'Gold Rush, White Water' Season 3: Panning process for recovering gold and placer deposits where nuggets accumulate, explained
The Discovery Channel’s documentary series ‘Gold Rush: White Water’ that has entered its third season follows a father-son duo weathering the harsh Alaskan terrain in search of gold. In the U.S., the tradition of “panning”, a form of placer mining that extracts gold from a placer deposit using a pan, is rich.
From the California and Klondike gold rush in the 19th century to the present day, panning is still popular as is evident from the enthusiasm of ‘Dakota’ Fred Hurt and Dustin Hurt. So, how does panning work?
Panning is the simple method of separating particles of greater specific gravity from soil or gravel by washing in a pan with water. Panning is one of the principal techniques of the individual prospector for recovering gold and diamonds in placer deposits.
A placer deposit is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. Gold deposits, or lodes, are found in veins of fractured rock.
After millions of years of weathering, gold nuggets and flakes are eroded out of the veins and carried away by streams and rivers. Gold, being 19 times heavier than water, tends to settle on the bottom and in the bends of rivers, streams, and lakes with sand and gravel.
What miners do is they scoop up sand, gravel and rock from the river or creek bed. They mix it with generous amounts of water. The gold, because of its greater density, sinks faster than the other materials and collects at the bottom.
Of course, long gone are the days when this was done by hand alone. Today, prospectors use high-pressure water, excavators and dredgers to sift through the minerals to find the yellow metal.
Of course, not every river has placer deposits or even gold deposits that are visible to the naked eye. So, how does one identify where to look for gold? According to Ron Wendt, a gold prospector, it is something that comes with a certain amount of experience.
He said, “When prospecting, you do not have to become an expert in rock identification, but it does help to become aware of the essential types of rocks and bedrock that you will encounter in the field. Learning to read these rocks and layers can greatly enhance your ability to find gold.”
In the United States, streams and rivers in the West and in Alaska have been known to have gold deposits -- that explains why Fred and Dustin are there. However, according to the U.S. Geological Survey, most placer deposits in Western river beds have either been depleted by prospectors or greatly exaggerated.
Wherever undiscovered placer deposits exist today, they will likely be low-grade gold and inefficient to develop commercially. There are other ways to identify a gold reserve. And not just in water beds.
Ravi Anand, of the Commonwealth Scientific and Industrial Research Organisation (CSIRO), along with his colleagues gathered hundreds of samples of sediments, soil and acacia leaves, to figure out if the trees tell us where to go. Anand and his colleagues found gold is preferentially absorbed by living material. This suggests that digging deep under gold-rich trees and mounds could lead to veins of gold.
‘Gold Rush: White Water’ airs on The Discovery Channel every Sunday at 10 p.m. ET.