Speculations on the mechanisms for the formation and breakup of supercontinents
The supercontinent cycle has had a profound effect on the Earth's evolution since the Late Archean but our understanding of the forces responsible for its operation remains elusive. Supercontinents appear to form by two end-member processes: extroversion, in which the oceanic lithosphere surrou...
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| Format: | Article |
| Language: | English |
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Elsevier
2013-03-01
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| Series: | Geoscience Frontiers |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S167498711200103X |
| _version_ | 1797757919052169216 |
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| author | J. Brendan Murphy R. Damian Nance |
| author_facet | J. Brendan Murphy R. Damian Nance |
| author_sort | J. Brendan Murphy |
| collection | DOAJ |
| description | The supercontinent cycle has had a profound effect on the Earth's evolution since the Late Archean but our understanding of the forces responsible for its operation remains elusive. Supercontinents appear to form by two end-member processes: extroversion, in which the oceanic lithosphere surrounding the supercontinent (exterior ocean) is preferentially subducted (e.g. Pannotia), and introversion in which the oceanic lithosphere formed between dispersing fragments of the previous supercontinent (interior ocean) is preferentially subducted (e.g. Pangea). Extroversion can be explained by “top–down” geodynamics, in which a supercontinent breaks up over a geoid high and amalgamates above a geoid low. Introversion, on the other hand, requires that the combined forces of slab-pull and ridge push (which operate in concert after supercontinent break-up) must be overcome in order to enable the previously dispersing continents to turn inward. Introversion may begin when subduction zones are initiated along boundaries between the interior and exterior oceans and become trapped within the interior ocean. We speculate that the reversal in continental motion required for introversion may be induced by slab avalanche events that trigger the rise of superplumes from the core-mantle boundary. |
| first_indexed | 2024-03-12T18:22:28Z |
| format | Article |
| id | doaj.art-c921891fdf56482daab70669543d48b6 |
| institution | Directory Open Access Journal |
| issn | 1674-9871 |
| language | English |
| last_indexed | 2024-03-12T18:22:28Z |
| publishDate | 2013-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Geoscience Frontiers |
| spelling | doaj.art-c921891fdf56482daab70669543d48b62023-08-02T08:46:39ZengElsevierGeoscience Frontiers1674-98712013-03-014218519410.1016/j.gsf.2012.07.005Speculations on the mechanisms for the formation and breakup of supercontinentsJ. Brendan Murphy0R. Damian Nance1Department of Earth Sciences, St. Francis Xavier University, Antigonish, Nova Scotia B2G 2W5, CanadaDepartment of Geological Sciences, Ohio University, Athens, OH 45701, USAThe supercontinent cycle has had a profound effect on the Earth's evolution since the Late Archean but our understanding of the forces responsible for its operation remains elusive. Supercontinents appear to form by two end-member processes: extroversion, in which the oceanic lithosphere surrounding the supercontinent (exterior ocean) is preferentially subducted (e.g. Pannotia), and introversion in which the oceanic lithosphere formed between dispersing fragments of the previous supercontinent (interior ocean) is preferentially subducted (e.g. Pangea). Extroversion can be explained by “top–down” geodynamics, in which a supercontinent breaks up over a geoid high and amalgamates above a geoid low. Introversion, on the other hand, requires that the combined forces of slab-pull and ridge push (which operate in concert after supercontinent break-up) must be overcome in order to enable the previously dispersing continents to turn inward. Introversion may begin when subduction zones are initiated along boundaries between the interior and exterior oceans and become trapped within the interior ocean. We speculate that the reversal in continental motion required for introversion may be induced by slab avalanche events that trigger the rise of superplumes from the core-mantle boundary.http://www.sciencedirect.com/science/article/pii/S167498711200103XSupercontinent cycleIntroversionExtroversionPangeaRodiniaPannotia |
| spellingShingle | J. Brendan Murphy R. Damian Nance Speculations on the mechanisms for the formation and breakup of supercontinents Geoscience Frontiers Supercontinent cycle Introversion Extroversion Pangea Rodinia Pannotia |
| title | Speculations on the mechanisms for the formation and breakup of supercontinents |
| title_full | Speculations on the mechanisms for the formation and breakup of supercontinents |
| title_fullStr | Speculations on the mechanisms for the formation and breakup of supercontinents |
| title_full_unstemmed | Speculations on the mechanisms for the formation and breakup of supercontinents |
| title_short | Speculations on the mechanisms for the formation and breakup of supercontinents |
| title_sort | speculations on the mechanisms for the formation and breakup of supercontinents |
| topic | Supercontinent cycle Introversion Extroversion Pangea Rodinia Pannotia |
| url | http://www.sciencedirect.com/science/article/pii/S167498711200103X |
| work_keys_str_mv | AT jbrendanmurphy speculationsonthemechanismsfortheformationandbreakupofsupercontinents AT rdamiannance speculationsonthemechanismsfortheformationandbreakupofsupercontinents |