When ice wedging causes a rock to crack in half, it is an example of *

Mechanical weathering.

Explanation:

Ice wedging is a process that happens when water gets into the cracks of concrete, stones, other forms of the Earth, and freezes. When the water freezes, it expands and pushes the rock from the crack which either separates and turns it into two rocks, or the rock might form together again and just be a larger rock. This process happens in Winter and usually finished in Spring when the ice between the rocks melt. I have described the process of ice wedging for you.

That is the process of Ice wedging which shows it is Mechanical Weathering.

dramatic irony is the answer