The two most abundance elements in earth's crust are : silicon and oxygen
the most abundant element in earth's crust is oxygen: 46.6%.
It is found as silicates, carbonates, sulphates etc.
The second most abundant element in earth's crust is Silicon: 27.7%
Mainly it is found as silicates.
The third most abundant element in earth's crust is Magnesium: 8.1%
The fourth most abundant element in earth's crust is Iron: