  The creep tide theory is used to establish the basic equations of the tidal
evolution of differentiated bodies formed by aligned homogeneous layers in
co-rotation. The mass concentration of the body is given by the fluid Love
number $k_f$. The formulas are given by series expansions valid for high
eccentricity systems. They are equivalent to Darwin's equations, but formally
more compact. An application to the case of Enceladus, with $k_f=0.942$, is
discussed.
