Overburden

Overburden in a coal mining site.

In mining, overburden (also called waste or spoil) is the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above a coal seam or ore body. Overburden is distinct from tailings, the material that remains after economically valuable components have been extracted from the generally finely milled ore. Overburden is removed during surface mining, but is typically not contaminated with toxic components and may be used to restore an exhausted mining site to a semblance of its appearance before mining began.^[1]

A related term is interburden, meaning material that lies between two areas of economic interest, such as the material separating coal seams within strata.^[2][3]

Analogous uses

Overburden may also be used as a term to describe all soil and ancillary material above the bedrock horizon in a given area.

By analogy, overburden is also used to describe the soil and other material that lies above a specific geologic feature, such as a buried astrobleme, or above an unexcavated site of archeological interest.

In particle physics, the overburden of an underground laboratory may be important to shield the facility from cosmic radiation that can interfere with experiments.

In arboriculture, the word is also used for the soil over the top of the roots of a tree collected from the wild. It can denote decades of fallen needles, leaves, and other materials that fall over the top of a tree's roots in the wild.

See also

• Gangue
• Spoil tip

Notes

1. Kogel, Jessica Elzea (editor) (2006) Industrial minerals & rocks: commodities, markets, and uses (7th edition) Society for Mining, Metallurgy, and Exploration (U.S.), Littleton, Colorado, page 379, ISBN 0-87335-233-5
2. United States Bureau of Mines (1980) Selective Interburden Handling Techniques National Technical Information Service, Springfield, Virginia, OCLC 42983831
3. Peng, Syd S. (1986) Coal Mine Ground Control (2nd edition), Wiley, New York, page 303, ISBN 0-471-82171-3

References

• Bates, R.L., and Jackson, J.A., (1987) Glossary of geology American Geological Institute, Alexandria, Virginia.
• Haering, K. C.; Daniels W. L. and Roberts J. A. (1993) "Changes in mine soil properties resulting from overburden weathering" Journal of environmental quality 22(1): pp. 194–200.
• McFee, W.W.; Byrnes, W.R. and Stockton, J.G. (1981) "Characteristics of coal mine overburden important to plant growth" Journal of environmental quality 10(3): pp. 300–308.