Judging by the title of this book, you might expect it to talk of 25 remarkable kinds of rocks and minerals. But in the preface, geologist and palaeontologist Donald R. Prothero makes clear that his book looks as much at famous outcrops and geological phenomena. Bringing together 25 readable and short chapters, he gives a wide-ranging tour through the history of geology, celebrating the many researchers who contributed to this discipline.
Like so many teenagers, I wanted to become a palaeontologist. However, there was no degree programme in palaeontology in the Netherlands back then (I doubt there is one nowadays), so I was advised that one option to prepare myself was to do a Master’s in biology or geology. I choose the former and never looked back, but remained fascinated with the latter. Now, twenty years later, my job exposes me to many geology textbooks and especially Cambridge University Press has a wonderful output of advanced-level books that I really want to read. But when I reviewed Earth History and Palaeogeography some time ago, I realised I was out of my depth and struggled with the jargon. Is it ever too late to start over and make an entry into a new field? I decided to shell out and invest in a textbook to find out.
What has plate tectonics ever done for us? Not having studied geology, I have a basic understanding of the movement of earth’s continents, but this book made me appreciate just how much of current geology it underpins. Marine geophysicist Roy Livermore, who retired from the British Antarctic Survey in 2006 after a 20-year career, convincingly shows here that the discovery and acceptance of plate tectonics was a turning point in geology, on par with Darwin’s formulation of evolution by natural selection. To paraphrase evolutionary biologist Theodosius Dobzhansky: nothing in geology makes sense except in the light of plate tectonics.
Before plate tectonics became an accepted idea in geology, Lyell’s doctrine of uniformitarianism still ruled supreme (see my review of Cataclysms: A New Geology for the Twenty-First Century for a short introduction). A corollary was that the continents supposedly had always been where they are now. One observation scholars had to explain away was that the same fossils occur on both sides of the various oceans. Looking at maps, some people noticed the thin strip of land connecting North and South America and concluded that land bridges must have formed and sunk beneath the waves at just the right times in history to enable migrations (see Four Revolutions in the Earth Sciences: From Heresy to Truth for more details). As explained in The Tectonic Plates are Moving!, we know better nowadays. Nevertheless, the concept of land bridges is still alive and well today, and palaeobotanist Alan Graham here introduces five of them, exploring their effects on biogeography, climate, and human history.
This book is an example of what happens when you go down rabbit holes. I have been reading several books on the subject of palaeontology and geology lately, and I know that the face of the earth has shifted over the hundreds of millions of years of deep history covered in these books. But where were all the continents at different times? Many will have seen the iconic maps of the supercontinent Pangaea. But I want to know more. What happened in between? And before? As Nield tells in Supercontinent: 10 Billion Years in the Life of Our Planet, Pangaea was only one of several such supercontinents in Earth’s history. But I want to know more still. Where exactly were the continents located? And how did they move? Several accessible books have provided snapshots of iconic moments, such as the formation of the Himalayas (Mike Searle’s Colliding Continents: A Geological Exploration of the Himalaya, Karakoram, & Tibet) or the disappearance of the Tethys ocean (Dorrik Stow’s Vanished Ocean: How Tethys Reshaped the World). But I want to know more! This technical reference work contains lots of fantastic palaeogeographical maps that answered all my questions.
Try as we might, science is very much the work of human beings with all their foibles. As such, scientific advances aren’t always straightforward and can run into opposition within scientific circles when new ideas run counter to currently established ones. In Four Revolutions in the Earth Sciences, American geologist James Lawrence Powell demonstrates this by taking the reader through the history of four ideas in the earth sciences that initially weren’t accepted. This was a book I very much wanted to read.