1. What is an orebody?
Mineral deposits vary dramatically in size, shape and mode of occurrence. The methods used to locate, measure and exploit mineral deposits vary equally widely.
In mining, a mineral deposit being exploited or considered for extraction is loosely referred to as an orebody. Orebodies may occur in the form of narrow sheets, pipes or large masses. They may be relatively regular in shape or very irregular in shape and dimensions. They may occur in consolidated form or as soft deposits, spread out on surface, lie close to surface or at considerable depth below surface, and may be horizontal, steep dipping or inclined at any angle in between. These characteristics are determined by the geological nature of formation of the deposit, and all of them influence the design of mines and processes to extract them safely and economically.
Mining is a three-dimensional activity. For discussion of technical aspects of mining, it is important to have a clear understanding of plans and sections. The notes in this section will make frequent reference to plans and sections.
A plan is a projection onto a horizontal plane, like a map. It is the view looking vertically down on an area.
A section is a projection onto a vertical plane, the view looking horizontally at an area, like looking at a building from the side or front, on a TV screen or computer monitor.
Note that plans and sections are drawn to scale, for example:
1:500 (1cm = 500cm = 5m)
1:1,000 (1cm = 1,000cm = 10m
1:5,000 (1mm = 5,000mm = 5m) etc.
Modern software allows engineers to model mineral deposits and mine excavations in three-dimensions and to view them from all directions, to draw plans and sections on any plane and to manipulate these views.