||Sedimentation Rates and Depositional Processes in Lake Superior from 210Pb Geochronology.
Evans, J. E. ;
Johnson, T. C. ;
Alexander, Jr., E. C. ;
Lively, R. S. ;
Eisenreich, S. J. ;
||Minnesota Univ., Minneapolis. Dept. of Geology and Geophysics. ;Minnesota Univ., Minneapolis. Limnological Research Center. ;Minnesota Geological Survey, St. Paul.;Environmental Research Lab.-Duluth, MN.;National Science Foundation, Washington, DC.
||CONTRIB-1038; EPA-R-806084 ;NSF-OCE78-08166; EPA-600/J-81-664;
Lake Superior ;
Rates(Per time) ;
Lead isotopes ;
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Sedimentation rates range from 0.01 to 0.32 cm/yr in 17 sediment box cores from Lake Superior, as determined by (210)Pb geochronology. Shoreline erosion and resuspension of nearshore sediments causes moderate to high (0.05-0.11 cm/yr) sedimentation rates in the western arm of Lake Superior. Sedimentation rates are very high (greater than 0.15 cm/yr) in marginal bays adjoining Lake Superior; and moderate to very high (0.07-0.19 cm/yr) in open lake regions adjacent to marginal bays. Resuspension of nearshore and shoal top sediments in southern and southeastern Lake Superior by storms is responsible for depositional anomalies of (210)Pb profiles corresponding to 1905, 1916-1918, and 1940 storms. Sedimentation rates are very low (0.01-0.03 cm/yr) in the central basins due to isolation from sediment sources. These data indicate that sedimentation rates and processes vary significantly in different regions of Lake Superior.