What is "strip-mining"

Usage examples of "strip-mining".

For the next three months, you are all assigned to hard labor at the dry lakebeds, strip-mining salt and processing nitrates.

As Leia and Han stood in their formal attire, a greasy rain began pelting down, cold droplets clotted with residue from massive strip-mining operations in industrial sectors far from the showy palaces of the Hutt crime lords.