Constraining composition of Mars using geophysical constraints and mineral physics data
Abstract
We use the observed moment of inertia, hydrostatic flattening factor and hydrostatic gravitational field to constrain the mineralogical and compositional structures of Mars. We construct 1-D density models of the interior of Mars for a series of mantle temperature and compositional models, core density and core radius. We then adopt the second-order internal theory of equilibrium of a self-gravitating and rotating planet to calculate the hydrostatic figure and flattening factor of Mars, and compare them to the observations. In the mineral physics calculations of density models in the mantle, we consider both olivine and garnet systems and the chemical interactions between them, and use the phase equilibria data to define the stable assemblages at relevant pressures and temperatures, and cation distribution data to define the chemical composition of each phase. This information, along with our current estimates of physical properties of these phases, provides a mineralogical model with volume fractions of each phase along with the aggregate velocities and density. Following this approach, we document compositional and thermal models of the interior of Mars that are consistent with the mineral physics data and the geophysical constraints of hydrostatic figure, flattening factor and moment of inertia. We also discuss the implications of these compositional and thermal models to the understanding of formation and evolution of the planet.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.P33B1450W
- Keywords:
-
- 3612 Reactions and phase equilibria (1012;
- 8412);
- 3672 Planetary mineralogy and petrology (5410);
- 5410 Composition (1060;
- 3672);
- 5430 Interiors (8147);
- 6225 Mars