Deglaciation in the southeastern Laurentide Sector and the Hudson Valley – 15,000 Years of vegetational and climate history

In this field trip, we provide a review of the significant controversy concerning the timing of deglaciation in the Hudson and Wallkill Valleys. We outline the differences in methodology and chronology with a circular route throughout the Hudson and Wallkill valleys. We begin the trip at Lake Mohonk near New Paltz led by Kirsten Menking and Dorothy Peteet, then continue to the “black dirt” region of the Wallkill Valley where John Rayburn has contributed a new GIS model of deglaciation in the Wallkill Valley and Guy Robinson will review the history of fossil mammals, including mammoths. From this point we travel southeast to a rare exposure of glaciolacustrine beds on the west side of the Huson River, described by Byron Stone and John Rayburn, and on to Croton Marsh at Croton Point, New York where Dorothy Peteet will review the marsh histories of the region.

A recent review of literature relating to the last glacial recession in the Hudson Valley indicates that the timing of de - glaciation is very controversial (Peteet et al., 2006; Peteet, in review; Balco et al., 2006; Balco et al., 2009; Schaefer, 2007). Some questions to consider:

1) How does timing of new lake basal dates at the margin of the ice (Staten Island) compare with sites to the north and inland (ie. Mohonk)?

2) What is the vegetational history of the region and how does it compare with Deevey’s classical southern New England stratigraphy?

3) What is the latest model of the deglaciation of the Wallkill Valley?

4) What have the Hudson marshes added to our understanding of the vegetation and landscape history, particularly in the last few millennia?