A Generous Lesson on Detecting Bedrock
May 2019 by Jack Geck
The signal I was hearing was coming from a vertical bedrock crack on the bank of the creek. I removed my backpack, took out my crevicing tools and started to clean out the crack when I saw a glint of gold.
• Can I get advice on a hard rock property in Calaveras County, California?
The big interest to prospectors thinking about the effect of erosion is not what might happen long into the future, but what they might find in the rivers later this summer when the water levels go down.
The type of mine dump that is best for metal detecting are the ones that consist of mixed sizes of rock and are located near some sort of excavation, commonly a shaft or adit. Sometimes the piles located along a trench dug by the miners can be productive as well.
While the Water Board documented the selenium levels in fish and noted they exceed the levels of mercury, they have yet to acknowledge the numerous scientific studies that show selenium effectively neutralizes the effects of mercury.
Lately I’ve been having success utilizing two types of detectors in succession. The first is a pulse induction (PI) detector with a blanket-style antennae, and I follow it up with a very low frequency (VLF) detector.
Most dry washers have a feed rate adjustment. It needs to be set so that the material flows evenly over the riffles and does not bury them.
The technique I will describe is a much safer alternative and it works. It’s a fine-gold panning technique that eliminates the need for mercury amalgamation of most placer samples.
The Bawl Mill • Legislative and Regulatory Update • Ask The Experts - Who owns this historic mill and how do I handle possible mercury contamination? • Ask The Experts - Sampling and assays • The Geology of Diamond Deposits • Keep Watch for The Unexpected • Resurrecting An Old Hard Rock Mine—Gold At Last! • Imagining the Ultimate Prospecting Adventure • Gold Prospecting for Better or Worse: Cold Gold • Gary It's There • Following the Clues • Melman on Gold & Silver • Mining Stock Quotes and Mineral & Metal Prices