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Professor Colin Murray-Wallace, from the School of Earth and Environmental Sciences, is pictured before his presentation with Deputy Vice-Chancellor (Research), Professor Margaret Sheil
The Quaternary period refers to the past 2.6 million years of Earth history. Although a seemingly mere instant in geological time and representing only about the last 0.06% of Earth history, the Quaternary has been characterized by episodes of profound environmental change. During this period major ice sheets up to 3 km thick have formed over large areas of the globe, sea-levels have oscillated over a vertical range of at least 120 m exposing continental shelves as dry land and there have been dramatic changes within environments that in turn have impacted on the distribution of biota in space and time. To unravel the evidence for these changes requires a multidisciplinary approach to science that involves the application of seemingly disparate techniques and analytical approaches, as well as the collective input of researchers with different expertise. Quaternary science is inherently collaborative and multidisciplinary in nature.
This presentation examines some of the evidence for changes in global sea-levels during the past 1 million years based on a study of landforms and sediments in southern Australia . The results of different geological dating methods such as amino acid racemisation in reconstructing a history of relative sea-level changes, will be briefly outlined. Amino acid racemisation involves the change in configuration of amino acids in fossils from left-handed to right-handed counterparts until an equilibrium state is obtained. The time-dependent nature of the reaction permits its application to geological dating. The dating of various shoreline deposits has also permitted an assessment of the long-term stability of parts of the Australian continent. The results reveal that parts of the Australian continent are tectonically less stable than traditionally appreciated.
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