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Friday, March 30, 2012

John Carter on Martian Gold Mining

Mars from the Hubble Telescope   NASA

It may be a long time before we have prospector’s boots on ground on Mars, but we already know the Red Planet has gold deposits.  Gold and other valuable minerals on Mars will be associated with such geologic features as volcanoes, lava flows and impact craters.  Because the Red Planet has a totally different history, atmosphere and chemistry then Earth it is certain that many of the minerals found on Mars will be different then minerals found on Earth.  Another thing that is certain it will be a long time before any of these minerals and ores will find their way back to Earth.

Since all the elements in the universe other than hydrogen and helium are the results of atomic fusion that has taken place inside of stars and is a byproduct of supernova's gold can be found throughout the universe as a universal substance. You might consider gold and the other elements as leftovers from the formation of a supernova.

Olympus Mons the largest volcano on Mars and the largest known volcano in the Solar Ststem   NASA

Future prospectors on Mars are likely to find valuable mineral deposits in some usual locations according to planetary scientists that have been studying different ways to valuable deposits of metal ores can be concentrated on the red planet Mars as well as all the other planets in the universe.

The only environment that we have observed so far are those found on Earth or surface waters, ground waters and even chemicals left by lifeforms have played a major role in leaching, concentrating and depositing different kinds of valuable metal deposits including gold, silver, nickel, copper, iron and all the rest of the valuable minerals.

Victoria Crater, Mars showing its distinct scalloped edge caused by erosion.  This is a typical impact crater caused by a large asteroid that collided with Mars.  Both volcanoes and these features would be prime targets for prospecting.  Notice the large field of sand dunes in the center of the crater.   NASA

At present there is no surface water visible on Mars but there is plenty of evidence visible themselves this used to be running water across the surface of Mars. This fact indicates that there is ample evidence to support the idea of finding place or deposits on the surface of Mars where gold and other metals have been concentrated by the action of running water as well as wind. Other than these placer deposits question is raised where else does the starving prospector look for gold and other valuable metals on Mars.

Valleys and canyons on the surface of Mars as seen from the orbiter HiRise   NASA

According to planetary scientist Michael West of the Australian national University in Canberra and the Mars Institute is desirable minerals would be found around volcanoes and impact craters. One of the great differences in prospecting on Mars versus the planet Earth is that on Mars the planet is so cold that even groundwater is turned to ice as permafrost so that it functions little more than as another mineral in the ground.

Yes, there is gold to be found on Mars but don't count on putting any evidence of it in Fort Knox for a few more years at least.

Friday, March 23, 2012

Gold Occurrences in Chile

Coat of Arms of Chile
by B!mbo

Whenever anyone thinks of Chile they immediately think of copper since it is the largest producer of copper in the world, but many of the copper deposits have gold and silver as trace metals.  A recent statement by the Chilean Copper Commission (Cochilco) says their country’s production of gold could triple by 2015 making the country one of the top producers in the world.  Currently Chile’s gold production is pegged at 39.2 tonnes, however new developments and expansions of existing mines could cause output to swell to 103 tonnes by 2015.  This figure may be an underestimation as there are other gold mining projects waiting in the background.  Most of the gold produced in Chile comes from the production of copper as a byproduct.

There are several mining companies involved with this surge in gold production with the most notable being Barrick with its Pascua Lama project.  This does not include several other gold mining projects that are waiting in the wings.  Recent discoveries of gold/copper mineralization have been found in the high Andes that have become viable because of the high rise in gold and copper prices.  The biggest hurdle facing miners is the lack of or shortage of capital for developing these gold finds that sometimes can cost billions of dollars to get them into production.

Most of these projects in the high Andes are found above the 4,000 meter line making them difficult to mine as operations are hard on both personnel and equipment.  Some of these projects are centered on banded quartz projects carrying in places high anomalies of gold.  Other projects are to be found in gold bearing porphyry that has a lower gold content, but because of the vast volumes of rock present high tonnage, low grade projects.  At present the main target of the explorers is at La Falda that is a near-surface porphyry having associated epithermal gold-silver. 

Chile is not as famous for gold production then either Mexico or Peru exploration of the country by the Spaniards was financed with the placer gold that was discovered there.  In 1810 an the eve of its independence Chile was producing as much gold as Mexico and Peru combined.  In the 16th century from the founding of Santiago in 1541 gold from placer deposits mainly in the southern part of the country produced up to 2 tonnes of gold annually. This mining came to an abrupt end when the Spaniards were evicted by the local Indians.

A second cycle of gold production started at about 1740 that were mainly based on vein mining.  The gold was recovered using trapiches and mercury to recover the gold.  This production peaked with the production of 3 tonnes in 1810.  There were several areas that were producing gold with the most prominent being located at Andacollo and other areas.  Gold production in all areas declined during the War of Independence that was finally reached in 1823.

Thursday, March 22, 2012

Gold Occurrences in Peru

Coat of Arms of Peru
By Hunsun

Located high in the Andes of Peru, Newmont operates the largest gold mine in South America, the Yanacocha mine.  This mine has three active pits with the production exceeding 26 million ounces of gold.  The Yanacocha mine high in the Andes opened in 1993 with Newmont owns 56% of the mine with the balance held by Cia de Minas Buenaventura SA, this is Peru’s largest producer of precious metals.  This year, 2012, the mine is expected to produce 1.5 million ounces.

Another mine operated by Goldfields is the Cerro Corona mine a large open pit mine located in the highest part of the western Cordillera of the Andes in the northern part of Peru contains a copper-gold deposit estimated to contain about 8.7 million ounces of gold equivalent.  The concentrate produced by the flotation process leaves Peru from the port of Salaverry for smelters in Japan, Korea and Europe.  There are several other mining companies working deposits around Peru.

Placer mining was started by the Incas or other tribes long before the coming of the Spaniards, and continues until today.  The gold is found in virtually all the rivers flowing east or west of the Andes Mountains, but most of the operations are artisanal with a lot of small operators.  There is some illegal mining operations with an occasional town springing up in the middle of nowhere if there are especially rich diggings.

The mineralized area in Peru is limited to the Andes Mountains a narrow strip of land along the Pacific Coast a little over 100 km wide. It is within this area that is an active convergent margin hosting a diverse number of some of the world's richest gold, copper, zinc, lead and silver deposits. Many of these are world-class deposits that are currently being exploited. Much of this mineral wealth as a result of my impulses during key times within the past 70 million years with the geological setting a major deposit being related to structures that have been active since the early Paleozoic.

This narrow belt along the coast of South America is a good example of a metallogenic province that mainly is the result of a 240 million year old history of subduction related tectonics along the western margin of the Brazilian Shield that began in the early Triassic and continues to this day. This is than a continuous cycle of east directed subduction beneath the South American plate called the Andean cycle that is formed a linear volcanic and plutonic arc that has a landward back arc basin in eastern side of Peru.
During this period of 240 million years magmatism in the area was episodic that was regularly disrupted by shortening events causing the inversion of the back arc volcano sedimentary sequences along with the migration of the center of volcanism and intrusions.

The major ore systems in Peru are associated with arc-related igneous and volcanic rocks. It was this activity along the continental margin where the early episodes are dominated by copper -- gold minerals that are close to the subduction trench. The sequence of minerals progressed eastward to zinc -- lead then further eastward into tin -- tungsten. There is a regular sequence of mineralization as you get further way from the edge of the continent.

Tuesday, March 20, 2012

Gold Occurrences in Ecuador

Coat of Arms of Wcuador

Ecuador is nestled between Colombia and Peru, but has seen nowhere the amount of exploration the other two countries have, a statement that is especially true of Peru.  According to some of the giants of the gold mining industry like Barrick and Newmont Ecuador is the prime place for exploration.  This is where the gold discoveries are going to be made, not in Peru where they are already mining gold.  Even though Colombia and Peru contain some really big deposits of gold Ecuador just hasn’t seen the level of exploration that has gone on in these other countries.

A great deal of gold has been found over the ages in south-eastern Ecuador including the gold used by the Incas from Pizzaro in the early 1500s.  This was enough gold to fill a room, but the Spaniards still executed the last of the Inca emperors.  The gold found here is epithermal in nature with drilling results by Aurelian Resources indicating a multi-million ounce deposit at their Fruta Del Norte project.

Today there are several exploration companies that are uncovering the enormous potential of this little explored region of South America.  Many of these exploration companies are working within a few kilometers from where Aurelian has its Fruta Del Norte property.  Many of these companies are exploring deposits that could potentially yield many ounces of gold.

Chimborazo one of the many volcanoes found in Ecuador that have epithermal gold deposits associated with them.
Photo by David Torres Costales

The majority of these companies are from Canada that are talking among themselves about arranging joint ventures.  The country of Ecuador is clearly open for business with all indications they have a government that is open for business and are prepared to act in a responsible manner.

Most of the Canadian and other companies are concentrating on the potential of developing lode gold deposits although there is plenty of room for placer deposits along the rivers and streams of Ecuador.  A great many of the deposits in this district are along tributaries of the Amazon River.

The potential for finding gemstones in this part of the world is also high it is just across the border in Colombia where some of the largest emerald mines in the world are located.  Years ago your author while exploring another of the tributaries of the Amazon discovered several sandbars that were littered with gem grade topaz that also contained placer gold.

Thursday, March 15, 2012

Worldwide Gold Deposit Maps

Gold Deposits found in Mesozoic Terrane
Gold deposits found in Cenozoic Terrane
Alluvial gold deposits

This collection of maps is pretty much self explanatory and they do depict where gold can be found throughout the world.  The maps themselves are in Public Domain.
This depicts the gold deposits that are found in Precambrian Terrane

This depicts gold deposits found in Paleozoic Terrane

Gold Occurrences in Venezuela

Coat of Arms of Venezuela
By Sigge Kotliar

President Hugo Chavez has nationalized the gold mining industry in Venezuela as of August 23, 2011 after he has signed a decree.  In the terms of the decree all mining companies will have to sell the gold they extract from Venezuelan soil to the government.  This decree insures that the government boosts the government control of all gold mining operations.  Under the terms of the decree private mining companies will be able to participate in mining operations in Venezuela only as minor partners of the government.  This law took effect with its publication in the Official Gazette that says all gold mined in Venezuela will be sold or turned over to the government.

It was revealed that over 40,000 hectares of land and over 15,000 people were freed from conditions of slavery as part of Plan Caura as part of the Venezuelan plan to curb illegal mining.  The chief of Venezuela’s Operational Strategic Command that was formed in 2010 when the Bolivarian Armed Forces were given the task of stopping illegal mining in the southeastern part of Bolivar state.

A great deal of the gold found in Venezuela is associated with the Guyana Shield that is a Precambrian Shield that extends into Brazil, Guyana, Surinam and French Guiana.  The shield itself consists of several distinct geological parts that can be correlated to tectonic events that occurred in West Africa.  This consists of several rock types with gneiss, amphibolite, itabirites along with intrusive granites that are all found in the Imataca Complex of Venezuela. Collectively the whole complex is called the Amazonian Shield that is between 3.6 and 2.7 billion years old.  It is in this complex of rocks where gold is found in Venezuela and surrounding areas.

In the 1950s Venezuela had a large gold rush that was due mostly to the placer deposits found along the Caroni and Paragi rivers and in the area close to its border with Brazil.  Briefly the output of gold rose as high as 20 tonnes per year with most of the gold going to the Banco Central de Venezuela who in turn sold the gold abroad.  After these deposits were worked out several foreign mining companies attempted to work other gold deposits in Venezuela but were prevented from doing so by restrictive mining laws, bureaucracy and law suits brought against them. 

The best of these projects was located at Las Cristinas in south-eastern Venezuela where the Canadian Mining Company, Placer Dome.  They partnered with Corporacion Venezolana de Guyana (CVG) the Venezuelan industrial and mining company.  The partnership was plagued with constant delays and at the time low gold process until in 1999 Placer Dome threw up its hands and closed the mine even though it had the potential of producing at least 16 tonnes of gold.  In the end the government revoked the license to proceed at Las Cristinas.  

Monday, March 12, 2012

Gold Occurrences in Puerto Rico

Coat of Arms of Puerto Rico

Its very name in English means Rich Port and yes there is gold in Puerto Rico.  Over seventy years before Puerto Rico became an American Possession the Spaniards established a mine on the Mami River that the first Americans found as ruins in 1898.  This old mine was discovered by W.A. Shoemaker who was traveling all over the island in behalf of the American Association of Manufacturers and the Philadelphia Commercial Museums on a commercial investigation of the island and its resources while on the outlook for possible commercial ventures.  The old goldmine on the Mami River was one of his discoveries.

Gold was discovered in the Central Highlands of Puerto Rico in the early 16th century and there were several gold mines operating until the end of the 16th century.  For many centuries gold mining was missing from the Island and wasn’t revived until 1828 when a mine was established once again in the Central Highlands.  

Gold was the first economy established on the island that was shipped to Spain when it was mined.  These mining ventures were built on the backs of the Taino Indians who several times revolted against their Spanish conquerors until their survivors were driven to the interior of the island where many of their women were taken as wives by the Spanish sailors finally creating the present day Puerto Ricans. 

Gold is found in five different types of deposits on the island of Puerto Rico as placer deposits, copper skarns, porphyry copper-gold deposits and acid-sulfate precious metal deposits.  It is thought by the USGS that there is plenty of opportunity to find additional deposits of gold on the island as well as in the surrounding continental shelves.  While there is no real evidence of these deposits it is possible that there are large bulk concentrations of gold in the intensively acid sulfate altered areas.  Many of the skarns are accompanying tertiery intrusives and in many of the polymetallic veins found in Puerto Rico and its offshore areas.

The first gold deposits worked by the Spaniards were probably placer gold.  These deposits can be found associated with all the major rivers on the island that drain north from the Central Highlands.  Although these deposits are mostly small it has been estimated that they may aggregate as high as 1 million ounces of gold.  There are also placer gold associated porphyry copper-gold deposits of the Utuado District where it is found in the small drainage basins of the surrounding area.

It is also thought that several underground placer deposits could be hosted in the many caves in the karst topography found on the north side of island.  Although these deposits are probably small they could also be extensive and for the most part are little explored unlike the surface rivers where there was extensive exploration under the Spaniards during the 1500s.

Sunday, March 11, 2012

Gold Occurrences in Cuba

Coat of Arms of Cuba

Although Cuba has been off limits for Americans since shortly after Fidel Castro took power in 1959 an active mining industry has sprung up with gold being one of the products being mined.  Other mineral products include copper and zinc in deposits found the central province of Villa Clara under the framework of the Bolivarian Alternative for the Americas (ALBA) according to reports seen in the weekly newspaper Trabajadores of Nov. 11, 2008.

Cuba according to Armando Garcia the chief of operations for the view of the Geominera Del Centro Company said the gold mine will be located in the municipality of Placetas copper and zinc mine being located in Manicaraqua.  He went on to say Cuba is developing several economic and social programs under the ALBA initiative that will promote regional integration as an alternative to the made in the US free trade agreement. Other projects that are being promoted under the spell ALBA include the fuel refinery and derivative processing facilities at Cienfuegos.

Cuba has a history of mining that extends back over 300 years, and the period from 1900 to the present time mining is a permanent activity. During World War II the mining of manganese, some copper and nickel was the most important meeting that occurred in Cuba. Cuba is also capable of producing nickel and cobalt ranks it sixth in the production of medical and produces about 8% of the world's supply of cobalt. The production and minerals is mainly state-controlled, although recently the government has tried to amend the mineral laws that will hopefully change the way mining is conducted in Cuba. Geominera in 1993 utilizing state funds was formed as a private company for the purpose of gold and base metals exploration.

The greatest amount of gold production in Cuba was in 1998 when the country produced 1000 kg of gold. This number has fallen back to around 500 kg according to the last reported figures.  The Delita concession on the Isla de la Juventud contains an estimated 1.5 million ounces of gold with the government planning for a possible open pit mine.

Cuba also has some placer gold mainly found as decomposed stringers of quartz in laterite.  The placer gold in Cuba is extremely fine and difficult to mine hence there is little or no placer mining on the island.

Wednesday, March 7, 2012

Gold Occurrences in Haiti

Coat of Arms of Haiti

When he was asked to describe what kind of land was to be found in Haiti Christopher Columbus picked up a piece of paper crumpled it and dropped it on the table. This was the kind of land they had in Haiti he told them it is extremely mountainous as well as the land in the Dominican Republic where just over the border from Haiti they actually have mountain peaks that are more than 10,000 feet high. The Gold occurrences in Haiti have been mainly discovered in the northern mountains of not only Haiti but the entire island of Hispaniola that also includes the Dominican Republic.

The rocks and the entire island of Hispaniola are no older than the Cretaceous Period although on and off laying island from the main island there are some rocks that are arguably from the Paleozoic era.  First gold mines on the island were established by the Spaniards in 1520. It was these gold mines that led to the extinction of the Arawak Indians on the island because the Spaniards used them as slaves to work the mines. The very name Haiti is one of the few words that have survived the Arawak Indians, it means mountainous place.

Once the Spaniards discovered the tremendous amounts of gold to be had in Mexico Gold mining operations in Haiti came to an ending and for centuries Gold Mining almost ceased on the island. Gold was recently rediscovered in Haiti along with other base metals in booting copper and zinc. These deposits are now being explored by many prospectors and mining companies from the US and Canada.

Since the gold mining industry has reestablished itself in Haiti there has been a growth of artisanal mining throughout the country. And there are gold buyers that make you regular circuit of the country buying gold from the miners in what has been described as a circus atmosphere somewhat reminiscent of a flea market. There are many places where gold has been found in hard rock deposits, but there are many places where it can also be found as placer gold.

One of these deposits located at Grand Bois is estimated to contain over 4,000,000 tonnes of ore that averages 1.9 g per tonne. The gold is found in the oxidized zone near the surface of the earth making it extremely amenable to open pit mining. There are other deposits of gold found throughout the northern part of the island, but Grand Bois is the largest. Most of the gold of his been discovered is in the vicinity of where two fault lines intersect. Copper is another metal that his been found on the island in considerable amount that may prove to be more monetarily rewarding then the gold deposits.