Fig. 6
High-resolution micromilled stable carbon and oxygen isotope profiles analyzed across typical growth intervals (from base to growth surface, yellow rectangles) of carbonate scale-fragments deposited inside borehole pipes of the two geothermal facilities (KIR and DUR). The distinct spatiotemporal variations mostly reflect variable CO2 and H2O outgassing (affecting δ13C and δ18O) probably associated with variable (micro)turbulences at the rough calcite scale versus thermal fluid interface, as well as some contribution from temperature changes (mainly affecting δ18O) associated with the thermal water production conditions. See text for details