SOME PETROGRAPHIC AND GEOCHEMICAL ASPECTS OF ARCHEAN VOLCANIC FORMATION OF MALARTIC IN ABITIBI (QUEBEC, CANADA)

The Archean metavolcanic formations of the Malaric Group in Abitibi, northwestern Quebec (Canada), are several kilometers thick and made up of lavas and pyroclastic rocks, a large part of which are of submarine origin with pillows and hyaloclastites. The regional metamorphism of greenschist and locally amphibolite-almandine facies, has destroyed the magmatic paragenesis; on the other hand, the original textures and structures are generally well preserved. A geochemical study of major elements was carried out on 67 well chosen fine-grained lavas. Conclusions of the study are summarized.