History & Geology
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 Golden Streams of Butte County, California
Even though these were some of the earliest placer deposits to be worked, there is still plenty of gold left today—it just takes more work to recover. Knowing about the old locations where gold has been found is the first step to success.
Placer Gold Deposits of Utah
The placer deposits of Utah occur in two distinct types of environments. These are 1) placers found adjacent to, and derived from, gold, silver and base-metal deposits; and 2) placers found in major rivers and derived from unknown, distant sources.
The Miner’s Switchback
Common thought is the switchback slows the velocity of the rushing water and gold drops out from the cut bank to a fill gravel bar within or below the switchback. I am not going to disregard that model; however, I hope to improve upon it.
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.
The Basics of Geophysical Exploration
In developing a mineral property or mining claims, one of the first goals is to identify and quantify valuable deposits. The classic method of doing this is by drilling holes into the ground to sample what is below the surface. The problem is that one or two holes usually are not going to tell you a whole lot...
The Heavy Minerals in Your Concentrates
The fact that mineral deposits can contribute specific types of heavy minerals is why the analysis of the heavy mineral concentrates in the streams of an area can be an important prospecting technique for finding undiscovered mineral deposits.
SS Central America Gives Up Millions in Gold Rush Era Gold
A treasure-seeking young man whose name will forever remain anonymous made the months-long journey either over land or by sailing ship to California after word spread about the gold strike in 1849.
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