Silt, clay, and diatomite; Middle Pleistocene lacustrine sediments of lava-dammed lakes; western Snake River Plain (IDQpmd;0)

State	Idaho
Name	Silt, clay, and diatomite; Middle Pleistocene lacustrine sediments of lava-dammed lakes; western Snake River Plain
Geologic age	Middle Pleistocene
Original map label	Qpmd
Comments	Lake Idaho sediments: lacustrine silt, clay and diatomite, sand, inter-tongued with lenticular basalt flows and basaltic pyroclastic debris. Lacustrine deposits inter-tongue with alluvial gravel and sand, deposited by streams that fed lava-dammed lakes that formed along channels eroded into Glenns Ferry strata, on the western Snake River Plain.
Primary rock type	lake or marine deposit (non-glacial)
Secondary rock type	alluvium
Other rock types	silt; clay or mud; diatomite; sand; gravel
Lithologic constituents	Major Unconsolidated > Fine-detrital > Clay (Lacustrine)clay in lava-dammed lake beds Unconsolidated > Fine-detrital > Silt (Lacustrine)silt in lava-dammed lake beds and floodplains Incidental Unconsolidated > Coarse-detrital > Gravel (Lacustrine)alluvial well-sorted pebble gravel Unconsolidated > Coarse-detrital > Sand (Lacustrine)alluvial fine sand beds Sedimentary > Chemical > Diatomite (Bed)lacustrine diatomite beds
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. 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. 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.
Geographic coverage	Elmore - Gooding - Owyhee - Twin Falls