Archean

Définition et enjeux

Congrès géologique international,  Congrès géologique international… (1893)

“ Even if the position be true, the school that believe
in the igneous origin of the Archean would still have a large mass of rocks for the Archean by shifting their grounds so as to include in it all the material which, in the slow process of inward crystallization, has now reached the surface of the earth, not by intrusion in the rocks above, but by erosion. This position would, however, be controverted j by those who regard such rocks as plutonic and belonging to the age of their equivalent sedimentaries.
”
Source : Gallica

Congrès géologique international,  Congrès géologique international… (1891)

“ Erti ptives, of course, should be set aside. They may be similar in the Archean and Post-Archean formations. Outside of unmistakable eruptives my own experience-and my own experience leads me wholly that way-is that while there are rocks which have been altered and have acquired a semi-crystalline character, e.g., some mica-schists and quartzites, among the Post-Archean formations, counting now the Huronian as Post-Archean—there are Some true Archean rocks, chiefly the true banded gneiss, which do not occur above the Archean. ”
Source : Gallica

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