Colebrooke Schist

Metamorphosed pelitic sedimentary rocks and subordinate metamorphosed submarine pillow lavas and pyroclastic beds of basaltic composition. Metamorphic age is Early Cretaceous (about 130 Ma), according to Coleman (1972), and protolith may be Jurassic or older in age
State Oregon
Name Colebrooke Schist
Geologic age Paleozoic or Mesozoic
Lithologic constituents
Metamorphic > Schist > Pelitic-schist (Greenschist)Pelitic schist transitional between greenschist and blueschist grade
Metamorphic > Metaigneous > Metavolcanic > MetabasaltIncludes metamorphosed pillow lavas, breccias, and pyroclastic rocks
Sedimentary > Chemical > Chert (Bed)
Comments Considered part of Pickett Peak Terrane by Blake and others (1985).

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

Coleman, R.G., 1972, The Colebrooke Schist of southwestern Oregon and its relation to the tectonic evolution of the region: U.S. Geological Survey Bulletin 1972, 61 p.

Blake, M.C., Jr., Engebretson, D.C., Jayko, A.S., and Jones, D.L., 1985, Tectonostratigraphic terranes in southwest Oregon, in Howell, D.G., ed., Tectonostratigraphic terranes of the circum-Pacific region: Circum-Pacific Council for Energy and Mineral Resources Earth Science Series, v. 1, p. 147-158.

Dott, R.H., Jr., 1971, Geology of the southwestern Oregon coast west of the 124th meridian: Oregon Department of Geology and Mineral Industries Bulletin 69, 63 p.

NGMDB product
Counties Curry