Strip Mining: The term "strip mining" usually refers to a type of mining in which the ground is surface-mined strip by strip. It is only desirable when there is relatively little, soft material on top of the deposits (usually ore, tar sands, or coal).
The earth-moving machines remove the overburden (the material on top of the deposits), moving in a line from one end of the field to another. The excess material is then dumped into the previous strip, such that each new strip is dumped into the prior. This has the advantage of requiring minimal earth-moving for a mine, but the earth, even though it is replaced, usually does not recover for a long time, reaching hundreds of years or more.