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Sedimentary rocks, partly metamorphosed (Triassic and Paleozoic)

Poorly bedded argillite, chert, phyllite, phyllitic quartzite, calc-phyllite, impure limestone, and marble. In places rocks are strongly foliated. Sparse fossils (Fusilina, corals, and crinoids) indicate that the unit includes rocks of Leonardian, Ochoan, and Late Triassic age (OR084). Includes Elkhorn Ridge Argillite (OR035), Mesozoic and Paleozoic sedimentary rocks of Brown and Thayer (OR008), and the Permian Coyote Butte Formation (OR085). In Baker County includes "sedimentary and volcanic rocks" (MzPza) of Brooks and others (OR039) and metamorphosed sedimentary and minor volcaniclastic rocks containing mineral assemblages indicative of quartz-albite-muscovite-chlorite subfacies and quartz-albite-epidote-biotite subfacies of the greenschist facies. In Jefferson and Wasco Counties north of Prineville, includes "phyllite and sedimentary rocks " of Swanson (OR031). Includes part of the Burnt River Schist (OR035; OR081) and volcaniclastic facies of several metavolcanic units of Permian and Late Triassic age. Not on State map (OR001) in area of La Grande 100K quadrangle, butmapped in OR291 as Elkhorn Ridge Argillite (Triassic Permian, Pennsylvannian, and Devonian?)
State Oregon
Name Sedimentary rocks, partly metamorphosed (Triassic and Paleozoic)
Geologic age Paleozoic to Triassic
Comments Burnt River Schist encloses Nelson marble (unit TRPzsn), which was assigned a Late to Middle Triassic age based on conodonts (OR191). The Burnt River Schist is intruded by a 230 Ma (Middle Triassic) diorite (OR190).
Primary rock type argillite
Secondary rock type chert
Other rock types pelitic schist
Lithologic constituents
Major
Metamorphic > Argillite (Bed)
Sedimentary > Chemical > Chert (Bed)Contains argillite, chert, phyllite, phyllitic quartzite, calc-phyllite, impure limestone, and marble; metamorphosed in places.
Minor
Sedimentary > Clastic > Sandstone > Arenite (Bed)
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Carbonate > Limestone (Lense)
Metamorphic > Metasedimentary (Greenschist)
Metamorphic > Marble
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.
Brown, C.E. and Thayer, T.P., 1966, Geologic map of the Canyon City quadrangle, northeastern Oregon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-447, scale 1:250,000.
Prostka, H.J., 1962, Geology of the Sparta quadrangle, Oregon: Oregon Department of Geology and Mineral Industries Geologic Map Series GMS-1, scale 1:62,500.
Swanson, D.A., 1969a, Reconnaissance geologic map of the east half of the Bend quadrangle, Crook, Wheeler, Jefferson, Wasco, , and Deschutes Counties, Oregon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-568, scale 1:250,000.
Brooks, H.C., McIntyre, J.R., and Walker, G.W., 1976, Geology of the Oregon part of the Baker 1o by 2o quadrangle: Oregon Department of Geology and Mineral Industries Geologic Map Series GMS-7, scale 1:250,000.
Walker, G.W., 1979, Reconnaissance geologic map of the Oregon part of the Grangeville quadrangle, Baker, Union, Umatilla, and Wallowa Counties, Oregon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-1116, scale 1;250,000
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.
Robinson, P.T., 1975, Reconnaissance geologic map of the John Day Formation in the southwestern part of the Blue Mountains and adjacent areas, north-central Oregon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-872, scale 1:125,000.
Thayer, T.P., 1963, The Canyon Mountain complex, Oregon, and the alpine mafic magma stem: U.S. Geological Survey Professional Paper 475-C, p. C82-C85.
Thayer, T., P., 1977, The Canyon Mountain Complex, Oregon, and some problems of ophiolites, in Coleman, R.G. and Irwin, W.P., North American Ophiolites: Oregon Department of Geology and Mineral Industries Bulletin 95, p. 93-105.
Wolff, E.N., 1965, The geology of the northern half of the Caviness quadrangle, Oregon: Eugene, University of Oregon, Ph.D. dissertation, 214 p.
Ashley, R.P., 1967, Metamorphic petrology and structure of the Burnt River Canyon area, northeastern Oregon: Stanford, California, Stanford University, Ph.D. dissertation, 236 p.
Brooks, H.C., Ferns, M.L., Wheeler, G.R., and Avery, D.G., 1983, Geology and gold deposits map of the northeast quarter of the Bates quadrangle, Baker and Grant Counties, Oregon: Oregon Department of Geology and Mineral Industries Geologic Map Series GMS-7, scale 1:24,000.
Ferns, M.L., Brooks, H.C., and Avery, D.G., 1983, Geology and gold deposits of the Greenhorn quadrangle, Baker and Grant Counties, Oregon: Oregon Department of Geology and Mineral Industries Geologic Map Series GMS-28, scale 1: 24,000.
Bostwick, D.A., and Koch, G.S., Jr., 1962, Permian and Triassic rocks of northeastern Oregon: Geological Society of America Bulletin, v. 73, p. 419-422.
Merriam, C.W. and Berthiaume, S.A., 1943, Late Paleozoic formations of central Oregon: Geological Society of America Bulletin, v. 54, p. 145-172.
Brooks, H.C., 2006, Preliminary geologic map of the Mormon Basin quadrangle, Baker County, Oregon: Oregon Department of Geology and Mineral Industries Open-File Map O-06-25, scale 1:24,000.
Brooks, H.C., Ferns, M.L., and Mullen, A.D., 1982, Geology and mineral deposits of the Granite quadrangle, Grant County, Oregon: Oregon Department of Geology and Mineral Industries Geologic Map Series GMS-25, scale 1:24,000.
Ferns, M.L., Brooks, H.C., and Avery, D.G., 1983, Geology and gold deposits map of the Greenhorn quadrangle, Baker and Grant Counties, Oregon: Oregon Department of Geology and Mineral Industries Geologic Map Series GMS-28, scale 1:24,000.
Evans, J.G., Geologic map of the Dooley Mountain quadrangle, Baker County, Oregon: U.S. Geological Survey Geological Quadrangle GQ-1694, scale 1: 24,000.
Ferns, M.L. and Brooks, H.C., 1987, Geology and mineral resources map of the Elkhorn Peak quadrangle, Baker County, Oregon: Oregon Department of Geology and Mineral Industries Geologican Map Series GMS-41, scale 1:24,000.
Ferns, M.L., Brooks, H.C., and Wheeler, G.R., 1984, Geology and gold deposits of the Bates quadrangle, Grant County, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-31, scale 1:24,000.
Ferns, M.L., Brooks, H.C., and Ducette, J., 1982, Geology and mineral resources map of the Mt. Ireland quadrangle, Baker and Grant Counties, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series, GMS-22, scale 1:24,000.
Brooks, H.C., Ferns, M.L., Wheeler, G.R., and Avery, D.G., 1983, Geology and gold deposits map of the northeast quarter of the Bates quadrangle, Baker and Grant Counties, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-29, scale 1:24,000
Brooks, H.C., Ferns, M.L., Coward, R.I., Paul, E.K., and Nunlist, M., 1982, Geology and gold deposits map of the Bourne quadrangle, Baker and Grant Counties, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-19, scale 1:24,000.
Brooks, H.C., 1979, Geologic map of the Oregon part of the Mineral quadrangle: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-12, scale 1:62,500.
Evans, J.G., 1989, Geologic map of the Desolation Butte quadrangle, Grant and Umatilla Counties, Oregon: U.S. Geological Survey Geologic Quadrangle GQ-1654, scale 1:62,500.
Brooks, H.C. and Ferns, M.L., 1979, Geologic map of the Bullrun Rock quadrangle, Baker and Grant Counties, Oregon: Oregon Department of Geology and Mineral Industries Open-File Map O-79-6, scale 1:24,000.
Lees, K.R., 1994, Magmatic and tectonic changes through time in the Neogene volcanic rocks of the Vale area, Oregon, northwestern USA: Milton Keynes, U.K., The Open University, Ph.D. dissertation 284 p.
Hart, W.K. and Carlson, R.W., 1985, Distribution and geopchronology of Steens Mountain type basalts from the northwestern Great Basin: Isochron/West, no. 43, p. 5-10.
Hart, W.K., Carlson, R.W., and Mosher, S.A., 1989, Petrogenesis of the Pueblo Mountains Basalt, southeastern Oregon and northwestern Nevada, in Reidel, S.P. and Hooper, P.R., eds., Volcanism and tectonism in the Columbia River flood-basalt province: Geological Society of America Special Paper 239, p. 105-111.
Baksi, A.K., Hall, C.M., and York, Derek, 1991, Laser 40Ar/39Ar dating studies on submilligram whole-rock basalt samples: the age of the Steens Mountain geomagnetic polarity transition (revisited ): Earth and Planetary Science Letters, v. 104, p. 292-298.
Evernden, J.F., Savage, D.E., Curtis, G.H., and James, G.T., 1964, Potassium-argon dates and the Cenozoic mammalian chronology of North America: American Journal of Science, v. 262, p. 145-198.
Walker, N.W., 1986, U/Pb geochronologic and petrologic studies in the Blue Mountains terrane, northeastern Oregon and westernmost-central Idaho: Implications for pre-Tertiary evolution: Santa Barbara, University of California, Ph.D. dissertation, 214 p.
Cummings, M.L., Evans, J.G., Ferns, M.L., and Lees, K.R., 2000, Evolution of the middle Miocene syntectonic Oregon-Idaho graben, southeast Oregon: Geological Society of America Bulletin, v. 112, no. 5, p. 668-682.
Evans, J.G., Geologic map of the Beaverdam Creek quadrangle, Baker County, Oregon: U.S. Geological Survey Miscellaneous Field Studies Map MF-2299, scale 1:24,000.
Evans, J.G., 1993, Geologic map of the Brannan Gulch quadrangle, Baker County, Oregon: U.S. Geological Survey Geological Quadrangle GQ-1744, scale 1:24,000.
Evans, J.G., 1993, unpub. mapping, Unity Reservoir quadrangle, Baker County Oregon.
Evans, J.G., 1994, unpub. mapping, Hereford quadrangle, Baker County, Oregon.
Ferns, M.L., Brooks, H.C., and Avery, D.G., 1983, Geology and gold deposits map of the Greenhorn Quadrangle, Baker and Grant Counties, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-28, scale 1:24,000.
Whitsun, N.W., 1988, Geochemical stratigraphy of the Dooley Rhyolite Breccia and Tertiary basalts in the Dooley Mountain quadrangle, Oregon: Portland, Oregon, Portland State University, master's thesis, 122 p.
Ferns, M.L., Madin, I.P., and Taubeneck, W.H., 2001, Reconnaissance geologic map of the La Grande 30' x 60' quadrangle, Baker, Grant, Umatilla, and Union Counties, Oregon: Oregon Department of Geology and Mineral Industries Reconnaissance Map Series RMS-1, 52 p., scale 1:100,000.
Counties Baker - Crook - Grant - Harney - Jefferson - Malheur - Wallowa - Wasco - Wheeler