Race after race resigned their fleeting breath
The rocks alone their curious annals save.
- T. A. Conrad
Look ye unto the rock whence you are hewn
and to the hole of the pit whence ye are digged.
- Isaiah 51:1
Geologic Time
Principle of Original HorizontalityGeologic Time Scale
Principle of Superposition
Principle of Cross-cutting relationships
Principle of Original Lateral Continuity
Principle of Faunal Succession
Cenozoic - Age of Mammals - 65 Myr to present
Mesozoic - Age of Dinosaurs - 250 to 65 Myr
Paleozoic - Age of Ancient Life - 570 to 250 Myr
Precambrian - Age of all-soft-bodied life - 4.55 to 0.57 Byr