North-Central Section - 38th Annual Meeting (April 1–2, 2004)

Paper No. 21
Presentation Time: 8:00 AM-12:00 PM

PRECAMBRIAN VALLEYS AND RIDGES IN THE CANADIAN SHIELD IN SOUTHERN CLARK COUNTY, WISCONSIN


MILLER, Jolene K., St. Cloud, MN 56301, jolenekaymiller@yahoo.com

An ancient erosion surface is carved in Archean augen gneiss, granite gneiss, and granite. This ancient erosion surface is exposed along the Black River channel in southern Clark County, Wisconsin. It forms a narrow, north-south, sub-surface ridge. The geologic factors (lithology, structure & tectonics) controlling the presence of this ridge are being investigated. It is probable that resistance to weathering and erosion of some lithologies have controlled the development of stream valleys east and west of the ridge.