Written By: Ehsan Jahandarpour

The law of superposition (or the principle of superposition) is a key axiom based on observations of natural history that is a foundational principle of sedimentary stratigraphy and so of other geology dependent natural sciences: Sedimentary layers are deposited in a time sequence, with the oldest on the bottom and the youngest on the top. The law was formulated in the 17th century by the Danish scientist Nicolas Steno.