• Climate tree-ring proxies near Preboreal/Late Younger Dryas transition, from Upper Peninsula, Michigan
This sample from Calumet County, Wisconsin, had been donated to the University of Wisconsin-Green Bay by Jordan Korotev, a Wisconsin District Forester. The wood had been identified as spruce by R. C. Koeppen of the USDA Forest Products Lab on March 3, 1969. The wood was kept in a small display case and loaned to our project in early summer 2004 by Prof. Ron Stieglitz and returned to UW-Green Bay in July 2005. The specimen has more than 270 rings and was radiocarbon dated at 11,543 ± 72 yrs BP.