Marudi is iron-formation-hosted gold (“IFG”) deposits Gold mineralization at the Marudi Property is regarded as being related to iron-formation-hosted gold (“IFG”) deposits that occur in other cratonic greenstone belts (e.g. Lupin, Musselwhite, in Canada, and Homestake in the western U.S.)
These deposits can be remarkably long- lived with sizeable gold production (e.g. +/- 115 years, 65 M ozs Au).
They have a strong association between gold and iron sulfide minerals, the presence of gold bearing quartz veins and structures, the occurrence of deposits in structurally complex terranes, and the lack of lead and zinc enrichment.
In stratiform IFG deposits much of the gold is uniformly disseminated in stratigraphically continuous horizons in well-laminated units of cherty, sulfide-rich BIF that are conformably interlayered with gold and sulfide poor BIF and clastic sedimentary rocks. Iron sulfide minerals are deformed and metamorphosed but oxide BIF is lacking. Late quartz veins or shear zones are volumetrically significant but their control on gold and iron-sulfide is unclear. Arsenic bearing minerals, if present are generally restricted to alteration zones immediately proximal to late quartz veins.
World examples include Lupin, in Canada, Homestake in North Dakota (US), and Morro Vehho and Cuiaba in Brazil.
The strataform gold horizons at Marudi are genetically different from gold deposits and occurrences within the Guiana Shield in northern Guyana that have formed in structural (orogenic) belts in successive back-arc closure and extensional oceanic arc systems caused by migrating spreading ridges.
These deposits form along convergent margins during terrane accretion, translation, or collision, related to plate subduction and/or lithospheric delamination. Brittle faults define conjugate patterns that are either trending north-northwest–south-southeast or north-northeast–south-southwest. Paleo-reconstructions indicate a similar pattern in West Africa.
In West Africa the controlling structural trend is northeast-southwest. When compared at a regional scale, shear patterns of West Africa and those of the Guiana Shield appear to define a nearly conjugate pattern.
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The Homestake Mine was a deep underground gold mine located in, South Dakota.
Until it closed in 2002 it was the largest and deepest gold mine in North America.
The mine produced more than forty million troy ounces (43,900,000 oz; 1,240,000 kg) of gold during its lifetime.
The gold ore mined at Homestake was considered low grade (less than one ounce per ton), but the body of ore was very large. Through 2001, the mine produced 39,800,000 troy ounces (43,700,000 oz; 1,240,000 kg) of gold and 9,000,000 troy ounces (9,870,000 oz; 280,000 kg) of silver.[citation needed] In terms of total production, the Lead mining district, of which the Homestake mine is the only producer, was the second-largest gold producer in the United States, after the Carlin district in Nevada.
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GoldCorp's Musselwhite
The mine has estimated reserves of 2.29 million ounces.
Location Opapamiskan Lake, Ontario
Ownership 100%
Type of Mine Underground
Processing Method Carbon in pulp recovery, cyanide certified
Milling/Processing Capacity 4,500 tonnes per day
Power Demand 25 megawatts
Number of Employees & Contractors 749
Gold Production (guidance for 2018)
265,000 ounces
AISC (guidance for 2018)
$775 per ounce
Gold Reserves (proven and probable) 1.85 million ounces
Gold Resources (measured and indicated) 310,000 ounces
Gold Resources (inferred) 1.17 million ounces
A fly-in, fly-out operation located approximately 500 kilometres north of Thunder Bay, Canada, Musselwhite has produced over 4 million ounces of gold since achieving commercial production in April 1997.
Musselwhite’s ore is mined from two main zones below Lake Opapimiskan. Ore is processed onsite using a circuit that includes crushing, grinding, leaching by cyanidation, carbon in pulp recovery and electrowinning. Gold recoveries are 96%.
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Lupin Mine was a gold mine in Nunavut Territory, Canada.
It opened in 1982 and was originally owned and operated by Echo Bay Mines Limited, who in 2003 became a fully owned subsidiary of Kinross Gold Corporation.
Echo Bay Mines Ltd. brought the mine into commercial production in 1982
Lupin Gold Mine produced approximately 3 million ounces of gold.