STRIP MINE

Strip mining is a form of surface mining. The ore is close to the surface of the land but has one or more layers of rock and dirt on top of it. To mine the ore, these layers have to be taken off.
The steps in strip mining are like open-pit mining. The steps are:

	The trees and bushes are pushed down by bulldozers.
	This waste, along with the dirt or sand under it, is taken to a nearby area and dumped.
	Lots of small holes are drilled through the rock that is above the coal or mineral bed [vein]
	Explosives are put in the holes and blasted. This breaks up the rock which is taken to the dumping area.
	When the coal or mineral is found, it might be broken up by the blasting. The sizes of the chunks is important because the miners don’t usually want it in tiny pieces. They usually want it in pieces that are able to be moved with large machinery.
	This mining is done in long, narrow strips. When the ore is done in one strip, the miners begin to create another strip next to it. The waste, dirt, and rock that they take off of the top of the next strip is put on top of the last one. This is repeated until the last strip is done and the waste from the first strip is brought back to fill it.

Strip mining, like other kinds of surface mining, ends up hurting the area around the mine. The rock, gravel, trees, vegetation, and dirt are dumped in areas around the mine. When it rains, this runs over the land and into streams and rivers. The rain pushes the mine dirt on top of the area topsoil and buries it. The streams end up being blocked and rivers flood. Water is contaminated by the flooding.
The mined land was usually ruined, too. There were no trees or plants left. The top soil was bulldozed under the rock. It became the cheap and quick way to mine until the U.S. Government made mining companies fix [reclaim] the land when the mining was done. Visit our Mining and the Environment page.
To reclaim land, mining companies have to fix the land and make it like it was before. With strip mining, waste was pushed onto the last strip mined. This ends up making a whole bunch of rows that need to be leveled when mining is done. The mining company has bulldozers flatten the raised strips until they are all even. Topsoil is bulldozed over the top of everything and trees and grasses are planted.

sumber: http://library.thinkquest.org/05aug/00461/stripm.htm