Talc friction in the temperature range 25°–400 °C: relevance for fault-zone weakening

Talc is one of the weakest minerals that is associated with fault zones. Triaxial friction experiments conducted on water-saturated talc gouge at room temperature yield values of the coefficient of friction, μ(shear stress, τ/effective normal stress, σ′_N) in the range 0.16–0.23, and μ increases with increasing σ′_N. Talc gouge heated to temperatures of 100°–400 °C is consistently weaker than at room temperature, andμ