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Hallandian-Danopolonian Event
The Hallandian-Danopolonian event was an orogeny and thermal event that affected Baltica in the Mesoproterozoic. The event metamorphosed pre-existing rocks and generated magmas that crystallized into granite. The Hallandian-Danopolonian event has been suggested to be responsible for forming an east-west alignment of sedimentary basins hosting Jotnian sediments spanning from eastern Norway, to Lake Ladoga in Russia. The alignment of subsidence is thought to correspond to an ancient back-arc basin parallel to a subduction zone Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ... further south. References Orogenies of Europe category:Mesoproterozoic orogenies {{orogeny-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orogeny
Orogeny is a mountain building process. An orogeny is an event that takes place at a convergent plate margin when plate motion compresses the margin. An '' orogenic belt'' or ''orogen'' develops as the compressed plate crumples and is uplifted to form one or more mountain ranges. This involves a series of geological processes collectively called orogenesis. These include both structural deformation of existing continental crust and the creation of new continental crust through volcanism. Magma rising in the orogen carries less dense material upwards while leaving more dense material behind, resulting in compositional differentiation of Earth's lithosphere ( crust and uppermost mantle). A synorogenic process or event is one that occurs during an orogeny. The word "orogeny" () comes from Ancient Greek (, , + , , ). Although it was used before him, the term was employed by the American geologist G. K. Gilbert in 1890 to describe the process of mountain-building as distinguishe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Basin
Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock. They form when long-term subsidence creates a regional depression that provides accommodation space for accumulation of sediments. Over millions or tens or hundreds of millions of years the deposition of sediment, primarily gravity-driven transportation of water-borne eroded material, acts to fill the depression. As the sediments are buried, they are subject to increasing pressure and begin the processes of compaction and lithification that transform them into sedimentary rock. Sedimentary basins are created by deformation of Earth's lithosphere in diverse geological settings, usually as a result of plate tectonic activity. Mechanisms of crustal deformation that lead to subsidence and sedimentary basin formation include the thinning of underlying crust; depression of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian Research
''Precambrian Research'' is a peer-reviewed scientific journal covering the geology of the Earth and its planetary neighbors. It is published by Elsevier and, , the editors-in-chief are V. Pease (Stockholm University) and G.C. Zhao (University of Hong Kong). It was established in 1974. According to the ''Journal Citation Reports'', the journal has a 2013 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 6.023. References External links * * Geology journals Elsevier academic journals English-language journals Publications established in 1974 {{geology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Back-arc Basin
A back-arc basin is a type of geologic basin, found at some convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found in the western Pacific Ocean. Most of them result from tensional forces, caused by a process known as oceanic trench rollback, where a subduction zone moves towards the subducting plate. Back-arc basins were initially an unexpected phenomenon in plate tectonics, as convergent boundaries were expected to universally be zones of compression. However, in 1970, Dan Karig published a model of back-arc basins consistent with plate tectonics. Structural characteristics Back-arc basins are typically very long and relatively narrow, often thousands of kilometers long while only being a few hundred kilometers wide at most. For back-arc extension to form, a subduction zone is required, but not all subduction zones have a back-arc extension feature. Back-arc basins are found in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eighth of Earth's inhabitable landmass. Russia extends across eleven time zones and shares land boundaries with fourteen countries, more than any other country but China. It is the world's ninth-most populous country and Europe's most populous country, with a population of 146 million people. The country's capital and largest city is Moscow, the largest city entirely within Europe. Saint Petersburg is Russia's cultural centre and second-largest city. Other major urban areas include Novosibirsk, Yekaterinburg, Nizhny Novgorod, and Kazan. The East Slavs emerged as a recognisable group in Europe between the 3rd and 8th centuries CE. Kievan Rus' arose as a state in the 9th century, and in 988, it adopted Orthodox Christianity from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Ladoga
Lake Ladoga (; rus, Ла́дожское о́зеро, r=Ladozhskoye ozero, p=ˈladəʂskəjə ˈozʲɪrə or rus, Ла́дога, r=Ladoga, p=ˈladəɡə, fi, Laatokka arlier in Finnish ''Nevajärvi'' ; vep, Ladog, Ladoganjärv) is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, in the vicinity of Saint Petersburg. It is the largest lake located entirely in Europe, the second largest lake after Baikal in Russia, and the 14th largest freshwater lake by area in the world. '' Ladoga Lacus'', a methane lake on Saturn's moon Titan, is named after the lake. Etymology In one of Nestor's chronicles from the 12th century a lake called "the Great Nevo" is mentioned, a clear link to the Neva River and possibly further to Finnish ''nevo'' 'sea' or ''neva'' 'bog, quagmire'. Evgeny Pospelov: ''Geographical names of the world. Toponymic dictionary.'' Second edition. Astrel, Moscow 2001, pp. 106f. Ancient Norse sagas and Hanseatic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Norway
Eastern Norway ( nb, Østlandet, nn, Austlandet) is the geographical region of the south-eastern part of Norway. It consists of the counties Vestfold og Telemark, Viken, Oslo and Innlandet. Eastern Norway is by far the most populous region of Norway. It contains the country's capital, Oslo, which is Norway's most populous city. In Norwegian, the region is called ''Østlandet'' and ''Austlandet'' ("The east land") in contrast to Vestlandet ("The west land"). Geography As of 2015, the region had 2,593,085 inhabitants, 50.4% of Norway's population. The region is bounded by mountains in the north and west, the Swedish border to the east and by Viken and Skagerrak to the south. The border towards Sørlandet is less obvious. The mountains reach a height of 2469 metres in the Jotunheimen mountain range, the highest point in the Nordic countries (excluding Greenland). Other prominent mountain ranges include part of the Dovrefjell in the far north of the region, the Ron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jotnian
In north European geology, Jotnian sediments are a group of Precambrian rocks more specifically assigned to the Mesoproterozoic Era ( Riphean), albeit some might be younger. Jotnian sediments include the oldest known sediments in the Baltic area that have not been subject to metamorphism. Stratigraphically, Jotnian sediments overlie the rapakivi granites and other igneous and metamorphic rocks and are often intruded by younger diabases. Overview Jotnian sediments include quartz-rich sandstones, siltstones, arkose, shale and conglomerates. The characteristic red colour of Jotnian sediments is due to their deposition in subaerial (e.g. non-marine) conditions. Jotnian sediments are the oldest known sediments in the Baltic area that have not been subject to metamorphism. Their age is poorly constrained, but generally they are younger than the rapakivi granites and older than ''Postjotnian'' diabases that intrude the sediments. This means that Jotnian sediments were deposited appr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Episodes (journal)
''Episodes'' is the quarterly journal of the International Union of Geological Sciences, published in Seoul, Korea. In circulation since 1978, Episodes is an international and interdisciplinary open access and free, both to submit and download, publication journal that covers all geoscience disciplines. Episodes includes authoritative articles that reflect global research advances, evolving trends in geoscience disciplines and concise reports on the results of international meetings, conferences, and symposia. It is a high visibility journal, and is indexed in Science Citation Index (SCI), Science Citation Index Expanded (SCIE; Web of Science), and Journal Citation Reports (JCR)/Science Edition, along with many other databases such as SCOPUS. Submitted manuscripts are peer-reviewed, and a first decision is provided to authors approximately within 30 days after submission. See also * List of scientific journals * List of scientific journals in earth and atmospheric sciences A '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Event
A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example of convection, specifically atmospheric convection. Thermals on Earth The Sun warms the ground, which in turn warms the air directly above. The warm air near the surface expands, becoming less dense than the surrounding air. The lighter air rises and cools due to its expansion in the lower pressure at higher altitudes. It stops rising when it has cooled to the same temperature, thus density, as the surrounding air. Associated with a thermal is a downward flow surrounding the thermal column. The downward-moving exterior is caused by colder air being displaced at the top of the thermal. The size and strength of thermals are influenced by the properties of the lower atmosphere (the ''troposphere''). When the air is cold, bubbles of warm ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
