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Physical, chemical, and chronological characteristics of continental mantle
Author(s) -
Carlson Richard W.,
Pearson D. Graham,
James David E.
Publication year - 2005
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1029/2004rg000156
Subject(s) - geology , mantle (geology) , mantle wedge , earth's internal heat budget , hotspot (geology) , transition zone , oceanic crust , continental crust , mantle convection , crust , adakite , geophysics , plate tectonics , subduction , earth science , paleontology , tectonics
Unlike in the ocean basins where the shallow mantle eventually contributes to the destruction of the overlying crust, the shallow mantle beneath continents serves as a stiff, buoyant “root” whose presence may be essential to the long‐term survival of continental crust at Earth's surface. These distinct roles for subcrustal mantle come about because the subcontinental mantle consists of a thick section of material left behind after extensive partial melt extraction, possibly from the wedge of mantle overlying a subducting oceanic plate. Melt removal causes the continental mantle to be cold and strong but also buoyant compared to oceanic mantle. These characteristics allow thick sections of cold mantle to persist beneath continental crust in some cases for over 3 billion years. If the continental mantle becomes gravitationally unstable, however, its detachment from the overlying crust can cause major episodes of intracontinental deformation and volcanism.