The glacial geomorphology of the Loch Lomond (Younger Dryas) Stadial in Britain: a review

Abstract

This paper systematically reviews the glacial geomorphological evidence of the Loch Lomond Stadial (LLS; Younger Dryas) glaciation in Britain (12.9-11.7 ka). The geomorphology of sub-regions within Scotland, England and Wales is assessed, providing the most comprehensive synthesis of this evidence to date. The contrasting nature of the evidence at the local scale is reviewed and conceptual themes common to multiple sub-regions are examined. Advancements in glaciological theory, mapping technologies, numerical modelling and dating have been applied unevenly to localities across Britain, inhibiting a holistic understanding of the extent and dynamics of the LLS glaciation at a regional scale. The quantity and quality of evidence is highly uneven, leading to uncertainties regarding the extent of glaciation and inhibiting detailed analysis of ice dynamics and chronology. Robust dates are relatively scarce, making it difficult to confidently identify the limits of LLS glaciers and assess their synchroneity. Numerical models have allowed the glacier-climate relationships of the LLS to be assessed but have, thus far, been unable to incorporate local conditions which influenced glaciation. Recommendations for future research are made that will allow refined reconstructions of the LLS in Britain and contribute to a more comprehensive understanding of glacier-climate interactions during the Younger Dryas. #

Topographic controls on plateau icefield recession: insights from the Younger Dryas Monadhliath Icefield, Scotland

“…Evidence for a strong topographic control on glacier recession patterns highlights the difficulties of using moraine sequences, such as those reported here, in isolation without considering topographic factors, to extract detailed climatic information (Kuhn et al ., ; Greene, ; Lukas, ; Barr and Lovell, ). By accounting for these topographic factors, we are able to make two key conclusions regarding events during deglaciation in the Monadhliath and Scottish Younger Dryas climate: (i) evidence for major readvances during recession is limited, corroborating findings from the Northwest Highlands (Lukas and Benn, ), with the potential for both geometric and climatic controls on recession rates; and (ii) the even spacing of moraines in valleys of consistent bed gradient and the presence of recessional moraines on the plateau suggests that climate warming was gradual rather than rapid, as has been suggested elsewhere (Bickerdike et al ., ).…”

“…Ivy‐Ochs et al ., ; Larsen et al ., ; Mangerud et al ., ). In upland Britain, ice mass expansion left a detailed record of well‐preserved glacial landforms, in particular moraines (Bickerdike et al ., ; Chandler et al ., , , and references therein). The Younger Dryas record in Scotland is therefore important for examining the response of ice masses to rapid climate change at the end of the Last Glacial–Interglacial Transition (LGIT).…”

On the timing of retreat of the Loch Lomond (‘Younger Dryas’) Readvance icefield in the SW Scottish Highlands and its wider significance

“…The reconstructed glacier limits represented in Figure 1 are based on extensive mapping of a range of glacigenic landforms and sediments, including the distribution of well-defined morainic or other glacigenically formed mounds (in older literature commonly and collectively referred to as 'hummocky moraine') and/or prominent terminal moraines or other ice-marginal features, such as outwash fans and deltaic sequences. Overviews of the collective geomorphological evidence on which the empirical ice limits are based can be found in (inter alia) Sissons (1974), Sutherland (1984), Benn (1997), Golledge (2010), Bickerdike et al (2016Bickerdike et al ( , 2018aBickerdike et al ( , 2018b and Chandler (2018).…”

A spatially-restricted Younger Dryas plateau icefield in the Gaick, Scotland: Reconstruction and palaeoclimatic implications

“…Moreover, the morphostratigraphic framework will facilitate extrapolation of radiometric dates across the Gaick from any glacier limits that become better constrained in the future, which is necessary (at least to some degree) in all localities across Scotland (cf. Lukas, 2006;Boston et al, 2015;Bickerdike et al, 2018a).…”