The technological world around us is becoming more advanced and compact every day, with the processing power of a desktop computer from a decade ago now fitting into your smartphone. The exploration industry is taking advantage of this: many traditional analytical techniques that once required the use of a fully equipped lab are now available in portable, often handheld, devices.
Portable X-ray fluorescence (pXRF) analyzers have been on the market since the latter part of the 20th century, but it is only with the advent of safer and more convenient instruments, which did away with an isotope X-ray source, that there has been a surge in interest. These instruments may have taken off a little too fast, as the capabilities of the first generation of instruments were somewhat oversold; inexperienced operators lacked the guidance to identify flaws and limitations in their data, leading many to dismiss pXRF as a passing fad. However, instruction on practical operation and application of the instruments has been addressed by detailed studies undertaken by the Canadian Mining Research Industry Organization and the Geological Survey of Canada, among others. As well, the instrument manufacturers have significantly improved the capabilities and userfriendliness of their products.
Today’s pXRF instruments – from respected manufacturers such as Olympus, Thermo Scientific and Bruker – are integrated with many geochemical software packages, and can produce reliable and reproducible data with careful consideration and minimal sample preparation. As more exploration managers become familiar with the capabilities (and limitations) of these instruments, their value in providing real time geochemistry for rapid decision-making, for reducing the cost of sample-heavy regional surveys, and for screening samples prior to commercial assay, will almost certainly mean that any geologists working in mineral exploration will eventually find themselves using one of these devices.
The idea even 10 years ago that isotope analyses could be conducted on a mine site or in a field camp was geo-fantasy.
For more than a decade, geologists have also utilized the powerful, nondestructive mineral identification capabilities of shortwave infrared (SWIR) spectroscopy during mineral exploration. This technique can distinguish clays and other minerals that delineate zones of hydrothermal alteration, or can be used to aid efficient ore processing during mine production. However, previous instruments, while technically backpack portable, were cumbersome and required experienced operators with detailed understanding of spectral interpretation to produce reliable and accurate data.
The TerraSpec Halo from PANalytical (formerly ASD Inc.), which was launched earlier this year, addresses both of these limitations. Within the handheld TerraSpec Halo, a full-range near infrared pectrometer – covering visible light to SWIR wavelengths – is coupled to proprietary spectral analysis software to produce fast mineral identification without having to subsequently process the data. In a point-and-shoot operation, the TerraSpec Halo can produce a semi-quantitative breakdown of the mineral content of a sample within seconds. An onboard GPS unit tags each data point collected, and the underlying raw spectra can be exported to laboratory-grade software for a more detailed analysis.
The Mineral Deposit Research Unit at the University of British Columbia has delved even further into the geochemist’s toolbox, having developed a bench-top isotopic analyzer. The Mineral Isotope Analyzer (MIA) is capable of determining the carbon and oxygen isotope composition of powdered carbonate veins and altered whole rocks that are then reacted with phosphoric acid at elevated temperatures. Although this technology is not truly portable, the idea even 10 years ago that isotope analyses could be conducted on a mine site or in a field camp was geo-fantasy. The power of these isotope systems to map alteration halos around a variety of ore deposits has been demonstrated through numerous studies, but has always been out of reach in a standard exploration program due to the cost and time involved. The development of the MIA opens the door to such studies being conducted while a drill program is underway, and could direct drill hole targeting in real time. Drill hole alignment has also gone portable with the Reflex TN14 Gyrocompass, which can be single-handedly attached onto a drill rod.
Drill hole co-ordinates can be entered either on site or remotely, and the TN14 works both on surface and underground. The ease of transport and use, coupled with accuracy and a diverse range of environments that it can be used in, make it an appealing piece of equipment for any drill program that requires precision drilling.
These devices are in the vanguard of a march toward increasingly portable exploration equipment, and the possibilities of the next decade of development are, as is often said, almost unlimited. One characteristic of every one of these technological marvels remains the need for a human – not just to operate the equipment, but also to interpret the results. This should provide some comfort in the current economic climate that technically trained professionals won’t be replaced by geo-robots just yet.