Graduates in geology, geochemistry and geophysics will find this volume in the

Geoscience Texts series a valuable reference text. The book begins by describing the known composition of the present upper crust, then deals with possible compositions for the total crusts and the inferred composition of the lower crust. The question of the uniformity of crustal composition throughout geological time is discussed. The rate of growth of the crust through time is assessed, and the effects of the extraction of the crust on mantle compositions are considered. Finally, the question of early pre-geological crusts on the Earth is debated, and comparisons are given with crusts on the Moon, Mercury, Mars, Venus and the Galilean Satellites.