YOUNGER DRYAS BURIED PEAT HORIZON IN THE MONTEZUMA WETLANDS COMPLEX, CENTRAL NEW YORK: IMPLICATIONS FOR LANDSCAPE EVOLUTION AND DEGLACIAL CHRONOLOGY

The Montezuma Wetlands Complex (MWC), located in central New York, encompasses approximately 50,000 acres of private, state, and federally owned lands between Auburn and Seneca Falls, NY. The MWC occupies a northern extension of the Cayuga Finger Lake basin, between the Allegheny Plateau and Erie-Ontario Lowlands physiographic provinces.

Previously unsubstantiated reports of a buried tree horizon at depth led to the location of the study area, south of Routes 5 and 20 in the Montezuma National Wildlife Refuge. Reconnaissance mapping using ground penetrating radar (GPR) was attempted with moderate success in less than ideal conditions. Three exploratory excavations, to a maximum depth of 6 meters showed a complex and diverse stratigraphy, including two peat units containing large amounts of woody material, plant macrofossils, and invertebrate faunal remains. Material suitable for radiocarbon dating was obtained from multiple horizons throughout the stratigraphic column, making it possible to construct a timeline for the site.

A 1-2 m thick upper peat unit yielded tree specimens, along with root and leave specimens; wood from the upper part of the unit was dated to 1820- 1870 cal yr BP; wood from the base of the unit yielded a date of 4400- 4500 cal yr BP. The other peat sequence, yet of unknown thickness, was perhaps the most intriguing unit encountered, found at a depth of 6m, and subsequently dated to 12,100 -12,400 cal yr BP. Three AMS radiocarbon dates on this horizon corroborate that material in this unit dates from the beginning of the Younger Dryas.

The location, age, and observed material at this site are important for understanding the deglacial chronology in central New York State, the evolution of the Ontario Basin, and the impact of sudden climate change during the Younger Dryas.