Old Mine Sites and New Technology
September 2018 by Jack Geck
We’ve had two trips to the deserts of Nevada and explored mines and mill sites, hiked miles of ravines in California, and swung our detector coils over thousands of square yards of bedrock.
I looked over and saw Ben on his knees, digging at the edge of the Manzanitas, almost underneath them. I thought back to the previous weekend when we were planning this trip—that day had been a “Ben day.”
Sanders claimed he used ground-penetrating radar to survey his private property in Nevada County, California, and uncovered the chunk of gold with a backhoe when he was following up on one of the anomalies found by the radar.
While a large number of locations have yielded some placer gold, most of the state’s placer production has come from a few productive districts.
In this article I am going to talk about the different sources of gold and the clues a prospector can follow to find the source.
I get a lot of questions from prospectors about garnets, their value and what they tell us about the geology of some types of mineral deposits. So I thought it would be a good idea to take a closer look at the lowly garnet and learn a bit more about it.
Once a seam is found it can be traced for miles in either direction. While you are tracing a clay line, you are looking for indicators. The indicators that I look for are ironstone, hematite, different color clays intermingled with the clay line, and a very iron-rich, brown gritty soil.
Depending on the ore and if significant sulfides are present, a hard rock miner may be able to get away with simply using a flux to digest the other minerals that may be present.
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