Cirques of the Presidential Range, New Hampshire, and surrounding alpine areas in the northeastern United States

Evidence for rejuvenation of cirque glaciers following wastage of continent al ice remains elusive for the Presidential Range and Mount Moosilauke of N ew Hampshire, Mount Katahdin and the Longfellow Mountains of Maine, and the Adirondack Mountains of New York. At Ritterbush Pond in the northern Green Mountains of Vermont, radiocarbon ages from lake sediment cores suggest th at a low-altitude valley head, located up-valley of a series of cross-valle y moraines, was ice-free by 11,940 C-14 yrs BP (Bierman et al., 1997). Alth ough some workers argue that these moraines in Vermont are evidence for cir que glaciation, the moraines could have been formed by a tongue of continen tal ice during deglaciation. At Johnson Hollow Brook valley in the Catskill Mountains of New York, a radiocarbon age from basal sediments in a pond da mmed by a moraine suggests that glacier ice may have persisted until 10,860 C-14 yrs BP (Lederer and Rodbell, 1998). Because this moraine appears to h ave been deposited by a cirque glacier, the radiocarbon age provides the be st evidence in the northeastern United States for cirque glaciation post-da ting recession of continental ice. Cirque morphometric data, compiled from newly available topographic maps, add to the conundrum that these two sites in the Green and Catskill Mountains should not be nearly as favorable for maintaining local glaciers postdating icesheet recession as higher-altitude and better-developed cirques in the Presidential Range and Mount Katahdin, where evidence for post-icesheet cirque glaciers is lacking.