Athabasca Dunes Ecological Reserve
Many Albertans are unaware that northern Alberta has actively migrating sand dunes. The Athabasca Dunes Ecological Reserve, together with a small dune field west of Richardson River, is the largest area of moving, or migrating sand in Alberta, as well as part of the largest dune field in Canada. This area is an excellent site to study how dunes form. Because of their remoteness and enormous size, the Athabasca Dunes are bests viewed by air as you travel from Edmonton or Fort McMurray towards Fort Chipewyan.
In this dune field, massive quantities of sand and strong winds have created an environment of blowing, shifting sand. The dunes bury and destroy jack pine forests and fill in lakes and
marshes, leaving behind a flat, barren plain. In contrast, the surrounding area presents forested hills, lakes, and marshes and is thought by many to be one of the most beautiful areas in the province.
The Athabasca dune field is seven kilometres long, 1.5 kilometres wide, and some of the dunes reach heights of 35 metres. The field consists of two enormous crescent-shaped dunes that have merged and migrated at least ten kilometres eastwards to their present location. On the dune field itself are thousands of small sinuous dunes that migrate at right angles to the northwest direction of the prevailing winds. The entire field travels southeastward at a rate of 1.5 metres per year, adding new sand to its bulk as it advances.
What sort of geological process provides an area with sand nearly 35 metres deep? The ultimate source is the granite, gneiss, and
sandstone bedrock found in northeast Alberta. Only these rock types provide massive amounts of clean sand. During the last Ice Age, glaciers
eroded this bedrock and grinded it up into vast quantities of sand. As the
glaciers melted, torrents of water poured into glacial lakes and deposited the sand. When the lakes eventually drained, the sand was dried by the winds and blown into large dunes.
This environment of blowing sand has existed for 8000 years. Any vegetation which begins to stabilize the dunes is destroyed by the wildfires so common in Northern Alberta. Geologists speculate, however, that the migration of these dunes may finally stop when they reach the Maybelle River.
Reprinted from A Traveller's Guide to Geological Wonders in Alberta by Ron Mussieux and Marilyn Nelson with permission of the authors and the Provincial Museum of Alberta