Delineating stratigraphic breaks at the bases of postglacial eolian dunes in central Alberta, Canada using a portable OSL reader
Article first published online: 21 MAY 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Earth Surface Processes and Landforms
Volume 37, Issue 15, pages 1603–1614, December 2012
How to Cite
Munyikwa, K., Brown, S. and Kitabwalla, Z. (2012), Delineating stratigraphic breaks at the bases of postglacial eolian dunes in central Alberta, Canada using a portable OSL reader. Earth Surf. Process. Landforms, 37: 1603–1614. doi: 10.1002/esp.3261
- Issue published online: 4 DEC 2012
- Article first published online: 21 MAY 2012
- Accepted manuscript online: 21 APR 2012 10:35AM EST
- Manuscript Accepted: 11 APR 2012
- Manuscript Revised: 29 MAR 2012
- Manuscript Received: 31 DEC 2011
- luminescence profiling;
- eolian dunes;
Temporal constraints for the Late Pleistocene deposition of eolian dunes that occur in central and northern Alberta, Canada can be provided by dating sediments from the dune bases using luminescence techniques. In places, however, the postglacial dunes overlie glaciofluvial sands that resemble the eolian deposits in texture such that demarcating the bases of the dunes is often problematic. In this study we address the problem by employing a portable optically stimulated luminescence (OSL) reader to construct luminescence profiles that depict luminescence signal variation with depth. With the portable OSL reader, measurement can be performed on bulk sediments, negating the need for laborious separation procedures to isolate pure mineral fractions, as is required in regular luminescence dating. Measurements can also be carried out in the field, permitting quicker decision making during sample collection. Results from this study, presented as depth variations of feldspar derived infrared stimulated luminescence (IRSL) signals and predominantly quartz-generated post-IR blue OSL signals, show that luminescence profiling enables one to distinguish between eolian deposits that make up the dunes from the underlying non-eolian sands. The identification of such cryptostratigraphic interfaces is made possible by differences in the dosimetric histories of the sediments. The delineation of the dune bases allows targeted sampling that yields best luminescence age approximations for the initiation of postglacial eolian deposition in the region. Luminescence profiling of eolian sequences would also, in theory, permit the identification of depositional breaks of extended duration. Copyright © 2012 John Wiley & Sons, Ltd.