Solution:
Majority of Earth's crust is composed of igneous rock with about 90% of share. The sial & sima i.e. silica alumina & silica magnesium respective are igneous rock types.

Solution:
Slate is a foliated metamorphic rock that forms from the metamorphism of shale.

Solution:
Nappe, in geology, large body or sheet of rock that has been moved a distance of about 2 km (1.2 miles) or more from its original position by faulting or folding. An extremely folded structure in which the motion of thrust fold overrides the adjacent rock structure is called Nappes. These are found at convergent plate boundaries. Example:- The Himalayan Nappes in Uttarakhand & Nepal.