The Dirt Hills | |
---|---|
Highest point | |
Elevation | 880 m (2,890 ft) |
Coordinates | 49°59′39″N 105°11′18″W / 49.99417°N 105.18833°W |
Geography | |
Location | Missouri Coteau, Saskatchewan, Canada |
The Dirt Hills[1] and neighbouring Cactus Hills,[2] are an arcuate moraine and the largest glacial push in the world. The hills were formed during the deglaciation of the last ice age over 10,000 years ago. They are located in the southern region of the Canadian province of Saskatchewan, east of Old Wives Lake and about 60 kilometres (37 mi) south-east of Moose Jaw and are part of the Bearpaw Formation within Palliser's Triangle and the Great Plains ecoregion.[3]
As the last ice age was ending, there was a lot of glacial movement and the compressive flow of the ice sheet forced the glaciers to re-advance up the Missouri Coteau escarpment. The advancing ice sheet acted like a bulldozer pushing, moving, and uplifting earth until in ran into the upward slope of the escarpment. The Dirt Hills are composed mostly of bedrock and drift that was stacked up to form a single block 215 metres (705 ft) thick where the ice sheet ended its advance.[4]
The moraine has an area of almost 1,000 square kilometres (390 sq mi) with a height of 880 metres (2,890 ft) above sea level. The Dirt and Cactus Hills form an amphitheatre-shaped landform. The north-western side of the amphitheatre-shaped moraine is called the Cactus Hills and the eastern and southern portion is The Dirt Hills. During the deglaciation of that last ice age, there was a glacial sub-lobe, also known as a tongue, between the hills named Spring Valley ice tongue. It is named after the community of Spring Valley that sits at the head of where the ice tongue was. The Dirt Hills are 7.5 kilometres (4.7 mi) wide, 40 kilometres (25 mi) long, and rise 120 metres (390 ft) above the surrounding prairie. They stretch from Claybank in the east to Galilee in the west. The Cactus Hills rise to a height of 737 metres (2,418 ft) above sea level.[5]