Consider the following statements and choose the correct option:
1. The Earth's crust is the outermost layer and varies in thickness between 5 km in oceanic crust and about 35 km in continental crust.
2. The crust is mainly made of silica, alumina in continental masses, and silica and magnesium in the oceanic crust.
1
Only statement 1 is correct.
2
Only statement 2 is correct.
3
Both statements 1 and 2 are correct.
4
Neither statement 1 nor statement 2 is correct.