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International Ocean Discovery Program (IODP) Expedition 354 Site U1450 was drilled at the center of a transect of 7 sites across the Bengal Fan at 8°N where long-term accumulation rates are highest. Site U1450 primarily consists of sandy and silty-sandy turbidites deposited at a rate higher than 20 cm/ky. During periods when the depocenter shifted away from Site U1450, calcareous clay hemipelagic sediment was deposited at lower accumulation rates around 1–2 cm/ky. Dating of the lower Pleistocene and Pliocene sequences is hindered by the scarcity of microfossils in turbidites and the restriction of paleomagnetic data to the upper 190 m. This report presents the identification of new calcareous nannofossils collected from hemipelagic and turbiditic intervals between 218 and 687 m core depth below seafloor, Method A (CSF-A). These data are consolidated in a statistical age model that is constrained with ranges of plausible accumulation rates for the distinct lithologies. The age probability model ranges from 1.2 to 7.3 Ma for depths from 175.8 to 812.0 m CSF-A. Depending on constraints, 2σ uncertainties are around ±0.2 and 0.4 Ma. 

International Ocean Discovery Program (IODP) Expedition 354 Site U1451 was drilled as the easternmost of seven sites forming a transect across the Bengal Fan at 8°N. Site U1451 recovered the oldest Bengal Fan sediments of the expedition, providing a long sedimentary record and valuable chronostratigraphic constraints on seismic imaging. Two cores recovered from Hole U1451A, Cores 23H and 24H, had uninterpretable archive-half remanent magnetizations measured on ship, despite having a calcareous clay lithology that was generally suitable for magnetostratigraphy in middle Pleistocene sediments. Shipboard biostratigraphy places these cores around the Pliocene/Pleistocene boundary. Paleomagnetic measurements of discrete subsamples, reported here, indicate that both Cores 23H and 24H contain no magnetic reversals, implying each core was deposited during a single polarity chron. These results suggest, based on sedimentation rate estimates, that the Gauss–Matuyama reversal and the Pliocene/Pleistocene boundary in Hole U1451A is located between the base of Core 23H and top of Core 24H (129.54–131.33 m CSF-A), although this needs to be confirmed by postexpedition biostratigraphic studies.