This is a more than a dictionary of simple definitions, but not a definitive exposition. Geology is a subject rich in words, and here are a large number of those most commonly used. Headwords are variously accompanied by an explanation, an origin, a diagram or picture as illustration and a number of interactive links to other associated headwords. The links provide a quick and easy way for readers to cross-reference – simply by clicking onto a link. Along with astronomy, geology is perhaps the most fundamental to our understanding of the history and development of our planet and our place in the universe. This eBook is intended as a quick and easy reference tool for anyone with anything from a deep to a slight interest in one of sciences most fascinating subjects.