Glacial geomorphology of the Gaick, Central Grampians, Scotland

Abstract

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 km 2. 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.

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

“…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).…”

Processes of ‘hummocky moraine’ formation in the Gaick, Scotland: insights into the ice‐marginal dynamics of a Younger Dryas plateau icefield

“…Moraines and associated sediment-landform assemblages in the Gaick were mapped using a combination of geomorphological field mapping at 1:10 000 scale and aerial photograph interpretation, following standard procedures (Chandler et al 2018(Chandler et al , 2019b. To ensure that the location and planform geometry of individual moraines were represented accurately and precisely on the maps, the final mapping of the moraines was performed digitally.…”

“…In recent re‐investigations of the glacial geomorphology and glacial history of the Gaick, we recognized a distinct morphostratigraphical signature in the western Gaick that differs markedly from sediment–landform assemblages found elsewhere in the area (Chandler et al . , b). On the basis of this distinct sediment–landform signature and independently tested morphostratigraphical criteria for the Scottish Highlands (Lukas ; Boston et al .…”

“…2019a) consist of mounds and short ridge fragments that reach heights of ~2 to 15 m, lengths of ~10 to 250 m and widths of ~10 to 85 m. They are widespread features in the valley bottoms and on the lower ~50–150 m of adjacent slopes of the upper western catchments (Chandler et al . , b), and individual moraine mounds and ridges give rise to a hummocky appearance at ground level (Fig. ).…”

“…The map extract is adapted from the geomorphological map presented by Chandler et al . (2019b). Underlying hillshade relief model was derived from the NEXTM ap Britain™ data set (Intermap Technologies Inc.).…”