Ray Wells
Ray Wells is a research geologist in the Geology, Minerals, Energy, and Geophysics Science Center. Ray combines geologic mapping, structural geology and geophysical data to better understand the processes of crustal deformation, volcanism, and earthquake hazards of the Cascadia convergent margin in Oregon and Washington.
Ray Wells received his B.S. in Geological Science from Penn State, his M.S. from University of Oregon, and his Ph.D. from the University of California, Santa Cruz. He has 45 years of field experience documenting the geologic structure and earthquake hazards of the Cascadia convergent margin in Oregon and Washington, focusing primarily on the Coast Range, Seattle - Portland urban corridor, and the Columbia River Gorge.
Professional Experience
2020-current, Research Geologist, U.S. Geological Survey
2017-Research Associate, Portland State University, Portland, OR
2016-Research Geologist Emeritus, U.S. Geological Survey
1995-2013 Project Chief, Pacific Northwest Urban Corridor Geologic Mapping, USGS, Menlo Park, CA
1991-1996 Cascadia Regional Coordinator - USGS Deep Continental Surveys
1981-2016 Research Geologist, U.S. Geological Survey
1980 Geologist, Washington Division of Geology and Earth Resources
1978-1980 Research Assistant, University of California, Santa Cruz
1976-1977 Teaching Assistant, University of California, Santa Cruz
1975-1976 Geologist, U.S. Geological Survey
1974 Geological Field Assistant, Mobil Oil Corp., Tyee Basin
1972-1974 Teaching Assistant, University of Oregon
1971 Geological Field Assistant, Johns-Mannville Ltd, Stillwater Complex
Education and Certifications
Ph.D., Geology, University of California, Santa Cruz, 1982
M.S., Geology, University of Oregon, 1975
B.S., Geology, Art, Pennsylvania State University, 1972
Affiliations and Memberships*
1977 - Current, American Geophysical Union
1974 - Current, Geological Society of America
1990 - Current, Seismological Society of America (Fellow)
Bureau of Reclamation
Portland State University
Honors and Awards
Distinguished Service Award of the Department of the Interior
2017 Geological Society of America’s Geologic Mapping Award in honor of Florence Bascom
Geological Society of America George P. Woollard Award for outstanding contributions to geology through the application of the principles and techniques of geophysics
Science and Products
Filter Total Items: 108
Cenozoic evolution of the continental margin of Oregon and Washington
No abstract available.
Authors
P. D. Snavely, Ray E. Wells
Magnetic fabric, flow directions, and source area of the Lower Miocene Peach Springs Tuff in Arizona, California, and Nevada
We have used anisotropy of magnetic susceptibility (AMS) to define the flow fabric and possible source area of the Peach Springs Tuff, a widespread rhyolitic ash flow tuff in the Mojave Desert and Great Basin of California, Arizona, and Nevada. The tuff is an important stratigraphic marker from the Colorado Plateau to Barstow, California, a distance of 350 km; however, the location of...
Authors
John W. Hillhouse, Ray E. Wells
Off-fault ground ruptures in the Santa Cruz Mountains, California: Ridge-top spreading versus tectonic extension during the 1989 Loma Prieta earthquake
The Ms 7.1 Loma Prieta earthquake of 18 October 1989 produced abundant ground ruptures in an 8 by 4 km area along Summit Road and Skyland Ridge in the Santa Cruz Mountains. Predominantly extensional fissures formed a left-stepping, crudely en echelon pattern along ridges of the hanging-wall block southwest of the San Andreas fault, about 12 km northwest of the epicenter. The fissures are...
Authors
Daniel J. Ponti, Ray E. Wells
Geosciences
No abstract available.
Authors
Roger D. Borcherdt, N. C. Donovan, Donna Eberhart-Phillips, A. Michael, Paul A. Reasenberg, L. Dietz, W. Ellsworth, Daniel J. Ponti, Ray E. Wells, Ralph A. Haugerud, M. M. Clark, N. Timothy Hall
Paleomagnetic rotations and the Cenozoic tectonics of the Cascade Arc, Washington, Oregon, and California
Paleomagnetic results from Cenozoic (62–12 Ma) volcanic rocks of the Cascade arc and adjacent areas indicate that moderate to large clockwise rotations are an important component of the tectonic history of the arc. Two mechanisms of rotation are suggested by the regional pattern of paleomagnetic rotations. The progressive increase in rotation toward the coast in arc and forearc rocks...
Authors
Ray E. Wells
Mechanisms of Cenozoic tectonic rotation, Pacific Northwest Convergent Margin, U.S.A.
Large clockwise rotations (15–80°) are characteristic of Cenozoic volcanic and sedimentary rocks along the convergent margin of the northwestern United States. Abundant paleomagnetic data from 62–12 m.y. old rocks in forearc, arc, and backarc regions show that rotation increases with age and with proximity to the coast. Paleomagnetic and structural studies both support dextral shear as a...
Authors
Ray E. Wells
Preliminary map of fractures formed in the Summit Road-Skyland Ridge area during the Loma Prieta, California, earthquake of October 17, 1989
No abstract available.
Authors
Ray E. Wells, D.J. Ponti, M. M. Clark, Robert C. Bucknam, Karin E. Budding, T. E. Fumal, D. S. Harwood, K. R. Lajoie, J. J. Lienkaemper, M. N. Machette, C.S. Prentice, David P. Schwartz
Origin of the oceanic basalt basement of the Solomon Islands arc and its relationship to the Ontong Java Plateau-insights from Cenozoic plate motion models
Cenozoic global plate motion models based on a hotspot reference frame may provide a useful framework for analyzing the tectonic evolution of the Solomon Islands convergent margin. A postulated late Miocene collision of the Ontong Java Plateau (OJP) with a NE-facing arc is consistent with the predicted path of the OJP across the Pacific Basin and its Miocene arrival at the trench. Late...
Authors
Ray E. Wells
Correlation of Miocene flows of the Columbia River Basalt Group from the central Columbia River Plateau to the coast of Oregon and Washington
Nearly twenty flows of the Columbia River Basalt Group (CRBG) can be paleomagnetically and chemically correlated westward as far as 500 km from the Columbia Plateau in Washington, through the Columbia Gorge, to the Coast Range of Oregon and Washington. In the Coast Range near Cathlamet, Washington, the CRBG flow stratigraphy includes 10 flows of Grande Ronde Basalt (1 low-MgO R2 flow, 6...
Authors
Ray E. Wells, R.W. Simpson, R. D. Bentley, Melvin H. Beeson, Margaret T. Mangan, Thomas L. Wright
Paleomagnetism and tectonic rotation of the lower Miocene Peach Springs Tuff: Colorado Plateau, Arizona, to Barstow, California
We have determined remanent magnetization directions of the lower Miocene Peach Springs Tuff at 41 localities in western Arizona and southeastern California. An unusual northeast and shallow magnetization direction confirms the proposed geologic correlation of isolated outcrops of the tuff from the Colorado Plateau to Barstow, California, a distance of 350 km. The Peach Springs Tuff was...
Authors
Ray E. Wells, John W. Hillhouse
The relative contribution of accretion, shear, and extension to Cenozoic tectonic rotation in the Pacific Northwest
Large Cenozoic clockwise rotations defined by paleomagnetic data are an established fact in the Pacific Northwest, and many tectonic models have been proposed to explain them, including (1) rotation of accreted oceanic microplates during docking, (2) dextral shear between North America and northward-moving oceanic plates to the west, and (3) microplate rotation in front of an expanding...
Authors
Ray E. Wells, Paul L. Heller
Paleomagnetism of Middle Tertiary volcanic rocks from the Western Cascade Series, northern California
The Western Cascade Series (WCS) is a 3.5‐km‐thick, crudely homoclinal (east dipping) calcalkaline volcanic sequence of mid‐Oligocene to early Miocene age that crops out near the southern tip of the Cascade Range in northern California. The mean direction of remanent magnetization in the WCS is D, 4.9°; I, 57.6° (N, 53; k, 14.4; α95, 5.3°). When compared to a reference direction for the...
Authors
Myrl E. Beck, Russell F. Burmester, Douglas E. Craig, C. Sherman Grommé, Ray E. Wells
Science and Products
Filter Total Items: 108
Cenozoic evolution of the continental margin of Oregon and Washington
No abstract available.
Authors
P. D. Snavely, Ray E. Wells
Magnetic fabric, flow directions, and source area of the Lower Miocene Peach Springs Tuff in Arizona, California, and Nevada
We have used anisotropy of magnetic susceptibility (AMS) to define the flow fabric and possible source area of the Peach Springs Tuff, a widespread rhyolitic ash flow tuff in the Mojave Desert and Great Basin of California, Arizona, and Nevada. The tuff is an important stratigraphic marker from the Colorado Plateau to Barstow, California, a distance of 350 km; however, the location of...
Authors
John W. Hillhouse, Ray E. Wells
Off-fault ground ruptures in the Santa Cruz Mountains, California: Ridge-top spreading versus tectonic extension during the 1989 Loma Prieta earthquake
The Ms 7.1 Loma Prieta earthquake of 18 October 1989 produced abundant ground ruptures in an 8 by 4 km area along Summit Road and Skyland Ridge in the Santa Cruz Mountains. Predominantly extensional fissures formed a left-stepping, crudely en echelon pattern along ridges of the hanging-wall block southwest of the San Andreas fault, about 12 km northwest of the epicenter. The fissures are...
Authors
Daniel J. Ponti, Ray E. Wells
Geosciences
No abstract available.
Authors
Roger D. Borcherdt, N. C. Donovan, Donna Eberhart-Phillips, A. Michael, Paul A. Reasenberg, L. Dietz, W. Ellsworth, Daniel J. Ponti, Ray E. Wells, Ralph A. Haugerud, M. M. Clark, N. Timothy Hall
Paleomagnetic rotations and the Cenozoic tectonics of the Cascade Arc, Washington, Oregon, and California
Paleomagnetic results from Cenozoic (62–12 Ma) volcanic rocks of the Cascade arc and adjacent areas indicate that moderate to large clockwise rotations are an important component of the tectonic history of the arc. Two mechanisms of rotation are suggested by the regional pattern of paleomagnetic rotations. The progressive increase in rotation toward the coast in arc and forearc rocks...
Authors
Ray E. Wells
Mechanisms of Cenozoic tectonic rotation, Pacific Northwest Convergent Margin, U.S.A.
Large clockwise rotations (15–80°) are characteristic of Cenozoic volcanic and sedimentary rocks along the convergent margin of the northwestern United States. Abundant paleomagnetic data from 62–12 m.y. old rocks in forearc, arc, and backarc regions show that rotation increases with age and with proximity to the coast. Paleomagnetic and structural studies both support dextral shear as a...
Authors
Ray E. Wells
Preliminary map of fractures formed in the Summit Road-Skyland Ridge area during the Loma Prieta, California, earthquake of October 17, 1989
No abstract available.
Authors
Ray E. Wells, D.J. Ponti, M. M. Clark, Robert C. Bucknam, Karin E. Budding, T. E. Fumal, D. S. Harwood, K. R. Lajoie, J. J. Lienkaemper, M. N. Machette, C.S. Prentice, David P. Schwartz
Origin of the oceanic basalt basement of the Solomon Islands arc and its relationship to the Ontong Java Plateau-insights from Cenozoic plate motion models
Cenozoic global plate motion models based on a hotspot reference frame may provide a useful framework for analyzing the tectonic evolution of the Solomon Islands convergent margin. A postulated late Miocene collision of the Ontong Java Plateau (OJP) with a NE-facing arc is consistent with the predicted path of the OJP across the Pacific Basin and its Miocene arrival at the trench. Late...
Authors
Ray E. Wells
Correlation of Miocene flows of the Columbia River Basalt Group from the central Columbia River Plateau to the coast of Oregon and Washington
Nearly twenty flows of the Columbia River Basalt Group (CRBG) can be paleomagnetically and chemically correlated westward as far as 500 km from the Columbia Plateau in Washington, through the Columbia Gorge, to the Coast Range of Oregon and Washington. In the Coast Range near Cathlamet, Washington, the CRBG flow stratigraphy includes 10 flows of Grande Ronde Basalt (1 low-MgO R2 flow, 6...
Authors
Ray E. Wells, R.W. Simpson, R. D. Bentley, Melvin H. Beeson, Margaret T. Mangan, Thomas L. Wright
Paleomagnetism and tectonic rotation of the lower Miocene Peach Springs Tuff: Colorado Plateau, Arizona, to Barstow, California
We have determined remanent magnetization directions of the lower Miocene Peach Springs Tuff at 41 localities in western Arizona and southeastern California. An unusual northeast and shallow magnetization direction confirms the proposed geologic correlation of isolated outcrops of the tuff from the Colorado Plateau to Barstow, California, a distance of 350 km. The Peach Springs Tuff was...
Authors
Ray E. Wells, John W. Hillhouse
The relative contribution of accretion, shear, and extension to Cenozoic tectonic rotation in the Pacific Northwest
Large Cenozoic clockwise rotations defined by paleomagnetic data are an established fact in the Pacific Northwest, and many tectonic models have been proposed to explain them, including (1) rotation of accreted oceanic microplates during docking, (2) dextral shear between North America and northward-moving oceanic plates to the west, and (3) microplate rotation in front of an expanding...
Authors
Ray E. Wells, Paul L. Heller
Paleomagnetism of Middle Tertiary volcanic rocks from the Western Cascade Series, northern California
The Western Cascade Series (WCS) is a 3.5‐km‐thick, crudely homoclinal (east dipping) calcalkaline volcanic sequence of mid‐Oligocene to early Miocene age that crops out near the southern tip of the Cascade Range in northern California. The mean direction of remanent magnetization in the WCS is D, 4.9°; I, 57.6° (N, 53; k, 14.4; α95, 5.3°). When compared to a reference direction for the...
Authors
Myrl E. Beck, Russell F. Burmester, Douglas E. Craig, C. Sherman Grommé, Ray E. Wells
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government