Question

in the cross - section shown, if layer 2 is 299 - 318 million years old and layer 7 is 488 - 542 million years old, which of these is most likely correct?
layer 4 is less than 318 million years old.
layer 2 is younger than layer 1.
layer 3 is 317 million years old.
layer 5 is younger than layer 6.

Explanation:

In geology, the principle of superposition states that in undisturbed sedimentary rock layers, the older layers are at the bottom and the younger layers are on top. However, when there are intrusions (like Layer 5 which cuts through Layer 6), the intrusion is younger than the layers it cuts through. Layer 2 is above Layer 1, so it is younger than Layer 1.

Answer:

Layer 2 is younger than layer 1.