Red Rock Coulee is a Provincial Natural Area in southeastern

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, south-southwest of the city of

Medicine Hat Medicine Hat is a city in Southern Alberta, southeast Alberta, Canada. It is located along the South Saskatchewan River. It is approximately east of Lethbridge and southeast of Calgary. This city and the adjacent Town of Redcliff, Alberta, R ...

and south of the hamlet of Seven Persons on Alberta Highway 887. The main feature of this

natural landscape A natural landscape is the original landscape that exists before it is acted upon by human culture. The natural landscape and the cultural landscape are separate parts of the landscape. However, in the 21st century, landscapes that are totally ...

is the large spherical reddish boulders (

concretions A concretion is a hard and compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes a ...

), some of which measure in diameter. They are scattered across the

badlands Badlands are a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded."Badlands" in '' Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 2, p. 47. They are characterized by steep slopes, ...

and

coulee Coulee, or coulée ( or ), is any of various different landforms, all of which are kinds of valleys or drainage zones. The word ''coulee'' comes from the Canadian French ''coulée'', from French ''couler'' 'to flow'. The term is often used ...

s, and can be seen along the

hiking A hike is a long, vigorous walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century. Long hikes as part of a religious pilgrimage have existed for a much longer time. "Hi ...

trails, as well as from the viewpoint on Highway 887.

Geologic setting

Sweetgrass Hills in Montana from Red Rock Coulee

The large spherical

concretion A concretion is a hard and compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes a ...

s at Red Rocks Coulee are hosted in the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

(

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. Campa ...

)

Bearpaw Formation The Bearpaw Formation, also called the Bearpaw Shale, is a geologic formation of Late Cretaceous (Campanian) age. It outcrops in the U.S. state of Montana, as well as the Canadian provinces of Alberta and Saskatchewan, and was named for the Bear ...

, which makes up the

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of bed ...

in the area. The formation lies close to surface under a thin layer of soil, and it has been sculpted by

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

, exposing the concretions and creating areas of

and hoodoos. The dark gray

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

, with

beds A bed is a piece of furniture that is used as a place to sleep, rest, and relax. Most modern beds consist of a soft, cushioned mattress on a bed frame. The mattress rests either on a solid base, often wood slats, or a sprung base. Many be ...

of greenish and gray

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility. Although its permeabil ...

, pale grey

bentonite Bentonite ( ) is an Absorption (chemistry), absorbent swelling clay consisting mostly of montmorillonite (a type of smectite) which can either be Na-montmorillonite or Ca-montmorillonite. Na-montmorillonite has a considerably greater swelli ...

, and brown

ironstone Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron ore compound from which iron (Fe) can be smelted commercially. Not to be c ...

in the bedrock create bands of color across the exposed badlands. The Bearpaw Formation was deposited in the

Western Interior Seaway The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, or the Western Interior Sea) was a large inland sea (geology), inland sea that existed roughly over the present-day Great Plains of ...

and it includes a variety of marine

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s, primarily remains of

ammonite Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

, and

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

. The concretions formed after the sediments had been deposited, when mineral cement, primarily

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

and ironstone,

precipitated In an aqueous solution, precipitation is the "sedimentation of a solid material (a precipitate) from a liquid solution". The solid formed is called the precipitate. In case of an inorganic chemical reaction leading to precipitation, the chemic ...

around bits of shell, bone, and other biological debris.Tsujita, Cameron J. 1995. Stratigraphy, taphonomy, and paleoecology of the Upper Cretaceous Bearpaw Formation in southern Alberta, p. 131-138. Unpublished Ph.D. thesis, McMaster University, Hamilton, Ontario, 357 p. The concretions grew outward as circulating waters deposited more layers of cement. The cement makes the concretions resistant to erosion compared to the surrounding sediments, and the iron minerals give them their reddish color. Close examination of the concretions may reveal traces of the original bedding and other

sedimentary structures Sedimentary structures include all kinds of features in sediments and sedimentary rocks, formed at the time of deposition. Sediments and sedimentary rocks are characterized by bedding, which occurs when layers of sediment, with different parti ...

. There may also be "growth rings" produced by the layers of cement, as well as remnants of the fossils that were the nucleus for cementation.Benham, P., Froestad, B. and Miller, T. 2019. Hike 24, Red Rock Coulee; In: Benham, P. McKenzie, B., Chatellier, J.Y., and Tippet, C. (editors); Go Take A Hike, the Geology of Trails in the Canadian Rockies and Surrounding Areas, p. 96-99. Canadian Society of Petroleum Geologists, 284 p. .

Flora and fauna

Red Rock Coulee sits within

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

s of the mixed grass and dry mixed grass type.

Sagebrush Sagebrush is the common name of several woody and herbaceous species of plants in the genus ''Artemisia (plant), Artemisia''. The best-known sagebrush is the shrub ''Artemisia tridentata''. Sagebrush is native to the western half of North Amer ...

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' ( ) of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere as far south ...

shrubs, and

prickly pear cactus ''Opuntia'', commonly called the prickly pear cactus, is a genus of flowering plants in the cactus family Cactaceae, many known for their flavorful fruit and showy flowers. Cacti are native to the Americas, and are well adapted to arid climat ...

grow on the coulee walls, and on the uplands there are colorful wildflowers such as

prairie crocus ''Pulsatilla nuttalliana'', known as American pasqueflower, prairie pasqueflower, prairie crocus, or simply pasqueflower, is a flowering plant native to much of North America, from the western side of Lake Michigan, to northern Canada in the Nort ...

, gumbo evening primrose, yellow umbrella plant, and broomweed. Animals that are adapted to the harsh, dry conditions at the coulee include

white-tailed jackrabbit The white-tailed jackrabbit (''Lepus townsendii''), also known as the prairie hare and the white jack, is a species of hare found in western North America. Like all hares and rabbits, it is a member of the family Leporidae of order Lagomorpha. I ...

mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whit ...

pronghorn The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American ante ...

Richardson's ground squirrel Richardson's ground squirrel (''Urocitellus richardsonii''), also known as the dakrat or flickertail, is a North American ground squirrel in the genus ''Urocitellus''. Like a number of other ground squirrels, they are sometimes called prairie dog ...

, prairie rattlesnake, bullsnake, and

greater short-horned lizard The greater short-horned lizard (''Phrynosoma hernandesi)'', also commonly known as the mountain short-horned lizard or Hernández's short-horned lizard, is a species of lizard in the family Phrynosomatidae. The species is endemic to western Nor ...

. There are also northern scorpions, which are rare in Alberta. Birds sighted in the area include

prairie falcon The prairie falcon (''Falco mexicanus'') is a medium-sized Falconiformes, falcon found in Western North America. A separate species from the peregrine falcon, with which it shares some visual similarities, the prairie falcon is, essentially, an ...

western meadowlark The western meadowlark (''Sturnella neglecta'') is a medium-sized icterid bird, about in length. It is found across western and central North America and is a Bird migration, full migrant, breeding in Canada and the United States with resident ...

Sprague's pipit Sprague's pipit (''Anthus spragueii'') is a small songbird (passerine) in the family Motacillidae that breeds in the short- and mixed-grass prairies of North America. Migratory, it spends the winters in the southwestern United States and northern ...

longspur The longspurs, genus ''Calcarius'', are a group of birds in the family Calcariidae. The name refers to the long claw on the hind toe of each foot. The genus formerly included the thick-billed longspur, ''Rhyncophanes mccownii'', which is now pl ...

, and

rock wren The rock wren (''Salpinctes obsoletus'') is a small songbird of the wren family native to western North America, Mexico and Central America. It is the only species in the genus ''Salpinctes''. Description Measurements: * Length: 4.9-5.9 ...

Geologic setting

Flora and fauna

See also