01213nas a2200169 4500008004100000245004500041210004500086300001200131490000600143520073700149653001200886100002200898700001600920700001900936700001500955856007300970 1965 eng d00aArchean Volcanism in the Canadian Shield0 aArchean Volcanism in the Canadian Shield a161-1750 v13 a
Chemical compositions of Archaean volcanic rocks in the Superior province of the Canadian shield have been determined from 261 new analyses from 10 volcanic belts. The analyses are compared with those of the various volcanic associations. This comparison shows that the volcanic rocks of all belts belong to the basalt andesite rhyolite association typical of continental orogenic belts or island are systems. A primitive continent with continental rocks must, therefore, have existed in early Archaean time.The Keewatin lava sequences in the various belts are remnants of a great volcanic sequence that covered the southern half of the Superior province of the Canadian shield.