LATEST PLEISTOCENE AND HOLOCENE SEDIMENT RECORDS FROM WETLANDS IN WESTERN NEW YORK
The stratigraphies represent basal glacial sediments followed by lacustrine units (gyttja in kettle, marl in wetland), succeeded by peat. The timeline of post-glacial changes in sedimentation is constrained by radiocarbon dating, which is used to construct age-depth models for each core. An age model based on four radiocarbon ages in the BM core indicates that the transitions from glacial sediments to lacustrine sediments to bog sediments occurred at ~20.9 ka and ~11.1 ka, respectively. An age model based on six radiocarbon ages from 13DFK-A indicates that the transitions from glacial sediments to lacustrine sediments to bog sediments occurred at ~15.5 ka and ~10.8 ka, respectively.
We have a new constraint on deglaciation of this part of New York. We trust DFK’s basal age of 15.5 ka more than the 20.9 ka age from the BM site because the latter was aquatic material in the marl unit that may be influenced by a hard water effect. Both sites have a transition from lacustrine to peat that occurred around the same time (~ 11 ka); therefore, this transition may have a climatic origin, such as increased aridity. Depositional environments may be further constrained with future analyses.