(California's gold-bearing Yuba River in high flood.)
You should never underestimate the impact that stream or dry placer flash flooding can have on nugget movement and deposition. Therein lies the heart of this particular post.
Flooding or flash flooding occurrences in gold-bearing districts or locations are one of the most important factors in gold movement and deposition physics, nuggets included. The stronger and more sustained the flood or flash flood, the greater the chance that the location and distribution of nuggets will be altered in one of the following ways:
- Nuggets will be washed closer to the surface or completely exposed.
- They'll end up mixed within intermediate gravels.
- Nugget "pockets" may be formed.
- Coarse gold and nuggets may be deposited into benches or gravel bars.
- Heavier pieces of gold may be forced down onto bedrock or into bedrock cracks and crevices.
- Nuggets under or behind large stream or wash obstructions may increase in quantity or be washed away entirely.
- Shallow bedrock nuggets may be "scoured" away and carried to new location.
Moving Those Nuggets
In terms of gold and placer nugget deposition flooding or flash flooding is a two-edged sword... sometimes it can help you in your search for nuggets and coarser gold, and sometimes just the opposite occurs. Generally however, flooding and flash flooding are beneficial and should be exploited in a timely fashion for maximum effect by small-scale gold prospectors and miners anywhere placer gold exists.
Remember, water (and its movement and force) is the single most important factor in gold deposition and recovery. Even in the driest of regions where desert gold placers are the predominant mining venue, seasonal thunderstorms and their brief, heavy downpours can move more gold in a matter of seconds than you and I could in multiple lifetimes. I've personally witnessed the power of flash flooding on desert placers numerous times and it's a jaw dropper. Ditto for some of the flooding I've witnessed in Northern California's Motherlode gold region.
(A nice little nugget in hand.)
Just so you know, in this latter location savvy miners and gold prospectors don't waste a minute getting to their claims or working locations once water levels drop and calm. In fact, if you're there when Motherlode flooding ends, it's almost like a mining "feeding frenzy" as the locals scramble to get their share of the new gold that's been washed into (or exposed at) their favorite location. Many a good-sized nugget has been won this way, so take note. I never drop a tip like this just for the hell of it...
I wish you well and the greatest success in your nugget-hunting endeavors.
(c) Jim Rocha (J.R.) 2014
Questions? E-mail me at firstname.lastname@example.org