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.
Additional articles that might interest you...
Which Specific Gravity Test Works Best?
August 2011
Have you ever wondered how accurate specific gravity tests are in determining the amount of gold in a specimen?
Have you ever wondered how accurate specific gravity tests are in determining the amount of gold in a specimen?
There’s Still Gold In Oregon’s Umpqua River
January 2008
The Umpqua River, located in the heart of western Oregon, flows for several miles nearly alongside Interstate Highway Five.
The Umpqua River, located in the heart of western Oregon, flows for several miles nearly alongside Interstate Highway Five.
The Bawl Mill
September 2006
• Lock ‘em up and throw away the keys
• Snow White and the 9 Justices?
• Child support wasn’t her “Primary” concern...
• Burglar makes a clean getaway
• Lock ‘em up and throw away the keys
• Snow White and the 9 Justices?
• Child support wasn’t her “Primary” concern...
• Burglar makes a clean getaway
The Gold Hill and Iowa Mine, Boise County, Idaho: 1863-1895
April 2002
In August 1862, prospectors from Walla Walla, Washington, led by George Grimes, discovered gold near the present townsite of Pioneer City. Grimes was killed by Indians shortly after the discovery. The remaining argonauts retreated to Walla Walla. On October 10, 1862, 52 men returned to Grimes Creek. They built a fort and several cabins before continuing their quest for gold.
In August 1862, prospectors from Walla Walla, Washington, led by George Grimes, discovered gold near the present townsite of Pioneer City. Grimes was killed by Indians shortly after the discovery. The remaining argonauts retreated to Walla Walla. On October 10, 1862, 52 men returned to Grimes Creek. They built a fort and several cabins before continuing their quest for gold.
Drywashing Alluvial Placers
October 2000
Portable, hand-operated, bellows drywashers have been used for over a hundred years to recover gold in the deserts of Arizona, New Mexico, California and Nevada. Drywashers were considered a last resort over...
Portable, hand-operated, bellows drywashers have been used for over a hundred years to recover gold in the deserts of Arizona, New Mexico, California and Nevada. Drywashers were considered a last resort over...
Legislative and Regulatory Update
November 2012
• BLM to raise fees again
• Roadless Rule stands
• Suit filed over dredging restrictions in Washington State
• NWMA lends support
• California suction gold dredging lawsuits progressing
• BLM to raise fees again
• Roadless Rule stands
• Suit filed over dredging restrictions in Washington State
• NWMA lends support
• California suction gold dredging lawsuits progressing
Governor Tells Industry He Will Consider Tax Cuts
March 1999
Gov. Bill Owens announced to members of the mining industry that he would consider a proposal that provides significant tax reductions for mining companies.
Gov. Bill Owens announced to members of the mining industry that he would consider a proposal that provides significant tax reductions for mining companies.
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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
