The middle Pliocene to earliest Pleistocene part of the Rangitikei River section in Wanganui Basin contains at least six distal tephras--five are rhyolitic (Kowhai, Eagle Hill, Ohingaiti, Waipura and Vinegar Hill tephras) and one is andesitic (Mangamako Tephra). All tephras occur as macroscopic layers and are enclosed within cyclothemic marine sediments that accumulated in shoreface to outer shelf water depths under conditions of oscillating sea level driven by glacio-eustacy. The glass and ferromagnesian compositions of the silicic tephras imply derivation from calc-alkaline rhyolitic sources, either or both of Taupo Volcanic Zone and southern Coromandel Volcanic Zone. The Waipuru and Vinegar Hill tephras have isothermal plateau fission-track (ITPFT) ages of 1.87 ± 0.15 Ma and 1.75 ± 0.13 Ma, respectively. Paleomagnetic results allow identification of (i) the Gauss/Matuyama boundary located ca. 70 m below the top of the Mangaweka Mudstone; and (ii) the top of the Olduvai Subchron, placed at the base of the Waipuru Shellbed. The ITPFT ages of the tephras are consistent with the interpreted magnetostratigraphy and also with astronomically tuned timescales. Correlation of the Rangitikei sequences to the ODP site 846 δ 1 8 O record indicates that each sequence corresponds to a glacial/interglacial isotope stage couplet, and allows ages to be interpolated for tephras not dated directly. Integration of the new ages for the Waipuru and Vinegar Hill tephras, the magnetostratigraphy, and the sequence correlations to the astronomically tuned oxygen isotope timescale, lead us to place the Pliocene-Pleistocene boundary, as defined at the Vrica stratotype, at the base of the highstand systems tract siltstone of Sequence 17 in the Rangitikei section, 60 m below the Vinegar Hill Tephra.