The accretion of terranes to continental margins seems to have been an important process in the formation of the continents as we see them today. Alaska has been the site of terrane accretion at least since Mesozoic time. This proposal is concerned with the investigation of the crustal thickness and Pn velocities associated with an area that consists of accreted and possibly stacked terranes. The planned experiment uses the existing seismograph network of the University of Alaska, augmented by stations in the Yukon Flats area, to record the signals from a number of chemical explosions. The distribution of stations is such that it should be possible to look at Pn arrivals along sections across the Alaska Range, the Tanana Valley and the Yukon Flats. The latter is a large, geologically unknown area covered by recent sediments, which on some models is thought to be trapped oceanic crust.
