Mineral Exploration is the official publication of the Association of Mineral Exploration British Columbia.
Issue link: http://digital.canadawide.com/i/370216
F A L L 2 0 1 4 15 T he 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 smart- phone. The exploration industry is taking advantage of this: many traditional ana- lytical techniques that once required the use of a fully equipped lab are now avail- able in portable, often handheld, devices. Portable X-ray fluorescence (p XRF) 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 instru- ments may have taken off a little too fast, as the capabilities of the first generation of instruments were somewhat oversold; inexperienced operators lacked the guid- ance to identify flaws and limitations in their data, leading many to dismiss p XRF 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 signifi- cantly improved the capabilities and user- friendliness of their products. Today's p XRF instruments – from respected ma nufact u rers such as Olympus, Thermo Scientific and Bruker – are integrated with many geochemical software packages, and can produce reli- able and reproducible data with careful consideration and minimal sample prep- aration. As more exploration managers become familiar with the capabilities (and limitations) of these instruments, their value in providing real-time geo- chemistry 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 geolo- gists working in mineral exploration will eventually find themselves using one of these devices. For more than a decade, geologists have also utilized the powerful, non- destructive mineral identification capa- bilities of shortwave infrared ( SWIR) spectroscopy during mineral explora- tion. This technique can distinguish clays and other minerals that delineate zones of hydrothermal alteration, or can be used to aid efficient ore processing dur- ing 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 infra- red spectrometer – 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 opera- tion, the TerraSpec Halo can produce a semi-quantitative breakdown of the min- eral 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 soft- ware 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 compo- sition of powdered carbonate veins and altered whole rocks that are then reacted with phosphoric acid at elevated tem- peratures. Although this technology is not truly portable, the idea even 10 years ago that isotope analyses could be con- ducted 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 stud- ies, 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 tar- geting in real time. Drill hole alignment has also gone por- table 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 equip- ment for any drill program that requires precision drilling. These devices are in the vanguard of a march toward increasingly portable exploration equipment, and the pos- sibilities of the next decade of develop- ment are, as is often said, almost unlim- ited. 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 com- fort in the current economic climate that technically trained professionals won't be replaced by geo-robots just yet. • Analytics on the go PORTABLE VERSIONS OF TRADITIONAL TOOLS ARE MOVING MINERAL ANALYSIS FROM THE LAB TO THE FIELD By LiBBy ShaRMan The idea even 10 years ago that isotope analyses could be conducted on a mine site or in a field camp was geo-fantasy.