Creighton Mine

Discovery and development The deposits at Creighton mine were the first mineralized deposits discovered in the Sudbury Igneous Complex (SIC) mining camp. They were discovered by Albert Salter in 1856 due to deflections in his compass readings. Production at Creighton Mine began in 1901 under the Canadian Copper Company, and later the International Nickel Company (INCO). The mine was an open-pit mine from 1901 to 1908, and was transitioned to an underground mine in 1906. In 1969, the 7138-foot No. 9 shaft was completed, making it the deepest continuous mine shaft in the Western Hemisphere. due to the expense of maintaining the settlement to modern standards. The community of Creighton was closed on June 30, 1988. == Geology ==

The Creighton Mine lies within the Sudbury Igneous Complex. The bolide impact created a crater 200 to 250 km across and melted the pre-existing rock, which partially filled in the crater. Copper, nickel, and PGE rich sulfides settled to the base of the molten Sudbury Breccia, and formed veins and stockworks of mineralization in the footwall (the non-igneous rocks underlying the SIC). Sulfide-rich base metal intrusions also contribute to the mine's mineralization. Sulfide mineralization on the property occurs as massive to disseminated sulfides, occurring as massive sulfides near the footwall and grading towards disseminated sulfides towards the hanging wall. Less common and non-ore minerals which occur at the mine include altaite, argentopentlandite, arsenopyrite, biotite, bornite, cassiterite, cobaltite, epidote, froodite, gersdorffite, gold, heazlewoodite, hessite, hollingworthite, insizwaite, irarsite, kotulskite, marcasite, maslovite, melonite, merenskyite, michenerite, millerite, moncheite, muscovite, nickeline, parkerite, quartz, rutile, silver, sperrylite, sphalerite, stützite, tin, and tsumoite. ==Production==

Creighton Mine is primarily a nickel, copper, and PGE mine, but also produces gold, silver, cobalt, selenium, and tellurium. which produced 793,000 tonnes of ore with grades of 1.62% copper and 2.8% nickel.. 2018 saw production rate reach 608,000 tones of ore with grades of 2.77% copper and 2.5% nickel. While 2019, saw 6,130,000 tonnes of ore produced, with copper grades of 2.67% and nickel grades of 2.68%. Ore is processed off site at Vale's Clarabelle Mill for nickel and copper, and the platinum group element (PGE) intermediates are sent to Vale's processing facility in Port Colborne, Ontario. == Seismic events ==

Creighton mine contains four families and twelve total of shear zones. This re-mobilization has resulted in several earthquakes and rock burst events felt in nearby Sudbury and the surrounding areas, with a total of 123 felt and unfelt seismic events between January 2000 and September 2013. ==SNOLAB==

Creighton Mine's level is home to the world's deepest cleanest underground physics laboratory. Originally excavated for the Sudbury Neutrino Observatory (SNO), it has been expanded into a general-purpose facility called SNOLAB. The original laboratory, the SNO, was a heavy-water neutrino "Cherenkov detector". In 2004, a $7.5 million 3-story lab was constructed for the SNO on the grounds of the Creighton Mine, creating the foundation for the laboratories known today as SNOLAB. ==Creighton deepening project==

In 2005, two projects were underway to allow deeper mining at Creighton Mine. The first was an $8-million, four-year diamond drill exploration program that will allow for ore tonnage to be defined down to the level. The second was a $48-million expansion project that established production ore at the level and was estimated to bring 1.8 million tons of high-grade ore into production from 2006 to 2011. This expansion was carried out by SCR Mining and Tunneling. In 2007, Vale announced the exploration drilling increased the proven and probable reserves at the Creighton mine to 32 million tons of 2.2% nickel and 2 to 2.3% copper grading, up from the previously defined 17 million tons of 3.2% nickel and 2.5% copper grading. This exploration also led to the discovery of high grade PGE ore at the 2150 and 3200 meter mine levels. In 2013, Phase 3 of the Creighton Mine Deep project was underway. This expansion project will cost $247 million, will increase the mine's depth to 8020 feet (2444 meters), and is estimated to increase the mine's lifespan to at least 2027. == Environmental projects and concerns ==

Diesel to electric In 2018, Vale announced they are transitioning their deep zone fleet of vehicles from diesel to electric. This is an ongoing project, as old equipment is replaced with electric equipment once it has reached the end of its life. This move towards electric vehicles not only reduces the environmental impact of the mine, but also allows for a reduction in heat generation and diesel contamination by these vehicles at depth. Groundwater treatment Groundwater naturally flows through the tailings area of the Creighton mine, posing an environmental contamination risk. To protect against contamination, groundwater from the tailings area is pumped to and treated at water treatment plants. Once treated, the water is discharged into the local watershed. Underground greenhouse The 4800 foot level of Creighton Mine is a fully automated greenhouse. This greenhouse grows approximately 100 000 jack and red pine trees, which will be used in regreening and remediation of the Sudbury basin. ==See also==