What is relative age dating in geology

You might wish to start in the Cenozoic Era (65 million years ago to the present) and work back through time, or start with Hadean time (4.5 to 3.8 billion years ago) and journey forward to the present day.No matter "when" you start, don't forget to stop along the way to learn about the stratigraphy, ancient life, fossil localities, and tectonics of the various time periods.The regular order of occurrence of fossils in rock layers was discovered around 1800 by William Smith.Exploring this series of exhibits will take you on a journey through the history of the Earth, with stops at particular points in time to examine the fossil record and stratigraphy.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!Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms.For example, based on the primate fossil record, scientists know that living primates evolved from fossil primates and that this evolutionary history took tens of millions of years.

Your goal is to study the smooth, parallel layers of rock to learn how the land built up over geologic time.Now imagine that you come upon a formation like this: What do you think of it? How can you make any conclusions about rock layers that make such a crazy arrangement?Geologists establish the age of rocks in two ways: numerical dating and relative dating.The Geology Wing is organized according to the geologic time scale.If you wish to begin browsing now, click on any division of the time scale below.