The Belly River 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...

 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 Belly River

Belly River

Belly River is a river in northwest Montana, United States and southern Alberta, Canada. It is a tributary of the Oldman River, itself a tributary of the South Saskatchewan River....

, a tributary of the Oldman River

Oldman River

The Oldman River is a river in southern Alberta, Canada. It flows roughly west to east from the Rocky Mountains, through the communities of Fort Macleod, Lethbridge, Taber, and on to Grassy Lake, where it joins with the Bow River to form the South Saskatchewan River, which eventually drains into...

 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...

, and was first described in outcrop on the banks of the Oldman River

Oldman River

The Oldman River is a river in southern Alberta, Canada. It flows roughly west to east from the Rocky Mountains, through the communities of Fort Macleod, Lethbridge, Taber, and on to Grassy Lake, where it joins with the Bow River to form the South Saskatchewan River, which eventually drains into...

 (at the time considered part of the Belly River) and Bow River

Bow River

The Bow River is a river in the Canadian province of Alberta. It is a tributary of the South Saskatchewan River, and is considered the headwater of the Nelson River....

 by George Mercer Dawson

George Mercer Dawson

Dr. George Mercer Dawson F.R.S., C.M.G., was a Canadian scientist and surveyor. He was born in Pictou, Nova Scotia, the eldest son of Sir John William Dawson, Principal of McGill University and his wife, Lady Margaret Dawson...

 in 1883.

Lithology

The Belly River Formation is composed of very fine grained 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,...

 with coarse grained beds and minor bentonite

Bentonite

Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...

, 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...

, green shale

Shale

Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...

 and concretionary beds.

Hydrocarbon production

Gas

Natural gas

Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 is produced from the Belly River Formation in the Deep Basin, in west-central Alberta

Central Alberta

Central Alberta is a region located in the Canadian province of Alberta.Central Alberta is the most densely populated rural area in the province...

 and in the Canadian Rockies

Canadian Rockies

The Canadian Rockies comprise the Canadian segment of the North American Rocky Mountains range. They are the eastern part of the Canadian Cordillera, extending from the Interior Plains of Alberta to the Rocky Mountain Trench of British Columbia. The southern end borders Idaho and Montana of the USA...

 foothills.

Paleofauna

Dinosaur remains are among the fossils that have been recovered from the formation.

Dinosaur Dinosaur Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of... s reported from the Kanguk Formation
Genus	Species	Location	Stratigraphic position	Material	Description	Images
Montanoceratops Montanoceratops Montanoceratops was a genus of small ceratopsian dinosaur. It lived during the early Maastrichtian of the late Cretaceous Period...	Indeterminate

Distribution

The Belly River Formation reaches a maximum thickness of 1300 metres (4,265.1 ft) in its western reaches, and thins out eastward to about 350 metres (1,148.3 ft) in the Canadian Plains. It is found throughout 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...

, and as far east as eastern 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....

. From south to north, it is present from the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 border to the Wapiti River

Wapiti River

Wapiti River is a river in eastern British Columbia and western Alberta, Canada. It is a major tributary of the Smoky River, located in the southern area of the Peace River Basin.Wapiti is named after the Cree word for elk .-Course:...

 region, south of the Peace River Country

Peace River Country

The Peace River Country is an aspen parkland region around the Peace River in Canada. It spans from northwestern Alberta to the Rocky Mountains in northeastern British Columbia, where the region is also referred to as the Peace River Block.- Geography :The Peace River Country includes the...

.

Relationship to other units

The Belly River Formation is conformably overlain by the 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...

 and gradually overlies the Wapiabi Formation, the Colorado Group

Colorado Group

The Colorado Group, also called the Colorado shale, is a stratigraphical unit of Cretaceous age in the Western Canadian Sedimentary Basin.It was first described in the Rocky Mountains front ranges of Colorado by A. Hague and S.E...

 shale or the Lea Park Formation

Lea Park Formation

The Lea Park Formation is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin, Canada.It takes the name from the settlement of Lea Park, Alberta, located north-west of Lloydminster on the banks of the North Saskatchewan River. It was first defined in an outcrop...

 shale.

It is equivalent to the Milk River Formation

Milk River Formation

The Milk River Formation is a near- shore to terrestrial sedimentary unit deposited during the Late Cretaceous in southern Alberta...

 and Pakowki Formation

Pakowki Formation

The Pakowki Formation is a stratigraphical unit of Campanian age in the Western Canadian Sedimentary Basin.It takes the name from Pakowki Lake, and was first described in outcrop along the Pakowki Coulee by D.B. Dowling in 1916.-Lithology:...

. The Belly River has group status in the Canadian Rockies

Canadian Rockies

The Canadian Rockies comprise the Canadian segment of the North American Rocky Mountains range. They are the eastern part of the Canadian Cordillera, extending from the Interior Plains of Alberta to the Rocky Mountain Trench of British Columbia. The southern end borders Idaho and Montana of the USA...

 foothills and is replaced by the Judith River Formation

Judith River Formation

The Judith River Formation is a fossil-bearing geologic formation in Montana, and is part of the Judith River Group. It dates to the upper Cretaceous, between 80 and 75 million years ago, corresponding to the "Judithian" land vertebrate age...

, Oldman Formation

Oldman Formation

The Oldman Formation is the middle member of the Judith River Group, a major geologic unit in southern Alberta. The formation is widely recognized as bearing a great number of well preserved dinosaur skeletons, as well as other fossils.-Age:...

 and Foremost Formation

Foremost Formation

The Foremost Formation is a geological formation in Alberta, Canada whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Dinosaurs:...

 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...

.