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Intermontane Plate
The Intermontane Plate was an ancient oceanic tectonic plate that lay on the west coast of North America about 195 million years ago. The Intermontane Plate was surrounded by a chain of volcanic islands called the Intermontane Islands, which had been accumulating as a volcanic chain in the Pacific Ocean since the Triassic period, beginning around 245 million years ago. The volcanism records yet another subduction zone. Beneath the far edge of the Intermontane microplate, another plate called the Insular Plate was sinking. This arrangement with two parallel subduction zones is unusual. The modern Philippine Islands are located on the Philippine Mobile Belt, one of the few places on Earth where twin subduction zones exist today. Geologists call the ocean between the Intermontane islands and North America the Slide Mountain Ocean. The name comes from the Slide Mountain Terrane, a region made of rocks from the floor of the ancient ocean. Collision of the Intermontane Islands During ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectonic Plate
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slide Mountain Terrane
The Slide Mountain Terrane is a late Paleozoic terrane made of a complex of oceanic rocks in northern and southern British Columbia, Canada. The rocks of the terrane include Carboniferous limestones, fine grained quartz rich clastics, conglomerates and volcanic rocks. Permian Kalso Group mafic volcanics are included. The Kalso Group volcanics originated from an ocean ridge environment adjacent to the Permian continental margin. These oceanic rocks were derived from the seafloor of the prehistoric Slide Mountain Ocean, the Intermontane Plate, which was subducted under the North American plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific .... References Terranes Geology of British Columbia Carboniferous British Columbia Paleozoic British Columbia {{Canada-geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Historical Tectonic Plates
History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the invention of writing systems is considered prehistory. "History" is an umbrella term comprising past events as well as the memory, discovery, collection, organization, presentation, and interpretation of these events. Historians seek knowledge of the past using historical sources such as written documents, oral accounts, art and material artifacts, and ecological markers. History is not complete and still has debatable mysteries. History is also an academic discipline which uses narrative to describe, examine, question, and analyze past events, and investigate their patterns of cause and effect. Historians often debate which narrative best explains an event, as well as the significance of different causes and effects. Historians also debate the nature of history as an end in itself, as well as its usefulness to give perspective on the problems of the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectonic Plates
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continent
A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven regions are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia. "Most people recognize seven continents—Asia, Africa, North America, South America, Antarctica, Europe, and Australia, from largest to smallest—although sometimes Asia and Europe are considered a single continent, Eurasia." Variations with fewer continents may merge some of these, for example America, Eurasia, or Afro-Eurasia are sometimes treated as single continents, which can bring the total number as low as four. Zealandia, a largely submerged mass of continental crust, has also been described as a continent. Oceanic islands are frequently grouped with a nearby continent to divide all the world's land into geographical regions. Under t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermontane Belt
The Intermontane Belt is a physiogeological region in the Pacific Northwest of North America, stretching from northern Washington into British Columbia, Yukon, and Alaska. It comprises rolling hills, high plateaus and deeply cut valleys. The rocks in the belt have very little similarities with the North American continent. Geology The formation of the Intermontane Belt is complex. It began forming during the early Jurassic period when an island arc called the Intermontane Islands collided against a pre-existing continental margin. This island arc is believed to have formed on a pre-existing tectonic plate called the Intermontane Plate about 245 million years ago by subduction of the former Insular Plate during the Triassic period. This subduction zone records another subduction zone called the Intermontane Trench under an ancient ocean between the Intermontane Islands and the former continental margin of North America called the Slide Mountain Ocean. This arrangement of two par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) contain almost no dark minerals. Granite is nearly alway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Northwest
The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common conception includes the U.S. states of Oregon, Washington (state), Washington, and Idaho, and the Canadian province of British Columbia. Some broader conceptions reach north into Alaska and Yukon, south into northern California, and east into western Montana. Other conceptions may be limited to the coastal areas west of the Cascade Mountains, Cascade and Coast Mountains, Coast mountains. The variety of definitions can be attributed to partially overlapping commonalities of the region's history, culture, geography, society, ecosystems, and other factors. The Northwest Coast is the coastal region of the Pacific Northwest, and the Northwest Plateau (also commonly known as "British Columbia Interi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slide Mountain Ocean
The Slide Mountain Ocean was an ancient ocean that existed between the Intermontane Islands and North America beginning around 245 million years ago in the Triassic period. It is named after the Slide Mountain Terrane, which is composed of rocks from the ancient oceanic floor. There was a subduction zone on the Slide Mountain Ocean's floor called the Intermontane Trench where the Intermontane Plate The Intermontane Plate was an ancient oceanic tectonic plate that lay on the west coast of North America about 195 million years ago. The Intermontane Plate was surrounded by a chain of volcanic islands called the Intermontane Islands, which had b ... was being subducted under North America. The floor of the Slide Mountain Ocean was pushed up onto the ancient margin of North America. References Historical oceans Triassic paleogeography {{triassic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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