Radiocarbon Age Constraints on Rates of Advance and Retreat of the Puget Lobe of the Cordilleran Ice Sheet during the Last Glaciation
- 1 November 1998
- journal article
- Published by Cambridge University Press (CUP) in Quaternary Research
- Vol. 50 (3), 205-213
- https://doi.org/10.1006/qres.1998.2004
Abstract
Calibrated radiocarbon dates of organic matter below and above till of the last (Fraser) glaciation provide limiting ages that constrain the chronology and duration of the last advance–retreat cycle of the Puget Lobe in the central and southeastern Puget Lowland. Seven dates for wood near the top of a thick proglacial delta have a weighted mean age of 17,420 ± 90 cal yr B.P., which is the closest limiting age for arrival of the glacier near the latitude of Seattle. A time–distance curve constructed along a flowline extending south from southwestern British Columbia to the central Puget Lowland implies an average glacier advance rate of ca. 135 m/yr. The glacier terminus reached its southernmost limit ca. 16,950 yr ago and likely remained there for ca. 100 yr. In the vicinity of Seattle, where the glacier reached a maximum thickness of 1000 m, ice covered the landscape for ca. 1020 yr. Postglacial dates constraining the timing of ice retreat in the central lowland are as old as 16,420 cal yr B.P. and show that the terminus had retreated to the northern limit of the lowland within three to four centuries after the glacial maximum. The average rate of retreat was about twice the rate of advance and was enhanced by rapid calving recession along flowline sectors where the glacier front crossed deep proglacial lakes.Keywords
This publication has 25 references indexed in Scilit:
- Late-Glacial and Early Holocene Sea-Level Fluctuations in the Central Puget Lowland, Washington, Inferred from Lake SedimentsQuaternary Research, 1994
- Glaciofluvial infilling and scour of the Puget Lowland, Washington, during ice-sheet glaciationGeology, 1994
- Late Holocene Fluctuations of the Fiord Glacier System in Icy Bay, Alaska, U.S.A.Arctic and Alpine Research, 1989
- Forecasting the Effects of a Planned Reservoir which will Partially Flood the Tongue of Unteraargletscher in SwitzerlandAnnals of Glaciology, 1989
- Mass Balance and Sliding Velocity of the Puget Lobe of the Cordilleran Ice Sheet During the Last GlaciationQuaternary Research, 1986
- Pollen and Lignin Records of Late Quaternary Vegetation, Lake WashingtonScience, 1982
- A Record of Late Quaternary Vegetation from Davis Lake, Southern Puget Lowland, WashingtonQuaternary Research, 1981
- Isostatic effects of the last glaciation in the Puget Lowland, WashingtonOpen-File Report, 1981
- Late Pleistocene Stratigraphy and Chronology in Southwestern British Columbia and Northwestern WashingtonGSA Bulletin, 1965
- Glacial Lakes of Puget Sound: Preliminary PaperThe Journal of Geology, 1910