A very scenic drive from Wanaka to Hokitika. A beautiful environment to be protected.
Our 6 hour drive crosses the Southern Alps mountain range which runs the entire length of the South Island. In layman's terms, there are gold deposits throughout these mountains, which through the erosion process (see below) make their way to the coastline (e.g. Hokitika).
Alluvial gold means gold deposits which have been eroded from the mountains by glaciers, rain and floodwaters. The gold is then naturally deposited by rivers and oceans and accumulated on outwash plains.
A small scale floating screen alluvial gold mine operation inland from Hokitika. Overburden removed, dug down to the natural water table which you can see here. No water is brought in or removed - they use gravity and water directly from the water table to separate the larger tailings from the smaller deposits.
Strict New Zealand environmental regulations require alluvial gold mine operators to restore the landscape back to an 'as is or better' standard - such as productive farmland, forestry or native trees. Above my head there is some new grass already growing which was seeded only months earlier.......
Showing us examples of mine restoration which in this case is being restored as 'hump and hollowed' productive farmland, best suited for this particular farm (this region has many high rainfall events and so flooding is common).
Back at the workshop, to separate the black sand soil from the gold deposits.
A close-up of the good stuff.
Water and gravity in action.
Gold being heavier gets trapped in the mesh as water flows over it.
A continual process of hands-on elimination, removing the black sand from the alluvial gold deposits.
An alluvial gold nugget.
Continuing to separate the black sand from the gold, no chemicals used or needed.
Approx 3-5 ounces of pure West Coast alluvial New Zealand gold.
In summary, alluvial gold mining is the most environmentally friendly form of gold mining available. Unlike hard rock mining, Mother Nature has already done the heavy lifting by naturally separately gold from rock through erosion. It is then a matter of separating the gold particles from the black sand soils - a process achieved so simply through water and gravity.