History & Geology
Simple Rules of Gold Geology: Comparing Epithermal and Mesothermal Deposits
July 2017 by Chris Ralph
Geology is a science of general tendencies with frequent exceptions, not one of hard and fast rules that are always true and never vary. For almost every well-accepted rule of gold deposits, I can point you to a number of important exceptions.
Montana’s Rosetta Stone: Discovering Mines In The Treasure State
This is the intelligent way to start modern prospecting. The value of literary research yields challenging outings, specimens, history and geologic research.
Kennecott Copper Mine, Kennecott, Alaska
For approximately 30 years, the mines produced good ore, some so rich it was simply sent straight to bagging, bypassing milling and loaded directly on the rail cars.
The Struggle to Reopen Alaska's Largest Gold Mine
The historical AJ mine, located east of Juneau, Alaska, was considered the largest gold mine in the state at one time. Joe Juneau and Richard Harris struck gold there in 1880, and it has been more recently known as a tourist destination.
The Wild Rush to Find More Cobalt—Part I
While some future cobalt will come from recycling lithium batteries and other products, the coming huge need for cobalt is virtually a perfect storm of heavy demand and insufficient supply.
Las Médulas—The Gem of the Roman Gold Mines
This mine was a real wonder of engineering, and the water supply and drifts had to be carefully managed to keep it in operation. In fact, it didn’t close due to lack of gold, but instead closed with the fall of the Roman Empire.
Prospecting for Pegmatites
…in some cases pegmatites have produced individual mineral crystals that are enormous, attaining lengths of over 40 feet long, and many of the world’s largest mineral crystals are examples that were found within pegmatite deposits.Prospecting for Surface Flood Gold Placers on Low and Intermediate Gradient Streams
Sample panning is a very important method used to find the richest parts of a flood gold deposit before setting up equipment and running material.
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