When any river or waterway cuts a new channel, the gold held in the old gravel gets "re-washed" back into the main flow. This is one way gold that has been ground from nuggets or out of veins gets flushed onto/into sand and gravel banks. The now lighter ground gold flakes are light enough to be picked up by the current and carried up onto the banks during high water flow rates.
Nuggets on the other hand are focused and channelled to the deepest point on bedrock in a river, however, exceptions do occur. When gold encounters fractured bedrock or cracks and crevices it will stick in those spots. The current isn’t strong enough to wash this course gold out of these dips and pockets.
HOW TO WORK SMOOTH AND BROKEN BEDROCK
Mother Nature is medium of extremes. You can come across huge section of flat, smooth, rolling bedrock in valleys and river bottoms
that go for miles with only the odd fault line or wrinkle.
Then you will start mining another area that is full of broken, fractured bedrock that is full of dips and holes. What type of bedrock do I prefer? Actually both and I use different techniques when I work smooth or broken bedrock.
How far does gold travel on bedrock? Well on smooth bedrock it will travel for miles accumulating in low spots and any change in height (natural steps). Extracting some good quantities of gold from smooth rock is quite easy. You follow the ups and downs of the rock as it travels along the river channel and take full advantage of the low locations that occur naturally along its length. The disadvantage? You travel along the bedrock looking for low spots that occur naturally. These low spots will pay big as they contain the sum of the rivers gold wealth all concentrated into one happy location. The main disadvantage is the depth you have to dig (sometimes quite a way down) to mine out these honey holes, but, if the river contains any amount of gold, the low locations will be the spots to dig out.
Of course any location that has a reasonable change in height will offer some rich rewards. I mentioned natural steps that can happen on bedrock. No matter what direction these steps occur, they will hold concentrations of gold. In fact, I have dug out spots out of steps in bedrock that contain 2 – 3 fair sized nuggets and these nuggets will trap smaller pieces behind them. The larger nuggets sit in front of the step and immediately behind the will be an accumulation of pin and pencil lead head sized “micro nuggets” that trail off like a short comet trail. This depends on the depth of step and the direction it faces, but either way any change in height offers some good gold with smooth bedrock.
BROKEN OR FRACTURED BEDROCK
You hate it and you love it… I am talking about fractured bedrock. On the one hand I like broken, irregular bedrock because it traps and hold gold of all sizes.
The down side is getting it out of its rocky prison, especially if it is over 8” down inside the rock. This will typically happen with bedrock cracks. One of my favorite tricks is to go to a well know “gold area” where there is a lot of cracked, broken bedrock and recover what other miners couldn’t reach. I am not trying to be smug it is just there is very little debris left in these cracks and a lot of compacted gold (flake and micro nugget) at the bottom. I have watched other miners spend hours digging in these cracks with long flattened wires, bent spoons, dentist tools and a host of other pick type tools.
What I use is a bedrock suction pump called a “Gold Recovery Pump” with a thin tube nozzle and a stainless pick probe built onto the other end. I use the angled probe end to loosen the compacted gold and suck it up with the hand suction pump. My Gold Recovery Pump has a 3” suction chamber and will work wet or dry, however if I hit a deep crack with some rich stubborn gold at the bottom I will take a large plastic milk container full of water and fill the crack to approximately 1” above the stuck gold. Then I will use my pump to work the crack in a vertical motion. I use this step motion (up and down) to loosen the gold and suck it up as I step along. The water in the crack extends the reach of my Bedrock Suction Wand and creates a much higher “withdrawal rate” of the stuck gold.
A few of the other miners have gotten mad at me, mainly because I can recover a lot of inaccessible gold in just a few minutes where as they have spent a day fishing out small amounts with their wire picks.
Really there is only three ways to get at this gold.
1) Use wire pick probes and fish out each flake or micro nugget of gold piece by piece.
2) Use a large suction pump with a thin tube to reach the stuck gold.
3) Use heavy equipment to tear up all the bedrock to a depth that is just greater than the deepest rock.
SOME FACTS ABOUT FRACTURED BEDROCK
- The largest nuggets will be in the first bedrock crack in the most upstream spot.
- Cracks that are angled slightly backwards will tend to accumulate the most flake gold.
- When you have a choice, hit broken or fractured bedrock at the lowest water level. Cracks nearest the rivers center will always have the heaviest, largest accumulation of gold.
- Earthquakes and seasonal temperature differences can open and close bedrock cracks as our earth’s crust moves. There are quite a few factors to consider as to how often and how much this happens. Local landslides can be an indicator of this (ground movement).
- Old bedrock will be the most broken as well as the weakest.