Depth of Occurrence
Exposed to surface
Mineral deposits like iron ore, bauxite, chromite, copper, limestone and magnesite are exposed to the surface and easy to explore. Although most of the significant exposed ore deposits, namely, Example Outside the Sterling Hill Mine are exposures of the weathered surface of the zinc ore body in the Passaic Pit. Calamine (zinc silicate) was mined in this oxidized portion of the ore body. Canon City, USA.
Deposits like base metals, coal and gypsum are covered by altered oxidized capping or exist at shallow depth or under thick overburden of bedrock. The deposits are Cerro de Maimon copper-gold deposit at Dominican Republic, Geochemical prospecting and ground geophysical survey will be helpful for discovery of deposits at shallow depth.
Deep-Seated Hidden Deposit
Deep-seated hidden deposits will be the future target of mineral exploration. The key exploration procedures suitable for discovery of an orebody at a depth range of 300-700 m require clear understanding of regional structure, applications of high penetrative geophysical methods and interpretation by simulation tools to identify, describe and delineate. Exploration for such deposits is expensive and associated with considerable economic risk. The high costs result from the necessity of expensive instrumentation and extensive drilling at depth. Ex. The hidden poly-metallic deposits discovered in the past are Neves Corvo copper-zinc-tin, Portugal, at 330-1000 m depth, and Sindesar Khurd zinc lead-silver at 130 m depth, India.
|Exposed to surface,Shallow depth, Deep-seated hidden deposit|