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Friday, July 29, 2011

Gold Occurrences in Labrador

The Torngat Mountains of northern Labrador
Photo by Gierdzep

Politically Newfoundland and Labrador are one province of Canada their geological histories are so different that we have decided to treat them as separate entities.  Throughout most of geological time Labrador has been part of the Canadian Shield with some of its far north disturbed by a fairly recent orogeny that raised the Torngat Mountains.  The Torngats are in Quebec, Labrador and a small pert is in Nunavut.  Geologically they are considered the Artic Cordillera with the highest mountain being Mt. Caubvick at 1,652 m (5,420 ft.)  Geographically Labrador contains some of the wildest land on the East Coast of North America to the point it even lacks a trans-Labrador highway.  It is also little explored even though it is known to contain gold.

Labrador in cells contains very few known gold deposits that are more a function of the lack of exploration rather than the fact that gold isn't there. You will find most of the gold in Labrador Inuit southwest corner where it butts up against Quebec.  This is where they build a railroad From Sept Isles Quebec to Labrador city to transport iron from the mines there and Shefferville Quebec. Gold is often associated with iron mines.

There are many geochemical anomalies of gold phoned him the Archean Nain Province where it is associated with strong iron carbonate alteration of the Florence Lake greenstone belt and in quartz base metal veins at the Aucoin showing.  The superior province also contains several areas that show minor gold mineralization where the northern occurrences are associated with metamorphosed iron deposits in the southern ones with pyrite-pyrrhotote-arsenopyrite veining in mafic and metasedimentary gneisses. Gold is also found in the eastern Makkovik province where it occurs as small being hosted the positives in quartz. These are found in felsic volcanic rocks at Poiniadluk Point.  In the southeastern Churchill Province gold is found that the VBE-2 prospect where it is located in the Tasuyak metasedimentary gneiss that contained up to 5.5 grams per tone located in sulfide-graphite rich layers.

Gold is often found associated with greenstone belts that extend across the Archean all the way from Wawa Ontario to past Chibougamau Quebec.  This is such wild country that it has never been thoroughly explored for gold and it is likely that the Abitibi Greenstone Belt extends eastwards into Labrador.

During the mid-1800s my great-grandfather prospected for gold in Labrador where he found enough to make my great-grandmother's wedding ring. Some prospecting was done as early as 1870.

Tuesday, July 19, 2011

Gold Occurrences in Tennessee

A piece of gold bearing copper ore from the mines at Ducktown Tennessee
Photo by Brian Stansberry

Most of the gold in Tennessee occurs in a narrow belt found in Monroe and Polk counties where they come into contact with the North Carolina border. For a distance of about fifty miles in the streams draining down from the Smoky Mountains placer gold deposits are formed.  According to reports placer gold has been discovered in the Caney Fork River around five miles below the Center Hill Dam.  Most of the gold recovered is found as small particles that are dust sized.  However, there are reports of larges sized nuggets as large as 2 or 3 ounces.

According to reports there have been a few nuggets recovered around Knoxville and further north in the area around Bristol, Tennessee.  Recent communications report that there is also gold found in the central Smokey Mountains to the northeast of Knoxville.  The author has seen some photographs of microscopic gold deposited in quartzite from this area.  Gold has also been recovered from the copper sulfide ores mined around the Ducktown area as a byproduct of copper and zinc mining.  

The bedrock map of Tennessee shows that the far eastern border of the state is in the Blue Hills province, a known gold producer that abuts the Valley and Ridge province immediately to the west.  The map indicates that the whole Smokey Mountain National Forest probably contains gold the problem is really one of the idea the place has never been properly prospected.

Bedrock Geological Map of Tennessee.  Most of the gold is found close to the North Carolina in the rock shown as brown. USGs

It was from the Valley and Ridge province where the author saw the photographs of gold in quartzite.  This is a perfect place to find gold as the quartzite and quartz pebble was eroded from mountains that were further east in the Piedmont province of North Carolina.  The Piedmont is peppered with gold mines, and it stands to reason some of this gold would have reached the Valley and Ridge province by the processes of erosion.

Gold has also been found at the Tellico plains as small grains eroded from bedrock of the nearby Unika Mountain on the border with North Carolina.  The Unika Mountains is where the gemstone Unikite is found.  This is a variety of granite with pink feldspar and green pisticite that is cut into cabochons.  The gold is found mixed with the soil from near the summit of the mountain in a stratum of soil that is from 10 to 12 inches deep.

Most of the Gold in Tennessee is found along the eastern edge of the state and rocks that are of Cambrian or pre-Cambrian age. Or also called on the western flank of the great Smoky Mountains as well as in the creeks a few miles east of not those Springs. Another place where it is found is in back of Chilhowee Mountain medicine bottle County. Gold is also found in Polk County on Citico Creek, Cane Creek, Coker Creek and the headwaters of Tellico River. Coker Creek in their own County produced nearly all the gold that has ever been found in Tennessee that according to some authorities about into a little less than $200,000 worth of gold.

Some of the best areas to prospect for gold in Tennessee are a narrow belt of stream gravels that are about 50 miles long in the southern part of Blount, Monroe and pull counties where they are alongside the North Carolina border. According to some authorities some of the best prospect in and be found in the rivers and creeks of Monroe County. Goals also found associated with the many copper mines of Polk County around the Copperhill-Ducktown Square is produced as a byproduct from the copper mines. 

Monday, July 4, 2011

The Chemistry of Gold Extraction: Part 1. Simple Methods

A flotation cell similar to that used in the agglomeration process for gold recovery
by Dhatfield

Due to the complexity of this subject we are going to have to present it in several parts.

There are as many ways of extracting gold from its ores as there are ores it all depends upon which method is the most commercially viable and efficient. If the ore is amenable all that may be necessary is to reduce it to fine particles and extract the gold by gravity separation in water like any other method like panning or using a sluice box. A more advanced system is by using a “shaker table” a device that is slightly tilted in two directions.  The gold bearing fines are added at the top corner of the table with the lighter materials being washed by water off the lower edge of the table leaving behind the gold to be recovered from the surface.  There are several other schemes that have been developed over the years for affecting this process including the widely used “spiral classifier.”

A gold panner using a gold pan the simplest form of gravity separation
Photo by Alan Souter 

Gold agglomeration is a technique that is used for the recovery of gold when it is impossible to use cyanide or mercury because of environmental concerns.  The use of a process called coal-gold agglomeration makes use of a slurry made from finely divided coal and oil that works on the principle that gold is a hydrophobic material that won’t be wetted by water but will be attracted to the slurry.  After the gold has combined with the slurry, the slurry is burned causing the gold to form larger particles that can be extracted using gravity methods using water.

In an actual test of this process gold ore was finely divided and mixed with powdered charcoal, oil and water then stirred briskly for an hour that formed agglomerates containing gold.  Once the gold had formed a suitable agglomerate a collector such as potassium amyl xanthate (PAX) was stirred with the agglomerate for an additional fifty minutes.  The gold bearing agglomerate and the residue gangue was then ashed in a muffle furnace and the gold recovered from the ash using aqua regia. 

Greater gold concentration was obtained by increasing the viscosity of the oil or the increased size of the coal particles.  The rate of gold recovery was also influenced by the rate of stirring.  Stopping before after the optimum amount of stirring decreased the amount of gold recovery. By recycling the agglomerate showed that the amount of gold recovered could be further increased resulting in lowering the costs of the process.

Sunday, July 3, 2011

Fists Full of Gold

Chris Ralph the associate editor of the Mining and Prospecting Journal claims there is still plenty of gold out there for the taking.  The title of his book is “Fists Full of Gold” because he hopes that will be what you have after reading his book.  He has put years of experience in writing this book making it the most comprehensive prospecting book that has ever been written. The focus of the book is to teach you how to find gold deposits and what to do after you have. A lot of information is included in this book that simply can’t be found in other books about prospecting. There is plenty of basic information for beginning prospectors, more information for more advanced prospectors and plenty of information for those prospectors that have decades of experience.  The book holds plenty of the latest technology and up-to-date methods for finding gold.

The book will teach you the skills of being a prospector in an entirely different and unique way that is explained in any other book. Equipment is not the only thing that is explained in this book that also explains the methods of using that equipment. Will the most important things that is covered in this book is where to look for gold, and how to recover the gold. The book was designed to be the only prospecting book you'll ever need, or will ever outgrow. Fists Full of Gold contains more than 360 pages for 225,000 words devoted to the world of prospecting. The book is longer than any other two or three books devoted to prospecting and gold. It's all written in words the average reader can understand that has no training in either geology, prospecting or mining.

The basics of prospecting and finding gold, including:
    The fact that there is lots of gold is still out there to be found
    How to use a gold pan, including crevicing, mossing and sniping for gold
    How to get the best recovery out of your sluice box or highbanker
    How to use a suction dredge to find and recover paystreaks
    How to operate a dry washer for gold
    An extensive section on metal detecting, perhaps the best on the market
Building your own equipment: including building your own:
    Portable sluice box
    Lightweight suction dredge
    Desert dry washer
How to operate a small scale commercial mining operation
How to deal with and get the most out of your black sands
How to get the best prices for your gold, specimens and nuggets
A full coverage of the geology of gold and silver mineral deposits:
    All about minerals and how to identify them
    Minerals associated with gold deposits
    Rocks: what they are and how to identify them
    Basic geology for the prospector in an understandable form
    A detailed explanation of placer geology and how paystreaks form
    A detailed explanation of hard rock geology and how gold deposits form
    How to recognize many types of hard rock gold and silver deposits
How to do research to find your own rich concentrations of gold:
    Using and understanding topographic maps, aerial photos and GPS
    Where to find little known sources of information on gold deposits
    How to use geology maps to find gold
Signs and indicators of gold deposits that you want to look for in the field
    How to read and interpret signs of old timer workings
    How to recognize geologic indicators of gold mineralization
How to prospect for commercial deposits of gold and silver
Mining law and how to stake and maintain your own claim
Platinum placers and deposits – How to prospect for them
Diamonds in placers – How to recognize them
Maps of where to find gold in the US and Australia

Plus hundreds of photos, diagrams and illustrations to explain the concepts presented in the book.

Price USD $29.95   Shipping included!

Please allow 4 to 6 weeks for delivery  

Connecticut residents please add 6.35% sales tax.