How old is the continent of australia

For much of its history Australia was joined to New Guinea, forming a landmass called Sahul. These countries were finally separated by rising sea levels about 8, years ago. Genetic evidence supports the close ties between these two countries — the Indigenous peoples from these regions are more closely related to each other than to anyone else in the world, suggesting a recent common ancestry.

There are a number of likely paths of migration across Asia and into Sahul. These are based on the shortest possible route and take into consideration the land bridges that would appear during times of low sea levels. However, travel may have also occurred when sea levels were high. High sea levels would have reduced the amount of usable land and increased the population pressure.

During these times it may have been necessary to expand into new areas. Changing sea levels have significantly affected the geography of South-east Asia and Australia and the migration patterns of prehistoric peoples.

During times of low sea levels the travelling distance between Timor and Sahul would have been reduced to about 90 kilometres. Present sea levels are higher than they have been for most of the last million years. When water is locked up in the polar ice caps known as an Ice Age the sea level drops.

When the climate becomes warmer, the ice melts and the sea level rises again. The settlement of Australia is the first unequivocal evidence of a major sea crossing and rates as one of the greatest achievements of early humans.

However the motive and circumstances regarding the arrival of the first Australians is a matter for conjecture. It may have been a deliberate attempt to colonise new territory or an accident after being caught in monsoon winds. The lack of preservation of any ancient boat means archaeologists will probably never know what kind of craft was used for the journey. None of the boats used by Aboriginal people in ancient times are suitable for major voyages. The most likely suggestion has been rafts made of bamboo, a material common in Asia.

The earliest accepted dates for human occupation of Australia come from sites in the Northern Territory. Over the last few decades, a significant number of archaeological sites dated at more than 30, years old have been discovered.

By this time all of Australia, including the arid centre and Tasmania, was occupied. The drowning of many coastal sites by rising sea levels has destroyed what would have been the earliest occupation sites. Recently published dates of , years ago for the site of Moyjil in Warrnambool, Victoria, offer intriguing possibilities of much earlier occupation Proceedings of the Royal Society of Victoria , Much of our knowledge about the earliest people in Australia comes from archaeology.

The physical remains of human activity that have survived in the archaeological record are largely stone tools, rock art and ochre, shell middens and charcoal deposits and human skeletal remains. These all provide information on the tremendous length and complexity of Australian Aboriginal culture.

The oldest human fossil remains found in Australia date to around 40, years ago — 20, years after the earliest archaeological evidence of human occupation.

Nothing is known about the physical appearance of the first humans that entered the continent over 60, years ago. What is clear is that Aboriginal people living in Australia between 40, and 10, years ago had much larger bodies and more robust skeletons than they do today and showed a wide range of physical variation.

Stone tools in Australia, as in other parts of the world, changed and developed through time. Some early types, such as wasted blades, core tools, large flake scrapers and split pebble choppers continue to be made and used right up to today.

About years ago, new and specialised tools such as points, backed blades and thumbnail scrapers became common. Significant variation between the tool kits of different regions also appeared. Prototypes for this technology appeared earlier in Asia, suggesting this innovation was introduced into Australia. The ground stone technique produces tools with a more durable and even edge, although not as sharp as a chipped tool. Northern continents formed the great landmass Laurasia.

These two supercontinents shared many plants and animals dating from an earlier time when they were joined as one enormous landmass.

The Australian Museum respects and acknowledges the Gadigal people as the First Peoples and Traditional Custodians of the land and waterways on which the Museum stands. Image credit: gadigal yilimung shield made by Uncle Charles Chicka Madden. This website uses cookies to ensure you get the best experience on our website. Learn more. Toggle Caption A typical landscape of the late Cretaceous Period, c75 million years ago.

Australia's Cretaceous facts. At the time, each was still linked to rocks that are now found elsewhere in the world. Surprisingly, the cratons that came from the three continents are broadly defined by our present state and territory boundaries. As the ancestral plates moved around, these three continents smashed into each other and formed ancient mountain belts. These mountains are now eroded to low stumps — such as the Musgrave Ranges in central Australia — or buried beneath much later sediments, such as those that make up the vast western deserts.

The boundary between the West Australian Craton and the other cratons lies buried beneath the Nullabor Plain in the south, and beneath the Great Sandy Desert further north. Until very recently, geologists thought this collision, which brought together much of the continent, occurred million years ago. This was based on the ages of some rocks poking out of the Great Sandy Desert in remote Western Australia.

But intriguing recent research using new dating techniques suggests that the collision represented by these rocks is actually million years younger than anyone thought. New exploratory drilling by state and federal geological surveys also suggests that an ocean once separated Western Australia and South Australia until at least 1, million years ago.

This ocean was named after the Mirning people who are indigenous to the region. Closing the Mirning ocean bought Australia together for the first time, around 1, million years ago.

Towards the east, the flat land rises to the Great Divide which runs parallel to the east coast from the tip of the Cape York Peninsula in Queensland almost km south to the Grampians in Victoria. This separates rivers flowing to the west and north from those flowing to the Pacific. The Eastern Highlands are made up of a series of mountains in the south topped by Mount Kosciuszko and volcanic plugs, ash domes and flow remnants further north. These formations were created as Australia moved over a volcanic hotspot.

Some southern plateaus are dissected by erosion into rugged hills with the eastern edge forming the high escarpments. Some of Australia's most spectacular waterfalls occur where rivers flow over the Great Escarpment. The past few million years were notable for the Quaternary ice age which resulted in various glacial and interglacial periods.

The last glacial period was at its most intense about 20 years ago, and by around 11 years ago the ice had retreated and rising sea levels separated mainland Australia from Tasmania and New Guinea.

In Tasmania there is evidence of three different glaciations but on mainland Australia, there is evidence of only the last glaciation. During this event ice covered about 25 square kilometres in the vicinity of Mt Kosciuszko , with the most significant remnant being the Blue Lake cirque.