Linking the Wilson Cycle to deep Earth processes (Invited)
Abstract
Over the past century description of the movement and deformation of the Earth's outer layer has evolved from the hypothesis of Continental Drift into Sea-Floor Spreading and thence to the theory of Plate Tectonics. This theory is as fundamentally unifying to the Earth Sciences as Darwin's Evolution Theory is to Life Science. By 1968 Tuzo Wilson had identified three basic elements of geodynamics: plate tectonics, mantle plumes of deep origin and the Wilson cycle of ocean opening and closing, which provides evidence of plate tectonic behavior in times before quantifiable plate rotations. We have recently shown that deep-seated plumes of the past have risen only from narrow plume generation zones (PGZs) at the Core Mantle Boundary and mostly on the edges of two Large Low Shear wave Velocity Provinces (LLSVPs) that have been stable, antipodal and equatorial in their present positions for hundreds of millions of years and perhaps for much longer. Even though links between mantle activity and plate tectonics are becoming more evident, notably through subsurface tomographic images, advances in mineral physics and much improved absolute plate motion reference frames, a need now is to generate a new Earth model embodying plate tectonics, shallow and deep mantle convection, including such elements as deeply subducted slabs and stable LLSVPs with plumes that rise only from PGZs on the CMB.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.T11G..05T
- Keywords:
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- 8125 TECTONOPHYSICS / Evolution of the Earth;
- 8137 TECTONOPHYSICS / Hotspots;
- large igneous provinces;
- and flood basalt volcanism;
- 8147 TECTONOPHYSICS / Planetary interiors;
- 8157 TECTONOPHYSICS / Plate motions: past