal of Earth Sciences 34, n.º 4 (1 de abril de 1997): 375–89. http://dx.doi.org/10.1139/e17-033.

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The Dunka Road deposit is one of several Cu – Ni – platinum-group element (PGE) sulfide occurrences found along the northwestern margin of the Duluth Complex, where the host troctolitic rocks are in contact with metasedimentary rocks of the Animikie Group. Magma contamination through assimilation of sulfidic argillaceous country rocks is generally recognized as having played a key role in the genesis of the mineralization. Three main types of disseminated sulfide mineralization have been identified within the Dunka Road deposit: (i) norite-hosted sulfides, (ii) troctolite-hosted sulfides, and (iii) PGE-rich sulfide horizons. The norite-hosted sulfides are found either adjacent to country-rock xenoliths or near the basal contact. The troctolite-hosted sulfides form the bulk of the deposit, and occur throughout the lower 250 m of the intrusion. The PGE-rich sulfide horizons are typically localized directly beneath ultramafic layers. The composition of the different types of sulfide occurrences is modelled using Cu/Pd ratios. It is shown that each type results from the interplay of two main parameters, namely the degree of magma contamination and the silicate magma to sulfide melt ratio (R factor). The norite-hosted sulfides formed at low R factors and high degrees of contamination, as expressed by their PGE-depleted nature, low Se/S ratios, and elevated content in pyrrhotite and arsenide minerals. The troctolite-hosted sulfides formed at moderate R factors and small degrees of contamination, as shown by their moderate PGE content and mantle-like Se/S ratios. Finally, the PGE-rich sulfide horizons are modelled using elevated R factors from an uncontaminated parental magma, which is substantiated by their elevated noble metal content and Se/S ratios, and low pyrrhotite to precious metal sulfide ratio.

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15

Jowitt, S. M. y R. R. Keays. "Shale-hosted Ni–(Cu–PGE) mineralisation: a global overview". Applied Earth Science 120, n.º 4 (diciembre de 2011): 187–97. http://dx.doi.org/10.1179/1743275812z.00000000026.

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16

Lesher, C. M. y P. C. Lightfoot. "Preface for thematic issue on Ni–Cu–PGE deposits". Mineralium Deposita 47, n.º 1-2 (5 de agosto de 2011): 1–2. http://dx.doi.org/10.1007/s00126-011-0379-y.

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17

Duran, Charley J., Sarah-Jane Barnes, Eduardo T. Mansur, Sarah A. S. Dare, L. Paul Bédard y Sergey F. Sluzhenikin. "Magnetite Chemistry by LA-ICP-MS Records Sulfide Fractional Crystallization in Massive Nickel-Copper-Platinum Group Element Ores from the Norilsk-Talnakh Mining District (Siberia, Russia): Implications for Trace Element Partitioning into Magnetite". Economic Geology 115, n.º 6 (1 de septiembre de 2020): 1245–66. http://dx.doi.org/10.5382/econgeo.4742.

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Abstract Mineralogical and chemical zonations observed in massive sulfide ores from Ni-Cu-platinum group element (PGE) deposits are commonly ascribed to the fractional crystallization of monosulfide solid solution (MSS) and intermediate solid solution (ISS) from sulfide liquid. Recent studies of classic examples of zoned orebodies at Sudbury and Voisey’s Bay (Canada) demonstrated that the chemistry of magnetite crystallized from sulfide liquid was varying in response to sulfide fractional crystallization. Other classic examples of zoned Ni-Cu-PGE sulfide deposits occur in the Norilsk-Talnakh mining district (Russia), yet magnetite in these orebodies has received little attention. In this contribution, we document the chemistry of magnetite in samples from Norilsk-Talnakh, spanning the classic range of sulfide composition, from Cu poor (MSS) to Cu rich (ISS). Based on textural features and mineral associations, four types of magnetite with distinct chemical composition are identified: (1) MSS magnetite, (2) ISS magnetite, (3) reactional magnetite (at the sulfide-silicate interface), and (4) hydrothermal magnetite (resulting from sulfide-fluid interaction). Compositional variability in lithophile and chalcophile elements records sulfide fractional crystallization across MSS and ISS magnetites and sulfide interaction with silicate minerals (reactional magnetite) and fluids (hydrothermal magnetite). Estimated partition coefficients for magnetite in sulfide systems are unlike those in silicate systems. In sulfide systems, all lithophile elements are compatible and chalcophile elements tend to be incompatible with magnetite, but in silicate systems some lithophile elements are incompatible and chalcophile elements are compatible with magnetite. Finally, comparison with magnetite data from other Ni-Cu-PGE sulfide deposits pinpoints that the nature of parental silicate magma, degree of sulfide evolution, cocrystallizing phases, and alteration conditions influence magnetite composition.

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Hall, M. F., B. Lafrance y H. L. Gibson. "Emplacement of sharp-walled sulfide veins during the formation and reactivation of impact-related structures at the Broken Hammer Mine, Sudbury, Ontario". Canadian Journal of Earth Sciences 57, n.º 10 (octubre de 2020): 1149–66. http://dx.doi.org/10.1139/cjes-2019-0229.

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Broken Hammer is a hybrid Cu–Ni–Platinum Group Element (PGE) footwall deposit located in Archean basement rocks below the impact-induced Sudbury Igneous Complex (SIC), Canada. The deposit consists of massive chalcopyrite veins surrounded by thin epidote, actinolite, and quartz selvedges and low-sulfide, high-PGE mineralization consisting of disseminated chalcopyrite (<5%) and platinum group minerals, associated with Ni-bearing chlorite overprinting alteration patches of epidote, actinolite, and quartz. The veins are grouped into five steeply-dipping sets, striking northeast-, southwest-, southeast-, south-, and east–west, which were emplaced along impact-related fractures that were reactivated multiple times during stabilization of the crater floor. Early reactivation of the fractures created pathways for the migration of hydrothermal fluids from which quartz and chlorite precipitated sealing the fractures. Renewed slip shattered the quartz–chlorite veins into fragments that were incorporated in massive sulfide veins that crystallized from fractionated sulfide melts or from high temperature (400–500 °C) hydrothermal fluids, which migrated outward into the basement rocks from a cooling and crystallizing SIC melt sheet. Hydrothermal fluids syn-genetic with the epidote–actinolite–quartz alteration distributed the PGE into the footwall rocks, or late hydrothermal fluids associated with the Ni-bearing chlorite leached Ni and PGMs from the sulfide veins and redistributed them to form low-sulfide, high-PGE zones in the footwall rocks. During post-impact tectonic events, slip at temperatures below the brittle–ductile transition for chalcopyrite (<200 °C to 250 °C) produced striations along the vein margins. The Broken Hammer deposit exemplifies how Cu–Ni–PGE footwall deposits formed by the reactivation of impact-related fractures that provided conduits for the migration of melts and hydrothermal fluids.

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Martínez, C., F. Tornos, C. Casquet y C. Galindo. "4-1: The Aguablanca Ni–(Cu–PGE) deposit, SW Spain". Ore Geology Reviews 27, n.º 1-4 (noviembre de 2005): 164–65. http://dx.doi.org/10.1016/j.oregeorev.2005.07.019.

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20

Makkonen, Hannu V., Tapio Halkoaho, Jukka Konnunaho, Kalevi Rasilainen, Asko Kontinen y Pasi Eilu. "Ni-(Cu-PGE) deposits in Finland – Geology and exploration potential". Ore Geology Reviews 90 (noviembre de 2017): 667–96. http://dx.doi.org/10.1016/j.oregeorev.2017.06.008.

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21

Song, Xieyan. "Magmatic Ni-Cu and PGE Deposits: Geology, Geochemistry, and Genesis". Geoscience Frontiers 3, n.º 6 (noviembre de 2012): 945. http://dx.doi.org/10.1016/j.gsf.2012.05.002.

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22

Acosta-Góngora, P., S. J. Pehrsson, H. Sandeman, E. Martel y T. Peterson. "The Ferguson Lake deposit: an example of Ni–Cu–Co–PGE mineralization emplaced in a back-arc basin setting?" Canadian Journal of Earth Sciences 55, n.º 8 (agosto de 2018): 958–79. http://dx.doi.org/10.1139/cjes-2017-0185.

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The world’s largest Ni–Cu–Platinum group element (PGE) deposits are dominantly hosted by ultramafic rocks within continental extensional settings (e.g., Raglan, Voisey’s Bay), resulting in a focus on exploration in similar geodynamic settings. Consequently, the economic potential of other extensional tectonic environments, such as ocean ridges and back-arc basins, may be underestimated. In the northeastern portion of the ca. 2.7 Ga Yathkyed greenstone belt of the Chesterfield block (western Churchill Province, Canada), the Ni–Cu–Co–PGE Ferguson Lake deposit is hosted by >2.6 Ga hornblenditic to gabbroic rocks of the Ferguson Lake Igneous Complex (FLIC), which is metamorphosed up to amphibolitic facies. The FLIC has a basaltic composition (Mg# = 31–72), flat to slightly negatively sloped normalized trace element patterns (La/YbPM = 0.7–3.5), and negative Zr, Ti, and Nb anomalies. The FLIC rocks are geochemically similar to the 2.7 Ga back-arc basin tholeiitic basalts from the adjacent Yathkyed and MacQuoid greenstone belts (Mg# = 30–67; La/YbPM = 0.3–3.0), but the Ferguson Lake intrusions appear to be more crustally contaminated. We interpret the FLIC to have formed in an equivalent back-arc basin setting. This geodynamic setting is rare for the formation of Ni–Cu–PGE occurrences, and only few examples of this tectonic environment (or variations of it, e.g., rifted back-arc) are found in other Proterozoic and Archean sequences (e.g., Lorraine deposit, Quebec). We suggest that back-arc basin-derived mafic rocks within the Yathkyed and other Neoarchean greenstone belts of the Chesterfield block (MacQuoid and Angikuni) could represent important targets for future mineral exploration.

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23

Järvinen, Ville, Tapio Halkoaho, Jukka Konnunaho, Jussi S. Heinonen y O. Tapani Rämö. "Parental magma, magmatic stratigraphy, and reef-type PGE enrichment of the 2.44-Ga mafic-ultramafic Näränkävaara layered intrusion, Northern Finland". Mineralium Deposita 55, n.º 8 (31 de diciembre de 2019): 1535–60. http://dx.doi.org/10.1007/s00126-019-00934-z.

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AbstractAbout 20 mafic-ultramafic layered intrusions in the northern Fennoscandian shield were emplaced during a widespread magmatic event at 2.5–2.4 Ga. The intrusions host orthomagmatic Ni-Cu-PGE and Cr-V-Ti-Fe deposits. We update the magmatic stratigraphy of the 2.44-Ga Näränkävaara mafic-ultramafic body, northeastern Finland, on the basis of new drill core and outcrop observations. The Näränkävaara body consists of an extensive basal dunite (1700 m thick), and a layered series comprising a peridotitic–pyroxenitic ultramafic zone (600 m thick) and a gabbronoritic–dioritic mafic zone (700 m thick). Two reversals are found in the layered series. The composition of the layered series parental magma was approximated using a previously unidentified marginal series gabbronorite. The parental magma was siliceous high-Mg basalt with high MgO, Ni, and Cr, but also high SiO2 and Zr, which suggests primary magma contamination by felsic crust. Cu/Pd ratio below that of primitive mantle implies PGE-fertility. The structural position of the marginal series indicates that the thick basal dunite represents an older wallrock for the layered intrusion. A subeconomic reef-type PGE-enriched zone is found in the border zone between the ultramafic and mafic zones and has an average thickness of 25 m with 150–250 ppb of Pt + Pd + Au. Offset-type metal distribution and high sulfide tenor (50–300 ppm Pd) and R-factor (105) suggest reef formation by sulfide saturation induced by fractional crystallization. The reef-forming process was probably interrupted by influx of magma related to the first reversal. Metal ratios suggest that this replenishing magma was PGE-depleted before emplacement.

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24

Prendergast, M. D. "Variant Offset-Type Platinum Group Element Reef Mineralization in Basal Olivine Cumulates of the Kapalagulu Intrusion, Western Tanzania". Economic Geology 116, n.º 4 (1 de junio de 2021): 1011–33. http://dx.doi.org/10.5382/econgeo.4816.

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Abstract The Kapalagulu intrusion in eastern Tanzania hosts a major, 420-m-thick, stratiform/stratabound platinum group element (PGE)-bearing sulfide zone—the Lubalisi reef—within a prominent, chromititiferous, harzburgite unit close to its stratigraphic base. Several features of the vertical base and precious metal distributions (in a composite stratigraphic section based upon two deep exploration drill holes) display similarities to those of offset-type PGE reefs that formed under the overall control of Rayleigh fractionation: (1) composite layering (at several scales) defined by systematic vertical variations of sulfide and precious metal contents and intermetallic ratios, indicating repeated cycles of PGE enrichment and depletion in the order Pd-Pt-Au-Cu, and (2) in the lower part of the reef, stratigraphic offsets of the precious metal peaks below peak sulfide (Cu) content. The form and geochemistry of the reef are consistent with overturns of basal liquid layers within a liquid layering system (i.e., stable density-driven stratification of a magma chamber), plus at least two minor inputs of parental magma during which the resident magma was recharged with sulfur and metals, and the effective depletion of precious metals in the magma midway through reef development. The Lubalisi reef differs from classic offset-type PGE reefs, however, principally because individual Pd, Pt, and Au enrichment peaks are coincident, not offset. The reef is set apart from other offset-type PGE reefs in three additional ways: (1) its association with olivine cumulates that crystallized soon after initial magma emplacement and well below the first appearance of cumulus pyroxene or plagioclase (implying attainment of sulfide saturation and precious metal enrichment without prolonged concentration of sulfur and chalcophile metals by normal magma cooling and differentiation), (2) the probable role of chromite crystallization in not only triggering sulfide segregation during reef formation but also facilitating precious metal enrichment in the early stages of reef development, and (3) its great width. The early stage of fractionation may also help explain the coincident precious metal peaks through its effect on apparent precious metal partition coefficients.

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25

MA, GEORGE S. K., JOHN MALPAS, JIAN-FENG GAO, KUO-LUNG WANG, LIANG QI y COSTAS XENOPHONTOS. "Platinum-group element geochemistry of intraplate basalts from the Aleppo Plateau, NW Syria". Geological Magazine 150, n.º 3 (10 de diciembre de 2012): 497–508. http://dx.doi.org/10.1017/s0016756812000696.

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AbstractEarly–Middle Miocene intraplate basalts from the Aleppo Plateau, NW Syria have been analysed for their platinum-group elements (PGEs). They contain extremely low PGE abundances, comparable with most alkali basalts, such as those from Hawaii, and mid-ocean ridge basalts. The low abundances, together with high Pd/Ir, Pt/Ir, Ni/Ir, Cu/Pd, Y/Pt and Cu/Zr are consistent with sulphide fractionation, which likely occurred during partial melting and melt extraction within the mantle. Some of the basalts are too depleted in PGEs to be explained solely by partial melting of a primitive mantle-like source. Such ultra-low PGE abundances, however, are possible if the source contains some mafic lithologies. Many of the basalts also exhibit suprachondritic Pd/Pt ratios of up to an order of magnitude higher than primitive mantle and chondrite, an increase too high to be attributable to fractionation of spinel and silicate minerals alone. The elevated Pd/Pt, associated with a decrease in Pt but not Ir and Ru, are also inconsistent with removal of Pt-bearing PGE minerals or alloys, which should have concurrently lowered Pt, Ir and Ru. In contrast, melting of a metasomatized source comprising sulphides whose Pt and to a lesser extent Rh were selectively mobilized through interaction with silicate melts, may provide an explanation.

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26

Barkov, Andrei Y., Gennadiy I. Shvedov, Andrey A. Nikiforov y Robert F. Martin. "Platinum-group minerals from Seyba, Eastern Sayans, Russia, and substitutions in the PGE-rich pentlandite and ferhodsite series". Mineralogical Magazine 83, n.º 4 (12 de abril de 2019): 531–38. http://dx.doi.org/10.1180/mgm.2019.16.

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AbstractChromitite zones associated with ultramafic units of the Lysanskiy layered complex of dunite–peridotite–gabbro composition could well represent the primary source for the placers bearing platinum-group minerals (PGM) of the entire drainage of the River Sisim and its tributaries, the rivers Ko and Seyba, eastern Sayans. Alluvial gold present in the placers of River Seyba, as elsewhere in the Sisim Placer Zone, reflects mineralisation during a recent period of tectonic activity. We focus on the PGM in the Seyba suite, and in particular on the attributes of pentlandite enriched in platinum-group-elements (PGE) and the compositionally similar and recently defined ferhodsite, which were trapped in host grains of Os–Ir–Ru alloy. Both minerals formed from small volumes of fractionated Fe–Ni–Cu melt considerably enriched in the PGE. In the Seyba suite, as in several others, the amounts of PGE in ferhodsite exceeds that in pentlandite, which results in a greater proportion of vacancies than in pentlandite.

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27

Barkov, Andrei Y., Nadezhda D. Tolstykh, Gennadiy I. Shvedov y Robert F. Martin. "Ophiolite-related associations of platinum-group minerals at Rudnaya, western Sayans and Miass, southern Urals, Russia". Mineralogical Magazine 82, n.º 3 (18 de abril de 2018): 515–30. http://dx.doi.org/10.1180/mgm.2018.82.

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ABSTRACTWe describe similar assemblages of minerals found in two placers in Russia, both probably derived from an ophiolitic source. The first is located along the River Rudnaya in the western Sayan province, Krasnoyarskiy kray, and the second pertains to the Miass placer zone, Chelyabinsk oblast, in the southern Urals. The platinum-group element (PGE) mineralization in both cases is mostly (at least 80%) represented by alloy minerals in the system Ru–Os–Ir, in the order of occurrence osmium, ruthenium and iridium. The remainder consists of Pt–Fe alloys and species of PGE sulfides, arsenides, sulfarsenides, etc. The associated olivine and amphiboles are supermagnesian, and the chromian spinel has a high Cr# value. The observed enrichment in Ru, typical of an ophiolitic source, may be due to high-temperature hydrothermal equilibration and mobilization in the ophiolite, as is the enrichment in Mg and Cr. Low-temperature replacement of the alloys led to the development of laurite, sulfoarsenides and arsenides. Some placer grains in both suites reveal unusual phases of sulfo-arsenoantimonides of Ir–Rh, e.g. the unnamed species (Rh,Ir)SbS and (Cu,Ni)1+x(Ir,Rh)1–xSb, wherex= 0.2, and rhodian tolovkite, (Ir,Rh)SbS. Two series of natural solid-solutions appear to occur in the tolovkite-type phases. Among the oddities in the Rudnaya suite are globules of micrometric PGE sulfides, crystallites of platinum-group minerals, amphibole, and chalcopyrite bearing skeletal micrometric monosulfide-like compounds (Cu,Pt,Rh)S and (Pd,Cu)S1–x. Pockets of fluxed evolved melt seem to have persisted well below the solidus of the host Pt3Fe-type alloy.

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28

Smith, W. D., W. D. Maier, I. Bliss y L. Martin. "In Situ Multiple Sulfur Isotope and S/Se Composition of Magmatic Sulfide Occurrences in the Labrador Trough, Northern Quebec". Economic Geology 116, n.º 7 (1 de noviembre de 2021): 1669–86. http://dx.doi.org/10.5382/econgeo.4843.

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Abstract The interaction between mafic-ultramafic magma and crustal sulfide is considered a key process in the formation of magmatic Ni-Cu-platinum group element (PGE) sulfide deposits. Integrated S/Se and multiple sulfur isotope studies are the most robust in constraining the role of crustal sulfur during ore genesis. In the present study, we report the first integrated S/Se and multiple sulfur isotope study of magmatic sulfide occurrences in the Labrador Trough, namely, on the recently discovered Idefix PGE-Cu and Huckleberry Cu-Ni-(PGE) prospects. Whole-rock and in situ S/Se values (~810–3115) of magmatic sulfides and their host rocks are consistent with S loss during postmagmatic hydrothermal alteration, negating their use in interpreting the origin of S. Values of ∆33S ~0 indicate no record of the assimilation of Archaean sulfur. Disseminated (–0.5 to +2.5‰) and globular (3.0–4.5‰) sulfides at Idefix as well as globular sulfides (2.1–9.6‰) at Huckleberry have δ34S values greater than the accepted mantle range, suggesting that crustal S played a role in the formation of these sulfides. In contrast, disseminated and net-textured sulfides at Huckleberry have variable δ34S values (–4.6 to +3.2‰) that are mostly within the accepted mantle range, excluding one anomalous sample that records relatively higher δ34S values (11.9–15.0‰). It is proposed that sulfide melt segregated in response to the addition of small proportions of crustal S prior to the final emplacement of the host intrusions, i.e., in a feeder conduit or staging chamber. Isotopic exchange between the sulfide melt and silicate magma has diluted and, in places, eradicated a crustal δ34S signature.

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29

Begg, G. C., J. A. M. Hronsky, N. T. Arndt, W. L. Griffin, S. Y. O'Reilly y N. Hayward. "Lithospheric, Cratonic, and Geodynamic Setting of Ni-Cu-PGE Sulfide Deposits". Economic Geology 105, n.º 6 (1 de septiembre de 2010): 1057–70. http://dx.doi.org/10.2113/econgeo.105.6.1057.

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30

Ziramov, S., A. Dzunic y M. Urosevic. "Kevitsa Ni-Cu-PGE deposit, North Finland - A seismic case study". ASEG Extended Abstracts 2015, n.º 1 (diciembre de 2015): 1–4. http://dx.doi.org/10.1071/aseg2015ab122.

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31

Yakubchuk, Alexander y Anatoly Nikishin. "Noril?sk?Talnakh Cu?Ni?PGE deposits: a revised tectonic model". Mineralium Deposita 39, n.º 2 (1 de marzo de 2004): 125–42. http://dx.doi.org/10.1007/s00126-003-0373-0.

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32

Naldrett, A. J. "World-class Ni-Cu-PGE deposits: key factors in their genesis". Mineralium Deposita 34, n.º 3 (9 de marzo de 1999): 227–40. http://dx.doi.org/10.1007/s001260050200.

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33

Cao, Yonghua, Robert Linnen, David Good, Iain Samson y John McBride. "Igneous architecture and implications for diverse Cu-PGE mineralization styles in a conduit system: an example from the Area 41 Cu-PGE occurrence, Coldwell Complex, Canada". Mineralium Deposita 54, n.º 6 (25 de octubre de 2018): 867–84. http://dx.doi.org/10.1007/s00126-018-0844-y.

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34

Prichard, Hazel M., Saioa Suárez, Peter C. Fisher, Robert D. Knight y John S. Watson. "Placer platinum-group minerals in the Shetland ophiolite complex derived from anomalously enriched podiform chromitites". Mineralogical Magazine 82, n.º 3 (16 de abril de 2018): 491–514. http://dx.doi.org/10.1180/minmag.2017.081.099.

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ABSTRACTHighly anomalous platinum-group element (PGE) concentrations in the podiform chromitites at the Cliff and Harold's Grave localities in the Shetland ophiolite complex have been well documented previously. The focus of this study is alluvial platinum-group minerals (PGM) located in small streams that drain from the PGE-rich chromitites. The placer PGM assemblage at Cliff is dominated by Pt-arsenides (64%) and Pd-antimonides (17%), with less irarsite–hollingworthite (11%) and minor Pd-sulfides, Pt–Pd–Cu and Pt–Fe alloys and laurite. Gold also occurs with the PGM. Alluvial PGM have average sizes of 20 µm × 60 µm, with sperrylite the largest grain identified at 110 µm in diameter, matching the range reported for the primary PGM in the source rocks. The placer assemblage contains more Pt-bearing and less Pd-bearing PGM compared with the rocks. The more resistant sperrylite and irarsite–hollingworthite grains which are often euhedral become more rounded further downstream whereas the less resistant Pd-antimonides which are commonly subhedral may become striated and etched. Less stable phases such as Pt- and Pd-oxides and other Ni-Cu-bearing phases located in the rocks (i.e. Ru-pentlandite, PtCu, Pd–Cu alloy) are absent in the placer assemblage. Also the scarce PGM (PdHg, Rh- and Ir-Sb) and Os in the rocks are absent. At Harold's Grave only three alluvial PGM (laurite, Ir, Os) and Au were recovered reflecting the limited release of IPGM from chromite grains in the rocks. In this cold climate with high rainfall, where erosion dominates over weathering, the PGM appear to have been derived directly from the erosion of the adjacent PGE-rich source rocks and there is little evidence of in situ growth of any newly formed PGM. Only the presence of dendritic pure Au and Pd-, Cu-bearing Au covers on the surface of primary minerals may indicate some local reprecipitation of these metals in the surficial conditions.

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35

Lesher, C. M. "Up, down, or sideways: emplacement of magmatic Fe–Ni–Cu–PGE sulfide melts in large igneous provinces". Canadian Journal of Earth Sciences 56, n.º 7 (julio de 2019): 756–73. http://dx.doi.org/10.1139/cjes-2018-0177.

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The preferential localization of Fe–Ni–Cu–PGE sulfides within the horizontal components of dike–sill–lava flow complexes in large igneous provinces (LIPs) indicates that they were fluid dynamic traps for sulfide melts. Many authors have interpreted them to have collected sulfide droplets transported upwards, often from deeper “staging chambers”. Although fine (<1–2 cm) dilute (<10%–15%) suspensions of dense (∼4–5 g/cm3) sulfide melt can be transported in ascending magmas, there are several problems with upward-transport models for almost all LIP-related deposits: (1) S isotopic data are consistent with nearby crustal sources, (2) xenoliths appear to be derived from nearby rather than deeper crustal sources, (3) lateral sheet flow or sill facies of major deposits contain few if any sulfides, (4) except where there is evidence for a local S source, sulfides or chalcophile element enrichments rarely if ever occur in the volcanic components even where there is mineralization in the subvolcanic plumbing system, and (5) some lavas are mildly to strongly depleted in PGE >>> Cu > Ni > Co, indicating that unerupted sulfides sequestered PGEs at depth. Two potential solutions to this paradox are that (i) natural systems contained surfactants that lowered sulfide–silicate interfacial tensions, permitting sulfide melts to coalesce and settle more easily than predicted from theoretical/experimental studies of artificial/analog systems, and (or) (ii) sulfides existed not as uniformly dispersed droplets, as normally assumed, but as fluid-dynamically coherent pseudoslugs or pseudolayers that were large and dense enough that they could not be transported upwards. Regardless of the ultimate explanation, it seems likely that most high-grade Ni–Cu–PGE sulfide deposits in LIPs formed at or above the same stratigraphic levels as they are found.

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36

Ding, Xin, Edward M. Ripley y Chusi Li. "PGE geochemistry of the Eagle Ni–Cu–(PGE) deposit, Upper Michigan: constraints on ore genesis in a dynamic magma conduit". Mineralium Deposita 47, n.º 1-2 (6 de mayo de 2011): 89–104. http://dx.doi.org/10.1007/s00126-011-0350-y.

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37

Kamenetsky, Vadim S. y Michael Zelenski. "Origin of noble-metal nuggets in sulfide-saturated arc magmas: A case study of olivine-hosted sulfide melt inclusions from the Tolbachik volcano (Kamchatka, Russia)". Geology 48, n.º 6 (13 de abril de 2020): 620–24. http://dx.doi.org/10.1130/g47086.1.

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Abstract Minerals that contain platinum-group elements (PGEs) and occur in some magmatic Cu-Ni sulfide deposits have been ascribed to crystallization from an originally PGE-rich sulfide liquid. The occurrence of PGE-bearing minerals (PGMs) in some sulfide-undersaturated primitive melts has been envisaged and recently reported, whereas direct crystallization of PGMs in sulfide-saturated silicate magmas is seemingly hindered by strong partitioning of PGE into immiscible sulfide melts. In this study, we discovered abundant nanoparticles containing noble metals in association with sulfide melt inclusions entrapped inside primitive olivine phenocrysts (Fo85–92) from the recent basaltic magma of the Tolbachik volcano (Kamchatka arc, Russia). These nuggets occur in swarms on the surface of the sulfide globules and are represented by native metals, sulfides, and alloys of Pd, Pt, Au, Pb, and Bi. The nuggets on different globules can be either Pd- or Pt-rich nuggets, and the compositions are highly variable, even among adjacent nuggets. We argue that the diffusive supply of Pd from the external nuggets can be responsible for significant uptake of Pd (up to 2 wt%) in the sulfide melt. We consider direct crystallization of PGMs in a primitive basaltic melt undergoing sulfide unmixing, and possibly sulfide breakdown due to oxidation, as another mechanism additional to their “classic” origin from the PGE-rich sulfide melt in response to solidification.

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38

Gervilla, Fernando, Alejandro Sáncnez-Anguita, Rogelio D. Acevedo, Purificación Fenoll Hach-Ali y Andres Paniagua. "Platinum-group element sulpharsenides and Pd bismuthotellurides in the metamorphosed Ni-Cu deposit at Las Aguilas (Province of San Luis, Argentina)". Mineralogical Magazine 61, n.º 409 (diciembre de 1997): 861–77. http://dx.doi.org/10.1180/minmag.1997.061.409.09.

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AbstractThe Las Aguilas Ni-Cu-PGE deposit is associated with a sequence of basic-ultrabasic rocks made up of dunite, harzurgite, norite and amphibolite. These igneous (partially metamorphosed) rocks, and their host granulites, gneisses and migmatites of probable Precambrian age, are highly folded. The sulphide ore, consisting of pyrrhotite, pentlandite and chalcopyrite, occurs in the cores of both antiform and synform structures, within dunite, harzburgite and mainly along shear zones in bronzitite, replacing small mylonitic subgrains. The platinum-group mineral assemblage is dominated by Pd bismuthotellurides (Pt-free merenskyite, palladian bismuthian melonite and michenerite), with minor sperrylite, and PGE-sulpharsenides. The latter often occur as single, zoned crystals frequently showing cores of irarsite; outside these are concentric zones of cobaltian hollingworthite, rhodian nickelian cobaltite and Fe-rich nickelian cobaltite.Mineralogical, textural and chemical evidence indicate that the sperrylite and platinum-group element sulpharsenides were formed during a primary magmatic event associated with the fractionation of a basaltic melt, which was contaminated by the assimilation of metamorphic crustal rocks. PGE sulpharsenides crystallized from As-bearing, residual magmatic liquids that collected PGE and segregated after the crystallization of the monosulfide solid solution. During high-grade metamorphism, sulpharsenides were remobilized as solid crystals in the liquated sulfides suffering partial dissolution and fracturing. On the other hand, there is no evidence of a primary concentration of Pd-bismuthotelluride minerals, and their present spatial distribution is only the consequence of their formation under high- to medium-grade metamorphism, down to temperatures of below 500°C. Pd bismuthotellurides crystallize even in fractures of sulpharsenides, attached to the boundaries of highly dissolved sulpharsenide crystals, and intergrown with molybdenite.

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39

Larson, Michelle S., William E. Stone, William A. Morris y James H. Crocket. "Magnetic signature of magnetite‐enriched rocks hosting platinum‐group element mineralization within the Archean Boston Creek Flow, Ontario". GEOPHYSICS 63, n.º 2 (marzo de 1998): 440–45. http://dx.doi.org/10.1190/1.1444344.

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Ground‐based magnetometer surveys detect high‐positive magnetic anomalies (up to 72 000 nT) which coincide with the location of subeconomic, magnetite‐associated platinum‐group element (PGE) mineralization within the Boston Creek Flow iron‐rich basalt, Archean Abitibi Greenstone Belt, Ontario. The magnetic anomalies confirm the presence of magnetite‐enriched zones (up to 20 modal%), and reveal that they are ovoid in shape, up to 10 m in size, and along strike from each other in the central gabbro‐diorite layer. Geological and geochemical surveys and mineralogical studies indicate that these zones host smaller zones of disseminated chalcopyrite + pyrite, some of which, in turn, host platinum‐group minerals (PGM) and are enriched in PGE and related metals (whole‐rock [Formula: see text], Ag = 1300 ppb, Cu = 0.3%, V = 0.1%, Ni = 0.05%, Ti = 2.5%, and Fe = 25%). The coincidence of the high‐positive magnetic anomalies with the location of PGE mineralization, points to ground‐based magnetometer surveys as a valuable exploration tool for magnetite‐associated PGE ore deposits. The distribution of the residual magnetic field anomalies indicate that such surveys are especially useful in: (1) identifying rock types and mapping their distribution in areas of limited outcrop exposure; (2) locating magnetite‐enriched gabbroic rock bodies, even in close proximity to serpentinized olivine cumulate rocks; and (3) delineating the detailed geometry of magnetite‐enriched rocks that may carry significant amounts of PGE and PGMs. Exploration strategies should be designed to use ground‐based geophysical surveys, in conjunction with geological and geochemical surveys, to locate and delineate the geometry of magnetite‐enriched zones within thick, differentiated mafic‐ultramafic volcanic flows and plutonic bodies.

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40

Shahabi Far, Maryam, Iain M. Samson, Joel E. Gagnon, David J. Good, Robert L. Linnen y Doreen Ames. "Evolution of a Conduit System at the Marathon PGE–Cu Deposit: Insights from Silicate Mineral Textures and Chemistry". Journal of Petrology 60, n.º 7 (1 de julio de 2019): 1427–60. http://dx.doi.org/10.1093/petrology/egz035.

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Abstract The Marathon platinum group element (PGE)–Cu deposit is hosted by the Two Duck Lake Gabbro of the Mesoproterozoic Coldwell Complex, Canada, and comprises three zones of mineralization, which have different textural, mineralogical and geochemical characteristics. The Footwall Zone occurs at the base of the Two Duck Lake Gabbro, at the contact with the Archean country rocks. The Main Zone occurs within the Two Duck Lake Gabbro, above the Footwall Zone. The W Horizon is an extraordinarily PGE-enriched zone that is characterized by very low Cu/Pd values, less pyrrhotite, and appreciably more bornite than the Footwall and Main zones. It occurs above Main Zone-equivalent mineralization in the southern half of the Two Duck Lake intrusion. Silicate mineral textures and chemistry reveal that the Marathon deposit formed in a dynamic magma conduit system with a complex magma evolution history. The deposit developed into three zones as a result of the multiple pulses of compositionally different magmas. Plagioclase commonly shows resorption surfaces with overgrowths and the anorthite content and concentrations of trace elements such as Fe, Sr, Ba, and rare earth elements in plagioclase change significantly across these surfaces. In rocks that contain sulfide minerals, plagioclase crystals have been partly resorbed and the resorbed rims are Ca-enriched and intergrown with sulfide mineral inclusions. These rims contain higher base-metal and sulfur contents and are light rare earth element-enriched compared with the primary plagioclase. These characteristics indicate input of a separate sulfide-enriched melt with a different composition compared with that from which the primary plagioclase crystallized. Additional evidence for the involvement of slightly different magmas during evolution of the three mineralized zones is derived from variations in pyroxene chemistry (e.g. higher Fe, lower Mg, V, and Sc) between the Footwall Zone and the other two zones and the absence of inverted pigeonite from the W Horizon. The PGE enrichment occurred at depth prior to intrusion and late-stage PGE-rich sulfide-bearing magmas intruded and formed the W Horizon. Therefore, the W Horizon is a zone of mineralization that formed late in the evolution of the Two Duck Lake Gabbro.

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41

Fiorentini, M. L., S. W. Beresford y M. E. Barley. "Controls on the genesis and emplacement of komatiite-hosted Ni–Cu–PGE-sulphides at Albion Downs (Agnew-Wiluna Belt, Western Australia): a case study on the development of PGE lithogeochemical vectors to Ni–Cu–PGE-sulphide deposits". Applied Earth Science 116, n.º 4 (diciembre de 2007): 152–66. http://dx.doi.org/10.1179/174327507x207500.

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42

Barkov, A. Y., J. H. G. Laflamme, L. J. Cabri y R. F. Martin. "PLATINUM-GROUP MINERALS FROM THE WELLGREEN Ni Cu PGE DEPOSIT, YUKON, CANADA". Canadian Mineralogist 40, n.º 2 (1 de abril de 2002): 651–69. http://dx.doi.org/10.2113/gscanmin.40.2.651.

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43

Li, C., W. D. Maier y S. A. de Waal. "Magmatic Ni-Cu versus PGE deposits: Contrasting genetic controls and exploration implications". South African Journal of Geology 104, n.º 4 (1 de diciembre de 2001): 309–18. http://dx.doi.org/10.2113/gssajg.104.4.309.

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44

Barnes, Stephen J., Alexander R. Cruden, Nicholas Arndt y Benoit M. Saumur. "The mineral system approach applied to magmatic Ni–Cu–PGE sulphide deposits". Ore Geology Reviews 76 (julio de 2016): 296–316. http://dx.doi.org/10.1016/j.oregeorev.2015.06.012.

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45

Fiorentini, M. L., S. W. Beresford, N. Rosengren, M. E. Barley y T. C. McCuaig. "Contrasting komatiite belts, associated Ni–Cu–(PGE) deposit styles and assimilation histories". Australian Journal of Earth Sciences 57, n.º 5 (julio de 2010): 543–66. http://dx.doi.org/10.1080/08120099.2010.492911.

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46

Hulbert, L. y W. Stone. "Eastern Wrangellia – A New Ni-Cu-PGE Metallogenic Terrane in North America". ASEG Extended Abstracts 2006, n.º 1 (diciembre de 2006): 1–7. http://dx.doi.org/10.1071/aseg2006ab070.

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47

Boutroy, Emilie, Sarah A. S. Dare, Georges Beaudoin, Sarah-Jane Barnes y Peter C. Lightfoot. "Magnetite composition in Ni-Cu-PGE deposits worldwide: application to mineral exploration". Journal of Geochemical Exploration 145 (octubre de 2014): 64–81. http://dx.doi.org/10.1016/j.gexplo.2014.05.010.

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48

Le Vaillant, Margaux, Marco L. Fiorentini y Stephen J. Barnes. "Review of lithogeochemical exploration tools for komatiite-hosted Ni-Cu-(PGE) deposits". Journal of Geochemical Exploration 168 (septiembre de 2016): 1–19. http://dx.doi.org/10.1016/j.gexplo.2016.05.010.

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Lawley, Christopher J. M., Victoria Tschirhart, Jennifer W. Smith, Sally J. Pehrsson, Ernst M. Schetselaar, Andrew J. Schaeffer, Michel G. Houlé y Bruce M. Eglington. "Prospectivity modelling of Canadian magmatic Ni (±Cu ± Co ± PGE) sulphide mineral systems". Ore Geology Reviews 132 (mayo de 2021): 103985. http://dx.doi.org/10.1016/j.oregeorev.2021.103985.

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McDonald, Iain, R. E. (Jock) Harmer, David A. Holwell, Hannah S. R. Hughes y Adrian J. Boyce. "Cu-Ni-PGE mineralisation at the Aurora Project and potential for a new PGE province in the Northern Bushveld Main Zone". Ore Geology Reviews 80 (enero de 2017): 1135–59. http://dx.doi.org/10.1016/j.oregeorev.2016.09.016.

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