Lackawanna and Wyoming Counties, Factoryville Quadrangle
The South Branch of Tunkhannock Creek,
locally known as Nokomis Creek, is a riffle
and pool stream with scattered boulders. The pictured suspension
bridge is nearly on the county line. On the southern (north-facing)
hillside, about 50 feet of till covers the bedrock.
Glacial ice flow in this area was from N30°E to S30°W as
evidenced by bedrock striations on a hilltop in nearby Factoryville.
Bedrock ledges and the bedrock areas of the stream bottom are Late Devonian in
age (~375 million years) and a part of the Catskill formation of sandstone and
shale. The stream is "hungup" on this bedrock, unable to cut down to its
original depth as it was prior to the time the glacier filled the valley with
till.
The till on the hillsides is compacted "lodgement
till", materials left behind by the melting bottom of the glacier.
The massive weight of the ice compressed the till into dense
formations.Stone walls along the trails in the woods indicate that
bedrock is buried under many feet of till. The walls have many
rocks with rounded edges, the sign of erosion, indicating they had
been roughed up by the glacier. If bedrock were near the
surface, the pieces, or clasts, would be more angular and tabular,
indicating that they had been broken off with sharper edges and had
been exposed to less mechanical weathering.
In the early 1900s the stream was dammed, backing up
a small lake once used for boating and swimming classes at the
College. A small slough just downstream from the suspension
bridge is wet year round, being fed by groundwater seepage through
the fine-grained sediments of the hillside. Now the slough is
an important breeding area for amphibians.
