Question

Hello,
good morning

What is sial and sima​

Answer 1

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.

Answer 2

Answer:

In geology, sima (/ˈsaɪmə/) is an antiquated blended term for the lower layer of Earth's crust. This layer is made of rocks rich in magnesium silicate minerals. Typically, when the sima comes to the surface, it is basalt, so sometimes this layer is called the 'ocean layer' of the crust. The sima layer is also called the 'basal crust' or 'basal layer' because it is the lowest layer of the crust. Because the ocean floors are mainly sima, it is also sometimes called the 'oceanic crust'.

Sima often takes the form of basalt when on the surface

The name 'sima' was taken from the first two letters of silica and of magnesia. Comparable is the name 'sial' which is the name for the upper layer of Earth's crust (continental crust).