GEOLOGY

Detailed explanation-1: -At its site of generation, magma is lighter than the surrounding material, and consequently it rises as long as the density contrast between magma and surrounding cooler rocks continues. Eventually, magma either solidifies or forms reservoirs at some depth from the Earth’s surface, or it erupts.

Detailed explanation-2: -The lighter silica rich rocks that compose the continental crust form by partial melting of pre-existing denser basaltic rocks. When you partially melt a basalt, the liquid is richer in silica, thus it is less dense.

Detailed explanation-3: -Molten rock, i.e., magma, is less dense and more buoyant than the surrounding rock, as a result magma rises through Earth’s crust. Most magma is trapped in the crust, but some erupts onto the Earth’s surface as lava.

Detailed explanation-4: -This happens because different minerals have different melting temperatures. The melt is less dense than the surrounding rock, and will percolate upward without the source rock having melted completely. The result is magma with a different composition than the original rock.

Detailed explanation-5: -The magma that is produced by partial melting is less dense than the surrounding rock. Magma from partial melting of mantle rocks rises upward through the mantle, and may pool at the base of the crust, or rise through the crust.