In this section I discuss the nature and origin of the first crust of planet Earth. This crust formed in the first 500 Ma of the history of the planet, a period from which almost no geological record remains: all we have are zircons, the majority from two localities in Western Australia, complemented by isolated grains from other regions. Our knowledge of the first crust, and the basis for our speculations as to its size, distribution and origin, come entirely from geochemical analyses of minute crystals – or even portions of these crystals – a type of research that became...

First Page Preview

First page PDF preview
You do not currently have access to this article.