LAKE ALBANY, THE SOUTHERN END

The southern end of Glacial Lake Albany is defined by the Newburgh and Beacon-Fishkill deltas, north of the Hudson Highlands; the Cold Spring delta within the Highlands; the Haverstraw and Archville deltas south of the Highlands; and the Maurer delta at Perth Amboy NJ. Lake Albany was dammed by the Harbor Hill Moraine at The Narrows between Staten Island and Perth Amboy. There was no ocean south of the moraine; rather an outwash plain descending gently to the south. The lake was perched more than 300 ft above then existing sea level. There were five possible thresholds for Lake Albany; 1) southward over the moraine; 2) eastward through Hell Gate via Spuyten Duyvil or 3) the East River; or 4) westward via Sparkill Gap or 5) Kill van Kull.

Evidence from detailed quadrangle mapping refutes previous models that suggested Lake Hudson (Lake Albany) was co-extensive with Lakes Hackensack, to the west, and Flushing, to the east. Lake Hackensack may have been ±30 ft lower than Lake Albany; ±10 ft higher than subsequent Lake Coveville. If so, connections 4) (+25 ft now) and 5) (-30 ft now) must have remained closed from 25,710 to 14,000 yBP (Calendar years BP). While Lake Albany didn’t drain into Lake Hackensack, the latter may well have existed long enough to drain into Lake Coveville. Lake Flushing was at least ±30 ft and probably ±110 ft lower than Lake Albany and ±70 ft lower than Lake Coveville. So the threshold for Lake Albany must have been at 1), 2), or 3). At present, we favor 2) Spuyten Duyvil (-16 ft now) because it is a relatively narrow bedrock defile that could have withstood the powerful erosion of the two freshwater slugs WD-17 (=R8), 19,500 to 17,800 yBP, and WD-15 (=R7), 15,500 to 14,800 yBP that channeled Great Lakes drainage down the Hudson Valley before and after the Rosendale Readvance. When the level dropped ±40 ft, 700 years later, causing Lake Coveville and then Lake Fort Ann, another 900 years later, the threshold may have disintegrated slightly or shifted south to the 3) East River (-39 ft now) or 1) The Narrows.

Deltas for Lake Fort Ann project southward at ±40 ft below Lake Coveville. Regardless of its nature in the north, at the southern end it must have been a deep viable lake. The breaching of the Harbor Hill Moraine at the Narrows (-102 ft now) had to have been responsible for lowering Lake Fort Ann, 13,200 to 13,100 yBP, because the barrier for Lake Flushing, in Long Island Sound, would have blocked eastward drainage.