Will Give a Medal !
The walls of the Grand Canyon are made of layers of sandstone. A dike cuts across some of the layers. When did the dike form?
after erosion revealed the canyon wall
at the same time as the sandstone formed and the canyon was eroded
after the sandstone formed and before erosion revealed the canyon wall
before the sandstone formed

Question

Will Give a Medal !
The walls of the Grand Canyon are made of layers of sandstone. A dike cuts across some of the layers. When did the dike form?
	after erosion revealed the canyon wall
	at the same time as the sandstone formed and the canyon was eroded
	after the sandstone formed and before erosion revealed the canyon wall
	before the sandstone formed

anonymous · Answer

After the erosion revealed the canyon wall because the question says "layers" which implies that the layers of the canyon walls can be seen, and thus are already revealed. The wall of the cave must be revealed in order to see the dike.

anonymous · Answer

soo the 3rd one?

anonymous · Answer

The first one

anonymous · Answer

Erosion enables you to see the layers, and since the layers are exposed to the elements, the harsh environment can form a dike

anonymous · Answer

@LadyProcrastination Thank You !