A MULTIFACETED STUDY OF THE MONTEZUMA WETLANDS COMPLEX, CENTRAL NEW YORK STATE: IMPLICATIONS FOR LANDSCAPE EVOLUTION AND POSTGLACIAL CHRONOLOGY

The Montezuma Wetlands Complex (MWC) 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. An interdisciplinary study examining the geomorphology, paleoecology, and chronology of the MWC has evolved, utilizing data collected from ground penetrating radar (GPR), excavation test pits, and boreholes.

A site with three ~6 m deep excavations, 2 km north of Cayuga Lake, revealed multiple horizons with dateable material, notably two peat units. The upper peat, from 1.5−2.4 m, produced numerous tree specimens and associated macrofossils. The top of the unit dates to 1,890 ±20 ¹⁴C yr BP; the base of the unit dates to 3,990 ±20 ¹⁴C yr BP. The lower peat was encountered at a depth of 6 m, and multiple samples date to 10,350−10,400 ¹⁴C yr BP. The paleoecology at the site can be interpreted from plant macrofossils and invertebrate faunal remains. Completely different stratigraphy was encountered at a test pit located 5 km north of the initial excavation site, with only peat encountered to a depth of 1.82 m; basal age of the peat unit is 6,200 ±47 ¹⁴C yr BP.

Multiple boreholes have revealed additional complexity: a borehole to ~53 m on the initial excavation site failed to locate bedrock; two additional holes located near the second excavation site found bedrock at ~12 m and ~22 m. The 53 m deep hole confirmed previous stratigraphy and provided more dateable material; the dates are pending. Core from the northern boreholes reveals a different stratigraphy. Previous interpretations suggest the bedrock trough occupied by the modern MWC deepens to the north. Initial results suggest bedrock topography is more complicated than originally proposed, although additional data need to be collected.

Collection of additional core and borehole data will help with sediment/landform analysis. The location, age, and observed material at this site are important for understanding the deglacial and postglacial chronology in central New York State, ties between glacial Lake Iroquois and Cayuga Lake, and the evolution of the Montezuma Wetlands Complex.