Dave has just informed everyone that the black rocks, which formed by cooling of a very hot lava flow, are much younger than the red rocks, which formed from sediments deposited in a lake. he has examined the red rocks and found that they have not been "cooked" by heat from the black rocks, so the red and black rocks must have been placed together after the black rocks cooled. and, he has examined the contact between red and black rocks and found that it is a fault that has been scratched by the motion of the rocks along the fault. it is likely that: