Luzerne Readvance near Glens Falls, New York
The Woodfordian glacier advanced southward to the terminal moraine on Long Island and then retreated northward up the Hudson Valley. By 15,000 yrs B.P. the ice margin had retreated to the Wallkill Moraine and, after a readvance near Rosendale, New York, retreated a minimum of 130 mi farther north into the Champlain Valley, fronting an expanding Lake Albany. The ice margin then readvanced at least 20 mi into Lake Albany, to the Luzerne Mountain gorge of the Hudson River west of Glens Falls, New York. The type section for the Luzerne readvance is designated as that at the Luzerne Mountain gorge where the Luzerne readvance till occurs, over sands of Glacial Lake Warrensburg, over main Woodfordian till, and over contorted, pre-Woodfordian lacustrine clays. The western margin of the readvance is reconstructed from isolated morainal segments and associated outwash, and from the postulated ice dam for Lake Warrensburg. Pine Log Camp bog, developed in Luzerne readvance outwash, yielded an 8.0 m record. The base of the bog was dated at 13,150 ± 200 yrs B.P. in the herb pollen zone, and the base of the spruce pollen zone was dated at 12,400 ± 200 yrs B.P. The herb pollen zone was identified from several herbs, several grains of the genus Shepherdia, and a 35 percent maximum of nonarboreal pollen. The spruce, pine, and oak pollen zones are all well represented. Rapid encroachment of vegetation, illustrated by the time transgressive spruce zone and kettle morphology, are cited as evidence that bog deposition closely postdates glacial recession. The Luzerne readvance is pre-Port Huron in age and is correlated with the Gowanda Moraine of western New York, the Valley Heads Moraine of central New York and the Mohawk Valley, and the Burlington drift of Vermont. The Bridport readvance in the mid-Champlain Valley is inferred to Be Port Huron in age and is correlated with the Hamburg Moraine in western New York, the Waterloo-Auburn Moraine in central New York, and the Valley Heads Moraine in the Mohawk Valley. The relationship of local glaciers in the Adirondack Mountains and Lake Warrensburg, indicates that local glaciers were active during the Luzerne readvance and also are pre-Port Huron.