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.
• "...just about more than I can stand."
• "I hope you can answer my number one question..."
• "...I still go out and mine a little at my old stompin' grounds in Siskiyou County..."
• "...New Prospecting Club in the Southeast."
• "...9 ounces...in two weeks."
• "...It's no secret..."
The faulting, folding and shearing that occurred in the Mother Lode belt has created zones of structurally weak rocks or contacts between different types of rock, which has been favorable for the deposition of gold bearing ores.
From time to time I’ve been doing a series on critical metals and how important they are to our complex and technological society. This month we are going to take a look at copper, and how important that metal is to our modern lives.
When placer miners from the gold rush era began experimenting with the slope of their sluices, they must have pondered the ideal slope for trapping gold in a creek bed too. Logic suggests the same is true for streams...
Climbing up the debris, I pointed my flashlight up a shaft ascending straight up as far as my light would shine. It was the stope of the pay shoot leading to the old tunnel above!
Most gold-bearing veins in this region are controlled by fractures associated with the Melones Fault, a late Cretaceous structure that is 108 to 127 million years old.
I am going to keep to the basics of surface indications and visual clues in the rocks and minerals themselves that help me find gold-bearing veins in this classification of deposits.
The Bawl Mill • Ask The Experts: What is a Spanish needle? • Ask The Experts: Sulfides and fluxes • Legislative and Regulatory Update • The "Madonna Nugget"—A Weekend Hunt to Remember • The Goldfield Mining District, Nevada—Part II • Sunset Sunbaker • A Prospecting Adventure in Mexico • Critical Minerals: Tungsten • Police Urge Author to End Treasure Hunt • Melman on Gold & Silver • Mining Stock Quotes and Mineral & Metal Prices