the Principle of Original Horizontality

The Principle of Original Horizontality is a key concept in geology that suggests sedimentary layers of rock are originally deposited in horizontal or nearly horizontal layers. This means that when you see layers of sedimentary rock, they were initially spread out flat. If they are found tilted or folded, this indicates that geological processes, such as tectonic activity, have occurred after their formation. Understanding this principle helps geologists interpret the Earth's history and the processes that have shaped its surface over millions of years.