We have demonstrated that a seismic solution of a set of ocean crustal P and S wave data from the Guadalupe Island area is consistent with measured P and S velocity samples from the Bay of Islands Ophiolite Suite and the observed stratigraphy. The seismic model (SOD-1), derived separately for the P and S wave propagation, contains no major interfaces in velocity between the sea floor and the upper mantle. Although the observations do not prove the Bay of Islands Ophiolite Suite is obducted oceanic crust they do lend considerable support to this hypothesis. These observations also demonstrate that a layered sequence of rock types is not incompatible with velocity models in which the velocity changes smoothly rather than abruptly with depth. A new method for determining lithology as a function of depth, which is based on Vp and Vs, is presented.