Younger glacial drift

Younger glacial drift, undivided. Till, outwash, and associated deposits; sorted and unsorted sand, gravel, silt, and clay. Includes some alluvium.
State Washington
Name Younger glacial drift
Geologic age Pleistocene
Lithologic constituents
Major
Unconsolidated > Fine-detrital (Glacial-till, Glacial-outwash, Alluvial)
Unconsolidated > Coarse-detrital (Glacial-till, Glacial-outwash, Alluvial)
Comments Includes nonglacial sediments and peat beds locally. Example: Whidbey Formation in Central Puget Lowland; peat beds in Vashon Stade. Principally Wisconsin in age. Difficult to distinguish from Qg2 by lithology; distinction is in age difference only. Some stratigraphic units may occur in both units, regardless of age.
Stratigraphic units Vashon drift; Possession Drift (in part); Whidbey Formation (in small part)
References

Huntting, M.T., Bennett, W.A.G., Livingston, V.E.Jr., and Moen, W.S., 1961, Geologic Map of Washington: Washington Division of Mines and Geology, scale 1:500,000.

Easterbrook, D.J., 1976a, Quaternary Geology of the Pacific Northwest, in Mahaney, W.C., ed., Quaternary Stratigraphy of North America: Stroudsberg, PA, Dowden, Hutchinson and Ross, p. 441-462.

Easterbrook, D.J., Crandell, D.R., Leopold, E.B., 1967, Pre-Olympia stratigraphy and chronology in the central Puget Lowland, Washington: Geological Society of America Bulletin, v. 78, no. 1, pp. 13-20.

Jones, M.A., 1999, Geologic Framework for the Puget Sound Aquifer System, Washington and British Columbia: U. S. Geological Survey Professional Paper 1424-C, 31 p., 18 pls.

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