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Land Bridge
In biogeography, a land bridge is an isthmus or wider land connection between otherwise separate areas, over which animals and plants are able to cross and colonize new lands. A land bridge can be created by marine regression, in which sea levels fall, exposing shallow, previously submerged sections of continental shelf; or when new land is created by plate tectonics; or occasionally when the sea floor rises due to post-glacial rebound after an ice age. Prominent examples Former land bridges * The Bassian Plain, which linked Australia to Tasmania * The Antarctic Land Bridge, which connected South America, Antarctica, and Australia during the Late Cretaceous and Early Paleogene * The Bering Land Bridge (aka Beringia), which intermittently connected Alaska (Northern America) with Siberia (North Asia) as sea levels rose and fell under the effect of ice ages * GAARlandia, a hypothesized land bridge which potentially connected the Greater Antilles with South America d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fennoscandia
__NOTOC__ Fennoscandia (Finnish language, Finnish, Swedish language, Swedish and ; ), or the Fennoscandian Peninsula, is a peninsula in Europe which includes the Scandinavian Peninsula, Scandinavian and Kola Peninsula, Kola peninsulas, mainland Finland, and Karelia. Administratively, this roughly encompasses the mainlands of Finland, Norway and Sweden, as well as Murmansk Oblast, much of the Republic of Karelia, and parts of northern Leningrad Oblast in Russia. Its name comes from the Latin words ''Fennia'' (Finland) and ''Scandia'' (Scandinavia). The term was first used by the Finnish geologist Wilhelm Ramsay in 1898. Geologically, the area is distinct because its bedrock is Archean granite and gneiss with very little limestone, in contrast to adjacent areas in Europe. The similar term Fenno-Scandinavia is sometimes used for Fennoscandia. Both terms are sometimes used in English to refer to a cultural or political grouping of Finland with Sweden, Norway and Denmark (the latter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Geer Land Bridge
The De Geer Land Bridge was a land bridge that connected Fennoscandia to northern Greenland. The land bridge provided a northern route from Europe to North America from the Late Cretaceous to the Early Paleocene, although this timeframe has been disputed. The De Geer Land Bridge provided a path from Scandinavia across the Barents Sea to Svalbard, northern Greenland, and northern Canada. This may have been possible due to the Barents Sea residing on the shallow continental shelf. Relation to other land bridges The De Geer Land Bridge was the initial route from Europe and North America. Long after the De Geer Land Bridge disappeared, the Thule Land Bridge appeared and offered a more southern route from Europe to North America. Beringia, a land bridge from Northeast Asia to Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Bridges Of Japan
Due to changes in sea level, Japan has at various times been connected to the continent by , with continental Russia to the north via the Sōya Strait, Sakhalin, and the Mamiya Strait, and with the Korean Peninsula to the southwest, via the Tsushima Strait and Korea Strait. Land bridges also connected the Japanese Islands with each other. These land bridges enabled the migration of terrestrial fauna from the continent and their dispersal within Japan. Geological background Around 25 million years ago, the Sea of Japan began to open, separating Japan from the continent and giving rise to the Japanese island arc system of today. The Sea of Japan as a back-arc basin was open both to the northeast and to the southwest by 14 Ma, while marine transgression further contributed to the isolation and insulation of Japan. Due to the level of tectonic activity in the area and significant subsidence of the Japanese Islands since the Miocene, exact quantification of historic sea level ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rupelian
The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian Stage. Name The stage is named after the small river Rupel in Belgium, a tributary to the Scheldt. The Belgian Rupel Group derives its name from the same source. The name Rupelian was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The separation between the group (stratigraphy), group and the stage was made in the second half of the 20th century, when stratigraphers saw the need to distinguish between lithostratigraphy, lithostratigraphic and chronostratigraphy, chronostratigraphic names. Stratigraphic definition The base of the Rupelian Stage (which is also the base of the Oligocene Series) is at the extinction of the foram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priabonian
The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of the Oligocene. '' Priabona'', an extinct dipteran of Pipunculidae family, is named after Priabonian, the age of deposits from which this insect is known. History and naming The Priabonian Stage was introduced in scientific literature by Ernest Munier-Chalmas and Albert de Lapparent in 1893. The stage is named after the small hamlet of Priabona in the community of Monte di Malo, in the Veneto region of northern Italy. Stratigraphic definition The base of the Priabonian Stage is at the first appearance of calcareous nannoplankton species '' Chiasmolithus oamaruensis'' (which forms the base of nanoplankton biozone NP18). An official GSSP was ratified in 2020, and was placed in the Alano di Piave section in Alano di Piave, Bellu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Antilles
The Greater Antilles is a grouping of the larger islands in the Caribbean Sea, including Cuba, Hispaniola, Puerto Rico, and Jamaica, together with Navassa Island and the Cayman Islands. Seven island states share the region of the Greater Antilles, with Haiti and the Dominican Republic sharing the island of Hispaniola. Together with the Lesser Antilles, they make up the Antilles, which along with the Lucayan Archipelago, form the West Indies in the Caribbean region of the Americas. While most of the Greater Antilles consists of independent countries, Puerto Rico and Navassa Island are Territories of the United States, unincorporated territories of the United States, while the Cayman Islands are a British Overseas Territories, British Overseas Territory. The largest island is Cuba, which extends to the western end of the island group. Puerto Rico lies on the eastern end, and the island of Hispaniola, the most populated island, is located in the middle. Jamaica lies to the south of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GAARlandia
The Greater Antilles + Aves Ridge, also known as GAARlandia, is a hypothesized land bridge which is proposed to have connected the Greater Antilles to South America around 33 million years ago (mya). Animal and plant species are thought to have colonisation (biology), colonized the Caribbean Islands through biological dispersal, dispersal and vicariance, and the most prominent vicariance hypothesis involves colonization via GAARlandia. Proponents of the hypothesis cite studies of individual lineage (genetic), lineages, while critics point to a lack of geological evidence. Hypothesis The GAARlandia hypothesis was introduced by Ross MacPhee and Manuel Iturralde-Vinent in 1994. It posits that the North American plate, North American and South American plates compressed the Caribbean plate for 2 million years during the Eocene–Oligocene boundary (33 million years ago), which led the presently-submerged Aves Ridge in the eastern Caribbean Sea to rise and connect South America with Pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Asia
North Asia or Northern Asia () is the northern region of Asia, which is defined in geography, geographical terms and consists of three federal districts of Russia: Ural Federal District, Ural, Siberian Federal District, Siberian, and the Far Eastern Federal District, Far Eastern. North Asia is bordered by the Arctic Ocean to its north; by Eastern Europe to its west; by Central Asia and East Asia to its south; and by the Pacific Ocean and Northern America to its east. It covers an area of , or 8.8% of Earth's total land area; and is the largest subregion of Asia by area, occupying approx. 29.4% of Asia's land area, but is also the least populated, with a population of around 37 million, accounting for merely 0.74% of Asia's population. Topographically, the region is dominated by the Eurasian Plate, except for its eastern part, which lies on the North American Plate, North American, Amurian Plate, Amurian, and Okhotsk Plates. It is divided by three major plains: the West Siberian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siberia
Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states since the lengthy conquest of Siberia, which began with the fall of the Khanate of Sibir in 1582 and concluded with the annexation of Chukotka in 1778. Siberia is vast and sparsely populated, covering an area of over , but home to roughly a quarter of Russia's population. Novosibirsk, Krasnoyarsk, and Omsk are the largest cities in the area. Because Siberia is a geographic and historic concept and not a political entity, there is no single precise definition of its territorial borders. Traditionally, Siberia spans the entire expanse of land from the Ural Mountains to the Pacific Ocean, with the Ural River usually forming the southernmost portion of its western boundary, and includes most of the drainage basin of the Arctic Ocean. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern America
Northern America is the northernmost subregion of North America, as well as the northernmost region in the Americas. The boundaries may be drawn significantly differently depending on the source of the definition. In one definition, it lies directly north of Middle America.Gonzalez, Joseph. 2004"Northern America: Land of Opportunity"(ch. 6). ''The Complete Idiot's Guide to Geography.'' () New York: Alpha Books; pp. 57–8 Northern America's land frontier with the rest of North America then coincides with the Mexico–United States border. Geopolitically, according to the United Nations' scheme of geographical regions and subregions, Northern America consists of Bermuda, Canada, Greenland, Saint Pierre and Miquelon and the United States (the contiguous United States and Alaska only, excluding Hawaii, Navassa Island, Puerto Rico, the United States Virgin Islands, and other minor U.S. Pacific territories). Definitions Maps using the term ''Northern America'' date back to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
