Middle Wisconsin glacial advance into the Appalachian Plateau, Sixmile Creek, Tompkins Co., NY
| Autor: | Norton G. Miller, Daniel E. Karig |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
010506 paleontology
geography Varve Plateau geography.geographical_feature_category 010504 meteorology & atmospheric sciences Sediment Structural basin 01 natural sciences Archaeology Tundra law.invention Paleontology Arts and Humanities (miscellaneous) law Stage (stratigraphy) General Earth and Planetary Sciences Radiocarbon dating Glacial period Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Quaternary Research. 80:522-533 |
| ISSN: | 1096-0287 0033-5894 |
| DOI: | 10.1016/j.yqres.2013.08.008 |
| Popis: | Areal mapping of the middle Wisconsin varved clay site along Sixmile Creek near Ithaca, New York, has revealed a much more widespread and varied array of sediments than previously thought. Lacustrine clays, some varved, are interbedded with sands and gravels interpreted as sub-aqueous fan deposits, and both are overlain by a deformation till. Nine radiocarbon dates indicate a 34–37 14C ka BP age for the lacustrine sediment, with the deformation till less than a few thousand years younger. Beneath this sequence is a deposit dated at ± 42 14C ka BP. Both strata represent a tundra climate with a mean July temperature of about 10°C. The Sixmile Creek deformation till must correlate with the 35 14C ka BP till along the Genesee River, 125 km to the NW, and defines a Cherrytree stade glacial advance into the Appalachian Plateau, much further south than what has generally been accepted. Such an advance would require drainage from a proglacial lake in the western Ontario basin to flow westward instead of northeastward. The Sixmile strata suggest a colder than accepted middle Wisconsin stage. Recent data indicate that this stage is one of progressive cooling, with large climatic fluctuations. |
| Databáze: | OpenAIRE |
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