Derivation and application of a geologic dataset for flow modelling by discrete fracture networks in low-permeability argillaceous rocks

摘要

Argillaceous rock formation are targets of exploration for radioactive waste disposal sites in several countries. Groundwater flow in most indurated argillaceous rocks is very limited and occurs(if at all)mainly in brittle discontinuites, such as faults. On the basis of surface observations, core logging and hydraulic measurements in boreholes penetrating an argillaceous marl formation in the Swiss Alps, the relationships between internal fault architecture, large-scale arrangement of the fault network and fault transmissively are explored. Only a fraction of all faults observed in the cores correlates with water inflow points into the boreholes, and this is taken as evidence of variable transmissivity within each fault.