What is "erosions"

Usage examples of "erosions".

Biologists still mourned the mass extinctions of native species that had followed, the erosions and droughts and floods, but really, Miles thought, over the centuries of the Time of Isolation the fittest of both worlds had fought it out to a perfectly good new balance.

You were about to further explain the good results proceeding from the erosions and disintegrations effected by the Third Degree.