Pre‐Mesozoic Ice Ages: Their Bearing on Understanding the Climate System

Abstract

It is a pleasure to read a book that summarizes a well‐respected scientist's lifetime experience with a subject. In this particular case the subject involves pre‐Mesozoic glaciations, and the author, John Crowell, has played a key role over the last few decades in both fundamental research and synthesizing our understanding of this interesting and important topic.Crowell's book, which is a monograph in the true sense of the word, summarizes in considerable detail the various types of geologic evidence for glaciations in the Late Paleozoic (256–338 Ma), Late Devonian‐Early Carboniferous (353–363 Ma), Late Ordovician‐Early Silurian (429–445 Ma), Early Cambrian/Neoproterozoic (∼520–950 Ma), Early Proterozoic (2200–2400 Ma), and the earliest glaciation recognized so far, in the Archean of South Africa (∼2950 Ma). There is also a brief but valuable discussion of the nature of evidence for cooling in the Cretaceous.