Utilizing 40Ar/39Ar plateau ages for selected field reversals at ~1, 2, 10, 16 and 34 Ma, a geomagnetic polarity time scale (GPTS) is constructed, following the technique of Cande and Kent [1992>. This differs markedly from previous GPTS, especially in middle-late Miocene time; the ages for the chrons in post-Miocene time are in agreement with values derived by the astrochronological technique. Refinements in this GPTS await acquisition of 40Ar/39Ar plateau ages for field reversals in the time frames 3--8 Ma and 11--15 Ma. ¿ American Geophysical Union 1993