Hydrothermal friction experiments in quartzite: The effect of temperature and normal stress on strength recovery

Laboratory slide-hold-slide tests were conducted in a conventional triaxial deformation configuration on 3/4-inch diameter cylindrical cores of Eureka quartzite bisected by a sawcut oriented at 30 degrees from vertical. Tests were conducted at constant normal stresses of 30, 110, and 210 MPa with a 10 MPa pore fluid pressure. The pore fluid was deionized water. Experiments were conducted at temperatures of 22, 100, and 200 degC.