A reconstruction of Lateglacial environments in the North Atlantic and Europe.

The maps shows the extent of pack ice in the Alleröd (warm) and Younger Dryas (cold) intervals. Glacier extent is during the Younger Dryas. The YD vegetation zones from N-S are tundra, steppe and forest.

 

Lateglacial vegetation

Late Pleistocene

Holocene

 

Lateglacial period in Caithness

Lateglacial: the period between deglaciation around 15 ka and the start of the Holocene, 11, 000 years ago. It includes the cold period during initial ice retreat, the warm interval of the Windermere or Alleröd Interstadial and the cold period of the Loch Lomond Stadial.

Loch Lomond Stadial : Cold period equivalent to the Younger Dryas of Europe between 12.5 and 11 ka. It was characterized by the development of small ice-caps and glaciers in the Northern Highlands. The period is named after the advance of ice from the SW Highlands to the southern shore of Loch Lomond. For more background see here

The summits of the hills in SE Caithness were probably free of glacier ice by 18 ka but the low ground probably remained under glacier ice until around 15 ka. The climatic amelioration in Scotland around 14.5 ka was remarkably rapid, possibly occurring within 50 years. Lake sediments containing organic materials began to accumulate soon after. Temperatures rose close to present values and a complex mosaic of vegetation communities developed across northern Scotland.

After 12.75 ka conditions deteriorated and there was a return to rather arid arctic conditions around 12.5 ka. Permafrost became established on both high and low ground. Rates of debris production from rock walls increased markedly and large volumes of glacial deposits were mobilised by solifluction to form thick deposits on valley floors.