The Diamond Hill Mine is an underground gold mine located approximately 45 air kilometers (28 air miles) southeast of Helena, Montana. The mine is in Broadwater County and on the east flank of the Elkhorn Mountains, within the Hassel Mining District.
Since production commenced in 1996, Diamond Hill has mined over 775,000 tons at an average grade of 0.233 ounces per ton gold. During 1998, Diamond Hill Mining achieved a record annual production of over 240,000 tons.
As of December 31, 2000 Diamond Hill Mining reports a mineral resource of 233,312 tons at an average grade of 0.215 ounces per ton gold in all categories.
The Diamond hill ore bodies and mine workings are in exceptionally solid unfractured rock and accordingly are amenable to low cost sublevel open stoping methods. Ore is transported to the Montana Tunnels mill facility by truck. There it is processed in a separate circuit designed for Diamond Hill ore. Most gold is recovered into a high grade pyrite concentrate and sold to Japanese smelters.
The mine is located in volcanic rocks adjacent to the Boulder Batholith, a dominant igneous intrusion which also hosts the famous Butte Copper mining district. The deposit is classed as a skarn hosted sulfide deposit where the predominant ore mineralogy is gold associated with pyrite and lesser other metal sulfides.
The hanging wall is composed of andesite and the footwall of diorite. The contacts are irregular. The rock is competent.
Mineralized zone is composed of calcite skarn.
There are no visual contact limits for grade control. The structure has to be drilled and assayed in order to determine the economical ore limit.
The deposit is split into four satellite zones. Although the orebody is irregular in shape, it is continuous along its depth.
Skarn deposit (4 mining areas): North zone, Glory Hole zone, Debeers and Facet.
The ore is located along a fault. Each zone has a short length strike and longer top to bottom extension. The entire deposit has 457 m (1500 ft) of extension and 305 m (1000 ft) from top to bottom.
Gemcom is used to compile geological data.
Executive staff: 9 company employees, 4 temporary employees.
Mining contractor: 25 to 30 underground workers.
Hauling done by Mungus contractor: 6 to 8 people. The milling is also contracted
The Galena Mine, an underground silver mine, is located approximately 5 km (3 mi) from Wallace, Idaho in the heart of Shoshone County commonly called the Silver Valley. The Galena Mine property consists of approximately 4.45 square kilometres (1,100 acres) in Lake Gulch.
The mine used the cut-and-fill mining method, with sand backfill, to extract ore from high-grade silver-copper vein deposits.
The near-surface geology is Precambrian Belt rocks. The principal minerals in the veins are siderite, quartz, tetrahedrite, chalcopyrite, and pyrite.
The vein has an average thickness of 1 to 1.2 m (3 to 4 ft). However, the mining width varies between 1.8 to 2.4 m (6 to 8 ft). Generally, the zone is continuous and the follow-up in the stope is not a concern. Each excavated lift is mapped by the geology department. These sketches are sufficient to guide the work supervised by the supervisors.
Length: 610 m (2000 ft).
Depth: 1676 m (5500 ft).
Dip: 65 to 75 degrees.
Executive staff: 39, including mill.
Milling plant: 8.
The mine normally operated three, 8-hour-shifts a day, five days a week.
The K-2 deposit is located approximately 5 km (3 mi) west of the town of Curlew, in the northern portion of Ferry County, Washington, U.S.A.
DESCRIPTION OF THE DEPOSIT
K-2 is a volcanogenic hot springs epithermal deposit within the Tertiary Sanpoil volcanics near the western margin of the Republic Graben. The Sanpoil volcanics host the productive epithermal gold veins of the Republic district to the south and recently mined Kettle deposit to the east. The discovery of K-2 in 1990 was based upon anomalies of up to 1257 ppb gold in stream sediment sampling.
Mineralization occurs along a north-northwest trending structural zone which extends along strike for approximately 762 m (2500 ft) and down dip for approximately 244 m (800 ft). This mineralized zone generally dips to the east at 60 to 75 degrees and consists of quartz, quartz-calcite and calcite veins. Zones of mineralized veins and vein breccias can range up to 21 m (70 ft) wide, but are commonly 3.6 m to 4.5 m (12 to 15 ft) in width. The two main ore types at K-2 are quartz vein and quartz stockwork type mineralisation which follow two primary structures with good persistence and continuity. These two structural zones are referred to as the A zone, which is localized along the footwall, and the D zone, which is localized along the hanging wall. Locally some economic quartz stockwork mineralization exists between the A zone and D zone which has been mined with success. Numerous ancillary veins have been identified, but poor continuity makes them uneconomic.
The gold is 100% associated with quartz. The rock has to be sampled in order to obtain the grade.
2 engineers, 2 surveyors, 1 geologist, 1 technician geologist and 1 exploration geologist.
Manpower per shift: 1 long-hole driller, 2 development miners, 1 scooptram operator, 3 truck drivers, 1 shift boss, 2 mechanics/crew and 1 electrician per day.
Work schedule: 6 days per week, 2 shifts of 10 hours per day.
The Kloof gold mine lies approximately 60 km (37 miles) south west of Johannesburg and 20 km (12 miles) from Carletonville, on the border of Hauteng and Northwesdt Provinces, South Africa. Wholly owned by Goldfields Ltd, it consists of three sections, Kloof, Libanon and Leeudoorn, which were amalgamated into one operating division during 2001-2002. The mine operates at depths of 1,000 m to 3,500 m (3280 ft and 11483 ft).
Shaft 4 is actually in development and employs 2000 people. On the other hand, Kloof complex employs 17,000 people (2001).
Kloof lies in the West Wits goldfield, part of the Archaean-age Witwatersrand Basin, between the north-trending Witpoortjie Fault to the east and the Bank Fault to the west. The basin itself consists of a 6 km (3.7 miles) thickness of argillaceous and arenaceous sedimentary rocks within the Kaapvaal Craton. Gold mineralisation is found in quartz pebble conglomerate reefs, the gold generally occurring in native form with pyrite and carbon. Kloof is the highest-grade gold mine in South Africa.
The mineralized zone is easily identifiable by the quartz pebble conglomerate of a few centimetres in diameter, embedded in a gray siliceous cement, often hardened. Only one zone called band is mined. The last developed level is located at a depth of 3600 m (11810 ft).
The vein is fairly continuous; however, the vein can be displaced by faults, or joints, or can even be up-corrugated or down-corrugated.
To deal with ground pressures, a V-shaped mining sequence is utilized (Sequential grid down dip mining).
The main advantages of the sequential down dip method are the very low energy release rates, which make backfilling unnecessary, and the allowance for the physical separation of rock transport from men and materials. However, this has serious implications for ventilation: very large volumes of air are required as it is difficult to keep the airflow close to the face in the absence of backfill; and the return airways have to be cooled as they are used as travelling ways and the air exiting the stope would have gained heat while passing through the worked out areas.
Kundana is situated 25 km (15.5 mi) west-northwest of Kalgoorlie and 27 km (17 mi) north-northwest of Coolgardie in Western Australia.
The Kundana deposits are hosted by a structurally prepared sequence of sediments, volcaniclastics, mafic and ultramafic volcanic and intrusive rocks.
The mineralization is typically comprised of thin, steep to moderately west dipping quartz veins at lithological contacts. The veins range from 5 cm to 2 m (2 in to 6.5 ft) in width and can contain typically several ounces of gold per tonne. Only trace amounts of other metals are contained in the veins. The lodes are up to 500 m (1640 ft) in length and, to date, have been defined down dip to a depth of 600 m (1969 ft).
There are five main orebodies:
- SOUTH LODE
Average width: 1.5 m (5 ft)
Length: 600 m (1969 ft)
Dip: 75 to 85 degrees
Grade: 10 to 15 g/t
Mined by open pit and underground
- NORTH LODE
Length: 400 m (1312 ft)
Dip: 75 degrees
Mined by open pit
- STRZELECKI MAIN ZONE
Average width: 0.7 m (2.3 ft)
Length: 500 m (1640 ft)
Dip: 55 degrees
Grade: 60 to 90 g/t
Mined by open pit and underground
- STRZELECKI HANGING WALL ZONE
Average width: 0.4 m (1.3 ft)
Length: 200 m (656 ft)
Dip: 55 degrees
Grade: 1 to 60 g/t
Mined by open pit and underground
Average width: 0.4 m (1.3 ft)
Length: 600 m (1969 ft)
Grade: 60 g/t
Presently mined by open pit and planning for future underground extraction.
The Lucky Friday mine, a deep underground silver and lead mine, located in northern Idaho and 100% owned by Hecla, has been a producing mine for Hecla since 1958.
The Lucky Friday vein at 1.6 km (1 mile) below surface is an S-shaped vein extending horizontally about 488 m (1600 ft). Splits off the main vein extend the total stoping potential to over 610 m (2000 ft) of strike length. Mineralogically the vein is galena, sphalerite and tetrahedrite in a quartz and siderite gangue. The vein is 0.6 m to 9 m (2 to 30 ft) wide, averaging about 1.5 m (5 ft) wide. The vein is in the Precambrian Revett Quartzite Formation, which hosts most of the Coeur d'Alene District silver-lead producing mines. The Revett Formation varies from extremely competent, massive orthoquartzites to thinly bedded argillaceous incompetent friable members. Argillaceous units vary from several centimetres to few metres (inches to tens of feet) thick.
The vein dips nearly vertical and generally cuts the beds at less than a 10-degree angle. The beds are folded into several small anticlines and synclines with one major anticline forming the center of the S-shaped vein. The vein is bounded on both ends by faults. Numerous small faults cut the vein, the largest of which displaces the vein about 3 m (10 ft).
The Gold Hunter Deposit at the 4900 level is comprised of numerous veins contained within a zone approximately 46 m (150 ft) wide; with the horizontal strike length of the individual veins varying from 61 m to 457 m (200 to 1500 ft). The mining efforts have been concentrated on the "South Vein" dips steeply to the south and is conformable to bedding. The mineralogy of the "South Vein" is predominantly galena, sphalerite and tetrahedrite in a siderite, quartz and barite gangue.The Gold Hunter is hosted by the Precambrian Wallace formation, which accounts for only 5% of the total production from the Coeur d'Alene District. The Wallace Formation consists of thinly bedded argillites and fine grained carbonates.
NUMBER OF EMPLOYEES
42 Underground: 156
Milling plant: 22
The mine is located in Lead, state of South Dakota, USA. This mine has been exploited for 125 years. Through the years, many mining methods were employed. Only two were still used, mechanised cut-and-fill and the long-hole mining methods. As for most mining operations, the price of gold does not allow the operators to exploit the deposit profitably. The closing of operations was planned for the end of the year 2001.
Six major ledges are mined, varying from 914 m (3000 ft) long by 228.6 m (750 ft) wide to 305 m (1000 ft) long by 122 m (400 ft) wide. Within these ledges are irregular shape areas of varying sizes. These ledges dip at approximately 70 degrees to the east and plunge to the south from 15 degrees to 90 degrees.
The lowest mined level is at 2438 m (8000 ft). The vein is still present deeper.
The ore consists of cummingtonite (chlorite schist), which is very competent except for major bedding planes and fracture patterns. The footwall contains slate, but because of the dip, only minor problems were encountered. The hanging wall also contains slate, and because of the dip and the weak bedding, it requires considerable amount of rockbolting.
The continuity of the veins varies throughout the orebody. The structure, consisting of synclinal ledge, tends to pinch and swell.
NUMBER OF EMPLOYEES
Overall staff: 350 employees
Underground: 100 miners working 5 days per week on 3 shifts of 8 hours per day.
The Darlot Mine of the Yilgarn group is located in the Yandal Greenstone belt, 122 kilometers (76 miles) north of Leonora or 680 kilometers (422 miles) northeast of Perth, in western Australia.
There is only one main zone where the centre is massive and the extremities are narrow. The Walters zone is located at a limit. Furthermore, lenses are apparent in the footwall.
The total lenght of the zone is approximately 3700 m to 4560 m (12140 ft to 14960 ft). The Walters zone represents approximately 400 m (1313 ft).
The deepest level is at 600 m (1969 ft). However, in depth exploration is still possible.
Mineralization mainly occurs as disseminated pyrite cubes within bleached-silified-carbonated often haematised selvedges in contact between the country rock and the quartz veins. Free gold is commonly seen. Lamprophyres tend to stope out mineralization.
The country rock in the hanging wall is hosted in magnetized dolorite.
The contact between the mineralized zone and the hanging wall is very regular and easily identifiable. The contact to the footwall is irregular where the mineralization occurs. These contacts are marked by geologists and surveyed to be modelled. The shears are easily identifiable.
The drilling is done following a pattern of 10 m x 10 m (33 ft x 33 ft) pattern. Now that the geology is better understood, the pattern has been increased to 20 m x 20 m (66 ft x 66 ft). Each face is mapped and photographed. The model is generated with the Surpac and Vulcan softwares.
Impala Platinum Limited, Implat’s major operational asset, has its primary operations concentrated on the Impala lease area on the western limb of the world-renowned Bushveld Complex, near the town of Rustenburg in South Africa’s North West Province. Some 28 000 people are employed by Impala Platinum.
Mining at Impala focuses primarily on two reefs, the Merensky Reef and the UG2 Chromitite Layer, which are contained in the Rustenburg Layered Suite, a well-layered ultramafic to mafic igneous succession of the 2 000 million-year-old Bushveld Complex. The majority of mining operations extend to a depth of around 1 000 metres (3280 ft) below surface. Both reefs sub-outcrop on Impala’s property and dip approximately 9-10 degrees towards the centre of the Bushveld Complex, although locally dips may increase to 15 degrees. The mining width, including dilution, for both reef horizons is about one metre (3.3 ft).
Bronzewing, 156 km (97 mi) south of Jundee and 77 km (48 mi) from the township of Leinster, is a relatively new mine. Mining began from a large-scale open pit in 1994 and transitioned to an underground operation in 1997. Currently production comes from two ore bodies, one 500 m (1640 ft) below surface and other at a depth of 402 m (1320 ft). Both are accessed by decline ramps from portals in the open pit. The satellite McClure property, 10 km (6 mi) to the southwest, consists of both open pit and underground operations.
With high-grade ore and a treatment plant handling 2.2 million tons per year, Bronzewing sold 13000 ounces of gold in 2001. Year-end 2001 reserves were 746000 ounces. Underground drilling continues to intersect high-grade extensions in each of the ore bodies.
The mine employs 470 people on a fly-in, fly-out basis.
The deposit contains 2 veins. In the lower levels, one of the veins disappears.
Length of the deposit is approximately 1000 m (3280 ft).
The deposit is very linear with a dip of 70 degrees. A series of inclined dykes at 45 degrees cuts through the deposit.
Jundee Operation is located 45 kilometres (28 miles) northeast of Wiluna and 520 kilometres (323 miles) north of Kalgoorlie in the northern Yandal Belt of Western Australia.
Open pit mining commenced in August 1995 and the first gold was poured in December. Underground development of the Barton Deeps orebodies commenced in August 1997.
Drilling commenced at the adjoining Nimary property (owned by Eagle) in August 1990, with mining commencing in 1995.
The Jundee and Nimary operations were integrated following the takeover of Eagle by Great Central Mines in June 1998.
The Jundee gold zone has a strike and width of approximately 4.0 km (2.5 mi). Mineralisation is hosted within a west-dipping sequence of tholeiitic basalts, with interflow sedimentary units intruded by dolerite sills.
Younger felsic and intermediate porphyries and dolerite dikes intrude the sequence. The mine sequence is bounded to the west by a thick succession of felsic volcanics and volcaniclastics, and mineralisation diminishes eastwards as the mafic package becomes more high-magnesium to ultramafic in composition.
Mineralisation occurs within moderate to steeply dipping brittle-ductile structures which have strike and down dip continuity, and comprise veined and silicified shears, breccias and fracture-fill veins with strong carbonate, silica, sulphide, white-mica and leucoxene alteration.
Jundee, the largest of the Yandal operations, began production in 1995. Ore is currently sourced from a complex of open pits that are approaching depletion and an underground mine.
The mine employs 500 people, whom because of the mine's remote location operates on a two-week on, one-week off, fly-in and fly-out schedule mostly from Perth and Kalgoorlie. A modern full-service village provides on site accommodation.
Underground production commenced from Barton Deeps in late 1998 using the longhole uphole bench method, with levels 20 m (66 ft) vertically apart. Ore is hauled to surface by 50 tonne trucks through a 5.8 m x 5.5 m (19 ft x 18 ft) decline ramp, with the portal in Main Pit.
Ore is treated in two conventional plants, originally designed to treat soft oxide ore. The Jundee CIP plant operates at 1.8 metric tonnes per year processing a blend of open pit oxide and some hard ore. The Nimary CIL plant operates at 1.1 metric tonnes per year. Ore is fed to either plant to provide flexibility and optimise production.
There is only one quartz zone but it is intersected by many faults. In the local mine environment, the reef has an average true thickness of 1.6 m (5.25 ft) and an average dip of 39 degrees to the Southwest. The strike of the reef swings from 153 degrees in the North to 110 degrees in the South. Reef thickness can range from only a few centimetres to over 4 m (13 ft). The South reef can be traced along the surface for approximately 1.6 km (1 mile).
Hanging wall and footwall: Stratigraphic dolerites.
Mineralized zone: A quartz vein with a thickness varying from a few centimetres to 4 m (13 ft). The average width is 1.6 m (5.25 ft).
The contact between the quartz vein and the dolerites is easily visible. The vein pinches and swells in certain areas.
ZONE: GOLDEN AGE REEF
- Length: 20 to 25 m (66 to 82 ft) and a pillar of 3 to5 m (10 to 16 ft) is left.
- Height: 17 m (56 ft) vertical, (20 to 25 m [66 to 82 ft]).
- Width: Average thickness of 1.6 m (5 ft). The vein varies from a few centimetres to 4 m (13 ft).
- Dip: 39 degrees (35 to 40 degrees).
- Distance between levels or sub-levels: 17 m (56 ft) vertical.
- Excellent rock quality.
RMR: approximately 95.
RQD: higher than 80.
Two mining methods used: Long-hole and Room-and-pillar.
Golden Pig mine is located on the western fringe of the wheat belt town of Southern Cross, 360 km east of Perth, Western Australia.
Ultramafic rock of variable composition generally containing tremolite, chlorite and ilmenite with a variable amounts of magnetite and talc in the hanging wall.
Mafic rock, this rock being the most common made typically of hornblende, actinolite, quartz, phlogopite, plagroclase, sphene, imenite in the footwall.
The mineralized zone is of the stratabound type having, as surrounding rock, a formation of banded iron.
Gold grades are associated with pyrrhotite abundance. Visible gold occurs marginal to or enclosed by pyrrhotite or as interstitial grains to silicate gangue minerals, particularly diopside.
The stratigraphy of the deposit is extremely folded with axial planes dipping 70 degrees to the west. The mineralized lodes plunge north at 10 to 15 degrees.
Depth: 8 levels exploited. The deepest part of the mine is 160 m (525 ft).
For stope design, the ore geometry is based on face and drive mapping and diamond drilling. The stope is designed on 20 m (66 ft) sections and wired frame within Surpac. Resources and Reserve calculations are based on block model volumes and length weighted grades for each section.
The deposit is divided into three distinct domains. The one that requires narrow mining is the "North" lens. The geological characteristics are the following:
- Hanging wall: Psammo
- Pelite: The rock competence varies from very weak to very strong depending on the rock type
- Footwall: Ultramafic rock generally very competent Uniaxial Compressive Strength (UCS) = 150 megapascal (MPa)
- The mineralized zone consists in multiple lenses within the Psammo-Pelite zone.
No horizon marker defined but mineralisation is easy to follow.
The vein has good continuity.
Leinster Nickel Operations is located 645 km (400 mi) north-east of Perth, Western Australia.
The main orebody consists of a disseminated sulphide zone with minor, narrow massive sulphide horizons remobilized along its base and internally along structures. The disseminated sulphide zone typically contains between 15% and 45% sulphides, averaging around 2% Nickel. The disseminated sulphide body is typically 200 m (656 ft) in length and up to 75 m (246 ft) in width, with around 50 000 tonnes of ore per vertical metre.
Towards the base of the Perserverance ultramafic complex (PUC) and north of the main lode, tectonic remobilization has led to the formation of the massive sulphide dominated 1A and F2 ore zones. Both represent fault bounded slices with felsic hanging wall stratigraphy. The 1A zone also exhibits prominent ultramafic intersections along its structural footwall which form the source of significant dilution within upper levels of the main lode. The 1A and F2 lodes grade between 5% and 7% Nickel.
The mineralized zone is a massive sulfide of 0.2 m to 5 m (0.65 ft to 16 ft) thick.
The hanging wall sequence, immediately adjacent to the mineralized komatiite flows of the Perseverance orebodies (including the 1A zone), is composed of rhyolitic crystal tuffs which grade westward into intermediate metasediments composed predominantly of variable quantities of quartz-amphibole-biotite.
The footwall to the 1A orebody is a sequence of felsic volcanics that is similar in character and composition to that of the immediate hanging wall rock types. However, these rocks show a higher degree of tectonic strain and are part of a tight fold nose structure that extends into the main disseminated orebody. Therefore, the footwall rock mass is generally more competent and brittle than the immediate hanging wall. Ultramafic material (thickness of 0 to 8 m [26 ft] and more) may be present within and on the immediate footwall of the 1A massive sulphide. This is generally a weak sheared material and has historically been associated with many of the problem areas encountered during open stoping of the 1A orebody.
The vein is a variable but remains easy to follow.
The Miitel Mine is located 55 km (34 miles) by road south of Kambalda in Western Australia. The mine is accessed by 7 km (4 miles) of road from the Coolgardie to Norseman section of the Eyre Highway.
The geology of the Miitel area is typical of the Archaean greenstones which contain most of the gold and nickel mineralization known throughout the region.
These greenstone belts are made up of a variety of rocks which were horizontal when deposited but have since been tilted and folded such that they are now steeply dipping in most areas. Typically the lower part of the greenstone segment is dominated by mafic and ultramafic volcanics with some interflow sulphide sediments and some intrusive dolerites. The upper part of the sequence is dominated by felsic rocks and clastic sediments. The age of the sequence is approximately 2.7 billion years.
In the Kambalda region, nickel orebodies occur in the lower part of the sequence, at the base of the ultramafic volcanic rocks (known as "komatiites") and directly in contact with the underlying basalt unit. This prospective contact runs the full 15 km length of the Miitel tenements and in some areas has been repeated up to three times by early faulting. The Miitel contacts dip steeply to the east.
At the Miitel Mine itself, the orebody occurs as a sheet-like body of sulphides lying on the basalt contact. It consists of three parallel elongated ore zones which dip at about 80 degrees to the east, and plunge at 35 degrees to the south. The central ore zone, known as the NO1, is the largest and highest grade of the three. Its dimensions are approximately 1000 m (3280 ft) along plunge, 50 m to 120 m (164 ft to 394 ft) in dip-direction, and 1 m to 3 m (3.3 ft to 10 ft) thick.
The ore profile Miitel is typical of Kambalda-style komatiite-hosted nickel sulphide orebodies.
The hanging wall consists in an ultramafic rock and the footwall is basalt.
Number of active zones: One.
The top of the orebody is approximately 160 m (525 ft) below the surface and the deepest part is less than 370 m (1214 ft) below the surface. The Miitel shoot has a shallow plunge to the north and slightly steeper to the south.
Miitel has on average 4000 tonnes of ore per vertical metre.
The modified Avoca mining method has been selected to meet the following factors:
- narrow vein
- steeply dipping
- poor quality of the hanging wall
- good productivity
- low mining cost
- extraction from bottom up, this eliminates the need for leaving crown pillars
- tele-remote loading, reducing the exposure of miners.
In 1995, a feasibility study recommended a mechanized cut-and-fill method, with some conventional airleg cut-and-fill on the very narrow lodes. Where ground conditions permitted, an Avoca style up-hole benching method or Alimak long-hole method was recommended.
The Avoca method allows for ground control using a combination of cable bolts and backfill, whilst allowing the extraction of high tonnages in comparison to jumbo cut-and-fill systems. The planned sequencing allows for a consistent extraction rate at a low unit cost in comparison to other narrow vein mining methods.
The Wannaway Mine is located 15 km (9.3 miles) from Miitel which is located 55 km (34 miles) south of Kambalda in Western Australia, or 30 km (18.6 miles) by road, on the other side of the Eyre Highway.
The Wannaway Mine consists of two ore lenses, one of which was largely mined out by WMC during the 1980's and 1990's. The other, known as the NO2, is the subject of current mining operations.
The NO2 ore body is accessed via a 1:7 decline from surface. The ore body is located at a depth of between 300 m (985 ft) and 550 m (1805 ft) below surface. The lode appears to plunge shallowly to the North and dips to the West.
The mineralization is composed of basalt in the footwall and ultramafic rocks in the hanging wall. The ultramafic rocks are talc carbonates and antigorite chlorite. In some areas, a hanging wall shear comprised of lizardite forms the hanging wall to the mineralization. These areas have caused ground problems since the lizardite shear is incompetent. The ore profile is very thin (averaging 2 m [6.5 ft] true thickness) and dominated by the fine grained disseminated sulphides with an average Nickel grade of 3.0% to 3.5%. The massive ore grade averages between 10% and 12% Nickel.
Number of zones: One zone.
Dip: 58 degrees.
Tonnage per vertical meter: 3000 t/vertical meter.
The mine works on a 12-hour day, 7-day week, 3 panel roster, 365 days per year.