Bina, C. R., Petrological interpretation of seismic structure, Abstracts of the Euroconference on The Deep Earth: Theory, Experiment and Observation: Large Scale Processes and Properties, Acquafredda di Maratea, Italy, 1999.
Others at this conference will discuss the properties of the upper mantle and transition zone. Therefore, I will focus upon the structure and composition of the lower mantle, in terms of the potential for both radial and lateral heterogeneity.
With regard to radial heterogeneity, I will discuss the determination of model lower mantle compositions which best fit seismological profiles of density and bulk sound velocity. In this context, I will address the effects of uncertainties in mantle temperatures, Fe-Mg partitioning between coexisting mineral phases, and the role of calcium silicate perovskite. I will also note the potential for unusual boundary layer structures.
With regard to lateral heterogeneity, I will make some observations on the interpretation of lateral seismic velocity variations, as revealed for example by seismic tomography, in terms of perturbations to temperature, composition, and other variables, and I will note the possible importance of associated density anomalies. Furthermore, I will comment on the significance of lateral covariation in P- and S-wave velocities and the depth-dependence of this parameter.Copyright © 1999 European Science Foundation