WHERE DID THE GOLD COME FROM? | PLACER MINING

Gold is a yellow metal that is used to make jewelry, coins, art, and more. When the word “gold” is mentioned, many things come to mind: gold medals, Egyptian tombs of gold, pirates with gold coins, or gold bars in bank vaults. It has become a symbol of wealth, beauty, and power. Gold is incredibly valuable and that is why, when large amounts of it were found in Yukon, people all over North America rushed there to mine some for themselves. Just a little bit of gold was enough to make a person rich beyond their wildest dreams.

Where Did the Gold Come From?

Scientists believe that all of the natural gold on Earth came from outer space. Gold takes a massive amount of energy to make, and because of this, it can’t be created in a lab. It can only be formed in space when really big stars explode (this is known as a “supernova”). Billions of years ago, when the Earth was still a young planet, it was hit by asteroids that were filled with gold. These asteroids deposited their gold in the rocks on Earth’s surface.

A large amount of gold was deposited in the area that would eventually become known as the Klondike in Yukon, Canada. (This original large deposit of gold is often called the "mother lode.") As the rocks that held the gold were eroded by water and glaciation, it was washed downhill to nearby creeks. Over time the gold was buried underneath layers of sand and mud, where it lay until it was discovered by prospectors thousands of years later.

The first major discovery of gold in Yukon took place at Rabbit Creek, later renamed Bonanza Creek. That gold was found on the shallow creek bottom, but most other gold deposits were much farther below the surface—sometimes up to twenty feet deep, far beneath the running water of the creek! 

Miners had to dig down through the muck, then haul buckets of dirt back to the surface and sort through it to see if there was any gold. To make things more complicated, the dirt was usually frozen in a layer of permafrost (permanently frozen ground, often starting several metres underground). The permafrost had to be thawed, either by the sun, steam, or fire, before the dirt could be examined for gold.

Finding gold in the Klondike was a matter of chance and being in the right place at the right time. There was no way to tell for sure where the gold would be. The only thing to do was pick a spot and start digging. There wasn’t as much gold in the Klondike as there had been in earlier gold rushes, like the California Gold Rush, but this gold was concentrated in a much smaller area. Miners had better odds of finding large amounts of gold in the Klondike. Once it was found, in the form of dust, grains, or (if you were lucky), larger gold nuggets, it could be taken right to the bank.

Some lucky miners found $500,000 (in 1869 dollars) in gold from a single spot. That’s the same as over $15 million today!

Placer Mining

There are four main types of mining:

1. Surface mining

2. Underground mining

3. In-situ mining

4. Placer mining

The first two involve digging or drilling into the ground to get at mineral deposits hidden beneath the surface of the Earth. In-situ mining, on the other hand, is the process of injecting chemicals into the Earth to dissolve a specific mineral, which is then pumped out. These are all examples of hard rock mining, where minerals are taken out of hard rocks. 

The last type of mining is where mineral deposits are separated from the loose dirt and mud in a river. This is called placer mining and it was this technique that was used during the Klondike Gold Rush.

One benefit of placer mining is that it doesn’t require a lot of expensive equipment, just a few simple tools like a gold pan or a sluice box, which are used to separate gold from the mud and gravel in a stream. A sluice box is a long narrow box that is placed at an incline in a shallow part of a stream. Dirt is scooped into the box and then carried through it by water from the stream. As the dirt passes through, heavy materials like gold and rocks are separated out and trapped at the bottom of the box.

During the Klondike Gold Rush, sluice boxes were much more efficient than pans, but they needed a good supply of water to properly work. The creeks had to thaw in the spring before the sluice boxes could be used. For this reason, most of the actual digging was done in the winter. The ground was thawed with fire, then dirt was dug up and dumped in a huge pile that would be “sluiced” (washed through the sluice boxes) in the summer. 

Miners had to wait months to find out if their hard work during the winter would pay off. Was all that time they’d spent in the dark, cold mining shafts underground worth it? There was always a huge amount of suspense for this part, because sometimes entire fortunes of gold could be hidden in those dirt piles.