1What is the one rule for where gold settles?
Gold drops out where the water slows down. Every specific trap — bend, bar, boulder, junction, bedrock crack — is just a place where the current loses speed and can no longer carry a heavy grain.
The physics of slowing water, and the places in a stream where heavy grains stop.
Gold drops out where the water slows down. Every specific trap — bend, bar, boulder, junction, bedrock crack — is just a place where the current loses speed and can no longer carry a heavy grain.
On a bend the water on the outside runs fastest and erodes; the inside runs slowest and deposits. Heavy gold drops on the inside bar, particularly at its upstream end where the slowing begins.
The upstream head of the bar, down to bedrock or the hardest layer you can reach. Gold tends to sit at the top end of the bar and on the bedrock beneath it, not in the loose sand at the tail.
A slope break is where a steep stretch of stream suddenly flattens. Water that was fast enough to carry gold slows the moment the gradient drops, and gold settles in the first pool or gravel bar below the break.
Where a tributary joins, two flows collide and slow each other, and the combined bed widens. The pool and the bar just below a junction — on the side the smaller stream enters — are classic traps, especially if the tributary drains mineralised ground.
It stops it. Gold sinks through loose gravel until it meets bedrock, then lodges in cracks, behind ledges and in potholes. Where bedrock crosses the stream, especially at an angle to the flow, the cracks act like the riffles of a sluice.
Cracks running across the current, or angled against it, catch far more than cracks running with the flow. Water passing over a crack that faces upstream drops gold into it; a crack parallel to the flow just lets the gold slide by.
Yes. The downstream side of a large boulder has a pocket of slow water where gold settles, and the gravel packed under and around the upstream face can be rich too. Big, stable boulders that have sat through many floods are best.
The plunge pool is turbulent, and gold gets churned rather than settled — but the first calm gravel bar downstream of the pool and the bedrock cracks at the pool’s edge can hold it. Sample the pool tail, not the churning centre.
The shallow, slowing stretch at the downstream end of a pool where the bed rises toward the next riffle. The current slackens over the tail and drops what it carried through the pool. Pool tails on bedrock are excellent.
Rarely. The fastest water carries gold rather than dropping it. Look at the edges: the inside of bends, the eddies behind obstacles, the lee of bars. The exception is where bedrock is exposed mid-channel with cracks across the flow.
Old stream gravel left high on the valley side when the stream cut down to a lower level. Benches are the beds of the same stream from long ago and can hold gold that today’s channel never touched. Look for flat terraces with rounded gravel above the current bed.
Normal flow is too weak to move gold at all. Only floods move the whole bed, and when the flood ebbs gold settles first, at the spots where the flood current slowed. That is why the flood-line traps matter more than the low-water channel.
Along the path the flood took, which is often wider and straighter than the summer stream. A bar that sits out of today’s water may have been the inside of the flood channel — sample it as if the water were still there.
No. It concentrates in narrow streaks and pockets and is nearly absent between them. Two pans a metre apart can differ enormously. This is why systematic sampling beats digging one large hole.
A small trap — a bedrock pothole, a crack, the base of a boulder — where an unusual amount of gold has accumulated. Pockets are the reward for reading the bed carefully; they are found, not predicted.
Closest to the source and deepest in the bed: on bedrock, under the biggest boulders, at the head of bars. Coarse gold barely moves, so it stays near where it entered the stream.
Further downstream and higher in the deposit, in the slower, sandier parts of bars and on the surface after a flood. Fine gold behaves partly like sand, so it travels with the sand and settles with it.
A narrowing forces the flood through a small gap, which speeds the water up — and just below the gap the valley opens and the water slows sharply. The first bars and bedrock below a constriction are prime traps.
The current dies and everything drops, sand and gold together. Gold gets buried under a lot of sand, so these spots are rich in theory but hard to work by hand. The last stretch of gradient before the flat is more practical.
Their upstream heads can, especially on bedrock. Mid-channel bars form where the flow splits and slows; gold drops at the head, where the slowing begins, and rarely at the sandy tail.
Upstream. The head of the bar is where the current first slowed enough to drop heavy grains. The tail collects the lightest material. Dig at the head, down to the hardest layer.
As deep as it can go: on bedrock, or on the first hard layer that stops it. Surface gravel holds only what the last flood dropped. If you can reach bedrock, clean it — the cracks are where the bed’s history is stored.
Scraping and brushing the exposed bedrock and its cracks after removing the gravel above, then panning every scrap. A stiff brush, a crevicing tool and patience recover gold that a shovel would leave behind.
Moss on rocks in the flood zone acts like a natural mat and catches fine gold; roots along undercut banks can hold flakes. Both are small-scale and worth a pan when they sit at a known trap.
Streams wander. A dry channel across a meadow or a gravel terrace on the slope was the active stream once and trapped gold by the same rules. Old channels are often unworked because they are not obvious.
Often. Old workings prove the source and usually left fine gold, deep gravel and bedrock cracks unworked. Sampling around tailings and just downstream of them is a reasonable approach.
The best single trap: a bend right where the gradient flattens. Water slows for two reasons at once, and the inside bar below the break can be many times richer than either feature alone.
The tributary carries its own load and pushes it into the main stream, where the combined flow slows. The bar that forms on the tributary’s side of the junction gets that load first. If the tributary drains mineralised ground, that bar is where its gold lands.
Most of it. Gradient, bends, junctions and constrictions are visible in elevation data, which is exactly what GOLDONGO scores. What a map cannot show is bedrock cracks, boulders and the current state of the gravel — that part is done on foot.
GOLDONGO scores entire stream networks for the trap geometry this guide describes — slope breaks, inside bends, junctions and bedrock. Pick your region and see where it stands.
This guide is general education, not advice for a specific place. A score, a map or a sentence here is not a licence to dig: the rules for prospecting, land access and protected areas differ from place to place — learn the ones that apply where you are before you go.