The crustal structure of the Transantarctic Mountains (TAM) reflects significant details concerning the interaction and tectonic histories of East and West Antarctica. Yet, relatively little is known about the lithospheric structure of the TAM. Strong constraints on the lithospheric structure beneath the TAM are needed to discriminate between various models put forth to explain the evolution of TAM uplift. This investigation will use a land-based digital seismic recording array at two location in the TAM to obtain two densely recorded seismic profiles across the TAM Front near Terra Nova Bay and in the Wright Valley. The Bundesanstalt fur Geowissenschaften, Federal Republic of Germany, will provide large marine airgun seismic sources in conjunction with the GANOVEX-V Expedition during the 1988/89 field season. Seismic waveform modeling will be used in conjunction with array processing techniques to derive maximum constraints on TAM lithospheric velocity structure. Seismic results will be integrated with geopotential field data and geochemical data to determine the most appropriate models of TAM structure, composition, and tectonic evolution.