Many of you will have heard me discuss in class that when I was a student (which isn't that long ago!) I learnt that the oldest rock in the crust was 3,800 Ma from Greenland; this had changed to 4.200 Ma from dating a rock in northern Canada. We now have to revise that number again as a Zircon crystal from Western Australia has been dated (by the Uranium-Lead method) to be 4,400 Ma. We still have meteorites that are older, but we are finding fragments of the earliest crust which may give us an indication of the processes that formed our planet.
Lagerstätten are sedimentary deposits that show remarkable fossils that otherwise would not be preserved. It is a German word that literally means "resting place" which, I think, is a very appropriate word for such a special and important piece of the fossil record.
There are quite a few of these around the world which give us tantalising snapshots from the history of life. Several of these are very important in our understanding of key moments in evolutionary history such as Archaeopteryx (shown above) from the Solnhofn Limestone in Germany and the incredible soft-bodied "experimental life forms" of the Burgess Shale.
Another of these was discovered very recently, a site of a mass beaching of whales in the late Tertiary of Chile.
