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Gates Formation
The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881. Lithology The Fort St. John Group is mostly composed of dark shale deposited in a marine environment. Bentonite is present in the shale, and it is interbedded with sandstone, siltstone and conglomerates. Distribution The Fort St. John Group occurs in the subsurface in the Peace River Country of northeastern British Columbia and north-western Alberta, in southern Yukon and southern Northwest Territories. It has a thickness of to . Relationship to other units The Fort St. John Group is conformably overlain by the Dunvegan Formation and conformably underlain by the Bullhead Group or may rest disconformably on older units. Subdivisions The Fort St. John Group is subdivided into the following formations: Canadian Rockies foothills of British C ... [...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 Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, forests, lakes, mountains, inland deserts and grassy plains, and borders the province of Alberta to the east and the Yukon and Northwest Territories to the north. With an estimated population of 5.3million as of 2022, it is Canada's third-most populous province. The capital of British Columbia is Victoria and its largest city is Vancouver. Vancouver is the third-largest metropolitan area in Canada; the 2021 census recorded 2.6million people in Metro Vancouver. The first known human inhabitants of the area settled in British Columbia at least 10,000 years ago. Such groups include the Coast Salish, Tsilhqotʼin, and Haida peoples, among many others. One of the earliest British settlements in the area was Fort Victoria, established ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name. As a unit of geologic time measure, the Cenomanian Age spans the time between 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya. The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States. At the end of the Cenomanian, an anoxic event took place, called the Cenomanian-Turonian boundary event or the "Bonarelli event", that is associated with a minor extinction event for marine spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma (million years ago). The Albian is preceded by the Aptian and followed by the Cenomanian. Stratigraphic definitions The Albian Stage was first proposed in 1842 by Alcide d'Orbigny. It was named after Alba, the Latin name for River Aube in France. A Global Boundary Stratotype Section and Point (GSSP), ratified by the IUGS in 2016, defines the base of the Albian as the first occurrence of the planktonic foraminiferan '' Microhedbergella renilaevis'' at the Col de Pré-Guittard section, Arnayon, Drôme, France. The top of the Albian Stage (the base of the Cenomanian Stage and Upper Cretaceous Series) is defined as the place where the foram species '' Rotalipora globotruncanoides'' first appears in the stratigraphic column. The Albia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological 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] |
Canadian Rockies
The Canadian Rockies (french: Rocheuses canadiennes) 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, which is the northern segment of the North American Cordillera, the expansive system of interconnected mountain ranges between the Interior Plains and the Pacific Coast that runs northwest–southeast from central Alaska to the Isthmus of Tehuantepec in Mexico. Canada officially defines the Rocky Mountains system as the mountain chains east of the Rocky Mountain Trench extending from the Liard River valley in northern British Columbia to the Albuquerque Basin in New Mexico, not including the Mackenzie, Richardson and British Mountains/Brooks Range in Yukon and Alaska (which are all included as the "Arctic Rockies" in the United States' definition of the Rocky Mountains system). The Canadian Rockies, bein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unconformity
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger layer, but the term is used to describe any break in the sedimentary geologic record. The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at Siccar Point in 1788. The rocks above an unconformity are younger than the rocks beneath (unless the sequence has been overturned). An unconformity represents time during which no sediments were preserved in a region or were subsequently eroded before the next deposition. The local record for that time interval is missing and geologists must use other clues to discover that part of the geologic history of that area. The interval of geologic time not represented is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northwest Territories
The Northwest Territories (abbreviated ''NT'' or ''NWT''; french: Territoires du Nord-Ouest, formerly ''North-Western Territory'' and ''North-West Territories'' and namely shortened as ''Northwest Territory'') is a federal territory of Canada. At a land area of approximately and a 2016 census population of 41,790, it is the second-largest and the most populous of the three territories in Northern Canada. Its estimated population as of 2022 is 45,605. Yellowknife is the capital, most populous community, and only city in the territory; its population was 19,569 as of the 2016 census. It became the territorial capital in 1967, following recommendations by the Carrothers Commission. The Northwest Territories, a portion of the old North-Western Territory, entered the Canadian Confederation on July 15, 1870. Since then, the territory has been divided four times to create new provinces and territories or enlarge existing ones. Its current borders date from April 1, 1999, when the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yukon
Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as of March 2022. Whitehorse, the territorial capital, is the largest settlement in any of the three territories. Yukon was split from the North-West Territories in 1898 as the Yukon Territory. The federal government's ''Yukon Act'', which received royal assent on March 27, 2002, established Yukon as the territory's official name, though ''Yukon Territory'' is also still popular in usage and Canada Post continues to use the territory's internationally approved postal abbreviation of ''YT''. In 2021, territorial government policy was changed so that “''The'' Yukon” would be recommended for use in official territorial government materials. Though officially bilingual (English and French), the Yukon government also recognizes First Natio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Territories (NWT) to the north, and the U.S. state of Montana to the south. It is one of the only two landlocked provinces in Canada (Saskatchewan being the other). The eastern part of the province is occupied by the Great Plains, while the western part borders the Rocky Mountains. The province has a predominantly continental climate but experiences quick temperature changes due to air aridity. Seasonal temperature swings are less pronounced in western Alberta due to occasional Chinook winds. Alberta is the fourth largest province by area at , and the fourth most populous, being home to 4,262,635 people. Alberta's capital is Edmonton, while Calgary is its largest city. The two are Alberta's largest census metropolitan areas. More tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peace River Country
The Peace River Country (or Peace Country; french: Région de la Rivière-de-la-paix) is an aspen parkland region centring on the Peace River in Canada. It extends from northwestern Alberta to the Rocky Mountains in northeastern British Columbia, where a certain portion of the region is also referred to as the Peace River Block. Geography The Peace River Country includes the incorporated communities of Fort St. John, Dawson Creek, Tumbler Ridge and Chetwynd in British Columbia. Major communities in the Alberta portion of the Peace Country include Grande Prairie, Peace River, High Level and Fairview. It has no fixed boundaries but covers some 260,000 to 390,000 km² (100,000 to 150,000 square miles). In British Columbia, the area extends from Monkman Provincial Park and Tumbler Ridge in the south, to Hudson's Hope and the Williston Lake in the west, to Fort St. John and Charlie Lake in the north. The term is used also in a broader sense to mean the whole of the Northeastern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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