ACTIVITY: RELATIVE AGES
1. Define the law of uniformitarianism:_________________________________________
_____________________________________________________________________
2. The principle of __________________ states that the oldest layers are on the bottom and the
youngest layers are on the top.
3. Some rock layers may be folded, faulted or overturned. What could cause this to happen?
_____________________________________________________________________
4. Some rock layers may be eroded away by water, wind or ice and then new rocks are deposited on top
of the eroded rock layers. What are the buried surfaces of erosion called?
___________________________________________
5. Look at the cross-sectional view of the rock layers below. Decide which layer is older for each
question. Circle the name of the older material:
tan sandstone or brown sandstone
brown sandstone or gray limestone
gabbro dike or brown sandstone
gabbro dike or gray shale
snail fossil or trilobite fossil
snail fossil or dinosaur bone
snail fossil or green shale
dinosaur bone or red sandstone
red sandstone or gray limestone
tan limestone or tan sandstone
tan limestone or gray limestone
6. The type of unconformity shown in the diagram is a(n)_ ___________________