Title: A preliminary report on amphibolite-facies, disseminated-replacement-style mineralization at the Madsen gold mine, Red Lake, Ontario
Abstract:Madsen is a disseminated stratabound gold deposit of replacement style located at the deformed unconformity between the Balmer and Confederation assemblages. The deposit comprises two main ore horizon...Madsen is a disseminated stratabound gold deposit of replacement style located at the deformed unconformity between the Balmer and Confederation assemblages. The deposit comprises two main ore horizons (Austin and McVeigh), hosted by altered mafic volcaniclastic rocks and by (massive and pillowed) basalt flows of the Balmer assemblage metamorphosed at amphibolite grade. A banded-laminated inner core of alteration hosts the ore and is surrounded by an aluminum-rich outer alteration. D1 is characterized by a bedding-parallel foliation and D2, the main phase, is characterized by an S2 foliation, local sinistral shearing, and F2 folds. The alteration and mineralization have been deformed by the D2 structures. The deposit is early or pre-D2 and was formed between 2744 ± 1 Ma, the age of a quartz-feldspar porphyry, and 2699 ± 4, the age of a post-ore dyke. Madsen shares some features analogous with higher temperature (400 to 600°C) gold deposits as well as gold skarns hosted by mafic rocks.Read More
Publication Year: 2000
Publication Date: 2000-01-01
Language: en
Type: report
Indexed In: ['crossref']
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Cited By Count: 11
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