AN EXPERIMENTAL-STUDY OF FLOW AND TRANSPORT IN FRACTURED SLATE

A series of laboratory tracer migration experiments in a single rock f racture have been performed, and the breakthrough curves have been int erpreted using mathematical modelling. Discrepancies were observed bet ween the experimental data and the predictions made using a simple adv ection-dispersion model. The potential reasons for these discrepancies have been investigated by applying more complex models: one model inc orporates channelling of flow within the fracture, the other couples d ispersion and advection in the fracture with rock-matrix diffusion. It is concluded that channelling of flow can adequately explain the obse rved spreading behaviour; rock-matrix diffusion is not a significant m echanism influencing transport in these experiments.