There's an open invitation to any Strawman member who is willing to share their insights and experience. But also no pressure.

DMs always open.

It's fairly straightforward @tomsmithidg - as in this example below:

Firstly, the drill holes themselves are not shown on this diagram (above), only the intercepts from those drill holes are shown, meaning where the assays from those drill holes returned significant (reportable) quantities of gold. I will give an example of a diagram showing the actual drill holes later (in this post), which includes the angles of the drill holes.

The grey rectangles are the results of drill hole intercepts from previous quarters and the black rectangles are the results of intercepts from drilling undertaken in the September Quarter - as this diagram is from their September quarter report. So they are showing old (grey) and new (black) results.

The pink shaded areas are their interpreted mineralisation zones, so where they think the mineable gold is based on their drilling results (assays and evaluation) so far.

Question marks means no drilling has been done in that area yet so they have no idea what's there yet.

"Open" arrows mean that the pink mineralisation areas have NOT been "closed off" yet in that direction, meaning the gold MAY continue in that direction - they need to drill there to find out.

"Closed off" means that drilling shows no more significant gold in that direction, and until that has been established the area is considered to be still Open.

Each drill hole has an identifier, such as CVEX063 in the bottom left corner of that diagram above, which stands for Comet Vale EXploration drill hole number 63. In the bottom right we have HJEX009, which is Happy Jack EXploration drill hole number 9. Cheer and Happy Jack are both prospects within the company's Comet Vale gold project, and their biggest discovery so far at Comet Vale has been Lakeview, which is not on this diagram.

Prospects are often identified using various airborne geophysical surveys, such as magnetic, electromagnetic, and gravity surveys, which map subsurface geological features. These surveys are sometimes followed by airborne LiDAR, which creates detailed digital terrain models, and geochemical surveys. This data helps geologists identify anomalies and prioritize areas for ground-based follow-up and drilling. A prospect can also be identified by wide-spaced drilling between or to the side of known gold deposits where that drilling results in promising results suggesting follow-up drilling would be a good idea.

Once a prospect proves to be a significant deposit, they will usually refer to it instead as a deposit, discovery or even a "project" if it looks to be commercially viable. The diagram above is of part of GG8's Comet Vale gold project which includes the Cheer and Happy Jack prospects. Comet Vale is classed as a "project" because of the amount of high grade gold they've already found at Lakeview, which started off as a prospect but is now a discovery that is part of the larger Comet Vale gold project. There's more on Lakeview in my straw yesterday.

Sometimes the drill hole identifiers (ID) will have two letters that indicate the type of drilling used, such as "DD" for diamond drilling (the most expensive type that delivers solid cores that provide the highest quality data), or "AC" for Air Core or "RC" for Reverse Circulation - "DD" forms part of the drill hole ID in the example below from https://nextinvestors.com/learn-to-invest/mining/how-to-read-assays-and-drilling-results-for-beginners/. Those two letter drilling-type identifiers are usually placed directly before the hole number, as in the example below (MNEWDD002) where it is a Diamond Drilling hole. Not every company includes this information in their drill hole IDs.

Plenty more here: Source: https://nextinvestors.com/learn-to-invest/mining/how-to-read-assays-and-drilling-results-for-beginners/

In the examples of drill hole intercepts in the diagram at the top of this post (and repeated below), they are presenting the results in a slightly different format:

Example: "CVEX063 fr. 88m 5m at 2.2g/t Au"

So they are putting the drill hole ID first, followed by the depth of the intercept (fr. 88m" means the mineralisation started from 88m down hole) followed by the intercept details, so they hit 5m of mineralisation at an average grade of 2.2 grams/tonne of Gold (Au).

That example is from the bottom left corner of the example diagram at the top of this post - which I'll repeat here (below).

OK, the following diagram actually shows the orientation (angles) of the drill holes:

As a general rule, when they believe they have vertical veins or thicker mineralisation that is slanting down to the east, they will usually drill down to the west, as shown in this example above, which gives them the best chance of hitting gold in multiple areas of mineralisation and also gives them a decent idea of how thick the gold is in those areas.

In this diagram the drill hole IDs (identifiers) are listed across the top, at ground level, where each drill hole began, and the intercepts are shown down the sides of the diagram with the red ones being the most significant.

The "RC" included in most of the drill hole IDs indicates that those were Reverse Circulation drilling holes.

Diamond drilling (DD) produces high-quality, intact core samples for precise geological analysis, while reverse circulation (RC) and air core (AC) drilling use a percussion or rotating bit to create smaller, fragmented samples that are brought to the surface by air pressure. RC drilling is faster and more cost-effective than diamond drilling for initial exploration, especially in harder rock, and provides less contaminated, higher-quality chips than AC. AC drilling is the fastest and most cost-effective method, but it produces smaller, dustier samples that are more prone to contamination. 

Basically RC results are more reliable than AC results, and DD results are the most reliable of all, better than all other drilling types. But DD is much more expensive so it tends to get used more when a company has already proven that they have a significant gold deposit there, or they are very confident. And cashed up.

The significance of intercepts within drill holes is not just about the grades, for instance an intercept of 2m @ 4.4g/t is not considered to be as significant as 6m @ 3.5g/t because the latter one indicates that the gold mineralisation is three times as thick (6m vs 2m) at that point, so there is more gold there, even though the grade is slightly lower.

One thing I look for is depth of intercepts, so ideally I'd like to see the gold at less than 200m down hole, and lots of it, which would likely mean an open pit rather than an underground mine - which is important because open pits are a LOT less expensive (in terms of development and ongoing costs) than underground gold mines. You need good grades to justify underground gold mining because of the higher costs, but you can often viably mine half a gram/tonne ore if it's close to surface and you can use an open pit.

Generally, depths less than 300 meters are considered open-pittable, while anything deeper requires underground mining. The decision ultimately depends on economic viability, ore grade, deposit size, and geological conditions, as open pits are cheaper for shallow, large deposits, while underground methods are necessary for deeper or more complex orebodies. 

GG8 are finding a lot of gold close to surface and down to less than 200m vertical depth, so these projects are shaping up to be decent open pit gold mines in my view. Many open pits end up going underground as more gold is found at depth, but having enough gold there to justify an open pit to start with is important in this case. GG8 are still early stage, but they're VERY busy and they're spending the majority of their money on drilling and evaluation, and it's paying off, as they stated in this Sept Qtr Report that they've been adding ounces at Mulwarrie at an average cost of just $15/ounce.

When the Aussie gold price is over $6,000/ounce, even after the recent pullback, adding ounces at $15/ounce is brilliant!

Source: https://goldprice.org/

Hope that helps. I gotta go do something else now, away from my office, but hope that answers most of your questions @tomsmithidg.

Fairly straight forward you say @Bear77, yeah, sure thing!!

No wonder @tomsmithidg and others, including me, rely on your expertise and industry knowledge in relation to anything in the mining sector, particularly gold.

You are the SM Guru and I'd also kill to hear you on a pod presso about mining stock analysis. Maybe your pet gold to start with as mining is such a broad topic.

Keep up the great work!!

@Bear77 that was awesome mate, thanks.

Thanks @Bear77 . Appreciate you getting into the weeds to help us understand the diagrams a bit more. The information about the 200m is huge to me as, as this will go a long way to work out what AISC could be expected for some projects.

No probs, however something else that needs to be factored in with future AISC guestimates @SudMav is the type of ore that they're dealing with, for instance oxidised ore is cheaper to process because it requires less expensive, more direct extraction methods, primarily due to weathering processes that have already liberated the gold. Unlike refractory ores, which are locked inside minerals like sulfides and require costly pretreatment (e.g., roasting, pressure oxidation) to expose the gold, oxidized ores have already been broken down. This allows for more straightforward techniques like heap leaching or conventional cyanidation, which use less energy and fewer chemicals. 

We don't have too many large scale heap leach operations here in Australia however it is much more common in some other parts of the world. Saturn Metals (STN) is planning to use heap leaching at their Apollo Hill Gold Project, south east of Leonora in WA, and while they seem to have plenty of institutional backing, the retail punters don't seem to be convinced, or at least that seemed to be the situation last time I looked at them properly. STN has chosen this method (heap leaching) because their deposit's simple metallurgy and low-grade, bulk-tonnage nature are well-suited for the process, which is expected to result in a lower-cost structure compared to conventional milling methods common in Western Australia. 

The large majority of gold mills in Australia are carbon-in-leach (CIL) plants, as it is the most common and efficient method for processing gold ore in the country. Other processes like carbon-in-pulp (CIP), heap leaching, and methods involving biological oxidation or roasting may also be used, but CIL is dominant for the majority of operations, and it's also one of the cheapest as long as the ore is suited to it.

Companies will usually publish metallurgical testwork results and recoveries at some point along with expected process flow charts/sheets, and such studies would always form part of the FS (feasibility study) or PFS (pre-feasibility study) that comes before they get to the FID (Financial Investment Decision) stage and actually go ahead and build a mill. Look out for that, because gold industry metallurgical testwork results are crucial because they determine a project's viability, confirm the expected gold recovery, inform the engineering design of processing plants, and are required to secure financing. Without thorough testwork, a project's economic feasibility could be overestimated, leading to costly design errors, failed operations, or a failure to capture the deposit's full value. For us mug punters it can also indicate whether the project is likely to be a higher or lower cost project, all other things being equal.

The short version is that it's not enough just to know how much gold a company has and how shallow/deep it is. When it comes to costs (AISC or AIC) the type of ore and the chemistry required to liberate the gold, plus the recoveries they may achieve in terms of how much gold they manage to successfully extract from each tonne of ore (% recovery) vs how much gets through into their tailings (waste slurry) matters a LOT.

There are other Strawman Premium members here with engineering and/or mining company analysis backgrounds that know a heap more about that side of things than I do, and one of those people is @BkrDzn who has presented plenty of info here on individual companies and also in the penny stock forum:  Sub 2c Stocks - The Punters Forum. Josh absolutely has a far better handle on the geology and the engineering side of gold mining than I do, so if interested, please check his content out - even if the companies that he is discussing don't interest you personally, there's heaps of knowledge to be gained from reading his analysis on them. And when he uses a term, abbreviation or acronym that has you stumped, do what I have done many times and google it. I've learned a heap from @BkrDzn but he's got many years of experience in that field over me so I don't expect to ever be at that level, despite learning something new most days.

In terms of me presenting anything here in person, that's not going to happen. I'm a real introvert when it comes to that sort of stuff. @Strawman has previously extended an open invitation to me to do something along those lines but I have politely declined, and will continue to do so. There are a bunch of reasons for that, one is that I become forgetful about details sometimes and need to double check those as I'm typing, having multiple tabs open on my browser to check that what I'm saying is actually correct, or even how to spell something - you'd think I'd be getting better at that at 4 months short of 60 but not everything improves with age, and memory is one of the those things.

I was also managing other people's money for almost 7 years, until we wound up that fund last year, and that was under an ASIC exemption from the need to hold an AFSL (commonly known as the 2/20 Exemption) that had a number of rules including not raising (or adding capital of) more than $2 million per year or rolling 12-month period, all members had to be family or associates (known to me), there could not be more than 20 members, and I could not advertise the fund. The rules have changed since we started that fund - e.g. these days only wholesale investors can participate, excluding retail and sophisticated investors. Anyway, we made the decision to wind the fund up last year (sell everything and distribute the proceeds to the members) mainly because I no longer wanted to be responsible for managing other people's money. That said, I still manage my own family's money, just not that of other families that are not directly related to me by blood. Less stress for me, and I needed to reduce stress.

Interestingly, the most profitable period of my investing journey has been the last year of that fund (being FY2024) and the period since, but that period has coincided with a fairly decent gold bull market and me being overweight gold producing companies.

Point being, I don't have that restriction any more, but I still don't want to do a live or recorded interview or meeting. If I ever change my mind (I doubt I ever will), I'll let Andrew know. It's just not my style. Sometimes I take hours to do a forum or straw or val that might take just minutes to read, other times I'll be quicker, but I work better typing than I do talking. The main point however is that anything I would be willing to talk about, I already am - right here in my straws and forum posts. I can't distill it all down into an hour or a half hour presentation. So, yeah, nah. Not happening.

But if anyone has any questions, just ask, and I'll try to answer, either publicly or via DM. This is already happening, and while I may not reply immediately, I'll get back to people usually within the week.

Cheers!

Completely understand @Bear77

Incredibly grateful for all you do here.

Yeah thanks @Bear77 , you're awesome mate.