Is Crust Made of Sial?
Yes, the continental crust is often referred to as sial.
Geologists commonly use the term "sial" to describe the rocks found in the continental crust. This name is derived from the two primary elements that are most abundant in these types of rocks: silicate (represented by 'Si') and aluminum (represented by 'Al').
According to geological information, continental crust is largely composed of various types of granites. These granitic rocks are rich in minerals containing silicon (in the form of silicates) and aluminum. Therefore, "sial" acts as a useful and descriptive shorthand for the typical composition of the continental portion of Earth's crust.
Why is it Called Sial?
- Si: Stands for Silicate, a fundamental mineral group in crustal rocks.
- Al: Stands for Aluminum, a key metal abundant alongside silicates in continental rocks.
While the continental crust is characterized by its sialic composition, the oceanic crust has a different, denser composition, being mainly basaltic and richer in silicon and magnesium (often referred to as sima).
