| Secondary Fault Structures as Indicators of Rupture Velocity | |
| Personnel: A. Griffith, D. Pollard Sponsor: Stanford Rock Fracture Project | |
| Description:
The purpose of this project is to document a number of fault related structures predicted by considering the transient stress
field around a propagating rupture and ultimately to introduce a catalogue of structural features resulting from, and indicative
of, high rupture velocities. We are working to classify and explain a number of secondary fractures related to
pseudotachylyte-bearing faults of the Fort Foster Brittle Zone in southeastern Maine and faults of the Mt Abbott quadrangle in
the Sierra Nevada Mountains.
This work has been motivated by deviations of secondary features from the orientations predicted by quasi-static linear elastic fracture mechanics. In the past, structural geologists have utilized a Lagrangian approach to characterize the fracture kinematics and mechanics of exhumed faults based on post-deformational geometry and structure of the main fault and related secondary features. To this point in time, the vast majority of field-based work has considered only the contribution of the quasi-static stress field to deformation on and near the main fault, ignoring dynamic effects.  | |