The oldest, most stable part of the earth’s crust, the largest being the Canadian Shield
The oldest, most stable part of the earth’s crust, the largest being the Canadian Shield
The super-eon of time until the start of all known life in the Cambrian era, it is the period covering 4500 to 540 million years ago
Potassium ore used for industrial processed and fertilizer
A calcium-aluminum silicate mineral combined with aggregate and water to form concrete