Question

diffence between sial and sima

Answer 1

  Sima is the name for the lower layer of the Earth's crust. This layer is made of rocks rich in silicates and magnesium minerals. Typically the sima when it comes to the surface is basalt, so sometimes this layer is called the 'basalt layer' of the crust. 

Sial is the name for the upper layer of the Earth's crust, which is also known as the continental crust because it is absent in the wide oceanic basins. This layer is made of rocks rich in silicates and aluminium minerals.Sial runs between 5 km and 70 km deep.

Answer 2

Sial is composed of silicon and aluminium.It is upper layer which forms a discontinuous cover over the Earth's crust and is entirely absent the ocean floor. Sima is composed of silicon and magnesium. This is the second layer below sial which forms the ocean base. It is also called oceanic crust.