The records of glaciation and climate change preserved in sediments on the Canadian and northwest Greenland margins of Baffin Bay pertaining to the last interglacial-glacial transition are remarkably similar. In both regions, warmer than present terrestrial and nearshore marine facies of the last interglacial sensu stricto (s.s.) are overlain by glacial sediments that represent the most extensive advance of continental ice during the last glaciation. Chronometric controls ( 14 C, thermoluminescence, amino acids) indicate an isotope stage 5 age for this advance. Evidence for extensive high-latitude glacial erosion during stage 5 is recorded by abundant pre-Quaternary palynomorphs in Baffin Bay sediment cores, in contrast to a much reduced flux during the remainder of the last glaciation. Warm nearshore marine conditions (seasonally ice free) also occurred near the end of stage 5 along both the eastern Baffin Island and northwest Greenland coasts after the maximum glacial advance; surface water in central Baffin Bay apparently was dominated by meltwater at this time. Subsequently (isotope stages 4, 3, and 2), terrestrial conditions were colder and drier, sea-surface temperatures were lower, and ice margins were retracted. Minimum summer insolation at high latitudes, coupled with mild winters and vigorous meridional oceanic (and presumably atmospheric) circulation characterized the inception phase of the last glaciation during isotope stage 5. In contrast, the 20 ka B.P. (isotope stage 2) “last glacial maximum” was characterized by a zonal circulation regime that resulted in cold and dry conditions over Baffin Bay; the margins of the northwest Greenland and northeast Laurentide ice sheets did not extend beyond the fiords at this time.

Abstract Amino-acid and oxygen isotope data for fossils from terraces of the Palos Verdes Hills and San Pedro areas in Los Angeles County, California, shed new light on the ages of terraces, sea-level history, marine paleotemperatures, and late Quaternary tectonics in this region. Low terraces on the Palos Verdes peninsula correlate with the ∼80-ka and ∼125-ka sea-level highstands that are also recorded as terraces on other coasts. In San Pedro, the Palos Verdes sand (the deposit on what is mapped as the first terrace by Woodring and others, 1946) was previously thought to be a single deposit; amino-acid, oxygen isotope, U-series, and fauna] data indicate that deposits of two ages, representing the 80-ka and 125-ka highstands occur within this unit. Oxygen isotope data show that on open, exposed parts of the Palos Verdes peninsula, ocean waters during the 125-ka highstand were cooler than present (by about 2.3-2.6°C) similar to what has been reported for other exposed coastal areas in California. In contrast, in the protected embayment environment around San Pedro, water temperatures during the 125-ka highstand were as warm or warmer than present. During the 80-ka highstand, water temperatures were significantly cooler than present even in the relatively protected embayment environment of the San Pedro area. Late Quaternary tectonic-uplift rates can be calculated from terrace ages and elevations. Correlation of the lowest terraces around the Point Fermin area shows that the Cabrillo fault has a late Quaternary vertical-movement rate of 0.20 m/ka, based on the difference in uplift rates on the upthrown and downthrown sides of the fault. Elsewhere in the Palos Verdes Hills-San Pedro area, late Quaternary uplift rates vary from 0.32 m/ka to possibly as high as 0.72 m/ka. These rates, which reflect vertical movement on the Palos Verdes fault, are in broad agreement with estimated Holocene vertical rates of movement determined for offshore portions of the fault.