Kerr Sulphurets Mitchell
Encyclopedia
Kerr-Sulphurets-Mitchell (KSM) is an active mine exploration
Mine exploration
Mine exploration is a hobby in which people visit abandoned mines, quarries, and sometimes operational mines. Enthusiasts usually engage in such activities for the purpose of exploration and documentation, sometimes through the use of surveying and photography. In this respect, mine exploration...

 project 65 km northwest of Stewart, British Columbia
Stewart, British Columbia
Stewart is a small town, incorporated as a district municipality at the head of the Portland Canal in northwestern British Columbia, Canada. In 2006, its population was about 496.-History:...

 (1,545 km northwest of Vancouver, British Columbia). The property is 100% owned by Toronto-based Seabridge Gold
Seabridge Gold
Seabridge Gold is a Toronto-based North American resource exploration company. It owns Kerr-Sulphurates-Mitchell, a copper-gold-silver-molybdenum porphyry project in northern British Columbia. The deposit's proven-probable reserves includes 38.5 million ounces of gold, 214 million ounces of...

. Denver-based royalty company Royal Gold
Royal Gold
Royal Gold is a precious metals company with royalty claims on gold, silver, copper, lead and zinc at mines in over 20 countries...

 owns a 2% net smelter return
Net smelter return
Net Smelter Return is the gross revenue that the owner of a mining property receives from the sale of the mine's metal/non metal products less transportation and refining costs. As a royalty it refers to the fraction of net smelter return that a mine operator is obligated to pay the owner of the...

 royalty on the mine. Since May 2011 the project has also been called Kerr-Sulphurets-Mitchell-Iron Cap due to the addition of significant reserves from the Iron Cap region.

When operational it will feature four open pit mines, a processing plant and a tailings
Tailings
Tailings, also called mine dumps, slimes, tails, leach residue, or slickens, are the materials left over after the process of separating the valuable fraction from the uneconomic fraction of an ore...

 facility. It is the largest undeveloped gold deposit in Canada and one of the world's biggest copper-gold porphyry
Porphyritic
Porphyritic is an adjective used in geology, specifically for igneous rocks, for a rock that has a distinct difference in the size of the crystals, with at least one group of crystals obviously larger than another group...

 deposits.
Though 2P reserves are significant (39 million ounces of gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, 214 million ounces of silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

, 9.9 billion pounds of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 and 257 million pounds of molybdenum
Molybdenum
Molybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...

) they only represent about 65% of the mine's total resource of each metal. The mines have a 52 year mine life (up from the 37 year estimate in 2009) and in the first seven years gold production costs are estimated to be $105/oz. Environmental/geological assessment was done by Rescan and Wardrop (other Rescan projects include Pueblo Viego and Ekati). All of the proven reserves and 75% of the proven + probable reserves are in the Mitchell Valley. Although the area's pyritic gossans have been clearly visible for a while, mining has never been attempted before.

It neighbors Pretium Resource's Snowfield project (previously owned by Silver Standard Resources
Silver Standard Resources
Silver Standard Resources is a Vancouver based silver, zinc and tin producer that owns the largest silver mine in Argentina. In addition it engages in exploration activity throughout the America's and Australia...

). Snowfield has reserves of 25.9 million ounces for gold, 3 billion pounds for copper, 75.8 million ounces for silver and 258.3 million pounds for molybdenum. Barrick Gold
Barrick Gold
Barrick Gold Corporation is the largest pure gold mining company in the world, with its headquarters in Toronto, Ontario, Canada; and four regional business units located in Australia, Africa, North America and South America...

's Eskay Creek
Eskay Creek
This is a rich gold mining area in the Unuk and Iskut River region on north coastal mountains of British Columbia. Remote and rugged, the area hasa service road from the Stewart-Cassiar Highway at Bell 2 Services....

 Mine is 20 km northwest of KSM.

Image description: The map to the right shows the boundary between the KSM property and Pretium Resource's Snowfield-Bruceback project and the road connecting them to Barrick Gold's Eskay Creek mine]. The large land impressions that can be seen running through the Kerr and Sulphurets properties are glaciers (Sulphurets Glacier, Mitchell Glacier), icefields and lakes (Bruceback Lake is to the right just outside the area shown). More detailed representation here http://wikimapia.org/p/00/01/76/48/91_big.jpg.

History and background

The property was purchased by Seabridge Gold in 2000 from Placer Dome
Placer Dome
Placer Dome Inc. was a large mining company specializing in gold and other precious metals, with corporate headquarters in Vancouver, British Columbia, Canada....

 (currently Barrick Gold) and exploratory activity began in 2006. Since then exploration by Seabridge has added about 20 million ounces of gold resource.

A preliminary feasibility study released in May 2010 increased reserves by 61% for silver (133 million ounces), 42% for copper (7 billion pounds), 27% for gold (8.5 million ounces) and 22% for molybdenum; Most of the new reserves came from the Iron Cap portion of the property which wasn't part of previous development plans.

Exploration spending in British Columbia was $521 million in 2008 and 2009 combined with spending in 2009 being the "6th highest total in the last 20 years". Besides KSM there were 87 other significant exploration projects in BC that year (60% of the companies involved were based in BC).

In 2010 a comprehensive environmental assessment of the area was completed by Canada's ministry of environment. While the study was being done the Canadian Environmental Assessment Agency
Canadian Environmental Assessment Act
The Canadian Environmental Assessment Act, S.C. 1992, c. 37 is an Act of Parliament that was passed by the Government of Canada in 1992...

 (CEAA) was undergoing a review of its own by the Supreme Court of Canada.

KSM is located near the headwaters of a tributary of the Unuk River, which flows into Behm Canal near Ketchikan. Seabridge unveiled its development plan during a public meeting in Ketchikan in October 2011 before a crowd of skeptical residents.

Geology

The sulphurets zone has the lowest elevations while the highest elevations of the entire valley region are covered by glaciers. The main sulphides are pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...

 and chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...

 and all mineralization came from processes occurring deep below the earth (hypogene). Quartz stockwork is the main mineral type.

Kerr - Recognized as a porphyry deposit since 1987 (specifically a modified porphyry deposit with unique characteristics). A hydrothermal system generated by intrusion of monzonite
Monzonite
Monzonite is an intermediate igneous intrusive rock composed of approximately equal amounts of sodic to intermediate plagioclase and orthoclase feldspars with minor amounts of hornblende, biotite and other minerals...

 naturally upgraded mineral grades (caused by one of the many deformations occurring in its geological history). That deformation introduced new veins consisting of a combination of sulphides like carbonate with minor chalcopyrite, bornite
Bornite
Bornite is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system .-Appearance:Bornite has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places...

 and quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

 with carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

, chlorite
Chlorite
The chlorite ion is ClO2−. A chlorite is a compound that contains this group,with chlorine in oxidation state +3. Chlorites are also known as salts of chlorous acid.-Oxidation states:...

, chalcopyrite.

Sulphurets - This deposit is centered on the Sulphurets Thrust Fault where volcanic activity helped to form it (portions previously exposed to fracturing form the site's gold zone). Copper is located within the Main Copper Zone and the Raewyn Copper-Gold Zone. Gold is found in its highest concentrations at the The Breccia Gold Zone (up to 5.6 g/t in the K-feldspar hydrothermal breccias and up to 21.2 g/t in the siliceous breccias).

Currently (July 2011) has 3 million ounces of inferred gold resource that Seabridge has an agenda to upgrade by 2012. At a depth between 42.9m and 65.9m Sulphurets has a gold grade of 1.26 g/t (1.12 g/t beyond 79m).

Mitchell - The deposit has been exposed through erosion of the Mitchell Thrust Fault. Copper-gold mineralization occurs mostly in a zone 300 to 600 meters thick. Glacial melting increased exposure of the deposit.
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