A microresistivity log made from a tool of the laterolog type with a bucking electrode and two monitor electrodes arranged concentrically on a sidewall pad which is pressed against the formation. The survey current flow is concentrated into a gradually flaring tube shape. Because the spacing is small, the measurement is responsive to the resistivity of a small volume of formation in front of the pad. Measurements of the resistivity of the flushed zone are made. A caliper curve is recorded simultaneously. Compare proximity log and microspherically focused log.