Two-dimensional, phase resolved magnetic probe measurements have been performed in a low pressure inductively coupled cylindrical plasma source driven with a planar coil. The rf electric field and current density distributions determined from these measurements exhibit an abnormal nonmonotonic spatial evolution. Formation of a second current layer, phase bifurcation and a reversal of the rf field phase velocity have been found and are attributed to spatial dispersion of the plasma conductivity due to collisionless electron thermal motion typical of anomalous skin effect. ©1997 American Institute of Physics.