Two-dimensional laboratory investigations of flow and transport in a fractu
red permeable medium are presented. Matrix blocks of a manufactured consoli
dated permeable medium were arranged together to create fractures in the sp
aces between the blocks. Experiments examined flow and transport in four di
fferent configurations: (1) matrix only, (2) and (3) matrix blocks containi
ng single fractures of different mean apertures, and (4) a brickwork patter
n setup simulating a tortuous multiple fracture network. The observed parti
tioning of flow and solute concentrations suggested mass exchange between t
he fractures and the matrix was occurring. An analysis of the experimental
results using a discrete fracture model and a range of constant aperture mo
dels showed that this approach did not capture the correct flow mechanisms.
Subsequent simulations including spatial variations of the fracture apertu
re were better able to describe the experimental observations and to show t
hat these variations cause mass exchange between the fracture and matrix.