Annual report of the United States Geological Survey to the Secretary of the Interior . TURNER] SCHISTOSITY AND BEDDING. 555 Professor Lawson writes (p. 142): An important discovery lias lieen made in the mapping of the relative distribu-tion of the upper and lower Archean, whereby it appears that the latter, consistingof Laurentian gneiss and granite, occurs in large isolated central areas more or lesscompletely surrounded by the schists of the upper Archean (now called Algonkian),the encircling belts anastomosing and forming a continuous meshwork. W i ii fJ/t//:.

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