Seismic Reflection Studies of Deep Crustal Structure

knowledge of the third dimension is vital. The means of exploring the depth dimensionange from inference based on surface geology to sampling of deeper rocks by drill or studying igneous activity, through application of a variety of geophysical techniques. This review describes the rather recent application of the powerful seismic reflection profiling technique, which was developed by the petroleum industry in the search for hydrocarbons in sedimentary basins, to the study of the basement rocks of the continents. This method of study of the contin ental crust is in its infancy ; onl y a few si tes represen ting a tiny fraction of the con tinen tal basement have so far been explored. The results, however, are proving informative and critical for enhanced understanding of some of the fundamental questions