Waterton Lakes National Park

A Virtual Field Trip

 

Geology and Landforms

 

  1.5 billion years ago, Waterton Lakes National Park's ancient rocks were first created. One can see evidence of ancient seas, glaciers, volcanoes, and rivers. Many of the most beautiful sites in Waterton, such as Red Rock Canyon are examples of the geological processes that once occurred there. Much of Waterton's most beautiful scenery was carved by the fingers of four ancient glaciers.

The bedrock geology of the Waterton Region is shown in the map below. The mapping units are generalized by age and are defined in the table below the map. The precambian rock units (1 and 2) include the formations that make up the Purcell Supergroup, whose rocks outcrop in the Waterton region.

 

AGE

ROCK TYPE

COMMENTS

7

TERTIARY

Conglomerate

Unit 7 is found west of the Flathead fault if the Front Ranges in British Columbia. It is the youngest bedrock unit in the region and was deposited soon after the rise of the Rocky Mountains.

6

UPPER CRETACEOUS AND TERTIARY

Alternating soft sandstone and shale units

Unit 6 is found in the foothills along the eastern margin of the park. The rocks are flat lying or gently folded.

5

UPPER CRETACEOUS

Alternating hard and soft sandstone and shale units

Units 4 and 5 are characteristic of the Foothills. Unit 5 is generally softer than Unit 4 and forms low ridges in the outer, or eastern, foothills.

4

PENNSYLVANIAN-PERMIAN, TRIASSIC, JURASSIC AND LOWER CRETACEOUS

Moderately hard sandstone and siltstone units; thick shales

Unit 4 makes up the higher, more rugged ridges of the inner or western foothills. The rocks are intensely folded and faulted, generally dipping steeply to the west. Thrust faults have caused the succession to be repeated several times within the Foothills belt.

3

PALEOZOIC ROCKS RANGING IN AGE FROM MIDDLE CAMBRIAN TO PERMIAN

Very hard limestones and dolomites; moderately hard shales

Units 1,2 and 3 make up the high mountains if the Front Ranges of the Rocky Mountains. They are thrust faulted over younger rocks along the major fracture lines such as the Lewis Thrust. Unit 3 outcrops near the summits and scattered peaks.

2

PRECAMBRIAN

Moderately hard argillites, dolomites, and igneous intrusives

Unit 2 is found primarily to the north and west of the park.

1

PRECAMBRIAN

Moderately hard limestones, dolomites, argillites and lavaflows

Unit 1 includes the oldest and most common rocks in the park. The greater resistance of those rocks, over those of the Foothills and Great Plains has caused the greater relief of the Front Ranges.

The rocks underlying the foothills consist of a series of fault slices overlapping and sloping to the west. Onto this mass of fault slices a series of older rocks has been brought up from the depths of the earth and laid on top the younger Rocks. The principle surface of this fault is known in Alberta and Montana as the Lewis Thrust.

 

These rocks have been transformed through the power of ice and water as well. A chronology of glacial activity has been documented for the last three or four advances. Stalker and Harrison(1977) suggest that the maximum ice advance occurred in the Illinoian, which they assign the name Waterton I with a date greater than 300,000 years BP. This is a diagram of advances in glaciation according to Stalker and Harrison.

  In an alpine environment, glacial erosion creates unique landforms including cirques, horns, hanging valleys, glacial troughs, truncated spurs, rock drumlins, roche mountonee, rock flutes and many more. Debris material eroded by the glacier is then transported glacially ( within the ice, on the surface, or in the meltwater flow). When the debris is dumped at the glacier margin, a moraine is formed. Waterton has excellent examples of glaciated landforms as shown in this aerial photo.

Here are some links that provide information about the geological and geomorphic studies of Waterton Lakes National Park.

Alberta Geography

Lewis Overthrust Fault (an excellent page that describes glacial landforms)

Landscape/Geology - Waterton

Canadian National Seismograph Network

Waterton Information - Geology

| Maps | Photos | Geology and Landforms | Biosphere Project | Natural Resources|

 |Wildlife and Vegetation | Climate | Human History | Tourism |

| Waterton-Glacier International Peace Park |

See also | Glacier National Park |

Back to Home

Send comments and mail to Karen Lindsay

 

Last updated by Karen Lindsay on 11/30/97