New age metals: the geology and genesis of ores required for a changing economy and a carbon-constrained world—preface to a thematic issue on critical commodities

Over the last decade or so, the development of technologies associated with consumer electronics, renewable energy, and specialty steel have sparked demand for a range of “specialty” mineral commodities. These commodities are quite diverse and include, among others, rare earth elements, (REEs: lanthanides, Y, and Sc), Ga, In, W, platinum group elements (PGEs: Ru, Rh, Pd, Os, Ir, Pt), Co, Nb, Mg, Mo, Sb, Li, V, Ni, Ta, Te, Cr, Mn, Se, Ti, Sr, graphite, Sn, Ge, Be, Zr, Bi, F, and Cd. Most of these commodities have small, restricted markets, and, in some cases, supply is restricted—concentrated in either a small group of countries or producing companies. Some elements, such as In, Ga, Cd, Se, and Te, are produced as by-products of the extraction of base metals. Although the amount of these commodities produced can be quite small (annual global production of Re, for example, was ~50 t in 2012: www.comtrade.un.org/db), they can be highly critical for some manufacturing industries. Consequently, a number of countries, including USA (United States Department of Energy 2010), UK (British Geological Survey 2012), Japan (JOGMEC 2010), Korea (Bae 2010), the European Union (European Commission 2010), and Australia (Skirrow et al. 2013), have commissioned reports on critical commodities. Most of these reports concentrated on economic aspects, with few discussing the geological occurrence of critical commodities. Although the details differed, most of these reports identified REEs (particularly heavy REEs), Ga, In, W, PGEs, Co, Nb, Mg, Mo, Sb, Li, V, Ni, Ta, Te, Cr, and Mn as being highly critical (see Skirrow et al. 2013 for summary). Interestingly, some of these reports identified more traditional commodities, such as Zn, as critical. This Thematic Issue is the result of a symposium at the 34th International Geological Congress in Brisbane, Australia in August 2012 entitled “New age metals: the geology and genesis of ores required for a changing economy and a carbon constrained world”. The purpose of this symposium was to discuss the geology and, to a lesser extent, the economics of critical commodities. This thematic issue presents some of the results of this symposium and related research. The first paper in this issue (Simandl 2014) presents an overview of the geology and market dependency of REE resources. This analysis indicates that in recent years, changes in Chinese government policy have had a major impact on the supply and price of REEs, and that the production of these elements is highly dependent upon metallurgical characteristics and the ratio of heavy to light REEs in the ores. At present, most REEs are produced from carbonatite and related alkaline rocks. Recycling of these elements is in its infancy. Geological and geochemical descriptions of the Cummins Range deposit in Australia and of Bastnästype deposits in the Bergslagen district in Sweden are presented by Downes et al. (2014) and Holtstam et al. (2014), respectively. Important results from the Cummins Range deposit include recognition of shear zone-hosted, REE-rich apatite-monazite-(Ce) rocks formed by the hydrothermal remobilization of REEs from carbonatites within the complex, and that the carbonatitic melts were derived from a subductionEditorial handling: B. Lehmann