Discussion

Despite many irregularities in dating, proxy interpretation, and site analysis, a number of records along the PEP 1 transect contain full glacial to early Holocene paleolimnological information that identifies the past distribution and strength of large-scale climate processes affecting lake levels and limnological processes (Fig. 22). The northernmost record, Lake Zagoskin, reflects a warming of global climate related to shrinkage of continental ice sheets in the Northern Hemisphere. The persistence of ice in Canada throughout much of the late glacial period has compromised the search for full and late glacial records at those latitudes. Presumably, such records would also document progressive limnologic change related mostly to ice disappearance and replacement of anticyclonic circulation around the ice sheet by jet stream- (westerly) dominated climate systems present today.

The Klamath Lake record from Caledonia Marsh appears to document the retreat of cold, dry, easterly circulation around the ice sheet-induced, high-pressure system and its replacement by westerly storm tracks. It is difficult to tell from this lake margin site to what extent late glacial limnological fluctuations reflect pro-

FIGURE 21 Lake stage elevation curves for Lago sa. (Data from Stine and Stine, 1990.)

FIGURE 21 Lake stage elevation curves for Lago sa. (Data from Stine and Stine, 1990.)

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