By Bryan Thompson
There are two major areas of peat deposit in the township: Beaver Creek Swamp and the Spooner Flats. There are various other smaller deposits throughout the town in isolated valleys, potholes and streambeds.
Beaver Creek is arguably one of the largest geological features in the entire township of De Kalb. Beaver Creek arises in the town of Macomb and enters the Oswegatchie River in the Town of Oswegatchie about a mile after it leaves the town of De Kalb. In the Town of De Kalb, the Beaver Creek swamp is one quarter to one and a half miles wide and extends along the entire 10 mile Northern boundary of the Township. It also includes a second branch along West Beaver Creek or Osborn Creek extending to the Gouverneur town line at two points.
Spooner’s Flats lie northwest of Richville and the Oswegatchie River. It is bounded by the Walker Road, the Reese Road and by the Colton Road, although the deposits continue along the Oswegatchie River beyond the Snowshoe.
All peat deposits in the township share a common history and so will be covered as one in this article.
Outline of Major De Kalb Peat Deposits
About ten to twelve thousand years ago, at the end of the last ice age the entire township was covered in an ice sheet over a mile thick at its peak. This vast river of ice ground away at the earth, removing all the soil as it went. Both the Beaver Creek Valley and the Oswegatchie Valley are ancient fault lines. These cracks in the earth, similar to the Finger Lakes, may be several hundred feet deep.
As the glacier retreated it melted slowest in the areas where it was the thickest. The giant potholes, known locally as” Indian Wells” along the south rim of Beaver Creek swamp near Streeter Rd. are clear evidence of this. These holes, up to 8 foot in diameter and 14 feet deep, are located on an almost shear cliff about 75 feet above the current floor of Beaver Creek. They were formed when a massive glacial remnant (imagine an ice cube the size of Beaver Creek) filled the valley, towering over the surrounding exposed countryside. Huge melt-water waterfalls cascaded off of the side of the glacier. Rocks swirling around at the base of the waterfalls ground out the potholes over hundreds of years. These same glacial streams deposited the gravel banks found today in the Maple Ridge area.
The glaciers were so heavy that they actually compressed the earth under them. As the glaciers retreated, the earth slowly re-expanded like a released sponge. Since the glacier left the fault valleys last, these areas were the last to decompress. Water from the surrounding areas collected here forming two large lakes. These lakes were several hundred feet deep. As plant life returned and silt flowed into the lakes, they gradually filled up with silt and lacustrine clay (limnic peat).
Eventually the lakes became shallow enough to support reeds and sedges. These reeds and sedges flourished and died, falling to the bottom of the lake. Decomposing without oxygen, over thousands of years, they began to build up a layer of high carbon raised mire peat. Eventually, the bogs rose to the point where there was little or no water left and they began to support trees and other types of non-aquatic plant life. Today Osborn Lake is all that remains of the prehistoric Beaver Creek Lake.
In 1968, Cornelia Cameron, a peat specialist with the US Geological Survey, did test drillings in the Beaver Creek Swamp 1/2mile Northeast of Osborn Lake. In this region, she found a layer of high quality woody reed sedge peat varying in thickness from ten to forty feet lying on a bed of sticky-blue gray clay. These deposits are projected to extend through out the area. Similar deposits are conjectured to exist in Spooner Flats.
Brown, C. ErvinNew Talc Deposit in St Lawrence County New YorkUS Government Printing Office, Washington, DC 1969.
Brown, C. ErvinMineralization, mining and mineral resources in the Beaver creek area of the Grenville Lowlands In St Lawrence County, New
YorkUS Government Printing Office, Washington, DC 1983.
Johnson, Samuel W.Peat and Its UsesOrange Judd & Company, New York 1866.