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.

Green Valley Gold District, Payson, Arizona

March 2016

Most gold-bearing quartz veins found in the district were fracture fillings in faults enclosed by crushed quartz zones along their margins. Since the host rocks were often extensively weathered, portions of the veins stood out as positive, resistant outcrops. The gold-bearing veins ranged from a few inches wide to the vein at the Gowan mine that was as much as 12 feet wide. 

One Question, Forever Unanswered—Did He Really Find the Gold?

May 2011
This was one of those stories where you have no doubt that the person telling it believes it to be true. But was it?

Using Vegetation and Soil Conditions as Prospecting Aids

January 2013
Wouldn’t it be great if you could know if there is gold in the ground without setting foot on the ground? Well you can, to a certain extent, if you can recognize mined ground from unmined.

Copper Deposits of Alaska

February 2014
Only the famous Kennecott copper mine was able to continue operating through the Depression owing to the exceptional richness of its ore.

Gold, Quartz & Chalcedony—Part II

November 2011
The specific gravity of chalcedony is 2.58 to 2.64. This is slightly lower than coarsely crystalline quartz because of slight porosity in chalcedony. Being so light, it will easily wash out of a gold pan.

Silver and Base Metal Deposits of the Pioche District

June 2014
The areas that were mineralized with the bedded ore were huge and vast tonnages were indicated, although they had no idea at the time.

Sierra County Gold—Part II

January 2014
...we will continue our examination of the rich streams and mining districts, and then take a look at some of the big nuggets that have been found here.

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