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

e.mccormick · Answer

The very definition of a dike answers this: http://geosurvey.state.co.us/geology/igneousrocks/PlutonicIgneousRocks/Dikes/Pages/Dikes.aspx

anonymous · Answer

after the sandstone formed and before erosion revealed the canyon wall
The sandstone was there, the dike formed and then the dike caused the erosion to the wall.