Younger glacial drift

Till. Hard, blue-gray to gray concrete-like mixture of clay, silt, sand, and gravel deposited as end or recessional moraine. Principally Wisconsin in age.
State Washington
Name Younger glacial drift
Geologic age Pleistocene
Lithologic constituents
Unconsolidated > Coarse-detrital (Glacial-till)gravel and sand
Unconsolidated > Fine-detrital (Glacial-till)silt and clay
Comments Possibly some outwash from the Fraser Glaciation (which encompassed the Vashon and Sumas Stades) occurs in this unit; most of it, however, is mapped within WAQg1o.
Stratigraphic units Vashon drift (moraine and till members); Sumas Drift (in part)

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.

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.

NGMDB product
Counties King - Kitsap - Lewis - Mason - Pierce - Skagit - Snohomish - Stevens - Thurston - Whatcom