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.

The Verde Copper-Gold-Silver-Zinc District, Jerome, Arizona

October 2012
When I was a student in the College of Mines at the University of Utah, the Verde district was used as an exploration model for “submarine volcanogenic massive sulfide deposits.” So I looked forward to visiting this district and the town of Jerome in central Arizona in the spring of 2012.

Critical Metals: Lithium

February 2014
Prospecting for lithium deposits can take a number of different directions, because this metal can be extracted from a variety of geologically differnet sources.

The Strange History of the Utica Mine

January 2016
In the summer of 1854, John Selkirk, a discouraged placer miner who was down on his luck and ready to go back to Massachusetts, tied his mule up in a gulch north of what is now downtown Angel's Camp.

Picks & Pans: Gold Recovery in Placer Mining Operations

August 1999
Two of the major factors affecting the profitability of a placer mining enterprise are the relative efficiency of the mining equipment, and the rate and percentage of recovery obtained while conducting mining operations.

The Wild Rush To Find More Cobalt—Part II

March 2018

In this second part on cobalt, I will take a look at the various types of cobalt deposits and how you can prospect for them. Who knows—perhaps the next big cobalt strike will be yours.

Know Your District

December 2010
We have to remember that the earliest miners were not geologists, but came from a variety of backgrounds. Their survival depended on finding enough gold so they worked hard and adapted to whatever challenges these new areas presented.

Las Médulas—The Gem of the Roman Gold Mines

July 2018

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.

Subscription Required:
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

Free:
MMAC Update