A major principle of stratigraphy stating that within a sequence of layers of sedimentary rock, the oldest layer is at the base and that the layers are progressively younger with ascending order in...

Extracted text: A major principle of stratigraphy stating that within a sequence of layers of sedimentary rock, the oldest layer is at the base and that the layers are progressively younger with ascending order in the sequence. The law of relative dating The law of original horizontality The law of superposition The law of cross-cutting O The law of lateral continuity