Friday, April 15, 2011

Uluru


Uluru
Uluru ( /ˌuːluːˈruː/), also known as Ayers Rock, is a large sandstone rock formation in the southern part of the Northern Territory, central Australia. It lies 335 km (208 mi) south west of the nearest large town, Alice Springs; 450 km (280 mi) by road. Kata Tjuta and Uluru are the two major features of the Uluu-Kata Tjua National Park. Uluru is sacred to the Pitjantjatjara and Yankunytjatjara, the Aboriginal people of the area. It has many springs, waterholes, rock caves and ancient paintings. Uluru is listed as a World Heritage Site

Description

Uluru is one of Australia's most recognisable natural icons. The world-renowned sandstone formation stands 348 m (1,142 ft) high (863 m/2,831 ft above sea level) with most of its bulk below the ground, and measures 9.4 km (5.8 mi) in circumference. Both Uluru and Kata Tjuta have great cultural significance for the Aangu Traditional landowners, who led walking tours to inform visitors about the local flora and fauna, bush foods and the Aboriginal dreamtime stories of the area.

Uluru is notable for appearing to change colour as the different light strikes it at different times of the day and year, with sunset a particularly remarkable sight when it briefly glows red. Although rainfall is uncommon in this semiarid area, during wet periods the rock acquires a silvery-grey colour, with streaks of black algae forming on the areas that serve as channels for water flow.

Kata Tjuta, also called Mount Olga or The Olgas, is another rock formation about 25 km (16 mi) west of Uluru. Special viewing areas with road access and parking have been constructed to give tourists the best views of both sites at dawn and dusk.

Geology

Uluru is an inselberg, literally "island mountain", an isolated remnant left after the slow erosion of an original mountain range. Uluru is also often referred to as a monolith, although this is a somewhat ambiguous term that is generally avoided by geologists. The remarkable feature of Uluru is its homogeneity and lack of jointing and parting at bedding surfaces, leading to the lack of development of scree slopes and soil. These characteristics led to its survival, while the surrounding rocks were eroded.[6] For the purpose of mapping and describing the geological history of the area, geologists refer to the rock strata making up Uluru as the Mutitjulu Arkose, and it is one of many sedimentary formations filling the Amadeus Basin.

Age and origin

The Mutitjulu Arkose is believed to be of about the same age as the conglomerate at Kata Tjuta, and to have a similar origin despite the rock type being different, but it is younger than the rocks exposed to the east at Mount Conner, and unrelated to them. The strata at Uluru are nearly vertical, dipping to the south west at 85°, and have an exposed thickness of at least 2,400 m (7,900 ft). The strata dip below the surrounding plain and no doubt extend well beyond Uluru in the subsurface, but the extent is not known. The rock was originally sand, deposited as part of an extensive alluvial fan that extended out from the ancestors of the Musgrave, Mann and Petermann Ranges to the south and west, but separate from a nearby fan that deposited the sand, pebbles and cobbles that now make up Kata Tjuta.[5][6] The similar mineral composition of the Mutitjulu Arkose and the granite ranges to the south is now explained. The ancestors of the ranges to the south were once much larger than the eroded remnants we see today. They were thrust up during a mountain building episode referred to as the Petermann Orogeny that took place in late Neoproterozoic to early Cambrian times (550-530 Ma), and thus the Mutitjulu Arkose is believed to have been deposited at about the same time. The arkose sandstone which makes up the formation is composed of grains that show little sorting based on grain size, exhibit very little rounding and the feldspars in the rock are relatively fresh in appearance. This lack of sorting and grain rounding is typical of arkosic sandstones and is indicative of relatively rapid erosion from the granites of the growing mountains to the south. The layers of sand were nearly horizontal when deposited, but were tilted to their near vertical position during a later episode of mountain building, possibly the Alice Springs Orogeny of Palaeozoic age (400-300 Ma).

History

Archaeological findings to the east and west indicate that humans settled in the area more than 10,000 years ago.[10] Europeans arrived in the Australian Western Desert in the 1870s. Uluru and Kata Tjuta were first mapped by Europeans in 1872 during the expeditionary period made possible by the construction of the Australian Overland Telegraph Line. In separate expeditions, Ernest Giles and William Gosse were the first European explorers to this area.

While exploring the area in 1872, Giles sighted Kata Tjuta from a location near Kings Canyon and called it Mount Olga, while the following year Gosse observed Uluru and named it Ayers Rock, in honor of the Chief Secretary of South Australia, Sir Henry Ayers. Further explorations followed with the aim of establishing the possibilities of the area for pastoralism. In the late 19th century, pastoralists attempted to establish themselves in areas adjoining the South western/Petermann Reserve and interaction between Aangu and white people became more frequent and more violent. Due to the effects of grazing and drought, bush food stores became depleted. Competition for these resources created conflict between the two groups, resulting in more frequent police patrols. Later, during the depression in the 1930s, Aangu became involved in dingo scalping with 'doggers' who introduced Aangu to European foods and ways.

Tourism

The development of tourism infrastructure adjacent to the base of Uluru that began in the 1950s soon produced adverse environmental impacts. It was decided in the early 1970s to remove all accommodation-related tourist facilities and re-establish them outside the park. In 1975, a reservation of 104 square kilometres (40 sq mi) of land beyond the park's northern boundary, 15 kilometres (9 mi) from Uluru, was approved for the development of a tourist facility and an associated airport, to be known as Yulara. The camp ground within the park was closed in 1983 and the motels closed in late 1984, coinciding with the opening of the Yulara resort. In 1992, the majority interest in the Yulara resort held by the Northern Territory Government was sold and the resort was renamed Ayers Rock Resort.

Since the park was listed as a World Heritage Site, annual visitor numbers rose to over 400,000 visitors by the year 2000.[19] Increased tourism provides regional and national economic benefits. It also presents an ongoing challenge to balance conservation of cultural values and visitor needs.

Climbing

Climbing Uluru is a popular attraction for visitors. A chain handhold added in 1964 and extended in 1976 makes the hour-long climb easier, but it is still a long (800 m/0.5 mi) and steep hike to the top, where it can be quite windy. It is recommended individuals drink plenty of water whilst climbing, and those who are unfit, suffer from vertigo or medical conditions restricting exercise, do not attempt it. Climbing Uluru is generally closed to the public when high winds are recorded at the top. There have been at least 35 deaths relating to recreational climbing since such incidents began being recorded.

The local Aangu do not climb Uluru because of its great spiritual significance. They request that visitors do not climb the rock, partly due to the path crossing a sacred traditional Dreamtime track, and also due to a sense of responsibility for the safety of visitors. The visitors guide says "the climb is not prohibited, but we prefer that, as a guest on Anangu land, you will choose to respect our law and culture by not climbing

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