History & Geology
The Amazing Mineral Tourmaline
December 2013 by Chris Ralph
It is a gemstone, and yet it is also closely associated with many types of metal ores. It's valuable itself but often points toward other valuable minerals—that is certainly something prospectors want to know more about!
Exploring Iron Oxide Copper Gold Deposits
The excitement over IOCG deposits began with the discovery of a monster deposit at Olympic Dam in Australia in 1976. The discovery was accidental as the operator was searching for strata-bound copper deposits.
Large Gold Deposit Types
It is not necessary to have a PhD in geology, but you need to know the basics, so that’s what I am going to try to dig into here—the understandable basics of these gigantic gold deposits.
Understanding and Prospecting Benches
The most obvious benches are usually near the valley floor, but they can be thousands of feet above the valley floor. Since benches were made by streams, they can contain placer deposits.
Prospecting for Pegmatites
…in some cases pegmatites have produced individual mineral crystals that are enormous, attaining lengths of over 40 feet long, and many of the world’s largest mineral crystals are examples that were found within pegmatite deposits.Northwestern Alaska Mineral Resources
Gold and jade are actually only minor mineral resources for the Northwestern Alaska region as a whole. Modern prospecting has focused more on base metal than precious metal resources.
Exploring and Mining for Uranium
For a time uranium was more popular with prospectors than gold, but this is no longer true, and it has been decades since it was common to see individuals armed with Geiger counters out in the field.
Eolian Placer Gold
I would first like to mention that I am not a geologist. I have, however, spent the last 8 years intently searching for gold nuggets with a metal detector. I have found gold in numerous locations, and in several different types of gold deposits.
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