The Second International Symposium on Observation of the Continental Crust Through Drilling (supported by the Alfred Wegener Foundation, the Federal Ministry of Research and Technology, the German Research Society and the Inter-Union Commission on the Lithosphere) took place in Seeheim (Odenwald) and included a discussion on the Continental Deep Drilling Programme of the Federal Republic of Germany. This sym- posium was regarded as the continuation of a course agreed upon in Tarrytown in 1984. Here, the scientific contents and technical con- cepts of the technically complex and expensive experiments of conti- nental drillings were carefully coordinated before the national commit- tees carne to practical decisions. In Seeheim, rather than in Tarrytown, the methods of technical realization were in the foreground, as the results of scientific projects, e. g. , the NAGRA or the Salton Sea Scien* tific Drilling Project, were evaluated, supplementing industrial ultra- deep drilling experience. The presentation and discussion of the Con- tinental Deep Drilling Project of the Federal Republic of Germany was also granted ample scope with nine lectures and sixty posters. The con- tents of the KTB presentation have been summed up in two contributions and included in this volume. The conference centered on three major subjects: The National- Prograrrunes and Aspects of Geoscience: H. Vidal, FRG; H. Riesen- huber, FRG; E. Seibold, FRG; K. Fuchs, FRG; Cl. Megnien, F; R. S. An- drews, USA; F. G. Stehli, USA; E. A. Kozlovsky, USSR; E. V.