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→Extraction: Rewrite, reimplify the convoluted explanation and make it clear that this is just one method of locating an ore body |
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[[File:Sunrise Dam Gold Mine open pit 11.jpg|thumb|alt=Refer to caption.|Note the angled and stepped sides of the [[Sunrise Dam Gold Mine]], Australia.]]
[[File:Tagebau Garzweiler bei Otzerath Schaufelradbagger Januar2008.ogv|thumb|A bucket-wheel excavator extracting lignite from [[Garzweiler surface mine]] in Germany during 2008]]
Miners typically drill a series of test holes to locate an underground ore body. From the extracted samples, they can determine the extent of the ore. This helps them determine the likely ___location of the veins or benches of ore and its commercial value.<ref name=eb>{{Cite web|url=https://www.britannica.com/technology/mining|title=Mining|website=Encyclopedia Britannica|access-date=2019-04-01}}</ref> Open-pit mines that produce [[building material]]s and [[dimension stone]] are commonly referred to as [[quarries]].{{cn|date=March 2024}}
Open-pit mines are typically enlarged until either the [[mineral resource classification|mineral resource]] is exhausted, or an increasing ratio of overburden to ore makes further mining uneconomic. When this occurs, the exhausted mines are sometimes converted to [[landfill]]s for disposal of solid wastes. However, some form of water control is usually required to keep the mine pit from becoming a lake, if the mine is situated in a climate of considerable [[precipitation (meteorology)|precipitation]] or if any layers of the pit forming the mine border productive [[aquifer]]s. In Germany and adjacent countries several former open-pit mines have been deliberately converted into artificial lakes, forming areas such as the [[Lusatian Lake District]], the [[Central German Lake District]] or the [[Upper Palatinate Lake District]]. A particular concern in the formation of these lakes is [[acid mine drainage]].
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