JFWM

Site Name: 
Jorgenson’s Farm
State: 
WI
Location: 
Lake Poygan, near Oshkosh
County: 
Washara
Periods: 
Older Dryas
Taxa: 
Spruce
Deposits: 
Wetland
Glacial
Date Ranges (Cal yr 2σ): 
End: 
14 300 BP
Start: 
14 500 BP
Site Notes: 
  • Early Two Creekan forest

Several samples of spruce from the Jorgensen Farm in Waushara Co., WI were collected with help of Dr. William Mode at UW-Oshkosh. Crossdated tree-ring series of this site contributed to a 510-year composite tree-ring record of Green Bay area overlapping tree rings from five locations dated to the Older Dryas (see plot below).

Tentative overlap of spruce tree rings from the best-fit five sites near Green Bay, NE Wisconsin dated between ca. 14,500 and 14,000 cal yrs BP (Older Dryas). The Jorgensen Farm site chronology is shown with blue line. Color represents different site tree-ring chronologies that can be found in other sections of this website. Upper plot shows site chronology sample depths and lower plot is tree-ring index curves.