State reasons for variations in type, quality and quantity of minerals.

There are multiple reasons for the variations in type, quality, and quantity in minerals, such as:
- place of formation, on the surface, or inside the ground and how deep inside.
- pressure; extremely important for the structure of the minerals as well as the mixing of mineral types.
- temperature; similar to the pressure, in fact in combination with it, affects the structure of the minerals.
- tectonic activity and volcanic activity; cause the other factors and are also responsible for the quantity of minerals.

Answer// dinosaurs emerged during mesozoic era;