Bowen (large syncline)

(Map) Bowen mineral coal basin

BOWEN (EN: Bowen; RU: Боуэн), Large syncline, is one of the largest mineral coal basins within Australia, at the south-east of the Queensland state. The area is approximately 75 thousand square kilometres. The reserves of coal, which have been explored, exceed 42 billion tonnes, of them proven and probable reserves are 22.3 billion tonnes, including 13.8 billion tonnes of the coking coals; 3.2 billion tonnes of the coal are accessible for the opencast development. Bowen provides up to 40% of the extraction, and approximately 50% of the export of coal within Australia. There have been explored 36 deposits, the extraction is conducted at 14 of them (Collinsville, Gunella, Peak Downs, Saraj, Blackwater, Likeheart, Cook, Sirius Creek, Southern Blackwater, Baralaba, Moura, Kayanga, Blair Athol, Nibo; see the Map). The coal has been discovered for the first time during the 1827, the development has been started during the 1845, the geological-exploratory works have been started during the end of the 1950-ies, the industrial mastering has been started during the start of the 60-ies.

The Bowen basin is situated within the foredeep of the Hercynides mountains within the New England state. The industrial coal-bearing ability is associated with the stratum of the Permian depositions of the paralic type (more than 5000 metres). The basin represents by itself the synclinorium of the sub-meridional strike, which is complicated by the series of the large synclines and anticlines. The intensity of folding, and the degree of disturbance of the layers, decrease from east to west. The angles of the dip of the layers do not exceed 5-15 degrees. The major coal-bearing stratigraphic suites are Reids-Dome (more than 1000 metres), Collinsville (185-250 metres), Blair Athol (approximately 190 metres), German Creek (170-280 metres), Fair Hill (215-370 metres), Elphinstone, Rangal, Baralaba (40-370 metres).

The quantity of the coal layers within each of the stratigraphic suites ranges from 2 to 11, the working thickness of the layers is from 3 to 28-34 metres. The degree of the regional metamorphism of the coals decreases along the western and south-western directions; within the eastern and north-eastern parts of the basin, there are distributed the semi-anthracites, which are transitioning themselves nearer the north-western periphery into the sub-bituminous coals. The contact metamorphism is associated with the intrusions of granites and granodiorites. The ash content of the most important coal layers is usually 8-25%; at the north of the basin, there exist the coals with the ash content of less than 5%. The moisture of the coals is 1-4.1%, the yield of the volatile substances is 10.7-34.5%, the content of S is at most 0.72%, the R is up to 0.07%.

Within the basin, there work 11 large enterprises (7 open pit mines, and 4 underground mines), while approximately 90% of the extraction is accounted for the opencast developments. The largest company, which is performing the extraction of coal, is the "Central Queensland Coal Association", the 4 open pit mines, which belong to this company, yield more than 16 million tonnes of marketable coal annually. There are being built yet several underground mines and open pit mines. There is used the room-and-pillar system for development, with the excavation by the short-stope combined cutter-loader machines; at the open pit mines, there is used the system for development without the transportation of the waste rocks, with the usage of the powerful draglines. The transportation of the coal is performed by automotive transport. The coking coal, and part of the energetical coal, are beneficiated.

The largest open pit coal mines are: "Peak Downs" with the designed productive capacity of 5 million tonnes of marketable coal, "Gunella", and "Saraj", which are providing almost 1/2 of the annual extraction within Australia (13.5 million tonnes, 1980). Approximately 80% of the coal, which is extracted within the basin, is exported (more than 20 million tonnes during the 1980, 16.5 million tonnes of them are coking coals) through the ports of the High Point and Gladstone cities (the throughput capacity is 20 and 4.5 million tonnes of coal per year), which are connected by railway with Collinsville, Gunella, Blackwater, Baralaba, Moura, and other coal-extracting regions. The distance of the railway transportations is 190-330 kilometres. The main consumer is Japan.