Friday Eco-Fact: The Meteorites of the Nullarbor

The Nullarbor Plain is a spectacular place holding may treasures for those who would look. Among its claims to fame is its reputation as one of the world’s richest sources of meteorite specimens:

A Desert plain in Australia may become the world’s largest source of meteorites, according to preliminary surveys which have already recovered more than 1000 fragments of stones and lumps of iron from space. The fragments are of about 150 meteorites that fell up to 20 000 years ago. An initial analysis of the fragments suggests that the proportions of different kinds of meteorite have changed significantly over the millennia.

The new source of meteorites is the Nullarbor Plain, an area of limestone that stretches for 600 kilometres along the south coast of Western Australia and South Australia. Alex Bevan, of the Western Australian Museum in Perth, has been leading the search for meteorites in this region. He says it is unusually easy to find meteorites on the plain, because the pale smooth limestone pavement provides a perfect background for spotting the meteorites, which are dark brown or black. In addition, the barren plain has very little vegetation to cover up the meteorites (its name comes from the Latin nulla arbor, meaning no trees).

The aridity of the Nullarbor Plain has not only made meteorites easy to spot, but it has also prevented rain and chemical reactions from eroding them. There is no shifting sand to cover them, as there would be in other desert regions. ‘We can pick them up from the surface just where they fell,’ says Bevan, ‘possibly as long as 16 000 to 18 000 years ago, when the region began to experience severe aridity.’ [New Scientist]

Read the rest of the article but it goes on to explain how the Nullarbor has gone on to replace Antarctica as the top place to look for meteorite fragments. Some of these fragments are especially large. For example one fragment, found in 1966 near Mundrabilla Siding, WA, weighed in at an incredible 11 tonnes.

You can see my own pictures of the Nullarbor Plain here and here.