Did large ice caps persist on low ground in north-west Scotland during the Lateglacial Interstade?
Article first published online: 24 OCT 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Journal of Quaternary Science
Volume 27, Issue 3, pages 297–306, 1/27 April 2012
How to Cite
Ballantyne, C. K. and Stone, J. O. (2012), Did large ice caps persist on low ground in north-west Scotland during the Lateglacial Interstade?. J. Quaternary Sci., 27: 297–306. doi: 10.1002/jqs.1544
- Issue published online: 10 APR 2012
- Article first published online: 24 OCT 2011
- Manuscript Accepted: 28 AUG 2011
- Manuscript Revised: 25 AUG 2011
- Manuscript Received: 27 APR 2011
- Cosmogenic 10Be exposure dating;
- cosmogenic 10Be production rates;
- deglaciation chronology;
- Wester Ross Readvance
Recent research based primarily on exposure ages of boulders on moraines has suggested that extensive ice masses persisted in fjords and across low ground in north-west Scotland throughout the Lateglacial Interstade (≈ Greenland Interstade 1, ca. 14.7–12.9 ka), and that glacier ice was much more extensive in this area during the Older Dryas chronozone (ca. 14.0 ka) than during the Younger Dryas Stade (ca. 12.9–11.7 ka). We have recalibrated the same exposure age data using locally derived 10Be production rates. This increases the original mean ages by 6.5–12%, implying moraine deposition between ca. 14.3 and ca. 15.1 ka, and we infer a most probable age of ca. 14.7 ka based on palaeoclimatic considerations. The internal consistency of the ages implies that the dated moraines represent a single readvance of the ice margin (the Wester Ross Readvance). Pollen–stratigraphic evidence from a Lateglacial site at Loch Droma on the present drainage divide demonstrates deglaciation before ca. 14.0 ka, and therefore implies extensive deglaciation of all low ground and fjords in this area during the first half of the interstade (ca. 14.7–14.0 ka). This inference appears consistent with Lateglacial radiocarbon dates for shells recovered from glacimarine sediments and a dated tephra layer. Our revised chronology conflicts with earlier proposals that substantial dynamic ice caps persisted in Scotland between 14 and 13 ka, that large active glaciers probably survived throughout the Lateglacial Interstade and that ice extent was greater during the Older Dryas period than during the Younger Dryas Stade. Copyright © 2011 John Wiley & Sons, Ltd.