STRATIGRAPHY AND PALEOECOLOGY OF A POSSIBLE INTERGLACIAL SITE, NORTHERNMOST ELLESMERE-ISLAND, CANADA

An extensive stratigraphic section at Cape Alfred Ernest on the Wootto n Peninsula, northwest Ellesmere Island contains six lithofacies which appear to record two glacial phases separated by an organic layer. (1 ) A lower massive gravel records a pre-ice advance outwash phase; (2) massive fine-grained sediments record a period of non-glacial marine d eposition when sea-level was higher than present; (3) a massive diamic ton records the advance of ice across the site; (4) intermediate strat ified beds record supraglacial and proglacial outwash, and include an organic layer; (5) massive diamicton grading down-valley to stratified diamicton and then massive, sheared diamicton, overlain by laminated fine-grained sediments with dropstones, recording the last (late Wisco nsinan) glaciation; (6) upward-coarsening sands and gravels record pro glacial outwash and grade to raised marine deltas. Radiocarbon dates o f 39270 +/- 640 and > 51 000 yr BP were obtained on samples from the o rganic layer by accelerator mass spectrometry and conventional radioca rbon dating, respectively. Palaeoecological data suggest that the orga nics accumulated in a wet sedge meadow environment when the climate wa s warmer than present. Stratigraphic considerations suggest that the o rganic layer represents an interglacial interval which, if valid, indi cates that the site constitutes the northernmost interglacial stratigr aphy in the Canadian Arctic. Alternatively, the organic layer may date to Plio-Pleistocene times.