Slip distribution at depth on a fault may be inferred from the deformation observed on the surface. In inverting the surface deformation data to obtain the slip distribution, the Earth is generally approximated by an elastic half-space. Slip distributions inferred from a half-space model may contain artifacts, including zones of reversed slip, due solely to effects of layering in the real Earth. This effect is demonstrated for a vertical strike-slip fault in an Earth consisting of an elastic layer overlying an elastic half-space. Slip on the fault is taken to be independent of the along-strike coordinate (i.e., antiplane strain is assumed). For a given slip distribution in this model the slip distribution on a similar fault in an elastic half-space is found that produces the identical surface deformation. Comparison of the two slip distributions reveals structure introduced into the half-space equivalent slip profile by crustal layering. The comparisons suggest that low-resolution inversion schemes (e.g., single screw dislocation models) are not drastically affected by Earth structure, but attempts at detailed inversion are likely to produce profiles contaminated by artifacts of Earth structure. ¿American Geophysical Union 1987