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We take for granted the copper of our electrical lines, the iron in our concrete, the rare metals that allowed us to engineer mobile phones that fit in a suit pocket. But all of it starts with finding the ore. True enough, digging up ore is a millennia old activity. It is even how we mark the rise of human industry: Bronze Age, Iron Age… How did it start? Likely with visible ground level outcrops, then dug up.
Needs and inventions took off in the 19th century, and, to sustain it, it generated a frenzy of mining and smelting. That could not be fed by randomly digging. And so, an industry appeared to survey and issue geological maps for mining sites to be established optimally. And, just at the turn of the 20th century, unbelievably rich seams were found in the legendary Congo, as if every known metal had decided to turn up for you: copper, cobalt, lithium, gold, diamond, wolframite …
To find these industrial-grade seams, you need more than a random green stone, a spade and callused hands. How? That is where geological surveys and core sampling comes in. That is what my grandfather did for 30 years throughout Africa.
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There were large scale geological maps roughly sketched by wandering teams at the turn of the century. That is not precise enough to find that seam. You can naturally rely on your flair, using visible geological movements, the way that exposed ground strata looks, but you want certainty.
So, you will systematically sample an area every X meters, digging a hole in the ground. After all, you do not want to miss that diamond mine. This core sampling is done by manual, pneumatic, steam or other rigs. The end has a diamond tipped, for you to extract and study cylindrical core samples, which you will then studiously study and record. The depth can be a few centimetres to 10 kilometres!
My grandfather moved around light, so used tryptic wooden rigs cut on the spot, and manual coring tubes. And how often did he record a coring tip stuck in the bedrock! And when the tube was not stuck, the hole itself was often not closed, and his car would end up on its side as he drove into one.
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There are many other systems, some of which you may be familiar with in pictures, from the Wild West and the Gold Rush, to present-day high pressure water mining. The principle? Well, use nature as it erodes underground seams, or just blast the mine wall with a water jet, and sieve the result. And moon-sized craters be damned. The ore is everything.
But, back to our clever solutions.
Apart from sieves and coring samples, we have today seismic research, to study in your city if the ground is subsiding or not (it strangely seems to never be), electrical research, ground-penetrating radars, etc. Cutting edge technologies to assist us in finding more ore. And yet, when we need rusticity and results, not depending on too much of whizz-bang tech, we use… core sampling. Assisted that is, until we go ourselves to Mars.
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But when I said that you needed more than a spade to dig out core, I was being disingenuous. Because, when your country is Congo, you can very nearly start digging in your garden and find… something. That there is an entire cottage industry of “artisanal” mining, read illegal, in twisty shafts supported by rotten beams, exploiting rather than employing these self-styled miners.
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And when you have 70% of all known cobalt reserves, Greed cannot be too far away: fish from Lake Tshangalele is now full of metals. And regional separatism, ethnic rivalries, growing into rebellions and, lately, wars for this wealth.
Curse or Blessing then?
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