A barrier on a fault was constructed in a concrete model. Two sets of lubricated glass plates were cast into the specimen to represent the previous broken, low friction part of a fault. An intact concreate barrier in line with and between the sets of glass plates was caused to fail under axial loading. The fault plane crossed the sample, a rectangular parallelopiped, at an angle of 35¿ with respect to the long (also the loading) axis. As the sample was loaded, axial and transverse strains in the vicinity of the barrier were monitored with conventional strain gages. Differntial surface uplift was measured by double-exposure holography. Acoustic emissions were recorded digitally from the signals of piezoelectric compressional wave transducers. The axial loading was controlled such that the shortening rate of the sample was constant. Initial elastic deformation was followed by nonuniform strain concentrated in the barrier region. Acoustic emissions in the early stages of loading occurred diffusely and were predominantly tensional character, i.e., compressional arrivals on all transducers. Intensive deformation was concentrated near the barrier ends. After the maximum applied force had been reached, maxima in axial deformation were observed, first far from the barrier and slowly migrating toward the eventual rupture. Small force drops, i.e., small local failures, were associated with axial extension far from the fault and axial shortening near the fault. Shear-type acoustic emissions were observed to dominate in the later phases of deformation leading to the catastrophic failure of the barrier. ¿ American Geophysical Union 1987