REE and background Au/Ag evidence concerning the origin of hydrothermal fluids in the Cape Ray electrum deposits, southwestern Newfoundland

Abstract The Cape Ray Fault Zone of southwestern Newfoundland contains two notable electrum/base metal sulphide quartz vein lode occurrences hosted by two contrasting lithological units, viz. a graphite schist horizon and a granite. The two occurrences, although in proximity, are not in direct contact, but, based on geochronological, geochemical and isotopic evidence, they were apparently deposited from hydrothermal fluids generated as a vapour phase from the magmatic progenitor of the Windowglass Hill granite.
This paper provides further evidence, from REE and background Au andAg data, for the magmatic origin of the hydro-thermal fluids. Wall rocks to the electrum-bearing quartz veins in both the schists and granite have experienced a LREE depletion probably due to leaching by Cl--bearing solutions. Gold and silver contents are typically low in all rock types but there is a slight elevation in gold concentrations in those units in contact with the Windowglass Hill granite. The granite also has the relatively highest gold and silver contents of any unit in the region.
Keywords: Gold mineralization, Rare earth elements, Cape Ray, Electrum deposits, Hydrothermal fluids, Gold, Silver, Granites.
Full Access to Technical Paper
PDF version for $20.00
Search
Sort By:  Relevance
Showing results 1 - 4
Text
Summary: A low-grade concentrate from the Crevier Township, Quebec, containing 1.8% Ta2O5 and 13.7% Nb2O5 was reduced with carbon at 1600"C, and niobium and tantalum were selectively absorbed in liquid iron. To slag off the zirconia-rich gangue, some silica and lime were added as flux. Metallic iron was added in such a way that the combined contents of TaC and NbC did not exceed 20% in the ferroalloy. Up to 95% of the niobium, and up to 80% of the tantalum contained in the concentrate were...
Publication: CIM Bulletin
Author(s): M. NAGAMORI, A.J. PLUMPTON
Keywords: Pyrometallurgy, Smelting, Leaching, Calcination, Niobium, Tantalum, Ferroalloys.
Issue: 874
Volume: 78
Year: 1985
Text
Summary: A trondhjemite stock intrudes a volcanic sequence that has massive sulphide lenses and that is metamorphosed to the green-schist fades at Gutcher Lake, 25 km north of Wawa, Ontario. The stock is 4 km2 in plan and is partly enveloped by an aureole of chlorite-epidote-amphibole hornfels up to 1 km wide. Within this contact aureole, biotite is partly pseudomorphosed by chlorite; epidote and hornblende are mottled by chlorite, calcite, plus quartz; albite has 0% An to 8% An; and hornblende...
Publication: CIM Bulletin
Author(s): P.A. STUDEMEISTER
Keywords: Gold exploration, Gold-bearing veins, Regional metamorphism, Retrograde metamorphism, Felsic intrusions, Greenstone belts, Mineral alteration.
Issue: 874
Volume: 78
Year: 1985
Text
Summary: The recent opening of Muscocho's gold mine at Montauban, as well as the discovery of several new copper-gold showings of a similar nature near the confluence of the Saguenay and St. Lawrence has revealed the existence of a new metallogenic gold province which is located within supercrustal units of Helikian age within the Grenville Province. Three metalliferous belts have been identified, each one of which is related to a series of SW-NE trending faults. The first is located in southeastern...
Publication: CIM Bulletin
Author(s): MICHEL GAUTHIER, GAETAN MORIN, PIERRE MARCOUX
Keywords: Gold mineralizalion, Gold, Melallogeny, Grenville Province, Monlauban region.
Issue: 874
Volume: 78
Year: 1985
Text
Summary: Kidd Creek is a large volcanogenic base metal sulphide deposit, located near the west end of the Abitibi greenstone belt, 27 km north of Timmins, Ontario. The rhyolite geology is characterized by a NNE-striking and steeply east-dipping package of rhyolite volcaniclastics upon which has been imposed a strong ESE-striking and north-dipping structural fabric. Massive rhyolite units with grey-black, chloritic cores and yellow, sericitic margins intrude as dykes into the stratigraphic footwall and...
Publication: CIM Bulletin
Author(s): P.P. GOAD
Keywords: Economic geology, Kidd Creek Mine, Volcanogenic deposits, Base metal sulphide deposits, Rhyolite geology, Massive rhyolites, Rhyolite volcaniclastic, Crackle-brecciated rhyolites, Stringer sulphide zone, Hydrothermal alteration, Mature alteration, Immature alteration, Hydraulic fracturing, Evolution felsic pile, Exploration.
Issue: 874
Volume: 78
Year: 1985
Powered by Coveo Enterprise Search