How a Gold mine is Created

An open pit gold mine.
Photo by Patrick Huber

A recent question that was posed to the author on www.allexperts.com was how a gold mine came into being.  The questioner realized that a gold mine is usually large, but how they came into being just eluded him.  He thought spelunkers, cave explorers, discovered the gold minerals while exploring the cave.  A few working gold mines probably were discovered this way.  Most gold mines are purpose dug excavations with three types of gold mines that are recognized.  The people that develop a gold mine are called gold mine developers.  Although it is nothing more then a large construction job there are enough differences so sometimes this is a specialty in the construction industry.

A gold nugget from a placer mine.
Photo by Rob Lavinsky

The first of these gold mines is the placer gold mine where through the process of weathering the valuable gold minerals are released from the bedrock that encloses them.  Most of these deposits find their way through the process of soil creep to an ocean or river where they are found in the bedload mixed with many other lighter gold minerals.  Another type of gold mineral deposit found is the result of weathering in place.  The deposits are usually found in the tropics between 32 degrees north and south of the equator.  Many of these are found associated with quartz that remains in place while the other gold minerals are turned to clay around them.  The gold and other gold minerals stay more or less in place waiting to be gold mined.  A placer gold mine is usually limited to gold production although there are exceptions to the rule other placer gold mines also produce tin and rare earth gold minerals.

Entrance to a gold mine adit in Japan.
Photo by PHGCOM

Other gold mines are located in bedrock, and usually are called lode gold mines if they are for mining gold.  Basically there are two types open cast that is nothing other then a large hole in the surface of the earth.  The other type of bedrock is one underground.  Gold mines of this sort are further subdivided by their way of entrance.  One type of gold mine has a shaft going into the ground with tunnels reaching out from the bottom of the shaft.  Some of these gold mines have several layers reaching out from a central shaft.  Other gold mines of this sort have more then one shaft entering the gold mine.  The other type of bedrock gold mine uses an “Adit”  that is a tunnel going more or less horizontal to the surface of the ground.  It costs less to build a gold mine with an adit then one with a shaft.

Headframe of the Oryx gold mine in South Africa.
Photo by Babakathy

Before any gold mine is created there must be lots of preliminary work done first.  Placer gold mines are called “poor mans gold mines” because the preliminary work is often kept to a minimum.  The work can be done by one man or a small workforce.  Bedrock gold mines are for more capital intensive then a placer gold mine sometimes for a truly large gold mine it exceeds 1 billion dollars before any ore is extracted.

Gold found in Roads and Sidewalks

A small gold nugget that can be found in sidewalk cracks.
Photo by Rob Lavinsky

The last place you would ever expect to find gold is around roads and sidewalks, but according to our spies it turns out that these are excellent places to search for placer gold. The sidewalk or road all have cracks, and a surface that is ideal for catching gold.  There may not be much, but over time the cracks can collect quite a bit of gold particles.  Another place where gold will collect is on the side of roads or sidewalks.  It has been reported to us that at least one man makes a living from the gold he collects from sidewalk cracks in New York City.

A good place to look for gold is at the sides of roads, or cracks in the pavement/
Aron C's Photos

This doesn’t only work in New York, but can work anywhere’s there are roads and sidewalks.  Obviously it will work better in places where there are existing gold mines like in Timmins, Ontario or Washington, DC that is in the middle of the Appalachian Gold Belt.  Just think about that panning for gold in the middle of our nation’s capitol.

Gold in cracks is going to require some different tools then the average gold miner would think about, although many of them can be found in the average kitchen like a broom and dust pan.  You can’t pan for gold in the middle of the road so you’ll need a plastic bad with a zip top to hold your concentrate until you get home.  Other handy tools include a paint brush, a small carpenter’s level, a magnifying glass and some kind of metal hook to get the gold bearing sand out of the cracks.  A battery powered vacuum cleaner is a nice addition, but not necessary.

Gold lurks in the cracks found in sidewalks.
Photo by Christopher Beland

The carpenter’s level is so you can check the slopes to see which way the gold has traveled.  The broom is for sweeping the sidewalk; the brush is for getting into the cracks.  The vacuum cleaner can be used in place or the broom or brush.  The dustpan is for collecting the dirt from the road or sidewalk.  The plastic bag is to put what you have collected into before taking it home where it is finished.

The major source of this gold it from what is carried onto the sidewalk from peoples feet.  It takes several years for the accumulation of gold to build up enough to be worthwhile.  On roads the gold comes from road sand in colder places, or from gold that is carried onto the road by tires.  Most of this gold migrates to the side of the road by the action of runoff, where it is found right next to the side of the road. 

There are many other odd places where gold can be found especially if you are prospecting around old ghost towns.  Some of the best places to look is where there were former salons or bordellos.  Just remember the old saying; gold is where you find it!

Money Dries-Up for Juniors

The NYSE
Photo by Luigi Novi

Even in the best of times junior mining and metal companies have a hard time finding investors and as of October 2011 it’s becoming a hard-scrabble existence to find any at all.  These are times when the whole world is suffering from a king sized case of economic blahs, where it seems one calamity after another is leaping out of the woodwork to make investors nervous about where they put their money.  Darn little of it is available for investing in mining causing many miners to take some really creative ways of getting the investors to part with their money.

The trouble started last March when Japan was struck with a devastating tsunami.  It was then that investors started pinching their money giving junior miners a tough row to how for their money.  The market started to slow down then, and by October had ground to a dead halt. Junior miners are the first ones to take a hit in the slowed down economy where they have traditionally gotten their financing.

Cash money!
Photo by Revisorweb

According to one investor money has been flowing away from the juniors that wont change until the financial panic affecting the whole globe reduces slightly.  In the third quarter of this year the market had slowed down finally coming to a dead stop after the 1^st and 2^nd quarters where the cash flow was slowing down.

Mining Stock from Tombstone, Arizona in 1883

 The real problem is whether we are sliding back into a recession or not.  That is the $64 question.  One mining company investigating a gold/silver deposit in Africa has promised its investors more then just stock they’ve also promised each investor two ingots of silver each weighing ten pounds.  If you need to raise more money you are going to have lots of trouble.  Investors are more selective about who gets the money.  Many of the deals being cut now are for just enough money to limp along.  Many investors are just maintaining the status quo for the next three to six months.  It is expected that the future is going to bring with it some relatively expensive financing.  This doesn’t mean there is no money, but if you had to raise a few million dollars, you’ll have to work for it.

As it was put by one investor, “Lots of investors have cash but the mentality right now is: why should I buy this week, if next week I can get it much cheaper.”

Discovery of Gold sparks mini Gold Rush in southeast United States

Crystalline gold   USGS

According to a report from Reuters recently a Canadian Mining Company along with a tiny town in South Carolina are leading the charge to what could become a modern gold rush in the southeastern United States.  The company from Canada is Romarco Minerals Inc. that has reopened the old gold mine at Kershaw, S.C. and by 2014 should be pouring its first gold bar.  The name of the mine is the Haile Mine.  The author originally became aware of this exploration project at the PDAC Show in Toronto in 2008.    

The Haile mine once environmental studies and the permitting process is completed will be the first modern gold mine is the Mississippi River since the Kennecott Minerals Mine that was in Ridgeway, South Carolina in 1999. Based on proven gold reserves that were found in the samples it is estimated that 3.1 million ounces of gold still remains in the ground at Haile. It is estimated this gold mine will produce an average of 150,000 ounces of gold for the next five years.

The slate belt that winds its way through the southern Appalachians from Maryland to Alabama was the site of the first gold rush in America before gold was discovered in California in 1848. It is interesting to note that this Slate belt north all the way to Quebec. Gold is been reported that sparked a gold rush in Columbia County and adjoining parts of Saratoga County, New York, and western Vermont in the northern extension of the slate belt. It's one of the most significant gold belts in the United States and sparked one of our first gold rushes in the early 1800s.

This is the first time that the southern gold belt has been explored using modern methods, an area that many people have forgotten how significant gold production was in the past. Most gold mines in the area were discovered by following placer deposits to their source. The glacier that destroyed the placer deposits in the northern United States and Canada has acted to prevent the discovery of gold deposits in the northern extension of the Slate belt.

Finding the gold left it daily has sparked renewed interest throughout the Slate belt in the southeastern United States. The gold found here is embedded in microscopic flecks in the volcanic rock in the so-called Carolina Slate Belt that extends from Alabama through northern Georgia, the Carolinas, Virginia and Maryland. In early October another Canadian mining company from Vancouver, Revolution Resources started investigating other old gold mines in the slate belt including the first mine, the Reed Mine in North Carolina.

During the period after the discovery of gold in North Carolina and the Civil War there were hundreds of gold mines scattered throughout the piedmont region of the southern states. Many of these gold mines were destroyed by the Union forces during the Civil War, others remained in production until 1942 when the federal government closed all the gold mines in the United States. There was even the working gold mine at the Great Falls of the Potomac River just upstream from Washington DC that was included in the shutdown of all the mines. Very few of these mines ever reopened and for the most part have been forgotten.

Gold Occurrences in Saskatchewan

Many of the people living in Saskatchewan don’t realize that the province is the largest producer of Uranium in Canada but also has or had some world class gold deposits that are found in the northern part of the province. The starting point for all this mining activity is the city of Saskatoon where many of these mining companies are headquartered. The potential of the province where the surface geology has barely been scratched is vast with many mineral deposits yet to be found.

Rumors of gold being found by trappers on the North Saskatchewan River started filtering out in 1859. These rumors claimed there were one ounce and larger nuggets being found were prevalent during the building of North Battleford. Flour gold can still be recovered by panning the river from Churchill west to Edmonton Alberta and beyond. Some stories even tell of seeing businessmen with their pants rolled up panning gold from the river during lunch hour around Edmonton Alberta.

Gold was first discovered in Saskatchewan near Prince Albert in 1859 in the North Saskatchewan River. The province began producing gold in small quantities in the early 1900s from placer deposits along the North Saskatchewan River and its tributaries. Today there five gold mines have been brought into production since 1987 with additional production coming from base metal mines mainly from around Flin Flon. There are an additional 200 gold occurrences in the province that are not being worked presently.

During the 1980 although gold had been produced since the early 1900s marked the first time that there had been a significant gold exploration program had been used in the province. Most of these occurrences are in the Precambrian shield area except for some small placer deposits draining off the Canadian Shield.

According to the Saskatchewan Geological Survey (SGS) there are still large areas in the Province that haven’t been explored especially in the Canadian Shield. To search for Saskatchewan occurrences of gold, use the Saskatchewan Mineral Deposits Index searchable database, or the Geological Atlas of Saskatchewan. Or open the Mineral Resource Map of Saskatchewan.http://upload.wikimedia.org/wikipedia/commons/2/2b/Saskatchewan-map.png

It has been pointed out to me by one of my Canadian prospectors whose mother was born in Battleford, SK that they mined placer gold along the Saskatchewan River flowing between Battleford and North Battleford.  Some of the miners reported they were able to recover as much as an ounce a day.

Why there is little or no Placer Gold in the Northern US or Canada

The answer is simple; the action of the glacier destroyed the placer gold deposits. It is hard to realize that the last period of continental glaciation lasted until about 12,500 years ago when the glaciers started to recede. The northern U.S. and Canada were covered with ice sheets that were up to two miles thick. It was the grinding action of this glacier that destroyed most placer deposits of gold.

Two exceptions to this continental glaciation can be found in Alaska and Northeastern Siberia. This whole area was largely ice free due to its arid climate during the period of continental glaciation. In Alaska this left the Tintina Gold Belt largely uncovered giving rise to two of the greatest gold rushes of modern times; the Klondike and the Fairbanks rushes. In Siberia extensive placer deposits of gold were found in the Kolyma River Basin that gave rise to the slave labor camps that were known as the Gulag. This area was above water during the glaciations and was known as Berengaria a continental landmass of continental proportions. Berengaria provided a land bridge between Asia and North America allowing the migration of animals and mankind from one to another.

Due to the grinding action in a large glacier it is doubtful that little or no gold in the northern U.S. had its origin in Canada. To be reduced to fine powder gold it wouldn’t have to travel too far in a glacier with a top figure of around 300 kilometers.

The thin placer deposits found in New England are more likely have been derived from lode deposits buried under the covering of glacial till that for the most part is around 4 meters deep and can range to well over 100 meters. We have personally observed lode gold deposits in place making it virtually possible that if you are finding placer deposits larger then gold dust that it has its origin in buried lode deposits.

In New England the glacier traveled roughly northwest to southeast. On one occasion we observed a gold nugget from a stream in western Connecticut that weighed about a pound. This nugget was barely rounded and was at least one-half quartz, a clear indication it hadn’t traveled too far from its source. For that reason we would like to have reports of any placer gold found in New England larger then flour gold. You can reach us at geotekllc@gmail.com.

John Angus Carter School of Prospecting: Module #1

We are pleased to announce our new online modules about prospecting that are capable of being used over the entire world to learn how to be an effective prospector and miner of gold and other valuable minerals including gemstones.  There is going to be a series of these modules offered at the reasonable cost of US$10.00 per module.  The first of these modules is, “What is Placer Gold and where it’s Found.

In addition to our prospectors school we are also available as a speaker within a radius of 100 miles around Barkhamsted Connecticut including Boston and New York City on gold mining and prospecting.

All the modules will be presented in Microsoft PowerPoint and will be emailed to you as attachments.  They will be opened in PowerPoint that is a regular part of MS Office or in Open Office Presentation.

The first of the modules is about finding placer gold that is sometimes called, “Poor man’s gold” and the environments where it’s found.  The module is well illustrated with accompanying text.  Like all modules its price is US$10.00.  The modules can be paid for with credit card, money order or via PayPal.  The module will be emailed to you within 24 hours of receipt.

If you want to mail us a money order for your module the address is

John Carter

11 Meeting House Rd.

Barkhamsted, CT 06063

Email geotekllc@gmail.com

You can order the modules from this list:

What’s that in the bottom of your gold pan?

Iron oxide that has been removed from gold concentrate with a magnet.
Photo by Peter Kuiper

Gold isn’t the only thing that ends up in your gold pan, although with a density of 19.1 it is one of the minerals that might be staring up at you.  Platinum or platinum group metals (PGM) having a density almost matching gold is another.  The rest of the odds and sods found with the rest of the black sands can range from a to z with zircon the last.  They can be divided into several different classes with iron oxides being one of the most abundant,

Iron Oxides:

Magnetite:  This is mixed with hematite on about a 50-50 ratio.  Magnetite can be removed with a common magnet.  This mineral is opaque black and is a member of the spinel group of minerals.

Hematite:  This is the second most abundant mineral found in the bottom of a gold pan. Unlike magnetite is can’t be removed with an ordinary magnet, but is attracted to a rare earth magnet.  Both magnets are used in the process or removing iron oxides from gold concentrate.

Iron bearing sulfides:

Pyrite: this is also called “fool’s gold” because it resembles gold but can be recognized by its rotten egg smell when tested with acid. Pyrite is brittle whereas gold is malleable.

Chalcopyrite:  The same tests apply as to pyrite except chalcopyrite is somewhat redder then pyrite.

Arsenopyrite: this occurs as silver colored cubic crystals that look like pyrite.  The simplest test is made by striking one of the crystals with a hammer when it emots a garlic smell.

Corundum:

This is aluminum oxide with a hardness of 9 on the Moh’s Scale that includes rubies and sapphires.

Diamond:

This is the hardest mineral of all with a hardness of 10 on the Moh’s Scale.  It occurs as a bypyramidal crystal.   

Uranium/Thorium:

There are several minerals present in stream heavies that contain these elements the most common are pitchblende, uranite, columbite/tantalite and allenite.

Tungsten:

The two common minerals of this element are wolframite and scheelite/  Both of these minerals fluoresce under ultraviolet light in a bluish/white glow.

PGMs:

Platinum group metals occur with gold on about a 5 to 1 ratio with more gold.  They look like steel and like gold are quite malleable.  They also leave a silver streak on a touchstone and are not affected by any acid except aqua regia a mixture made from 1 part of nitric acid and three parts of hydrochloric acid.

A zircon crystal
Photo by Rob Lavinsky

Zircons

These are the ore of zirconium that has many uses in modern technology.

Many of these minerals themselves are ores for their various elements.  In many places they are actually mined from beach sands for their metal content in places like Australia of the Southeast United States using specialized equipment mainly the spiral classifier.

Generally, any mineral with a hardness of 7 on the Moh’s Scale and denser then 3 will wind up in the bottom of your gold pan.  We did not include complete descriptions of these minerals because there are more then adequate descriptions available at www.mindat.org. :

year of the priest

year of the priest