The principle of original horizontality states that layers of sediment are originally deposited horizontally under the action of gravity. It is a relative dating technique. The principle is important
The Permian through Jurassic stratigraphy of the Colorado Plateau area of southeastern Utah is a great example of Original Horizontality. These strata make up much of the famous prominent rock formations in widely spaced protected areas such as Capitol Reef National Park and Canyonlands National Park. From top to bottom: Rounded tan domes of the Navajo Sandstone, layered red Kayenta Formation, cliff-forming, vertically jointed, red Wingate Sandstone, slope-forming, purplish
A stratigraphic section of Ordovician rock exposed in central Tennessee, US. The sediments composing these rocks were formed in an ocean and deposited in horizontal layers.