Stability of a compressible hydrous melt layer above the transition zone
نویسندگان
چکیده
Article history: Seismic and mineral physic Received 24 April 2008 Received in revised form 10 October 2008 Accepted 21 November 2008 Available online 13 January 2009
منابع مشابه
On the dynamics of a hydrous melt layer above the transition zone
[1] The ‘‘transition zone water filter’’ (Bercovici and Karato, 2003) model relies on the presence of a dense hydrous melt above the 410-km discontinuity that is formed by dehydration melting as wet wadsleyite undergoes a phase change to low-water-solubility olivine. Recent studies suggest that, particularly in the Pacific, there is sufficient water in the transition zone for dehydration meltin...
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The mechanisms that drive the upwelling of chemical heterogeneity from the lower to upper mantle (e.g., thermal versus compositional buoyancy) are key to our understanding of whole mantle convective processes. We address these issues through a receiver function study on new seismic data from recent deployments located on the Afar Triple Junction, a location associated with deep mantle upwelling...
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Hydrous silicate melts appear to have greater compressibility relative to anhydrous melts of the same composition at low pressures (<2GPa); however, at higher pressures, this difference is greatly reduced and becomes very small at pressures above 5GPa. This implies that the pressure effect on the partial molar volume of water in silicate melt ( partial differentialV-H2O/ partial differentialP) ...
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In the transition-zone water-filter hypothesis, (see main text), water is assumed essentially trapped within the transition zone because of dehydration melting of ambient upwelling at 410km and exsolution of water from slabs at 660km. The assumption that recycling of water is closed allows us to develop a simple theoretical model with which to predict various important parameters such as the me...
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