Here's why:
* Granite is a common igneous rock found in the Earth's crust. It is primarily composed of quartz, feldspar, and mica.
* Continental crust is the outermost layer of the Earth that makes up the continents. It is largely composed of felsic rocks, which are rich in silica, like granite.
While the continental crust contains a variety of rocks, granite is a significant component and a good representation of its overall composition.
