Geology

Grand Canyon, AZ March 15, 2020 15:47

We are back at the Grand Canyon to take a closer look. Geology is the study of the Earth’s physical structure. Geologist love studying the Grand Canyon because the cliff walls expose the different types of rock and soil found throughout the region dating as far back as two billion years ago. Geologist place rocks into three different categories: igneous, metamorphic and sedimentary. The oldest rock on the bottom of the canyon is made up of igneous and metamorphic rocks. Above these are layer upon layer of sedimentary rock. The picture below is an example of a stratigraphic column. Geologist use these diagrams to look at the different rock layers. There I am on the Manakacha formation. (beep boop beep). R2 says he is on the Watahomigi Formation.

These stratigraphic columns show the rock layers with the oldest on the bottom, and the youngest on top. In geology, this is referred to as the principle of superposition, which means the rocks on top are generally younger than rocks below them.

Did you know, how old the youngest rock is at the Grand Canyon? The top layer called the Kaibab Limestone, which is the youngest, is about 270 million years old.