24837f60-a965-206c-e063-0937940a75a1 English nonGeographicDataset non geographic dataset British Geological Survey +44 115 936 3100 Environmental Science Centre,Keyworth NOTTINGHAM NOTTINGHAMSHIRE NG12 5GG United Kingdom enquiries@bgs.ac.uk pointOfContact 2026-05-06 UK GEMINI 2.3 http://data.bgs.ac.uk/id/dataHolding/13608286 Late Eocene microspherule count and foraminifera multispecies oxygen and carbon stable isotope data from DSDP Site 94 2024-10-13 creation http://data.bgs.ac.uk/id/dataHolding/13608286 Twenty-six 10 cm3 samples from DSDP (Deep Sea Drilling Project) Site 94, Core 15, sections 3 and 4 were examined at 10 cm-intervals (417.84-415.01 meters below seafloor [mbsf]). The sedimentary material was soaked in distilled water and washed under running water through a 63 µm sieve and oven dried at <40 degrees C. Samples were then re-washed and dried using the same method. Foraminifera are abundant and recystallised. Calcite precipitation is observed on microspherules in some samples. For each sample, a total of three foraminiferal species that correspond to different ecological habitats were selected for isotope analysis. Specimens of Pseudohastigerina micra and P. naguewichiensis were selected from the 125-250 µm size fraction and Turborotalia cocoaensis, and Cibicidoides eocaenus were selected from the >250 µm size fraction. Specimens that had infilling or showed heavy calcification were avoided. All foraminifera were ultrasonicated for 2 seconds prior to isotopic analyses. To track the number of impact microspherules across the sampled interval, we performed our own microspherules count from the >125 micron size fraction. Microtektites have not been distinguished from microkrystites in this study and thus all recovered spherules should be considered under the broader category of microspherules (both microtektites and crystalline-bearing microkrystites). We recovered a total of 4999 microspherules from the 26 samples. Microspherules are usually <1 mm in size, and occur primarily spherical, although ellipsoid, teardrop and dumbbell forms and fragments have also been found. In most samples the microspherules count is low <50 microspherules. We found a high abundance (>50 microspherules/10 cm3) between samples 15R/3/135-137 cm and 15R/3/89-91 cm (416.36 to 415.90 mbsf). Our peak concentration of microspherules at 15R/3/109-111 cm (416.10 mbsf), where 3395 microspherules were recovered, coincides with the younger of the two late Eocene impacts i.e., the North America microtektite horizon associated with the Chesapeake Bay impact. Professor Bridget Wade University College London Professor of Micropalaeontology, Department of Earth Sciences Gower Street London WC1E 6BT not available originator Natalie Cheng University College London not available originator Enquiries British Geological Survey United Kingdom not available distributor Enquiries British Geological Survey United Kingdom not available pointOfContact notApplicable https://resources.bgs.ac.uk/images/geonetworkThumbs/24837f60-a965-206c-e063-0937940a75a1.png Geology GEMET - INSPIRE themes, version 1.0 2008-06-01 publication Tektites Eocene Foraminifera Stable isotopes BGS Thesaurus of Geosciences 2022 revision NGDC Deposited Data Citable Data dataCentre NERC_DDC otherRestrictions licenceOGL Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]" otherRestrictions The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. 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Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]" English geoscientificInformation 2018-01-25 2024-04-03 Microsoft Excel witheld Enquiries British Geological Survey United Kingdom not available distributor https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item186339 WWW:DOWNLOAD-1.0-http--download Data download https://doi.org/10.5285/a0b6a773-1d18-4ced-a57e-06f8d67428b9 WWW:LINK-1.0-http--related Citation Information - Digital Object Identifier (DOI) Wade, B., Cheng, N. (202). Late Eocene microspherule count and foraminifera multispecies oxygen and carbon stable isotope data from DSDP Site 94. NERC EDS National Geoscience Data Centre. (Dataset). https://doi.org/10.5285/a0b6a773-1d18-4ced-a57e-06f8d67428b9 information nonGeographicDataset non geographic dataset INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology 2011 publication See the referenced specification false Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 publication See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF false Foraminifera were analysed at the Bloomsbury Environmental Isotope Facility (BEIF) at University College London on a Thermo DeltaPLUS XP continuous-flow Gas-ratio mass spectrometer attached to a Thermo Gas Bench II device. Precision of all internal (BDH) and external standards (NBS-19) is ±0.06‰ for δ13C and ±0.10‰ for δ18O for the planktonic foraminiferal samples, and ±0.02‰ for δ13C and ±0.06‰ for δ18O for the benthic foraminiferal samples. All isotope values are normalised to NBS-19 and reported in per mil in the δ notation relative to the Vienna Pee Dee Belemnite (VPDB).