Arckaringa Hills State Heritage Area
LocationThe Arckaringa Hills, north of Coober Pedy, are part of South Australia's arid landscape described as Breakaway Country. Access to this privately-leased region is restricted. The area is extremely fragile and is susceptible to erosion and to irreparable damage from thoughtless or deliberately destructive activities. The boundary of the Arckaringa Hills State Heritage Area encompasses 880 square kilometres of the most scenic region of the Arckaringa Hills. It is approximately 65 kilometres west-south-west of Oodnadatta and includes Mount Arckaringa and a section of the Arckaringa Creek. View Public Notice (250Kb PDF). SignificanceThe Arckaringa Hills State Heritage Area was declared on 20 December 1985, primarily for its geology and exceptional beauty.
Arckaringa Hills, in the region known as the Painted Desert, adds variety to South Australia's outback landscape and is geologically significant as a site illustrating the effects of a prolonged weathering history. The ancient, rugged landscape, once laid down by a vast inland sea, is an isolated South Australian example of terrain known as Badlands or Breakaway topography. It is an area of striking scenic value, with a range of red, brown and yellow bands in the cliff formations. The region is also of biological significance, noted for a number of rare or uncommon plant species and as the southern limits for the distribution of Australia's largest monitor lizard. Geology of the Arckaringa Hills
The Arckaringa Hills provide a unique South Australian example of Breakaway Country or Badlands Topography. The term 'Badlands' was first applied to the arid, dissected plateau of SW Dakota USA, and refers to areas of severe erosion, usually found in semi-arid climates and characterised by countless gullies, steep ridges and sparse vegetation. Badland topography is formed on poorly cemented sediments that have sparse, deeply-rooted plants. Short, heavy showers sweep away surface soil and small plants, creating depressions that gradually deepen into gullies. (source http://reference.allrefer.com ) Because rainfall is low and infrequent, protective crusts known as Duricrusts, tend to form on reasonably flat surfaces. This Duricrust involves cementation of the original material and results in a hard resistant surface, in this case silicrete (cemented by silica). As weathering and erosion take place, these areas of Duricrust protect the underlying strata, but 'break away' on the edges to leave mesas or pedestal rocks. The ancient and richly coloured underlying strata are revealed, creating a cliffline known as Breakaway Country. Each crumbling layer represents a period in geologic history. (source Cadney Homestead Web Site) In South Australia's outback, the erosion of deeply weathered marine and early Cretaceous mudstone and sandstone has produced the picturesque and colourful Breakaway Country of the Arckaringa Hills. The cliffs are an array of coloured strata of red, brown and yellow oxides and hydroxides. Prolonged weathering over time has formed hard, resistant caps, above which is a silicified soil composed of a red jasper matrix referred to as Rousseau Beds. The area also includes fossilised termite burrows. Biology of the Arckaringa Hills
Vegetation in the region is sparse but varied. The upper slopes are dominated by mulga. Cassia and Eremophila shrubs are also common. Most significant is the presence of two rare plant species - Goodenia chambersii and Lepidium strongylophyllum. Australia's largest monitor, and probably the second largest lizard in the world after the Komodo Dragon, is known to visit the Arckaringa Hills foraging rocky outcrops and surrounding areas for small animals, birds, insects and smaller reptiles. The Perentie, Varanus giganteus, occurs across a large area of central Australia but is not common to any particular area. The Arckaringa Hills are recognised as the southern limits of the reptile's distribution. |
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