US EPA

1282855 

Journal Article 

Readvance of the last British-Irish ice sheet during Greenland Interstade 1 (GI-1); the Wester Ross Readvance, NW Scotland 

Ballantyne, CK; Schnabel, C; Xu, S 

2009 

1 

Quaternary Science Reviews
ISSN: 0277-3791 

Elsevier 

International (III) 

28 

9-10 (May 2009) 

783-789 

Fourteen samples obtained from Torridon sandstone boulders on four moraines marking the limit of the Wester Ross Readvance (WRR) in NW Scotland yielded tightly clustered (super 10) Be exposure ages confirming contemporaneous or penecontemporaneous moraine deposition. Collectively, the 14 samples yield mean ages of 13.5+ or -1.2 ka to 14.0+ or -1.7 ka, depending on choice of geomagnetic scaling and sampling surface erosion rates. All fourteen moraine ages are significantly younger than an age of ca 16.3 ka previously proposed for the WRR, and also younger than most samples obtained from rock outcrops within the WRR limits. The ages obtained for the WRR moraines appear to confirm that a substantial cover of glacier ice persisted over low ground in NW Scotland during at least the early part of the Lateglacial Interstade ( nearly equal Greenland Interstade 1). We infer that the WRR probably occurred in response to rapid short-lived cooling during the Older Dryas climatic reversal ( nearly equal Greenland Interstade 1d), though the possibilities that the WRR represents ice-margin response to a later climatic reversal during the Lateglacial Interstade or stabilization and readvance of the ice margin following rapid offshore calving cannot be discounted. 

Weichselian; upper Pleistocene; metals; ice sheets; glaciation; Cenozoic; Older Dryas; British-Irish ice sheet; upper Weichselian; Pleistocene; Scotland; glacial extent; United Kingdom; clastic sediments; alkaline earth metals; beryllium; Europe; Great Britain; absolute age; glacial geology; isotopes; Be-10; sediments; boulders; ice-marginal features; Quaternary; radioactive isotopes; Western Europe; interstadial environment