ACTIVE TECTONICS/GEOMORPHOLOGY PROJECTS
Pleistocene to Recent Incision Rates along the northern Rio Grande River Gorge in northern New Mexico
Terraces developed along the Rio Grande del Norte in northern New Mexico provide unique insight into the geomorphic evolution of this youthful river gorge. We are using detailed geomorphic mapping along with cosmogenic 3He dating to quantify incision rates and relate them to climatic and tectonic forcings.
Collaborators: Travis Clow*, Peter Gold*, Mark Helper, Des Patterson
Long term slip rate of the Banning and Mission Creek strands of the southern San Andreas fault
Offset geomorphic features along the San Andreas fault in southern California record the fault’s rate of motion averaged over the past 50,000-150,000 years.
Funding: Southern California Earthquake Center (SCEC), National Earthquake Hazards Reduction Program (NEHRP)
Collaborators: Peter Gold*, Juan (JJ) Muñoz*, Warren Sharp, Dylan Rood, Tom Rockwell, Katherine Kendrick
Publications: Gold, Behr, et al., JGR (2015)
Kinematics and rates of slip along the Agua Blanca and San Miguel-Vallecitos fault zones in Baja California, Mexico
The Agua Blanca and San Miguel-Vallectios faults in Baja California together accommodate ~14% of plate boundary motion at this latitude. We are investigating their rates of slip and kinematic linkages with other faults within the San Andreas system and faults within the Gulf of California Rift Zone.
Funding: Southern California Earthquake Center (SCEC)
Collaborators: Peter Gold*,John Fletcher, Alejandro Hinojosa Corona, Tom Rockwell,
STRUCTURAL GEOLOGY/RHEOLOGY PROJECTS
Present-day rheology of the lithospheric mantle beneath the Mojave region from naturally deformed peridotite xenoliths.
Funding: NSF Tectonics Program
Collaborators: Rachel Bernard*, Greg Hirth, Rick Hervig, Andy Freed
Publications: Behr & Hirth, EPSL (2014)
Deformation in the mantle wedge associated with Laramide flat-slab subduction.
Inclusions in serpentinized ultramafic diatremes erupted within the Colorado Plateau represent pieces of the variably hydrated mantle wedge, as well as tectonically eroded and entrained fragments of the plate interface, each associated with Laramide flat-slab subduction. They provide a unique opportunity to investigate the effects of water on olivine lattice preferred orientations, with implications for seismic anisotropy in the mantle wedge.
Collaborators: Doug Smith
Mechanisms and longevity of strain localization during dynamic recrystallization of olivine.
Experiments being undertaken on dry olivine aggregates help determine why Earth’s rigid outer shell, the lithosphere, is commonly localized into faults and shear zones, rather than distributed over wide distances.
Funding: NSF Tectonics Program
Collaborators: *Pamela Speciale, Greg Hirth
Rheological Evolution of Subduction Interface Shear Zones: Insights from Exhumed Subduction Complexes
High pressure subduction complexes preserve on Syros Island in Greece record different mechanical behaviors as they transition from subduction to exhumation.
Funding: NSF CAREER Grant
Collaborators: Alissa Kotowski*, Danny Stockli, Jaime Barnes, Miguel Cisneros*, Spencer Seman*, Natalie Raia*
* = UT student working on project