Abstract The primary geophysical methods currently used for nickel exploration in the Yilgarn are magnetic and electromagnetic surveys and, to a lesser extent, induced polarization surveys. This chapter describes the basic principles, optimal strategies, and data interpretation techniques for each method, along with a compilation of the essential petrophysical properties such as conductivity, magnetic susceptibility, and polarizability for the host rocks and ores. A number of detailed discovery case studies are given for deposits and camps including the Kambalda Dome, the Black Swan area, the Cosmos and Waterloo-Amorac areas of the Norseman-Wiluna greenstone belt; the Maggie Hays-Emily Ann area of the Lake Johnston greenstone belt; and the Flying Fox-New Morning area of the Forrestania belt. Early discoveries in the Kambalda-Widgiemooltha area drew heavily on aeromagnetic data to delineate belts of komatiitic olivine cumulates. in more recent times, electromagnetic surveys have played an important role in the discovery of new deposits such as Maggie Hays North, Emily Ann, Cosmos, Waterloo, and Amorac. Surface and downhole transient electromagnetic method (TEM) (also called time domain electromagnetic method, or TDEM) studies have been the most successful methods by far. Rapidly continuing development in instrumentation and interpretation software will only improve the success rate of TEM techniques. Downhole electromagnetic surveys are now the most important methods in locating extensions and new lodes at depth.

Abstract Raman spectroscopy has gone through several stages of development linked with improvements in technology, especially in electronics, lasers, filters and detectors. Many commercially available instruments are easy to use and have become plug-and-play instruments that are now widespread in many Earth science and Cultural Heritage laboratories, but the basic theory on which the instruments are based is often poorly known, which can result in poor use or poor choice of instrument. This chapter is intended to summarize the instrument specifications imposed by Raman spectroscopy and to summarize the basic knowledge and theory for the main components of a Raman spectrometer. The second section focuses on instrument calibration for correct use of the instrument. It contains both theoretical and experimental parts. Finally, different types of Raman spectrometers are described along with their coupling to other techniques such as LIBS and laser-induced fluorescence.