Lake Mungo is a dry lake located in New South Wales, Australia. It is about 760 km (470 mi) due west of Sydney and 90 km (56 mi) north-east of Mildura. The lake is the central feature of Mungo National Park, and is one of seventeen lakes in the World Heritage listed Willandra Lakes Region. Many important archaeological findings have been made at the lake, most significantly the discovery of the remains of Mungo Man (the oldest human remains found in Australia), Mungo Woman (the oldest human remains in the world to be ritually cremated), and the location of the Lake Mungo geomagnetic excursion, the first convincing evidence that geomagnetic excursions are a geomagnetic phenomenon rather than sedimentological.
History Lake Mungo has been dry for approximately 20,000 years. The area that is now known as the Willandra Lakes Region was declared a National Park in 1979, and is the traditional land of the Paakantyi, Muthi Muthi, and Ngiyampaa people. These original inhabitants arrived approximately 50,000 years ago, and would have consumed emus and marsupials, as well as aquatic life such as crustaceans, freshwater mussels, and fish. In 1788, the First Fleet arrived in Sydney and spread several diseases to the Indigenous groups, such as Smallpox, subsequently resulting in depopulation for these communities. In the 1840s, European settlers physically invaded the land for agriculture purposes, bringing sheep and cattle for grazing. The indigenous groups who survived the seizure of their homeland and the European-introduced diseases, were forcibly moved to a mission at Balranald. In the 1920s, after WWI, settlers subdivided the Gol-Gol station for returned soldiers and created the Mungo woolshed, a station for shearing sheep. The station still exists today, and contains a 45-m woolshed built by Chinese laborers in 1869.
Land structures
Geology Sediments at Lake Mungo have been deposited over more than 120,000 years. On the eastern side of the Mungo lake bed are the "Walls of China," a series of crescent-shaped sand dunes or lunettes, up to 40 m (130 ft) in height, that stretch for more than 33 km, where most archaeological material has been found. There are five distinct layers of sands and soil forming the Walls. The oldest is the reddish Gol Gol layer, formed more than 120,000 years ago. Next is the greyish Mungo layer, split into Lower Mungo (between 55,000 and 40,000 years ago) and Upper Mungo (between 40,000 and 30,000 years ago). Above that is the Arumpo layer, deposited between 30,000 and 24,500 years ago, and finally the pale brown Zanci layer, laid down between 25,000 and 15,000 years ago. The Mungo layer, which was deposited before the last ice age period, is the most archaeologically rich. Although the layer corresponded with a time of low rainfall and cooler weather, more rainwater ran off the western side of the Great Dividing Range during that period, keeping the lake full. It supported a significant human population, as well as many varieties of Australian megafauna.
During the last ice age period, the water level in the lake dropped, and it became a salt lake. This made the soil alkaline, which helped to preserve the remains left behind in the Walls. Although the lake completely dried up several thousand years ago, ground vegetation remained on the Walls, which helped to stabilise them and protect them from erosion. With the arrival of European settlers in the area since the 1880s, introduced species, notably rabbits and sheep, have destroyed the vegetation cover. Herds of feral goats are also present in the region. This has led to increased erosion of the dunes. However, this erosion has led to the uncovering of many human and animal remains. Wind has moved sand and soil eastwards from the Walls, forming a mobile sand dune which moves farther east every year.
Formation of the 'mega-lake' Lake Mungo is one of 19 lakes that make up the Willandra Lake Region. The formation of these lakes occurred over the last two million years. Within the last 50,000 years, high wind levels created crescent-shaped dunes along the shores of these lakes, called 'lunettes.' Lake Mungo's water level was originally dependent on seasonal rainfall, runoff from the highlands of southeastern Australia, and overflow from nearby lakes and creeks. Between 22,700 and 24,700 years ago, an increase of runoff from the highlands and a shift in the basin of the lake due to neotectonic activity resulted in a "mega-lake" event. During this event, water levels rose 5 m and the lake volume increased by almost 250%. This overflow briefly connected Lake Mungo with the nearby Lake Leaghur, and the north part of the lunette temporarily formed an island. The creation of the lunette island temporarily restricted human mobility in this area. However, archeological discoveries indicate that humans were able to frequently visit the island to transport stone tools and food across the water by swimming or using watercraft. The "mega-lake" event was discovered using dGPS to measure main shoreline levels and comparing the results with a line of beach gravel that was more elevated than the main shoreline. It was determined that the event occurred during the transition into the Last Glacial Maximum (LGM) phase, which dates to approximately 26,000-20,000 years ago. Geological evidence indicates that due to the cold and dry conditions of the LGM, this caused the Willandra Lakes to subsequently enter a cycle of drying out and refilling. As a result, the "mega-lake" was a temporary occurrence that ended when the arid and cold conditions dried out the lake. Around 14,000 years ago, the Willandra Creek, an inflow channel for the Willandra Lakes, ceased to flow and resulted in the lakes permanently drying out. Since then, Lake Mungo has remained dry, however people continued to occupy this area.
Archaeological findings
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