The Horseshoe Canyon Formation is a stratigraphic unit of the

Western Canada Sedimentary Basin The Western Canadian Sedimentary Basin (WCSB) underlies of Western Canada including southwestern Manitoba, southern Saskatchewan, Alberta, northeastern British Columbia and the southwest corner of the Northwest Territories. This vast sedimen ...

in southwestern

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest T ...

. It takes its name from Horseshoe Canyon, an area of badlands near Drumheller. The Horseshoe Canyon Formation is part of the

Edmonton Group Within the earth science of geology, the Edmonton Group is a Late Cretaceous (Campanian stage) to early Paleocene stratigraphic unit of the Western Canada Sedimentary Basin in the central Alberta plains. It was first described as the Edmonton ...

and is up to thick. It is of Late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

age,

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campani ...

to early

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the inte ...

stage (Edmontonian

Land-Mammal Age In paleontology, biochronology is the correlation in time of biological events using fossils. In its strict sense, it refers to the use of assemblages of fossils that are not tied to stratigraphic sections (in contrast to biostratigraphy, where ...

), and is composed of

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology.' ...

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicat ...

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon ma ...

aceous

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especiall ...

s, and

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...

seams. A variety of depositional environments are represented in the succession, including

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...

channels, and coal swamps, which have yielded a diversity of fossil material. Tidally-influenced estuarine point bar deposits are easily recognizable as Inclined Heterolithic Stratification (IHS). Brackish-water trace fossil assemblages occur within these bar deposits and demonstrate periodic incursion of marine waters into the estuaries. The Horseshoe Canyon Formation crops out extensively in the area around Drumheller, as well as farther north along the

Red Deer River The Red Deer River is a river in Alberta and a small portion of Saskatchewan, Canada. It is a major tributary of the South Saskatchewan River and is part of the larger Saskatchewan-Nelson system that empties into Hudson Bay. Red Deer River h ...

near Trochu and along the North Saskatchewan River in

Edmonton Edmonton ( ) is the capital city of the Canadian province of Alberta. Edmonton is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Alberta's central region. The city an ...

. It is overlain by the Battle, Whitemud, and Scollard formations. The Drumheller Coal Zone, located in the lower part of the Horseshoe Canyon Formation, was mined for sub-bituminous coal in the Drumheller area from 1911 to 1979, and the Atlas Coal Mine in Drumheller has been preserved as a National Historic Site. In more recent times, the Horseshoe Canyon Formation has become a major target for

coalbed methane Coalbed methane (CBM or coal-bed methane), coalbed gas, coal seam gas (CSG), or coal-mine methane (CMM) is a form of natural gas extracted from coal beds. In recent decades it has become an important source of energy in United States, Canada, Au ...

(CBM) production. Bearpaw-Horseshoe Canyon

Dinosaurs found in the Horseshoe Canyon Formation include '' Albertavenator'', '' Albertosaurus'', ''

Anchiceratops ''Anchiceratops'' ( ) is an extinct genus of chasmosaurine ceratopsid dinosaur that lived approximately 72 to 71 million years ago during the latter part of the Cretaceous Period in what is now Alberta, Canada. ''Anchiceratops'' was a medium-siz ...

'', '' Anodontosaurus'', '' Arrhinoceratops'', ''

Atrociraptor ''Atrociraptor'' (meaning "savage thief") is a genus of saurornitholestine dromaeosaurid theropod dinosaur from the Late Cretaceous (Maastrichtian stage) of Alberta, Canada. The type (and only) specimen of ''Atrociraptor'', holotype RTMP 95 ...

'', ''

Epichirostenotes ''Epichirostenotes'' (meaning "above ''Chirostenotes''", because it lived after the latter genus) is a genus of oviraptorosaurian dinosaur from the late Cretaceous. ''Epichirostenotes'' is known from an incomplete skeleton found in 1923 at the H ...

'', '' Edmontonia'', ''

Edmontosaurus ''Edmontosaurus'' ( ) (meaning "lizard from Edmonton") is a genus of hadrosaurid (duck-billed) dinosaur. It contains two known species: ''Edmontosaurus regalis'' and '' Edmontosaurus annectens''. Fossils of ''E. regalis'' have been found in rock ...

'', '' Hypacrosaurus'', '' Ornithomimus'', '' Pachyrhinosaurus'', '' Parksosaurus'', ''

Saurolophus ''Saurolophus'' (; meaning "lizard crest") is a genus of large hadrosaurid dinosaur from the Late Cretaceous period of Asia and North America, that lived in what is now the Horseshoe Canyon and Nemegt formations about 70 million to 68 million ...

'', and '' Struthiomimus''. Other finds have included

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...

s such as '' Didelphodon coyi'', non-dinosaur

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...

amphibian Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbo ...

fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...

, marine and terrestrial

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...

s and plant fossils. Reptiles such as turtles and crocodilians are rare in the Horseshoe Canyon Formation, and this was thought to reflect the relatively cool climate which prevailed at the time. A study by Quinney et al. (2013) however, showed that the decline in turtle diversity, which was previously attributed to climate, coincided instead with changes in soil drainage conditions, and was limited by aridity, landscape instability, and migratory barriers.

Oil/gas production

The Drumheller Coal Zone has been a primary coalbed methane target for industry. In the area between Bashaw and Rockyford, the Coal Zone lies at relatively shallow depths (about 300 metres) and is about 70 to 120 metres thick. It contains 10 to 20 metres of cumulative coal, in up to 20 or more individual thin seams interbedded with sandstone and shale, which combine to make an attractive multi-completion CBM drilling target. In total, it is estimated there are 14 trillion cubic metres (500 tcf) of gas in place in all the coal in Alberta.

Biostratigraphy

The timeline below follows work by David A. Eberth and Sandra L. Kamo published in 2019.
ImageSize = width:1000px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-73.2 till:-67.2 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:1 start:-73.2 ScaleMinor = unit:year increment:1 start:-73.2 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:cretaceous value:rgb(0.675,0.675,0.35) id:jurassic value:rgb(0.753,0.753,0.486) id:triassic value:rgb(0.827,0.827,0.65) id:mesozoic value:rgb(0.54,0.54,0.258) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:NAM3 bar:NAM4 bar:NAM5 bar:NAM6 bar:NAM7 bar:NAM8 bar:NAM9 bar:NAM10 bar:NAM11 bar:NAM12 bar:NAM13 bar:NAM14 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -68.0 till: -67.2 color:triassic text:- from: -73.2 till: -68.0 color:jurassic text:Horseshoe Canyon Formation bar:eratop from: -72.1 till: -67.2 color:mesozoic text:Maastrichtian from: -73.2 till: -72.1 color:cretaceous text:Campanian PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:HER bar:NAM1 from:-72.7 till:-71.9 text: Pachyrhinosaurus canadensis color:CAR bar:NAM2 from:-72.6 till:-70.9 text: Struthiomimus sp. color:CAR bar:NAM3 from:-72.5 till:-69.6 text:

Ornithomimus edmontonicus ''Ornithomimus'' (; "bird mimic") is a genus of ornithomimid dinosaurs from the Late Cretaceous Period of what is now North America. ''Ornithomimus'' was a swift bipedal theropod which fossil evidence indicates was covered in feathers, equipped ...

color:ANK bar:NAM4 from:-72.2 till:-70.8 text: Anodontosaurus lambei color:HER bar:NAM5 from:-72.6 till:-70.3 text:

Anchiceratops ornatus ''Anchiceratops'' ( ) is an extinct genus of chasmosaurine ceratopsid dinosaur that lived approximately 72 to 71 million years ago during the latter part of the Cretaceous Period in what is now Alberta, Canada. ''Anchiceratops'' was a medium-size ...

color:HAD bar:NAM6 from:-73.0 till:-71.5 text:

Edmontosaurus regalis ''Edmontosaurus regalis'' is a species of comb-crested hadrosaurid (duck-billed) dinosaur. Fossils of ''E. regalis'' have been found in rocks of western North America that date from the late Campanian stage of the Cretaceous Period 73 million yea ...

color:CAR bar:NAM7 from:-73.0 till:-69.6 text: Albertosaurus sarcophagus color:ANK bar:NAM8 from:-71.8 till:-71.5 text:

Edmontonia longiceps ''Edmontonia'' is a genus of panoplosaurin nodosaurid dinosaur from the Late Cretaceous Period. It is part of the Nodosauridae, a family within Ankylosauria. It is named after the Edmonton Formation (now the Horseshoe Canyon Formation in Canada ...

color:HER bar:NAM9 from:-72.3 till:-70.5 text: Arrhinoceratops brachyops color:HAD bar:NAM10 from:-71.5 till:-69.6 text:

Hypacrosaurus altispinus ''Hypacrosaurus'' (meaning "near the highest lizard" reek υπο-, ''hypo-'' = less + ακρος, ''akros'', high because it was almost but not quite as large as ''Tyrannosaurus'') was a genus of duckbill dinosaur similar in appearance to ''Co ...

color:HAD bar:NAM11 from:-70.9 till:-69.6 text:

Saurolophus osborni ''Saurolophus'' (; meaning "lizard crest") is a genus of large hadrosaurid dinosaur from the Late Cretaceous period of Asia and North America, that lived in what is now the Horseshoe Canyon and Nemegt formations about 70 million to 68 million ...

color:HER bar:NAM12 from:-70.8 till:-70.5 text:

Sphaerotholus edmontonense ''Sphaerotholus'' is a genus of pachycephalosaurid dinosaur from the Upper Cretaceous of the western United States and Canada. To date, three species have been described: the type species, ''S. goodwini'', from the Den-na-zin Member of the Kirt ...

color:HER bar:NAM13 from:-70.9 till:-69.8 text:

Parksosaurus warreni ''Parksosaurus'' (meaning " William Parks's lizard") is a genus of neornithischian dinosaur from the early Maastrichtian-age Upper Cretaceous Horseshoe Canyon Formation of Alberta, Canada. It is based on most of a partially articulated skeleton ...

color:HER bar:NAM14 from:-68.9 till:-68.6 text: Eotriceratops xerinsularis PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -68.0 till: -67.2 color:triassic text:- from: -68.2 till: -68.0 color:jurassic text:Whitemud M. from: -69.6 till: -68.2 color:triassic text:Carbon M. from: -70.9 till: -69.6 color:jurassic text:Tolman M. from: -71.5 till: -70.9 color:triassic text:Morrin M. from: -72.3 till: -71.5 color:jurassic text:Horsethief M. from: -73.2 till: -72.3 color:triassic text:Drumheller M. bar:era from: -72.1 till: -67.2 color:mesozoic text:Maastrichtian from: -73.2 till: -72.1 color:cretaceous text:Campanian

Dinosaurs

Ankylosaurs

Maniraptors

Marginocephalians

Ornithomimids

Hadrosaurs and thescelosaurs

Tyrannosaurs

Other Animals

Mammals

Other Reptiles

Fish

References

Bibliography

* Makovicky, P. J., 2001, A ''Montanoceratops cerorhynchus'' (Dinosauria: Ceratopsia) braincase from the Horseshoe Canyon Formation of Alberta: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 243–262. * Varricchio, D. J. 2001. Late Cretaceous oviraptorosaur (Theropoda) dinosaurs from Montana. pp. 42–57 in D. H. Tanke and K. Carpenter (eds.), Mesozoic Vertebrate Life. Indiana University Press, Indianapolis, Indiana. * Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. . {{Authority control Geologic formations of Alberta Cretaceous Alberta Maastrichtian Stage of North America Upper Cretaceous Series of North America Sandstone formations Shale formations Coal formations Fluvial deposits Tidal deposits Reservoir rock formations Source rock formations Western Canadian Sedimentary Basin Fossiliferous stratigraphic units of North America Paleontology in Alberta