Australian thematic contexts, themes and sub-themes of outstanding universal value identified by the Panel are summarised below:
Thematic Context: `An Ancient Land'
The `Ancient Land' thematic context derives from the long-term geological stability of the Australian continent. Geological stability is a characteristic that has resulted in only relatively minor change to Australia's geological substrates and many of its landscapes over extremely long periods of time. Australia is unique in exhibiting this stability at a continental scale. In contrast, most other continents have been subject to large-scale geological processes that have resulted in extensive change, including the obliteration of records of early landscapes and biota.
Australia's unique geological stability is of prime importance in telling the story of the early development of life on the planet. The significance of this thematic context centres on the fact that outstanding examples of ancient landforms and fossil remains of early life forms are readily visible in parts of the Australian continent. These include fossil remnants of the earliest known forms of life on Earth, dating back more than 3.4 billion years.
The following theme and sub-theme of outstanding universal value associated with the `Ancient Land' thematic context was identified by the Panel:
Theme: Ancient records of life and landforms
Sub-theme: Ancient landforms and fossils
Explanation: Australia has outstanding examples of the earliest known records of life and early physiographic features.
Thematic Context: `Continental Isolation'
The `Continental Isolation' thematic context is associated with the origin and development of the Australian continent. In particular, it draws on Australia's origins as part of the supercontinent Gondwana, the unique, long-term isolation of the Australian land-mass following the break-up of the supercontinent, and the onset of increasingly stressful environmental conditions as the newly-isolated continent moved slowly northwards as a result of global plate tectonics. With this northwards movement came greater climatic unpredictability, as the continent came under the influence of different atmospheric systems.
As Australia separated from Gondwana, new continental boundaries developed. The boundary which formed along Australia's eastern edge is of the type known as a passive continental margin. This type contrasts with active continental margins that exhibit high seismic and volcanic activity. While passive continental margins are relatively common on a global scale, Australia's eastern boundary is unusual in that along much of its edge it coincides with sites of volcanic activity. The timing of volcanic activity at each of the sites can be determined because volcanic rocks, unlike many other types of rocks, can be directly dated. Because the sites happen to be associated with the continental margin, the history of the margin itself can be studied through the dating of the sites. This is unique on a global scale as passive continental margins, by definition, are not usually associated with volcanic activity.
The global significance of Australia's relative geological stability has been discussed for the `Ancient Land' thematic context. This stability is also important for the development of the Australian continent. For example, Australia has remains of ancient land surfaces termed `palaeoplains' which are outstanding on a global scale. These features are substantially expressed by the continent's very old soils such as laterites and duricrusts. Other significant features are the remains of ancient river systems, some of which pre-date the break-up of Gondwana.
The `Continental Isolation' thematic context is central to any understanding of the origins and development of Australia's past and present landscapes, flora and fauna. It centres on the co-evolution of landscapes, biota and, latterly, human societies under high levels of environmental stress associated with various combinations of increasing climatic variability, low nutrient soils, high fire frequencies, and the interaction of surface water and ground water in a flat landscape.
The vegetation has adapted to these stresses in a variety of ways, many of which are exceptional on a global scale. For example, the development of scleromorphy (typically hard, thickened leaves and pronounced leaf cuticle development) in response to factors such as water stress and low nutrient soils is unmatched in any other continental floras. Similarly outstanding is the adaptation of eucalypts, which dominate forest and woodland vegetation on a continental scale, to an extraordinary range of environments and conditions.
The low nutrient soils are particularly unusual on a global scale. The majority of Australia's soils are derived from ancient, heavily leached substrates, formed when the climate across the whole continent was warmer and wetter. Also associated with the pronounced age of the continent is its relatively flat landscape, formed as a result of long periods of weathering and erosion.
The combination of all of these factors has been critical in influencing the evolution of Australia's unique landscapes and flora and fauna. The Australian biota includes extant elements of flora and fauna similar to the Gondwanan biota and Australia also has outstanding fossil records demonstrating the evolutionary sequences of these elements. As well, Australia has globally significant examples of flora and fauna that have evolved in isolation from other continents following the break-up of Gondwana. These also have outstanding expression in the continent's fossil record.
This thematic context is also associated with a unique continuity in the record of changing landscapes and life forms. The stability of the continent has resulted in preservation of sites with long-term records, or of sequences of sites that together constitute continuing records of change. These records of change include landscape remnants, fossil remnants, and stratigraphies that document climate change. For example, globally significant records of climatic change and its impacts are found in the lake sediments of a number of Australia's volcanic lakes.
The following themes and sub-themes of outstanding universal value associated with the `Continental Isolation' thematic context were identified by the Panel:
Theme: Origin and development of biota and landforms as a result of Gondwanan plate tectonics and more recent stability and long isolation
Sub-theme: Passive continental margins
Explanation: Marginal swells are characteristic of all passive continental margins. The Australian marginal swells are outstanding and exceptional in having volcanics to allow the process to be dated.
Sub-theme: Palaeoplains
Explanation: Australia has outstanding examples of ancient soils, regoliths and landforms in its ancient laterites and duricrusts.
Sub-theme: Palaeo-drainage systems
Explanation: Australia has outstanding examples of Mesozoic and older river systems extant in its landscapes.
Sub-theme: Fossils
Explanation: Cretaceous fossil sites in Victoria (particularly including fossil remnants of dinosaurs, fish and birds) are the best examples of southern high latitude Cretaceous faunas known.
Fossil sites at Riversleigh and Naracoorte provide evidence of key stages in the evolution of the Australian biota. These are linked in a temporal sequence to other sites such as the Victorian brown coal deposits.
Sub-theme: Refugia, relicts
Explanation: Australia has outstanding examples of relict biota reflecting ancient Gondwanan biota.
Sub-theme: Rainforest
Explanation: Australian rainforests are an outstanding example of ecosystems from which modern biota are derived. These rainforests are exceptionally rich in primitive and relict species, many of which are similar to fossils from Gondwana.
Theme: Evolution of landforms, species and ecosystems under conditions of stress
Sub-theme: Scleromorphy
Explanation: The Australian flora includes outstanding examples of the evolution of a diverse range of scleromorphic characteristics in response to low nutrient soils and a highly variable climate.
Sub-theme: Arid landscapes and adaptations
Explanation: Australia, as the most arid, non-polar continent on earth, has outstanding examples of arid landforms and arid-adapted biota in its sandy deserts, including the longest, longitudinal dune systems in the world.
Sub-theme: Eucalyptus-dominated vegetation
Explanation: Eucalyptus-dominated vegetation in Australia is an outstanding example on a continental scale of forest and woodland vegetation dominated by a single genus. This vegetation has evolved under stress, including conditions of high climatic variability, nutrient deficiency, and high fire frequency.
Sub-theme: Alpine
Explanation: Australia has outstanding examples of globally-unusual alpine vegetation that has developed in response to maritime conditions and poor soils.
Theme: Climate change and its impacts
Sub-theme: Records of ancient climates
Explanation: Australia has outstanding and globally significant records of past climates preserved in the sediments of a number of its lake systems.
Thematic Context: `Settlement of Australia by Hunting-and-Gathering Societies'
An important thematic context was identified associated with human settlement of the Australian continent. Australia is unique in that the entire continent has been occupied by a hunting-and-gathering society up to the time of European settlement, and that this type of society continues to play a major role in the occupation of significant parts of the continent. The Australian landscape includes globally outstanding records of this hunting-and-gathering society, including artistic expression associated with rock art sites, and religious expression associated with dreaming sites.
The unusual character of Australia's landscape and biota, described above for the `Continental Isolation' thematic context, has been important for the development of human societies on the continent. There has been a dynamic interaction between landscape, biota and human land uses involving fire, hunting and other factors. The two thematic contexts draw together several aspects of Australia's natural and cultural heritage; for example: the adaptation of hunting-and-gathering societies to the unique Australian environment, modifications by people to the landscape and the biota through the use of fire, and the exploitation of various natural resources by hunting-and-gathering societies.
The following themes and sub-themes of outstanding universal value associated with the `Settlement of Australia by Hunting-and-Gathering Societies' thematic context were identified by the Panel:
Theme: Traditional human settlement and land use
Sub-theme: Complex persistence of a hunting-and-gathering society on a single continent
Explanation: Australia provides the only example of where the hunting-and-gathering way of life has dominated an entire continent up to modern times. This way of life continues to play a significant role in the occupation of the continent, particularly in its northern and central sections.
Theme: Artistic expression
Sub-theme: Rock art
Explanation: Australia has Aboriginal art sites that represent a unique artistic achievement, as well as providing an outstanding record of human interaction with the environment over tens of thousands of years.
Theme: Religious expression
Sub-theme: Dreaming sites
Explanation: Australia provides an outstanding example of where the religious system of hunting-and-gathering societies is embodied in the landscape.
Thematic context: `European Expansion'
A major thematic context associated with the global expansion of European societies was identified by the Panel as being very important in the Australian context. Early European colonisation of the Australian continent, although motivated to a large extent by forced migration associated with the transportation of convicts, also provided ready access to abundant sources of the raw materials necessary for industrial economies. The strength of many European economies in the eighteenth and nineteenth centuries and their domination of global economic activity often stemmed in large measure from earlier colonial expansion and the opportunity to exploit natural resources from areas that had been recently colonised. The aspect of this thematic context associated with convict transportation to Australia is a globally significant example of the colonisation of an entire continent by a European-dominated culture.
The Australian goldrushes represent another important expression of the thematic context relating to `European expansion in the Eighteenth and Nineteenth Century'. The goldrushes in Australia are an outstanding example of a major global migration of people from a wide range of European and non-European cultures. This global migration was a fundamental factor influencing the development of Australia both via acceleration of the settlement of the continent, and as a result of the further integration of the country into the global economy.
The following themes and sub-themes of outstanding universal value associated with the `European Expansion'thematic context were identified by the Panel:
Theme: European expansion of the eighteenth and nineteenth centuries
Sub-theme: Forced migration - a major way in which the expansion took place
Explanation: Convict transportation to Australia is an outstanding example of how European powers initiated the colonisation of an entire continent.
Sub-theme: Land barriers as historical frontiers
Explanation: European expansion into the New World was a process of imaginative, as well as economic, appropriation in which explorers, poets, artists and photographers played a part. The first frontier, or land barrier, assumed special importance as the site of this encounter.
Sub-theme: Integration of a continent into the global economy
Explanation: The Australian goldrushes are an outstanding example of the global migrations associated with the nineteenth century goldrushes.
Theme: Masterpiece of human creative genius
Theme: Outstanding example of a type of building/technological ensemble of landscape
Thematic context: `Encounter between Cultures'
The thematic context `Encounter between Cultures', was identified by the Expert Panel as providing an important link between the previously discussed thematic contexts of `Traditional Human Settlement' and `European Expansion'. This thematic context characterises an important aspect of the history of Australia. It relates to the ongoing encounter between the traditional hunting-and-gathering societies that have occupied Australia for tens of thousands of years, and the invasion of the continent by European occupation associated with the expansion of nineteenth century European societies.
The following theme of outstanding universal value associated with the `Encounter between Cultures'thematic context was identified by the Panel:
Theme: Encounter between cultures
Explanation: Australia provides examples of the encounter between hunting-and-gathering societies and nineteenth century European societies.
While the Expert Panel considered that this theme had outstanding universal value, in contrast to the other major themes discussed, the Panel was undecided whether the best global examples of the theme undoubtedly lie within Australia.