The history of rocks

Yesterday I received a book in the mail, Unearthing the History of Rocks, by Ken McNamara. It was recommended to me fellow blipmate sheilwill.  I've reached page 29 without the aid of a parachute, which means that I will undoubtably read all of this fascinating book. Already I can tell the difference between sedimentary rocks and sedititionary ones. It's all a new world to me.