Just Finished Reading: The Planet in a Pebble – A Journey into Earth’s Deep History by Jan Zalasiewicz

I never thought I’d say that I’ve read an interesting (indeed often fascinating) book on Geology, but here it is. The author starts with a deceptively simple question as he picks a stone off the beach: Where did this stone come from? The simple answer would be to say that it was part of a much larger rock that fell off the cliff face onto the seashore where it rolled around in the surf for long enough to lose its rough edges and become pebble shaped. But take it back a bit further: Where did the cliff come from?

It’s then that the author takes a huge, and I do mean huge, step back in time to the origin of everything in the Big Bang – or actually some minutes after the Bang when atoms started forming. I knew at that point I was going to be in for quite a ride! Moving along quickly from the first stars (which produced most of the atoms we know and love) to the heavier atoms produced in Supernova and onto later generation stars – like our Sun – and to the formation of the Earth itself the author follows the tale of the elements that are contained within the handful of rock. He follows then through the cooling of the crust, asteroid and comet impacts (which added countless atoms not originally in this part of the accretion disk) and the eventual creation of oceans and landmasses. Then we get erosion and deposition, Continental Drift and zones where massive plates are forced deep underground to melt in the fires of the core. Close analysis of the rock gives rise to discussion of how life played its part in its creation and shaping, how sea creatures both above and on the sea floor made their individual contributions over the eons with their bodies. Anyway, you get the picture of the grandeur and the level of details we’re dealing with here – basically everything from the creation of whole planets to the impact of microscopic plankton dying in their millions. It’s certainly one hell of a narrative the author weaves just to explain the rock he’s holding in his hand. It puts things in the kind of perspective you feel when you realise for the first time that the stars twinkling in the night sky are actually suns with (probable) planets around them and the fact that the Earth has been around for around 4 billion years. It’s the wow factor.

Geology has never been my strong point. I have an appreciation of the basics of rocks and stuff but hadn’t really, until reading this book, put it all together in a way for it to make a fully coherent story. I now feel that, along with a much greater appreciation of rocks, I have at least an appreciation of where things fit together. I certainly learnt a lot reading this book and, unless you are already a jobbing geologist, I’m sure you will too.