The Cypress Hills Formation is a stratigraphical

Stratigraphy

Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....

 unit of Oligocene

Oligocene

The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

 age

Geochronology

Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...

 in the Western Canadian Sedimentary Basin

Western Canadian Sedimentary Basin

The Western Canadian Sedimentary Basin is a vast sedimentary basin underlying of Western Canada including southwestern Manitoba, southern Saskatchewan, Alberta, northeastern British Columbia and the southwest corner of the Northwest Territories. It consists of a massive wedge of sedimentary rock...

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It takes the name from the Cypress Hills, and was first described in outcrops on the slopes of the Cypress Hills by M.Y. Williams and W.S. Dyer in 1930. Type localities are found at Anxiety Butte in south-western Saskatchewan, as well as hill slopes in south-eastern Alberta

Alberta

Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...

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Lithology

The Cypress Hills Formation is composed of loose quartz

Quartz

Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

itic gravel

Gravel

Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

 and sand

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

, occasionally conglomerate

Conglomerate (geology)

A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...

 and marl

Marl

Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and aragonite. Marl was originally an old term loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay...

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Distribution

The Cypress Hills Formation reaches a maximum thickness of 80 metres (262.5 ft) in the sub-surface in Saskatchewan, and is typically 40 metres (131.2 ft) thick. It occurs in the elevated Cypress hills, as well as in several plateau remnants in south-eastern Saskatchewan, south of the Frenchman River

Frenchman River

Frenchman River, or Frenchman Creek, is a river in Saskatchewan, Canada and Montana, United States. It is a tributary of the Milk River, itself a tributary of the Missouri.The river is approximately long....

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Relationship to other units

The Cypress Hills Formation forms the present day erosional surface, or may be covered by Laurentian Drift and loess

Loess

Loess is an aeolian sediment formed by the accumulation of wind-blown silt, typically in the 20–50 micrometre size range, twenty percent or less clay and the balance equal parts sand and silt that are loosely cemented by calcium carbonate...

. It conformably overlays the Ravenscrag Formation

Ravenscrag Formation

The Ravenscrag Formation is a stratigraphical unit of Late Cretaceous to Tertiary age in the Western Canadian Sedimentary Basin.It takes the name from the settlement of Ravenscrag, Saskatchewan, and was first described in outcrop at Ravenscrag Butte near Frenchman River by N.B...

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It is equivalent to the Swift Current Creek Formation in southern Saskatchewan

Saskatchewan

Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....

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