Relative Age of Rock, Fossils and Events

Warm Up- snowball What is the difference between relative age and absolute age of an object?

Absolute age: the actual age, in years, of rock or a fossil found by radiometric dating Relative age: the age of an object or event in comparison with another

Which layer of rock do you think is the oldest and which do you think is the youngest? Explain why you think that.

The Law of Superposition: in undisturbed sedimentary rock layers, older layers lie under younger rock layers.

How does this help us determine the age of fossils?

The principle of crosscutting relationships, which states that an igneous intrusion is always younger than the rock it cuts across. A   B C  D

Practice Put the letters of the layers in order from oldest to youngest. If any of the letters represent anything other than sedimentary rock, list what they are. Also, tell when/where any events occurred.

Do you get it?