Gold Rush Mining Lexicon Gold Rush Alaska
If you're a rookie gold miner like most of the Gold Rush crew, there are lots of specialized terms and equipment that make up the core knowledge set for understanding the processes and challenges of gold mining. Here are the basics that have been covered in the show — the essentials that all gold buffs need to know:
PLACER GOLD MINING:
This mining method involves searching for gold in ancient layers of sediment, known as alluvial deposits. These layers are composed of tiny bits of gravel, sand and minerals eroded from hard rock by moving water long ago. Alluvial deposits are found in virtually every area where gold is found in hard rock, or lode, deposits. They may be in rivers and streams, but they also can be found thousands of feet from the nearest body of water. In the United States, placer mining began in the Appalachian region in the late 1700s, but it was the discovery of a placer deposit along the American River in 1848 that triggered the California Gold Rush and the explosive growth of placer mining. Up to the present day, roughly two-thirds of the gold discovered in California has come from placer deposits.
Placer mining is very different from mining gold deposits embedded in hard rock, which requires miners to use explosives and crush rocks to extract gold. Instead of brute force, placer miners rely upon gravity, water flow, vibration and magnetism to separate gold nuggets and fine dust from the alluvial material. While placer mining conjures up up images of grizzled prospectors panning in streams, modern larger-scale placer mining operations use complex equipment to separate gold from the detritus. Some placer mining operations even use dredges to churn though huge quantities of alluvial material.
Alluvial material consists of larger pieces of gravel and smaller, finer particles. The finer material usually contains the gold, which is why it's called "pay dirt." Gold miners first separate the pay dirt from the gravel, and then sift more carefully through the pay dirt to extract the gold.
Watch Video: Pay Streaks and Glory Holes - Picking a place to start digging for gold means finding out where old river beds have left behind now buried pay streaks.
This is a more general excavation and mining term, rather than one exclusive to gold mining. A glory hole is a big, impressive-looking excavation that's open to the surface. It can be either the top end of a deep mine shaft, or an open-pit mine. Sometimes a mining process called block caving, in which ore is removed from a tunnel, causes the underground excavation to collapse, forming a glory hole. In typical alluvial gold mining, it can also refers to the eroded out depression formed at the base of an ancient waterfall. Because this concave geometry is known to be ideal for gold concentration, these glory holes are much sought after deposits.