Ayers Rock and the Olgas

Uluru or Ayers Rock, is a large sandstone rock formation located 450km (280 mi) away from Alice Springs in the middle of the Australian Outback.

Officially, the rock has a dual place name of Uluru / Ayers Rock.

The rock is a holy place for the Anangu tribe of Aboriginal people in Australia who have been in the area for around 10,000 years.

The first foreign people to see Uluru were explorers led by English born Australian William Christie Gosse, his group set eyes on Uluru, 19 July 1873 and decided to call it Ayers Rock after Sir Henry Ayers, the Chief Secretary of South Australia at the time.

Uluru is estimated to be around 600 million years old, it originally would have sat at the bottom of a sea, but today it stands 348 m (1,142 ft) above the flat desertand 863 m (2,831 ft) above sea level.

Amazingly, some 2.5km's of Uluru's mass is believed to be underground.

The average geological composition of Uluru is 50% feldspar, 25-35% quartz and up to 25% rock fragments.

The Uluru formation is 3.6 km (2.2 mi) long, 1.9 km (1.2 mi) wide and has a circumference of 9.4 km (5.8 mi) covering 3.33 km² (1.29 mi²).

Uluru is an inselberg (meaning island mountain), which is a prominent isolated bump or hill that rises abruptly from widespread flat plains in a hot, dry region. Its the hard rock of a mountain left over after softer areas have eroded away. Uluru is also often called a monolith, which is more of a vague geological term.

The rock has eroded valleys and ridges and little or no vegetation. The surrounding area however, has a number of springs, waterholes, rock caves, and ancient paintings.

The striking orange-red hue color of Uluru is due to surface oxidation of its iron content, otherwise the formation would look more grey.

Uluru was originally listed on the natural World Heritage site in 1987 due to its unique geology. In 1997, it was also put on the World Heritage site list as a cultural site due to its importance to the local Aborigines. The rock is one of the few places in the world to have two listings.

Uluru is not the only rock formation in the area. Kata Tjuta also known as Mount Olga (or The Olgas) is a group of 36 large dome shaped rocks (originally being one massive monolith) located 25km (16mi) West of Uluru in the Northern Territory. The tallest of which is 546 m (1,791 ft). Uluru and Kata Tjuta are two major landmarks within the Uluru-Kata Tjuta National Park.

http://www.sciencekids.co.nz/sciencefacts/earth/uluru.html