November 04, 2004
The above photo showing Green Lake was taken this past September from Clark’s Reservation State Park, located in Jamesville, New York. Green Lake is a remnant of a prehistoric waterfall that plummeted over a nearly 175 ft (53 m) precipice to the beautifully carved round, blue plunge pool. The caprock of this ancient falls is an Onondaga limestone (from the Devonian Period). The approximately 60 ft (18.2 m) deep lake found within the scoured plunge pool is called a meromictic lake, one in which the bottom waters never undergo the seasonal "turn over" typical of most mid-latitude lakes -- no mixing with the upper layers of the lake. Bottom waters of meromictic lakes are often depleted in oxygen and saturated with gases like carbon dioxide (CO2).
Approximately 10,000-12,000 years ago, the continental ice sheet covering the northeast U. S. began to melt and retreat, sending torrents of meltwater through gorges and valleys of central New York. The ancient cataract at Clark’s Reservation Park had a water flow equal to the volume of the American Falls at Niagara. This impressive flow lasted on the order of about 2,000 years. Clark’s Reservation Park offers magnificent hikes around the waterfall’s rim as well as trails of various difficulty into the woodlands, where one might encounter the fern Hart’s Tongue, which is reportedly found only at Clark’s Reservation.