Young Earth

''What are we going to do with a parcel of old stones?'' wrote the director of an African museum a century and a half ago, when one of my ancestors presented him with a splendid collection of fossils of mammal-like reptiles. Old stones, however intriguing, are difficult to interpret, dusty, and do not fit well in the neatly ordered contents of a house of learning. Archaean geology, which is the study of the Earth''s history in the period from after 9 the end of planetary accretion (4.5-4.4 x 10 years ago) up to the beginning 9 of the Proterozoic (2.5 x 10 years ago) is much the same - a parcel of old stones seemingly impossible to understand. Yet these stones contain the history of our origins: they can tell us a story that is interesting not just to the geologist (for whom this book is primarily written) but instead addresses the human condition in general.