Description: The presence and high abundances of the benthic foraminiferal group "elevated epifauna" has been proposed as indicator of the existence of Mediterranean Outflow Water (MOW) in the Gulf of Cadiz. Here we intend to use this potential proxy to reconstruct MOW in the early Pliocene at the Integrated Ocean Drilling Program (IODP) Hole U1387C. Cibicides lobatulus, Planulina ariminensis and Cibicides refulgens were found at this site, but high abundances of C. lobatulus and C. refulgens coincide with increases of shelf taxa and grain size, related to episodes of downslope transport. This issue calls into question the applicability of these species as MOW proxies. The present study therefore reassesses the role of these three elevated epifaunal species by means of stable isotope analyses (d18O, d13C) by contrasting their isotopic signature with that of shelf dwellers and deep-water taxa from Pliocene and Recent sediments from the Gulf of Cadiz and the western Iberian margin. Since foraminiferal calcite does not always precipitate in equilibrium with seawater, substantial efforts have been taken in order to determine species-specific offset values and to correct the isotopic signature for vital effects. Our corrected results demonstrate that C. lobatulus and C. refulgens are isotopically similar to the shelf dwellers in the Pliocene data-set, eliminating them as MOW indicators. Recent samples from the Gulf of Cadiz and the western Portugal shelf corroborate the wide bathymetric range of C. lobatulus from the shelf to the slope. Our results thus warrant for caution when considering C. lobatulus and C. refulgens as indicators of bottom current strength in unstable slope settings, particularly when co-occurring with allochthonous shelf dwellers. In contrast, P. ariminensis shows a signature close to deep-water taxa, corroborating its reliability as indicator of MOW.

Description: This dataset contains nannofossil assemblage and planktonic foraminifera assemblage data, the total encountered abundance of diatoms from ODP Site 722B. D/V JOIDES Resolution carried out drilling of ODP Site 722 as part of ODP Leg 117 between the 6th and 8th of September 1989. The samples used for data analysis presented in this entry were sampled from drill cores cored by XCB (see Shipboard Scientific Party, 1989; doi:10.2973/odp.proc.ir.117.107.1989). Sampling was conducted in the Kochi Core Center (KCC) in 2018. The data in this submission was generated to conduct research into upwelling and nutrient flux changes in the Oman Margin Upwelling Zone, details on data acquisition and hypothesis can be found in the associated publication. Nannofossil data was generated at JAMSTEC, Yokosuka, Japan, in April 2019 on an Olympus X52 polarizing light microscope under 1000x magnification. Calculation of total abundances of nannofossil and diatom and the sum of all siliceous fragments (including diatoms, radiolarian fragments and silicoflagellates) are given as numbers per gram (#/g) of dry bulk sediment following the methodology of Bordiga et al. (2015; doi:10.1016/j.revmic.2015.05.002). The dataset further provides sample-specific bulk accumulation rates based on the interpolated bulk density data based on shipboard moisture and density (MAD) data present in the ODP Site 722 Site Report of ODP Leg 117 (Shipboard Scientific Party, 1989; doi:10.2973/odp.proc.ir.117.107.1989), allowing for calculating calcareous nannofossil, diatom and planktonic foraminifer fluxes. Planktonic foraminifera assemblage data was generated at the University of Graz using a Zeiss V8 stereo microscope in 2019. Samples were sieved using a standard sieve set and picked from the size factions 〈500 µm, 500 - 250 µm and 250 - 125 µm. Foraminifer assemblage data is provided as specimens per g of sediment (#/g) and percentage data (%). The percentage data of foraminifera assemblages also contains information on the habitat of the identified planktonic foraminifera taxa to reproduce the ecological grouping of the taxa as applied in Auer et al. (pre-print 2023; doi:10.5194/cp-2023-14). The age model of all provided datasets is based on Bialik et al. (2020; doi:10.1029/2019pa003762).