Uluru, also known as Ayers Rock
Ayres rock Uluru, also referred to 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 (The
Olgas) and Uluru are the two major features of the Uluru
- Kata Tjuta 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.
The local Pitjantjatjara people call the landmark Uluru
. This word has no particular meaning in their dialect,
also known as Pitjantjatjara, but it is also used as
a local family name by the senior Traditional Owners
of Uluru.
On 19 July 1873, the surveyor William Gosse visited
Uluru and named it Ayers Rock in honour of the then-Chief
Secretary of South Australia, Sir Henry Ayers. Since
then, both names have been used, although Ayers Rock
was the most common name used by outsiders until recently.
In 1993, a dual naming policy was adopted that allowed
official names that consist of both the traditional
Aboriginal name and the English name.
On 15 December 1993, it was renamed "Ayers Rock/Uluru"
and became the first officially dual-named feature in
the Northern Territory. The order of the dual names
was officially reversed to "Uluru/Ayers Rock" on 6 November
2002 following a request from the Regional Tourism Association
in Alice Springs.
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 Anangu Traditional landowners, who lead 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 owing
to its peculiar formation, is another rock formation
about 25 km (16 mi) from 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.
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 because of its multiple meanings, and thus a word
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. 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.
Uluru is dominantly composed of coarse-grained arkose,
a type of sandstone characterized by an abundance of
feldspar, and some conglomerate.
Average composition is 50% feldspar, 25-35% quartz
and up to 25% rock fragments; most feldspar is K-feldspar
with only minor plagioclase as subrounded grains and
highly altered inclusions within K-feldspar. The grains
are typically 2-4 millimetres (0.079-0.16 in) in diameter,
and are angular to subangular; the finer sandstone is
well sorted, with sorting decreasing with increasing
grain size.
The rock fragments include subrounded basalt, invariably
replaced to various degrees by chlorite and epidote.
The minerals present suggest derivation from a predominantly
granite source, similar to the Musgrave Block exposed
to the south.
When relatively fresh, the rock has a grey colour,
but weathering of iron-bearing minerals by the process
of oxidation gives the outer surface layer of rock a
red-brown rusty colour. Features related to deposition
of the sediment include cross-bedding and ripples, analysis
of which indicated deposition from broad shallow high
energy fluvial channels and sheet flooding, typical
of alluvial fans.
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. 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 later tilted to their near vertical position
during a later episode of mountain building, possibly
the Alice Springs Orogeny of Palaeozoic age. Historically,
46 species of native mammals are known to have been
living in the Uluru region; according to recent surveys
there are currently 21.
Anangu acknowledge that a decrease in the number has
implications for the condition and health of the landscape.
Moves are supported for the reintroduction of locally
extinct animals such as Malleefowl, Common Brushtail
Possum, Rufous Hare-wallaby or Mala, Bilby, Burrowing
Bettong and the Black-flanked Rock-wallaby.
The Mulgara, the only mammal listed as vulnerable,
is mostly restricted to the transitional sand plain
area, a narrow band of country that stretches from the
vicinity of Uluru to the Northern boundary of the park
and into Ayers Rock Resort. This area also contains
the marsupial mole, Woma Python and Great Desert Skink.
The bat population of the park comprises at least seven
species that depend on day roosting sites within caves
and crevices of Uluru and Kata Tjuta. Most of the bats
forage for aerial prey within 100 m (330 ft) or so from
the rock face.
The park has a very rich reptile fauna of high conservation
significance with 73 species having been reliably recorded.
Four species of frog are abundant at the base of Uluru
and Kata Tjuta following summer rains.
The Great Desert Skink is listed as vulnerable. Anangu
continue to hunt and gather animal species in remote
areas of the park and on angu land elsewhere.
Hunting is largely confined to the Red Kangaroo, Bush
Turkey, Emu and lizards such as the Sand Goanna and
Perentie. Of the 27 mammal species found in the park,
six are introduced: the House Mouse, camel, fox, cat,
dog and rabbit. These species are distributed throughout
the park but their densities are greatest in the rich
water run-off areas of Uluru and Kata Tjuta. Uluru -
Kata Tjuta National Park flora represents a large portion
of plants found in Central Australia.
A number of these species are considered rare and
restricted in the park or the immediate region. There
are many rare and endemic plants at Uluru and Kata Tjuta.
The growth and reproduction of plant communities rely
on irregular rainfall. Some plants are able to survive
fire and some are dependent on it to reproduce.
Plants are an important part of Tjukurpa, and there
are ceremonies for each of the major plant foods. Many
plants are associated with ancestral beings.
Trees such as the Mulga and Centralian Bloodwood are
used to make tools such as spearheads, boomerangs and
bowls. The red sap of the bloodwood is used as a disinfectant
and an inhalant for coughs and colds. There are several
rare and endangered species in the park. Most of them,
like Adder's
Tongue ferns, are restricted to the moist areas at
the base of the formation, which are areas of high visitor
use and subject to erosion. Since the first Europeans
arrived, 34 exotic plant species have been recorded
in the park, representing about 6.4% of the total park
flora.
Some, such as perennial buffel grass (Cenchrus ciliaris),
were introduced to rehabilitate areas damaged by erosion.
It is the most threatening weed in the park and has
spread to invade water- and nutrient-rich drainage lines.
A few others, such as burrgrass, were brought in accidentally,
carried on cars and people.
Footnote Text Courtesy Of: http://wikitravel.org/
Footnote Photographs Courtesy Of: NTTC
- Northern Territory Tourism Commission
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