From Ocean Drilling Program (ODP) Site 1208 on Shatsky Rise below the Kuroshio Current Extension, we present the North Pacific's first orbital-scale benthic-foraminiferal δ 18 O and δ 13 C time series to span the Pliocene–Pleistocene climate transition. Excellent agreement between the Site 1208 δ 18 O record and the global δ 18 O stack of Lisiecki and Raymo (2005) provides orbital-scale age control and confirms continuous stratigraphy from 3.7 to 1.8Ma at the single-hole site. Cross-spectral analysis of the δ 18 O and δ 13 C time series reveals that these are coherent to 80% confidence at the 41-kyr obliquity band prior to 3.3Ma (glacial isotope stage M2) and increase to the 95% level thereafter. Throughout, δ 18 O cycles consistently lead δ 13 C cycles by ~3kyr. This suggests that global-ocean δ 13 C variations, as produced by terrestrial–marine 12 C transfers, were responsive to obliquity-induced climate changes before the Northern Hemisphere glaciations (NHG) reached mid latitudes at 2.7Ma. In contrast, 41-kyr carbonate sedimentation (as derived from sediment reflectance) cycles, maxima tightly coupled to (>95% confidence) and in phase with minima in the δ 18 O record, do not emerge until 2.7Ma. Foraminiferal fragmentation counts indicate that carbonate preservation is not the primary process behind enhanced carbonate deposition during interglacials. Thus, we surmise that hydrography-related changes in biogenic opal and carbonate production in surface water best explain glacial–interglacial carbonate cycles beginning with significant NHG. Firm establishment of orbital-scale age control on the stratigraphically complete Site 1208 section now provides a platform for high-resolution paleoceanographic reconstruction of the relatively understudied North Pacific.