Echidna Chasm EarthCache

Echidna Chasm is an outstanding example of a sandstone slot canyon. Slot canyons are found in many parts of the world, predominantly in areas with low rainfall. A slot canyon is a narrow canyon, formed by the wear of water rushing through rock. It is significantly deeper than it is wide. Only a very small number of creeks will form slot canyons due to a combination of the particular characteristics of the rock and regional rainfall. Some of the best-known slot canyons are to be found in the southwestern USA (Antelope Canyon in Arizona, Zion Narrows in Utah). Other significant areas include the Sierra de Guara in northern Spain and the Pyrenees on the border of France and Spain. Examples in Australia can be found in Wollemi National Park (NSW), Karijini National Park (WA) and Carnarvon Gorge (QLD). 

The chasm cuts deep into the front of  the Bungle Bungle range, a mass of conglomerate and sandstone, several hundred metres thick. The sedimentary rock was made from sand and gravel that was eroded from a massive mountain range, a process that started 360 million years ago in the Devonian Age. A large river system deposited here many layers of sand and sediment, which eventually turned to rock under the pressure of millions of tonnes of sediment. 

But how was the chasm formed? An aboriginal Creation Time story explains... In the time of their ancestors, the care-free lifestyle of the echidna spirit irritated the cockatoo spirit so the bird chased him through the bush alongside a tall cliff and plucked out some of his spines. The echidna pushed against a small crack in a cliff face and it enlarged to form a chasm in which he found refuge. The chasm walls swept his spines backwards and they have forever pointed in this direction. The plucked spines became the endemic miniature Livingstonia palms that are found along the chasm. 

Modern geology gives another explanation: A joint or fracture in the range was the initial weak point where the formation of the chasm started. Millions of years of erosion by water and wind deepened it. Further erosion has cut deeply into the range. Water flowing across rock surface still becomes channelled along smaller joints and into the chasm.