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Supercontinents : ウィキペディア英語版 | Supercontinent
In geology, a supercontinent is the assembly of most or all of the Earth's continental blocks or cratons to form a single large landmass.〔Rogers, John J.W., and M. Santosh. Continents and Supercontinents. Oxford: Oxford UP, 2004. Print.〕〔(Configuration of Columbia, a Mesoproterozoic Supercontinent by John J.W. Rogers and M. Santosh 2002 )〕 However, the definition of a supercontinent can be ambiguous. Many earth scientists, such as P.F. Hoffman (1999), use the term "supercontinent" to mean "a clustering of nearly all continents".〔Hoffman, P.F., "The break-up of Rodinia, Birth of Gondwana, True Polar Wander and the Snowball Earth". Journal of African Earth Sciences, 17 (1999): 17–33.〕 This definition leaves room for interpretation when labeling a continental body and is easier to apply to Precambrian times.〔Bradley, Dwight C., "Secular Trends in the Geologic Record and the Supercontinent Cycle." Earth Science Review. (2011): 1–18.〕 Using the first definition provided here, Gondwana (aka Gondwanaland) is not considered a supercontinent, because the landmasses of Baltica, Laurentia and Siberia also existed at the same time but physically separate from each other.〔 The landmass of Pangaea is the collective name describing all of these continental masses when they were in a close proximity to one another. This would classify Pangaea as a supercontinent. According to the definition by Rogers and Santosh (2004), a supercontinent does not exist today. Supercontinents have assembled and dispersed multiple times in the geologic past (see table). The positions of continents have been accurately determined back to the early Jurassic. However, beyond , continental positions are much less certain.〔Flutaeu, Frédéric. "Earth dynamics and climate changes". C. R. Geoscience 335 (2003): 157–174.〕 ==Supercontinents throughout geologic history== The following table displays historical supercontinents, using a general definition.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Supercontinent」の詳細全文を読む
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