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Clear Lake core CL-73-4 records fluctuating abundances of oak pollen during the last glacial/interglacial cycle that correlate remarkably well with fluctuations in extensive pollen records from Grande Pile in France and Tenaghi Phillipon in Macedonia, as well as with the oxygen-isotope records from deep-sea cores. The record correlates less closely with other extensive records, including those for Lake Biwa, Japan, and Sabana de Bogotá, Colombia. Correlation of the record with the early Weichselian climatic sequence of northwestern Europe is excellent; both sequences show a series of five cryomer/thermomer fluctuations between the end of the last interglaciation (Eemian/Konocti, which is correlated here with the end of marine oxygen-isotope Stage 5e) and the onset of full continental glaciation at the end of Stage 5a. The fluctuations correlate both in their relative durations and in their relative amplitudes.

The Clear Lake record also correlates with various North American sequences. The Sangamon interval of the mid-continent area correlates with the entire Konocti thermomer and early Pomo cryomer interval, and correlations with the glacial sequences of the Sierra Nevada and Rocky Mountains suggest that some Tahoe, Mono Basin, and Bull Lake moraines may be of Sangamon age.

The proposed correlations of the Clear Lake record with other sequences have not been proved. The overall impression, however, is one of remarkable consistency, and it is likely that further work will provide more evidence in support of the sequence of five cryomer/thermomer cycles between the end of the last interglacial period and the onset of full glacial conditions about 70,000 years ago. This sequence is much more complicated than has been generally recognized, although parts of it have been known for many years. The sequence, which has now been found in several widely separated areas, should no longer be ignored.

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