Introduction: Australian geomorphology into the 21st century

Australian Landscapes is at least the third edited volume to be devoted to Australian geomorphology in the last half-century, two others being Landform Studies from Australia and New Guinea (Jennings & Mabbutt 1967) and Landform Evolution in Australasia (Davies & Williams 1978). There is a strong thread running between those two volumes and this one: the second volume marked the retirement of Joe Jennings, who was one of the editors of the first volume, and this volume honours one of the editors of the second, Martin Williams, along with John Chappell; both John and Martin retired recently. The legacy of Joe Jennings, who supervised the PhD research of both Martin and John, is summarized briefly in an Appendix to this Introduction. The fact that we, the editors of this current volume, were supervised in our PhD research by John (B.P.) and Martin (P.B.) continues that intertwining of threads. The apparent directness of the links between these three volumes is matched in some ways by the enduring nature of some themes in the three volumes, themes that have been particularly Australian (or at least Gondwanan) for more than half a century. Thus, at least seven papers in the 1967 volume emphasize the antiquity of the Australian landscape, with statements such as ‘The pattern of relief imposed by structure has persisted at least since the Mesozoic’ (Twidale 1967, p. 95). That clear grasp of landscape antiquity, along with parallel landmark Gondwanan contributions by researchers such as King (1962), contrasts clearly with the viewpoint of (at least some of) contemporary work in the Northern Hemisphere, such as that of Thornbury (1969), who argued that landscapes are probably no older than the Pleistocene. The emphasis on landscape antiquity continued in the Davies & Williams (1978) volume, in particular with the paper by Ollier (1978) on the evolution of the eastern Australian highlands, a theme that emerged in the late 1970s and early 1980s, particularly with the work of Bob Young (e.g. Young 1983). A key difference between the Jennings & Mabbutt (1967) volume and that of Davies & Williams (1978) is the increasingly routine application of geochronology in the latter. The Jennings & Mabbutt (1967) volume included three radiocarbon ages in the paper by Davies (one of them apparently reported for the first time in that paper), one previously published radiometric age on granite in Galloway’s paper, one previously published radiocarbon age in the paper by Ollier, and a few tens of radiocarbon ages in the papers by Fairbridge and Gill (not unexpectedly in the case of Gill, given his central role in establishing the radiocarbon technique in Australia). By the time of the Davies & Williams (1978) volume, the application of quantitative dating techniques was much more routine and so geochronology is much more a feature of that volume. Emphases on age(s) of landscapes and landforms and on rates of erosion or denudation are, of course, enduring themes in geomorphology. A key development between the Davies & Williams (1978) volume and the present one has been the emergence of new and exciting geochronological tools. With the advent of these new tools, including cosmogenic nuclide analysis, luminescence dating techniques, accelerator mass spectrometry conventional radiocarbon determinations, and stable isotope-based approaches to landscape dating that exploit Australia’s northward drift throughout the Late Mesozoic and Cenozoic, the discipline is much better placed to set landscapes and their evolution in geochemically or geophysically determined quantitative age frameworks. Thus, this volume reports on a range of studies that continue the long-standing theme of the antiquity and stability of the Australia continent. Kaolinite from weathering profiles from the Yilgarn craton have yielded Cenozoic and older ages (Chivas & Atlhopheng), pointing to considerable stability of the craton and the slow rates of erosion that characterize much of inland Australia. The extensive dataset of Heimsath et al. teases out that theme using cosmogenic nuclide analysis. Their data point to a strong dependence between erosion rate and climate, a dependence that is identified in many (but not all) studies of the relationship