Mixed rocks

Intermingled, commonly highly sheared metasedimentary, metavolcanic, and igneous rocks. Includes serpentinite, altered gabbro, chert, siliceous phyllite, greenstone, and limestone
State Oregon
Name Mixed rocks
Geologic age Paleozoic to Mesozoic
Lithologic constituents
Metamorphic > Metaigneous > Greenstone (Greenschist)
Metamorphic > Metasedimentary (Greenschist)
Igneous > Plutonic > Gabbroic > Gabbro (Melange)
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Chemical > Chert (Bed)
Comments Includes blueschist. Pennsylvanian and Permian fusilinids have been identified in some blocks of limestone (M.K. Nestell, personal commun., 1993)

Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.

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.


Wolff, E.N., 1965, The geology of the northern half of the Caviness quadrangle, Oregon: Eugene, University of Oregon, Ph.D. dissertation, 214 p.

Swisher, C.C., Ach, J.A., and Hart, W.K., 1990, Laser fusion 40Ar/39Ar dating of the type Steens Mountain Basalt, southeastern Oregon, and the age of the Steens aeromagnetic polarity transition [abs.]: EOS, Transactions of American Geophysical Union, v. 17, no. 43, p. 1,296.

Prostka, H.J., 1968, Geologic map of the Ironside 15' quad, Oregon: Oregon Department of Geology and Mineral Industries, scale 1:62,500.

NGMDB product
Counties Baker - Malheur