Imaging proto-oceanic crust off the Brazilian Continental Margin
نویسندگان
چکیده
منابع مشابه
Continental crust generated in oceanic arcs
Thin oceanic crust is formed by decompression melting of the upper mantle at mid-ocean ridges, but the origin of the thick and buoyant continental crust is enigmatic. Juvenile continental crust may form from magmas erupted above intraoceanic subduction zones, where oceanic lithosphere subducts beneath other oceanic lithosphere. However, it is unclear why the subduction of dominantly basaltic oc...
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T h e problem of the origin of the cont inental crust can be resolved into two fundamenta l quest ions: (1) the lo cation and mechani sms of init ial m a n t l e extract ion of the primitive crust and (2) the processes by which this primitive crust is converted into the cont inental crust that presently exists . W e know that Archean cont inen tal crust is compos i t iona l ly dist inct from ...
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The continental crust is 41.4 km thick on average and covers 39% of the Earth’s surface. Information from the isotopic and trace element composition of >4-billion-yearold (Ga) zircon grains and the evolution of mantle isotopic reservoirs indicates that 75%, and possibly more, of the continental crust was created before 2.5 Ga (Harrison 2009; Belousova et al. 2010). Thus, the continental crust i...
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ژورنال
عنوان ژورنال: Geophysical Journal International
سال: 2014
ISSN: 1365-246X,0956-540X
DOI: 10.1093/gji/ggu387