Paleomagnetism of Sediment Cores from Cedarburg Bog,Wisconsin, and a Comparison with Cores from Lake Michigan

Four 10-m sediment cores from the Cedarburg Bog, Wisconsin, were collected for paleomagnetic measurement and carbon-14 dating. The paleomagnetic records for these cores are self consistent, with the intensity record affording the best correlation. These results are compared with sediment cores from Lake Michigan. The two sets of cores are unmistakably correlatable on the basis of intensity. The inclination correlation also shows common long and short wavelength features.On the basis of this correlation, we date certain member boundaries of the Lake Michigan Formation as follows: Waukegan–Lake Forest, 5,500 years B.P.; Lake Forest–Winnetka, 7,800 years B.P.; and Winnetka–Sheboygan, 9,700 years B.P.