HR: 08:15h
AN: MR31D-02    [Abstracts]
TI: Length scales of magma transport in reactive two-phase flow
AU: * Hier-Majumder, S
EM: saswata@umd.edu
AF: University of Maryland, Department of Geology Building 237, College Park, MD 20742, United States
AU: Takei, Y
EM: ytakei@eri.u-tokyo.ac.jp
AF: University of Tokyo, Earthquake Research Institute, Tokyo, 113-0032, Japan
AB: During magma migration, both interfacial tension and mass exchange between the matrix and the melt play an important role in controlling the efficiency and rate of melt extraction and the chemical signature of the magma. In this work, we develop a new formulation governing the dynamics of a two-phase aggregate coupling effects of interfacial tension and mass exchange between the melt and the matrix by dissolution-precipitation. Dissolution-precipitation, which is limited by the rate and length scales of diffusive mass transport of ions, typically redistributes melt over small length scales. A process likely to dominate in the length scale of laboratory experiments. Rapid diffusive mass redistribution can also significantly reduce the rate of segregation of buoyant small-wavelength melt pockets. Growth or decay of large wavelength melt structures such as melt-rich layers in the Earth's lower mantle, blobs of core-forming material in the proto-Earth, and magma bodies beneath volcanic arcs and midoceanic ridges is dominated by a balance between interfacial tension, buoyancy, and viscous deformation of the matrix. Efficiency of buoyancy-driven extraction of large wavelength melt structures are strongly modulated by interfacial tension depending on the average grain size of the matrix and the state of disaggregation of the matrix.
DE: 3947 Surfaces and interfaces
DE: 5114 Permeability and porosity
DE: 5139 Transport properties
SC: Mineral and Rock Physics [MR]
MN: 2007 Fall Meeting