T32B:
Flow and Fracture: Mixed Brittle-Viscous Behavior Throughout the Lithosphere I


Submit an Abstract to this Session


Session ID#: 57183

Session Description:
Observations of naturally deformed rocks demonstrate that discrete brittle structures are found in regions of the earth associated with ductile deformation – including hot crust, melt or fluid-migration structures, and slowly deforming areas.  Similarly, examples of continuous deformation within the ‘brittle’ crust abound – from soft sediment deformation, to cataclastic flow in fault zones, to post-seismic plastic deformation.  Advances in laboratory experiments and numerical techniques have accelerated our phenomenological and quantitative understanding of geologic environments where brittle-ductile behavior might be rate-dependent, scale-dependent, fluid pressure-dependent, reaction-dependent, or time-dependent. Classic lithospheric strength profiles are based on locating intersections between frictional and viscous flow laws, but don’t account for solution creep or for spatially variable strain rates that we know characterize deforming regions of the earth.  This session invites observations of mixed brittle-viscous behavior, conceptual or mechanical models of spatially and temporally heterogeneous deformation mechanisms, and bulk rheological consequences of mixed behavior.
Primary Convener:  Christie D Rowe, McGill University, Dept of Earth and Planetary Sciences, Montreal, QC, Canada
Conveners:  Whitney M Behr, Structural Geology & Tectonics Group, Dept. of Earth & Planetary Sciences, ETH Zürich, Zürich, Switzerland, Christopher C Gerbi, University of Maine, School of Earth and Climate Sciences, Orono, ME, United States and Andre R Niemeijer, Utrecht University - Faculty of Geosciences - HPT Laboratory, Department of Earth Sciences - HPT Laboratory, Utrecht, Netherlands
Primary Liaison:  Christie D Rowe, Nevada Seismological Laboratory, Reno, United States
Chairs:  Christie D Rowe, Nevada Seismological Laboratory, Reno, United States, Christopher C Gerbi, University of Maine, School of Earth and Climate Sciences, Orono, ME, United States, Andre R Niemeijer, Utrecht University - Faculty of Geosciences - HPT Laboratory, Department of Earth Sciences - HPT Laboratory, Utrecht, Netherlands and Whitney M Behr, Structural Geology & Tectonics Group, Dept. of Earth & Planetary Sciences, ETH Zürich, Zürich, Switzerland
OSPA Liaison:  Christopher C Gerbi, University of Maine, School of Earth and Climate Sciences, Orono, ME, United States
Co-Organized with:
Tectonophysics, and Mineral and Rock Physics

Cross-Listed:
  • MR - Mineral and Rock Physics
  • NH - Natural Hazards
  • S - Seismology
  • V - Volcanology, Geochemistry and Petrology

Proposed Co-Organized Session with:
  • MR - Mineral and Rock Physics
Index Terms:

3902 Creep and deformation [MINERAL PHYSICS]
8004 Dynamics and mechanics of faulting [STRUCTURAL GEOLOGY]
8159 Rheology: crust and lithosphere [TECTONOPHYSICS]
8434 Magma migration and fragmentation [VOLCANOLOGY]

Abstracts Submitted to this Session:

Low-angle brittle thrusting, localized viscous shear, and metasomatic reactions recorded in subduction mélanges: Implications for slow earthquakes in subduction zones (366139)
Kohtaro Ujiie1,2, Hanae Saishu3, Kazuya Noro1, Ake Fagereng4 and Christopher Tulley5, (1)University of Tsukuba, Tsukuba, Japan, (2)JAMSTEC, Yokohama, Japan, (3)AIST, Tsukuba, Japan, (4)Cardiff University, Cardiff, CF24, United Kingdom, (5)Cardiff University, Cardiff, United Kingdom
Stress History During Exhumation from HP-LT Metamorphic Conditions – Transient Deformation at Low and High Stress-Loading Rates in a Ductile Extensional Shear Zone, Central Crete (392147)
Lina Seybold, Ludwig Maximilians University of Munich, Munich, Germany and Claudia Trepmann, Ludwig Maximilian University of Munich, Munich, Germany
Quartz α↔β Phase Transition Drives Brittle Damage and Reaction in Viscous Continental Crust (369822)
Scott E Johnson1, Won Joon Song1, Alden C Cook2, Senthil S Vel2 and Christopher C Gerbi1, (1)University of Maine, School of Earth and Climate Sciences, Orono, ME, United States, (2)University of Maine, Department of Mechanical Engineering, Orono, ME, United States
Comparison of brittle- and viscous creep in quartzites: Implications for semi-brittle flow of rocks (Invited) (377305)
Jacqueline E Reber, Iowa State University, Geological and Atmospheric Sciences, Ames, United States
Shear Heating and the Brittle-Ductile Transition: Thermomechanical Earthquake Cycle Simulations on Continental Strike-Slip Faults (412040)
Kali L Allison, Stanford University, Stanford, CA, United States and Eric M Dunham, Stanford University, Department of Geophysics, Stanford, CA, United States
Fluid infiltration promotes both ductile and brittle deformation within the deep crust: Examples from Southwestern Montana and the Central Alps (Invited) (424100)
Cailey Brown Condit1, Melodie E French2, Kevin H Mahan3, Cin-Ty Lee4, Justin Hayles5 and Laurence Yeung5, (1)Massachusetts Institute of Technology, Cambridge, MA, United States, (2)Rice University, Earth, Environmental and Planetary Sciences, Houston, TX, United States, (3)University of Colorado at Boulder, Geological Sciences, Boulder, United States, (4)Rice University, Department of Earth, Environmental and Planetary Sciences, Houston, TX, United States, (5)Rice University, Houston, United States
A Stress Perturbation Model in the Context of the Earthquake Cycle for Mid-crustal Earthquake Rupture in the Homestake Shear Zone, Colorado (425187)
Joseph L Allen, Concord University, Physical and Environmental Sciences, Athens, WV, United States and Dr. Colin A Shaw, Ph.D., Montana State University, Department of Earth Sciences, Bozeman, MT, United States
Solid flow regimes within sliding interfaces: some insights from numerical tribology (408469)
Guilhem Mollon, INSA Institut National des Sciences Appliquées, Toulouse Cedex 04, France

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