I have always thought about this. How did our ancestors find salt and metal? Did someone just choose a spot to dig and go at it?
In: Planetary Science
The early ones were probably visible on the surface, you can see traces of gold or copper in the rock and folow the vein into the mountain.
many different ways.
first of all many deposits were simply visible from the surface and people were scavenging for stuff all the time so they would find what ever is there.
Beside this people have also been digging up the ground to build foundations for millennia and we also had quarries for millennia as well.
In these quarries they will inevitably find some other minerals or metals as well as coal deposits and they will also learn about similarities between different areas where they find certain stuff.
we know of mines dating back over 43000 years so its kind of a long tradition.
By using the Mk1 eyeball, knowledge, experience and trial and error.
Take for example ancient Egypt. Egyptian prospectors were highly educated officials of the pharaoh. Expert mapmakers, long apprenticeships with the prospectors that came before them and a lifetime of wandering the Egyptian desert.
They knew which geological features indicated exposed rock, they knew what minerals contained valuable metals&stones (like copper, lead, gold, silver and gems), they knew which other metals and minerals were often found in association with the metals they wanted. Lead often formed alloys with silver, so if you found lead-bearing ores you might find silver-bearing ores by following the vein. If you found quartz there was a decent chance that the vein contained copper and gold as well.
And on top of that. Lots and lots of effort. 19th century prospectors searching the districts where Egyptians had once searched for metals noted that there wasn’t a single vein of Quartz that didn’t bear the mark of earlier and ancient prospecting.
It’s important to remember the state of the world now is not what it was then. The only reason we don’t have metal veins literally sticking up through the ground surface is because we mined all of those easy mines. We basically mined everything that starts half a mile or less under the ground at this point*, but our ancestors didn’t have to contend with that. Most veins were either plainly visible, or left telltale sins for prospectors to spot.
*: Estimate, I have no idea the real number but it’s getting deeper every year for common stuff like copper and iron
In addition to surface deposits, there are vast natural cave systems which, when explored even with primitive lighting, would have shown different veins and strata in the rock face. And, humans being humans, someone dared someone else to lick it and you end up with a salt mine.
What do you mean by “we”?
Latest Answers