The
mineral exploration industry is increasingly aware of the importance of the
relationship between mineralogical data and geochemical assay results. However,
until recently, the cost and time constraints of most techniques for analysing
alteration mineralogy have precluded detailed alteration studies. These
impediments have been reduced by the development of the Portable Infrared
Mineral Analyser (PIMA), a field portable infrared spectrometer that allows
rapid (in field) and cost effective analysis of alteration minerals including
subtle variations in mineral crystallinity and composition.

A major application of this technology is in mapping
mineralogical variations within hydrothermal alteration systems. Using actual
case study examples this paper introduces two approaches to using the PIMA data:
1. for directly mapping alteration systems and using the
PIMA data to provide vectors to mineralisation, and
2. for establishing empirical relationships between
geochemical data and PIMA spectral data. These applications demonstrate that
this technology can be an invaluable tool for targeting and mapping alteration
and mineralisation.