Australia: The Land Where Time Began
Stirling Range Koi Kyeunu-ruff,
Less than 30 km to the north of the Porongorup Range lie the Stirling Ranges which were formed as Australia broke away from Antarctica. When the 2 continents began to separate a rift gradually opened. In the first stage of rifting, it began to open in the west, then in the second stage of rifting, 132-96 Ma, the eastern section began to open. It is thought that the 2 continents pivoted slightly at a point in the west, which squeezed the sediments at the western end of the break against the massive, and very solid, Yilgarn block, which forced the sediments up into a mountain range. The sedimentary rocks that were folded up to form the range have been dated to 1.2 billion years.
The highest part of southwestern Western Australia, about 80 km from Albany, there are no foothills, and with a few peaks rising to above 1000 m, they rise starkly above the surrounding plains. The range is about 70 km long and 15 km wide, running east-west, separating the dry Wheatland to the north from the southern fertile agricultural land. Most of the high ground in the area are composed of granite, but the Stirlings are composed of sedimentary rocks such as sandstone, quartzite, slate and shale.
The sediments that became the rocks of the Stirling Range were deposited in a shallow sea at the time of a marine incursion over a granite depression about 1.1 billion years ago. Following the retreat of the sea the area was subjected to a period of extensive faulting, the area of the future range subsiding. The surrounding area was eroded down to the granite and the range was gradually raised to a higher elevation than today's range, weathering and erosion having removed much of the original range. Parallel east-west faults can now be seen to be the northern and southern boundaries of the range. It is believed that the range was originally much higher than it is today. The large amount of erosion that removed much of the former range have carved the present range into various spectacular formations, especially on the craggy higher peaks. Sand ripples from the beds of ancient rivers can be seen in Chester Pass and Red Gum Pass.
The range is 1 of 2 distinct parts, north and south of the main path through the range, Chester pass. To the east, the range is mainly in the form of a a ridge from Mt Success to Ellen Peak, and including the highest point of the range, the 1073 m Bluff Knoll. To the west of Chester Pass the range is mostly formed of individual mountains, of which Mt Toolbrunup is the highest at 1052 m.
Because the climate of the Stirlings differs from that of the surrounding flat areas a number of unique wildflowers have evolved here. This range is considered to be one of the world's most outstanding botanical reserves, having nearly 1000 species of native wildflowers, more than 100 of which are unique to the Stirlings, some of which grow only on specific peaks of the range. As with other Australian ranges, the present range is much lower than the original range, having been greatly worn down by erosion. A number of rock formations, especially on the higher peaks, such as vertical walls, overhanging rocks and some tile-like patterns, make for interesting scenery. High up on the slopes of Red Gum Pass and Chester Pass there are sections of ancient seabeds where the ripples have been preserved. Ancient rivers carved courses through the range, such as the 2 passes mentioned above.
A paper by Birger Rasmussen of the University of Western Australia and colleagues published in a recent issue of Science provides dates and a detailed description of samples collected 10 years ago in sandstone of the Stirling Range Formation. The well-preserved fine ridges left in the sandstone have been interpreted as being slime tracks of a mucus-producing worm-like creature creeping over the surface of the sand. If they are correct, it will mean that these creatures lived twice as long ago as the previous record-holder for animals that lived permanently on land, as the tracks have been dated to in excess of 1.2 billion years old. It is believed the sedimentary rocks that were uplifted to form the range are of Ediacaran age, Ediacaran-type fossils have been found in the sediments.
The Qaaniyan and Koreng Aboriginal people originally lived around the range. In cold weather they wore kangaroo skin cloaks reaching nearly to the knee. They also established small, conical huts in wet weather. Sticks were placed in the ground and bent to form a cone, then threaded with paperbark, rushes or leafy branches. They told many stories about the Stirling Range, and in many of them the range is hostile and dangerous.
Bluff Knoll was called Pualaar Miial (great many faced hill) by the local Aboriginal people. This was because the rocks on the bluff were shaped like faces. The peak is often covered with mists that curl around the mountain tops and float into the gullies. These constantly changing mists were believed to be the only visible form of a spirit called Noatch (meaning dead body or corpse), who had an evil reputation.
The range was first recorded by Matthew Flinders in 1802. In 1831, Surgeon Alexander Collie recorded the Aboriginal name of the range, Koi Kyeunu-ruff, which was provided to him by his Aboriginal guide Mokare. Surveyor-General John Septimus Roe travelled to Perth with Governor Sir James Stirling in 1835 and glimpsed "some remarkable and elevated peaks". Roe called them the Stirling Range. The area was declared a national park in 1913, at a time where the dominant culture was towards clearing the bush and converting it to farmland.
The number and beauty of the wildflowers is staggering. The park is one of the world's most important areas for flora, with 1,500 species (many of which grow nowhere else) packed within its boundaries. More species occur in the Stirling Range than in the entire British Isles and 87 plant species found in the Stirling Range occur nowhere else on earth. This tally includes the famous mountain bells of the genus Darwinia. Needless to say, spring wildflower viewing is incredible.
Because of their height, and proximity to the south coast, the climate on the peaks differs from that of the surrounding district. This is the main reason for the great variety of wildflowers. There are, for instance, an astonishing 123 orchid species -- 38 per cent of all known Western Australian orchids. Between August to December the white flowers of southern cross (Xanthosia rotundifolia), which resembles the four stars of the Southern Cross constellation, are a common sight.
Thicket grows on the upper levels of all the major peaks. In spring, the thicket is a mass of flowering shrubs. The brilliant pink of Stirling Range pixie mop (Isopogon latifolius) contrasts strongly with the reds of the Nemcia species, the yellow of Dryandra and the white of the giant candles (Andersonia axilliflora). This mass flowering arrives later than that on the lowlands, and can be seen to best advantage in October, especially on a misty day when the clouds around the mountains enclose the visitor into this world of colour without the vista of the surrounding farmland.
Climate, clouds and snow
The climate of the Stirlings differs from that of the surrounding area, the abruptness of the rise from the plains has resulted in a cooler, moister climate than that of the surrounding country. The cold ,wet winters are a time of regular mist, rain, hail and even the occasional snow. The weather can be extreme at any time of year, and in summer there is usually not much permanent water in the ranges in the hot summer months when the creeks tend to dry up.
An ideal time to visit is late spring and early summer (October to December), when days are beginning to warm up and the wildflowers are at their best. Winter, between June and August, is cold and wet, and visitors should come prepared. Even in spring the weather can be unpredictable, particularly higher in the range. Sudden cold changes cause the temperature to drop and rain or hail to set in. All visitors are strongly advised not to enter the bush or use footpaths on days of extreme fire danger.
The Stirling Range is renowned for its unusual, and sometimes spectacular cloud formations. Park visitors may notice two types of unusual cloud formations about the peaks, often when the rest of the sky is clear. A shallow, low-level stratified cloud that drapes over the higher peaks is a familiar sight. Another type of shallow cloud layer may leave the higher peaks exposed, which is a unique sight in Western Australia.
The range is one of few places in Western Australia where snow occasionally falls. Snow probably falls on the highest peaks several times each year. On most occasions it is only a light dusting or the snow melts on impact. However, falls above five centimetres have been reported on Bluff Knoll. Snow may occur at any time in winter and sometimes in spring.
Stirling Range National Park
Koi Kyeunu-ruff - place of ever-moving about mist and fog. The aboriginal name is appropriate because of the unusual cloud formations that form around the highest peaks. These can occur even when the rest of the sky is cloudless.
The brooding beauty of the mountain landscape, its stunning and unique wildflowers and the challenge of climbing Bluff Knoll have long drawn bushwalkers and climbers to the Stirling Range National Park. At 1,095 metres above sea level, Bluff Knoll is the highest peak in the south-west of Western Australia. The main face of the bluff forms one of the most impressive cliffs in the Australian mainland. It takes three to four hours to complete the six-kilometre return climb.
The jagged peaks of the Stirling Range stretch for 65 kilometres from east to west. The rocks of the range were once sands and silts deposited in the delta of a river flowing into a shallow sea. Deposited over many millions of years, these layers of sediment became so thick and heavy that, in combination with unimaginable forces stretching the Earth's crust in the area, they caused the crust in the area to sink. As the surface subsided, still more sediment was deposited in the depression which was left. The final thickness of sediment is believed to be over 1.6 kilometres! As the sediment built up, so did the pressure on the layers below. The water was forced out of these layers, which solidified to become rocks known as sandstones and shales.
Buried deep in the Earth's crust, the rocks which form today's Stirling Range were gradually exposed over millions of years as the surrounding rocks were worn away by the forces of weathering (chemical breakdown) and erosion (physical removal of material by water, wind and gravity). It was during this process that the current form of the range was sculpted.
The highest peak in the range is Bluff Knoll, 1073 m. Though not high, by Australian standards they appear much higher because of the way they rise abruptly from the flat surrounding plains.
Flora and Fauna
Stirling Range is a biodiversity hotspot. In spring and early summer there is a burst of colour as many of the 1500+ species of plants flower. 123 species of orchid have been found in the Stirling Range National Park, 38 % of the total number of of orchids in western Australia. There are more than 140 bird species, the commonly seen being parrots and currawongs. The approximately 20 species of native animal are mostly nocturnal, so the most likely to be seen are western grey kangaroos, that mostly feed at dawn and dusk. The are more than 30 species of reptile, some of the snakes being venomous.
THINGS YOU NEED TO KNOW
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