The darker rock represents inclusions of the rock diorite in the lighter colored granite rock of Granite Pass, in Kings Canyon National Park in California.

An inclusion refers to a piece of one type of rock that is contained within another rock type. It is possible to determine the relative age of rock with inclusions compared to nearby rock without inclusions. The neighboring rock must have been there first, and is, therefore, older than the rock with the inclusions since it was the original source for the inclusions.