Fimiston Open Pit mine (Super Pit gold mine), Kalgoorlie Consolidated Gold Mines, Kalgoorlie-Boulder, Kalgoorlie-Boulder Shire, Western Australia, Australiai

Regional Level Types
Fimiston Open Pit mine (Super Pit gold mine)	Mine
Kalgoorlie Consolidated Gold Mines	Group of Mines
Kalgoorlie-Boulder	- not defined -
Kalgoorlie-Boulder Shire	Shire
Western Australia	State
Australia	Country

Officially named as The Fimiston Open Pit Mine but also known as the Super Pit, is the largest open cut gold mine in Australia.
It is also Australia's largest producer of gold, with an output of nearly 21 tonnes (almost 0.68 million ounces) (http://www.dfat.gov.au/facts/resources_sector.html).


When prospector Patrick (Paddy) Hannan discovered gold here in 1893, it was the culmination of a series of large gold discoveries in the early 1890's in Western Australia. The discovery led to another inevitable gold rush. When the surface gold became exhausted, a concentrated area of large gold mines developed which became known as The Golden Mile,directly east of present day Kalgoorlie-Boulder. It is claimed by some to be the richest square mile of earth on the planet.

By the late 1890's, the discovery of deep gold reefs, led to the formation of companies to mine the gold, financed largely by British speculators. The Great Boulder Mine is considered the first large scale mine on The Golden Mile, but there were dozens of leases and mines. Later the Fimiston Mine became paramount.

When the writer visited in 1980, the area was littered with poppet heads, historic buildings, and rusting old mine machinery, now sadly all gone. At the southern end was huge white plateaus, known locally as 'The Slime Dumps', being mullock from the many leases on the field. It ended up being processed four times, as improvements in technology allowed more gold to be won from re-processing the material.

Around 1989, colourful Western Australian entrepreneur, Alan Bond, began buying the many individual leases, with the hope of creating one large scale mine covering the entire Golden Mile. In the middle of the field was the historic Boulder Block Hotel. For many years the publican could not understand how bottles of scotch were going missing from the cellar. Meanwhile, at the mine next door, the mine manager couldnt understand how miners were entering the mine sober and leaving drunk. This went on for many years, until one day the publican caught the miners red handed tunnelling into the cellar. The owners in 1989 refused to sell the hotel, until an offer was eventually made of 3 million dollars (Aust). The hotel was dismantled with the promise it would be rebuilt elsewhere in Kalgoorlie. The hotel was then lost, and no-one to this day knows where it is.

When Alan Bond hit liquidity problems, Kalgoorlie Consolidated Gold Mines(KCGM) was formed, completing the task of consolidating all the leases. A huge open pit mine could now be developed covering the entire Golden Mile. KCGM now manages the mines for Newmont Mining Corporation and Barrick Gold Corporation. The gold is not visible to the naked eye, and is processed in the Gidji Roaster, north of the town, to extract the precious metal.

The Kalgoorlie goldfield has over 1000 lodes, stretching 5 kms long by up to 2 kms wide and to 1 km deep, controlled by a complex series of brittle-ductile shear zones, clustered in a geometric array on both sides of the steeply north-west to north north-west dipping Golden Mile Fault, which cuts across the middle of the field through the Golden Mile dolerite, and a lesser extent the Paringa basalt. The entire field is surrounded by an envelope of chlorite-calcite alteration, replacing metamorphite actinolite and albite in all the mafic rocks.

Two major structures have been identified. The Fimiston lode is a steeply dipping shear zone roughly parrallel to the main Golden Mile Fault, as an east-west lode system on the flanks of the Kalgoorlie Syncline. It is composed of breccia bodies and cavity filled veins surrounded by an inner zone of sericite-ankerite-siderite-quartz-hematite-pyrite and telluride alteration zones and contain most of the gold; and an outer zone of ankerite-sericite-quartz-pyrite where chlorite and calcite has progressively replaced the ore mineralisation. It contains free native gold often associated with arsenical pyrite, and much Au-Ag-Hg-Pb telluride mineralisation. The Fimiston Lode can be subdivided into the Eastern Lode, a swarm of smaller lodes, and the West Lode which is less complex, more persistent, and better defined.

The second structure is the Oroya Lode of green vanadian muscovite, ankerite, quartz, pyrite, native gold and gold-silver tellurides. The lode is controlled by the 50 degree west dipping reverse Oroya Shear Zone system.

The Super Pit is approximately 3.7 kms long by 1.55kms wide and more than 660m deep. At present the life of the mine is 2018, and KCGM is actively looking for ideas as to what the local community can do with a gigantic hole next to their town, once the mine closes. Visitors can look out over the Super Pit from a viewing platform, and tours are taken into the mine. KCGM have a shop in the main street of Boulder which sells gold from the mine. There are many mining and mineral specimen related tourist attractions in Kalgoorlie and the surrounding region. Gold nuggets from the Golden Mile would normally be before the Super Pit became operational, and are usually labelled from the former mine they came from. Sometimes non gold specimens are labelled 'Kalgoorlie' or 'The Golden Mile', but many come from the surrounding region, and were labelled such as the nearest recognisable place.

More geology information under 'Kalgoorlie-Boulder', and 'Golden Mile Mine' Mindat localities.

Other Regions, Features and Areas containing this locality

References