Overview
The geologic record, in stratigraphy, paleontology and other natural sciences, is the entirety of the layers of rock strata - deposits laid down by volcanism or by deposition of sediment derived from weathering detritus. This includes all its fossil content and the information it yields about the history of the Earth: its past climate, geography, geology and the evolution of life on its surface. According to the law of superposition, sedimentary and volcanic rock layers are deposited on top of each other. They harden over time to become a solidified (competent) rock column, that may be intruded by igneous rocks and disrupted by tectonic events.