The crust is divided into two layers,namely:
(i) The oceanic crust(sima).
(ii) The continental crust(sial).
The crust is made up of solid rocks.
The sial is rich in silica and aluminium while the sima is rich in silica,magnesium and iron.
The sima is made up of dense rocks(2.8-3.0 gm/cc.
The sial is made up of lighter rocks of density 2.7gm/cc.It floats on sima. The sial is made up of sedimentary or metamorphic Rocks.
The sial rocks are made of rigid/brittle rocks.
The earth's crust extends between 6 km to 80 km.
maurice.mutuku answered the question on May 27, 2017 at 10:07
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