In the previous post
, I introduced a riddle in the form of an unusual looking watch with a curved face. Chris Lee, an ex-SRK colleague and a seasoned structural geologist from Vancouver, correctly identified that the watch cannot possibly operate because it is physically impossible.
As I said in my reply to Chris' comments, the problem is that the hands are too long and they would interfere with the operation of the watch when they sweep the curved face of the watch. The hands would have to be straight at the 3 and 9 o’clock positions, but they have to be curved at the 12 and 6 o’clock positions, which would be impossible if the watch hands are made of stiff metallic material.
So the watch is perfect as a static image, but as soon as you imagine it working in your head, you realise the watch will not work. The watch fails miserably as a model of a real working watch.
The unaltered original image of the watches is shown below, and as you can see the hands are short so that they remain free to rotate in the flat portion of the watch face.
Functional design in geological modelling
The point of all this is that geological models can be either designed to function, or designed ignoring function. I have found that many geological models in the exploration and mining industry were not designed to function from a geological point of view. The difference between a good looking working model and just a good looking model is so subtle it requires a trained expert eye to spot the difference, just like the attentive eye that is required to spot what was wrong with the original picture of the watch. If you do not pick the difference, then it may mean the difference between a deposit that will be profitable, or a deposit that will not live up to its expectations.
Applying the concept of functional design in geological interpretation and modelling is something not many geologists have really paid much attention to, or even thought relevant. Personally, I think that a functional model is absolutely essential in successful exploration and mining because the geological model will impact all downstream activities such as resource estimation, near mine exploration, and mine planning. I will cover this topic in more detail in future posts.
So what can we learn from the watch riddle?
I think this is a neat parable that reminds us of the following important points:
- Geological models and interpretations must be geologically functional. Almost all geological models used in the exploration and mining industry are entirely focused on producing a model that works for resource estimation, and that's about it. This is a very restricted, narrowly focused form of model construction, and has only a limited use. A more flexible widely applicable modelling strategy is constructing a model that is functional in terms of the cumulative geological history that it represents. If you do this as a base, the model will also be useful for various purposes including resource estimation, exploration, geometallurgy, geological engineering applications, and so forth. If you ignore geological functionality you run the risk of getting everything downstream wrong, yet you won't hear about this point in the assessment of mining risk!
- Wind back time when assessing geological models. Most geological models are viewed and thought of as static objects, but geological patterns at any one place are a cumulative result of multiple past events. It requires the geologist to turn back time and assess what happened at a particular location, and only when you do this do you start to see the flaws in geological interpretations. The people who are suited to do this are structural geologists. Structural geologists are trained to see movies of the past and test possible scenarios in their heads by reading them from the rock record.
- Fast geological modelling software will not be able to help you. Anyone can design a good looking watch, but not many will be able to design a good looking functional watch. Likewise, nothing sensible will be constructed if a geological model is built by a person who is not focused on the structural history. It is irrelevant whether you sectionally digitise a model using traditional software or do it fast with Leapfrog--you will likely make serious mistakes along the way if you ignore structural history. You will not notice the serious mistakes, because the model you construct will look great, just like the picture of the inoperable watch. Someone once said to me “Leapfrog is the fastest way to get to the wrong answer”, and I completely understand what exactly he was referring to.
- Do not rely on authority. Because of the brand logo on the watch, many people may have not questioned the authenticity of the image. This is a useful reminder to ignore the brand of an interpretation or any model. If you see a geological model put forward by a well-known academic, mining company, or an industry expert, do not assume that it is correctly interpreted. Always rely on first-principles to assess the model, and then make up your mind independently. Remember, it only took one honest child in a crowd to point out the Emperor had no clothes!
- Study structural geology. Education is always the key to robust geological interpretation and modelling of mineral deposits. Geological modelling, to me, is not about making 3D shapes, but an extension of traditional structural analysis. Just because software like Leapfrog generates shapes from drillhole data does not mean that anyone will instinctively understand what the shapes mean. If you are not familiar with what deformation can do to a rock mass, I suggest you to get yourself educated in structural geology because deformation is the main control of virtually all mineral deposits.
If you would like us to organise tailored structural geology and/or geological modelling courses for your company, please contact us
Brett will be back from India next week to deliver you his second installment of the drill core orientation