Further, he proposed that wherever un-contorted layers were exposed, the bottom layer was deposited first and was, therefore, the oldest layer exposed; each succeeding layer, up to the topmost one, was progressively younger.

We'll even visit the Grand Canyon to solve the mystery of the Great Unconformity!The method of reading the order is called stratigraphy (layers of rock are called strata).Relative dating does not provide actual numerical dates for the rocks.are deposited in a time sequence, with the oldest on the bottom and the youngest on the top." This is just as newspapers found in accumulated trash tends to be older on the bottom than they are on the top.As a member, you'll also get unlimited access to over 55,000 lessons in math, English, science, history, and more.