Overburden
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Overburden is the term used in mining to describe material that lies above the area of economic interest, i.e., the rock and soil that lies above the coal seam. Also known as 'waste'. 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 a mining site to a semblance of its appearance before mining began.
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.
