| A map of Canada's earth materials |
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Earth Sciences Sector > Priorities > Geoscape Canada > Canada
Geoscape Canada
A map of Canada's earth materials Earth Materials - Modern sediment
Modern, or postglacial, sediment has been deposited by rivers, wind, waves, landslides, plants, and glaciers since the end of the ice ages. Where present, it forms a blanket over more extensive Ice Age sediment or bedrock.
Peat
Peat is partly decomposed plant material. It occurs in wetlands and large tracts of poorly drained land known as 'muskeg'. Peatlands are important ecosystems and store vast quantities of carbon and water. Peat bogs are mined for sphagnum moss, which is used as a soil conditioner. Farms on peatlands provide important cranberry and blueberry production.
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Figure 3. Peat exposed in a road cut, Terra Nova National Park, Newfoundland (R.J.W. Turner).
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Figure 4. Muskeg dotted with lakes, Hudson Bay lowland, Manitoba (L. Dredge).
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Mud, sand, and gravel
Mud, sand, and gravel are mainly river, stream, and beach sediments. They occur on floodplains, deltas (bodies of sediment deposited where rivers enter a lake or the sea), and shorelines. Deltas and floodplains support important wetland ecosystems and, in southern Canada, are important agricultural areas. Sand and gravel are common along Canada's lake and ocean shores. Floodplains, deltas, and beaches are prone to flooding and to liquefaction during earthquakes.
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Figure 5. Mud in tidal estuary, Vancouver, British Columbia (J.J. Clague).
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Figure 6. Sand and gravel bars, South Saskatchewan River (P. Ashmore).
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Sand
Sand underlies active and vegetated dunes. Wind-blown sand is extensive around Lake Athabasca, and in parts of southern Saskatchewan. Sand dunes also occur in coastal areas in association with sand beaches. Dunes retain little moisture, have limited nutrients, and thus support unique drought-tolerant plant communities.
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Figure 7. Active sand dunes, Great Sand Hills, Saskatchewan (S.A. Wolfe).
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Figure 8. Sand dune encroaches on playing field, Carcross, Yukon Territory (S.A. Wolfe).
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