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Late basalt (Holocene or upper Pleistocene)

Thin flows of scoriaceous, mostly olivine-bearing basalt in southeast Oregon; upper surfaces of flows characterized by blocky, spiny, or pahoehoe structures and by pressure ridges and tumuli, all essentially unmodified by erosion. Occurs at Diamond and Jordan Craters, the Devils Garden (Peterson, 1965), Lava Mountain, east flank of Green Mountain, and Pumice Desert
State Oregon
Name Late basalt (Holocene or upper Pleistocene)
Geologic age Late Pleistocene to Holocene
Primary rock type basalt
Secondary rock type
Other rock types
Lithologic constituents
Major
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)Mostly olivine basalt in southeast Oregon.
Map references
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Unit references
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Peterson, N.V., 1965, Hole-in-the-Ground--Fort Rock--Devils Garden area field trip, in Lunar Geological Field Conference Guide Book: Oregon Department of Geology and Mineral Industries Bulletin 57, p. 19-28
Walker, G.W. and Repenning, C.A., 1966, Geologic map of the west half of the Jordan Valley quadrangle, Malheur County, Oregon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-457, scale 1:250,000.
Greene, R.C., Walker, G.W., and Corcoran, R.E., 1972, Geologic map of the Burns quadrangle, Oregon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-680, scale 1:250,000.
Walker, G.W. and Repenning, C.A., 1965, Geologic map of Adel quadrangle, Lake, Harney, and Malheur Counties, Oregon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-446, scale 1:250,000.
Ferns, M.L., Evans, J.G., and Cummings, M.L., 1993a, Geologic map of the Mahogany Mountain 30 x 60 minute quadrangle, Malheur County, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-78, scale 1:100,000.
Walker, G.W., 1977, Geologic map of Oregon east of the 121st meridian: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-902, scale 1:500,000.
Ferns, M.L., 1992, Preliminary geologic map of the Saddle Butte quadrangle, Malheur County, Oregon: Oregon Department of Geology and Mineral Industries Open-File Map O-92-14, scale 1:24,000.
Ferns, M.L., 1992, Preliminary geologic map of the Wrangle Butte quadrangle, Malheur County, Oregon: Oregon Department of Geology and Mineral Industries Open-File Map O-92-15, scale 1:24,000.
Counties Harney - Malheur