Lakes of the Canadian Shield

The Canadian Shield is the ancient core of the North American Continent. It is composed mainly of highly metamorphosed granite, with smaller areas of metamorphosed sedimentary and igneous rocks and some areas of relatively horizontal but still quite ancient sedimentary rocks. These rocks are generally quite resistant to weathering and erosion, but have been subjected to intense and repeated glaciation. The topography of the landscape reflects the interplay between rock resistance and glacial action, with areas of relatively weaker rocks having been eroded to lower elevations while more resistant rocks form topographic highs. The distribution of lakes strongly reflects patterns of rock resistance. Faults and bedding layers in rocks tend to cause many lakes in the shield to be long and narrow. Nowhere is this more evident in maps of the Shield than in Lake Manicoua-gan, a reservoir constructed in the 1970s and forms a circle roughly 70 km in diameter. The circular structure is the result of a meteor collision 214 million years ago. The deepest lake in Quebec, Pingualuit Crater (252 m deep) is also the result of a meteor impact. Lake Mistassini is another example of a structurally-controlled lake. It is more than 2000 km2 in area, consisting of a series of northwest-southeast trending arcs paralleling the underlying bedrock structures.

The number of lakes in the Canadian Shield is very large. Ontario and Quebec alone list over 12 000 lakes greater than 3 km2 in area; the number of smaller lakes is much larger (Refer to 'see also' section). They occur throughout the Shield region, but are especially numerous in the highlands of Quebec and Labrador, the Ungava peninsula, northern Manitoba and Saskatchewan, Nunavut, and the eastern portions of the Northwest Territories. They are less abundant in the Hudson Bay lowlands of northern Ontario and eastern Saskatchewan.

The age and mineralogical composition of Shield rocks means that they are relatively deficient in calcium. In addition, the cool temperatures of the region and widespread coniferous forest lead to development of highly acidic soils. Thus, the lakes of the region tend to be acidic and highly oligotrophic. In addition, of course, they are ice-covered for much of the year.

Continue reading here: The Great Lakes Region

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  • mira
    Why are the lakes in the canadian shield good for you?
    11 months ago
  • codi wilson
    What are the 3 great lakes that border the canadian shield region?
    12 months ago
    How many lakes are in canadian shield in total?
    12 months ago
  • osman
    What arresouth lakes of candian shield?
    1 year ago
  • kristian
    What does the Canadian shield lack?
    2 years ago
  • Arnor
    How can you save the Canadian sheild?
    2 years ago
  • oliviero
    Is michigamme lake a canadian shield lake?
    2 years ago
  • carl
    Is the maligne ake in the canadian sheild?
    2 years ago
  • rudibert greenhand
    What are some lakes called in the canadian shield?
    2 years ago
    What where the canadian shield lakes made by?
    2 years ago
  • Roan McMillan
    How many lakes are in the canadian sheikld?
    2 years ago
  • Senay Luwam
    How are lakes in the canadian shield formed?
    2 years ago
  • Sabrina
    How many lakes in canadian shied?
    2 years ago
  • uta
    What is a typical canadian shield lakes?
    2 years ago
  • delmo
    What is a canadian shield lake?
    2 years ago