Friday, 17 February 2017

The Bungle Bungle Rane in Australia

The Bungle Bungle Range, in Purnululu National Park, is one of the most attractive geological landmarks in Western Australia. The Bungle Bungle range features unique beehive-shaped sandstone towers and conglomerates alternately striped in black and orange bands. The Bungle Bungle Range formation occupies an area of nearly 450 square kilometers. The Bungle Bungle Range is a spectacularly incised landscape was not really discovered as a travel destination until the mid-1800s. The researchers believed that the sedimentary rocks of Bungle Bungle were formed in the Ord Basin 350 million years ago, when active faults were altering the landscape. The stunning rocks rises up to 578 metres above sea level, and stand 200 to 300 metres above a woodland and grass-covered plain, with steep cliffs on the western face. If you’re flying over Bungle Bungle range, it is a striking sight. Moreover, the area was traditionally occupied by Karjaganujaru peoples; they’re living here for more than 20,000 years, having strong affiliation to this ancient landscape.

The joint effects of wind from the Tanami Desert and rainfall over millions of years shaped the domes. Although the formation appears solid, the sandstone is very brittle. The weight of overlying rock holds the sand grains in place, but when this is removed, the sandstones are without difficulty eroded. The rounded tops imitate this lack of internal strength. Moreover, the water flowing over the surface will exploit the softness and irregularities in the rock, such as cracks or joints, and swiftly erodes the narrow channels that separate the towers. Cyanobacteria can't grow here and without the protective coat the surface is exposed to "rusting". Thus, one of the most prominent features of the sandstones is the alternating black and orange or grey banding. However, the darker bands comprises of permeable layers of rock, which let water to move through with ease. As the water keeps the rock surface moist letting dark algae to grow on them. Hence, the less permeable layers in between are well covered with a patina of iron and manganese staining, producing the orange bands. These outer coatings support to keep the lower parts of the towers from erosion.

Furthermore, a 7 km diameter circular topographic feature is clearly visible on satellite images of the Bungle Bungle Range. It is supposed that this feature is the eroded leftover of a very early meteorite impact crater that maybe hit the area somewhere 250 million years ago. This beautiful structure is well known as the Piccaninny impact crater. The range remained largely unidentified except by local Aborigines and stockmen until 1982 when film-makers arrived in this area and produced a documentary about the Kimberley. The area was gazetted as a National Park in 1987 and was also inscribed as a World Heritage area in 2003.

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