The Transition on the Coastal Fringe of Greater Australia
Beaton, J. M., Antiquity
Australia, with its wide continental shelves, is a difficult region for the study of coastal adaptations over the Transition, as so much land was drowned by the post-glacial sea level rise. What can be discerned has a place in a larger and longer-term pattern Of adaptation.
The archaeology of Greater-Australian coastal life at the Pleistocene-holocene Transition and earlier times is for the most part an underwater, or vanished, phenomenon. While we can expect important cultural and demographic adjustments were made by human populations who may have lived on palaeo-shorelines, we cannot be confident just what those adaptations, were. Still, the long and complex shore line of Greater Australia (Figure 1) is being studied actively (albeit by a relatively few archaeologists), and their studies attempt to go beyond the well-preserved confines of the later Holocene (c. 5000 b.p. and younger) archaeological record to address issues of land-form use, population history, and human ecology.
A number of themes, or at least points of reference, have emerged. These range from studies as fundamental as identifying anthropogenic middens, and dating these features, to more robust studies of site distribution and concerns with details of coastal foraging economies. Rarely do studies address the importance of coastal resources in the peopling of the continent, although Hallam (1976: 145)posited an initial coastal colonization and Bowdler (1977; 1990) developed the hypothesis and its implications. Most current reconstructions, products of exploratory research, favour interpretation based on radiometric dating and the presence/ absence indicators of human activities at the expense of studies describing more accurately the nature of those human activities and accounting for the variability between sites, within regions or between inter-regional complexes.
The Australian coastal environment
The ancient coastline of Greater Australia (Figure 1), significantly larger (depending on the position of sea-level) than the present Australian coastline which measures c. 36,700 km, extended from the equator to about 45 [degrees] S latitude, providing a very full range of ecological situations.
Around the time of the Last Glacial Maximum, extensive plains were exposed in the north, where the Barrier Reef, the Gulf of Carpentaria, and the Timor and Arafura Seas are now found. At the Pleistocene-Holocene Transition these seas had nearly reached their current positions, and straits separated Australia from New Guinea and Tasmania (Figure 2). Extensive areas of continental shelf were inundated, forming new, shallow and broad offshore environments. Where steeper off shore profiles are the rule, the coastal plains were much narrower and lateral transgression was less, depending on local profile morphology (Chappell 1976; figure 2).
In the period c. 17,000-6000 b.p., with a rise in global sea-level from c. 120 m (Fair banks 1989) to its present position (Chappell 1976), there may have been periods of stasis or even short reversals; the important trend was toward gradual vertical rise of only millimeters per year.
Procumbent and precipitous coastal profiles
The effects of marine transgression may be seen as following predictable differences between procumbent coastal profiles characterized by low relief, gentle slope, low wave-energy and rapidly weathering terrestrial land-forms, and precipitous profiles distinguished by steep slope, high relief, high wave-@energy but hard, rocky, resistant land-forms. These very different coastal profiles (and their many inter gradations) may occur adjacent to one another where bays and estuaries are formed between headlands, or they may form large tracts of comparatively uniform coastline dominated by low and sandy shores, or by steep rocky coasts. One way of considering how the evolving geomorphic configuration of different coastal land-forms might have influenced past human behaviour (as well as archaeological site-preservation or visibility) is to consider first the coastal environment. …