How Placer Gold is Deposited in Creeks and Rivers
So you’ve armed yourself with all you need to find some placer gold. You have a gold pan, shovel, pick, snuffer bottle, and a little jar to carry your gold nuggets in. You’ve traveled to a famous gold bearing stream, and through careful research, you have total confidence that there is gold there to be found.
Walking down to the edge of the water, you spy a nice beach along the edge of the water and scoop some sand and gravels into your gold pan. Panning slowly and carefully, soon your left with just a pinch of small gravels, maybe some black sands, and….. no gold?
No doubt, this has happened to many beginning prospectors, who make the mistake of thinking that a gold bearing river has gold scattered throughout. All that is needed is a miner with his gold pan to come and gather it all up. Of course, gold is not evenly distributed throughout a river system, so it is important to understand some basic facts about gold.
Gold is heavy. Gold has a higher specific gravity than the sands and gravels in the stream, and that makes it somewhat predictable. You need to go down to find it; down below the sands and gravels, and down deep into the cracks and crevices in bedrock.
During a high water event, the material in a stream acts in the same way that it does in your gold pan. Everything is being agitated, and the heavier gold is able to travel downward until it hits a major obstruction.
Beginning prospectors commonly make the mistake of not dig deep enough to get to the gold. It may be right below their feet, but it is often covered by significant overburden that contains little or no gold.
Placer gold deposits on bedrock:
Not only does gold go deep down in the gravel, it is also constantly moving downstream. It may get caught in a deep bedrock crack, but before it settles down to bedrock it has a good chance of moving a significant distance down the stream during a high velocity stream flow.
Once again, it’s weight will cause it to settle in certain predictable areas, places that the stream slows down or loses the energy needed to move the gold any farther. These areas include deep pools beneath waterfalls, behind large rocks and boulders, amongst exposed tree roots, and the inside bends of a stream.
A good way to spot areas like this is to identify places that fish are congregated, slack water near the faster current. These are the same general areas that gold will be able to lose momentum. Once it finds a location that it will stay put, it will move down into the gravel until it reaches bedrock.
An aerial view of typical placer gold deposition:
When prospecting for gold, always be on the lookout for black sands. Black sands are composed of various iron oxides, and are commonly associated with placer gold due to their high specific gravity. These black sands will settle out a stream the same way that the gold will, so always be on the lookout for high concentrations of it.
The presence of black sands do not necessarily guarantee the presence of gold, but if you are in a gold bearing stream there is a good chance that gold is nearby. If your gold panning is resulting in black sands, mercury, and lead bullets or fishing weight, you are on the right track.
Keep at it and find that gold!