The Crafoord Prize 1986

The Royal Swedish Academy of Sciences has awarded the Crafoord Prize 1986 of 1 340 000 SEK to professor Claude J. Allègre, Universitè de Paris, France and professor Gerald J. Wasserburg, California Institute of Technology, Pasadena, USA, for their pioneering work in isotope geology.

Allègre´s and Wasserburg´s imaginative research has led to a better understanding of the formation and evolution of the solar system, Earth, Moon and the meteorites, the genesis of Earth´s atmosphere and the relationship between the superficial crust and the subjacent mantle of the planet. It has also resulted in the development of new research instruments, techniques and approaches.

The Crafoord Prize is one of the largest prize awards in science. It is awarded yearly in one of the fields of mathematics, biosciences, astronomy and as this year in geosciences.

Claude Allàgre and Gerald Wasserburg will receive their award from the hands of His Majesty the King during a ceremony at the Royal Swedish Academy of Sciences in Stockholm, Sweden on September 24th, 1986. On the same day they will give a public lecture. To support Swedish research in isotope geology Crafoord grants of 715 000 SEK from the Anna-Greta and Holger Crafoord´s fund will also be awarded.

Isotope geology is a branch of Earth and planetary science crucial in modern geological research. It allows the dating of geological processes and the tracing of the development of Earth and the planetary system back to the time when they consolidated from the solar nebulosa.

Claude Allègre´s work has mainly emphasized terrestrial geochemical problems amenable to isotope and trace element studies. His exceptionally imaginative contributions have paved the way for a better understanding of the Earth´s crust and mangle, and the complex interaction between these two major components of our planet. Allègre´s work has also produced sophisticated models of a large number of geological processes including volcanism, the evolution of the Earth´s atmosphere and the formation of the planet proper.

Allègre and Wesserburg have both done much to introduce and develop a range of parent-daughter isotope approaches, among them the revolutionary Sm-Nd method (the elements Samarium and Neodymium) of dating and the study of Nd isotope systematics. These approaches opened new horizons in the investigation of the interior of the planet and the controls it exercises on geological processes close to the Earth´s surface.

Gerald Wasserburg has had a major impact on our knowledge of the universe we inhabit, focusing on the origins and history of the solar system and its component bodies. His work established a time scale for the development of the early solar system including the end of the process of nucleosyntheses and the formation of solid objects such as the planets, the moons, and the meteorites about 4500 million years ago. A specific, exciting detail is the demonstration of the one-time presence of the relatively short-lived radioactive aluminum isotope 26 al in the solar system. Its introduction was probably due the explosion of a supernova star close to the solar nebulosa shortly before our array of planets started forming.

Widely acknowledged are Wasserburg´s studies of lunar materials collected by the Apollo missions and his wise council given to the development of the US space research programme. The isotope studies of extraterrestrial materials necessitated his pioneering work in the development of precise laboratory techniques and imaginative analytical approaches.

There are only some of the facets of immense creative contributions which have a lasting impact on the geological sciences.