What do we call the Earth's crust that is less dense and primarily composed of granite?

The Earth's crust that is less dense and primarily composed of granite is referred to as the continental crust. This type of crust is thicker than oceanic crust and consists mainly of granitic rocks, which are rich in lighter elements like silicon and aluminum. The lower density of granite compared to basalt (which predominantly composes oceanic crust) allows continental crust to "float" higher on the mantle, leading to the creation of continents.

Granite's formation process and mineral composition contribute to the characteristics of continental crust, making it essential for the landscape of landmasses, including mountains and sedimentary basins. The continental crust is also where ecosystems and human civilizations primarily develop due to its accessibility and the presence of various natural resources.

Oceanic crust, on the other hand, is denser and mainly composed of basalt. The upper and lower mantle refer to layers beneath the crust and are made up of different materials and densities, neither of which are primarily granite nor form the crustal layer supporting continents.