martes, 8 de mayo de 2012
Lyme Regis Fossil Festival
Discovering Earth – Fossil Festival 2012
Fossils have played a pivotal role in the birth of the earth sciences. They’ve helped scientists to understand that our earth is billions of years old, that life forms evolved and continue to do so, that much of the earth and stone we walk upon was created when sediment was deposited on the bottom of ancient sea-beds, and that this sea-bed – indeed the whole of the earth’s crust – is moving all the time.
Humans have always been puzzled by and sought to explain fossil remains. While some clearly resembled known plants and animals, others did not, and the question of how they could come to lie on the ground in some places and be buried so deep in others was a mystery.
Why do some types of fossil exist only in one layer, or one type of rock? Ammonites in general are in many different layers, but they evolved rapidly, and so are ‘zonal fossils’. The particular type of ammonite can tell you a great deal about the age of the layer of rock that it’s found in, anywhere in the world. When scientists realised that the same types of fossils were found on the coasts of continents thousands of miles apart is was one more piece of evidence that helped to prove continental drift, and the fact that our earth was once one great supercontinent (Pangea) that broke apart.
If you still want to know more about fossils...