Dating and correlating rock layers
The Trias rocks in turn, were found to underlie rocks named Cretaceous in England (the chalky White Cliffs of Dover).n 1835, Adam Sedgwick (Britain) and Roderick Murchison (Scotland) decided to name the entire succession of sedimentary rocks exposed throughout Europe.
They were geology colleagues and friends, but they had a famous argument over the division between the Cambrian and Silurian in Wales.
Throughout the history of life, different organisms have appeared, flourished and become extinct.
The method of reading the order is called stratigraphy (layers of rock are called strata).NSF Postdoctoral Research Fellow at Stony Brook University.