The paleomagnetic chronology established for a Pliocene-Early Pleistocene sequence of marine sediments in New Zealand reveals that marked climatic coolings based on Foraminifera and oxygen isotope ratios in the late Cenozoic preceded the Pliocene-Pleistocene boundary, which is taken to be at the base of the Gilsá geomagnetic polarity event (1.79 million years ago). Major temperature fluctuations occur from the upper Gauss (Middle Pliocene) to middle Matuyama (Early Pleistocene). The first major Pliocene cooling spans the Gauss-Matuyama boundary (2.43 million years ago). A uniform and rapid (40 centimeters per 1000 years) rate of deposition is shown for the moderately shallow marine environment.