Fig. 3

a Profile of the vertical surface heat flow along the x-axis. The dotted line corresponds to the mean value of the heat flow. b Comparison of the simulated temperature profile obtained at the middle of the Rittershoffen mesh grid and the observed profile at GRT-1 well. The dotted lines correspond to the well-known lithological transitions. c Maps of calculated temperatures (background colors) and Darcy’s velocities (black arrows). The green dashed line is the location of the simulated profile shown in the left. The black lines are the transitions between the four idealized units