Different types of granite make up the continental crust and scientists often refer to it as "sial," which means silicate and aluminum. Together, these layers make up the uppermost part of the earth t… Although both go through changes during the subduction process, the continental crust is rarely completely destroyed during subduction. Also, they are made up of different rocks which affect their density. Some scientists estimate that some areas of continental crust could be as old as the Earth. Density Differences
The difference between oceanic and continental crust rock material is the density and explains why the oceanic crust is beneath the ocean's surface while continental crust can rise into the Earth's atmosphere in the form of mountain peaks. Like the oceanic crust, the continental crust is destroyed by the subduction process but goes through more partial melting processes than the oceanic crust, allowing it to maintain its lower density and remain above the ocean.