Dating moraine deposits using luminescence from rock surfaces

• Applicant: Dr. Eike F. Rades
• Subject Area: Palaeontology
• Term: from 2017 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 352241072

In this project, I will investigate the timing of glacial expansion by applying the very new technique of luminescence surface dating to glacial moraine deposits and so derive reliable deposition ages of individual boulders. Knowledge of the timing and extent of past glaciations is crucial to the correct interpretation and correlation of past changes in climate and their impacts on the global environment. Moraine deposits are widespread indicators of the presence and extent of glaciations. Until recently, only radiocarbon dating could be used to date such moraine deposits, but the low age range (~50 ka) and the frequent lack of suitable organic remains have limited successful application. As a result, only relative regional chronologies are available in most areas. More recently, cosmogenic nuclide exposure dating has allowed direct dating of morainic material. However, despite promising results precise dating is often inhibited by large age differences between results from individual boulders from the same moraine. Recently, the application of luminescence dating has been extended to rock surfaces. Luminescence depth profiles from boulder surfaces can provide information about the history of exposure to daylight prior to burial, as well as test for full resetting of the signal. The luminescence ages derived from such surfaces can be safely assumed to provide the age of the deposition of the moraine. In appropriate circumstances, profiles can also provide information on multiple exposures and burials. This new method of dating glacial deposits will enable researchers to date formerly undateable sites and provide an alternative option for others.With my background in luminescence and cosmogenic nuclide dating and my experience with dating glacial deposits, I am particularly well-suited to undertake this project The research will be undertaken at the world-leading luminescence laboratory where the new rock-surface dating method was developed.In summary, this project will (i) test the reliability of the new method, and provide new ages for glacial advances in the European Alps and Southern Sweden, (ii) provide new knowledge of the relative importance of transportation process of large clasts in glacial environments, and (iii) provide information about past surface exposure to guide the selection of the most suitable boulders for cosmogenic nuclide dating, so improving the reliability and extending the application of this well established method.

• DFG Programme: Research Fellowships
• International Connection: Denmark
• Hosts: Dr. Mayank Jain; Professor Dr. Andrew Murray