Résumés
Abstract
Gold occurs mainly In laminated bedding-parallel quartz veins in the Goldenvllle Formation metawacke-slate sequence. The bedding-parallel veins formed by hydraulic fracturing before the beds were folded. Subsequently, during development of the folds, en echelon quartz veins formed on the fold limbs, and perhaps in the latest stage of folding, saddle reef veins formed along fold hinges. All these vein types are locally auriferous, but gold was first deposited during formation of the bedding-parallel veins. Absence of any through-going system of "feeder" veins as well as the formation of hydraulic fractures indicate that the rocks were not permeable during vein formation, and the quartz and gold were derived locally from the host strata.
RESUME
L'or present dans la suite metawacke-schiste de la Formation Goldenvllle est localise principalement dans des veines de quartz laminles et parallels 3 la stratification. Ces veines parallels i stratification furent formees par fracture hydraulique avsnt le plissement des lits. Par la suite, pendant l'amplification des plls, des veines de quartz en echelon furent formies sur les flancs de plis et peut-fitre, pendant la phase finale de plisseaent, des veines en "glte de selle" se formerent i la charniere de plis- Tous ces types de veines sont aurif£res par endroit mais l'apport initial de l'or date de la formation des veines parallees i la stratification. L'absence de syste'me de veines nourricieree sins! que la formation de fractures hydrauliques indiquent que les roches n'£talent pas permgables 3 l'gpoque de formation de veine et que le quartz et l'or sont de provenance locale.
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