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1. Data report: refinement of calcareous nannofossil biostratigraphy from the late Oligocene to the Pleistocene, IODP Expedition 363 Hole U1490A

   https://doi.org/10.14379/iodp.proc.363.204.2021  

   Doyongan, Y.I.L.; Fernando, A.G.S. (February 2021, Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   An Oligocene to recent sedimentary sequence was recovered in Hole U1490A in the northern portion of the Eauripik Rise (western Pacific Ocean) during International Ocean Discovery Program Expedition 363. High-resolution sampling and moderate to good calcareous nannofossil preservation allowed us to adjust the depths for nannofossil events reported shipboard. This study identified 22 zonal boundary markers and 30 secondary calcareous nannofossil events. Because of better preservation of the calcareous nannofossils in the Pliocene–Pleistocene units, more calcareous nannofossil events were observed in that interval than in the older units. In the Miocene units, the discoasters and helicosphaerids (which are important zonal boundary markers) are poorly preserved (fragmented and recrystallized), making it difficult to identify nannofossil zones. In lieu of zonal boundary markers, secondary calcareous nannofossil events were used to refine the biostratigraphy in the Miocene interval. 

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2. Data report: calcareous nannofossils from the middle Miocene to Pleistocene, IODP Expedition 370 Site C0023

   https://doi.org/10.14379/iodp.proc.370.201.2018  

   Hagino, K. (April 2018, Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   International Ocean Discovery Program Expedition 370 recovered marine subsurface sediments from 189 to 1126 meters below seafloor (mbsf) at Site C0023, which was established on the Nankai Trough, off Muroto Peninsula, Japan. Biostratigraphic studies based on calcareous nannofossil assemblages revealed the ages of sediments are from the middle Miocene to Pleistocene. Samples from 1126.885 to 796.530 mbsf yielded Miocene taxa such as Coccolithus miopelagicus, Cyclicargolithus floridanus, Catinaster calyculus, and Discoaster quinqueramus. The interval 790.285–774.984 mbsf spans the late Miocene to the early Pliocene, as it corresponds to bioevents spanning from the last occurrence (LO) of D. quinqueramus to the first occurrence of Ceratolithus cristatus. Samples from 769.440 to 639.982 mbsf are referred to the Pliocene based on occurrences of C. cristatus, Reticulofenestra pseudoumbilicus (≥7 µm), and/or Discoaster surculus. Sediments from 630.440 to 190.483 mbsf are dated to the Pleistocene, as an interval above the LO of Discoaster pentaradiatus. Preservation of calcareous nannofossils is poor or moderate in the middle Miocene samples and moderate to good in the samples from the upper Miocene to Pleistocene. 

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3. Data report: calcareous nannofossils and lithologic constraints on the age model of IODP Site U1450, Expedition 354, Bengal Fan

   https://doi.org/10.14379/iodp.proc.354.203.2020  

   Lenard, S.J.P.; Cruz, J.; France-Lanord, C.; Lavé, J.; Reilly, B.T. (May 2020, Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   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. 

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4. Data report: Miocene planktonic foraminifers Dentoglobigerina and Globoquadrina from IODP Sites U1489 and U1490, Expedition 363

   https://doi.org/10.14379/iodp.proc.363.203.2020  

   Fayolle, F.; Wade, B.S. (November 2020, Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   International Ocean Discovery Program Expedition 363 Sites U1489 and U1490, located in the Western Pacific Warm Pool, contain diverse assemblages of planktonic foraminifers. We examined and imaged specimens of Miocene Dentoglobigerina and Globoquadrina to determine the presence or absence of spine holes and pustules in their wall texture. A total of 15 specimens were observed across six species, including Dentoglobigerina baroemoenensis, Dentoglobigerina binaiensis, Dentoglobigerina globosa, Dentoglobigerina globularis, Dentoglobigerina tripartita, and Globoquadrina dehiscens. Here we present scanning electron microscope and z-stacking light microscope images in three views, including illustrations of their wall texture. 

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5. Data report: late Pliocene planktonic foraminifer assemblages from IODP Holes U1443B, U1443C, and U1445A

   https://doi.org/10.14379/iodp.proc.353.201.2018  

   Robinson, M.M.; Dowsett, H.J. (November 2018, Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   Planktonic foraminifers are key to reconstructing the paleoceanography and monsoon history of the Bay of Bengal. We examined foraminifers from International Ocean Discovery Program Site U1443 on the Ninetyeast Ridge and Site U1445 in the northwest Bay of Bengal, documented the planktonic assemblages, and compared four measures of sample preservation. These samples contain typical late Pliocene assemblages, although the upper stratigraphic limits of Sphaeroidinellopsis seminulina and Dentoglobigerina altispira are more similar to those of the Atlantic Ocean than of the Pacific Ocean. Observations of sample fragmentation and test preservation are more useful than numerical calculations based on foraminifer abundances in describing sample dissolution and offer a consistent means to compare samples from different sites in the Bay of Bengal. 

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