The ozone layer. The gas it is made of is formed by 3 oxygen atoms.
Answer:
Polar Ice Caps Form.
Explanation:
A subduction zone, is the location of where to tectonic plates meet, and can contain all of the above except for polar ice caps.
The plate boundaries are:
-Convergent
-Divergent
-Transform
I don't know if thats what you meant. Hope It Helps