Ice Age Remnants

The Housatonic River originates from branches to the west and east of Pittsfield. Its flood plains expand as it comes south to Falls Village, Connecticut, where it abruptly drops onto the beginnings of another plain or two on its way to sea level at Stratford, Connecticut, where its fresh water mixes with the salt of Long Island Sound. In addition to generating electricity on its several drops to the Sound, it passes under many bridges, and some picturesque covered bridges, such as this one in Sheffield.
The Wisconsin Glacier some 10,000 years ago excavated the eventual course of the Housatonic today, depositing its terminal debris as Long Island, Cape Cod, and the near islands. As the glacier melted back, torrents of water eroded through several rock sills that held back great lakes, including big ones here and a bit higher in Stockbridge, and then drained them. As lakes, they collected much blue and yellow clay, various silts and gravels, sundry forest debris, and even recently discovered ancient mammoth carcases (locations undisclosed). These sediments filled the several lake basins, creating the present fertile flood plains.
Today the river meanders through the almost flat plains, slowly eating away at the outer bends along its many meanders and redepositing some of that material downstream on the inside of the lower bends. Except in flood, the river may be 10 feet below the level of the plain at the outside of a bend, and perhaps just five or six feet below the inner part, constantly carrying away sediments and lowering the flood plain. As the river cuts into the older banks, it encounters many ancient trees washed into the ancient lake by the pulsing floods from retreating ice. Those increasingly distant floods next carried soils that soon buried the downed trees. The cycles may have repeated many times over thousands of years, leaving us today with the expectation in a few thousand years of yet another ice age and much change to our community and remnant Sheffield Plain.
The ancient trees, buried some 10 feet below the level of the plain and preserved under the water table, are exposed by the erosion of the river, revealing a time, perhaps, when far upstream an immense ice dam broke and floods of biblical proportions swept all of the emerging valley forests into a heap, just to be buried by later sediments, and now revealed for our parochial pleasure and speculations about the past and future of our Sheffield Plain.