The Ravenscrag 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 Late Cretaceous

Late Cretaceous

The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...

 to Tertiary

Tertiary

The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...

 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...

.

It takes the name from the settlement of Ravenscrag, Saskatchewan, and was first described in outcrop at Ravenscrag Butte near 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....

 by N.B. Davis in 1918.

Lithology

The Ravenscrag Formation is composed of arenaceous claystone

Claystone

Claystone is a geological term used to describe a clastic sedimentary rock that is composed primarily of clay-sized particles ....

, with sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 and coal

Coal

Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

 interbeds.

Distribution

The Ravenscrag Formation reaches a maximum thickness of 244 metres (800.5 ft) and is present as the erosional surface in south-western 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....

 and in the Cypress Hills area.

Relationship to other units

The Ravenscrag Formation is conformably overlain by the Swift Current Formation where not eroded and conformably overlays the Frenchman Formation

Frenchman Formation

The Frenchman Formation is a division of Upper Cretaceous rocks found in Saskatchewan, Canada. More accurately described as Late Maastrichtian, these rocks contain the youngest of dinosaur genera, much like the Hell Creek Formation in the United States....

 or separated by an erosion

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

al surface from the underlying Battle Formation, Whitemud Formation, Eastend Formation

Eastend Formation

The Eastend Formation is a stratigraphical unit of Maastrichtian age in the Western Canadian Sedimentary Basin.It takes the name from the town of Eastend, and was first described in outcrop around the settlement by L.S. Russell in 1932. The type locality was later defined south-west of the town by...

 or Bearpaw Formation

Bearpaw Formation

The Bearpaw Formation, also called the Bearpaw Shale, is a sedimentary rock formation found in northwestern North America. It is exposed in the U.S. state of Montana, as well as the Canadian provinces of Alberta and Saskatchewan, east of the Rocky Mountains...

.

It is equivalent to the Lance Formation

Lance Formation

The Lance Formation is a division of Late Cretaceous rocks in the western United States. Named after Lance Creek, Wyoming, the microvertebrate fossils and dinosaurs represent important components of the latest Mesozoic vertebrate faunas...

 in Montana

Montana

Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

, the Brazeau Formation of the foothills of 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...

 and the Paskapoo Formation

Paskapoo Formation

The Paskapoo Formation is a stratigraphical unit of Paleocene age in the Western Canadian Sedimentary Basin.It takes the name from the Blindman River , and was first described in outcrops along the river, north of Red Deer by J. B...

 in southern Alberta

Southern Alberta

Southern Alberta is a region located in the Canadian province of Alberta. As of the year 2004, the region's population was approximately 272,017. The primary cities are Lethbridge and Medicine Hat...

.