The third part of the debate about time classification and correlation of Precambrian rocks and events in Canada continues with discussion of the fundamental philosophies of geological time scales, assessment of previous proposals and the description of a chart with three scales. This chart, intended for use in the Geological Atlas of Canada, includes a chronometric scale for international correlation and reference to isotopic ages, the chronometric/chronolithic hybrid scale proposed for the Decade of North American Geology publications, and a modified (primarily chronolithic) version of Stockwell's chrono-orogenic scale which appeared in the first part of this debate.

Wilks provides a historical background, list of publications, and description of activities for most of the major science initiatives undertaken at the federal level. He surveys a wide range of government documents and monographic and serial science collections used by both faculty and students.

In the second edition Steve Kesler (University of Michigan) has been added as an author to rewrite some chapters. The motivation for this revised edition is to more intensively address economic issues that surround the exploitation of mineral resources. This emphasis gives the book a unique character. With these sections Metals and Society deals with issues that pervade much of current science reporting – the rate of exploitation of natural resources, the question of when or if these resources will be exhausted, the pollution and social disturbance that accompanies mining, the compromises and challenges that arise from the explosion of demand from China, India and other rapidly developing countries, and the moral issues that surround mining of metals in lesser developed countries for consumption in the “first-world” countries. With its dual character, the book will be useful as an introductory text for students in the earth sciences and a reference volume for students, teachers and researchers of geography, economics and the social sciences.