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Superimposed on ancient landscape elements, the Inverness region includes a palimpsest of subglacial landforms formed during successive Late Devensian ice movements. It contains a particularly rich and diverse set of sediments and landforms created close to retreating glacier margins, together with the legacy of a major oscillating tidewater outlet glacier. At least five phases of glaciation have been recognised, although they remain poorly constrained temporally. The region includes well-documented buried glacial rafts of arctic shelly clay, two internationally important localities where organic deposits pre-date the last ice sheet, and a good geomorphological record of Late Glacial sea-level change.

Lithostratigraphical studies coupled with the development of new dating methods has led to significant progress in understanding the Late Pleistocene terrestrial record in Scotland. Systematic analysis and re-evaluation of key localities have provided new insights into the complexity of the event stratigraphy in some regions and the timing of Late Pleistocene environmental changes, but few additional critical sites have been described in the past 25 years. The terrestrial stratigraphic record remains important for understanding the timing, sequence and patterns of glaciation and deglaciation during the last glacial/interglacial cycle. Former interpretations of ice-free areas in peripheral areas during the Last Glacial Maximum (LGM) are inconsistent with current stratigraphic and dating evidence. Significant challenges remain to determine events and patterns of glaciation during the Early and Middle Devensian, particularly in the context of offshore evidence and ice sheet modelling that indicate significant build-up of ice throughout much of the period. The terrestrial evidence broadly supports recent reconstructions of a highly dynamic and climate-sensitive British-Irish Ice Sheet (BIIS), which apparently reached its greatest thickness in Scotland between 30 and 27ka, before the global LGM. A thick (relative to topography) integrated ice sheet reaching the shelf edge with a simple ice-divide structure was replaced after the LGM by a much thinner one comprising multiple dispersion centres and a more complex flow structure.

This paper reviews the changing environments, developing landforms and terrestrial stratigraphy during the Early and Middle Pleistocene stages in Scotland. Cold stages after 2.7 Ma brought mountain ice caps and lowland permafrost, but larger ice sheets were short-lived. The late Early and Middle Pleistocene sedimentary record found offshore indicates more than 10 advances of ice sheets from Scotland into the North Sea but only 4-5 advances have been identified from the terrestrial stratigraphy. Two primary modes of glaciation, mountain ice cap and full ice sheet modes, can be recognised. Different zones of glacial erosion in Scotland reflect this bimodal glaciation and the spatially and temporally variable dynamics at glacier beds. Depths of glacial erosion vary from almost zero in Buchan to hundreds of metres in glens in the western Highlands and in basins both onshore and offshore. The presence of tors and blockfields indicates repeated development of patches of cold-based, non-erosive glacier ice on summits and plateaux. In lowlands, chemical weathering continued to operate during interglacials, but gruss-type saprolites are mainly of Pliocene to Early Pleistocene age. The Middle Pleistocene terrestrial stratigraphic record in Scotland, whilst fragmentary and poorly dated, provides important and accessible evidence of changing glacial, periglacial and interglacial environments over at least three stadial-interstadial-interglacial cycles. The distributions of blockfields and tors and the erratic contents of glacial sediments indicate that the configuration, thermal regime and pattern of ice flow during MIS 6 were broadly comparable to those of the last ice sheet. Improved control over the ages of Early and Middle Pleistocene sediments, soils and saprolites and on long-term rates of weathering and erosion, combined with information on palaeoenvironments, ice extent and sea level, will in future allow development and testing of new models of Pleistocene tectonics, i

The Gaick is an enigmatic glaciated landscape in the Central Grampians, Scotland, dominated by an expansive dissected plateau. Previous studies have postulated widely differing interpretations of the glacial landforms and current understanding of the glacial events in this area is partly restricted by the absence of detailed glacial geomorphological mapping. To address this issue, we present a comprehensive 1: 46,000-scale glacial geomorphological map, covering an area of ∼520 km2. A combination of detailed field mapping and interpretation of aerial photographs and Digital Surface Models (DSMs) has revealed a variety of glacial, periglacial and fluvial landforms, including an abundance of moraines and meltwater channels within valleys. We also identify a glacial sediment-landform assemblage, dissected glaciogenic material, that has not previously been reported in the Scottish Highlands. The geomorphological map provides the necessary foundation for elucidating the extent, dynamics and timing of former glaciation in the area.

The Monadhliath Mountains comprise of an extensive area of plateau in the Central Highlands of Scotland, which is bounded to the north by the Great Glen and to the south by Strathspey. The region is located immediately to the northwest of the Cairngorm Mountains, to the north of Creag Meagaidh and to the northeast of the Ben Nevis Range, forming a nearly continuous area of upland from Glen Roy westwards to where the A9 crosses Slochd Summit (Fig. A). The upland consists of rounded summits and is dissected by at least twenty-five key catchments. It is divided to an extent in two by the Corrieyairack pass, forming a much smaller area of upland in the west, to the north of Glen Roy, and a larger (main) plateau in the central and eastern part of the region. This main plateau slopes downwards towards the north, with the altitude of the plateau edge ranging from 900 m in the south, with individual summits as high as 945 m (Carn Dearg, NH 636 024), to 600 m in the north. As a result, the main watershed runs from west to east across the southern edge of the plateau, and this asymmetry is manifest in short, steep catchments on the south side of the plateau, with the majority of the plateau draining northwards or eastwards within large catchment areas. Valleys draining the plateau to the south tend to have steep backwalls separating the valley floor from the plateau above whilst catchments in the north gently rise onto the plateau, often with no backwall. This asymmetry has significantly affected the form and dynamics of glaciers in the region and is discussed further by Boston (this guide).

The Speyside area of the southern Monadhliath Mountains displays an exceptionally welldeveloped suite of landforms and deposits that formed during the latter stages of Late Devensian glaciation in this part of Scotland (Young, 1978; Hinxman and Anderson, 1915; Merritt et al., this guide). This section of the field guide describes the glacial landforms and sediments present in the valley of Raitts Burn (NH 760 047 – 796 036). The burn flows south-eastwards across the north-western flank of Strathspey to join the valley of the River Spey c. 3 km downstream of Kingussie (Fig. 1). Exposed in the cliff sections cut by the burn is a sequence of rhythmically laminated clays, silts and sands, interbedded with ice-proximal diamictons and matrix-rich gravels (Auton 1998; Phillips and Auton, 2000). Detailed examination of the complex suite of sedimentary and glacitectonic structures developed within these sediments has revealed a complex sequence of depositional and deformational events recording the formation and overriding of an ice-dammed lake (Phillips and Auton, 2000). The glacial landform record in the area clearly indicates that this complex pattern of meltwater ponding and ice advance into the lake occurred in response to active ice retreat during the deglaciation of the Raitts Burn basin.

The location of the Monadhliath Mountains in the middle of the Grampian Highlands places them in a central zone with respect to ice flow pathways during the maximum extent of the last British and Irish Ice Sheet (BIIS) in the Late Devensian. At the ice sheet maximum the Scottish mainland was probably entirely submerged beneath ice, which flowed north-westwards out to the continental shelf break, merging with Scandinavian ice occupying the North Sea basin (Bradwell et al., 2008). This period roughly equates with the global Last Glacial Maximum (LGM), 28,000-22,000 years ago (Mix et al. 2001). The most recent model of the BIIS (Clark et al., 2012) places the Monadhliath Mountains immediately to the east of the main north-south ice divide of the Scottish ice sheet, and north of a subsidiary west-east divide, centred over the East Grampian and Cairngorm mountains. Geomorphological evidence for ice streaming in the Great Glen and Spey Valley to the northeast and southwest of the Monadhliath massif indicates a general ice flow direction towards the northeast across the region, supporting this ice-divide positioning.

— Evidence of both rising and falling relative sea levels and glacitectonic movements is preserved in two formations of raised glaciomarine deposits that were laid down in front of an QSR oscillating •grounded' tidewater glacier in the Inverness Firth. These changes occurred during the latter stages of the disintegration of the Moray Firth ice-stream, one of the major ice streams that drained the British main Late Devensian ice sheet. Most of the glaciomarine deposits antedate a sequence of glacio•isostatically tilted Late Devensian marine shorelines and associated littoral and estuarine deposits. The shorelines began forming at about 13,000 BP and record a progressive fall in relative sea level. A new model for the deglaciation of the Moray Firth region is proposed after a critical appraisal of published accounts of both onshore and offshore Quaternary sequences. The disintegration of the Moray Firth ice stream involved several rapid phases of retreat to pinning points, caused by iceberg calving and triggered by rising global sea level. Each retreat was followed by minor readvances or stillstands, possibly caused by short-lived accelerated periods of glacio-isostatic rebound and concomitant temporary falls in relative sea level. Two such events occurred in the Inverness Firth: the Ardersier Oscillation and the Alturlie Stillstand. Substantial differences (lower relative sea levels, later deglaciation) are apparent between the pattern of ice-retreat in the Moray Firth region and published accounts of the deglaciation of the Irish Sea basin. These differences require a reassessment of some current hypotheses concerning the disintegration of major ice streams associated with high relative sea levels. Furthermore, geological and geomorphological evidence suggesting both rising and falling sea levels in the Inverness area, prior to ca. 13,500 BP, is not fully compatible with recently published computer simulations of the dissolution of the British main Late Dev