If a mass of granite is in contact with a layer of sandstone that contains small pieces of the granite, which rock is older?

Question

neither; they are the same age

the sandstone

the granite

Answer 1

The correct answer is the granite.

In geological terms, the principle of cross-cutting relationships states that a rock layer or feature is older than any that cuts through it. If sandstone contains small pieces of granite, it indicates that the granite was already present and then eroded to provide those pieces before the sandstone formed around them. Therefore, the granite must be older than the sandstone.