Geophysical imaging in carbonate critical zone highlights the significant of deep weathering

First the properties of weathered and unweathered rocks are analyzed on rock samples using petrological observations and petrophysical measurements. Weathered rocks appear as unconsolidated, highly porous material, resulting from dissolution at the grain boundaries of the dolomite without any significant mineralogical change from the unweathered rock. Various geophysical methods (GPR, Gravimetry, ERT, SRT) are used to identify and image the weathered areas in subsurface. The weathered rocks form numerous corridors (several meters long) both at the surface and at depth, aligned with the fractures and known caves.

By integrating multidisciplinary data from samples and field, we infer the potential presence of water in these weathered zones. This leads to a refined conceptual model of karst subsurface architecture, where weathered rocks may serve as preferential reservoirs for groundwater within the critical zone.