Radioactive dating is also called
Radiometric dating is a technique used to date objects based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products using known decay rates.
Despite seeming like a relatively stable place, the Earth's surface has changed dramatically over the past 4.6 billion years.
In the Grand Canyon, the layers of strata are nearly horizontal.
Most sediment is either laid down horizontally in bodies of water like the oceans, or on land on the margins of streams and rivers.
Geologists have established a set of principles that can be applied to sedimentary and volcanic rocks that are exposed at the Earth's surface to determine the relative ages of geological events preserved in the rock record.Just as when they were deposited, the strata are mostly horizontal (principle of original horizontality).The layers of rock at the base of the canyon were deposited first, and are thus older than the layers of rock exposed at the top (principle of superposition).Thus, any deformations of strata (Figures 2 and 3) must have occurred after the rock was deposited.Layers of rock are deposited horizontally at the bottom of a lake (principle of original horizontality).