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Lynx Formation
The Lynx Formation or Lynx Group is a stratigraphic unit of Late Cambrian (Dresbachian) age in the Western Canada Sedimentary Basin. It is present in the Canadian Rockies of Alberta and British Columbia. It was originally described as the Lynx Formation by Charles Doolittle Walcott in 1913, based on and named for outcrops on the slopes of Lynx Mountain on the continental divide east of Mount Robson. It was subdivided into five formations and elevated to group status by J.D. Aitken and R.G. Greggs in 1967.Aitken, J. D and Greggs, R G., 1967. Upper Cambrian formations, southern Rocky Mountains of Alberta, an interim report. Geological Survey of Canada, Paper 66-49. The name Lynx Formation continues to be used in areas where some or all of the subdivisions cannot be distinguished. All of the formations in the Lynx Group include fossil trilobites and some contain the stromatolite '' Collenia''. Lithology and deposition The Lynx Group is composed alternating zones of carbonate rocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphic Unit
A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features (facies) that characterize it. Units must be ''mappable'' and ''distinct'' from one another, but the contact need not be particularly distinct. For instance, a unit may be defined by terms such as "when the sandstone component exceeds 75%". Lithostratigraphic units Sequences of sedimentary and volcanic rocks are subdivided the basis of their shared or associated lithology. Formally identified lithostratigraphic units are structured in a hierarchy of lithostratigraphic rank, higher rank units generally comprising two or more units of lower rank. Going from smaller to larger in rank, the main lithostratigraphic ranks are Bed, Member, Formation, Group and Supergroup. Formal names of lithostratigraphic units are assigned by geological surveys. Units of formation or hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 sedimentary basin consists of a massive wedge of sedimentary rock extending from the Rocky Mountains in the west to the Canadian Shield in the east. This wedge is about thick under the Rocky Mountains, but thins to zero at its eastern margins. The WCSB contains one of the world's largest reserves of petroleum and natural gas and supplies much of the North American market, producing more than per day of gas in 2000. It also has huge reserves of coal. Of the provinces and territories within the WCSB, Alberta has most of the oil and gas reserves and almost all of the oil sands. Conventional oil The WCSB is considered a mature area for exploration of petroleum and recent development has tended toward natural gas and oil sands rather than conventiona ... [...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 minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( 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 ( laminae) less than one centimeter in thickness. This property is called '' 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 more narrow 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 into thin layers, often splintery and usually parallel to the otherwise indistinguishable beddin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolomite (rock)
Dolomite (also known as dolomite rock, dolostone or dolomitic rock) is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite, CaMg(CO3)2. It occurs widely, often in association with limestone and evaporites, though it is less abundant than limestone and rare in Cenozoic rock beds (beds less than about 66 million years in age). The first geologist to distinguish dolomite rock from limestone was Belsazar Hacquet in 1778. Most dolomite was formed as a magnesium replacement of limestone or of lime mud before lithification. The geological process of conversion of calcite to dolomite is known as dolomitization and any intermediate product is known as dolomitic limestone. The "dolomite problem" refers to the vast worldwide depositions of dolomite in the past geologic record in contrast to the limited amounts of dolomite formed in modern times. Recent research has revealed sulfate-reducing bacteria living in anoxic conditions precipitate dolomite which ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonate Rocks
Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and dolomite rock (also known as dolostone), which is composed of mineral dolomite (CaMg(CO3)2). Calcite can be either dissolved by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures. Karst topography and caves develop in carbonate rocks because of their solubility in dilute acidic groundwater. Cooling groundwater or mixing of different groundwaters will also create conditions suitable for cave f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collenia
''Collenia'' is genus of fossil cyanobacteria that form a particular type of stromatolites. Description ''Collenia'' are stromatolites made up of convex layers flattened in the center, forming columnar colonies. The microorganisms involved were likely photosynthetic bacteria expiring oxygen.Carroll Lane Fenton,Pat Vickers Rich,Mildred Adams Fenton,Thomas H. V. RicThe Fossil Book: A Record of Prehistoric Life/ref> Fossil record ''Collenia'' stromatolites were very common in the late Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of th ..., about 2.2 to 2.4 billion years ago. References External links Geological Survey Professional Paper, Volume 669* Spencer G. Lucas,Justin A. Spielmann,Patricia M. Hester,Jason P. Kenworthy,Vincent L. SantuccAmericas Antiquities: 100 Years ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromatolite
Stromatolites () or stromatoliths () are layered sedimentary formations (microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). These microorganisms produce adhesive compounds that cement sand and other rocky materials to form mineral "microbial mats". In turn, these mats build up layer by layer, growing gradually over time. A stromatolite may grow to a meter or more. Although they are rare today, fossilized stromatolites provide records of ancient life on Earth. Morphology Stromatolites are layered, biochemical, accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains in biofilms (specifically microbial mats), through the action of certain microbial lifeforms, especially cyanobacteria. They exhibit a variety of forms and structures, or morphologies, including conical, stratiform, domal, columnar, and branching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. The stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Survey Of Canada
The Geological Survey of Canada (GSC; french: Commission géologique du Canada (CGC)) is a Canadian federal government agency responsible for performing geological surveys of the country, developing Canada's natural resources and protecting the environment. A branch of the Earth Sciences Sector of Natural Resources Canada, the GSC is the country's oldest scientific agency and was one of its first government organizations. History In September 1841, the Province of Canada legislature passed a resolution that authorized the sum of £1,500 sterling be granted to the government for the estimated expense of performing a geological survey of the province. In 1842, the Geological Survey of Canada was formed to fulfill this request.Christy Vodden (1992)No Stone Unturned: The First 150 years of the Geological Survey of Canada Geological Survey of Canada Web site William Edmond Logan was in Montreal at the time and made it known that he was interested in participating in this survey. G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Robson
Mount Robson is the most prominent mountain in North America's Rocky Mountain range; it is also the highest point in the Canadian Rockies. The mountain is located entirely within Mount Robson Provincial Park of British Columbia, and is part of the Rainbow Range. Mount Robson is the second highest peak entirely in British Columbia, behind Mount Waddington in the Coast Range. The south face of Mount Robson is clearly visible from the Yellowhead Highway (Highway 16), and is commonly photographed along this route. Mount Robson was likely named after Colin Robertson, who worked for both the North West Company and the Hudson's Bay Company at various times in the early 19th century, though there was confusion over the name as many assumed it to have been named for John Robson, an early premier of British Columbia. The Texqakallt, a Secwepemc people and the earliest known inhabitants of the area, call it (striped rock), spelled in Dawson 1891 as , ''The Mountain of the Spiral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Divide
A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not connected to the open sea. Every continent on earth except Antarctica (which has no known significant, definable free-flowing surface rivers) has at least one continental drainage divide; islands, even small ones like Killiniq Island on the Labrador Sea in Canada, may also host part of a continental divide or have their own island-spanning divide. The endpoints of a continental divide may be coastlines of gulfs, seas or oceans, the boundary of an endorheic basin, or another continental divide. One case, the Great Basin Divide, is a closed loop around an endoreic basin. The endpoints where a continental divide meets the coast are not always definite since the exact border between adjacent bodies of water is usually not clearly defined. The I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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