1. A method of evaluating invasion of a borehole fluid into an earth formation, the method comprising: (a) conveying into a borehole in the earth formation a resistivity measuring instrument having at least one transmitter and a plurality of pairs of receivers spaced apart from the at least one transmitter; (b) activating the at least one transmitter at at least one frequency and inducing signals in the plurality of pairs of receivers, the induced signals indicative of the resistivity of at least three subzones inside an invaded zone; and (c) filtering the induced signals from the plurality of pairs of receivers and providing an estimate of a resistivity of the at least three subzones.