Sulphide mineralization within the sub-layer consists of disseminated to massive sulphide generally zoned from massive sulphide at the footwall to disseminated sulphide ore towards the hangingwall. The PGE-Au content of the contact deposits is variable but low. The bulk of the economic North Range Ni-Cu occurs within the granite breccia. This footwall breccia consists of fragments of country rock, exotic ultramafic inclusions and rare sub-layer and mafic norite xenoliths in a metamorphic-textured quartzo-feldspathic matrix.
Mineralization occurs as blebby disseminations and fragments of sulphide, veins and stringers, and as accumulations of massive sulphide within bodies of footwall breccia. A transition zone exists between the footwall breccia and non-brecciated footwall rock with the greatest amount of sulphide found at the base of the footwall breccia. Two types of footwall deposits have been defined in the North Range. Footwall mineralization is highly fractionated compared to the contact mineralization and is emplaced within or near thermally metamorphosed Sudbury Breccia into dilatant fractures.
A physical connection between the contact sulphide and footwall sulphide is not always preserved or recognized, the exceptions being at the Quadra FNX Mining Ltd. The South Range Footwall Breccia underlies the sub-layer and is derived from melanocratic metasedimentary rocks and metavolcanic rocks. Ni-Cu mineralization occurs as disseminated to massive sulphide within the sub-layer.
These deposits are generally zoned from massive ore at the footwall to disseminated sulphide ore toward the hangingwall. The PGE-Au content of the contact deposits is generally low. Similar to North Range contact deposits, Ni-Cu mineralization occurs within bodies of footwall breccia with minor amounts of quartz diorite. They can extend for many kilometres into the Sudbury Structure wall rock, and may be radial or concentric to the contact of the SIC with distinct, sharp contacts.
Footwall breccia also occurs here as sheets and discontinuous lenses concentrated along the lower contact of the SIC, and as a major component of some of the offset dykes. Mineralization consists of zones of disseminated blebby and massive Ni-Cu-PGE-Au sulphide that is spatially associated with inclusion-rich phases of quartz diorite, as well as with local structural complexities of the dykes.
Areas between orebodies consist of barren quartz diorite or weakly mineralized inclusion-rich quartz diorite. Underground mining is composed of both remnant pillar extraction in older mining blocks and new mining zones. The underground mining method selection is based primarily on deposit geometry but also on a number of other factors including available infrastructure, geotechnical constraints and experience at the mine. Sill pillars are recovered using URM. Garson Mine uses slot-slash variation and URM mining methods.
The first mining activity on the assets currently owned by KGHM in Sudbury began in the first half of the 19th century — mainly nickel ore mining. At McCreedy West, exploration resulted in the discovery of a contact nickel deposit, the mining of which began in In the years mining was conducted on the copper footwall deposit.
Since , the mine has been mining with some interruptions copper and precious metals deposit.. It is difficult to see any minerals unless you get a chance to wash down the faces or the muck in the drawpoints. Common in the lower Onwatin member of the S. Also found in the Vermilion and Errington Mines associated with the sulphides in calcite. Aragonite occurs in limited occurrences in the Sudbury Structure. Some very long crystals, associated with pyrrhotite and cubanite were collected at the Strathcona Mine.
The Vermilion Mine, in the south-west of the Sudbury Basin, is the type locality for this rare mineral. Excellent crystals have been recovered, in the past but the location has now been largely rehabilitated and it is difficult to recover any interesting mineral specimens. Arsenohauchecornite crystals up to 11mm have been recovered in the past.
Usually, they are embedded in pyrrhotite and chalcopyrite, at the Vermillion Mine. Bornite is relatively uncommon in the large massive sulphide deposits and disseminated sulphide deposits that have been the source of most of the metals in the Sudbury Basin.
It has been found more commonly in the smaller, high-Cu-Ni-pgm footwall deposits, particularly in the northwest rim of the Sudbury Basin. On occasion, very good crystals have been recovered to Chalcopyrite rarely occurs in significant crystals in the Sudbury ores. It is the major source of copper in all types of ores and many, many millions of tonnes of chalcopyrite have been mined in the Sudbury Basin over the past years.
The Sudbury Basin ores are a significant source of cobalt metal that is recovered as a by-product of nickel smelting and refining.
Although the bulk of cobalt content of the Sudbury ores is derived from cobalt in solid solution with nickel in pentlandite, some of the cobalt content of Sudbury ores is derived from cobaltite gersdorffite and other cobalt minerals in the ores. Sharp cobaltite crystals up to 13mm in size have been recovered from the Sudbury Basin, usually embedded in massive sulphides such as chalcopyrite and pyrrhotite. Native copper occurred only at the Vermillion Mine in Denison Township, in flat, dendritic crystal groups to 5mm in rock fractures.
Cubanite is thought to be a significant portion of the make-up of the Sudbury Basin ores although it is difficult to quantify. Polished sections of copper ores often show lamellae of cubanite in chalcopyrite in the high Cu-Ni-PGM and massive sulphide deposits. Since it is difficult to visually distinguish cubanite from chalcopyrite in rough ores, the cubanite is often un-noticed.
Excellent crystals of cubanite have been found at the Strathcona Mine, in the s by Mr. Ron Lee, including some very large ones, up to 45mm in length. The cubanite crystals at Strathcona Mine were in cavities on the levels associated with calcite and pyrrhotite crystals in a large horizontal fracture, near an olivine-diabase dyke.
Galena occurs in late north-south striking tension veins that cut through the SIC. The veins are 1 to 10cm thick and sometime contain calcite, marcasite, sphalerite and galena crystals. These are more common in the South Range mines. Gersdorffite as octahedral crystals and massive mineralization have been noted in the arsenic-rich zones of SIC orebodies, particularly at Garson, Falconbridge and Frood mines.
Crystals of gersdorffite have usually been up to few mm. Considerable gold has been recovered from the Sudbury ores, over the years, primarily as a by-product of copper recovery and refining. This is largely due to the presence of fine particles of electrum, a natural alloy of silver and gold. Native gold is rarely seen in the Sudbury basin with one exception, at the Vermilion Mine. This mine was precious metals rich and was operated as, largely, a precious metals metals mine.
Significant native gold occurred in the Vermilion Mine surface gossan, primarily as sheets and masses in sulphide and carbonate fractures in the host rock. Magnetite is ubiquitous in the Sudbury ores. It can often be seen disseminated in massive ores as individual, rounded crystals. Really well crystallized specimens have not been recovered. Marcasite occurs in late north-south striking tension veins that cut through the SIC.
This mineral is usually found as acicular crystals in most world occurrences. Acicular crystals have been recovered in the Sudbury deposits, as well, particularly at the McLennan Mine, associated with siderite. Of particular interest, though are the large cleavable masses of millerite that occur in some orebodies, particularly the footwall orebodies such as at Levack, McCreedy and Strathcona mines.
Cleavage planes up to Such cleavages are usually embedded in massive chalcopyrite. Nickeline is usually only present as massive mineralization in arsenic-rich zones of Sudbury deposits, particularly at deposits in the south S. No crystals of significance have been found to-date.
Considering the vast tonnages of pentlandite that have been mined in all ore types and processed into nickel metal, at Sudbury, there are no well-formed crystals and anything resembling a crystal rare. It is easy to see small crystals eyes of pentlandite embedded in pyrrhotite in higher-grade, massive ores because of the relatively good parting or cleavage that reflects light well.
Pyrite is common in the Sudbury District ores but, again, rarely in good crystals. Occasionally, interesting, groups of curved crystals are found in open areas in fault mineralization. Most of the time, the crystals are octahedra up to 30mm, embedded in pyrrhotite and or chalcopyrite.
The bulk of the pyrite occurs as grains and thin coatings around pyrrhotite. Pyrrhotite is ubiquitous in the ores of the Sudbury district and is the major sulphide composing the massive and disseminated ores in the main deposits. Pyrrhotite is rarely recovered in good crystals. It is usually found as massive and disseminated mineralization associated with chalcopyrite, pentlandite, magnetite and gangue mineralization.
One massive orebody at Strathcona Mine contained and area with large, enmeshed hexagonal crystals to 20cm. Quartz is a common vein filling in the Sudbury ores but does not often occur in specimen quality crystals. Quartz mostly occurs only as crystals mm in size. Silver occurs in quantity in solid solution, particularly with copper minerals.
The copper refineries in the Sudbury District have produced hundreds of millions of troy ounces of silver as a by-product of electrolytic copper refining over the decades.
Specimens of native silver or silver minerals are relatively rare, however. Sphalerite occurs in late north-south striking tension veins that cut through the SIC. Sphalerite is also found as fine-grained mineralization, associated with fine-grained galena and gold at the Vermillion and Errington Mines in the Onwating formation. Sperrylite Crystals have been found at a number of Sudbury Mines in some quantity but the best specimens have been recovered from the Vermilion, Frood and Broken Hammer Mines.
The Vermillion Mine is the type locality for Sperrylite. A Sudbury chemist, Francis L. Sperry, identified the new compound and in the mineral Sperrylite was published as a new species. Many, many specimens of sperrylite crystals, mostly embedded n chalcopyrite, have been recovered by geologists and mineral collectors over the years from old mine dumps on the property.
These dumps have been re-worked for the precious metals content and the original site of the mine has now been largely rehabilitated with very little to be found now. The Frood Mine was a huge, operating, underground mine for the past century and access to the mine workings and dumps has not been possible. Regardless, some sperrylite crystal specimens have been recovered and preserved by geologists in precious metals-rich areas of the mine, at various times over the years.
The Broken Hammer Mine was a relatively new and small addition to the past producing mines of the Sudbury District. In its short lifetime, the Broken Hammer Mine produced some excellent sperrylite crystals, first from a bulk test-mining of ore and then from a 1.
Interestingly, sperrylite crystals from this operation occurred differently from those at other Sudbury District mines.
Metallic Te, BI, As Sb: Altaite, Argentopentlandite, Breithauptite, dyscrasite, empressite, galenobismuthite, hessite, mackinawite, maucherite, parkerite tl , schapbachite, skutterudite, tetradymite, tellurobismuthite, tellurohauchecornite. Platinum Group: froodite tl , insizwaite, kotulskite, merenskeyite, mertierite, michnerite tl , moncheite, niggliite, palladian melonite, stanopalladinite, sudburyite tl. The majority of the rare minerals listed above were identified from samples collected in the copper rich portions of the various orebodies around the SIC.
Copper-nickel massive liquid sulphides can be mobile at temperatures as low as C. For this reason a variety of elements such as Au, Ag, Pt, Pd and others were able to differentiate from the contact orebodies and be deposited in favorable structures below the contacts of the SIC and into most of the quartz diorite offset dykes.
We appreciate being able to use the great photographs of Broken Hammer Mine sperrylite photographs by Michael Bainbridge. Thanks to Dr.
Pye, A. Naldrett, and P. Smith, P. I feel honoured to be associated with and very familiar with Sudbury after many years of working on various project and commercial endeavours. I learned a lot! As well, we surveyed in the lines to direct miners on direction and limits of the various blasted excavations. It was a great job! I lived in a bunkhouse on Copper Rd. There were a couple of my classmates also living there and we hung out together when not working.
Playing rugby for the Sudbury Exiles Rugby Club was a great diversion and we travelled around playing rugby and drinking beer all summer, when not working. That particular summer, there was a strike at INCO. INCO was famous for fractious labour relations and strikes were often a long drawn out, violent, seething exercise. The next day, the strike was on and we were locked in! Only safe way in and out of the mine was by helicopter. A sleeping facility was set up at Coleman Mine, also behind the picket line and a cookhouse was set up at Levack Mine.
During the time, the men outside the picket line threw Molotov cocktails on the lumber yard. A LOT of timber was used underground at that time! Thankfully, the fire was extinguished quickly. There was a particularly ugly incident where somebody, presumably a union guy, shot at one of the helicopters with a rifle! There is a bright future for you at Vale.
Learn more about the opportunities to grow your career with us. Our Sudbury Operations have been in operation for more than years.
With five mines, a mill, a smelter, a refinery and nearly 4, employees it is also one of the largest integrated mining complexes in the world. Our products include nickel, copper, cobalt, platinum group metals, gold and silver. Or, email us at: ontario. To visit our Sudbury Negotiations page, please click here. Learn more here! Vale invites you to learn more about its Emergency Preparedness and Pandemic Response plans here. The materials and products we deliver play a critical role in keeping us and the rest of the world healthy.
0コメント