A pillowed mafic metavolcanic from an Archean volcanic belt near Wawa, Ontario contains over 16% MgO and has a CaO/Al2O3 ratio of 1.5. It is chemically similar to the basaltic komatiites described from the Archean of South Africa. Because komatiites are related chemically and stratigraphically to Archean basalt–dacite–rhyolite suites, we propose that all these volcanic types should be considered genetically in terms of an Archean volcanic or island arc tectonic regime.

You do not currently have access to this article.