All Articles
Mineralized Calderas in Colorado
May 2002 by Edgar B. Heylmun, PhD
A caldera is a large circular volcanic depression caused by collapse due to the removal of molten magma from an underlying magma chamber. The removal of magma is due to explosive venting of lava and pyroclastic material.
Feds Sue California over Sales of Public Lands
They cited concerns that the Trump administration would allow more logging, oil drilling, mining or development on some of the 46 million acres controlled by the federal government in California.
Searchers' Dreams
The story began in a southern Arizona mountain range...
Tantalum
Tantalum is a refractory metal which is non-toxic, ductile; easily fabricated, has a high melting point, is highly resistant to corrosion and is a good conductor of heat and electricity. It has the unique ability to transmit an alternating current in only one direction.
The Snapshot
Once all the numbers from all the samples and water tests are compiled, a snapshot of the performance of each tank in the process circuit can be seen side-by-side.
Ask the Experts
Can I treat a sample with muriatic acid?
Looking Back
Excerpts from California Mining Journal, our original title, published 50 years ago this month.
MMAC Update
After many decades of closures, land-use restrictions, and over-regulation, miners and all other public land users may finally see some real relief due to the efforts of MMAC.
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The Bawl Mill
• Our Readers Say
• California Wilderness Coalition and The Nature Conservancy Recruit Government Employees to Carry Out Huge Land Grab
• Drywashing Rules Clarified
• The Keystone Gold-Copper District, Medicine Bow Mountains, Southeastern Wyoming
• Picks & Pans: Mining Tungsten Ore—A Case History
• Gold in Oregon
• Aussie Gold—A Look at the Northern Territory
• The Phoenix Gold Mine: A Brief History
• Calico Mine
• Mining Stock Quotes and Mineral & Metal Prices
• Looking Back
• Melman on Gold & Silver
