Glacial geomorphology relating to the Loch Lomond Stadial (Younger Dryas) in Britain is used to construct five glacial landsystem models. These landsystems lie on a continuum of increasing ice thickness and decreasing topographic control and typify the principal styles of glaciation during the stadial. The landsystems comprise: the cirque/niche glacier landsystem, the alpine icefield landsystem, the lowland piedmont lobe landsystem, the plateau icefield landsystem and the icecap landsystem. Geomorphological features representing the icecap landsystem are present only at the centre of the West Highland Glacier Complex, which was flanked primarily by satellite alpine and plateau icefields. The cirque/niche glacier landsystem was present predominantly in areas that experienced conditions only marginally favourable for glacier development at peripheral sites. Three styles of glacier retreat are recorded by the geomorphology: active, two-phase and uninterrupted retreat. Of these, active retreat appears to be most widespread within the Loch Lomond Stadial limits. These retreat styles reflect a combination of climatic and topographic conditions, coupled with local factors influencing the preservation of landforms from which retreat dynamics can be inferred. Likewise, the distribution of landsystems was influenced by an interplay between topography and climate, with glacier formation being facilitated in locations where topographical conditions aided in the accumulation of snow. The pattern also supports the existence of previously recognized northward and eastward precipitation gradients across Britain during the stadial.

The Loch Lomond Stadial (LLS) was an abrupt period of renewed cooling between 12.9 and 11.7 ka and has long been associated with the regrowth of glaciers in much of upland Britain. Mapping the glacial landforms associated with this period has been undertaken for over a century, but in a non-systematic nature and at specific locations. In this paper, glacial geomorphology associated with the LLS in Britain has been compiled from the published literature into a glacial map and accompanying geographical information system database that is available electronically as supplementary information. A variety of scales have been used to best represent the evidence in the database. Map A is at 1:310 000; B, C, D, E, F, J, L, M and O are at 1:175 000; K, N, P are at 1:100 000 and G, H and I are at 1:50,000. The database contains over 95,000 individual features, which are organised into thematic layers and each attributed to its original citation. The evidence includes moraines, drift and boulder limits, drift benches, periglacial trimlines, meltwater channels, eskers, striations and roches moutonneés, protalus ramparts and ice-dammed lakes. Creation of this database overcomes the drawbacks posed by the non-systematic nature of previous mapping output from studies of LLS glaciation. It is intended to be a catalyst for future research in this area, with especial significance for regional palaeoglaciological and palaeoclimatic reconstructions of the Younger Dryas and numerical modelling. ARTICLE HISTORY

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. #