fossils silent witnesses to the sea that once existed here. was we here seems interested as these are remnants of the tech this ocean so this is a coral colony and it's to do these are branches of coral cement wife solution would you on here we have a cross-section which is why they look round and see you and we think they were part of a small reefs a few meters in diameter and. all the rock in this section of the else was formed by organisms the limestone was produced by both corals and miniscule algae over the course of millions of years it built up on the seabed to form a three kilometer thick layer. when the african tectonic plate began to drift towards europe one hundred million years ago the seabed broke apart and was subjected beneath africa. as the two continents collided the layers of rock were pushed upwards probably to heights of up to six thousand meters. erosion by