Answer:
The crust rides upon the mantle and is composed of both the oceanic basaltic-plate and the uppermost continental granitic-plate.
Explanation:
The mantle is one of the four layers that form the earth. It is a very hot and dense rock, that is capable of flow. The crust is the outermost layer of the earth and is located just over the mantle. The crust is divided into many plates, that are able to move over the mantle. In fact, the tectonic plates theory is based on the continual movements of the crust and might explain the movement of the different plates, and their directions and interactions. The continental drift theory explains how these movements have been taken place since millions of years ago.
The crust is composed of two layers characterized by different types of rocks. The continental layer, which is the uppermost, is mostly composed of granite. The oceanic layer, on the other hand, is mostly composed of basalt.
