Title: An Archean oceanic felsic dyke swarm in a nascent arc: the Hunter Mine Group, Abitibi Greenstone Belt, Canada
Abstract: Abstract The 2730-Ma-old Hunter Mine Group (HMG), a dominantly felsic subaqueous volcanic sequence, was formed during early arc construction in the Abitibi greenstone belt (Quebec, Canada). The western part of the HMG contains a felsic dyke swarm up to 1.5 km wide and traceable up-section for 2.5 km. Five distinct generations were identified: (1) aphanitic to feldspar-phyric dykes; (2) quartz-feldspar-phyric dykes with Nd values suggest that an older sialic substrate was not involved in their genesis. We infer that the felsic rocks were generated by melting of mafic oceanic crust. The swarm was emplaced during nascent oceanic island-arc development and was related to rifting of the arc. The conformably overlying MORB-like basalts and basaltic komatiites of the Stoughton-Roquemaure Group used the same conduits and further indicate splitting of the arc. HMG and associated parts of the Abitibi greenstone belts bear a strong resemblance to modern rifted intraoceanic arcs of the western Pacific.
Publication Year: 1996
Publication Date: 1996-07-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 21
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