GEOLOGY:
How to Concentrate Copper
Jean S. Cline
Porphyry copper deposits, which supply nearly 60% of the world's copper, form as upper-crustal magmas crystallize and exsolve metal-bearing hydrothermal ore fluids. However, few upper-crustal magmas produce economic copper concentrations. In her perspective Cline discusses work by Harris et al. that examined silicate melt and fluid inclusions from the Bajo de la Alumbrera deposit, in Argentina and revealed processes that may be critical to forming economic, rather than barren, porphyry systems.
The author is in the Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA. E-mail: jcline{at}unlv.edu