Gold Deposits in Skarn
July 2003 by Edgar B. Heylmun, PhDSkarn consists of coarse-grained calcium, magnesium, iron, and aluminum silicates formed by hydrothermal solutions, which replace limestone or dolomite near the contact with an igneous intrusion. The contact metamorphism is usually caused by an intrusion such as quartz monzonite, granodiorite, or similar rock type, which may or may not be mineralized.
While mapping, I also found rock chips in the soil that were characteristic of the same wall rock alteration that occurs adjacent to the known lodes in the greenstone belt.
I thought things started off okay until I realized I had forgotten some of my gear and had to return to the house. My troubled start was not helped when my boy came up to me a few minutes after my return to show me his first nugget of the day.
It turns out the old Anaconda Co. really did have 10,000 miles of tunnels beneath this mining city. That’s one of the findings by researchers who have produced a new map that charts the thousands of underground mine shafts here, providing a detailed look at some of Butte’s mining history.
Q: Where is the best place to prospect for gold in Minnesota?
• Show of support needed for anti-EPA bills
• Arizona mining data now online
• California suction dredge hearings
• Update on Forest Service abuse in Washington
Excerpts from California Mining Journal, our original title, published 50 years ago this month.
The Bawl Mill • Our Readers Say • PLP Members Win Occupancy Case—Appeals Continue • Prospecting for Iron in Alaska • Picks & Pans: Highbanking on the American River • Platinum Firm, Palladium to Remain Weak • Spencer Opal Deposits, Idaho • Company Notes • Hillside Placers • Elko Mining Expo a Success • Gold Prospecting in Alberta • National Mining Hall of Fame to Induct Six • Mining Stock Quotes and Mineral & Metal Prices • Melman on Gold & Silver • Looking Back