Glaciolacustrine deposits

Fine-grained sand and silt, well-stratified, with some gravel, clay, and diatomaceous earth. Contains clastic dikes in Walla Walla area.
State Washington
Name Glaciolacustrine deposits
Geologic age Pleistocene
Lithologic constituents
Major
Unconsolidated > Fine-detrital > Silt (Glacial-esker)
Unconsolidated > Coarse-detrital > Sand (Glacial-esker, Alluvial)
Minor
Unconsolidated > Coarse-detrital > Gravel (Glacial-esker)
Unconsolidated > Fine-detrital > Clay (Glacial-esker)
Incidental
Igneous > Volcanic (Pyroclastic)
Comments Recent maps show part of this unit near Walla Walla covered with Quaternary loess (periglacial) and minor Holocene dune sand and alluvium (nonglacial) as well as outburst flood deposits from glacial Lake Missoula. Some flood deposits also have ash layers or tephra deposits.
Stratigraphic units Nespelem silt (in 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.

Schuster, J.E., 1994, Geologic Map of the Walla Walla 1:100,000 quadrangle, Washington: Washingtone State Division of Geology and Earth Resources Open-File Report 94-3, 18 p.

Schuster, J.E., Gulick, C.W., Reidel, S.P., Fecht, K.R., Zurenko, S., 1997, Geologic Map of Washington--Southeast Quadrant: Washington Division of Geology and Earth Resources Geologic Map GM-45, scale 1:250,000.

Stoffel, K.L., Joseph, N.L., Waggoner, S.Z., Gulick, C.W., Korosec, M.A., Bunning, B.B., 1991, Geologic Map of Washington--Northeast Quadrant: Washington Division of Geology and Earth Resources Geologic Map, GM-39, scale 1:250,000.

NGMDB product
Counties Adams - Benton - Douglas - Ferry - Franklin - Grant - Lincoln - Okanogan - Pend Oreille - Spokane - Stevens - Walla Walla - Yakima