The Leigh Creek Coalfield

The hard brown (sub-bituminous) coal found in the Leight Creek Coalfield was formed by the burial and alteration of plant remains, which accumulated in the area during the Late Triassic period (about 200 million years ago).
The coal contains about 33% moisture, 10 to 20%, ash, and yields about 14 to 17 megajoules per kilogram when burnt.
Due to the presence of salts in the coal, special burners are used to cope with the fouling properties of the coal.

The coal occurs in four small isolated lobes or basins.
These lobes are probably remnants of a formerly more extensive sequence of sedimentary rocks deposited in lakes and river systems.

Lobe A: No mining is envisaged at this stage
Lobe B: This contains about 500 million tonnes of coal, of which a total of about 110 million tonnes will be mined.
Lobes C & D: These basins have been mined out.

Lobe B, or the Telford Basin, is a saucer-shaped basin containing a coal-bearing sequence about 1000 metres thick.
The coal occurs in three zones: Lower, Main and Upper Series.

Mining of coal on a large scale began at Lobe B in 1943.
Operations were transferred in 1956 to the smaller but more easily worked deposits in Lobes C and D.
When these were mined out, operations returned to Lobe B in 1976.

In an over a twenty-year period up until 2001, about 80 million tonnes of coal had peen mined from the coalfield and used at the Port Augusta power stations.
A further 60 million tonnes will be extracted from Lobe B to a maximum depth of 200 metres by 2025.

Up to 2025, extraction of about 3 million tonnes of coal per year will require the removal of about 28 million tonnes of overburden per year, with most of the overburden being dumped back into the open cut.

The Upper Series open cut will then be up to 150 metres deep and about 700 metres wide.
The final depth of the Main Series open cut will be up to 200 metres.

The Upper and Lower Series contain numerous coal seams, interbedded with mudstone, siltstone and sandstone.
The open cut allows extraction of coal from the Upper Series seams.
The Upper Series accounts for approximately one-third of coal produced at Leigh Creek.

The Main Series consists of a thick single seam, which varies from 10 to 20 metres in thickness.
The coal dips at 15° in the Main Series and 30° in the Upper Series.
The coal is overlain by 10 metres of alluvium.

Overburden is broken by blasting rock in benches 7 to 15 metres high.
Large electric shovels and 240 tonne trucks remove the overburden material and dump it back into areas where coal has already been extracted.
Some of the overburden was used to construct a retention dam to prevent flooding by Leigh Creek.

Once the coal is exposed, bulldozers clean overburden off the top of the coal.
The coal is mined by front-end loader or hydraulic excavator and loaded into trucks for hauling to the crushing plant.

After being broken to less than 200 mm, the coal is crushed to less than 38 mm and stored in large bins.
Special trains haul about 10'200 tonnes in 161 wagons to Port Augusta.

This tyre achieved 289'215 km and 17'520 hours in service.
When removed on 31 May 1988 this was a world record for this type of tyre.

Manufacturer: Bridgestone
Tyre data:
Serial No. S1JZN4053
Size - 36.00 x 51
Ply Rating - 58
Type - RLS, Tubeless, Earthmover Inflation Pressure - 90 PSI
Nominal Mass (New and on Rim) - 3.5 tonne

This type of tyres was used on Titan 33-15B Overburden Haulers with unladen weight 120 tonne and nominal payload 154 tonne.
During the period this tyre was fitted, the particular hauler would have carried about 8 million tonne of overburden.

The rocks in the enclosure, mined from a depth of between 30 - 40 metres, are thought to be around 230 million years old.

In the culture of the local Adnyamathanha Aboriginal People, all places are linked through the muda (creation of the land).
Through the muda, different characters in human and animal form create and shape the Adnyamathanha environment.

Wadu (a long time ago), Yulu the kingfisher lit a large signal fire to tell the people at Ikarra (Wilpena Pound) that he was coming to visit from the north.
The coals of this fire became the coal deposit now mined at Leigh Creek.

While Yulu's fire burnt, the kingfisher decided to cook mai (damper) in the coals.

The rocks represent remains left behind by Yulu.
The fossilised wood is the fire sticks used to start the signal fire, and the round rocks are the dampers cooked in the fire by Yulu.



No liability for timeliness, integrity and correctness of this document is accepted.
Last updated: Friday, 04.06.2010 1:21 PM