Click on map to view cross-sections

When explaining groundwater its physical and chemical characteristics and why it behaves as it does, it helps to have an understanding of the geology and the geologic formations that lie beneath the surface in addition to the general topography.

In most locations, Alberta is covered by a layer of overburden composed of glacial tills, sands, silts and clays that have accumulated since the last ice age, and were initially formed after the glaciers carved the landscape and then melted away. The overburden layer can range from less than a metre in depth to hundreds of metres. Availability of groundwater in the overburden layer depends on the geometry of sandy layers that can be very irregular. This makes it difficult to find reliable wells in these shallower deposits.

Below this overburden layer lies the sedimentary bedrock layers, where some of the deeper sandstone aquifers are found.

The following cross-sections on the map show the general geologic formations in Alberta that lie below the surface overburden layers. Click on th lines to see them, or use these links:

Three cross-sections, labeled

• A-A' (Northern Alberta)
• B-B' (Central and Eastern Alberta)
• C-C' (Southern Alberta)

Credit: The Geological Highway Map of Alberta (Second Edition, 1981) , produced by the Canadian Society of Petroleum Geologists.