Chromitite formation as a result of interaction between serpentinized upper mantle and basaltic magma

Chromitite formation is a matter of debates. Recent model (Borisova et
al., 2012) based on investigation of chromite-hosted inclusions from the
chromitites of Moho Transition Zone (MTZ), Oman ophiolite, proposes the
MTZ chromitites to be a product of assimilation of serpentinized mantle
protolith by mid-ocean ridge basalt (MORB). Our study experimentally
constrains this model. We performed piston-cylinder and internally
heated pressure vessel runs at temperatures of 1250 – 1300 C and in
pressure range from 0.2 to 1.0 GPa. Our results demonstrate that the
Oman  chromitites from Moho Transition Zone can be produced as a result
of no-equilibrium process of serpentinized upper mantle assimilation by
basaltic magma at 0.2 GPa.