& The Art Of Thinking On Your Feet

Eleven out of ten mining and exploration professionals, particularly geostatisticians, agree that the science of sampling is crucial to the discovery process. I’d suggest that everything we do as minerals’ industry geologists can be focused down into that single activity: sampling.

Every dollar we spend on logistics, geophysics, drilling, mapping and beer is spent to collect samples. It’s the ONLY way to check that there’s metal in the fascinating rocks you’ve described in your monthly reports. Geophysics won’t tell you, regardless of what those shifty geophysicists say. Satellites can’t tell you from 300km up, and mapping definitely won’t tell you.

Geologists. We Smash Things.

Minerals geologists take a lot of samples: drill core, percussion drill chips, grab samples, chip-channel samples, saw cut channels, Stream Sediment, run-of-mine ore samples, base of till, soil etc. (Eventually, if you work in remote locations, you’ll also end up collecting a different type of sample in a small plastic pot, but I’ll save that for a future post.)

Ultimately, the process of sampling still comes down to brute force using hammers, drills, shovels, diggers or explosives. Yes, geology combines the empirical beauty of observation with the subtlety of multi-disciplinary science, and then we smash things.

Whatever they’re called, all samples look the same: a greyish plastic bag, chunks of muddy grey-brown shit or pebbles, sealed with a zip tie, with a cryptic sample number that’s the source of all error when the data base crashes.

It’s Voodoo & Promotion

What do we do with the assays once we get them? The in-house geochemist runs his QA/QC voodoo on the data, then he sends around the final assay results. The CEO takes the numbers, adjusts the values upwards (it’s called rounding), misinterprets them and writes a glowing news release to investors and everyone’s temporarily happy.

But cynicism aside for a second, my broader point is that success in exploration largely derives from the samples lovingly collected by the project geologists. No sampling, no project.

I Bleg, You Bleg, We All Bleg Together

Now, imagine that you’re a young geologist and you’ve spent weeks conducting a regional prospecting and stream sediment sampling program, collecting hundreds of samples, only to lose the lot: all that effort and expense, for nothing.

It happened in the early-1990s to a Turkish colleague of mine (who I’ll call Mehmet) who was wrapping up a BLEG (Bulk Leach Extractable Gold ) stream sediment program in Bulgaria. BLEG samples are multi-kilogram stream sediment samples that take a long time to collect. You may only get 2 or 3 per day depending on access, and the analyses are expensive, but it’s a remarkably good technique for screening large areas for gold.

We were looking for gold and copper deposits in the south of the country. There were no properly accredited assay labs in Bulgaria, so all samples went east across the border into Turkey for analysis at a lab in Ankara.

Mehmet crossed the border near Svilengrad in southeastern Bulgaria. He was promptly stopped by Turkish customs who wanted to know what was in the bags in the back of the truck. It was then that he committed the cardinal sin and told the truth; he was prospecting for gold on behalf of a foreign mining company, and the samples were to be analyzed for gold in Ankara.

Stop That Man!

The word gold set off the alarm bells, and the building went into lock down (this may be exaggeration on my part.) Customs convinced themselves that Mehmet was trying to smuggle commercial quantities of gold for resale in Turkey, hidden in bags of sand and gravel.

The truck, with its vital load of samples, was impounded and an entire field season of work was suddenly in jeopardy. Mehmet was told he’d have to drive the truck to Ankara with a customs officer, and deliver the load to a bonded warehouse where customs would check for gold.

It’s nearly 450km to Ankara from Istanbul, with some windy roads and bad Turkish driving to contend with. Mehmet is a very charming man in a disarmingly hospitable Turkish way; give him enough time and he can make friends with anyone. The customs officer had no idea what hit him.

By the time they reached Ankara they were best friends, and the officer agreed that there was no need to deliver the samples to the warehouse that night. Instead, Mehmet invited him out for a very boozy dinner at a favourite restaurant. No expense was spared on the food or drink although most of Mehmet’s rakı ended up in the plant pot.

Ouch. My Head Hurts.

After helping the officer back to his hotel room, where he immediately passed out, Mehmet jumped in the truck and picked up his wife. They grabbed hundreds of sample bags, tags and ties and drove out of town to a nearby lake with a gravel beach. It’s a beautiful spot where Turkish families gather to picnic and enjoy a break from the grey of Ankara.

Under the romantic white light of the Anatolian moon they worked all night, transferring the original samples to a new set of bags. The old bags were refilled with barren lake gravel and stuck back in the truck. Mehmet’s wife took the re-bagged originals home and then to the assay lab. The next day, a very hungover officer accompanied Mehmet in the truck to the bonded warehouse where the decoy samples were impounded. As far as we know, they’re still there, tucked away in a dusty corner, lonely, unloved and definitely not gold-bearing.

The program was saved by some quick thinking, some carefully applied booze, a shovel and a nice lake.

Mehmet now runs a gold mine for a mid-tier producer.

Don’t Forget

If this piece hasn’t put you off my blog for life or induced narcolepsy, you really should subscribe to urbancrows.com via the horrible subscription box that I placed near the top of the page. I’m currently at 79 subscribers and heading sedately towards… ooh…maybe 80-ish by the end of the summer. I’ll be sure to email you more drudgery from time to time.

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