History & Geology
Eastern Arizona: Gold and Base Metal Deposits—Part I
February 2011 by W. Dan Hausel
Arizona is well-known for its copper-gold porphyries and massive base metal-gold sulfide deposits such that primary gold deposits in the state are often overshadowed.
The Coolgardie Gold Mining Camp of Southern California
The area was mined intermittently from around 1900 to 1915, but was also mined in the late 1800s, with a total output valued at about $100,000, which is around $9.5 million at the current gold price.
Unique Rare Earth Mine in Texas
Exploration for and prospecting in search of similar deposits should focus on rhyolite bodies located in fluorite-bearing areas.
Eastern Arizona: Gold and Base Metal Deposits Part II
In this review of precious and base metal deposits in Arizona, it is apparent that several significant mines and mineral deposits occur in eastern Arizona, and there is considerable potential for new discoveries.
Enrichment of Mineral Deposits by Weathering—Part II
While both zinc and lead deposits also are enriched by the surface weathering process, in part two we will look at the enrichment process for copper and also gold deposits, and at the interpretation of leached outcrops to figure how rich the concentrated deposits below them may be.
The Goldfield Mining District, Nevada—Part I
An example of some of this extraordinary ore was a lot of about four tons from the Florence mine during the last days of a lease that averaged over 300 ounces of gold per ton.
Sierra County Gold—Part I
...this county contained some of the richest placer ground found in all of California and still produces some pretty impressive finds to this day.
Potholes and Other Bedrock Traps
Potholes in bedrock can trap placer minerals and even be glory holes. They are, at least, interesting geologic phenomena, and at best, a treasure trove of gold nuggets.
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