AGE AND PALEOECOLOGY OF PLANT FOSSILS ASSOCIATED WITH THE QUAKER SPRINGS STAGE OF LAKE ALBANY, AND A CHRONOLOGY OF DEGLACIAL EVENTS IN THE HUDSON-CHAMPLAIN LOWLANDS, NEW YORK

Allochthonous spruce needles from a thin peat layer in glacial lacustrine sediment under a subaqueous fan of Lake Quaker Springs [Northumberland site] were 11,800 + 115 14C yr B.P. (ETH-5051; AMS), while the age of a sample of bulk sediment was 11,100 + 450 14C yr B.P. (GX14348). The peat occurred at the contact between deep-water Glacial Lake Albany sediment and younger shallow-water sediment of Lake Quaker Springs. The pollen and macrofossil assemblages from the peat and the silty sand immediately above recorded two near-shore environments: rich fen (calcareous wetland) and open spruce woodland. These ages, 84 other published and unpublished radiocarbon dates, and morpho-stratigraphic data from the Hudson-Champlain Valley were combined to interpret the age of deglacial events in the region. Glacial Lake Albany existed from 14,000 to 11,900 14C yr B.P. Lake Iroquois drained into the Hudson and/or Champlain lowlands from 12,600 to 11,100 14C yr B.P. The Quaker Springs stage began at 11,900 14C yr B.P. and the Coveville stage at 11,500 14C yr B.P. The Coveville-Fort Ann stages ended 11,100 14C yr B.P., when the Champlain Sea entered the Champlain Lowlands.