|Underground Lesse (Han-sur-Lesse)|
Different points of view on karstogenesis; Fundamental and applied aspects
From 7 to 11 October 2012
In the paleokarsts from Hainaut (Belgium), you can find weathering features similar to soil features: an "in situ" limestone weathering with residual weathered-rock ("ghost-rock") that keeps its initial volume. Geological features like chert beds, stratification, and joints filled with calcite veins, remain although they present higher porosity. The weathering follows the joints and moves laterally by weathering fronts which can isolate intact blocks. We have given the name of "ghost-rock" to those features. The morphological expressions of ghost-rocks consist in corridors situated on vertical joints which have conducted aggressive water in a quiet phreatic zone and pseudoendokarstic features totally inserted in the unweathered bedrock.