MIDDLE WISCONSINAN SEDIMENTS AND PALEOECOLOGY OF CENTRAL BRITISH-COLUMBIA - SITES AT NECOSLIE AND NAUTLEY RIVERS

At two sites in central British Columbia, sediments with dispersed org anic matter, underneath Fraser Glaciation deposits, are interpreted as nonglacial deposits of Middle Wisconsinan age (Olympia Nonglacial Int erval). At Necoslie River, undated sand with dispersed organic matter, thought to be fluvial in origin, is overlain by Fraser drift. At Naut ley River, similar sand contains plant detritus that has yielded C-14 ages of 38 230 +/- 410 BP (Beta-88557) and 42460 +/- 670 BP (Beta-8855 8). Pollen assemblages of the sediments with dispersed organic matter at the Necoslie River and Nautley River sites are similar: both assemb lages are dominated by herb pollen, with a lesser amount of tree polle n. The pollen assemblages are thought to reflect a tundra-type vegetat ion. Because vegetation in the area is presently dominated by spruce a nd subalpine fir forest, climate during deposition probably was much c ooler than today. Data presented here support the contention of other studies in western Canada that cooler climatic conditions existed for some time during the Middle Wisconsinan.