Gravel, sand, and silt; glacial outburst flood deposits, outwash, fanglomerate, and alluvium, undivided; Pleistocene (IDQpg;0)

State	Idaho
Name	Gravel, sand, and silt; glacial outburst flood deposits, outwash, fanglomerate, and alluvium, undivided; Pleistocene
Geologic age	Pleistocene
Original map label	Qpg; Qp?g
Comments	Includes younger alluvial and older glacial-outwash and alluvial deposits, deposited during an interval of high runoff, probably caused by seasonal melting of glaciers. Includes glacial-lake outburst flood deposits, large deposits of stream and terrace gravel, and extensive alluvial fans in fault-bounded valleys of southern Idaho.
Primary rock type	stratified glacial sediment
Secondary rock type	alluvium
Other rock types	outwash; alluvial fan; alluvial terrace
Lithologic constituents	Major Unconsolidated > Coarse-detrital > Gravel (Alluvial)alluvial fan and mainstream gravel Unconsolidated > Coarse-detrital > Gravel (Glacial, outwash)outwash and flood gravel, undivided Minor Unconsolidated > Coarse-detrital > Sand (Alluvial)interstitial and distal alluvial sand Unconsolidated > Coarse-detrital > Sand (Glacial, outwash)interstitial and distal outwash sand Incidental Unconsolidated > Fine-detrital > Silt (Alluvial)distal and slackwater alluvial silt Unconsolidated > Fine-detrital > Silt (Glacial, outwash)distal and slackwater outwash silt
Map references	Bond, J.G., Kauffman, J.D., Miller, D.A., and Venkatakrishnan, Ramesh, 1978, Geologic map of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, with contributions from U.S. Geological Survey, scale 1:500,000.
Unit references	Bond, J.G., Kauffman, J.D., Miller, D.A., and Venkatakrishnan, Ramesh, 1978, Geologic map of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, with contributions from U.S. Geological Survey, scale 1:500,000. Scott, W.E., 1982, Surficial geologic map of the eastern Snake River Plain and adjacent areas, 111o to 115o W., Idaho and Wyoming: U.S. Geological Survey Map I-1372, scale 1:250,000. [http://pubs.er.usgs.gov/publication/i1372] Rember, W.C., and Bennett, E.H., 1979, Geologic map of the Pocatello quadrangle, Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, Geologic Map Series, Pocatello 2o quadrangle, scale 1:250,000. Rember, W.C., and Bennett, E.H., 1979, Geologic map of the Twin Falls quadrangle, Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, Geologic Map Series, Twin Falls 2o quadrangle, scale 1:250,000. Griggs, A.B., 1973, Geologic map of the Spokane quadrangle, Washington, Idaho, and Montana: U.S. Geological Survey Map I-768, scale 1:250,000. [http://pubs.er.usgs.gov/publication/i768] Joseph, N.L., 1990, Geologic map of the Spokane 1:100,000 quadrangle, Washington - Idaho: Washington Division of Geology and Earth Resources, Open File Report 90-17, scale 1:100,000, pamphlet 29 p. Rember, W.C. and Bennett, E.H., 1979, Geologic map of the Pullman quadrangle, Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, Geologic Map Series, Pullman 2o Quadrangle, scale 1:250,000.
Geographic coverage	Ada - Adams - Bannock - Benewah - Bingham - Blaine - Boise - Bonner - Bonneville - Boundary - Camas - Canyon - Cassia - Clark - Custer - Elmore - Fremont - Gem - Gooding - Idaho - Jefferson - Jerome - Kootenai - Madison - Minidoka - Nez Perce - Owyhee - Payette - Power - Twin Falls - Valley - Washington