DURATION AND STRUCTURE OF THE PAST 4 INTERGLACIATIONS

Reanalysis and additional dating of the Devils Hole delta(18)O paleote mperature record confirm that the last interglaciation in the Great Ba sin (the continental analog of marine isotopic substage 5e) lasted sim ilar to 22,000 yr, consistent with the Vostok paleotemperature record which suggests a duration of similar to 19,000 yr for this event in An tarctica. The three preceding interglaciations in the Devils Hole reco rd (analogs of marine isotopic substages 7e, 9c, and 11c) range from 2 0,000 to 26,000 yr in duration. A similar to 20,000-yr duration for th e last interglaciation is consistent with TIMS uranium-series dated se a-level high stands. Thus, the widely held view that interglaciations were of 11,000- to 13,000-yr duration and constituted only about 10% o f mid-to-late Pleistocene climatic cycles needs reexamination. The war mest portion of each interglaciation in the Devils Hole time series is marked by a delta(18)O plateau, signifying apparent climatic stabilit y for periods of 10,000- to 15,000-yr duration. (C) 1997 University of Washington.