Parallel Roads of Glen Roy recognised as one of the world’s top geology sites

The site, which is part of NatureScot’s Glen Roy National Nature Reserve, is home to an iconic suite of glacial lake shorelines that informed the development of Glacial Theory in the 19th century. Three shorelines, or ‘parallel roads’, are evidence that glaciers were once in an area where none exist today.

Two other significant geology sites have been selected, including the Rum Igneous Complex, in NatureScot’s Rum National Nature Reserve, which is regarded as the internal plumbing of one of Scotland’s most recently active (60-million-year-old) volcanoes in which chromium and the precious metal platinum accumulated in chambers of molten magma.

The third site is Barrow Zones, in the Scottish Highlands, a series of rock layers, in the Glen Esk area, that were once mud on an ancient ocean floor. Changes in the mineral content of rocks, up Glen Esk, shows that they experienced increasingly higher pressures and temperatures, in a north-westerly direction, when plate tectonics brought the geological foundations of Scotland together around 470 million years ago.

They have been selected for the International Union of Geological Science's (IUGS) second list of 100 geological heritage sites. The main goal of this collaborative program led by the IUGS is to give the highest recognition to those sites that are essential for the geological sciences.

As with the First 100, these sites receive IUGS recognition because they are of the highest scientific value. They are the world’s best demonstrations of geological features and processes. They are the sites of fabulous discoveries of the Earth and its history.

The full list was announced during the 37^th International Geological Congress in Busan, Republic of Korea on 27 August 2024.

More than 700 experts from 80 nations and 16 international organizations participated in this global endeavour, which consolidates the recognition of geological heritage by the IUGS.

Siccar Point in the Scottish Borders and Moine Thrust in the northwest Highlands were recognised in the First 100 IUGS Geological Heritage Sites in 2022. We will have to wait until 2026 to find out if sites in Scotland will be added to the Third 100 Geological Heritage Sites.

NatureScot Geomorphologist, Dr Christina Wood said: “It’s fantastic to see three Scottish sites being recognised for their internationally important contributions to geological science. 

“We’re particularly proud that both the Parallel Roads of Glen Roy and the Rum Igneous Complex are located on NatureScot’s National Nature Reserves.

“Glen Roy and neighbouring Glen Spean have stimulated geological debate from the early-nineteenth century to the present day. Particular highlights are three shorelines, or 'Parallel Roads', visible along the flanks of Glen Roy at altitudes of 260m, 325m and 350m above sea level. The lakes that created the shorelines were dammed by glaciers as they advanced and retreated.

“The Parallel Roads provided convincing evidence for the former existence of glaciers in an area where none exist today, thus supporting Agassiz’ theory of continental glaciation during a geologically recent Ice Age.

“It’s vital we protect and conserve these special places for future generations to learn from and enjoy and we hope that many more people will continue to explore and experience the wonders of Scotland’s truly magnificent geological heritage.”