Briefly, tell me the history of these rock layers.
3 layers were formed, an earthquake occured, then erosion smoothed the top layer. Two more layers formed after that.
Can you determine the relative age of the "X" fossil? Explain your answer.
No. You cannot determine relative age of a fossil that is present in every rock layer.
What kind of environment did this organism live in? How do you know?
It lived in an aquatic environment. I can see the paddle-shaped limbs used for swimming in water.
What is the relative age of the star fossil?
older than 50 million but younger than 300 million years old
This fossil was found in the desert. How did it get there?
The land must have been under the ocean when the crab was alive. Over time, the environment changed from aquatic to terrestrial.
Which layers are the same age? How do you know?
A&G, C&F, and D&E. I know because their fossils match.
Name at least two ways that these rock layers have been changed.
1. Earthquakes cracked the rock layers, 2. heat and pressure caused the bends, 3. the uplift of the earth caused them to slant
Which organism fossilized most recently?
D. The fish fossil
What caused the rock layers in the canyon to be revealed?
A flowing river weathered and eroded away the rock, forming the canyon and allowing us to see the rock layers.
What will happen if layer E is eroded away?
possible answers: all of the information contained in layer E will be missing, the next rock layer will be deposited on top of layer D, ...