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.