Investigation of the thermal transport properties of amphibolites: I. Pressure dependence

A pulse method was used to measure simultaneously thermal conductivity and thermal diffusivity of amphibolites. Eleven samples were studied from the KTB borehole in Windisch-Eschenbach and, for comparison, five rocks fromthe Saxonian Granulite Mountains. Small differences were found in the pressure dependence of samples from different origins. The thermal transport properties were determined for pressures up to 1000 MPa. A linear dependence was observed for pressures above 50 MPa. The increase with rising pressure has been found to be relatively small compared to other rocks investigated so far: (0.75 ′0.35) x 10 - 1 GPa - 1 for thermal conductivity, (0.61′0.22) × 10 - 1 GPa - 1 for thermal diffusivity. Two rock samples showed an anomalous behaviour: their thermal conductivity increased with rising pressure whereas their thermal diffusivity decreased.