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Granite is found throughout northern and central Minnesota. It varies
in age from 2.6 billion years in the Minnesota River Valley and northern
Minnesota to about 1.7 billion years near St. Cloud. Minnesota granites
are composed predominantly of the minerals feldspar, quartz, mica, and
hornblende. These rocks formed deep below the surface in the roots of
major mountain ranges. These once deeply buried rocks are now exposed
at or near the surface due to uplift and erosion. Granite is quarried
for use as building stone and monuments. You can find outcrops of granite
in Stearns, Pine, and Mille Lacs counties, and also in places in northeastern
Minnesota, including the Boundary Waters Canoe Area. |
