The Rochester Mining District of Nevada

August 2017 by Chris Ralph

Only the richest ores could be worked and shipped off for processing at a profit. As a result, early mining in the southern part of the Humboldt Range was short-lived. In the 1880s, placers were discovered in Spring Valley and American Valley on the east side of the range...

Potholes and Other Bedrock Traps

September 2012
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.

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.

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.

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.

Gold Depositiion and Gradients of Placer Streams—Part II

July 2012
The steeper the gradient is, the more potential erosive power to move gold and other bedload sediments, and the more power to remove obstacles to flow.

The Ups and Downs of Geologic Faults

May 2011
Faults are fractures, breaks and broken zones in the Earth’s crust where one side of the break has moved relative to the other, and they come in many different varieties.

Round Mountain, Nevada

May 2014
There are a number of veins in the disseminated mineralization, but the principle ones on Round Mountain are known as the Los Gazabo and the Keane.

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