This dataset contains the semiquantitative data relative to the calcareous nannofossil assemblages from a subset of 26 samples from ODP Site 1053 core 8, Section 5. Samples span 74.54 to 75.20 m in composite depth, with a sample resolution that ranges from 1 to 10 cm. Data was collected From January to April 2023 and span a 1 M.y. long late Eocene Interval, Priabonian in age, that corresponds to the CNE19 nannofossil zone of the Priabonian (ca. 36 Ma; Agnini et al., 2014; Raffi et al., 2016). The samples from which the calcareous nannofossil assemblages were obtained were collected from ODP Site 1053, in the Blake Nose, NW Atlantic Ocean. This dataset has a regional resolution. Following previous results on bulk carbon and Oxygen stable isotopes, data was collected to further investigate the Blake Nose's regional paleoceanography during the Late Eocene. Nannofossil smear slides were prepared and examined using an Olympus BX51 polarizing microscope at the MARUM – Center for Marine Environmental Sciences (University of Bremen). Biostratigraphic analyses were conducted at low (600x) magnification along two long transects of each slide to ensure that rare, biostratigraphically significant taxa were not overlooked. For qualitative assemblage analyses, ten fields of view (FOV) from a representative area of each slide were examined at higher (1000x) magnification. The individual abundance of each species within a sample was then estimated as follows:
C: At least one specimen present in every FOV
Fr: One specimen present in 6 to 9 of the FOV
F: One specimen present in 2 to 5 of the FOV
R: Specimen only present in one of the FOV
VR: 5 or less specimens observed within the whole sample (used for the taxa that were only observed while conducting biostratigraphic analyses).
