Plate tectonics: Difference between revisions
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'''Plate tectonics''' in geology is a [[Scientific method|scientific theory]] which explains many features of our planet, as the existance of continents and oceans and their movements though [[Geologic time scale|geologic time]]. It also provides an explanation for [[mountain]] ranges, [[deep-sea trench]]es and [[mid-ocean ridge]]s. As such it is a theory broad in scope and rooted in fundamental physical principles, explaining many geological features previously only understood piecemeal using ad hoc [[hypothesis|hypotheses]]. | '''Plate tectonics''' in geology is a [[Scientific method|scientific theory]] which explains many features of our planet, as the existance of continents and oceans and their movements though [[Geologic time scale|geologic time]]. It also provides an explanation for [[mountain]] ranges, [[deep-sea trench]]es and [[mid-ocean ridge]]s. As such it is a theory broad in scope and rooted in fundamental physical principles, explaining many geological features previously only understood piecemeal using ad hoc [[hypothesis|hypotheses]]. | ||
Conventionally the earth has 3 major layers: [[crust]] - the outermost layer, [[Mantle (geology)|mantle]] and [[Core (geology)|core]]. Until the early 1960s, with the exception of a very few people such as Alfred Wegener and [[Arthur Holmes]], most scientists believed the continents and seas to be largely static. It was believed "local" crustal movement formed mountain ranges, understood by the [http://www.uwgb.edu/DutchS/platetec/geosync.htm geosyncline concept] which had been elaborated in the latter 19th century. | Conventionally the earth has 3 major layers: [[crust]] - the outermost layer, [[Mantle (geology)|mantle]] and [[Core (geology)|core]]. [[Continent]]s and [[ocean]]s are both features of the crust. Until the early 1960s, with the exception of a very few people such as Alfred Wegener and [[Arthur Holmes]], most scientists believed the continents and seas to be largely static. It was believed "local" crustal movement formed mountain ranges, understood by the [http://www.uwgb.edu/DutchS/platetec/geosync.htm geosyncline concept] which had been elaborated in the latter 19th century. | ||
Arguments for an early "super-continent" which split apart over eons were put forward by [[Alfred Wegener]], a German physicist born in 1880, in his book [http://caliban.mpiz-koeln.mpg.de/~stueber/wegener/text/IMG_4853.html ''Die Entstehung der Kontinente und Ozeane''] (''The Origin of Continents and Oceans'' - first edition 1915). His theory was based on several significant coincidences which, taken together, convinced him that the continents had split apart from an enormous land mass he called [[Pangaea]] (translated: whole earth), which he believed existed millions of years in the past. Among the coincidences he was trying to explain was the way the shapes of continents seemed to fit together, for example [[Africa]] to [[South America]]. | Arguments for an early "super-continent" which split apart over eons were put forward by [[Alfred Wegener]], a German physicist born in 1880, in his book [http://caliban.mpiz-koeln.mpg.de/~stueber/wegener/text/IMG_4853.html ''Die Entstehung der Kontinente und Ozeane''] (''The Origin of Continents and Oceans'' - first edition 1915). His theory was based on several significant coincidences which, taken together, convinced him that the continents had split apart from an enormous land mass he called [[Pangaea]] (translated: whole earth), which he believed existed millions of years in the past. Among the coincidences he was trying to explain was the way the shapes of continents seemed to fit together, for example [[Africa]] to [[South America]]. | ||
Revision as of 11:11, 26 January 2008
Plate tectonics in geology is a scientific theory which explains many features of our planet, as the existance of continents and oceans and their movements though geologic time. It also provides an explanation for mountain ranges, deep-sea trenches and mid-ocean ridges. As such it is a theory broad in scope and rooted in fundamental physical principles, explaining many geological features previously only understood piecemeal using ad hoc hypotheses.
Conventionally the earth has 3 major layers: crust - the outermost layer, mantle and core. Continents and oceans are both features of the crust. Until the early 1960s, with the exception of a very few people such as Alfred Wegener and Arthur Holmes, most scientists believed the continents and seas to be largely static. It was believed "local" crustal movement formed mountain ranges, understood by the geosyncline concept which had been elaborated in the latter 19th century.
Arguments for an early "super-continent" which split apart over eons were put forward by Alfred Wegener, a German physicist born in 1880, in his book Die Entstehung der Kontinente und Ozeane (The Origin of Continents and Oceans - first edition 1915). His theory was based on several significant coincidences which, taken together, convinced him that the continents had split apart from an enormous land mass he called Pangaea (translated: whole earth), which he believed existed millions of years in the past. Among the coincidences he was trying to explain was the way the shapes of continents seemed to fit together, for example Africa to South America.
Wegener elaborated the theory of continental drift, which assumed that the continents 'plowed' through the oceans, and can be considered a precursor to modern plate tectonics. ..