EESA06H3 Lecture Notes - Lecture 10: Acasta Gneiss, Gunflint Chert, Canadian Pacific Railway
20 Apr 2012
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All the continents are constructed in a similar fashion. Slide 1: craton is core of north american read properly. Martime is added when pangea is forming. Western canada added after pangea breaks up. Mostly sedimentary rocks added on eastern and western canada. Blue > is apalasian belt red > craton. Zircons [2. 7bys] > used for uranium lead dating > can"t say much about geological area w/o knowing age of age: new method. Zircon > analyze it to know how much lead is there > help determine age. Acasta gneiss > 4bya oldest crust found in canada. We"re only dating since when it was a gneiss > was a rock before that too. Detrital > having been derived from something else. Zircons originate in igneous rock then get weather > released in water become metaphoric rock > gneiss. Oldest rock in the middle: old rocks are embedded in the interior of continents.
