Geology and stories from the past
Benches and Fossil Placers
March 2013
Unfortunately for us mortal humans, we have a poor perspective on geologic time. When we look at a landscape such as a stream valley, we see it only in two, or at the most, three dimensions. We have poor comprehension of the valley’s fourth and most important dimension—time.
Unfortunately for us mortal humans, we have a poor perspective on geologic time. When we look at a landscape such as a stream valley, we see it only in two, or at the most, three dimensions. We have poor comprehension of the valley’s fourth and most important dimension—time.
The Many Facets of Iron
March 2013
I’ve been fascinated by iron minerals for many years. So let’s take a look at this very interesting and colorful element.

Refractory Gold Processing
February 2013
After your excitement peaks when you first receive the high gold assay from the vein you just exposed, you ponder how you will extract and sell your gold. You will need to develop a flow sheet for your process to optimize your recovery and minimize your costs and permit requirements.
After your excitement peaks when you first receive the high gold assay from the vein you just exposed, you ponder how you will extract and sell your gold. You will need to develop a flow sheet for your process to optimize your recovery and minimize your costs and permit requirements.
All About Garnets
February 2013
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.

Heavy Sands Mining
February 2013
Lately my mind has been involved with group 4 of the transition elements, namely titanium, zirconium, and hafnium. They all have similar chemical properties. Of greatest interest to economic geologists and miners is that these valuable elements often occur together in sands.
Lately my mind has been involved with group 4 of the transition elements, namely titanium, zirconium, and hafnium. They all have similar chemical properties. Of greatest interest to economic geologists and miners is that these valuable elements often occur together in sands.
Using Vegetation and Soil Conditions as Prospecting Aids
January 2013
Wouldn’t it be great if you could know if there is gold in the ground without setting foot on the ground? Well you can, to a certain extent, if you can recognize mined ground from unmined.
Wouldn’t it be great if you could know if there is gold in the ground without setting foot on the ground? Well you can, to a certain extent, if you can recognize mined ground from unmined.
Prospecting for Diamonds
January 2013
Let’s take a look at diamonds and diamond mining and see how they form, how they are used beyond just jewelry, and what leads geologists to find diamond deposits.
Let’s take a look at diamonds and diamond mining and see how they form, how they are used beyond just jewelry, and what leads geologists to find diamond deposits.
Mineral Deposit Trends: Real and Imaginary
December 2012
One of the most important things prospectors do is work to figure out where to go prospecting. Along with understanding the basic geology and putting yourself in a favorable area, one of the things a prospector might consider in finding a location to search is the existence of mining belts also known as mineral deposit trends.
One of the most important things prospectors do is work to figure out where to go prospecting. Along with understanding the basic geology and putting yourself in a favorable area, one of the things a prospector might consider in finding a location to search is the existence of mining belts also known as mineral deposit trends.
The Struggle to Reopen Alaska's Largest Gold Mine
November 2012
The historical AJ mine, located east of Juneau, Alaska, was considered the largest gold mine in the state at one time. Joe Juneau and Richard Harris struck gold there in 1880, and it has been more recently known as a tourist destination.
The historical AJ mine, located east of Juneau, Alaska, was considered the largest gold mine in the state at one time. Joe Juneau and Richard Harris struck gold there in 1880, and it has been more recently known as a tourist destination.
The Rush to Treasure Hill
November 2012
There were some exceptional times in the far-flung history of the West. Rich finds of minerals that set men’s souls ablaze. From the rich gold fields of California, men who arrived too late to find riches went searching in every direction. The trail that we will follow leads east, past the shining silver district of the Comstock Lode.
There were some exceptional times in the far-flung history of the West. Rich finds of minerals that set men’s souls ablaze. From the rich gold fields of California, men who arrived too late to find riches went searching in every direction. The trail that we will follow leads east, past the shining silver district of the Comstock Lode.
The Verde Copper-Gold-Silver-Zinc District, Jerome, Arizona
October 2012
When I was a student in the College of Mines at the University of Utah, the Verde district was used as an exploration model for “submarine volcanogenic massive sulfide deposits.” So I looked forward to visiting this district and the town of Jerome in central Arizona in the spring of 2012.

Potholes and Other Bedrock Traps
September 2012
Potholes in bedrock can trap placer minerals and even be glory holes. They are, at least, interesting geologic phenomena, and at best, a treasure trove of gold nuggets.
Potholes in bedrock can trap placer minerals and even be glory holes. They are, at least, interesting geologic phenomena, and at best, a treasure trove of gold nuggets.
Ask the Experts: VMS ore
August 2012
Q: Are there any mills that handle VMS ore?
Q: Are there any mills that handle VMS ore?
Gold Depositiion and Gradients of Placer Streams—Part II
July 2012
The steeper the gradient is, the more potential erosive power to move gold and other bedload sediments, and the more power to remove obstacles to flow.

Prospecting for Copper Ores—Part II
July 2012
Copper is a critically important metal that we need to run our modern electronic society, and the long term outlook for this metal is for a steady increase in price.
Copper is a critically important metal that we need to run our modern electronic society, and the long term outlook for this metal is for a steady increase in price.
Gold Deposition and Gradients of Placer Streams—Part I
June 2012
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...

The Wisdom of Mark Twain—And Tales of Cheating the Unwary Prospector
June 2012
I (enjoy) Twain’s description of a gold mine, “A hole in the ground with a liar at the top.” Some humor here? You bet, but I’m sure he meant it to be a real eye opener as well.
I (enjoy) Twain’s description of a gold mine, “A hole in the ground with a liar at the top.” Some humor here? You bet, but I’m sure he meant it to be a real eye opener as well.
Fabulous Florence—The Golden Town of Idaho
May 2012
In September 1861, on a round-about prospecting journey homeward, five California gold miners discovered gold in the area now called Florence. While watering the horses, one of the men noticed a golden color on a piece of slate bedrock in the stream...
In September 1861, on a round-about prospecting journey homeward, five California gold miners discovered gold in the area now called Florence. While watering the horses, one of the men noticed a golden color on a piece of slate bedrock in the stream...
Arizona's Vulture Gold Mine and Lost Dutchman
May 2012
When prospectors and treasure hunters talk of gold in Arizona, it is the Lost Dutchman or Vulture mine they usually think of. The Lost Dutchman gold mine is just that—a myth chalked full of holes that has been embellished over time as any good legend should be.
When prospectors and treasure hunters talk of gold in Arizona, it is the Lost Dutchman or Vulture mine they usually think of. The Lost Dutchman gold mine is just that—a myth chalked full of holes that has been embellished over time as any good legend should be.
Critical Metals: Copper
May 2012
From time to time I’ve been doing a series on critical metals and how important they are to our complex and technological society. This month we are going to take a look at copper, and how important that metal is to our modern lives.
