In geology, deposits are areas in which large amounts of a mineral or a group of them are found. Generally, when the existence of a geological deposit is discovered, a mine is established, that is, a series of prudent excavations are carried out, so that a series of workers can dedicate themselves to the extraction of the minerals found there; in addition, treatment areas for freshly removed materials are included. For thousands of years, mining has been one of the most important economic activities, being the main source of income in countries such as the United States, Russia, Chile, Mexico, Peru and Colombia.
The oldest known mine is located in Swaziland, an independent region in southern Africa; It dates from around 43,000 years ago and it is believed that it was used by the primitives to make weapons or various objects of value for hunting and gathering food. In America, a mine located in Chile is 100 centuries old, which makes it the oldest in the entire American continent. For many years, the mining industry was one of the main economic rents in the world, since it was the main source of raw material, for a society that was starting an industrial revolution.
These excavations can be divided into two groups: open pit mines and underground mines. The ones that are superficial, are characterized by carrying out the work with much heavier machines; An example is the Cerrejón, in Colombia, classified as the largest in the world, with 69,000 hectares. Those that are underground tend to be divided into galleries, and the work is done with men.
