Once the choice to mine by underground means has been made, early mine planning decisions are influenced primarily by the size and shape of the ore reserve. Subsequent detailed design takes account of many other factors, but the size and shape of the orebody have overriding influence on mining strategy.
The following isometric sketches with perspective illustrate the main types of ore reserve, from the point of view of mine planning. Straight edges are used for clarity, in reality shape and structure are irregular. Dimensions are only orders of magnitude for comparison purposes. Ore reserves are natural phenomena so do not have neat geometrical boundaries. Nevertheless, most will fit into one of these described categories and as such will have their own unique mine planning features. For instance, most mines with steep, narrow and continuous veins will use shrinkage, resuing or sublevel stoping. Those with thick and flat reserves mainly use room and pillar. Volcanic pipes are mined using block or sublevel caving.