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Rigil Guyot: Hole U1373A

Despite pelagic sediment observed during seafloor observation before spudding the hole, almost none was recovered. The very small amount of material in the core catcher is assumed to have settled out from the seawater in the core liner and likely represents the unsampled oozy sediment observed during seafloor observation. The assemblage contains Neogene background species Helicosphaera carteri and Calcidiscus leptoporus. Common species include small Gephyrocapsa and P. lacunosa. Rare specimens of Gephyrocapsa caribbeanica (>4 µm) were also observed, the first occurrence of which marks the base of Zone CN13. Based on the presence of G. caribbeanica (>4 µm) and P. lacunosa, as well as the disturbed nature of the recovered sediment, a range of Zones CN13–CN14 is assigned to this sediment.

Additional samples from the volcanic breccias and conglomerates are barren of nannofossils with the exception Sample 330-U1373A-1R-3, 14–16 cm, which contains an assemblage of long-ranging taxa (Table T1); however, the continued presence of P. lacunosa and small Gephyrocapsa and absence of discoasters suggests a similar zonal assignment of Zones CN13–CN14 (early Pleistocene).