Answer:
If I'm not wrong sentence two " You might say that when this
happens, the rock is getting sunburned." and sentence four "But while the rock is buried underground—before running water chews it out of the desert floor—it’s shaded from cosmic rays, so no beryllium-10 develops."
is the the two examples showing personification.
Explanation:
In this sentence: "You might say that when this
happens, the rock is getting sunburned." a rock cannot get sunburned so it's using personification giving human things to non-humans.
and in this sentence: But while the rock is buried underground—before
running water chews it out of the desert floor—it’s shaded
from cosmic rays, so no beryllium-10 develops." It shows personification because it says "before running water chews it out of the desert floor" and we know that water can't chew.