History & Geology
The Ups and Downs of Geologic Faults
May 2011 by Chris Ralph
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.
Gold Deposition and Gradients of Placer Streams—Part I
When placer miners from the gold rush era began experimenting with the slope of their sluices, they must have pondered the ideal slope for trapping gold in a creek bed too. Logic suggests the same is true for streams...
Preserving the True History of the Ivanhoe
My partner had the contacts and it wasn’t long before we had an agreement in place and the company had a geologist on site. I recall a time when he was getting the lay of the land, so to speak, and he broke off a rock sample and inspected it with his magnifier.
ICMJ Visits Sonora, CA
June 2023The Giant King Mine
Most gold-bearing veins in this region are controlled by fractures associated with the Melones Fault, a late Cretaceous structure that is 108 to 127 million years old.
Know Your District
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.
Gold in The Midwest--Part I
Gold can potentially be found in all the glaciated areas of the Midwest, but to find it in any appreciable amount one needs to look to areas where the gold gets concentrated by more recent water flows.
How to Recognize Hard Rock Gold Ores
I regularly get inquiries along the line of: “Hey, I found this rock, and I think it might be gold ore. How can I tell?” Prospectors are always on the lookout for gold-bearing rocks that may be the source of any nearby placer gold.
Subscription Required:
The Bawl Mill
• Why Haven't They Mined This Claim?
• Ask The Experts—Where can I find information on the Abby mine?
• Ask The Experts—Is it possible for a mountain range to have good lode gold deposits and yet the area streams not carrying like deposits of gold?
• Ask The Experts—How do you amend a placer claim?
• Ask The Experts—What happened to the BLM web site geocommunicator.gov?
• Fountain of Youth Gold
• Legislative and Regulatory Update
• Suction Dredging Update for California & Idaho
• The Disappearance of State Mining Departments
• The Golden Streams of Butte County, California
• Melman on Gold & Silver
• Mining Stock Quotes & Mineral and Metal Prices
Free:
One Question, Forever Unanswered—Did He Really Find the Gold?
