|Mungo National Park|
Mungo National Park is 110 km north-east of Mildura in south-western New South Wales in the Willandra Lakes Region.. This is a semi-arid part of Australia with average annual rainfall of about 250mm and daytime temperature exceeding 35°C at times. A major feature of the park is the dry bed of Lake Mungo.
The region is a vast riverine plain made up of the flood-plains and deltas of the Murray, Murrumbidgee and Lachlan Rivers. The area is nearly flat so waterways have little abrasive power and streams tend to be sluggish, meandering and frequently moving their beds. During millions of years, repeated periods of erosion and sedimentation have formed and re-formed rivers and streams. About 400,000 years ago, Willandra Creek, then a northern channel of the Lachlan River, was cut off by wind-blown sand moving from the south-west and Willandra Lakes were formed. Lake Mungo was one of these lakes filled by rainfall and river inflow. In succeeding centuries, the prevailing westerly wind whipped up waves which shaped the lakes' rounded shoreline, especially on the eastern side, so that lakes in the Willandra system (and elsewhere in inland New South Wales) now mostly feature smoothly rounded eastern shorelines.
Climate change during this period, often associated with ice ages, bought long periods of cold, dry and windy weather leading to Lake Mungo drying up for many years before rain returned. When the lake bed was dry, prevailing winds picked up sand and dust from the lake floor and dumped it along the eastern shore forming a large crescent-shaped dune now called a "lunette" because of its resemblance on a map to the crescent-shaped moon. Even when the lake contained water, sand blown from the lake shore was added to the dunes and lunette formation continued.
Three main periods of lunette formation have been identified based on the colour of deposits and the material contained in them. Oldest is Gol Gol unit laid down more than 45,000 years age. The brownish-grey Mungo unit, laid down between 44,000 and 25,000 years ago, represents a period of variously high and low water level during which aboriginal people lived along the shores and the dunes were sometimes covered by vegetation. Considerable runoff from the western slopes of the Great Dividing Range kept the lakes full for much of this time. Lake Mungo supported a significant human population, as well as a range of megafauna.
This layer is the most archaeologically rich and contained two human skeletons. Mungo Man and Mungo Lady are estimated to be 40,000 years old; Mungo Man is believed to be the oldest human remains found in Australia. The Mungo layer contains stone tools, middens, hearths, human burials and a range of bones from animals, including now extinct megafauna species.
|An ice-age peaking between 20,000 and 18,000 years ago led to cold and dry conditions under which Lake Mungo became a salt lake with a receding shoreline exposing grey clay lake bed which dried and blew onto the lunettes forming the Zanci deposits of grey clay and sand. Alkalinity in the deposits on the dunes helped preserve remains in the lunette. The lake dried out temporarily 16,000 years ago and was permanently dried out by 10,000 years ago.|
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At its greatest extent, Lake Mungo was 10 metres deep and measured 10 by 20 kilometres.
After the water dried up , Saltbush and Bluebush communities colonised the lake bed covering the exposed clay and ending wind erosion. Other plant species covered the lunette dunes. Beyond the lunette and lake, different plant communities thrived. By the time of European settlement in the mid-nineteenth century there were six recognised plant communities in and around Lake Mungo: Mallee, Belah (a form of Casuarina), Grassland, Cypress Pine Woodland, Grassland, Mixed Shrubland, Bluebush/Saltbush Shrubland.
The 1850s and 1860s were a period of pastoral expansion in Western New South Wales, facilitated in part by availability of paddle-steamers on the Murray-Darling system able to carry wool to market. Land along the Murray and Darling Rivers was taken up first, while land further back from the rivers was not taken up until the 1860s. High wool prices were another important factor driving settlement. As part of this expansion, half a million acres (203,000 hectares) including Lake Mungo, was taken up in the 1860s to form Gol Gol station. Sheep ranged widely over the fragile vegetation destroying much of the ground cover stabilising the dunes. These original white settlers did not have a clear idea of the productivity of this land and usually stocked according to the total vegetation growing on the land, not on the amount added in each growing season.
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This pastoral practices led to overstocking and, eventually, to inevitable collapse of pastoral activity when there was insufficient feed for the sheep. Rabbits arrived at about the same time adding to the destruction.
Overstocking caused damage to ground cover on the lunette and exposed more of the sand and clay to erosion. Rain washed soft sand and muds from the lunette creating the vertical ridging so prominent today; wind picked up the dislodged sand and heaped it into a huge mobile dune immediately behind the lunette. The edge of this dune is advancing steadily away from the lunette as it expands by the addition of yet more material from the lunette. Roots of trees and shrubs on the lunette are being exposed and plants will be uprooted as erosion continues. The eroded faces are called the Walls of China supposedly in connection with the Chinese workers building the woolshed at Gol Gol in 1869.
Prosperity for Gol Gol station crashed in the terrible 1890s with the shearers' strike of 1890, the depression of 1891-92, bank crashes of 1893, and the drought of 1895-1903. The already overstocked, semi-arid land was completely unable to support sheep trying to graze over it and rabbits made the situation worse.
In 1922 Gol Gol station was subdivided into smaller holdings under the closer settlement scheme intended to allow returned soldiers to settle on the land. One such unit of the former Gol Gol became Mungo station of 16,000 hectares (40,000 acres). This smaller area could support only 3,500 to 4,000 sheep; there is some doubt whether that was enough of that semi-arid land to be commercially viable and the property changed hands in 1934. It was acquired by the New South National Parks and Wildlife Service in 1978 and listed as a national park in 1979. Removing sheep from the national park has reduced the impact on the land but rabbits remain and much damage has already been done.
|Sand blown from the Walls of China is being deposited immediately behind the Walls on the growing dune shown
in the upper picture. Removal of material from the Walls of China exposes roots of plants (lower picture) which will die as the process continues.
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In 1984 Mungo National Park incorporated Zanci station which had also been one of the smaller holdings, adjacent to Mungo, established in 1922 when Gol Gol was broken up.
# Mungo National Park incorporates a variety of feature and attractions. The best known is probably the dry lake bed with the Walls of China stretching for 33 kilometres along the eastern margin. The NPWS has built a Visitors Centre just inside the park entrance and a gravel road runs across the lake bed to the parking/viewing area facing the Walls of China.
# The National Park has retained many of the buildings and structures erected while the land was part of pastoral properties (Gol Gol, Mungo and Zanci). The most obvious is the Mungo Woolshed (shearing shed) adjacent to the Visitors Centre; this has been restored and visitors are invited to enter and wander around. The dugout used by residents at Zanci homestead to live partly underground to escape the heat has also been retained, although the homestead itself is gone. Several dams and tanks remain as well as the stables at Zanci.
|Dugout at Zanci homestead was built by the Vigar family as a retreat from the extreme heat of summer days. In
the half underground bunker the humidity remainer higher and the temperature lower than in the nearby homestead.|
|Zanci stables. A building with drop pine log-wall and spinifex thatch; a typical construction method of the time.|
# A 70-kilometre self-drive tour (best done in a 4WD vehicle) has been devised as a round trip around the Lake and the Walls of China. The tour includes Allens Plain on the other side of the lunette from the Visitors Centre and has been devised to touch on the different plant communities living around the lake as well as remnants of former pastoral activity. The vegetation of the park is typical of that of the plains of western NSW. A guide sheet describes points of interest around numbered markers.
# A side track from the self-drive tour goes to Vigars Well, this used to be a well for watering coaches and drays but is now at risk of being overwhelmed by the sand dune advancing from the Walls of China. This dune can be climbed from the Vigars Well car park.
# Although much has been made of the archaeological significance of Mungo Lakes this aspect is under-emphasised in the park. A Diprotodron reconstruction in the Visitors Centre represents the extinct megafauna, but, for aboriginal cultural reasons, there is no attempt to publicise human remains. Continuing erosion along the Walls of China is relied on to expose artifacts so there are no diggings to show tourists.
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¶ Mungo National Park by Alan Fox, published by NSW National Parks and Wildlife Service (Western Region), 3ed, 2002 reprint.
¶ Wikipedia at http://en.wikipedia.org./wiki/Lake_Mungo in November 2009.
¶ Discover Murray at http://www.murrayriver.com.au/river-towns/mungo-national-park/ in November 2009