Petrological geodynamic modeling of mid-ocean ridges

作者：Tirone M^*; Sen G; Morgan J P

来源：Physics of the Earth and Planetary Interiors, 2012, 190: 51-70.

DOI：10.1016/j.pepi.2011.10.008

• Mid-ocean ridge
• Mantle melting
• Thermodynamics
• Geodynamics
• Numerical modeling
• Abyssal peridotites

Mid-ocean ridges are the primary location where the Earth's oceanic crust is formed. Beneath spreading ridges several processes such as dynamic melting and partial crystallization modify the petrology of the upper mantle and affect the Earth's global geochemical evolution. A unified picture of the temporal and spatial evolution of melt and residual mantle, as well as crustal production and melt dynamics requires a comprehensive model that takes into account simultaneously the complexity of the physical processes involved and the petrological variations of the ridge system. Here we present the first results of a 2-D numerical approach applied to a spreading ridge that fully couples a two-phase flow model for melt and solid mantle and a chemical thermodynamic model which provides a spatial and temporal description of the minerals and melt abundance and composition. The most significant features found by this study are the following. (1) Accumulation of melt is observed at the base of the lithosphere in the off-axis region (The interpretation of the petrological results needs to be carefully evaluated to ensure that the time and space scale of the numerical model complies with the constraints provided by solid-melt rective experiments and the spatial scale of the petrological structures observed in mid-ocean ridges. (7) Melt distribution and thermal structure are revealed by the seismic shear wave map computed from the numerical model. Certain observations, such as the extent of the melting region, overall agree quite well with the evidences from seismic studies from various ridge settings.

• 出版日期2012-1