Answer:
Open-pit mining is a type of method for extracting rocks or minerals from the earth .
Step-by-step explanation:
Open-pit mining refers to the method of extracting rocks or minerals from the ground by removing them from an open pit or a digging loan. The term is used to differentiate this form of mining from the extractive methods that require drilling tunnels in the ground - underground mining. Opencast mining is used when commercially useful mineral deposits or rocks are found near the surface; that is, where the thickness of the covering ground (situated above the material of interest, and having to be removed to reach it) is relatively small or the material of interest is structurally unsuitable for opening tunnels (as is the case of sands, volcanic ash and gravel). Where minerals occur far below the surface, and the thickness of cover terrains is large or the mineral occurs in veins in the rock - the material of interest is extracted using underground mining methods. The open pit mines are typically enlarged until the mineral resource (or plot of land owned by the mining company) runs out.