Title of the talk: Understanding earthquakes from the study of pseudotachylytes: examples from the micrometric to the lithospheric scale
A pseudotachylyte is a quenched melt produced by frictional heating during an earthquake. As such, pseudotachylytes are an evidence of seismic failure in silicate rocks. The study of pseudotachylytes and their host-rock microstructures is a valid approach to investigate earthquake processes at depth and can provide information on the mechanics of seismic failure and more in general on the rheology of the lithosphere.
Two case studies based on pseudotachylytes are presented:
- the full estimate of the energy dissipated on the fault plane during an earthquake at mid-crustal conditions, investigated with microstructural observations and HR-EBSD analysis on a pseudotachylyte fault vein from the hanging wall of the Woodroffe Thrust (Musgrave ranges, central Australia)
- the intermediate-depth subduction seismicity, whose predisposing conditions are numerically modelled on a lithospheric scale extrapolating the occurrence of deep subduction-related pseudotachylytes in dry peridotites to a general model of stress amplification promoting seismic failure.
To get news, invitations to seminars and more from Njord, please go here to subscribe to our newsletter.