Answer:
 (1) silicon, oxygen, and one or more metal elements 
Step-by-step explanation:
The earth's Crust is mainly composed of 
Oxygen, Silicon, Aluminum, Iron, Calcium, Potassium, Sodium and Magnesium. 90% of the earth's Crust is composed of Silicates.
The earths Mantle is almost completely Silicate, oxygen and magnesium.