Australia: The Land Where Time Began

A biography of the Australian continent 

The Landing Site of the First Settlers in Australian

At the time the first settlers arrived at the Australian coast it was on the exposed continental shelf, as the sea was about 70 m lower than the present level, that continued from the western Kimberley to the Torres Strait and then another 2,000 km from the Gulf of Papua to north Fraser Island. The continental shelf covered a total area of 1.6 million km2 before it was flooded about 10,000 BP. The coastline along which the settlers advanced would have advanced along was probably a diverse subtropical plain covered with pristine rainforest, grassland, woodland and savannah.

Between 70,000 and 60,000 BP global temperature was decreasing and the the sea levels were dropping and the land was continuing to dry, then after about 60,000 BP the world began to warm and the sea level began rising. Over the next 10,000 years there were 2 cycles of global warming and cooling, the overall trend being to cool and increasing aridity. In spite of the cyclic ameliorations to this more general trend the climate was getting colder and drier. The climate was cool and dry again by 50,000 BP, and the sea levels were 70-80 m lower than at the present. Over the next 10,000 years the climate continued to oscillate, going through 2 more cycles of warming and cooling, then after 45,000-40,000 BP the conditions were more arid. There were 2 environmental stages over this period of time, the first from 70,000-60,000 BP, when the conditions began the slide toward glacial conditions, with sea levels about 70 m below the present sea level. The second was from 60,000 BP to about 18,000 BP, when the world, including Greater Australia, endured long periods of increasing aridity and increasing cold. The overall pattern was gradual cooling and drying. Almost 120,000 BP was the last time the Australian climate and environment looked and felt as it does at the present.

Wherever the first arrivals landed it is likely they settled near water on a reasonably soft shoreline. The Cane1 suggests it is reasonable for them to have been on a peninsula similar to the Coberg Peninsula of the present, though they could have landed anywhere along the coastal plain that is now submerged, possibly near a river mouth, blown up against a precarious rocky promontory, in a mangrove forest or on a broad, long open beach. Wherever they landed the coastal hinterland would have been not much different from what it is at the present, wide valleys that were sloping towards the sea, subdued plains and broad river systems. It would have been an environment that would allow them to survive long enough to become established.

They could possibly have landed in the far north, within the west-facing arm of the cordillera in New Guinea. They could have moved inland, along rivers and into the mountains, though the author1 believes it is more likely it would have been a coastal route where they would be directed by the topography towards a broad land bridge that joined Cape York and Papua New Guinea. The sea is 12 m deep in Torres Strait, at the time when it was Torres Plain it would have been 40-50 m above sea level. Some channels cut through the land to depths of up to 120 m, which would have provided estuaries and sea channels where hunters and gatherers would have been able to find plenty of food. If they crossed to the south over the Torres Plain they could have arrived at a huge embayment that surrounds what is now the Coral Sea. At that time they could have walked to the margin of what is now the Great Barrier Reef, and foraged in the lace-like network of ridges and canyons that now anchors the reef.

An alternative could have been the western route to the Australian mainland via the open plains and many river systems into the lakes and lands of Carpentaria. The Gulf of Carpentaria was dry land with a vast lake in the middle between 70,000 and 50,000 years ago. Lake Carpentaria, the central lake, was fed by 37 ancestral rivers carrying a total of 12,700 gigalitres of fresh water into the lake system per year. For comparison Sydney Harbour holds 560 gigalitres. The lake was one of the largest ever lakes in the world, at 500 km long and 250 km wide, though it was shallow, being 15 m deep on its eastern side. The nature of the lake fluctuated along with the sea levels. The environment changes from a lake to an embayment as the sea level rose, as there was a channel connecting the lake to the Arafura Sea when the sea level was high enough. When the sea level was 75 m lower than that of the present it was a lake, though once the sea level had risen 15 m, to about 60 m below the level of the present, it became a brackish swamp. It became an embayment surrounded by many lakes when the sea rose another 15 m.

The Cane1 suggests the lake must have been a perfect Eden-like environment, though an Eden with giant crocodiles, snakes and goannas. From the sea in the greater region any experienced sailors would have recognised the signs of a body of fresh water, by the travel directions of sea birds and migratory birds, and in the sea, the presence of flood-washed vegetation, driftwood, and discolouration of the sea as a result of freshwater discharge.

Settlement at this location would have been close to ideal, with plenty of fresh water, many rivers, tributaries and small lakes which they could live around, as well as hunt, gather shellfish, fish, dugongs and turtles, birds and terrestrial game. Pollen analysis of sediments deposited over the last 40,000 years has revealed the presence of black soil plains that were vegetated by eucalyptus, bottlebrush and Callitris pines, and growing in the waterholes and lakes, water lilies, yams and bulrushes, which all sounds very similar to Kakadu of the present. The extensive systems that drain towards Lake Eyre Basin would have provided a corridor for the settlers to travel south. The continent was open to them, though the deserts were also in front of them, the author1 suggesting expansion may have been sporadic, as allowed by the cyclical climatic ameliorations of regional weather patterns.

The Arnhem Land coast, with magnificent escarpments, is located to the west of the Lake Carpentaria. At that time the Alligator River, Wildman River, Mary River and Adelaide River all eventually fused into a single river, to form the Arnhem Land River that was deeply incised. Between Coberg Range, that is now the Coberg Peninsula, and Melville Hill, that is now Melville Island, this river flowed through a gentle valley onto the extensive Arafura Plain, that is now the Arafura Sea, eventually joining the giant Arafura River, flowing south from Papua New Guinea and on to the Indian Ocean. The Arnhem Land Plateau, 200 km wide and 250 m above the alluvial plains was, and remains, a living environment that is remarkable, with small rivers incised, overhung with waterfalls, and skirted by fertile wetlands and savannahs. The total environment had abundant food, water and shelter.

If the settlers had landed at, or traveled west along the great northern coast, they would have arrived at the Ashmore Peninsula, now Ashmore Reef, beside a huge basin central to the Joseph Bonaparte Gulf of the present. There was a large lake in this basin with an area of 20,000 km2 and with a large freshwater catchment that was 350,000 km2, Lake Argyle, for comparison, is 1,000 km2. A valley that was relatively deep-sided, connected the lake to the ocean, the sub-oceanic Malita Valley.  Tidal movements in this area are massive and dangerous at the present, as they may have been in the past. If this was the case in the past the out-pouring of water through the Malita Valley must have been spectacular.

The Cane1 suggests it is likely the lake and associated embayments would have been rich living environments, with both marine resources near the coast and freshwater resources further inland, where monsoonal rains penetrated the great basin by great rivers. Something of the magnitude of these rivers in past times can be seen in the rivers of the present, though they are now smaller. Some of these rivers are the Mitchell River, 117 km long with a catchment of 2,970 km2, the Drysdale River, 423 km long and a catchment of 8,400 km2 and the King Edward River, 221 km long and a catchment area of 15,690 km2. These were long and fertile avenues that could have been settled and from which they could expand their territory and lead the settlers to the rugged plateaus of the Kimberley, and from there other large freshwater rivers ran to the west and south, eventually reaching the sea, as well as leading people to the desert. An example is the Fitzroy which skirts the Kimberley for 640 km, which has an extensive catchment of 83,000 km2. Following this river eventually leads to the Sturt Creek and dendritic channels of Tjurabalan (Milkwater), and to Paraku (Lake Gregory), a large seasonal lake that borders the Great Sandy Desert.

Sources & Further reading

  1. Cane, Scott, 2013, First Footprints: The epic story of the first Australians, Allen & Unwin 

Scott Cane has included in his book, written as a companion to the ABC TV series of the same name, a number of stories from his days living among Aboriginal people in the desert and moving around with them.

Author: M. H. Monroe
Email:  admin@austhrutime.com
Last Updated 13/11/2013
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                                                                                           Author: M.H.Monroe  Email: admin@austhrutime.com     Sources & Further reading