Geology and stories from the past
The Bawl Mill
March 2016
• Do as I say, not as I do...
• By the numbers...
• Do as I say, not as I do...
• By the numbers...
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.
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. Nevada's Silver City Gold District—Part I
March 2016
The name Silver City is quite ironic as it doesn’t really fit the area’s metal production. The area encompassing the Silver City district is a great, stand-alone gold district, where the production value of gold has been much more than that of silver. Since the initial discovery of gold-bearing veins in the mid-1850s, the area has been a center of continuous small and large-scale gold production.
The name Silver City is quite ironic as it doesn’t really fit the area’s metal production. The area encompassing the Silver City district is a great, stand-alone gold district, where the production value of gold has been much more than that of silver. Since the initial discovery of gold-bearing veins in the mid-1850s, the area has been a center of continuous small and large-scale gold production.
Enrichment of Mineral Deposits by Weathering—Part I
March 2016
The exact minerals formed in the concentrated supergene deposits depends much on the type of country rock around the deposit and the chemistry of the deposit itself, but if conditions are right, this process will form some rich patches of bonanza ore, in some places valued at thousands of dollars to the ton.
The exact minerals formed in the concentrated supergene deposits depends much on the type of country rock around the deposit and the chemistry of the deposit itself, but if conditions are right, this process will form some rich patches of bonanza ore, in some places valued at thousands of dollars to the ton.Alaska: Kodiak Islands Mineral Resources
March 2016
The fresh material is worked and concentrated by the waves on the flat, wide beach platform. The waves wash away the lighter minerals, leaving the heavies near the bluffs and in depressions on the beach.
The fresh material is worked and concentrated by the waves on the flat, wide beach platform. The waves wash away the lighter minerals, leaving the heavies near the bluffs and in depressions on the beach.Gold in Quartz
February 2016
Because quartz and gold may be deposited together across a considerable range of temperatures, not all quartz veins are the same, and there are several different types of gold-quartz deposits.
Because quartz and gold may be deposited together across a considerable range of temperatures, not all quartz veins are the same, and there are several different types of gold-quartz deposits.
Northwestern Alaska Mineral Resources
February 2016
Gold and jade are actually only minor mineral resources for the Northwestern Alaska region as a whole. Modern prospecting has focused more on base metal than precious metal resources.
Gold and jade are actually only minor mineral resources for the Northwestern Alaska region as a whole. Modern prospecting has focused more on base metal than precious metal resources.
Electrum: Gold and Silver Together
January 2016
...if you are out prospecting and find something that looks very much like a nugget but has an odd greenish-gray cast to it, don’t be too quick to simply toss it aside as junk.
...if you are out prospecting and find something that looks very much like a nugget but has an odd greenish-gray cast to it, don’t be too quick to simply toss it aside as junk.
Mineralized Faults and Contacts in the Search for Gold
January 2016
Fault zones and rock contacts are important because the vast majority of gold and silver deposits, as well as those of many other metals, are formed by hot, mineralized water solutions.
Fault zones and rock contacts are important because the vast majority of gold and silver deposits, as well as those of many other metals, are formed by hot, mineralized water solutions.
The Significance of Nuggets in Placers
January 2016
Chances are better that both types of gold did not come from the same source. Let's look at the probable conditions to cause two types of gold in a placer.
Chances are better that both types of gold did not come from the same source. Let's look at the probable conditions to cause two types of gold in a placer.
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.
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.
Researching Mineralized Areas
December 2015
There are a load of ways to do research, and I’m going to talk about how I do it—maybe you’ll get some ideas that will work for you, too.
There are a load of ways to do research, and I’m going to talk about how I do it—maybe you’ll get some ideas that will work for you, too.
All About Minerals
November 2015
There are several common ways that new mineral crystals form and grow. Perhaps the simplest is when minerals form through the cooling of molten rock and the atoms bond together into mineral crystals.
There are several common ways that new mineral crystals form and grow. Perhaps the simplest is when minerals form through the cooling of molten rock and the atoms bond together into mineral crystals.
Associated Gold Placers of the Comstock
November 2015
What many people don’t realize is that the Comstock Lode produced over 8,000,000 ounces of gold…
What many people don’t realize is that the Comstock Lode produced over 8,000,000 ounces of gold…
Gold in Tertiary Gravels
November 2015
In some places, semi-continuous sections of riverbed can easily be linked in many places to identify the path of the ancient rivers.
In some places, semi-continuous sections of riverbed can easily be linked in many places to identify the path of the ancient rivers.
Rock and Formations of the Mother Lode Gold Belt
October 2015
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.
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.
Iron Ores and Iron Mining
September 2015
For more than 40 years, iron ore prices have been decided by private negotiations conducted between the largest of the iron miners and the largest steel producers. These two sides dominate both the spot and contract iron ore markets.
For more than 40 years, iron ore prices have been decided by private negotiations conducted between the largest of the iron miners and the largest steel producers. These two sides dominate both the spot and contract iron ore markets.
Prospecting for Silver Deposits
August 2015
In some ways, silver is the forgotten precious metal because it straddles both the world of precious metals and jewelry, while having many important industrial applications like a base metal. The price of silver reflects both the precious metal investment demand as well as the industrial demand.
In some ways, silver is the forgotten precious metal because it straddles both the world of precious metals and jewelry, while having many important industrial applications like a base metal. The price of silver reflects both the precious metal investment demand as well as the industrial demand.
Gold and Rare Earth Elements in New Mexico
August 2015
We import nearly all of our REEs from China, so it’s critical that we find and continue to develop domestic resources of these elements.
We import nearly all of our REEs from China, so it’s critical that we find and continue to develop domestic resources of these elements.
Ask The Experts
July 2015
Q: Is there a correlation between fault zones and mineralization of economic metals?
Q: Is there a correlation between fault zones and mineralization of economic metals?
