The Law of Original Horizontality

The Law of Original Horizontality states that sedimentary rock layers are originally deposited in nearly flat, horizontal positions due to the way gravity acts on the particles settling in water or air. This means that when we see layers that are tilted or folded, it indicates that geological forces, such as tectonic activity, have later moved or deformed them. In essence, sediments settle evenly, forming horizontal layers, and any deviation from that indicates subsequent geological processes. This principle helps geologists determine the relative age and the history of Earth's surface features.