John Day Formation of east-central Oregon (ORTsfj;0)

State	Oregon
Name	John Day Formation of east-central Oregon
Geologic age	Late Eocene to Early Miocene
Lithologic constituents	Major Sedimentary > Clastic > Mixed-clastic > Sandstone-mudstone (Bed)No lithologies provided in OR001
Comments	Unit in La Grande 30' x 60' quadrangle (OR291), reinterpreted as part of Oligocene and early Miocene Tower Mountain volcanic field with the main vent a 14-km-wide caldera (Tower Mountain caldera). Vent-filling ash-flow tuff is intruded by dacite and rhyolite plugs and dikes and ringed by a belt of rhyolite domes and flows. The caldera margin is coincident with prominent gravity and aeromagnetic anomalies. The volcanic field contains 18 map units that range in composition from basalt to rhyolite. Unit in Umatilla River Basin (OR292) is reinterpreted as Herren Formation, consisting mainly of interbedded arkosic sandstone, mudstone, and carbonaceous shale. Also contains micacaous sandstone and siltstone. Section on East Birch Creek is interpreted as a deltaic sequence that coarsens upward. Leaf fossils are abundant locally and collections from Birch and Pearson Creeks indicate a late Paleocene to early Eocene age.
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. https://pubs.er.usgs.gov/publication/i447 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. https://pubs.er.usgs.gov/publication/i568 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., 1973, Reconnaissance geologic map of the Pendleton quadrangle, Oregon and Washington: U.S. Geological Survey Miscellaneus Geologic Investigations Map I-727, scale 1:250,000. https://pubs.er.usgs.gov/publication/i727 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. https://pubs.er.usgs.gov/publication/i902 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. https://pubs.er.usgs.gov/publication/i872 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. 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 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. https://pubs.er.usgs.gov/publication/gq1744 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. 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. Ferns, M.L., McConnell, V.S., and Madin, I.P., in prep., Geology of the Umatilla River Basin, Morrow, Umatilla, and Union Counties, Oregon: Oregon Department of Geology and Mineral Industries Open-File Report, 66 p., scale 1:100,000. Ferns, M.L., 1999, Geologic map of the Fly Valley quadrangle, Union County, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-113, scale 1:24,000. Madin, I.P., 1998, Geologic map of the Tucker Flat quadrangle, Union and Baker Counties, Oregon: Oregon Department of Geology and Mineral Industries Geological map Series GMS-110, scale 1;24,000. Madin, I.P. and Taubeneck, W.H., 2003, Geologic map of the Amnthony Buttes quadrangle, Union and Baker Counties, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-107, scale 1:24,000. Ferns, M.L. and Taubeneck, W.H., 1994, Geology and mineral resources of the Limber Jim Creek quadrangle, Union County, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-82, scale 1:24,000. Waters, A.C., 1968, Reconnaissance geologic map of the Madras quadrangle, Jeffereson and Wasco Counties, Oregon" U.S. Geological Survey Miscellaneous Geological Investigations Map I-555, scale 1;125,000. https://pubs.er.usgs.gov/publication/i555
NGMDB product	NGMDB product page for 16259
Counties	Baker - Crook - Deschutes - Gilliam - Grant - Jefferson - Morrow - Umatilla - Union - Wasco - Wheeler

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.

https://pubs.er.usgs.gov/publication/i447

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.

https://pubs.er.usgs.gov/publication/i568

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., 1973, Reconnaissance geologic map of the Pendleton quadrangle, Oregon and Washington: U.S. Geological Survey Miscellaneus Geologic Investigations Map I-727, scale 1:250,000.

https://pubs.er.usgs.gov/publication/i727

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.

https://pubs.er.usgs.gov/publication/i902

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.

https://pubs.er.usgs.gov/publication/i872

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.

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

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.

https://pubs.er.usgs.gov/publication/gq1744

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.

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.

Ferns, M.L., McConnell, V.S., and Madin, I.P., in prep., Geology of the Umatilla River Basin, Morrow, Umatilla, and Union Counties, Oregon: Oregon Department of Geology and Mineral Industries Open-File Report, 66 p., scale 1:100,000.

Ferns, M.L., 1999, Geologic map of the Fly Valley quadrangle, Union County, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-113, scale 1:24,000.

Madin, I.P., 1998, Geologic map of the Tucker Flat quadrangle, Union and Baker Counties, Oregon: Oregon Department of Geology and Mineral Industries Geological map Series GMS-110, scale 1;24,000.

Madin, I.P. and Taubeneck, W.H., 2003, Geologic map of the Amnthony Buttes quadrangle, Union and Baker Counties, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-107, scale 1:24,000.

Ferns, M.L. and Taubeneck, W.H., 1994, Geology and mineral resources of the Limber Jim Creek quadrangle, Union County, Oregon: Oregon Department of Geology and Mineral Industries Geological Map Series GMS-82, scale 1:24,000.

Waters, A.C., 1968, Reconnaissance geologic map of the Madras quadrangle, Jeffereson and Wasco Counties, Oregon" U.S. Geological Survey Miscellaneous Geological Investigations Map I-555, scale 1;125,000.

https://pubs.er.usgs.gov/publication/i555