PLEISTOCENE BEETLES AND PLANTS FROM NEAR SLIPPERY ROCK, PENNSYLVANIA, FROM THE TITUSVILLE INTERSTADE (MIS 3)
The biota indicates a wetland environment (bog, fen, or lake shore) in a spruce-dominant forest similar to those found currently in central Canada. Two radiocarbon samples from this horizon have ages of 42,110±1280 BP (41006 cal BC to 45833 cal BC) (PSUAMS-8083) and 42,190±1290 BP (41029 cal BC to 45938 cal BC) (PSUAMS-8082).
Below the silt and peat there is a 12.2 ft-thick sand that bears fine filaments of plant material. Within that sand at 39.2 ft bls, a pollen (n=307) and spore (n=8) assemblage has the composition 57.8% Picea, 32.4% Pinus, 7.0% Cyperaceae, 1.6% Selaginella selaginoides, and 0.9% Huperzia selago, and 0.3% Cichoroideae. Elytra (wing cases) of the ground beetle Blethisa catenaria, a ground beetle which lives exclusively on tundra, was also found at 39.2 ft bls. The sediment at 39.2 ft bls was deposited in a tundra-spruce environment similar to that today on the North Slope of Alaska and the Canadian Arctic.
The faunal and floral changes indicate climatic warming from the lower to the upper organic horizons. The mean July temperature at 39.2 ft bls is estimated to be 11-12°C and at 32.0 ft bls 15-17°C compared to 21°C at Slippery Rock today.