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Stephen Formation
The Stephen Formation is a geologic formation exposed in the Canadian Rockies of British Columbia and Alberta, on the western edge of the Western Canada Sedimentary Basin. It consists of shale, thin-bedded limestone, and siltstone that was deposited during Middle Cambrian time (513 to 497 million years ago). It is famous for the exceptional preservation of soft-bodied fossils: the Burgess Shale biota. The formation overlies the Cathedral escarpment, a submarine cliff; consequently it is divided into two quite separate parts, the 'thin' sequence deposited in the shallower waters atop the escarpment, and the 'thick' sequence deposited in the deeper waters beyond the cliff. Because the 'thick' Stephen Formation represents a distinct lithofacies, some authors suggest it warrants its own name, and dub it the Burgess Shale Formation. The stratigraphy of the Thin Stephen Formation has not been subject to extensive study, so except where explicitly mentioned this article applies main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walcott Quarry
The Walcott Quarry is the most famous quarry of the Middle Cambrian Burgess Shale, located in the Canadian Rockies The Canadian Rockies () or Canadian Rocky Mountains, comprising both the Alberta Rockies and the British Columbian Rockies, is the Canadian segment of the North American Rocky Mountains. It is the easternmost part of the Canadian Cordillera, w ... of British Columbia, bearing the Phyllopod beds. This lies at the base of the Walcott Quarry member, on a ridge between Wapta Mountain and Mount Field, and three other quarries – the Raymond, UE and EZ – lie above it. The quarry's proximity to the Cathedral escarpment led to the preservation of spectacular fossils. History After locating soft-bodied fossils in loose fragments of rock in 1907, the Phyllopod bed was located as a source for the fragments' origins by the Walcotts in 1910. The Walcott quarry was opened the subsequent year, and extensive quarrying was performed in field seasons until 191 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers (Lamination (geology), laminae) less than one centimeter in thickness. This property is called ''Fissility (geology), fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the narrower sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odaray Mountain
Odaray Mountain is a summit located west of Lake O'Hara in the Bow Range of Yoho National Park, in the Canadian Rockies of British Columbia, Canada. Its nearest higher peak is Mount Huber, to the east. The standard climbing route follows the southeast glacier and ridge starting from Elizabeth Parker hut. Pronunciation sounds like the two words "ode array" (/ōd/ /əˈrā/). History The first ascent of the mountain was made in 1887 by James J. McArthur, and he named it ''Odaray'' which is the expression for "many waterfalls" in the Stoney language. Other reports have it being named in 1894 by Samuel Evans Stokes Allen for the Stoney Indian word for "cone". However, it is possible that McArthur only ascended the lesser secondary summit cone (2965 m) now known as ''Little Odaray'' which is southeast of the true summit. The mountain's current name became official in 1952 when the Geographical Names Board of Canada rescinded the name ''Mount Odaray''. Geology Odaray Mountain is c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Stephen Trilobite Beds
The Mount Stephen trilobite beds (UNSM locality 14s) are a series of fossil strata on Mount Stephen, British Columbia that contain exceptionally preserved fossil material. Part of the same stratigraphic unit as the Burgess Shale deposit, many non-mineralized parts (such as anomalocarid claws, sponges, and trilobite legs) are preserved; in addition, a high density of trilobite fossils is present. History The trilobite beds were the first Burgess shale locality to be discovered. The richness of fossils in the Field area was first identified by workers associated with the construction of the Trans-Canada railway, which had (somewhat controversially) been routed through the Kicking Horse valley. Richard McConnell, of the Geological Survey of Canada, was pointed to the beds by a railway worker whilst mapping the geology around the railway line in September 1886. Several unusual fossils were subsequently described from this site, including sponges, worms, and the appendages of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllopod Bed
The Phyllopod bed, designated by USNM locality number 35k, is the most famous fossil-bearing member of the Burgess Shale fossil ''Lagerstätte''. It was quarried by Charles Walcott from 1911–1917 (and later named Walcott Quarry), and was the source of 95% of the fossils he collected during this time; tens of thousands of soft-bodied fossils representing over 150 genera have been recovered from the Phyllopod bed alone. Stratigraphy and location The phyllopod bed is a 2.31 m thick layer of the 7 m thick Greater Phyllopod Bed, found in the Walcott Quarry on Fossil Ridge, between Wapta Mountain and Mount Field, at an elevation of around , around north of the railway town of Field, British Columbia, in the Canadian Rocky Mountains. It is adjacent to Mount Burgess, where Walcott first discovered the Burgess Shale formation. Walcott divided the bed into twelve units based on the rock type and fossil content. Certain fossil beds provide reference levels and ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ogygopsis
''Ogygopsis'' is a genus of trilobite from the Cambrian of Antarctica and North America, specifically the Burgess Shale. It is the most common fossil in the Mt. Stephen fossil beds there, but rare in other Cambrian faunas. Its major characteristics are a prominent glabella with eye ridges, lack of pleural spines, a large spineless pygidium about as long as the thorax or cephalon, and its length: up to 12 cm.Coppold, Murray and Wayne Powell (2006). ''A Geoscience Guide to the Burgess Shale'', p. 56. The Burgess Shale Geoscience Foundation, Field, British Columbia. . File:Ogygopsis reconstruction.jpg, Reconstruction of ''Ogygopsis klotzi'' in the Burgess Shale File:Royal Tyrrell Ogygopsis klotzi.jpg, At the Royal Tyrrell Museum of Palaeontology References * ''Fossils'' (Smithsonian Handbooks) by David Ward (Page 64) ''Ogygopsis''in the Paleobiology Database The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleavage (geology)
Cleavage, in structural geology and petrology, describes a type of planar rock feature that develops as a result of deformation and metamorphism. The degree of deformation and metamorphism along with rock type determines the kind of cleavage feature that develops. Generally, these structures are formed in fine grained rocks composed of minerals affected by pressure solution. Cleavage is a type of rock foliation, a fabric element that describes the way planar features develop in a rock. Foliation is separated into two groups: primary and secondary. Primary deals with igneous and sedimentary rocks, while secondary deals with rocks that undergo metamorphism as a result of deformation. Cleavage is a type of secondary foliation associated with fine grained rocks. For coarser grained rocks, schistosity is used to describe secondary foliation. There are a variety of definitions for cleavage, which may cause confusion and debate. The terminology used in this article is based largely on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oncoid
Oncolites are sedimentary structures composed of oncoids, which are layered structures formed by the growth of one or more species of microorganisms, usually containing cyanobacteria. Oncolites are very similar to stromatolites, but, instead of forming columns, they form approximately spherical structures. The oncoids often form around a central nucleus, such as a shell fragment, and a calcium carbonate structure is deposited by encrusting microbes. Oncolites are indicators of warm waters in the photic zone, but are also known in contemporary freshwater environments. These structures rarely exceed 10 cm in diameter. Oncolites may have either a porostromate or spongiostromate texture. Most oncolites are spongiostromate, having no recognisable cellular texture or microstructure. Porostromate oncolites are mostly unknown during the Precambrian; since the Eocene they have mostly been confined to freshwater environments. Distribution The appearance of recent or near-recent fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burgess Shale, Yoho National Park Of Canada
Burgess may refer to: People and fictional characters * Burgess (surname), a list of people and fictional characters * Burgess (given name), a list of people Places Canada * Mount Burgess, a mountain in Yoho National Park, British Columbia England *Burgess Park, a park in London *Burgess Field, a nature reserve in Oxford *Burgess Hill, a town and parish in West Sussex United States * Burgess, Michigan, an unincorporated community *Burgess, Missouri, an unincorporated community * Burgess, South Carolina, an unincorporated community *Burgess, Virginia, an unincorporated community *Burgess Township, Bond County, Illinois, a township *Burgess Branch, a tributary of the Missisquoi River in Vermont Other uses *Burgess (title), a political official or representative *Burgess Company, an American airplane manufacturer *Burgess GAA, an athletic club in Ireland See also *Burgess House (other), several buildings named *Burgess model, or Concentric zone model, a theoret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathedral Escarpment
The Cathedral Formation is a stratigraphic unit in the southern Canadian Rockies of Alberta and British Columbia, on the western edge of the Western Canada Sedimentary Basin. It is a thick sequence of carbonate rocks of Middle Cambrian age. It was named for Cathedral Mountain in Yoho National Park by Charles Doolittle Walcott, the discoverer of the Burgess shale fossils. The Cathedral Formation includes fossil stromatolites, oncolites, and other algal remains, as well as a few shale beds with trilobites. The Cathedral escarpment on its westernmost edge is thought to have played a major role in the deposition and preservation of the Burgess shale fossils. Lithology and deposition The Cathedral Formation consists primarily of massive, cliff-forming carbonate rocks. It was originally deposited as limestone, much of which may have been secreted by marine algae. Deposition took place in shallow water on an extensive algal reef or carbonate platform that had developed along the west ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils Of The Burgess Shale
The fossils of the Burgess Shale, like the Burgess Shale itself, are fossils that formed around 505 million years ago in the mid-Cambrian, Cambrian period. They were discovered in Canada in 1886, and Charles Doolittle Walcott collected over 65,000 specimens in a series of field trips up to the alpine site from 1909 to 1924. After a period of neglect from the 1930s to the early 1960s, new excavations and re-examinations of Walcott's collection continue to reveal new species, and statistical analysis suggests that additional discoveries will continue for the foreseeable future. Stephen Jay Gould's 1989 book ''Wonderful Life (book), Wonderful Life'' describes the history of discovery up to the early 1980s, although his analysis of the implications for evolution has been contested. The fossil beds are in a series of shale layers, averaging and totalling about in thickness. These layers were deposited against the face of a high undersea limestone cliff. All these features were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagerstätte
A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserve a high concentration of fossils, while ''Konservat-Lagerstätten'' offer exceptional fossil preservation, sometimes including preserved soft tissues. ''Konservat-Lagerstätten'' may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying the decomposition of both gross and fine biological features until long after a durable impression was created in the surrounding matrix. ''Fossil-Lagerstätten'' spans geological time from the Neoproterozoic era to the present. Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan shales and Burgess Shale, the Ordovician Soom Shale, the Silurian Waukesha Biota, the Devonian Hunsrück Slates and Gogo Formation, the Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
