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| Titel |
Craton destruction by subduction, collision or plume impingement? Comparisons of some representative cratons in the world |
| VerfasserIn |
Zhensheng Wang, Timothy Kusky, Xiaoyong Li, Xu Wang, Jianmin Fu, Yuefeng Yuan, Peimin Zhu |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104029
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| Publikation (Nr.) |
 EGU/EGU2015-3449.pdf |
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| Zusammenfassung |
| The fact that cratonic lithosphere can be destructed has been demonstrated by numerous
studies. However, the driving force of craton destruction and its mechanism are still
unclear1,2. Subduction, collision and mantle plumes, the most important driving forces for
most geological events, may also be responsible for craton destruction. However, their
relationship in the destruction process including which of them is the major driving force and
how they interact with each other is not understood sufficiently1,2. In this article, the North
China Craton, North Atlantic Craton, Tanzania Craton, Wyoming Craton, Kaapvaal
Craton, Yangtze Craton, Yilgarn Craton and Superior Craton are used as examples to
study their difference and similarities during subduction, collision, or mantle plume
impingement. The work is mainly based on comparison of their tectonic history,
geophysical data, as well as xenolith chronology. It is suggested that large-scale craton
destruction can be influenced by the interaction of subduction, collision and mantle
plumes, acting to different degrees in different examples. Mantle plume related
thermal action enhances the chemical stratification or layering of subcontinental
lithospheric mantle (SCLM), which can form a weak-coupling mid lithosphere
discontinuity (MLD) 3,4,5 and a lower denser SCLM below the MLD. Convergence
(subduction and collision), especially when associated with slab rollback 6, leads to the
regional thinning of the cratonic margin, which is subsequently linked by extension
(mantle plume or slab rollback) related discontinuities. Continuous extension-related
discontinuities extend upward to the MLD depth and cut off the shearing resistance from
adjacent blocks. Next, the lower part of the chemically stratified SCLM in the cratonic
interior is decoupled along the weakly coupled MLD and founders into the deep
asthenosphere 7. Then the destruction of the rest of the lithosphere can be affected by
upwelling related decompression melting and subduction related hydroweakening.
Additionally, if the craton is surrounded by orogenic (mobile) belts, these, can absorb
tectonic energy from collisions, may be aid in the preservation of the cratonic root
8.
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Chen L., et al. (2014). Geology, 42(3): 223-226.
Lenardic, A. et al. (2000). Geophysical Research Letters, 27(8): 1235-1238. |
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