Moho boundary, discovered about a century back, is well established on the basis of seismological studies. Electromagnetic studies using very low frequencies, however, have not been able to establish this boundary due to the presence of highly conducting continental lower crust. Magnetotelluric lithospheric study over the Eastern Indian Craton (3.3 Gyr) resolves the lower crust and upper mantle boundary due to the absence of highly conducting continental lower crust underneath the craton. From the present study it can be speculated that a dynamics other than the plate tectonics possibly existed up to the mid-Archaean.