Abstract
We conducted phase transformation experiments (1) from supinel lherzolite to garnet lherzoltite and (2) from garnet lherzolite to spinel lherzolite in order to study the mechanism and kinetics of these reactions.
Experiments were conducted (1) at 3.2 GPa, 1000-1200 °C and for 0.6-30 hours with a spinel single crystal embedded into powder mixture of orthopyroxene and clinopyroxene and (2) at 1.2 GPa, 1000-1100 °C and for 5-30 hours with a garnet single crystal embedded into powdered olivine.
As results, (1) the garnet reaction rim was formed between single crystalline spinel and polycrystalline pyroxenes. The kinetics of the reaction rim growth was analysed based on the diffusion-controlled growth mechanism. (2) Partial melting occured and the orthopyroxene reaction rim and spinel domain were formed between single crystalline garnet and pollycrystalline olivine.
