Gravel, sand, silt, clay; Late Pleistocene glacio-alluvial and lacustrine deposits; Basin and Range, and Snake River Plain (IDQpug;0)

State	Idaho
Name	Gravel, sand, silt, clay; Late Pleistocene glacio-alluvial and lacustrine deposits; Basin and Range, and Snake River Plain
Geologic age	Late Pleistocene
Original map label	Qpug; Qp?g; Qpa
Comments	Melon gravel is Lake Bonneville outburst flood gravel, containing basalt boulders, in a giant gravel bar at the mouth of the Portneuf River valley. Qpug also includes glacial outwash, alluvial gravels and lacustrine sediments, deposited during high runoff of glacial melt-water, and interlayered with basalt flows of the Snake River Group.
Primary rock type	outwash
Secondary rock type	alluvium
Other rock types	lake or marine deposit (non-glacial); gravel; sand; silt; clay or mud
Lithologic constituents	Minor Unconsolidated > Fine-detrital > Clay (Lacustrine)clay in lava-dammed lakes Unconsolidated > Fine-detrital > Silt (Alluvial)alluvial slackwater silt Unconsolidated > Coarse-detrital > Sand (Glacial, outwash)interstitial sand in gravel and distal sand
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] Pierce, K.L., and Scott, W.E., 1982, Pleistocene episodes of alluvial-gravel deposition, southeastern Idaho: in Bonnicksen, Bill, and Breckenridge, R.M., eds, Cenozoic Geology of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology Bulletin 26, p. 685-702. Alt, D.D., and Hyndman, D.W., 1989, Roadside geology of Idaho: Missoula, Montana, Mountain Press Publishing Co., 393 p. Malde, H.E. and Powers, H.A., 1962, Upper Cenozoic stratigraphy of western Snake River Plain, Idaho: Geological Society of America Bulletin, v. 73, no. 10, p. 1197-1220. Malde, H.E., 1982, The Yahoo Clay, a lacustrine unit impounded by the McKinney basalt in the Sanke River Canyon near Bliss, Idaho: in Bonnichsen, Bill, and Breckenridge, R.M., eds., Cenozoic Geology of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology Bulletin 26, p. 617-628. 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. Carr, W.J. and Trimble, D.E., 1963, Geology of the American Falls quadrangle, Idaho: in Contributions to General Geology, 1960: U.S. Geological Survey Bulletin, 1121-G, p. G1-G44. [http://pubs.er.usgs.gov/publication/b1121G]
Geographic coverage	Bannock - Bingham - Blaine - Elmore - Gooding - Jerome - Owyhee - Power - Twin Falls