Australia: The Land Where Time Began
Aboriginal Occupation - Tasmania (Flood, 2004)
The Tasmanian Aborigines are the only surviving human population who are known to have been isolated so completely by a natural barrier from the rest of the world for about 10,500 years. Once the land bridge joining Tasmania to the mainland had been flooded by the rising sea the difficult nature of the 250 km wide Bass Strait, with frequent storms and strong currents, as well as many submerged rocks that made any sea crossing in primitive craft such as canoes, sea-going or not, extremely dangerous and not likely to be attempted without good reason.
It is still recognised as a rough passage, it is the connection between the Indian and Pacific Oceans, with contributions from the Southern Ocean, the conditions made worse by its depth, only about 50 m. The huge volumes of water pushing through such a shallow section make for strong currents and rough seas. All this is made even worse by powerful winds. In the days of sail many ships were lost in it, often with no trace being found. It has been said to be twice as wide and twice as rough as the English Channel.
As a result of this isolation new technology or ideas couldn't be brought from the mainland, and as the dingo arrived and spread across the mainland after the drowning of the land bridge, it never reached Tasmania.
It has been estimated on ethnographic data that the population of Tasmania was about 3,000 - 5,000 at the time of the first European contact. This has been disputed on biological grounds, suggesting that such a small population inhabiting an island about 67,870 km2, about the size of Ireland would have undergone genetic drift over a period of 10,000 years resulting in biological divergence. An alternative suggestion is that the initial population at the time Tasmania was first occupied, about 35,000 years ago, had risen to a much higher level by natural increase by the time of isolation, declining subsequently to the comparatively low level at the time of European contact.
Excavation of a number of occupation sites has shown that the tool kit at the time of separation from the mainland was very similar to that on the mainland.
Tasmania is the most southerly part of the world inhabited during the Ice Age. Glaciers were present on Tasmania's mountains and icebergs would have drifted past its coasts from the Antarctic, 1000 km further south. When sea level dropped as a result of glaciations, a broad land bridge was exposed from early in the Ice Age. It is thought the land connection would have been available from about 60,000 BP, early in the Ice age, so was present when the first Aborigines arrived in northern Australia. It lasted until about 10,500 BP.
So far the earliest occupation site in Tasmania dates to a bit more than 35,000 BP. At least 4 other sites, Nunamira, ORS 7, Palewardia Walana Lanala, and Bone Cave, all have dates of 30,000 BP or more. No doubt there would have been occupation sites on the now-submerged land bridge that could be even older.
A feature of the Tasmanian cave occupation sites is that at the start of occupation there is light, intermittent use of the caves, especially during the period of the glacial maximum. Another constant feature of these sites throughout the Pleistocene is the constant exploitation of the red-necked wallaby and marrow extraction. They appear to have been red-necked wallaby specialists.
It has now been shown that by 35,000 BP Aborigines had developed a way of life that allowed them to live in the alpine environment of upland Tasmania. At the glacial maximum, about 18,000 BP, annual average temperatures were about 6o C lower then present, and glaciers in Tasmania extended to 800 m above sea level. The treeline was at least 235 m lower. The glacial Tasmanian climate has been equated with that of the Australian Alps at Mt Hotham, at 1862 m, of the present, but with shorter summers.
In the times prior to, and at the height of, the last glaciation the climate here was periglacial, sub Antarctic, but the river valleys were free of big trees which made movement through them much easier than when the rainforest became established by the end of the Pleistocene. It had previously been suggested that the intermittent nature of occupation in the highland caves of Tasmania was because they were used during summer hunting expeditions. If they were actually winter campsites, the occupants would be able to escape the worst of the freezing conditions prevailing in the area in winter, and could explain why the vast majority of prey seemed to come from a single species, the red-necked rock wallaby, which would have been easily available to the hunters.
In some cave deposits emu eggshells have been found. These are available only in spring and early summer, so they could have varied their diet with the eggs while the weather was still cold, before the conditions warmed up enough to move out for the summer. It is possible they might have remained in the caves all year, but that would require them to be comparatively sedentary and mean they hunted only rock wallabies all the year.
The inhabitants of southwest Tasmania had a more highly structured economy than any other part of Australia during the Ice Age. The Pleistocene Tasmanian industry differs from that of other Australian sites of this time. Darwin glass was transported over 100 km, indicating a probable trading network. There were also differences between the east and west of Tasmania during Pleistocene times, showing the adaptability of these people to changing environments. Changes in technology and economy also occurred over time. In the lowest layers there is neither Darwin glass nor thumbnail scrapers, and there is possibly an increase in mobility, and land use patterns changed during and after the glacial maximum.
The finds from Pleistocene sites in marginal climatic regions in Tasmania show a highly complex society. Pigmented art shows the possibility of religious activity in the deep caves of Tasmania. There are further indications of complex societies, with their own distinctive archaeological signatures prior to the mid-Holocene when changes were thought to have occurred.
During the Pleistocene there was a wide variability between the assemblages in the southwest and the southeast of Tasmania. There were also cultural differences between the 2 areas. In the west, temperate rainforest covered the fold structure of the southwest, with its impenetrable horizontal forest. In the east there were dry sclerophyll forests on the fault-structured geology. This pattern differs from the concept of an Australia-wide Pleistocene culture and technology that was uniform, simple and unchanging.
By the end of the glaciation the link with the mainland had been cut by rising sea levels. The inhabitants of southwest Tasmania thrived though 20,000 years, the last 10,500 years in isolation.
The southwest of Tasmania has one of the last remaining temperate wildernesses in the world and in it is some of the densest rainforest in the world. At the time of European contact the population of Tasmania was largely restricted to a narrow coastal belt only a few hundred metres wide that they kept open with fire. Their main food source was from the sea. They tended to travel along the coast rather than inland, and only a couple of tracks through the rainforest are known, as from Port Davey to the south coast. Little, if any, occupation is known of in the wilderness of the southwest. The horizontal scrub and the fast-flowing rivers would have been a significant disincentive to try to penetrate inland, especially as they lived so well on the coast. The rivers are still a problem for anyone wanting to travel upstream in a boat; jet boats are required to overcome the powerful flow.
The first evidence of Aborigines in the rainforest was found by accident, stone tools being found on the bank of the Gordon River around the base of a fallen Nothofagus. The tree roots had exposed the stone tools as they pulled out of the ground. There was a quartz pebble core with the flakes that had been chipped from it scattered around it. The flakes fitted exactly with the scars on the core, and they were still extremely sharp. 12 tools were found, including a quartz hammerstone. Associated charcoal at this site gave a disappointingly recent date of 300 +/- 150 years. The Aborigines had at least traversed the area in recent times.
The next find, only 3 weeks later, was at Kutikina Cave.
|Author: M.H.Monroe Email: email@example.com Sources & Further reading|