Fig. 4

a Example of a sample prepared for thermal conductivity measurements (sample J-CE; Calcaire d’Ettendorf). The samples were cut and polished to produce at least two planar and parallel surfaces. b Double-sided thermal conductivity measurement on J-CE sample in the dry state at ambient temperature. The two pieces of sample are placed either side of the sensor. The pieces are clamped together, to ensure a good contact between the pieces of sample and the sensor, using a metal screw at the top of the jig. c Schematic showing the setup and the volume around the sensor (probing depth) investigated during the measurement