Director of Mineral Mapping
After graduating with a B.Sc. from the University of Tasmania (1982) and a PhD from the Australian National University (1987), Scott worked as an exploration geologist with RGC, Goldfields, AurionGold, and Placer Dome, before establishing his own consultancy, Mineral Mapping, in 2005. For the last 20 years, he has worked as an independent consultant, specializing in Exploration Geochemistry, particularly in the use of multi-element ICP geochemistry and SWIR analysis to map far-field expressions and alteration mineral zonation patterns around hydrothermal systems.
Since 2018, he has been a part-time collaborator on research projects and a regular presenter in the M.Sc. (Econ Geol) at the Centre for Ore Deposit and Earth Sciences (CODES) at the University of Tasmania.
Brett Davis: Firstly, thanks for giving Coring the opportunity to interview you, Scott. Please take this as a compliment when I say it seems like you have been a geological heavyweight of the mining and exploration industry for a very long time. You have gained enormous respect in the geological community while you’ve been doing it, especially with the way you’ve almost single-handedly revolutionized how we deal with geochemical information. Can you tell us what interested you in a career in geology?
Scott Halley: Way back, at primary school age, I spent weekends with my grandmother fossicking old mine dumps for minerals, digging for agates to cut and polish, sieving and panning in local creeks in North West Tassie for big red zircon crystals, sapphires and spinel. I was hooked from an early age.
BD: Do you get many opportunities to revisit some of your old geological stomping grounds, e.g. the Kalgoorlie region? And have you seen any of your ideas come to major fruition or change radically?
Scott Halley: I moved from Perth back to Tasmania at the beginning of 2018. I have not had a lot of trips back to Kalgoorlie since then. I am constantly amazed at how many new deposits are being found in and around Kalgoorlie, where geologists have been exploring for 150 years. Whenever I hear of some new find, I go back into the data and try to figure out how and why I/we missed it in the past. It is very humbling. One thing I have been doing for fun in my spare time is pasting together all the geochemical analyses I have ever worked on in the Kalgoorlie region to make mega maps of the whole greenstone. That is a real eye-opener.
BD: Is there a particular mineralization style or deposit type that interests you, and why? I know you have a passion for porphyry- and orogenic gold-style deposits, but it seems like you have worked on almost every style of mineralization.
Scott Halley: The principles of chemistry are the same regardless of deposit type, so many of the ideas and skills are transferable across deposit styles. Anthony Harris described porphyries as ‘big dumb deposits’, with predictable zoning patterns and massive footprints.
BD: This is a question I like to ask because the diversity of answers is really interesting. So, leading on from the previous question—everyone has a handful of deposits that have left a mark on them, be it because of the amazing geology, the hideous conditions, the people they worked with, etc. Which deposits do you hold dear, and which ones really were difficult to work on?
Scott Halley: The two deposits, or camps, that I spent the most time working on were Henty and Kundana. My hypotheses around the origins of the Henty system were totally wrong (another humbling experience). Still, we found significant extensions to the system just by geological mapping, drilling, and drawing serial cross sections, and understanding the alteration patterns (no geophysics, no geochemistry). The Kundana camp was the gift that kept on giving. Our mistake at the time was being too conservative with the drilling programs. Haverion is one of the most interesting deposits I have seen. On the bell curve of weirdness, it is two standard deviations from normal.
BD: Do you think that there are any mineral exploration strategies or technologies that are under-employed but could make a big difference to an exploration campaign if people used them more? I’m really keen to see if you can say something outside of the sphere of geochemistry.
Scott Halley: Quite the opposite; we do a bunch of things that are over-employed and not worth doing. Much of the data collected goes into a database and is never looked at again. There are lots of new technologies out there being promoted by snake-oil merchants. When you look at case histories of new discoveries and the techniques used to find them, most of the deposits look bleedingly obvious in multiple data layers—you can pick them from the map patterns, or geochem footprint, geophysical footprint. Greg Hall says, ‘When you start in the right place, everything works. When you start in the wrong place, nothing works.’ We need to do the basic, effective methods, but do them properly. The alteration haloes surrounding orebodies are usually two orders of magnitude larger than the orebody itself. It is hard to find an orebody, but it is relatively easy to detect the footprint of the system. Choose a suitable technique to find the system, then make a robust 2D geology map and 3D model to find the drill target.
BD: Piggybacking on the previous question, how well do you think the different geological disciplines manage to integrate? I’m particularly keen to know what could be done to employ combined structural geological and geochemical approaches because there seems to be a wide gap in our industry. Many of us are captive to what we are good at, and it seems that client companies too rarely employ the services of geochemists and structural geologists at the same time on the same jobs.
Scott Halley: When Mike Christie started at First Quantum, he used to run campaigns at the mine sites and advanced projects. The campaigns would include a structural geologist, 3D modeler, geophysicist, and geochemist, as well as all the site geologists. These were the most fun and productive jobs I ever worked on. It doesn’t happen often enough. As a geochemist, I can also say that we need to collect data that can be used to inform metallurgists and engineers about mineralogy and rock properties. When we work alone, we get part of the story, but not the bit that matters to other people.
BD: You have a consultancy called Mineral Mapping, and client companies stand in a long queue to engage your services. What is the most maddeningly common and frustrating thing that you encounter when you visit a client site and are asked to perform your geochemical wizardry?
SH: Two technical issues: data quality and data management. Think of an analogy from geophysics. In the 1980s, we flew airmag surveys in fixed-wing aircraft with a 400 m (1312 ft) line spacing and 200 m (656 ft) ground clearance. By the 1990s, we used helicopters, 100 m (328 ft) line spacing and 50 m (194 ft) clearance. Now we use drones.
Why, oh why do companies still use 1980s-style digests and analytical methods for geochem data? Also, it is not unusual to spend a massive chunk of time fixing data exported directly from a company database. When I have to do that, it is a pretty clear indication that if the company people had looked at the data themselves, they would have seen the errors.
BD: What projects are you working on now? And what is your level of involvement? Given the current multi-commodity mineral boom, are you doing a lot of work outside of the commodities and deposit styles you have traditionally worked on?
Scott Halley: Well, I am actually semi-retired (LOL). Just for fun, I am returning to the hundreds of databases I have worked on to teach myself about magma chemistry. This is quite fundamental to mineral deposits, and there are not many people out there who know much about it. I am also working on a modal mineralogy calculation so that you can take an assay table with ppm of elements, apply a mass balance calculation, and convert it to weight percent of minerals. I think this will be a game changer in ‘orebody knowledge’. The other thing I am really interested in is building a new spectral (SWIR) interpretation system. We have had a massive explosion in new spectral gadgets, but nobody has done the basic calibrations to properly pick mineral chemistry in the important minerals, particularly white mica and chlorite. We should be able to look at those squiggly lines from a spectrometer and interpret mica and chlorite compositions in terms of K, Al, Si, Mg, Fe2+, and Fe3+ atoms per formula unit. That would totally change the way we look at zoning patterns in mineral systems.
BD: Apart from me, who have been some of the people who have positively influenced your career?
Scott Halley: Simon Gatehouse, my most influential mentor.
Greg Hall encouraged a generation of geologists to apply science to exploration.
John Walshe realizes the limitation in our knowledge of ore-forming systems and calls it out.
John Dilles and Gerard Tripp—the best communicators of geological ideas.
Mike Christie and Jamie Rogers—best exploration ‘team-builders’.
Anthony Harris and Ned Howard—applying some serious science while still being pragmatic explorers.
Markus Staubmann is my tip for an emerging geology superstar.
BD: Has there been any single satisfying moment in your career that rates above all the others?
Scott Halley: At about 6 p.m. one Friday afternoon in Queenstown, Tasmania, 1991, the drill core from hole HP096 landed on the logging table. Everyone else had left for beer o’clock. That hole returned about 12 m (39.37 ft) at 107 g/t Au.
BD: I’ll always ask this question on the flip side of the previous one, typically getting very diplomatic responses. Many of us have interfaced with less-than-savory individuals or experienced toxic workplaces. Have there been any incidents that really disappointed you?
Scott Halley: It is difficult to answer this diplomatically. I don’t like working with people who are primarily motivated by a desire to demonstrate how clever they are at the expense of others around them.
BD: One of the things you are held in high regard for is your capacity to make seemingly complex geochemical relationships and datasets easily understandable to people who aren’t experts in your specialty field. What are the secrets to conveying this information?
Scott Halley: The most important part of being a consultant is the ability to communicate ideas, but it took me a long time to work that out. I like to demonstrate processes by giving real-world examples. The best way to teach something is to give people the tools to work it out for themselves. I still write shit reports.
BD: Time to massage your ego a bit. How many deposits do you think you have looked at? And, just for giggles, give us an idea of how many hyperspectral plots you think you have examined.
Scott Halley: I have a hard drive with about 20 million TerraSpec files. Last time I counted the number of companies I had worked for, it was more than 150, but that was a few years ago.
BD: One topic we commonly talk about but rarely put into print is the health hazards of working in different countries and environments. Has your health ever been particularly challenged, and if so, what happened?
Scott Halley: One memorable trip, I did a back-to-back from Mauritania at +45°C (113°F) to Romania at -10°C (14°F). After finishing Stage 1 in Mauritania, I was sitting in a plane on the runway in Morocco, and I could start to feel my guts rumbling. I survived the flight to Dubai but then spent the six-hour stopover sitting on the dunny, overdosing on Imodium as fast as I could. It worked, just in time. Landed in Romania, and my luggage arrived two days later. Luckily, I had the foresight to put my down jacket in my carry-on luggage.
BD: This is a standard question of mine because it never fails to elicit really interesting and important answers. If you had abundant financial funding, is there a fundamentally annoying geology question you’d like to solve or a topic you’d like to work on?
Scott Halley: You shouldn’t have asked this question, Brett. I could fill an entire issue of this magazine, giving my suggestions about what we need to do in research space to help make new discoveries.
Researchers, government bodies and companies need to collaborate on themes that will lead to an increased rate of new discoveries. I have a very long wish list. Lots of researchers do academically interesting stuff that will never contribute to a new discovery, but companies support them, looking for the next silver bullet. I am not interested in the isotopic ratios of unobtainium in minerals that are rarely found in nature, but 40 years after the first PIMA was sold, we still do not have the ability to estimate complete white mica and chlorite compositions from those squiggly lines. This is just a basic calibration exercise that nobody has bothered to do properly.
BD: Let me ask a question about the roles of vehicles that distribute your knowledge. Do you find that media platforms such as LinkedIn have helped in the promotion and understanding of geochemistry? And do you think that societies such as the Society of Economic Geologists (SEG) have moved with the times in terms of interfacing your work with the huge population of industry geologists?
Scott Halley: I have been presenting short courses for CODES as part of its M.Sc. (Econ Geol) program for 13 years. I put a lot of work into those, and I rarely present the same material twice. After a while, I started putting some of those on my website and giving them away. The other thing that happened to me some time ago was that I had prostate cancer. My experience with the medical system in Australia was quite traumatic, so I was keen to contribute to a nonprofit organization that voluntarily tries to make life easier. I ran a series of professional development courses sponsored by companies as fundraisers for the Prostate Cancer Foundation of Australia. I advertised these events on LinkedIn and was amazed by the responses.
Most of the SEG members are industry geologists, but their journal is written by academics, for academics. You won’t find a single paper that shows pathfinder element patterns around a mineral deposit with actual company ICP-MS data, but you will find 100 papers on cerium anomalies in detrital zircons. It is good science, but who does it help?
BD: You are incredibly altruistic with your knowledge, as evidenced by freely disseminating conference presentations, papers and tutorials on your Mineral Mapping website. What is your opinion about people ‘giving back’ to the industry and how they should go about it?
Scott Halley: If Simon Gatehouse had not taught me about chemistry in the 1990s, I would not be doing what I do now. You asked before about people working in siloes; there is not enough crossover between universities and industry, and our geology departments are rapidly shrinking. Graduate geologists will not find out about the skills they need in the real world until they start an industry job. I feel like I have an opportunity to pass on some knowledge and help prepare them to contribute to the industry (that is a nice way of saying that I am passing on my cognitive bias).
BD: Now, to some personal questions. Does Scott Halley get any time away from work? If so, what does he do in his downtime? For example, I heard a rumor you are an accomplished flamenco dancer and biscuit maker, but I rarely believe scuttlebutt!
Scott Halley: I moved back to Tasmania because I like the great outdoors. I am spoilt for choice between hiking trails, sea-kayaking, rafting down the rivers, or cycling around country roads that are almost free of traffic.
BD: I know Scott Halley is trying to retire and has a small plot of land. So, a multipronged question: Are you ever going to compile your memoirs and do you have a favorite farm animal (I ask because you commonly mention goats!).
Scott Halley: Memoirs… I have often thought about the need to write a new geochemistry textbook, but that thought never lasts for more than a nanosecond. It is easier to publish more tutorials online.
Favorite animals: I am not into farm animals, but we have an abundance of native fauna here. We have heaps of wallabies, Tasmanian native turbo chooks, possums, and echidnas in the backyard, sea eagles, Australia’s biggest penguin rookery 2 km (1.2 mi) away along the coast, and migrating whales and dolphins just offshore.
BD: Finally, any concluding comments or words of wisdom from an industry veteran?
Scott Halley: I am learning new things faster now than I ever did before. It has just come around decades too late.
For more information visit: scotthalley.com.au
