Absolute dating methods determine how much time has passed since rocks formed by measuring the radioactive decay of isotopes or the effects of radiation on the crystal structure of minerals. Paleomagnetism measures the ancient orientation of the Earths magnetic field to help determine the age of rocks.Absolute dating

How is radioactive dating used to determine the age of an object?

Radiocarbon dating is a method used to determine the age of organic material by measuring the radioactivity of its carbon content. With radiocarbon dating, we see that carbon-14 decays to nitrogen-14 and has a half-life of 5,730 years.

What are the oldest rocks in the Grand Canyon?

Remember, the oldest rocks in Grand Canyon are 1.8 billion years old. The canyon is much younger than the rocks through which it winds. Even the youngest rock layer, the Kaibab Formation, is 270 million years old, many years older than the canyon itself. Geologists call the process of canyon formation downcutting.