Mid-Wisconsinan Climate Reconstruction Based on Fossil Beetles from Six Mile Creek, Ithaca, New York

Abstract

The history of the Mid-Wisconsinan sub-stage in northeastern North America is one of large climatic oscillations. Fossil beetles were extracted from two horizons at the Six Mile Creek site, New York. A total of 738 individuals was identified, representing 16 species. The beetle fossils, as well as those of plants, indicate a range of habitats from well-drained uplands to moist boggy lowlands, indicative of a tundra environment. A modified Mutual Climatic Range (MCR) method was used for the paleoclimatic reconstruction. SAS and ArcGIS programs were used to construct 95% confidence ellipses from which mean July temperature was inferred to be in the range of 8.7 ºC to 11.4 ºC and mean January temperature in the range of -24.6 ºC to -15.3 ºC. The estimated mean July temperature is 9.0 °C to 11.7 °C cooler than in central New York State at present.