Colloquium: James A. Van Orman

Isotopic studies of meteorites have provided an increasingly detailed picture of the timing of events in the early solar system.  Further progress depends in part on understanding the extent to which isotopic ages are perturbed by thermal processing.  In part 1 of the talk I will discuss our recent work on the ¹⁸²Hf-¹⁸²W and ²⁶Al-²⁶Mg systems, and what these can tell us about processes in the early solar system.

The terrestrial planets have metallic cores that segregated early in their histories.  An important question is whether the metallic core may continue to interact chemically with the rocky mantle during a planet’s subsequent evolution.  Low-density mantle material may dissolve into the core, producing a buoyant layer at the top; conversely, core material may be transferred to the mantle, bringing with it a distinctive geochemical signature.  I will discuss our recent work on the geochemical evolution of planetary cores and experimental constraints on core-mantle interaction.

James A. Van Orman, Associate Professor
Department of Geological Sciences, Case Western Reserve University