the.com/rock layers
earth's diary, written in mud, filed in the order it happened.
means stacked bands of sediment or volcanic material, each one a snapshot of the conditions when it settled.
from from stratum, latin for something spread out — 17th century geologists noticed cliffs looked like shelved books and named the shelving stratigraphy.
law of superpositionolder layers sit below younger ones, barring chaos
grand canyon spanexposes nearly two billion years of layers
tilted layersmean the ground itself got shoved sideways