The articles in this volume were selected from a series of reports delivered in the So viet Union at Yaroslavl during the International Seminar "Super-deep drilling and deep geophysical research," which was organized and held in August 1988 by the Ministry of Geology of the USSR, jointly with the Inter-Union Commission on the Lithosphere. One of the most important problems of modem geology, is the state and prospects of further development of deep continental structure investigations, was discussed at the seminar with the participation of 245 scientists and specialists from 19 countries. At the plenary and sectional meetings of the seminar, 83 reports were delivered, discussions on the most interesting problems were organized, the exchange of ideas between the leading scientists a round table took place in discussion. The distinctive feature of the present collection of articles is the wide scope of the investigation of the Earth's crust. The reports elucidate such subjects of world impor tance as (1) achievements in implementation of major scientific programs investi gating deep Earth structure and plans for their further materialization; (2) theoretical problems of carrying out geological-geophysical explorations and drilling operations; and (3) new approaches to the study of the Earth's interior. The results of deep inves tigations of individual countries and organizations are considered, and concrete tech nical elaboration, methods of work execution, etc. are discussed."

The present book is devoted to the study of the deep Earth's interior structure, one of the most important problems of Earth sciences today. The drilling of the Kola superdeep well inaugurated a new stage in the study of the Precambrian continental crust. The well was sunk in the northeastern part of the Baltic Shield, in an area where the Precambrian ore-bearing structures, typical of the ancient platform basements, are in juxtaposition with each other. To the present the well has been drilled to a depth of 12 km, has traversed the full thickness of the Proterozoic complex and a considerable part of the Archean stratum, and is still be ing worked on. This book reviews the principal results of investigations to a depth of 11,600 m; these are described in three sections: geology, geophysics, and drilling. The book begins with a general review of the history, the present state of knowledge, and trends of further investigations in the field of study of the Earth's interior and superdeep drilling. The first section of the book considers the geology of the vicinity of the Kola superdeep well and describes its geological section based on a detailed examination both of the cores and the near-borehole area."