Discover how geologists study the layers in sedimentary rock to establish relative age.
Learn how inclusions and unconformities can tell us stories about the geologic past.
We'll even visit the Grand Canyon to solve the mystery of the Great Unconformity!
Imagine that you're a geologist, studying the amazing rock formations of the Grand Canyon.
For each dating or chronological method there is a link in the box at right to take you to that section of this page.
There, you will find a brief description of the method, plus links to take you to other webpages with more extensive information.
Prior to the discovery of radiometric dating which provided a means of absolute dating in the early 20th century, archaeologists and geologists used this technique to determine ages of materials.Relative dating cannot establish absolute age, but it can establish whether one rock is older or younger than another.Relative dating requires an extensive knowledge of stratigraphic succession, a fancy term for the way rock strata are built up and changed by geologic processes.Though relative dating can only determine the sequential order in which a series of events occurred, not when they occur, it remains a useful technique especially in radiometric dating.Relative dating by biostratigraphy is the preferred method in paleontology, and is in some respects more accurate (Stanley, 167–69).The same thing can be done with geologic features in a rock outcrop.To do this geologists use the Laws of Relative Dating.Geologists establish the age of rocks in two ways: numerical dating and relative dating.Numerical dating determines the actual ages of rocks through the study of radioactive decay.The Permian through Jurassic stratigraphy of the Colorado Plateau area of southeastern Utah is a great example of Original Horizontality and the Law of Superposition, two important ideas used in relative dating.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.