Ryan Crow is a Research Geologist at the Geology, Minerals, Energy, and Geophysics Science Center, in Flagstaff, Arizona. He did his graduate work at the University of New Mexico, where he studied the tectonic geomorphology of the Grand Canyon. Coming to the USGS in 2014 as a Mendenhall Postdoc, he focused on the landscape evolution of the lower Colorado River corridor and the Colorado River.
Ryan is pursuing a better understanding of the processes modulating Earth’s surface in the southwestern U.S. He is currently interested in integrating analytical and field-based geologic mapping approaches to understand the effect of fluvial systems, tectonics, exogenous events, and climate on landscape evolution. To arrive at a holistic view, he employs a multi-disciplinary approach utilizing a diverse range of geologic, geochronologic, tectonic, geophysical, and geochemical datasets, integrated through custom-designed geographic information system (GIS) tools.
His current work is focused on:
- Surficial geologic mapping along the lower Colorado River (CA, NV, and AZ)
- Effects of epeirogenic uplift and faulting on river systems and landscapes in the Grand Canyon, Zion Plateau, and Lake Mead areas (AZ, UT, and NV)
- Mantle evolution under and around the Colorado Plateau as constrained with geochemistry, geochronology, and mantle tomography (AZ, UT, NM, and CO)
- The processes and timing of Colorado River inception and evolution in and downstream from Grand Canyon (CA, NV, and AZ)
- Geomorphic effect of lava damming in Grand Canyon, AZ
Professional Experience
2018 to current, Research Geologist, U.S. Geological Survey, Flagstaff, AZ
2014 to 2018, Mendenhall Postdoctoral Scholar / Research Geologist, U.S. Geological Survey, Flagstaff, AZ
2013 to 2014, Postdoctoral Scholar, University of New Mexico, Albuquerque, NM
2002 to 2005, Profession Research Associate, University of Colorado, Boulder, CO
1999 to 2002, Peace Corps Volunteer, Guatemala
Education and Certifications
Ph.D., 2012, University of New Mexico
M.S., 2008, University of New Mexico
B.A.,1999, University of Colorado
Affiliations and Memberships*
2003-present, Geological Society of America
2005-present, American Geophysical Union
Science and Products
Geologic Mapping of the Lower Colorado River System
This is a comprehensive scientific investigation of the geologic history and framework of the lower Colorado River. We are using geologic mapping in combination with stratigraphic, geochronologic, and geophysical studies to develop a holistic understanding of the river’s origin, the structural history of the landscape through which it flows, and the stratigraphic and geomorphic consequences of the...
Digital database for the geologic map of the Vidal, California, and Parker SW, California-Arizona quadrangles
This geologic database is a digitized version of the original 1:24,000-scale analog geologic map titled "Geologic map of the Vidal, California, and Parker SW, California-Arizona quadrangles", published by the U.S. Geological Survey (USGS) in 1980. The map area straddles the Arizona-California border, and is located approximately 9.0 km (5.6 mi) west-southwest of Parker, CA, immediately south of th
Digital database for the geologic map of the Parker NW, Parker, and parts of the Whipple Mountains SW and Whipple Wash quadrangles, California and Arizona
This geologic database is a digitized version of the 1:24,000-scale original analog geologic map titled "Geologic map of the Parker NW, Parker, and parts of the Whipple Mountains SW and Whipple Wash quadrangles, California and Arizona", published by the U.S. Geological Survey (USGS) in 1980. The map area straddles the Arizona-California border and includes the community of Parker, AZ, and the sout
Digital data documenting the evolution of Miocene normal and dextral faulting in the lower Colorado River region near Blythe, California, USA
These datasets provide the measurements and analytical data used to describe the evolution of Neogene faulting near Blythe, California. The data include structural measurements and results from Ar-Ar and U-Pb geochronology that address the research questions of the associated publication. Structural measurement datasets provide fault surface kinematic measurements and tabulations of structural dat
Digital database of geologic units, contacts, and faults for Mineral Resource Potential Map of the Turtle Mountains Wilderness Study Area, San Bernardino County, California (U.S. Geological Survey Bulletin 1713-B, 1988, Plate 1)
This map geodatabase digitally represents the general distribution of bedrock geologic map units in the Turtle Mountains area, California, as portrayed in Plate 1 of USGS Bulletin 1713-B, Mineral resources of the Turtle Mountains Wilderness Study Area, San Bernardino County, California (1988), https://doi.org/10.3133/b1713B. The map covers parts of the Rice, Turtle Mountains, and Savahia Peak 15’
Surficial geologic map of the Spirit Mountain SE and part of the Spirit Mountain NE 7.5' quadrangles, Nevada and Arizona
This geologic map includes a trove of stratigraphic and geomorphic information that chronicles the inception and evolution of the lower Colorado River. The map area is located near the south end of the Lake Mead National Recreation Area about 80 km (50 mi) downstream from Hoover Dam. It spans parts of northwestern Arizona and southern Nevada near the south end of Cottonwood Valley. The map include
Geologic map of the Castle Rock 7.5' quadrangle, Arizona and California
The Castle Rock quadrangle is in the northeast corner of Chemehuevi Valley, California and Arizona. It includes the Colorado River’s entrance to the valley at the mouth of Topock Gorge and the northern outskirts of Lake Havasu City, Arizona, and the Chemehuevi Indian Tribe community of Havasu Lake, California. The map includes large parts of the Chemehuevi Indian Reservation and the Havasu Nationa
Geologic map of the Castle Rock 7.5' quadrangle, Arizona and California
The Castle Rock quadrangle is in the northeast corner of Chemehuevi Valley, California and Arizona. It includes the Colorado River’s entrance to the valley at the mouth of Topock Gorge and the northern outskirts of Lake Havasu City, Arizona, and the Chemehuevi Indian Tribe community of Havasu Lake, California. The map includes large parts of the Chemehuevi Indian Reservation and the Havasu Nationa
Filter Total Items: 16
Evolution of Miocene normal and dextral faulting in the lower Colorado River region near Blythe, California, USA
The evolution of strain in nascent continental plate boundaries commonly involves distributed deformation and transitions between different styles of deformation as the plate boundary matures. Distributed NW-striking faults, many with km-scale right-lateral separation, are prevalent near Blythe, California, and have been variably interpreted to have accommodated either Middle Miocene NE-SW extensi
Authors
Skyler Pendleton Mavor, Scott E. K. Bennett, Ryan S. Crow, John S. Singleton, Victoria Langenheim, Daniel F. Stockli, Mark E. Stelten, Timothy Brickey Sr., Paul J. Umhoefer, L. Sue Beard
Late Cretaceous time-transgressive onset of Laramide arch exhumation and basin subsidence across northern Arizona−New Mexico, USA, and the role of a dehydrating Farallon flat slab
Spatiotemporal constraints for Late Cretaceous tectonism across the Colorado Plateau and southern Rocky Mountains (northern Arizona−New Mexico, USA) are interpreted in regards to Laramide orogenic mechanisms. Onset of Laramide arch development is estimated from cooling recorded in representative thermochronologic samples in a three-step process of initial forward models, secondary HeFTy inverse mo
Authors
Jacob Thacker, Karl Karlstrom, Shari Kelley, Ryan S. Crow, Jerry Kendall
Fault-influenced incision in western Grand Canyon, Arizona U.S.A.
Preliminary interpretation of new and updated incision rates in western Grand Canyon shows the effects of Quaternary faulting, which dampens river incision rates in the footwalls and amplifies them in the hanging walls of normal faults. In the reach between Lava Falls and Diamond Creek in western Grand Canyon, about 178 to 225 river miles downstream from Lees Ferry, the river crosses the neotecton
Authors
Ryan S. Crow, Karl Karlstrom, Warren Sharp, Victor Polyak, Yemane Asmerom, Laura Crossey
Redefining the age of the lower Colorado River, southwestern United States: Reply
Crow et al. (2021) report new geochronologic and paleomagnetic data indicating that the lower Colorado River (CR) became integrated to the proto–Gulf of California (GOC) between 4.8 and 4.62 Ma instead of at ca. 5.3 Ma, as suggested by Dorsey et al. (2007, 2018). Dorsey et al. (2021) dispute this new chronology but offer no alternative explanation for one of the key data sets requiring it, new det
Authors
Ryan S. Crow, Jonathan Schwing, Karl Karlstrom, Matt Heizler, Philip Pearthree, Kyle House, Shannon Dulin, Susane Janecke, Mark E. Stelten, Laurie Crossey
Redefining the age of the lower Colorado River, southwestern United States
Sanidine dating and magnetostratigraphy constrain the timing of integration of the lower Colorado River (southwestern United States and northern Mexico) with the evolving Gulf of California. The Colorado River arrived at Cottonwood Valley (Nevada and Arizona) after 5.24 Ma (during or after the Thvera subchron). The river reached the proto–Gulf of California once between 4.80 and 4.63 Ma (during th
Authors
Ryan S. Crow, J. Schwing, K. E. Karlstrom, M. Heizler, P. A. Pearthree, P. K. House, S. Dulin, S. U. Janecke, Mark E. Stelten, L. J. Crossey
Post-12 Ma deformation of the lower Colorado River corridor, southwestern USA: Implications for diffuse transtension and the Bouse Formation
Structural evidence presented here documents that deformation was ongoing within the lower Colorado River corridor (southwestern USA) during and after the latest Miocene Epoch, postdating large-magnitude extension and metamorphic core complex formation. Geometric and kinematic data collected on faults in key geologic units constrain the timing of deformation in relation to the age of the Bouse For
Authors
Jacob Thacker, Karl Karlstrom, Laura Crossey, Ryan S. Crow, Colleen Cassidy, L. Sue Beard, John Singleton, Evan Strickland, Nikki Seymour, Michael Wyatt
The Bouse Formation: A controversial Neogene archive of the evolving Colorado River: A scientific drilling workshop report (Feb. 28-March 3, 2019-Bluewater Resort, Parker, Arizona, USA
Neogene deposits of the lower Colorado River valley, especially the Miocene(?) and early Pliocene Bouse Formation, have been the focus of intense debate regarding the early paleoenvironmental history of this important continental-scale river system in southwestern North America and its integration with the proto-Gulf of California. Fine-grained units within these Neogene deposits also hold a promi
Authors
Andrew S. Cohen, Colleen Cassidy, Ryan S. Crow, Jordon Bright, Laura Crossey, Rebecca Dorsey, Brian F. Gootee, Kyle House, Keith A. Howard, Karl Karlstrom, Philip Pearthree
Insights into post-Miocene uplift of the western margin of the Colorado Plateau from the stratigraphic record of the lower Colorado River
The spatial and temporal distribution of Pliocene to Holocene Colorado River deposits (southwestern USA and northwestern Mexico) form a primary data set that records the evolution of a continental-scale river system and helps to delineate and quantify the magnitude of regional deformation. We focus in particular on the age and distribution of ancestral Colorado River deposits from field observatio
Authors
Ryan S. Crow, Keith A. Howard, L. Sue Beard, Phil Pearthree, Kyle House, Karl Karlstrom, Lisa Peters, William C. McIntosh, Colleen Cassidy, Tracey J. Felger, Debra Block
A river is born: Highlights of the geologic evolution of the Colorado River extensional corridor and its river: A field guide honoring the life and legacy of Warren Hamilton
The Colorado River extensional corridor, which stretched by a factor of 2 in the Miocene, left a series of lowland basins and intervening bedrock ranges that, at the dawn of the Pliocene, were flooded by Colorado River water newly diverted from the Colorado Plateau through Grand Canyon. This water and subsequent sediment gave birth, through a series of overflowing lakes, to an integrated Colorado
Authors
Keith A. Howard, Kyle House, Barbara E John, Ryan S. Crow, Philip A Pearthree
One hundred and sixty years of Grand Canyon geological mapping
No abstract available.
Authors
Karl Karlstrom, Laura Crossey, Peter W. Huntoon, George Billingsley, Michael Timmons, Ryan S. Crow
Birth and evolution of the Virgin River fluvial system: ∼1 km of post–5 Ma uplift of the western Colorado Plateau
The uplift history of the Colorado Plateau has been debated for over a century with still no unified hypotheses for the cause, timing, and rate of uplift. 40Ar/39Ar and K/Ar dating of recurrent basaltic volcanism over the past ∼6 Ma within the Virgin River drainage system, southwest Utah, northwest Arizona, and southern Nevada, provides a way to reconstruct paleoprofiles and quantify differential
Authors
Cory Walk, Karl Karlstrom, Ryan S. Crow, Matt Heizler
Carving Grand Canyon’s inner gorge: A test of steady incision versus rapid knickzone migration
A recent study posits that much of the 240-m-deep inner gorge of Grand Canyon was carved between 500 and 400 ka via passage of a migrating knickzone with incision rates of ~1600 m/Ma during that time period; this was based on dating of a ca. 500 ka travertine deposit perched on the rim of the inner gorge, near Hermit Rapid, and a ca. 400 ka travertine drape that extends to within 60 m of river lev
Authors
Ryan S. Crow, Karl E. Karlstrom, Laura J. Crossey, Victor Polyak, Yemane Asmerom, William C. McIntosh
Science and Products
- Science
Geologic Mapping of the Lower Colorado River System
This is a comprehensive scientific investigation of the geologic history and framework of the lower Colorado River. We are using geologic mapping in combination with stratigraphic, geochronologic, and geophysical studies to develop a holistic understanding of the river’s origin, the structural history of the landscape through which it flows, and the stratigraphic and geomorphic consequences of the... - Data
Digital database for the geologic map of the Vidal, California, and Parker SW, California-Arizona quadrangles
This geologic database is a digitized version of the original 1:24,000-scale analog geologic map titled "Geologic map of the Vidal, California, and Parker SW, California-Arizona quadrangles", published by the U.S. Geological Survey (USGS) in 1980. The map area straddles the Arizona-California border, and is located approximately 9.0 km (5.6 mi) west-southwest of Parker, CA, immediately south of thDigital database for the geologic map of the Parker NW, Parker, and parts of the Whipple Mountains SW and Whipple Wash quadrangles, California and Arizona
This geologic database is a digitized version of the 1:24,000-scale original analog geologic map titled "Geologic map of the Parker NW, Parker, and parts of the Whipple Mountains SW and Whipple Wash quadrangles, California and Arizona", published by the U.S. Geological Survey (USGS) in 1980. The map area straddles the Arizona-California border and includes the community of Parker, AZ, and the soutDigital data documenting the evolution of Miocene normal and dextral faulting in the lower Colorado River region near Blythe, California, USA
These datasets provide the measurements and analytical data used to describe the evolution of Neogene faulting near Blythe, California. The data include structural measurements and results from Ar-Ar and U-Pb geochronology that address the research questions of the associated publication. Structural measurement datasets provide fault surface kinematic measurements and tabulations of structural datDigital database of geologic units, contacts, and faults for Mineral Resource Potential Map of the Turtle Mountains Wilderness Study Area, San Bernardino County, California (U.S. Geological Survey Bulletin 1713-B, 1988, Plate 1)
This map geodatabase digitally represents the general distribution of bedrock geologic map units in the Turtle Mountains area, California, as portrayed in Plate 1 of USGS Bulletin 1713-B, Mineral resources of the Turtle Mountains Wilderness Study Area, San Bernardino County, California (1988), https://doi.org/10.3133/b1713B. The map covers parts of the Rice, Turtle Mountains, and Savahia Peak 15’ - Maps
Surficial geologic map of the Spirit Mountain SE and part of the Spirit Mountain NE 7.5' quadrangles, Nevada and Arizona
This geologic map includes a trove of stratigraphic and geomorphic information that chronicles the inception and evolution of the lower Colorado River. The map area is located near the south end of the Lake Mead National Recreation Area about 80 km (50 mi) downstream from Hoover Dam. It spans parts of northwestern Arizona and southern Nevada near the south end of Cottonwood Valley. The map includeGeologic map of the Castle Rock 7.5' quadrangle, Arizona and California
The Castle Rock quadrangle is in the northeast corner of Chemehuevi Valley, California and Arizona. It includes the Colorado River’s entrance to the valley at the mouth of Topock Gorge and the northern outskirts of Lake Havasu City, Arizona, and the Chemehuevi Indian Tribe community of Havasu Lake, California. The map includes large parts of the Chemehuevi Indian Reservation and the Havasu NationaGeologic map of the Castle Rock 7.5' quadrangle, Arizona and California
The Castle Rock quadrangle is in the northeast corner of Chemehuevi Valley, California and Arizona. It includes the Colorado River’s entrance to the valley at the mouth of Topock Gorge and the northern outskirts of Lake Havasu City, Arizona, and the Chemehuevi Indian Tribe community of Havasu Lake, California. The map includes large parts of the Chemehuevi Indian Reservation and the Havasu Nationa - Publications
Filter Total Items: 16
Evolution of Miocene normal and dextral faulting in the lower Colorado River region near Blythe, California, USA
The evolution of strain in nascent continental plate boundaries commonly involves distributed deformation and transitions between different styles of deformation as the plate boundary matures. Distributed NW-striking faults, many with km-scale right-lateral separation, are prevalent near Blythe, California, and have been variably interpreted to have accommodated either Middle Miocene NE-SW extensiAuthorsSkyler Pendleton Mavor, Scott E. K. Bennett, Ryan S. Crow, John S. Singleton, Victoria Langenheim, Daniel F. Stockli, Mark E. Stelten, Timothy Brickey Sr., Paul J. Umhoefer, L. Sue BeardLate Cretaceous time-transgressive onset of Laramide arch exhumation and basin subsidence across northern Arizona−New Mexico, USA, and the role of a dehydrating Farallon flat slab
Spatiotemporal constraints for Late Cretaceous tectonism across the Colorado Plateau and southern Rocky Mountains (northern Arizona−New Mexico, USA) are interpreted in regards to Laramide orogenic mechanisms. Onset of Laramide arch development is estimated from cooling recorded in representative thermochronologic samples in a three-step process of initial forward models, secondary HeFTy inverse moAuthorsJacob Thacker, Karl Karlstrom, Shari Kelley, Ryan S. Crow, Jerry KendallFault-influenced incision in western Grand Canyon, Arizona U.S.A.
Preliminary interpretation of new and updated incision rates in western Grand Canyon shows the effects of Quaternary faulting, which dampens river incision rates in the footwalls and amplifies them in the hanging walls of normal faults. In the reach between Lava Falls and Diamond Creek in western Grand Canyon, about 178 to 225 river miles downstream from Lees Ferry, the river crosses the neotectonAuthorsRyan S. Crow, Karl Karlstrom, Warren Sharp, Victor Polyak, Yemane Asmerom, Laura CrosseyRedefining the age of the lower Colorado River, southwestern United States: Reply
Crow et al. (2021) report new geochronologic and paleomagnetic data indicating that the lower Colorado River (CR) became integrated to the proto–Gulf of California (GOC) between 4.8 and 4.62 Ma instead of at ca. 5.3 Ma, as suggested by Dorsey et al. (2007, 2018). Dorsey et al. (2021) dispute this new chronology but offer no alternative explanation for one of the key data sets requiring it, new detAuthorsRyan S. Crow, Jonathan Schwing, Karl Karlstrom, Matt Heizler, Philip Pearthree, Kyle House, Shannon Dulin, Susane Janecke, Mark E. Stelten, Laurie CrosseyRedefining the age of the lower Colorado River, southwestern United States
Sanidine dating and magnetostratigraphy constrain the timing of integration of the lower Colorado River (southwestern United States and northern Mexico) with the evolving Gulf of California. The Colorado River arrived at Cottonwood Valley (Nevada and Arizona) after 5.24 Ma (during or after the Thvera subchron). The river reached the proto–Gulf of California once between 4.80 and 4.63 Ma (during thAuthorsRyan S. Crow, J. Schwing, K. E. Karlstrom, M. Heizler, P. A. Pearthree, P. K. House, S. Dulin, S. U. Janecke, Mark E. Stelten, L. J. CrosseyPost-12 Ma deformation of the lower Colorado River corridor, southwestern USA: Implications for diffuse transtension and the Bouse Formation
Structural evidence presented here documents that deformation was ongoing within the lower Colorado River corridor (southwestern USA) during and after the latest Miocene Epoch, postdating large-magnitude extension and metamorphic core complex formation. Geometric and kinematic data collected on faults in key geologic units constrain the timing of deformation in relation to the age of the Bouse ForAuthorsJacob Thacker, Karl Karlstrom, Laura Crossey, Ryan S. Crow, Colleen Cassidy, L. Sue Beard, John Singleton, Evan Strickland, Nikki Seymour, Michael WyattThe Bouse Formation: A controversial Neogene archive of the evolving Colorado River: A scientific drilling workshop report (Feb. 28-March 3, 2019-Bluewater Resort, Parker, Arizona, USA
Neogene deposits of the lower Colorado River valley, especially the Miocene(?) and early Pliocene Bouse Formation, have been the focus of intense debate regarding the early paleoenvironmental history of this important continental-scale river system in southwestern North America and its integration with the proto-Gulf of California. Fine-grained units within these Neogene deposits also hold a promiAuthorsAndrew S. Cohen, Colleen Cassidy, Ryan S. Crow, Jordon Bright, Laura Crossey, Rebecca Dorsey, Brian F. Gootee, Kyle House, Keith A. Howard, Karl Karlstrom, Philip PearthreeInsights into post-Miocene uplift of the western margin of the Colorado Plateau from the stratigraphic record of the lower Colorado River
The spatial and temporal distribution of Pliocene to Holocene Colorado River deposits (southwestern USA and northwestern Mexico) form a primary data set that records the evolution of a continental-scale river system and helps to delineate and quantify the magnitude of regional deformation. We focus in particular on the age and distribution of ancestral Colorado River deposits from field observatioAuthorsRyan S. Crow, Keith A. Howard, L. Sue Beard, Phil Pearthree, Kyle House, Karl Karlstrom, Lisa Peters, William C. McIntosh, Colleen Cassidy, Tracey J. Felger, Debra BlockA river is born: Highlights of the geologic evolution of the Colorado River extensional corridor and its river: A field guide honoring the life and legacy of Warren Hamilton
The Colorado River extensional corridor, which stretched by a factor of 2 in the Miocene, left a series of lowland basins and intervening bedrock ranges that, at the dawn of the Pliocene, were flooded by Colorado River water newly diverted from the Colorado Plateau through Grand Canyon. This water and subsequent sediment gave birth, through a series of overflowing lakes, to an integrated ColoradoAuthorsKeith A. Howard, Kyle House, Barbara E John, Ryan S. Crow, Philip A PearthreeOne hundred and sixty years of Grand Canyon geological mapping
No abstract available.AuthorsKarl Karlstrom, Laura Crossey, Peter W. Huntoon, George Billingsley, Michael Timmons, Ryan S. CrowBirth and evolution of the Virgin River fluvial system: ∼1 km of post–5 Ma uplift of the western Colorado Plateau
The uplift history of the Colorado Plateau has been debated for over a century with still no unified hypotheses for the cause, timing, and rate of uplift. 40Ar/39Ar and K/Ar dating of recurrent basaltic volcanism over the past ∼6 Ma within the Virgin River drainage system, southwest Utah, northwest Arizona, and southern Nevada, provides a way to reconstruct paleoprofiles and quantify differentialAuthorsCory Walk, Karl Karlstrom, Ryan S. Crow, Matt HeizlerCarving Grand Canyon’s inner gorge: A test of steady incision versus rapid knickzone migration
A recent study posits that much of the 240-m-deep inner gorge of Grand Canyon was carved between 500 and 400 ka via passage of a migrating knickzone with incision rates of ~1600 m/Ma during that time period; this was based on dating of a ca. 500 ka travertine deposit perched on the rim of the inner gorge, near Hermit Rapid, and a ca. 400 ka travertine drape that extends to within 60 m of river levAuthorsRyan S. Crow, Karl E. Karlstrom, Laura J. Crossey, Victor Polyak, Yemane Asmerom, William C. McIntosh
*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