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146-3 Experimental Strain Rate and Confining Pressure Controls on Fault Roughness Development
Session: Fault zones and fluid flow, from outcrops to algorithms. (Posters)
Poster Booth No.: 384
Presenting Author:
Samuel Marcus
Authors:
Marcus, Samuel1, Sone, Hiroki2, Trzeciak, Maciej3, Lazarcik, James4r>
(1) Geoscience, University of Wisconsin-Madison, Madison, WI, USA, (2) Geological Engineering, University of Wisconsin-Madison, Madison, WI, USA, (3) Geological Engineering, University of Wisconsin-Madison, Madison, WI, USA, (4) Water Science and Engineering Laboratory, University of Wisconsin-Madison, Madison, WI, USA,
Abstract:
Fault and fracture roughness is a control on fault mechanical and fluid flow behavior. Roughness develops during fracture growth and during fault slip and quiescence. Controls on the development of fault roughness correspondent with deformation rate and depth are not well established. We fractured seven cores under variable confining pressures (30 - 75 MPa) and radial displacement rates (2.5*10-5 - 2.5*10-2 mm/s) using a triaxial deformation apparatus, and allowed the faults which developed to slip the same distance. We used both an optical camera and an SEM microscope to photograph the formed fracture surfaces, and developed 3D structure-from-motion models of each. We used a custom BET surface area analysis rig to measure the absolute surface area created during fracturing. Joint roughness coefficients and 1D roughness parameters (rms roughness, skewness, kurtosis) showed increasing roughness with confining pressure and displacement rate.