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The Golden Triangle of Sonora, Mexico
May 2001 by Edgar B. Heylmun, PhD
The “Golden Triangle” dry placer district in Sonora, Mexico, lies some 80 to 100 miles south of the border. It is in desert terrain at elevations between 1,900 and 2,300 feet above sea level.
Understanding Skim Bar Placers
Perhaps the most notable thing about skim placers is that they form on the top surface of gravel bars, as opposed to coarser gold placers where the weight of the gold particles allows the gold to settle down on or near bedrock.
The Swift Shore Mine 1862—Present
Michigan Bluff is an old mining town dating back to the 1850s. It is located in Placer County, about 25 miles northeast of Auburn, just past the town of Foresthill. It sits on the very edge of a mountain, with the Middle Fork of the American River flowing about 1200 feet lower at the bottom of the canyon.
Ask the Experts
Questions regarding processing black sands
Potential Gold at Old Hydraulic Sites
So why would a modern-day prospector want to learn about a method of mining that was banned by the courts more than a century ago?
Gold: Is It Everywhere?
Gold, on the other hand, is super rare, and is one of the rarest elements in the earth’s crust. It averages only 0.000004 percent of the earth’s surface. That is four parts in a billion.
Melman on Gold & Silver
Unquestionably, it was the other side of the Atlantic Ocean—that is the European side—that provided virtually all the political, economic and social fireworks during the past month.
The Bawl Mill
- ESA wants a big win, not a win-win
- By The Numbers...
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The Bawl Mill
• Original Sixteen to One Goes to Court—Challenges MSHA Citations Part II
• Using Legal Subdivision
• Placer vs. Lode Gold
• Gold Tellurides: Tellurium, an Assay Impurity
• Court Hears Arguments Over Rights to Shipwreck
• Picks & Pans: How to Succeed in a Small Mine, A Case History: 1990-2000
• Charcoal Crucible Recipe
• Discovery of the Mountain Pass REO Deposit
• Romance of the Old Silver King
• Record-Breaking Alaskan Nugget for Sale
• Company Notes
• Nevada Gold Production Up Despite Lower Prices
• Gold in Guatemala
• Bush Taps Utah Resident for Labor Post
• Looking Back
• Melman on Gold & Silver
• Mining Stock Quotes and Mineral & Metal Prices
• Honda Pares Down Use of Precious Metals in Autos
