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Laurentia Leon
Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America. Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although originally it also included the cratonic areas of Greenland and also the northwestern part of Scotland, known as the Hebridean Terrane. During other times in its past, Laurentia has been part of larger continents and supercontinents and itself consists of many smaller terranes assembled on a network of Early Proterozoic orogenic belts. Small microcontinents and oceanic islands collided with and sutured onto the ever-growing Laurentia, and together formed the stable Precambrian craton seen today. The craton is named after the Laurentian Shield, through the Laurentian Mountains, which received their name from the Saint Lawrence River, named after Lawrence of Rome. Interior platform In eastern and central Canada, much of the stable crato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioregion
A bioregion is an ecologically and geographically defined area that is smaller than a biogeographic realm, but larger than an ecoregion or an ecosystem, in the World Wide Fund for Nature classification scheme. There is also an attempt to use the term in a rank-less generalist sense, similar to the terms "biogeographic area" or "biogeographic unit". It may be conceptually similar to an ecoprovince. It is also differently used in the environmentalist context, being coined by Berg and Dasmann (1977). WWF bioregions The World Wide Fund for Nature (WWF) scheme divides some of the biogeographic realms into bioregions, defined as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)." The WWF bioregions are as follows: * Afrotropical realm **Western Africa and Sahel **Central Africa **Eastern and Southern Africa ** Horn of Africa **Madagascar–I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Lawrence River
The St. Lawrence River (french: Fleuve Saint-Laurent, ) is a large river in the middle latitudes of North America. Its headwaters begin flowing from Lake Ontario in a (roughly) northeasterly direction, into the Gulf of St. Lawrence, connecting the American Great Lakes to the North Atlantic Ocean, and forming the primary drainage outflow of the Great Lakes Basin. The river traverses the Canadian provinces of Ontario and Quebec, as well as the U.S. state of New York, and demarcates part of the international boundary between Canada and the United States. It also provides the foundation for the commercial St. Lawrence Seaway. Names Originally known by a variety of names by local First Nations, the St. Lawrence became known in French as ''le fleuve Saint-Laurent'' (also spelled ''St-Laurent'') in 1604 by Samuel de Champlain. Opting for the ''grande riviere de sainct Laurens'' and ''fleuve sainct Laurens'' in his writings and on his maps, de Champlain supplanted previous Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus (organic matter). The geological detritus originated from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or mass movement, which are called agents of denudation. Biological detritus was formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies (marine snow). Sedimentation may also occur as dissolved minerals precipitate from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms, orogens, basins, large igneous provinces, extended crust and oceanic crust. Geological significance Igneous and metamorphic rocks make up 90–95% of the top ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphic Rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by their protolith, their chemical and mineral makeup, and their texture. They may be formed simply by being deeply buried beneath the Earth's surface, where they are subject to high temperatures and the great pressure of the rock layers above. They can also form from tectonic processes such as continental collisions, which cause horizontal pressure, friction, and distorti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Peninsula Of Michigan
The Upper Peninsula of Michigan – also known as Upper Michigan or colloquially the U.P. – is the northern and more elevated of the two major landmasses that make up the U.S. state of Michigan; it is separated from the Lower Peninsula by the Straits of Mackinac. It is bounded primarily by Lake Superior to the north, separated from the Canadian province of Ontario at the east end by the St. Marys River, and flanked by Lake Huron and Lake Michigan along much of its south. Although the peninsula extends as a geographic feature into the state of Wisconsin, the state boundary follows the Montreal and Menominee rivers and a line connecting them. First inhabited by Algonquian-speaking native American tribes, the area was explored by French colonists, then occupied by British forces, before being ceded to the newly established United States in the late 18th century. After being assigned to various territorial jurisdictions, it was granted to the newly formed state of Michigan as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adirondack Mountains
The Adirondack Mountains (; a-də-RÄN-dak) form a massif in northeastern New York with boundaries that correspond roughly to those of Adirondack Park. They cover about 5,000 square miles (13,000 km2). The mountains form a roughly circular dome, about in diameter and about high. The current relief owes much to glaciation. There are more than 200 lakes around the mountains, including Lake George, Lake Placid, and Lake Tear of the Clouds, which is the source of the Hudson River. The Adirondack Region is also home to hundreds of mountain summits, with some reaching heights of or more. Etymology The word Adirondack is thought to come from the Mohawk word ''ha-de-ron-dah'' meaning "eaters of trees". The earliest written use of the name was in 1635 by Harmen Meyndertsz Van Den Bogaert in his Mohawk to Dutch glossary, found in his ''Journey into Mohawk Country''. He spelled it Adirondakx and said that it stood for Frenchmen, meaning the Algonquians who allied with the Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Plains
The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. It is the southern and main part of the Interior Plains, which also include the tallgrass prairie between the Great Lakes and Appalachian Plateau, and the Taiga Plains and Boreal Plains ecozones in Northern Canada. The term Western Plains is used to describe the ecoregion of the Great Plains, or alternatively the western portion of the Great Plains. The Great Plains lies across both Central United States and Western Canada, encompassing: * The entirety of the U.S. states of Kansas, Nebraska, North Dakota and South Dakota; * Parts of the U.S. states of Colorado, Iowa, Minnesota, Missouri, Montana, New Mexico, Oklahoma, Texas and Wyoming; * The southern portions of the Canadian provinces of Alberta, Saskatchewan and Manitoba. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midwest
The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four Census Bureau Region, census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of the United States. It was officially named the North Central Region by the Census Bureau until 1984. It is between the Northeastern United States and the Western United States, with Canada to the north and the Southern United States to the south. The Census Bureau's definition consists of 12 states in the north central United States: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. The region generally lies on the broad Interior Plain between the states occupying the Appalachian Mountains, Appalachian Mountain range and the states occupying the Rocky Mountains, Rocky Mountain range. Major rivers in the region include, from east to west, the Ohio River, the Upper Mis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ga (unit)
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the mean ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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