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TitreMineralogical, sulphur, and lead isotopic study of the Lemarchant Zn-Pb-Cu-Ag-Au-VMS deposit: implications for precious-metal enrichment processes in the VMS environment
TéléchargerTéléchargement (publication entière)
AuteurGill, S B; Piercey, S J; Layton-Matthews, D; Layne, G D; Piercey, G
SourceTargeted Geoscience Initiative 4: Contributions to the understanding of volcanogenic massive sulphide deposit genesis and exploration methods development; par Peter, J M (éd.); Mercier-Langevin, P (éd.); Commission géologique du Canada, Dossier public 7853, 2015 p. 183-195, https://doi.org/10.4095/296552
LiensCanadian Database of Geochemical Surveys, downloadable files
LiensBanque de données de levés géochimiques du Canada, fichiers téléchargeables
Année2015
ÉditeurRessources naturelles Canada
Documentdossier public
Lang.anglais
DOIhttps://doi.org/10.4095/296552
Mediaen ligne; numérique
Référence reliéeCette publication est contenue dans Peter, J M; Mercier-Langevin, P; (2015). Targeted Geoscience Initiative 4: Contributions to the understanding of volcanogenic massive sulphide deposit genesis and exploration methods development, Commission géologique du Canada, Dossier public 7853
Formatspdf
ProvinceTerre-Neuve-et-Labrador
SNRC12A/10
Lat/Long OENS -56.7500 -56.5833 48.6667 48.5000
SujetsArchéen; gîtes volcanogènes; gîtes sulfureux; altération; métamorphisme; assemblages de minéraux; minéralisation; directives d'exploration; roches volcaniques; gisements minéraux; or; gîtes minéralogiques; zinc; plomb; cuivre; argent; sulfures; barytine; sphalérite; pyrite; chalcopyrite; bornite; tétrahédrite; tennantite; stroméyérite; galène; faciès; gisements stratiformes; isotopes; rapports des isotopes de plomb; rapports des isotopes de soufre; Zone de Dunnage ; Ligne de Red Indian ; géologie économique; minéralogie; Précambrien; Paléozoïque; Cambrien
Illustrationslocation maps; photomicrographs; tables; histograms; cross-sections
ProgrammeÉtude des gîtes de sulfures massifs volcaniques, Initiative géoscientifique ciblée (IGC-4)
Diffusé2015 06 11
Résumé(disponible en anglais seulement)
The Lemarchant deposit is a Cambrian volcanogenic massive sulphide (VMS) deposit located in the Central Mobile Belt of the Newfoundland Appalachians. Unlike other polymetallic VMS deposits in the bimodal felsic Tally Pond group, Lemarchant is enriched in precious metals. The deposit is composed of contrasting styles of sulphide mineralization, and formed in three discrete stages: Stage 1: barite-rich, low-temperature (<250oC) VMS mineralization; Stage 2: 150 to 250oC intermediate- to high-sulphidation epithermal-style mineralization; and Stage 3: polymetallic, high-temperature (>300oC) VMS mineralization. Sulphur isotopes suggest that S is derived from three sources: thermochemically reduced seawater sulphate, leached igneous basement rock, and magmatic SO2. Lead isotopes indicate that Pb is primarily derived from evolved crustal material, with some input from juvenile volcanic rock (i.e. arc-rift). Precious metals associated with epithermal-style mineralization are consistent with a magmatic contribution to the hydrothermal fluid. Precious metals were precipitated from intermittently boiled fluids, at relatively shallow (<1500 m) water depth.
GEOSCAN ID296552