AT THE POINT
Location: The confluence point is on the eastern edge of the Barkly Tableland in western Queensland, approximately 30km west of the Waggoobunyah Range. A dirt track, which is accessible via the Barkly Highway to the south-west, comes within 3 km of the confluence. The remaining distance was traversed by 4WD across country in May 2008 by an expedition of RGSQ members. The nearest settlements are Gunpowder, 50 km to the north-east and Mt Isa is 95km to the south-east. The point lies within the Mt Isa City local government area.
The Landscape: The location is predominately flat terrain with an elevation of approximately 315 m. The geology at the point is sand and gravel regolith of Quaternary age (less than 1.6 million years). Drainage flows to the west with Saga Creek, 2km to the north, the closest watercourse. It flows to Inca Creek and eventually the Buckley River, 30 km to the south-west. The Buckley River joins the Georgina River, part of the Lake Eyre Basin catchment, just inside the Northern Territory border.
Vegetation around the point is low scrub dominated by wattles and spinifex grasses.
Point information and photos: Paul Feeney
IN THE DEGREE SQUARE
The Country: The square occupies the eastern edge of the Barkly Tableland which gives way to the broken country of the Waggoobunya Range in the east. Elevations range from close to 500m ASL in the Waggoobunya Range to around 200m ASL in the west and north. The Waggoobunya Range is heavily folded, faulted and dissected producing a very rugged landscape.
Section of the Waggoobunya Range south of Gunpowder (Google Earth image)
The square straddles the low divide between the waters that flow north to the Gulf of Carpentaria through streams such as Gunpowder Creek and West Thornton Creek; and those that flow to the Lake Eyre Basin including the Buckley River.
The geology of the area is very complex with much of the eastern half of the square being composed of sandstone, quartzite and granite of Statherian age (1800 to 1600 million years) while the western half is a complex mixture of rocks ranging in age from siltstone and limestone of Middle Cambrian age (around 510 million years); claystone of Early Cretaceous age (146 to 100 million years) to areas of lateritic duricrust of Cainozoic age (less than 66 million years) and regolith of Quaternary age. The mineral resources of the older formations have been explored and mined for many years with copper, silver and lead being mined in locations such as the Mount Gordon mine near Gunpowder.
Vegetation across the square is generally sparse with spinifex the most common ground cover. Mitchell grass is the main ground cover in the west.
The Climate: The climate of the area is classified as grassland with a winter drought. The nearest climate station operated by the Bureau of Meteorology is at Camooweal Township 92km west of the point.
Camooweal Township (037310) 1891 to the present (elevation 231m ASL)
The highest temperature ever recorded in Camooweal was 46.6oC in December 1990 while the lowest temperature was -2.2oC in June 1971. Rainfalls also vary greatly. The highest rainfall total recorded was 592.8mm in 1974 and the lowest was a total of 80.2mm in 1947.
Extremes of Nature: The area is not highly prone to the impact of cyclones in spite of its tropical location however since 1906 the Bureau of Meteorology database records 17 such storms having passed within 200km of the point. No cyclones have passed within 50km. Even distant cyclones can produce destructive winds and intense rainfall that can lead to localised flooding. Some properties may be isolated for periods of a week or more by flood waters.
Cyclone tracks that passed within 200 km of the point since 1906 (Bureau of Meteorology web site)
The area experiences between 40 and 50 thunder days per year. Severe thunderstorms can bring destructive winds, intense rainfall that can produce flash flooding and lightning. Storms in the dry winter period can spark bushfires if there is sufficient fuel to promote spread.
Extreme heat is also a serious issue. The climate records for Camooweal show that on average (over 71 years of records) the area experiences 155 days a year with temperatures over 35oC and 36 days a year with temperatures over 40oC. Such extreme temperatures can cause heat stroke and death if appropriate measures are not taken such as avoiding strenuous physical effort, keeping as cool as possible and drinking lots of water. Heat waves kill more people in Australia than all other natural hazards combined.
The National Earthquake Database maintained by Geoscience Australia contains no record of any earthquakes within the degree square since 1900.
The Indigenous Story: Much of the land within the degree square is the traditional country of the Wakabunga people.
MORE INFORMATION WELCOME
European Exploration and Settlement: The first Europeans to enter the area were probably pioneering pastoralists in the period between 1860 and 1880. They were followed by prospectors in the 1880s following the discovery of rich copper deposits in the surrounding areas. Several small-scale mines were established in the Waggoobunya Range area that remained active up until the early 1900s. The last major mining operation was at Gunpowder, variously known as Mt Gordon or Mammoth, which was first exploited in 1927. The major period of mining operations was between 1968 and 1977. For a period the township and its water supply Lake Waggaboonya were operated as a tourist resort but that closed in the late 1990s when a new processing operation began at the mine.
MORE INFORMATION WELCOME
The total population of the degree square at the 2011 national Census was 447. The decline in population between 2001 and 2006 was probably associated with the fortunes of the Gunpowder mine.
Mount Isa, with the mine area just to the west of the town (Google Earth image)
Land use across the square is still dominated by cattle grazing though mining and mineral exploration activities probably accounts for the largest amount of economic activity. Much of the 665km of public roads and the water supply infrastructure within the square, including Lake Waggaboonya and the Matador Dam and associated pipelines, has been developed to support the mining industry. This includes a network of slurry pipelines that carry copper concentrate from the Gunpowder and other mines to the Mt Isa smelters.
The square is almost completely contained within Mt Isa City. There are no national parks within the square.
Compilers: Jo Grant and Ken Granger 2010
Edited: Hayley Freemantle
References: various web sites including local governments, QPWS and Bureau of Meteorology.
EPA 2001: Heritage trails of the Queensland outback, Queensland Environmental Protection Agency, Brisbane.
Colin Hooper, 2006: Angor to Zillmanton - stories of North Queensland's deserted towns, Bolton Print 6th edition.