Struie Channels

Also within

Ross and Cromarty County

Condition (NatureScot)

Geology & landscape

Geological Feature: Esker · Geological Period: Quaternary

Landscape processes: Glacial

Description

Struie Channels The Struie Channels SSSI is located 8 kms north of Alness in Strathrory, between the Dornoch and Cromarty Firths. The Struie Channels were formed by glacial meltwater rivers at the end of the last ice age or ‘Quaternary’ period. The ice sheet occurred in the Late Devensian period, about 14,000 to 13,000 years ago. The glacial meltwater channels were formed in cavities below the glacier where meltwater streams and rivers formed channels in the sediment. The channels began to form as conditions became warmer and the ice began to melt. Large quantities of water were released which formed rivers on the surface of the glacier, within and underneath it. When the ice finally retreated the channels that were previously underneath the ice were left as ‘dry’ channels on the hillside. The site contains channels formed both underneath and at the edge of the glacier. It also contains sub-parallel meltwater channels which bend, curve and link across the landscape, just like rivers do today. Their parallelism suggests that they formed at, or near the edge of, the glacier. The western side of the site contains a spectacularly large channel as well as small linked channels. The largest of these meltwater channels is up to 33 m deep, 89 m wide and 2.5 km long. The SSSI is an important example of meltwater channels because they are rare in northern Scotland and it is therefore of national importance for both education and research into glacial processes in Scotland during the last ice age. The channels also complement the nationally important esker systems (glacial meltwater deposits) of the Moray Firth lowlands.