Mungo is a very special place where geology and archaeology have been brought together. In 1969 Geomorphologist Jim Bowler discovered a the remains of a human skeleton (later named Mungo Lady) in this area. Although he was not an Anthropologist, his expertise in the field of stratigraphy helped him to understand that this was a very important discovery, as these bones were found in the stratum which he understood to be over 36000 years old.
The Mungo landscape consists of :-
Playas and Basins
Mungo is an ancient dry lakebed. During the last ice age, Lake Mungo was one of a chain of freshwater lakes strung along the Willandra Creek.
The lakebed soils are a mosaic of grey and red heavy clays and in places contain channels and gilgais (small, temporarily existing lakes formed from a depression in the soil surface in expanding clay soils.) The claypan where a number of ancient footprints were discovered ( and still lie) is about 15 cm thick and made up of thin layers of a type of magnesite rich clay. The clay was probably blown out of the nearby lake basin in dry periods, by dune sands blowing in from the west in the barren, windy climate of the Pleistocene (the geological period which lasted from about 2,588,000 to 11,700 years ago.)
Sandplains
The undulating sandplains consist of calcareous loamy to sandy loam red and brown soils with isolated depressions of grey clays.
Dunefields
The dunefields of the park include: parallel dunes of deep loamy sand with narrow depressions of chalky loamy red earths; horseshoe shaped dunefields and unaligned dunes with deep sandy red soil hollows; high unstable dunes of deep white sand interspersed with flats of loamy brown soils containing calcium carbonate. You can experience walking on some of these dunes if you take the 70km drive around the National Park.
Lunettes
The lunettes are major landforms of great importance to the ancient heritage of the area. Four major layers of sediment form the Mungo lunette, and each represents a different period of time and different environmental condition. Three of the layers have been given local names. One of your tasks in this Earthcache will be to gather more information about these layers. The bottom layer of the lunette is made up of deep red calcareous soil. The next layer is made up of quartz sands that were blown from wave-nourished beaches, indicating the lake was full. This is the layer which contains burials over 36,000 years old.
The layer on top contains the final stage of clay lunette formation. The water flow decreased which lowered the lake water levels and exposed mud and clays on the lake floor. Salts that had accumulated in the exposed mud crystallised and they broke into sand-grain sized pellets. These were carried by the prevailing south-westerly winds onto the lunettes to form a series of clay blankets. This accumulated up until 15,000 years ago.
Over thousands of years, wind and water have carved the lunette into the spectacular formations we see today. Rain washes away the soft sands and mud, creating the frilled ridges and residuals that characterise the Walls of China. The dislodged sand is then picked up by the wind and heaped into huge mobile dunes along the back of the lunette. The constant erosion also reveals more and more evidence of ancient civilisation.
There is an excellent Visitor Centre at Mungo National Park. Allow yourself plenty of time to absorb all the information there and have a look at the outside area. There is a vehicle entrance fee to the Park, and a cost to take a guided tour amongst The Walls of China. This tour is not necessary to complete your Earthcache tasks. There is a 70km round trip driving tour (thoroughly recommended)which will give you a better appreciation of the landscape.
Click here for information on this Park.
EARTHCACHE TASKS
Go to the listed co-ordinates and answer the following questions:-
1. Name the 3 named major layers of sediment in the Lunette.
2. What do these names represent?
3. How old is the oldest layer?
Then proceed to S 33 44.559 E 143 07.619 and describe what you can see here
Photographs of your visit would be appreciated.