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Saturday, January 29, 2011

Where Gold Originated

All the gold on Earth of for that matter all the gold in our universe came from the explosions of supernovae billions of years ago.  When our universe was born in the Big Bang the only element that existed then was hydrogen, and all the other elements were built from this single building block by the process of nuclear fusion.  The next element formed was helium that is composed of two electrons, two protons and two neutrons.  The rest of the elements were built from these simple building blocks including gold.

This is an incubator for stars and solar systems   NASA

Our solar system was formed out of a cloud of cosmic dust that included all the elements that we were ever going to have including gold.  This cloud assumed a disk shape where as the result of gravitational collapse the sun appeared first surrounded by the leftovers that as eddies developed in the cloud produced the planets by further gravitational collapse.  All the bodies whether they were asteroids, comets, meteors, moons, planets or whatever were formed from the leftovers including gold.

The force of gravity collapsing caused this steller material to heat up causing the heavier elements to become segregated, and migrating to the center of the planets including the earth.  This migration of elements was also a function of the atomic radius of the various elements.  Iron and nickel having relatively small atomic radii formed the center of the earth.  Elements with larger atomic radii like gold and other metals remained behind in the mantle of the earth. 

A subduction zone in action.
By R>J> Stern

One of the prominent features displayed by our planet is the development a circulation of heated mantle that allowed molten magma to surface in the form of hotspots that are still with us in places.  Eventually however they merged to form the so-called spreading centers where basalt rises up from the mantle driving the phenomenon we know as plate tectonics as well as creating the part of the crust we know today as seafloor.

The seafloor contains all the elements found on Earth in various proportions including gold.  This part of the crust isn’t watertight allowing ocean water to penetrate it for a depth of several miles.  This water contains several dissolved salts that under the conditions encountered deep in the crust of the earth can raise this brine to a heat greater then 1,000 Celsius that leaches the various metals out of the crust.

At the spreading centers the dissolved elements including sulfur that combines with most of the metal ions forming sulfides.  However there are a few metals like gold and the platinum group metals that do not combine with sulfur that are called “noble metals” that are precipitated from their metal chloride state when they are cooled sufficiently.  These metals are deposited with the metal sulfides around the black-smokers found associated with the spreading centers.

Metal sulfides deposited on quartz and apatite.
Photo by

The crust of the Earth varies in thickness from six to twenty kilometers in thickness, and is composed of two types of crustal material that are called by geologists “sial” and “sima.”  Sial is composed of rocks that are rich in silicon and aluminum that forms continental crust.  Sima is composed of rocks that are composed of silicon and magnesium rich rocks that form oceanic crust.  Sial is less dense then sima, so it floats on its surface.

A subduction zone is represented by a long deep trench that is parallel to a continental mass where the sima dives under the sial carrying with it not only all the elements that  were deposited on its surface by precipitation from the black smokers, but also vast amounts of oceanic water entrapped within the sima.  As the sima plunges further into the mantle it is dewatered by the increasing pressure, and heated once again where the water assumes temperatures approaching 1,000 degrees Celsius. 

 Most subduction zones dip steeply under an adjoining plate where it reaches a depth where some of the lighter elements mainly aluminum and silicon become molten the further from the edge of the inland plate the composition of the magma changes from a mixture of basalt and granite called Andesite named after its type locality the Andes mountains.  The further landward the composition of the magma changes as it loses magnesium in relation to aluminum. 

Gold crystals on quartz.
Photo by Rob Lavinsky

Before any magma forms the heat and pressure have raised enough to dewater the subducted rock forming volatiles that are charged with chlorine, sulfur and various metal ions.  This is where most of the gold that was deposited on the surface of the oceanic crust by the action of black smokers is remobilized.  Some of it however is released into the environment as VMS deposits from the various types of magma.

The high temperatures reached in the volatiles causes the brine to become extremely corrosive that dissolves all the metal ions including gold.  Most of the metals however will combine with sulfur forming deposits of metal sulfides.  Other then some rare compounds the gold is deposited from the chlorine rich brine as the native metal, this is metallic gold that is deposited when the volatiles (hot water) reaches a temperature between 100 and 300 degrees Celsius depending on the chemical conditions of the rock where it is deposited.

Native gold is usually alloyed with other metals especially silver and copper.  Gold has an affinity for quartz and many gold deposits are composed of gold embedded in qiartz.  Gold also occurs in VMSs where gold is often found coating the interfaces between the crystal faces of the sulfides especially pyrite.

A considerable amount of gold can also occur in marble where it is disseminated through the body of the rock.  The gold deposits in the Carlin Trend in Nevada are this sort of deposit where the gold occurs in microscopic masses through the marble in such a small size they are only visible through an electron microscope.  

Sunday, January 23, 2011

Gold Occurrences in New York State

Although gold is known to occur in New York State a law dating back to the birth of the United States in 1776 dictates that any gold found in the state will remain the property of the State of New York. The effect of this law that is still on the books has acted as a damper on any efforts to find gold. Even if you were to find gold in your own backyard if you read the fine print on your deed you will find that gold does not belong to you but to the state. Efforts are now being made to change that law to date it is still in effect. Not only gold is affected by this law, but so is silver. Plainly the law says all gold and silver deposits found in New York will remain the property of the state. This law has been amended several times over the years allowing the finder of a gold deposit a period of several years to work his claim.

This is what gold looks like in the form of the Latrobe Nugget on display in the London Natural History Museum.
Photo by Gump Stump

Looking at a geological map of New York State it is easy to see that there are several environments in the state that are likely to contain both lode and placer gold. Probably the most likely place where you can find lode gold is in the Adirondacks, and the second most likely place is in the Hudson Highlands, and strangely enough right in New York City. These are areas in New York State where the bedrock is made up of crystalline rocks that may, or may not be the host for gold.

There is a lineation associated with the west bank of the Hudson River called Logan's line that marks the westernmost part of the Taconic orogeny. Anywhere to the east of this line it may be possible to find gold especially in the quartz veins found in the Slate belt of eastern New York along the border with New England.

This is how you pan for gold.  USGS

Two of the counties gathering attention are Columbia and Saratoga counties. Although the particulars of these deposits are not clear from examining the geology found in those counties it is apparent they are probably lode deposits.

Another potential source for gold is found in the conglomerate of both the Schwangunks and Catskills where it was weathered out of high mountain ranges that light to the east. The rocks that are found in the Schwangunks were deposited in the Queenstown Delta, and the conglomerates that are found in the Catskills were eroded from another later mountain range that light even further east. These ancient conglomerates could be the host of fossilized placer deposits similar to the Witwatersrand Reef in South Africa, the world's largest deposits of gold.

It may look like Manhattan, but there is likely to be gold under its streets.
Wikimedia Commons

There is likely to be gold found in placer deposits across the length and width of New York that were brought down by the action of continental glaciers in at least three glaciations in the past 1 million years. Immediately to the north of New York State lies the Abitibi Gold Belt of Québec and Ontario. This extends for over 500 miles from Wawa, Ontario to Val ‘Dor, Québec. The scouring action of the glacier removed any gold that was loose in the soil of these provinces and took it south to be deposited across the width of New York State.

Just to the north of the Pennsylvania State line is the terminal moraine of the last glacier. This is an area that would be no doubt be good for prospecting in the many streams and rivers that cut through the glacial deposits. The action of running water would tend to concentrate any gold that was deposited in this area by the melting of the glaciers.

The plunge pool under Niagara Falls probably contains gold if you can find a way to get it!
Wikimedia Commons

The other big terminal moraine in the state is Long Island, there is the possibility that a small amount of gold was brought down from New England by the glaciers forming deposits in the sand and gravel.

Although you may not get rich hunting for gold in New York State at least there is enough that may be found to at least see what it looks like. Maybe someday the state assembly will change the law about the possession of gold to where the average New Yorker will be able to keep any gold that he finds.  

Friday, January 21, 2011

Gold Occurrences in Connecticut

Gold has an early history in Connecticut where it was discovered and mined by the first governor ot the state, John Winthrop Jr. and one of his servants.  According to the story left by Winthrop they spent three weeks at Great Mountain near Cobalt, Connecticut mining, roasting, and assaying the ores from which they cast several gold rings.  Then he returned to his home in New London, Connecticut.  This was reported in the literary diary of Ezra Stiles the president of Yale University from 1778 to 1795.

Bedrock Geological Map of Connecticut
During the 1980s Prof. Anthony Philpotts and his geology class from the University of Connecticut discovered gold that assayed as high as 6 ounces per ton in the shaft of the old cobalt mine in Cobalt.  The discovery was made in the quartzite that overlies the cobalt deposit.  The assay work was done by the USGS.  The old time miners cut straight through the quartzite with no idea the gold was even present.

Dr. Philpotts got the credit for being the first discoverer of gold in Connecticut in modern times several years before that the author working with Newmont Mining that had a lab for assaying ores in Danbury, Connecticut found gold in the city of New Britain as an assessory mineral in a rock cut at the Columbus Avenue exit from Route 72.  The sample also contained several other metal sulfides including copper, lead, zinc and cadmium. The assay was performed at Newmont’s assay lab in Danbury.

Gold in Quartz, this is similar to a specimen that came from Leadmine Brook in Thomaston, Connecticut
Photo by Rob Lavinsky 

In the period starting about 1968 to present the author has sampled most of the streams in western Connecticut and is found virtually all of them contain gold. The quantity of gold discovered in the streams is small, and not enough to make a living at, but they do contain enough gold so you can see what it looks like.

Winthrop's alleged success has caused virtually every part of the state of Connecticut to be explored and dug into by some would-be prospector who is absolutely confident he would find a rich deposit of gold. One of the many traditions of course concerns a lost mine, but a very rich deposit of gold in the town of Ridgefield. On Mt. Carmel in Ridgefield there is an excavation that reportedly has had gold taken from it, and our Mt. Sanford in the same town there is a man who swears he has a gold mine in his backyard.

In at least two or three cases there have been companies formed that sold stock, but apparently no gold was ever found. In 1886 one prospector by the name of August Prehn picked up a piece of quartz on Mill Road in West Haven upon which he got an analysis that showed traces of gold. On the strength of this report Mr. Prehn’s son quit his job in Pittsburg and returned home where he organized a mining company that sank three shafts.. The stories differ about the amount of ore those taken from this mine, or even if any was taken at all. The only thing the townspeople can agree on was that after a short time all mining efforts at the mine were abandoned.

This is interesting because on the bedrock geological map of Connecticut this area is mapped as having contained greenstone that is considered by many geologists to be the source for hydrothermal gold deposits where the gold is leached from the stone. According to the New Haven register there was another gold rush that occurred in West Haven during the 1930s.

Most of the gold bearing rocks in Connecticut are discovered to the west of the Connecticut River an area in which there are abundant crystalline rock deposits many of which may be the source of gold. There is gold to be found in Connecticut, but it appears that any placer gold is going to be sparse. It is also obvious that although gold is present there probably isn't enough to make anyone rich, let alone make a living.

Thursday, January 20, 2011

Gold Occurrences in Rhode Island

Gold occurrences in Rhode Island are not the subject of many reports, however there is the story of the Durfee Hill Gold Mine in Glocester, Rhode Island where there are reports of the remains of a stamping mill and cyanide vats on the site.  There are also some mine shafts that are sunk into the ground nearby.  There are no apparent reports of gold in quartz veins. There are however, reports of gold with pyrite in the quartz veins. The reports of the latter is from Kent County, to the west of Warwick.

Gold bearing pyrite crystals in quartz.
Photo by Rob Lavinsky

Gold that occurs in Rhode Island in three different types of deposits:

One type of gold is found in veins of hydrothermal deposits where the gold often occurs as the native metal in quartz veins.

The second type of gold is often found in his placer deposits in sand and gravel on the beds of streams or on beaches fronting on the ocean. Gold is often panned from this type of deposits by taking advantage of its great density in relation to other minerals. Gold is 19.3 times as dense as water and most of the minerals that occurs with our only three times as dense as water. Placer gold can be found in virtually any stream or river in the world in quantities large enough to see what it looks like.

Gold in quartz.
Photo by Rob Lavinsky

In a 1927 issue of the American Mineralogist by Lloyd Fisher and Charles G. Doll of Brown University in volume 12, pages 427 to 436 you can find a listing of the different minerals that are found in the state of Rhode Island.

This is what they said about the area around Durfee Hill, “Glocester (Durfee Hill) epidote, molybdenite, pyrite and phyrottite are present.

The third type of deposits are found in generally associated with pyrite and other metal sulfides where the gold actually appears as a thin film between the crystals of sulfide. 

Another area where gold was then reported in the past is around Johnstown where there are also some old mine workings were a dibase dike cuts across the granites and schists. This is another area that still has old cyanide vats and sluice boxes. When the local chemists reports that the locality has shown a trace of platinum group metals in the mine tailings.

Finally there has been Gold reported at the old South Foster gold mine locality where gold was produced mainly from pyriteferous quartz veins.  There are said to be still visible at this locality four open pits that are now filled with water along with the ruins of a large stamp mill.

One of the areas in Newport, Rhode Island, Purgatory Cliffs, has attracted the attention of the author because the cliffs are made out of a quartz pebble conglomerate with crystals of magnetite in the binding material between the pebbles. There is often an association between gold and magnetite. Another area is found in the black sands of the beaches in southern Rhode Island west of Narragansett Bay.

Although these last places are strictly speculative the geology is right for finding gold, and as far as that goes the entire set of rocks along the western side of Rhode Island where borders with Connecticut is another area that geologically is a good place to search for gold especially in placer deposits in the streambeds of the area.

Wednesday, January 19, 2011

Gold Occurrences in Alaska

Gold is found throughout Alaska, and the resources are as vast as the land itself. One of the prominent features found in Alaska is the Tintina Gold Province (TGP) an arching curve that extends all the way from northern British Columbia, the southwestern part of the Yukon Territory and crosses the entire state of Alaska where it finally vanishes into the sea northwest of Anchorage. This gold belt has produced several gold rushes over the years probably the most famous is the Klondike Gold Rush that occurred in the late 1890s.

A gold dredge working on the TGP
Photo by Chris Lot

The TGP covers roughly 150,000 km² that is bounded on the north by the Kaltag Tintina fault and on the south by the Farewell-Denali fault. Geologically it could be considered a suture zone where one tectonic plate collided with another one. Throughout most of this vast area you can only find a few roads one of which is the famous Alcan Highway that goes to Fairbanks. The apex of the TGP arc is just about centered on Fairbanks, Alaska. Altogether the TGP is one of largest gold provinces in the world at 1200 km long and about 200 km wide.

The Tintina Gold Belt superimposed on a Landsat image.   USGS

The regional climate that is associated with the TGP is generally subarctic that includes several different physiographic regions and ecoregions like that Yukon-Tanana upland, the Yukon River low lands and the Kuskokwin Mountains.

Geologically Alaska is made up of several different terranes with the Tintina gold belt being only one of many. Although the TGP is the largest one in Alaska gold can be found throughout the state. Most of the Gold that has been recovered in the TGP to date has been placer gold, but new methods of mining and metallurgy have allowed some previously known deposits to be brought online.

Virtually all of the known gold deposits in the state have already been staked, but it is still possible in the state of Alaska to buy or lease a claim. There is a lot of information about doing this on the Internet. We put into our web browser, “Mining claims for sale in Alaska” and had more than 9,600,000 hits.

In addition to the gold deposits found in the TGP that also contains many other deposits of Volcanogenic Massive Sulfide (VGM) minerals. Some of the other metals that are produced in the TGP include copper, lead, zinc and tungsten.

Tuesday, January 18, 2011

Have Gold Prices gone into a Slump?

A 250 kilogram gold bar.

In December 2010 gold prices hit an all-time high of $1432.50 in New York, but by January 14, 2011 the price of gold had sunk to $1361.80 per ounce, a decrease of almost 5 percent. Right now gold prices are in this slump that coincides with the expectations of many investors that the economy is slowly recovering in the United States and the European Union. The question is now being asked is, are investors gaining more confidence in the economy by taking their money out of gold and putting it into more speculative ventures. The other question they are asking themselves is this only a small correction or does it indicate a continuing upward trend in the economy?

According to Bloomberg during the second week of January 2011 the price of gold fell on the New York Stock Exchange to its lowest settlement price in seven weeks. This was fueled by speculation that the leaders of the European Union would stabilize economy thereby ending the appeal of gold as a safe haven.

One economist, Dennis Gartman, was quoted as saying that the price of gold was now “toppy” recommending that investors cut their holdings by about one third saying that “Gold has run its course for a while.”

Right now gold and silver may not be the best investment in the world, but in the long run the price for both of these metals looks bright it is expected to rise to even higher levels. Many producers of gold expect to see the price topped $2000 per ounce.

Monday, January 17, 2011

Wild Animals and the Gold Prospector

Most gold prospecting takes place in the wilds meaning that you are likely to encounter wild animals as you are prospecting.  Most wild animals will go out of the way to avoid you, but always keep in mind that any wild animal is not your friend.  The truth is any large animal can be dangerous, and many of them look at you as something for lunch.  Other animals have venomous bites including some kinds of snakes and lizards.

A rattle snake in his natural habitat. 

The encounter Nancy Twinkie had with a large water snake gave her a good scare, but under the circumstances had that snake been venomous that encounter could have resulted in a tragedy.  If a snake bite doesn’t kill you they are extremely painful, disfiguring and take a long time to heal.

You are apt to encounter venomous snakes near bodies of water, rocky places or any other place that offers concealment like old mines.  Years ago we had a lease on a mine in the central Berkshires of Massachusetts that had so many venomous snakes (rattlesnakes) that before you could do any work in the mine first you had to clear the snakes.  On another occasion we were prospecting in an old mine dump when my partner encountered a whole den of venomous snakes.  He wasn’t bit, but he sure moved fast!

A whitetail buck during rutting season.
Photo by Clinton and Charles Robertson

Snakes aren’t the only dangerous animal you are likely to meet in the wilds.  One of the most dangerous is any member of the deer family.  The members of the deer family are not the noble animal depicted in fiction, in reality they can be outright dangerous especially during the rutting season when the bucks will charge anything that moves.  The bull moose, a member of the deer family, have even known to charge locomotives during the rutting season.

A bull moose during rutting season.

One of the most dangerous situations we ever faced in the wilds is a pack of feral dogs.  These are somebody’s pet dogs that have gone wild.  Because they are familiar with people they do not fear man, and believe me a pack of these dogs can be absolutely dangerous. 

Feral Dogs.

When I was an active field geologist we had two encounters with bears, one of these encounters was with a family of four bears a female, a yearling and two cubs.  You don’t want anything to do with a female bear with cubs.  The other encounter was being stalked by a polar bear.  Polar bears look upon humans as some sort of seal their natural food, and this one was thinking about lunch.  We were forced to kill the bear when he charged us.

A polar bear similar to the one that stalked us while prospecting in the Arctic.

The strangest encounter you can have with an animal is with a large bird.  One morning I was walking my dog in a swampy area when I came around a clump of bushes and had en eyeball to eyeball encounter with a great blue heron.  These birds have a long sharp bill that they use to catch fish or to defend them selves usually aiming at their attacker’s eyes.

A great blue heron
photo by Ken Thomas

Wild animals aren’t your friends, but by exercising due caution you can usually keep most of them away by being noisy, and even whistling.  Some people even go to wearing bells to ward off most animals.  Probably the best thing to do if there are large carnivorous animals in an area is simply to avoid going into the locality. 

A mountain lion there are several reports of fatalities every year from these big cats in the United States

When going into any unfamiliar area the best policy is to exercise due diligence!

Sunday, January 16, 2011

Nancy Twinkie and the Giant Jumbo Watersnake

You might wonder what on earth water snakes have to do with prospecting for gold; well they live around water in lakes and streams, so doe’s placer gold.  The watersnake that is found in the north isn’t poisonous unlike the southern water moccasin that is also called the cottenmouth because of the white lining in their mouths.  Even though watersnakes aren’t poisonous about the last thing you want to do is stumble on one of these critters when you don’t expect them.

A northern water snake

To my surprise I found that Nancy Twinkie lived just a little over a mile from where my house was, so on the following Saturday morning I picked her up at her house to take off on a day of prospecting in the Berkshires of Massachusetts.  After stopping for breakfast at the Farmington River Country Store in Otis, We continued north to a stream in Chester, Massachusetts for our first stop.  This is a small stream right alongside US RT. 20 near the mineral collecting site associated with the old Chester Emery Mines. 

After parking the car on the south side of the stream we unpacked out gear; I brought along an extra shovel and gold pan for Nancy.  It was really good to talk with her without having a whole thundering herd tagging along.  No cameramen, no producers, friends, wellwishers or passersby were present this morning.

This is a mountain stream similar to where we were prospecting. 

After teaching Nancy the ropes of gold panning she wandered off a little ways downstream to try her luck on her own; meanwhile I went about my own panning when suddenly the most Godawful scream you ever heard split the air.

I jumped up to see what all the whooping and hollering was about when Nancy flew into my arms.  Over her should I could see a large watersnake about five feet long slither into the stream and head downstream as fast as he could.  Apparently he couldn’t stand all the noise either.

After a while Nancy calmed down as I explained that watersnakes are occasionally encountered near water, and although they can scare the devil out of you they aren’t really dangerous.

That ended the gold prospecting for that day, so we climbed the mountain to look over some of the old mine dumps from one of the emery mines.  The mines are located virtually under the powerline that crosses Rt. 20 just west of the center of Chester.  There are actually six of these old mines, but only one on the south side of the stream.

This is the sort of device that was made from the emery from the Chester, MA emery mines.

The dumps yield several interesting minerals including corundum, chromite, emery and margarite.  It was from the chromite produced from these mines that some chemist in developed “potassium chromate” that changed the tanning industry literally overnight in the late 1800s with the introduction of the chrome tanning process

A leather tanning barrel in a museum
Photo by Joan Grifols

If you actually climb up to where the mine is located be very careful because the thing is like a giant ant lion nest; once you get onto the funnel shaped slope leading to the mine entrance it suddenly  becomes a real chore to get out of the pit.  For the amount of ore the mine produced it is apparent that when the mine was active there was some kind of works that made the mine accessible.  Today any such works has long vanished leaving a slope that even trapped me taking over an hour to climb out of this ant trap.  Be careful!

The Geologic Framework of a Gold Bearing Suture Zone: Part One

The estimated abundance of gold in the earth’s crust is 4x10-3 milligram per kilogram meaning this is the average amount of gold found in every kilogram found in the earth’s crust.  Although gold can be found virtually every place on earth the trick is to find it where it has been concentrated by geological processes to make it profitable to mine.  The necessary conditions are found in several places on earth that within reason have similar conditions that are called by several different names.  One of the most common names is “Gold Belt” another is “Gold Province.”  Names like these are used to define primary deposits of gold that have been deposited by the action of hot salt brines that are in excess of 100o C that deposit their dissolved gold either when its temperature drops below a certain point, or encounters conditions that cause the chemical precipitation of gold by reacting with other rocks.

A map showing modern tectonic plates.

Gold is also deposited when it has been eroded from the rock where it was primarily deposited as detritus in the beds of streams or a similar environment.  In this form gold is called “Placer or alluvial gold.”  Aside from being found in stream sediments it can also be found in sandstone or conglomerate that are really nothing other then fossilized sedimentary deposits.  The largest known deposit of gold is in one of these fossilized conglomerate deposits, the Witwatersrand in South Africa.  The mines here are the deepest on earth some of them are in excess of 13,000 feet deep.

Tectonic Plate boundaries.

Primary gold deposits accompanied by placer deposits are found mainly in suture zones where one tectonic plate collides with another.  In some cases the oceanic plate is subducted beneath a continent with little affect.  In other cases two continental land masses collide throwing up ranges of great mountains.  There are several examples of this on earth today.  The grand daddy of all mountain ranges caused by such a collision is the Himalayas caused by the collision of two continents, the Asian and the Indian plates.  Between these plates there used to be an ocean called the Tethys Sea that vanished when the collision occurred.  Other examples of similar mountain ranges can be found all over the face of the earth, some of the more recent are: the Appalachians, the Alps, the Andes, the Rockies to name a few of many.

A suture zone is depicted in this series of charts.

Because of the nature of this subject it will require several separate articles to treat it as it should be.  The next article in this series will explain how mineral deposits are emplaced in a suture zone including gold.

Saturday, January 15, 2011

Gold Occurrences in Massachusetts

Most of the gold that is found in the state of Massachusetts lies to the west of the Connecticut River on the east slopes of the Berkshires. Although many people think that the gold in Massachusetts was brought down by the glacier from Canada that is not necessarily so although some of it may be of Canadian origin. The eastern flank of the Berkshires east of the contact between Hoosac formation and the Rowe schist is included in the Iapetus suture zone that also includes the rest of the Northern Appalachian gold belt. Although it is rather sparse lode gold has been found in Massachusetts in several places, but for the average gold seeker placer gold is far more common. Just about any stream draining the East Flank of the Berkshire Mountains contains placer gold.

This is a view of the Berkshire Mountains in the wintertime.

Way back in the 1970s one of our clients for environmental consulting was a large vacation community that is located in Otis, Massachusetts. One afternoon the developer of this community called me on the phone and asked me if I could identify gold. I told him I would have to see the sample, so he said come on up and have a look. When we arrived at his office one of his excavating contractors was there with a piece of quartz with plates of gold literally hanging out of the thing. A simple test for gold was performed with the end of the needle to see if the gold was flexible because any other mineral resembling gold isn't.

The contractor told me he had been working on a construction project further north in Beckett, Massachusetts, and had buried about 20 tons of this gold bearing quartz under several feet of fill because he thought it was fools gold. By the looks of the sample he showed me it would appear he buried several hundred dollars worth of gold under that pile of fill.

This is the famous Bridge of Flowers spanning the Deerfield River at Shelburn Falls Massachusetts.

Although finding lode gold is usually beyond the capabilities of the Small-scale miner because it often takes millions of dollars to develop a hard rock gold mine. Placer gold is well within the reach of the small-scale miner. There are plenty of opportunities to be had in the Berkshires for the recovery of gold in virtually every stream that is east of the contact between Hoosac formation and the Rowe schist.

Some of the more notable gold panning streams that are found in the Berkshires are the Deerfield River, Mill River and the Westfield River. During the period of time in the 1970s and 80s we panned these streams and did find some gold, You won't get rich panning for gold in Massachusetts, but at least you'll find enough to know what it looks like.

Friday, January 14, 2011

Gold Occurrences in Vermont

Did you ever know that Calvin Coolidge the 30th president of the United States as a young man was a gold miner in Plymouth, Vermont where he was born. Virtually all the rivers and streams on the east flank of the Green Mountains are gold bearing. This gold belt crosses the Connecticut River as part of the Ammonoosuc gold belt of New Hampshire and extends northwards into Québec. This is part of a larger gold belt found in the northern Appalachians that extends all the way from Staten Island, New York to Baie Verte on the north coast of Newfoundland. On the landward side there is a continuous thrust fault that goes by many names but is continuous from one end to the other.

In this case however we are only considering the gold bearing areas in the state of Vermont. These are found in the eastern flank of the Green Mountains in the so-called Iapetus Suture Zone an area that is bounded on its west side by large intrusions granite. On its Eastside it is bounded by the Connecticut River. Virtually anywhere in this zone It is possible to find both lode and the placer gold.

The Waits River one of the many goldbearing streams of Vermont.

Even though the idea of finding gold causes us to have dreams of fabulous wealth in Vermont although there is gold there is not enough that has been discovered so far to make anyone wealthy. Several years ago there were unproven rumors about someone finding a gold pocket in the Williams River that produced over $2800 worth of gold in one afternoon.

Aside from gold there are also many occurrences of sulfide minerals in Vermont lying within the Connecticut Valley -- Gaspé Synclinorium and the Bronson Hill Anticlorium as well as the Appalachian province of Stratabound massive sulfide minerals. There are also isolated occurrences that are associated with the Green Mountain Anticlinorium Tectonic Province.

While a great many of the soleplate minerals have been discovered in Vermont that include lead, zinc, copper, molybdenum and arsenopyrite, copper was the only sulfide mineral that was mined on a large scale. Most of these sulfides contain gold as a byproduct.

At the present time, other than gold, no other metallic minerals are being mined in Vermont at the present time. The copper sulfide ore was originally discovered in Orange County as early as 1793, but it took another four years in the early 1830s before was finally mined. Until the discovery of copper on the Keweenah Peninsula of Michigan in 1846 Vermont was the largest producer of copper in the United States.

To this day the Orange County Mining District is a scar on the landscape. The site of the mine is at present listed on CERCLIS the EPA's database showing potential hazardous waste sites that will eventually be remediated under the Superfund program.

The first reports of gold in Vermont surfaced in 1845 when the State Geologist C.B. Adam's in his First Annual Report on the Geology of Vermont reported finding gold in the town of Somerset, Vermont.

It was four years later when the California gold rush caused many Vermonters to search for gold in California. By the mid-1850s many of these gold seekers had returned home. One of these 49ers by the name of Capt. Abial Slayton had struck it rich on his California gold claim. When he returned to Vermont in 1855 he went on to discover gold in what was then Hull's Brook that has since been renamed Gold Brook in Stowe. At the time of his discovery Slayton set up a sluicing operation that employed several people. Although this gold discovery never produced the amount of gold be found in California it did produce enough so that in 1887 the builders of the Mount Mansfield Electric Railroad drove the last spike that was coated with some of Slayton's gold.

An old fashioned gold pan used by the 49ers.
Photo by Nate Culi

In 1854, a mine containing gold, silver, lead and copper was opened in Bridgewater, Vermont. In this mine called was found as small irregular grains in quartz. It was noted in 1867 by Dr. C. T. Jackson that the so-called great Appalachian gold belt passed through both Plymouth and Bridgewater.

By the early 1900s even though gold was present in Vermont it was determined that it didn't occur in commercial quantities. There had been gold bearing rocks discovered in Plymouth and Bridgewater that were mined only it cost more to mind the metal than it was worth. By that time it was determined that it is useless to spend time and money trying to find a fortune in gold mining in Vermont.

It was the placer deposits that were found in the Plymouth area around 1855 that Calvin Coolidge later worked for gold when he was a young man. Even though there are plenty of indications that no one will get rich mining gold in Vermont, gold hunters are still out there looking for gold during the summer months when many people converge on the gold bearing streams in the state trying to recover “free gold” from stream gravels found in the beds of rivers and streams throughout the state.

Wednesday, January 12, 2011

The Ammonoosuc Gold Belt in New Hampshire:

The Ammonoosuc Gold Belt in New Hampshire is only a part of a much larger gold bearing district that extends out of southeastern Vermont and up the Connecticut River to New Hampshire and Québec even further north. In New Hampshire this belt contains the highest potential in the entire state where important discoveries of gold and other metals may be found.

This gold bearing district is closely associated with the Iapetus Suture Zone caused by the closing of the Iapetus Ocean hundreds of millions of years ago. This suture zone is traceable all away from Staten Island New York across the Atlantic Ocean to the mountains of northern Norway. Although this is one of the major suture zones on earth it has been little explored by miners.

Rocks found in this belt are metamorphic in origin for many of them were originally deposited as volcanics that could be endowed with gold. This zone is now the host of the most intense placer gold recovery in the state that in recent years has taken place in the sand and gravel deposits throughout the district.
The Ammonoosuc River at the Littleton Grist Mill during the Winter
Photo by Captain Tucker

The rocks found in the White Mountains and other genetically associated rocks to the South like those within the Patuckaway Mountains are also considered to be favorable for gold prospecting. Throughout the state the potential for gold being found along faults is high especially in those that have been acted upon by hydrothermal waters were quartz has been deposited in veins as so-called bull quartz. Bull quartz is a particular milky variety of crystalline quartz in veins that often has gold deposited on the interfaces of its crystals.

Gold has been found in many of the streams of northern and western New Hampshire included in this partial list:

Town Stream
Benton Tunnel Brook
Lincoln Notch Brook
Lisbon Salmon hole Brook
Wild Ammonoosuc River
Ammonoosuc River below the town of Bath

Northern Coos County

Indian Stream
Perry Stream
Dead Diamond River
Swift diamond River

Because of the potential damage that they can cause all gold panners should try to keep the disturbance of the stream beds of the low level of disturbance.

A great deal of information about gold found in New Hampshire is available from the geological survey of the state that is located in Concord. Another source of information is often to be found in old town histories.

Gold Occurrences in New Hampshire

Too many of us the very thought of gold mining produces visions of the California gold rush or trekking into the Klondike during the Klondike Gold Rush. Our thoughts immediately bring up the picture of some grizzled old prospector with a donkey looking for gold in some far-off desert, or a frozen waste in some icebound part of the far North. To everyone's surprise gold is not unknown in the Granite State of New Hampshire.

When some New Hampshire miners return from the California gold rush they went poking around in the hills and mountains of their native state, and they discovered that both lode and placer gold could be found in them thar hills. Most of gold from the New Hampshire is located in Grafton County where it occurs as both veins in the country rock and is placer deposits in the rivers and streams of the county. Gold is found in many different geological environments ranging all the way from igneous rocks, metamorphic rocks, sedimentary rocks and then detritus such as sand and gravel or any other soil that is found in New Hampshire.         

A postage stamp of the Old Man of the Mountains New Hampshire's state symbol that used to be in Franconia Notch
Gold is considered a noble metal because it resists corrosion and any other kind of chemical weathering it is only dissolved by a mixture of nitric acid and hydrochloric acid that is called aqua regia or in solutions of alkaline metal cyanide usually in the form of potassium cyanide. It also combines with mercury to form a gold/mercury amalgamate. Many of its unique properties are taken advantage of in the process of refining gold. It is also the same standoff property from other elements that causes gold to be found in its native form sometimes almost pure, and at other times alloyed with silver in a pale brassy colored metal called electrum.

Gold Panning in New Hampshire  
Photo by Alan Souter

Gold is extremely malleable so that it can be beaten into thin sheets only a few atoms thick that are called goldleaf that is used for gilding many objects of art. It is the same property that forms gold nuggets it's in streams when the metal is being transported by water.

Gold is found in lode deposits where it is held loosely in the intracrystalline spaces in quartz veins as a special alloy with silver that is called electrum, As disseminated deposits like the deposits in Nevada's Carlin Trend where the gold is so fine it can only be seen with an electron microscope. The metal is also found is placer deposits in the beds of streams, or beach deposits and sometimes in stratified glacial drift.

Gold is one of the metals that tends to be fractionated from late stage hydrothermal fluids that form during the cooling of igneous rocks such as granite. In rock metamorphism gold tends to be quite mobile especially when the rocks hold an abundant amount of brine, usually a salty brine.

The Ammonoosuc River spanned by a covered bridge at Bath, New Hampshire

Gold is usually associated with granitic rocks, but also with those rocks that are known serpentinite that theoretically are fragments of rock from the ocean bottom that were originally basalt that have been altered into serpentine by the process of metamorphism. Another name for serpentinite is greenstone and it is assumed that greenstone contained gold that was leached out by the action of salt brine and deposited in quartz veins. One of the largest greenstone belts in the world is the Abitibi Gold Belt found in Québec and Ontario, Canada.

For the most part now that rocks that are now abundant in the state are usually found associated with the granitic rocks of the White Mountains. It is estimated that about 50% of the rocks in the state are metamorphic that in part are derived from rocks that were originally of volcanic origin.

Mount Washington from Bretton Woods
Photo by W. Woods

In New Hampshire most groundwater contains trace amounts of gold that is usually less than 1 ppb for the most part are of scientific interest only but can be used for geochemical exploration that is often be used for locating lode deposits of gold and other metals.
Although gold can be found widely dispersed across the entire state of New Hampshire to rocks that are of the most interest to the mineral exploration companies are those in which gold is finely disseminated in deposits similar to the Carling Trend of Nevada. Modern gold exploration is today centered on low-grade, large volume deposits than on high-grade deposits such as those found in quartz veins.

Such lode deposits however are an important source of specimens for the rock and mineral collectors that are found throughout the state. Placer gold is Gold that has been weathered out of rocks and has been transported by water and redeposited in the bed of streams. Placer deposits are often found on beaches or offshore marine sediments especially when they are near the mouths of rivers and streams entering the sea.

It would be nice if this gold was found in New Hampshire, but it came from Alaska
Photo by Alaskan Miner

In the state of New Hampshire recreational gold panners or the operators of sluice or rocker boxes and portable dredges are not regulated by New Hampshire statutes. However large-scale dredging and similar operations are regulated by the state understand statues RSA 482 -- A and RSA 485 -- a: 17 because of their potential for causing environmental damage. In all cases it is necessary to have landowner’s permission before commencing any gold covering operations on private property, and if you are planning any large-scale operations unit better contact the state first for the latest regulations.

You can get detailed information about permitting from:
New Hampshire wetlands Bureau
P.O. Box 95, Hazen Drive
Concord New, Hampshire 03302 -- 0095
Phone (603) 271 – 2147

The use of power equipment is not permitted in the White Mountains National Forest for the recovery of gold that includes sluice boxes, rocker boxes and dredges, but recreational gold panning is allowed.

Even though gold mining has never been done on a commercial scale in New Hampshire mining interest dates all the way back to colonial times with the possibility of a major gold find being found within the context of modern gold genetic models similar to the Carlin trend in Nevada.

There have been found in New Hampshire many anomalous occurrences of gold that were well documented by the mid-19th century. Many of these deposits were found by 49ers returning home from the California Gold Fields that realized many of the local rocks were similar to those that were found in the California Gold Fields. The first deposits that were found by these miners were along the Ammonoosuc River in Grafton County where even today it is possible to pan for gold. By 1864 there were several small mines that were open supporting 2 operations that produced about $50,000 worth of gold that at the time there was valued at $20 per ounce. This gold was shipped to the Philadelphia Mint before economic circumstances closed the mines.

A bit later in 1878 a smaller amount of gold that was shipped to the Philadelphia Mint that was produced at Diamond Ledge mine in Ossipee. The richest area in the state is centered on the Ammonoosuc district where it is found in veins of sulfide minerals such as pyrite for his free gold that is the positive in quartz veins, or dispersed in sheared chloritic schist.

The Ammonoosuc Gold District is centered on the towns of Lyman, Monroe and Bath. It can also be found in southwestern little plum, northwestern Landaff and Western Lisbon extending north to the Connecticut Lakes. Any of the streams running westward to the Connecticut River in this district are all likely to be gold bearing.

Monday, January 10, 2011

The Hollon GoldMaker for Rapid Gold Recovery

The latest entry into the tools available to small scale gold miners is the Hollon GoldMaker. The Gold- Maker is an extremely efficient and highly portable device for working in placer gold deposits. This is not a toy, nor is it a gimmick it will go is designed for producing the largest amount of gold as fast as possible for a couple of guys or gals armed with shovels. The maker says, “if you can shovel into the top, you can make gold.”

The Hollon GoldMaker setup for action.


The Gold maker only weighs 32 pounds with its legs included. It has a unique molded spray bar supplying water to the Gold maker that has a built in slope that is capable of producing more Gold. This will build device was invented, tested and built by miners that love gold mining.

The Gold maker only requires 20 gallons of water to operate, it is equipped with a scalper allowing for quick field testing for gold and other valuable minerals. At the bottom of the Gold maker there is 11 1/4 inch wide true or that easily fits into a 5 gallon plastic bucket for a quick clean-up.

Another view of the Hollon GoldMaker 

 Accessories for the Gold Maker:

Gold maker comes equipped with a 2 inch suction nozzle including 15 feet of either one or two inch in diameter and a 2 inch suction nozzle with attachments.
There are also a set of settings and legs so that you can turn your Gold maker high bank or into the 2 inch suction dredge high bank or combo.

The Hollon GoldMaker in use being loaded with stream gravel.

How what works:

All you have to do to use the Hollon Gold maker is to show will some gold bearing gravel into the top where it is washed by water from the spray bar. If there is any material larger than three quarters of an inch is classified and exited by the top classifier, but is sometimes called a grizzly. By exiting the discarded material near the top of the Gold banker close your discard pile to grow without trying to crawl back into the machine immediately or fouling the lower sluice box.

In the next step the smaller material passes through 8 second 3/16 inch minus classifier to enter the recovery drawer. This recovery drawer has several features that were designed especially for trapping the finest gold that includes two boil recovery areas having unique scallops that were designed to put the finest gold further up the hill, and at the back of the boil. This design means it is less likely to migrate down through the riffle system to eventually run out of the bottom of the machine.

The Top of the GoldMaker showing the grizzly for removing large stones.

The Gold banker also features a scalper area which can be quickly cleaned and panned to test a theory that you are mining in an area that is Really productive. After two or three hours of operation, all you have to do is simply remove the drawer and recover your Gold.

If you are worried about the material that measures between 3/4 inch and 3/16 inch that may contain potential gold nuggets. In the GoldMaker this material slides down to the second classifier where it is reloaded into the sluice box below the find recovery drawer allowing the nuggets to be recovered without them or the other medium material mixing with and fouling the fine gold recovery.

The two inch suction dredge used in conjunction with the GoldMaker.

Throughout the entire 34 inch gold recovery system the whole thing is laced with an expanded style of riffles and trips designed to catch gold. Riffles used in virtually all the other gold recovery systems are not able to catch the finest gold alone because the action of water and materials of the sluice box as well as vibrations caused from shoveling along with the rocks rattling around in the system as they move down and out will eventually allow many small gold flakes to slowly migrate out one step at a time. The unique system of boil recovery that is used in the Gold Maker is one of its most important features. Until you have used the Gold maker system that catches even the finest gold particles in quantity, you will does not know what you have been missing!


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