Relation of fluid inclusion geochemistry to wallrock alteration and lithogeochemical zonation at the Hollinger-Mclntyre gold deposit, Timmins, Ontario, Canada

Abstract Zonation patterns are well developed in the mafic meta-volcanic rocks that host epigenetic quartz-carbonate-gold vein mineralization at the Hollinger-Mclntyre deposit. Carbonate alteration assemblages are strongly zoned about mineralization. Proceeding inward from background greenschist fades rocks to alteration envelopes enclosing individual veins, the following assemblages are observed: Assemblage I—quartz-albite-chlorite-epidote-actinolite-(calcite) Assemblage II—quartz-albite-chlorite-calcite-epidote Assemblage HI—quartz-ankerite-sericite-(chlorite-calcite) Assemblage IV—quartz-albite-ankerite-sericite
Lithogeochemical zoning is equally well developed as variations in whole-rock abundances of As, Au, Ba, Rb, andSb. As and Ba form the most useful zonation patterns, outlining individual ore zones as well as broader trends of mineralization. Gas chromatographic analyses of fluid inclusions in the quartz-carbonate veins indicate that the mineralizing fluid was an H2O-CO2 mixture. Locally, CH4-rich fluid inclusions are associated with graphitic and/or carbonaceous wallrocks. Fluid inclusions in ore-bearing veins have higher CO2 contents than those in non-ore veins. Extensive sampling and analyses of veins from the area surrounding the deposit reveals a well developed zonation of CO2 contents about the main zone of mineralization. Low CO2 levels (1-2 mole%) in veins are peripheral to the deposit and increase to over 12 mole% in mineralized zones.
The observed zoning of the carbonate alteration assemblages is a result of the addition ofCO2 to the wallrock, which is consistent with the zoning of CO2 in the fluid inclusions. The zoning patterns delineated in this study are useful in exploration both on a deposit scale and on the scale of individual ore zones.
Keywords: Mineral exploration, Fluid inclusion, Geochemistry, Wallrock alteration, Gold mineralization, Zoning patterns, Trace elements, Economic geology
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Summary: A helicopter-borne geophysical survey was flown in 1978 over selected areas on Kyushu Island, Japan. The principal sensors were a moving source electro-magnetic system and a magnetometer. Maps of apparent resistivity were generated from the EM data. Based on the resistivity signature of known deposits within the survey areas, targets were selected for ground follow-up. Drilling of one such target in late 1980 resulted in the discovery of a gold deposit from which full production will begin in...
Publication: CIM Bulletin
Author(s): IAN M. JOHNSON, MINORU FUJITA
Keywords: Mineral exploration, Electromagnetic survey, Drilling, Gold deposits, Geophysics, Hishikari gold deposits.
Issue: 876
Volume: 78
Year: 1985
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Summary: The world's first zinc pressure leaching plant at Cominco's Trail operations started production in 1981. Sullivan zinc concentrate is leached at the rate of 190 tpd in a four-compartment autoclave at elevated temperatures and oxygen pressures to produce a zinc sulphate solution and elemental sulphur. Zinc extraction exceeds 98% and sulphide to elemental sulphur conversion exceeds 95%.
The sulphur is recovered from the discharged slurry in the underflow of a hydrocyclone, and is upgraded as a...
Publication: CIM Bulletin
Author(s): M.T. MARTIN, W.A. JANKOLA
Keywords: Extractive metallurgy, Zinc pressure leaching plant, Zinc, Pressure leaching, Sulphur recovery, Flotation.
Issue: 876
Volume: 78
Year: 1985
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Summary: A test surface Pulse EM(PEM) survey over a plunging massive sulphide lens, located in the Snow Lake area of Manitoba, has shown that it is possible to detect the body to a depth of 300 metres. Another surface survey in the Athabasca basin of Saskatchewan, clearly outlined a large, basement graphitic zone below 450 metres of sandstone cover. Deep detection of these conductive bodies was achieved by energizing large volumes of ground with a strong transmitted EM field. Such large fields also...
Publication: CIM Bulletin
Author(s): J. DUNCAN CRONE
Keywords: Mineral exploration, Pulse EM survey, Ore deposits, Massive sulphides, Drilling, Geophysics, Boreholes.
Issue: 876
Volume: 78
Year: 1985
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Summary: Brogan coal containing mean averages of 6,93% w/w total sulphur (1.1% sulphate sulphur, 1.6% organic sulphur and 4.24% pyritic sulphur) and 16.34% mineral ash was used as the test coal in these studies.
Shake-culture leaching studies on seven size fractions of the coal, ranging in size from 0.045 mm to 1.7 mm, showed that the rate of pyrite leaching was inversely proportional to the particle size. As the use of continuous stirred tank reactors would be uneconomical for the reclamation of...
Publication: CIM Bulletin
Author(s): R.G.L McCREADY, MARCOS ZENTILLI
Keywords: Coal reclamation, Waste dumps, Bacterial leaching, Acid mine drainage.
Issue: 876
Volume: 78
Year: 1985
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Summary: The Gondor Zn-Ag-Pb-Cu deposit is a stratabound massive sulphide lens occurring within Archean volcanidastic rocks of the Yellowknife Supergroup. The deposit is located in the west-central portion of the Slave Structural Province, approximately 350 km north of Yellowknife. Initial diamond drilling at Gondor has outlined a steeply-dipping, L-shaped, folded, massive sulphide body, which may be traced over a strike length of approximately 800 m, and to a depth of 350 m. True widths of up to 40 m...
Publication: CIM Bulletin
Author(s): D.S. BUBAR, J.B. HESLOP
Keywords: Mineral exploration, Geology, Massive sulphide deposits, Gondor deposit, Slave Province, Drilling, Wallrock alteration, Stratigraphy.
Issue: 876
Volume: 78
Year: 1985
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