Central and Eastern Grampian Highlands

The Central and Eastern Grampian Highlands comprise a tract of extensive mid-level to high-level palaeosurfaces unlike anywhere else in the Scottish Highlands, forming a major west–east drainage divide between the Dee and Tay catchments. This undulating upland comprises broad gentle slopes, shallow plateau valleys and upstanding rounded hills with a remarkable accordance of summit elevations. The area was overrun by successive Quaternary ice sheets but the erosional imprint is selective and linear, with well-defined glacial troughs alongside valley systems showing only limited glacial modification. The plateaux were occupied by cold-based ice within the last Scottish Ice Sheet, feeding into faster-flowing glaciers in the surrounding Dee, Tay and Strathmore valleys. During the Loch Lomond Stade (~12.9–11.7 ka), local plateau icefields sourced outlet glacier lobes in many valleys, while cirque glaciers occupied topoclimatically favoured sites. Most end, lateral and recessional moraines were deposited at this time. Solifluction lobes and terraces festoon upper slopes: those on granite-derived regolith are relict, Lateglacial stone-banked lobes; those on metasedimentary rocks are active under present conditions. In the Eastern Grampians, granite intrusions form prominent hills, some bearing summit tors and blockfields. Large-scale paraglacial rock slope failures are located on steeper slopes at trough heads and margins. Localised debris-flow activity continues to rework the drift mantle, triggered by exceptional rainstorms.