MINERAL DISCOVERY IN KNOWN AND AS-YET-UNKNOWN MINERAL SYSTEMS

Individual ore deposits are the result of mineral systems that generally include a metals and sulfur source, a means of element transport, a chemical and/or more rarely physical trap, and the energy required to enable the system. Research during the 20^th century led to reliable models for some mineral systems such as those for porphyry copper and volcanogenic massive sulfide deposits. Developing robust mineral systems models are a key to future mineral potential evaluations of both mature and under-explored regions. Due to our focus on the economically productive portions of the mineral system (i.e., the mineral deposit itself), we have less understanding of the broader geologic components of many mineral systems including systems that are relatively well understood. The sedimentary rock-hosted stratiform copper system provides an example of the challenges in developing more holistic mineral system models. Perhaps even more intriguing for mineral exploration in the 21^st century will be development of models for as-yet-unknown mineral systems. The discovery of the Olympic Dam deposit in the late 20^th century spurred development of new mineral system models and continued chance discoveries, such as that of the HREE-rich clay deposits of southern China or the Enterprise sediment-hosted nickel deposit in Zambia, illustrate that we must continue to be open to investigating currently poorly understood processes for mineral deposit formation.