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I’ve been discussing asymmetric mineralisation patterns that I’ve named Perkins Discontinuities, after Bill Perkins‘ observations at Mt Isa, since my third LinkedIn article on VMS deposits published in 2020. In that 2020 LinkedIn article, I described Perkins Discontinuities as a common feature of epigenetic deposits. But until now, I hadn’t published on the topic in a…

Most students wait for opportunity… But Peter, a Year-11 student, simply created it himself. At the year’s end his passionate earth-science teacher announced the news that the subject wouldn’t run in Year 12 —unless Peter could persuade fifteen classmates (and the principal) to keep it alive: “Find the numbers and I’ll run the course”. Earth…

Before the internet and mobile phones—back in the 1990s when I sported a Lady Di hairdo, this is how I measured bedding and other planar surfaces. Hairdos may have changed (thankfully), but my method hasn’t, and that’s what I’m going to share with you today. Now, let’s talk gear. I was as student, so I…

This is 𝗣𝗮𝗿𝘁 𝟮 of a two-part series on the structural analysis of mineral deposits. Part 1 was a technical talk delivered by Brett Davis at the Australian Institute of Geoscientists (AIG) GOLD24 Symposium in Perth on 22 October 2024, which can be found here. Brett covered the fundamentals of the “inside-out” method of structural…

This is 𝗣𝗮𝗿𝘁 𝟭 of a two-part series on the structural analysis of mineral deposits. It introduces a technical talk recently delivered by Brett Davis at the Australian Institute of Geoscientists (AIG) 𝗚𝗢𝗟𝗗𝟮𝟰 𝗦𝘆𝗺𝗽𝗼𝘀𝗶𝘂𝗺 in Perth on 22 October 2024. And no, thankfully, there won’t be a live demonstration of breakdancing by Brett ‘K-Matic’ Davis—but…

As a consultant geologist in the mining industry, I’m deeply concerned about the ongoing closures of geology departments across Australia. The Geological Society of Australia’s President, Amber Jarrett , sent an email to members this evening announcing a town hall meeting on Wednesday, 27 November 2024, aimed at fostering dialogue on how to preserve what…

Prologue In the dimly lit back corner of The Blind Geologist, a pub known more for its weathered geological maps on the walls than the quality of its ale, two figures sat hunched over a well-worn table. The air was thick with the scent of wood smoke and the murmur of subdued conversations, but all…

During my recent trip to Toronto in May 2024, I had the opportunity to sit down with Emeritus Professor Ed Spooner at the Faculty Club of the University of Toronto to discuss his career at the university. When I was a postgraduate student at the University of Toronto (or “U of T,” as Canadians call…

OK, I had a few glasses of wine tonight, put on some jazz music, and started to interpret the Thalanga drilling data released by the Sustainable Minerals Institute 16 hours ago. I’ve spent 1 hour looking at the data, so this isn’t my usual careful example of interpretation, but it’s a demonstration nevertheless of how…

“T𝚑𝚎 𝚏𝚘𝚛𝚖 𝚘𝚏 𝚘𝚛𝚎 𝚍𝚎𝚙𝚘𝚜𝚒𝚝𝚜 𝚒𝚜 𝚊𝚕𝚠𝚊𝚢𝚜 𝚒𝚖𝚙𝚘𝚛𝚝𝚊𝚗𝚝… 𝚃𝚑𝚎 𝚏𝚘𝚛𝚖 𝚒𝚜 𝚙𝚊𝚛𝚝𝚒𝚌𝚞𝚕𝚊𝚛𝚕𝚢 𝚒𝚖𝚙𝚘𝚛𝚝𝚊𝚗𝚝 𝚒𝚗 𝚛𝚎𝚙𝚕𝚊𝚌𝚎𝚖𝚎𝚗𝚝 𝚍𝚎𝚙𝚘𝚜𝚒𝚝𝚜, 𝚊𝚗𝚍 𝚗𝚘 𝚎𝚏𝚏𝚘𝚛𝚝 𝚜𝚑𝚘𝚞𝚕𝚍 𝚋𝚎 𝚜𝚙𝚊𝚛𝚎𝚍 𝚒𝚗 𝚊𝚜𝚌𝚎𝚛𝚝𝚊𝚒𝚗𝚒𝚗𝚐 𝚝𝚑𝚎𝚒𝚛 𝚒𝚗𝚝𝚎𝚛𝚗𝚊𝚕 𝚜𝚝𝚛𝚞𝚌𝚝𝚞𝚛𝚎 𝚊𝚗𝚍 𝚝𝚑𝚎𝚒𝚛 𝚛𝚎𝚕𝚊𝚝𝚒𝚘𝚗 𝚝𝚘 𝚝𝚑𝚎 𝚜𝚝𝚛𝚞𝚌𝚝𝚞𝚛𝚎 𝚘𝚏 𝚝𝚑𝚎 𝚌𝚘𝚞𝚗𝚝𝚛𝚢 𝚛𝚘𝚌𝚔, 𝚝𝚑𝚊𝚝 𝚒𝚜, 𝚝𝚘 𝚌𝚘𝚗𝚝𝚊𝚌𝚝𝚜, 𝚋𝚎𝚍𝚜, 𝚏𝚘𝚕𝚍𝚜, 𝚓𝚘𝚒𝚗𝚝𝚜 𝚊𝚗𝚍 𝚏𝚒𝚜𝚜𝚞𝚛𝚎𝚜. 𝙾𝚏𝚝𝚎𝚗 𝚝𝚑𝚒𝚜 𝚒𝚜 𝚎𝚟𝚎𝚗 𝚖𝚘𝚛𝚎 𝚒𝚖𝚙𝚘𝚛𝚝𝚊𝚗𝚝 𝚝𝚑𝚊𝚗 𝚝𝚑𝚎 𝚖𝚒𝚗𝚎𝚛𝚊𝚕𝚘𝚐𝚒𝚌𝚊𝚕…

Why should you read this article? I’ll give you one good reason: Applying my practical methods, the exploration geologists from Sukari Gold mine, a Centamin operation, discovered 130,000 ounces of gold in their underground exploration program in 2022  With this workshop, your company could emulate this success too. Getting out of the Matrix In my…

Exploring the underappreciated role of deposit-scale structural geology in mining, this article outlines the unintended consequence of the dominance of geochemistry since the 1950s. It highlights how neglecting deposit-scale structural analysis has led to confusion and inefficiencies in the industry. This piece serves as a prelude to an article detailing a workshop aimed at empowering…

Recently, I found myself in the crosshairs of some LinkedIn uproar. Apparently, I’m the mastermind behind “junk science” and a wizard of fake news, casting spells of misinformation on unsuspecting young geologists who cannot think for themselves, particularly those who’ve hitched their wagons to Richard Lilly‘s NExUS express. The plot thickens with accusations of me…

Distortional strain (a component of deformation that also includes solid body rotation and translation) is a basic concept of structural geology that needs to be understood by all geologists if they want to eliminate costly mistakes in mineral exploration and mining.  I would estimate that most geological modelling and interpretation blunders made in the mineral…

Into the Red Earth “Drilling cores in the outback at 60, eh, Bruce?” I wiped the sweat from my forehead with the back of my glove. The sun had been relentless today—my 60th birthday. Yet, as a seasoned Western Australian geologist, I should be used to it. Thankfully, the sun was now setting. Mind you,…

The two animations above represent a series of contrasting geological models created from 11 different drilling patterns, all with identical lithological data sampled from a base model with known fold geometry and volume. Those on the left were created using the default settings in Leapfrog software, leading to volumes that vary from −12% to +48%…

When I was an undergraduate studying for my Honours degree in sedimentology back in the early 1980s at Macquarie University, the standard method of analysis was vertical profiling. We would take representative 1D profile sections at different points and try to describe the sedimentological characteristics of the formation under investigation. ‘Facies Models’ by Roger Walker…

At the recent Structural Geology and Resources conference held in Kalgoorlie, Western Australia (18–20 October 2022), Prof Bruce Hobbs gave a paradigm-shifting keynote presentation where he produced an alternative to the 35-year-old Rick Sibson’s fault-valve model. But first, let me briefly explain the background on the fault-valve model. In the introduction to a recent paper…

AusIMM’s Parker Challenge (running from 14 December 2022 to 24 March 2023) was set up to honour the memory of the well-respected American geostatistician, Harry Parker (Searston et al. 2020). I think it’s great the AusIMM organisers came up with this challenge and I believe it’s certainly long overdue. The Parker Challenge is designed to document the…

TRIGGER WARNING: There may be an appearance of certain social media personalities in the video that accompanies this article. This may upset the emotionally fragile. If this happens to you, remind yourself that the world is not coming to an end. Steady yourself, walk slowly and lie down on your comfortable recliner, breathe deeply and…

I wrote this article to explain what I do. Many times I’ve been asked what, exactly, do I do for a living? But it’s difficult to explain because I don’t practice what most applied structural geologists do, and rarely do I get to publish my approach and findings due to the proprietary nature of all…

‘In Japan, best deposits have mudstone in hanging wall’ Donald Singer (descriptive model of the Kuroko massive sulfide) Hmmmm, I wonder why this is the case? Have you wondered about this association of Kuroko deposits being located below mudstones? Interesting, right? Yet you don’t hear much about this in the standard description of the Kuroko deposit. I’ll get to…

‘The Kuroko deposits of Japan are regarded world-wide as the ‘type’ volcanogenic Cu-Pb-Zn-Ag massive sulfides against which all others are compared’ S.D. Scott, 1978, Professor of Economic Geology, University of Toronto Most geologists who’ve taken an ore deposits course would have seen the sketch of the Kuroko massive sulfide deposit, shown above, which has been…

An affair to remember I have a confession to make. I’ve been cheating. I’ve been creating an illusion—pulling wool over everyone’s eyes for a very long time and no one knows about it. I have built this illusion for nearly 20 years through a clandestine relationship with a married woman. But it’s high time I ‘fessed…

Pssst, I have a fun quiz for you! Are you a practical geologist who loves solving geological puzzles? If so, I have a challenge for you in this post—it’s a simple and fun pattern recognition puzzle, and you’ll learn an interesting fact about volcanogenic massive sulfide (VMS) deposits that you probably didn’t know before. Most…

Brett Davis, structural geologist, and I are preparing a paper for a peer-reviewed international journal—this preprint is an abridged version. Because the conclusion is controversial, we would appreciate any constructive feedback to enhance the content, either in the comments section below, or directly to me at jun@juncowan.com. — This is the fourth of a series…

This is the third of a series of posts that provides a counterpoint view of the syngenetic interpretation of ancient Volcanic Massive Sulfide (VMS) deposits, an interpretation that is largely accepted as factual by the economic geology community. The first post is here and the second post here. In the last post, I discussed the…

This is the second part of my series on an alternative epigenetic interpretation of ancient VMS deposits. The first post can be found here. Good News, Bad News I’m actually going to talk about structural geology, which is bad news to most. Yes, I can hear your groans now, but this information is really easy to understand, which is…

This is a prologue to a series of posts that provides a counterpoint view of the syngenetic Volcanogenic Massive Sulfide (VMS) mineralisation model (Jackson, 2017), which is largely accepted as factual by the economic geology community. But a minority of structural geologists, such as Bruce Hobbs and I, doubt the validity of syngenetic models such…

Unbelievable as it may sound, the following account is something that really happened. Only the names have been changed to protect the innocent.   A mysterious gold deposit Between 2004 and 2012, I ran Leapfrog software workshops for clients who had leased Leapfrog software. This meant I travelled to mine sites all over the world, teaching…

The masses never revolt of their own accord, and they never revolt merely because they are oppressed. Indeed, so long as they are not permitted to have standards of comparison, they never even become aware that they are oppressed —George Orwell, Nineteen Eighty-Four We live in an Orwellian society, but we’re not aware of it because…

Resource geologists around the world talk about ‘lithology models’, ‘grade models’, and, on rare occasions ‘structural models’ as if they were completely separate and unrelated features that can be modelled from drilling data. This article discusses this issue—I hope to convince you that this misrepresents reality. Most geologists mean ‘fault model’ (a model that displays…

“We are surrounded by data, but starved of insights” —Jay Baer (American writer) In the Canadian summer of 1987, I arrived in Canada to start my MSc research at the University of Toronto. I was excited about my new life, about seeing interesting sites and making new friends. To escape the sweltering muggy heat of…

The link below is to a video of a talk by Orefind structural geologists Brett Davis and me—Jun Cowan. This talk was given on the 21st of May, 2018, at the Australian Resources Research Centre, Perth, for the Applied Multi-scale Structural Analysis in Mineral Exploration Workshop organised by TeamWA and Geoconferences, and sponsored by Orexplore. We thank…

When we study history we obtain a more profound insight into human nature by instituting a comparison between the present and former states of society. – Charles Lyell, Principles of Geology (1832). Introduction This post is a letter I wrote in 2017 to the Australian Institute of Mining and Metallurgy (AusIMM) after I discovered that…

AI is not the same as big data; AI doesn’t really exist no matter how many companies want to tell you that they are the experts – Roger Schank (pioneer of artificial intelligence and cognitive psychology) ABSTRACT …for those who don’t want to read this very LONG post! There is growing sentiment that artificial intelligence (AI) and…

Is the new Leapfrog Geo 4 now as good as Leapfrog Mining?

Recently I wrote a post about how a 90% mineral resource downgrade could easily occur as a result of bias in the form of habitual behaviour.  People often do not fully realise how extreme or entrenched human bias can be, nor the implications it has with regard to our scientific and business decisions. The purpose of this post…

This article, which originally appeared in Optiro’s website, provides a good summary of AusIMM’s Monograph 30 – The AusIMM guide to Good Practice.

Dr Michael Gipp believes that there is a problem with the current way of publicly disclosing significant intercepts data. He believes the format provides an advantage to financial institutions who can actually model these datasets. The debate is whether to restrict the data, or to open it up for everyone.

Season’s Greetings Youtube video from Orefind

This post has a look at some potential solutions to poor core orientation that occurs at the rig. The single biggest issue is lack of diligence by, and the experience of, the drillers and geologists. Scrutiny of the orientation process needs to be maintained by both drillers and geologists through the life of the drilling programs.

The focus of this blog is to highlight some applied structural geological issues that impact the mineral exploration and mining industry.