An evaporitic dissolution breccia occurs in the Lower Visean limestones of southeastern Belgium. Three periods of brecciation have been recognized, the first of which took place early in the diagenetic history. The breccia matrix consists of infiltrated marine sediments. The fragments and the sedimentary matrix subsequently neomorphosed and lithified in meteoric waters. Multiple water-rock interactions in an open system caused an oxygen isotopic composition of the limestones in equilibrium with meteoric water. This composition varies between -8.9 and -5.5 parts per thousand depending on the palaeogeographical position. The early diagenetic interaction led also to a spread in the carbon isotopic composition, which ranges between an Early Visean marine (deltaC-13 = +4 parts per thousand(PDB)) and a palaeosol (deltaC-13 = -3 parts per thousand(PDB)) isotopic composition.