|
St. Mary River Formation
The St. Mary River Formation is a geologic Formation (geology), formation of Late Cretaceous (71.9-67 Mega-annum, Ma) Geochronology, age of the Western Canadian Sedimentary Basin, Western Canada Sedimentary Basin in southwestern Alberta and northwesternmost Montana. It was first described from outcrops along the St. Mary River (Alberta–Montana), St. Mary River by George Mercer Dawson in 1883, and it takes its name from the river. Fossils from the formation include remains of dinosaurs,Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press, pp. 574-588. . as well as bivalve shells, paleobotany, plant fossils, and trace fossils. Lithology The St. Mary River Formation is generally considered to consist of two units. The lower of the formation was deposited in brackish water environments, and is characterized ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve Shell
A bivalve shell is part of the body, the exoskeleton or shell, of a bivalve mollusk. In life, the shell of this class of mollusks is composed of two hinged parts or ''valves''. Bivalves are very common in essentially all aquatic locales, including saltwater, brackish water, and freshwater. The shells of bivalves commonly wash up on beaches (often as separate valves) and along the edges of lakes, rivers, and streams. Bivalves by definition possess two shells or ''valves'', a "right valve" and a "left valve", that are joined by a ligament. The two valves usually articulate with one another using structures known as "teeth" which are situated along the hinge line. In many bivalve shells, the two valves are symmetrical along the hinge line—when truly symmetrical, such an animal is said to be ''equivalved''; if the valves vary from each other in size or shape, ''inequivalved''. If symmetrical front-to-back, the valves are said to be ''equilateral'', and are otherwise considered ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conifer
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas-firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews.Campbell, Reece, "Phylum Coniferophyta". Biology. 7th. 2005. Print. P. 595 As of 1998, the division Pinophyta was estimated to contain eight families, 68 genera, and 629 living species. Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, but also in similar cool climates in mountains further south. Boreal conifers have many wintertime ada ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginkgo
''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus within the order. The rate of evolution within the genus has been slow, and almost all its species had become extinct by the end of the Pliocene. The sole surviving species, '' Ginkgo biloba'' is only found in the wild in China, but is cultivated around the world. The relationships between ginkgos and other groups of plants are not fully resolved. Prehistory The ginkgo (''Ginkgo biloba'') is a living fossil, with fossils similar to the modern plant dating back to the Permian, 270 million years ago. The closest living relatives of the clade are the cycads, which share with the extant ''G. biloba'' the characteristic of motile sperm. The ginkgo and cycad lineages are thought to have an extremely ancient divergence dating to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except the lycopods, and differ from mosses and other bryophytes by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate ( Polypodiidae) and eusporangiate ferns, the latter group including horsetails, whisk ferns, marattioid ferns, and ophioglossoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horseshoe Canyon Formation
The Horseshoe Canyon Formation is a stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. It takes its name from Horseshoe Canyon, an area of badlands near Drumheller. The Horseshoe Canyon Formation is part of the Edmonton Group and is up to thick. It is of Late Cretaceous age, Campanian to early Maastrichtian stage (Edmontonian Land-Mammal Age), and is composed of mudstone, sandstone, carbonaceous shales, and coal seams. A variety of depositional environments are represented in the succession, including floodplains, estuarine 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, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Bow River
The Little Bow River is a tributary of the Oldman River in southern Alberta, Canada. It is about long. From its headwaters near High River, it flows south, then turns east and flows into Travers Reservoir. Afterwards, it flows southeast into the Oldman River near Picture Butte. The Little Bow is related to the Bow River as they both ultimately feed the South Saskatchewan River. Water is diverted from the Highwood River and Bow River into the Little Bow as part of the Little Bow Project to facilitate irrigation practices in the surrounding plain. See also *Little Bow Provincial Park *List of rivers of Alberta Rivers of Alberta {{Alberta-river-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacier County, Montana
Glacier County is located in the U.S. state of Montana. As of the 2020 census, the population was 13,778. The county is located in northwestern Montana between the Great Plains and the Rocky Mountains, known to the Blackfeet as the "Backbone of the World". The county is geographically and culturally diverse and includes the Blackfeet Indian Reservation, Glacier National Park, and Lewis and Clark National Forest. The county is bordered by 75 miles of international boundary with two ports of entry ( Piegan and Del Bonita) open year-round and one seasonal (Chief Mountain) international border crossing into Alberta, Canada. Settlements Several small unincorporated communities, one incorporated town, and one incorporated city are located within the county. Cut Bank, the county seat with a population of around 3000, is located in eastern Glacier County, on the edge of the Great Plains. Cut Bank arose from the railroad and agriculture needs of the surrounding area, and was fostere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, and on to Grassy Lake, where it joins the Bow River to form the South Saskatchewan River, which eventually drains into the Hudson Bay. Oldman River has a total length of and a drainage area of . History The Oldman River was, at one time, known as the Belly River. The Belly River is now a separate river that is a tributary of the Oldman. In 1991, the Alberta government finished construction of the Oldman River Dam. The Piikani renegade, led by Milton Born With A Tooth, had attempted to divert the Oldman River away from the Lethbridge Northern Irrigation District canal intake, leading to an armed standoff. The dam was constructed where the Oldman, Crowsnest, and Castle river systems converge. 2013 floods On June 21, 2013, during the 2013 Alberta floods Alberta experienced heavy rainfall that triggered catastrophic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crowsnest River
The Crowsnest River is a tributary to the Oldman River in southwestern Alberta, Canada. Location From its source in Crowsnest Lake at an elevation of about in the Canadian Rockies, Crowsnest River meanders eastward through the Municipality of Crowsnest Pass and Frank Slide. It passes into the foothills near Burmis and reaches the western margin of the Alberta plains near Lundbreck. It then joins the Oldman River Reservoir at an elevation of about .Canada NTS Maps 82G/9 Blairmore and 82G/10 Crowsnest, 1:50:000 Fish species The Crowsnest River is highly productive with a substantial insect population fueling a world-class sport fishery for rainbow, westslope cutthroat, bull, hybrid trout ("cutbow" cutthroat and rainbow trout crosses), brown trout (below Lundbreck Falls), mountain whitefish, and various species of suckers. See also * List of rivers of Alberta Alberta's rivers flow towards three different bodies of water, the Arctic Ocean, the Hudson Bay and the Gulf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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.'' New York, New York, W. H. Freeman, 2nd ed, 529 pp. The term ''mudstone'' is also used to describe carbonate rocks (limestone or dolomite) that are composed predominantly of carbonate mud. However, in most contexts, the term refers to siliciclastic mudstone, composed mostly of silicate minerals. The NASA Curiosity rover has found deposits of mudstone on Mars that contain organic substances such as propane, benzene and toluene. Definition There is not a single definition of mudstone that has gained general acceptance,Boggs 2006, p.143 though there is wide agreement that mudstones are fine-grained sedimentary rocks, composed mostly of silicate grains with a grain size less than . Individual grains this size are too small to be distingui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coquina
Coquina () is a sedimentary rock that is composed either wholly or almost entirely of the transported, abraded, and mechanically sorted fragments of the shells of mollusks, trilobites, brachiopods, or other invertebrates. The term ''coquina'' comes from the Spanish word for " cockle" and "shellfish". For a sediment to be considered to be a coquina, the particles composing it should average or greater in size. Coquina can vary in hardness from poorly to moderately cemented. Incompletely consolidated and poorly cemented coquinas are considered grainstones in the Dunham classification system for carbonate sedimentary rocks. A well-cemented coquina is classified as a biosparite (fossiliferous limestone) according to the Folk classification of sedimentary rocks. Coquinas accumulate in high-energy marine and lacustrine environments where currents and waves result in the vigorous winnowing, abrasion, fracturing, and sorting of the shells that compose them. As a result, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
