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A push moraine or pushed moraine is in
geomorphology Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or n ...
a
moraine A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...
(a
landform A landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, ...
formed by
glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betw ...
processes) that forms when the terminus advance of a lowland glacier pushes unstratified glacial sediment into a pile or linear ridge in front of it. A push moraine is identified by its ability to push sediment upwards from its original horizontal position. Push moraines are limited in size by the advance of a glacier front and its tendency to shear over the top of any ridge large enough to resist the movement of ice. Pushed moraines generally occur in low, flat plains at higher
latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...
s and were formed during the
glacial stage An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...
s of the
Quaternary ice age The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million year ...
. They can be up to 100 km long and several hundreds of metres in height. Pushed moraines can be found in the North American plains, in
Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
and in Northern Europe. They were formed during cool, glacial stages, when glaciers advanced and covered large parts of North America and Eurasia. In some regions pushed moraines of more than one glacial stage can be recognised, or different generations from a single glacial phase. Since new glacial advances tend to destroy older pushed moraines, most were formed during the last (110,000 to 10,000 years ago) or second-last (238,000 to 128,000 years ago) glacial advances. Today push moraines can be found anywhere an advancing glacier is pushing sediment into a ridge at the terminus. The largest push moraine in the world is the Dirt Hills in southern
Saskatchewan Saskatchewan ( ; ) is a Provinces and territories of Canada, province in Western Canada, western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on t ...
,
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
. The hills are located about 60 kilometres south-east of city of
Moose Jaw Moose Jaw is the fourth largest city in Saskatchewan, Canada. Lying on the Moose Jaw River in the south-central part of the province, it is situated on the Trans-Canada Highway, west of Regina. Residents of Moose Jaw are known as Moose Javians ...
, along the
Missouri Coteau The Missouri Coteau, or Missouri Plateau, (french: Coteau du Missouri) is a large plateau that stretches along the eastern side of the valley of the Missouri River in central North Dakota and north-central South Dakota in the United States. In t ...
.


See also

*
Terminal moraine A terminal moraine, also called end moraine, is a type of moraine that forms at the terminal (edge) of a glacier, marking its maximum advance. At this point, debris that has accumulated by plucking and abrasion, has been pushed by the front edge ...


References

Moraines Glaciology {{glaciology-stub