411f95d1-f5da-584a-e063-3050940a3e2b 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 2026-03-17 UK GEMINI 2.3 http://data.bgs.ac.uk/id/dataHolding/13608544 Major element, trace element and Nd isotopes of cumulate plagioclase and clinopyroxene in lower crustal gabbros from Hess Deep oceanic crust, East Pacific Rise, with elemental maps of all studied samples 2025-10-10 creation http://data.bgs.ac.uk/id/dataHolding/13608544 We collected major element, trace element and Nd isotopes of cumulate plagioclase and clinopyroxene in lower crustal gabbros from Hess Deep oceanic crust (~2°15'N, 101°30'W) to investigate the Nd isotopic heterogeneity of melts delivered to a complete section of Hess Deep oceanic crust, accreted at the fast-spreading (133 mm/yr) East Pacific Rise (EPR). These data are presented in Cooper et al. (2025) (https://doi.org/10.1130/G52872.1). Elemental maps of 58 samples were initially obtained prior to selecting a subset of 25 samples for in-situ microanalysis. We targeted the Nd isotope record of cumulate plagioclase and clinopyroxene from lower crustal gabbro samples, representing early crystallisation products of melts delivered to the crust. These samples were collected in several expeditions: Ocean Drilling Program (ODP) Leg 147; RSS James Cook cruise JC21; Integrated Ocean Drilling Program (IODP) Expedition 345 (Site U). Combined, these studies provide the most complete composite section of fast-spreading EPR crust to date (stratigraphic depth of 4350 m to 25 m). In our study, we selected 25 samples for in situ Nd isotope microanalysis, covering the range of mineralogy and textural diversity, and over the full stratigraphic depth. For a comparison to local MORB compositions, we selected a set of 13 upper-crustal sheeted dikes collected on the RSS James Cook cruise JC21. Our data reveal that the mantle is heterogeneous at the scale of melt extraction, and the crystal record from the lower crust shows greater 143Nd/144Nd heterogeneity than the overlying MORB. Hence, Pacific MORBs do not reflect the full heterogeneity of their mantle source, and some aggregation of melts occurs within the crust. Data was collected between 2020 and 2023 by George Cooper, Johan Lissenberg and Max Jansen at Cardiff University, UK, as part of NERC Grant NE/T000317/1:HiDe: A Highly Heterogeneous Depleted Upper Mantle? Mineral isotopic analyses were performed on a Thermo Scientific TRITON Plus at the Vrije Universiteit in Amsterdam. The long-term average and reproducibility (2019–2022) for the JNdi-1 standard is 0.512094 ± 0.000011 2 SD (standard deviation; n = 28) with 1011Ω resistors (used for clinopyroxene) and 0.512105 ± 0.000044 2 SD (n = 45) with four 1013Ω resistors (used for plagioclase). Full methodology can be found within the supplemental Material of Cooper et al. (2025) at https://doi.org/10.1130/GEOL.S.28485770 The DOI is a supplement to https://doi.org/10.1130/G52872.1 Methodology: https://gsapubs.figshare.com/articles/journal_contribution/Supplemental_Material_Crustal_versus_mantle-level_aggregation_of_heterogeneous_melts_at_mid-ocean_ridges/28485770?file=52665137 Johan Lissenberg University of Cardiff School of Earth and Environmental Sciences, Cardiff University Main building, Park Place Cardiff CF10 3AT not available originator Marc-Alban Millet University of Cardiff not available originator George Cooper University of Cardiff not available originator Janne M. Koorneef Vrije Universiteit not available originator Enquiries British Geological Survey United Kingdom not available distributor Enquiries British Geological Survey United Kingdom not available distributor Enquiries British Geological Survey not available pointOfContact Enquiries British Geological Survey United Kingdom not available pointOfContact notApplicable https://resources.bgs.ac.uk/images/geonetworkThumbs/411f95d1-f5da-584a-e063-3050940a3e2b.png Geology GEMET - INSPIRE themes, version 1.0 2008-06-01 publication MORB Major element analysis Neodymium isotopes Heterogeneity Plagioclase Gabbro Oceanic crust Clinopyroxene Trace elements 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]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused. Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]" English geoscientificInformation 2020-01-01 2023-01-01 Microsoft Excel (XLSX) witheld Comma-separated values (CSV) witheld Enquiries British Geological Survey United Kingdom not available distributor Enquiries British Geological Survey United Kingdom not available distributor https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item190265 WWW:DOWNLOAD-1.0-http--download Data download https://doi.org/10.5285/7cac54fd-7530-48f6-bb1e-3c103d9e4b23 WWW:LINK-1.0-http--related Citation Information - Digital Object Identifier (DOI) Cooper, G. F., Lissenberg, C. J., Koorneef, J. M., Jansen, M. N., Millet, M.-A. (2025). Major element, trace element and Nd isotopes of cumulate plagioclase and clinopyroxene in lower crustal gabbros from Hess Deep oceanic crust, East Pacific Rise, with elemental maps of all studied samples. NERC EDS National Geoscience Data Centre. (Dataset). https://doi.org/10.5285/7cac54fd-7530-48f6-bb1e-3c103d9e4b23 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 Elemental maps of all studied samples were carried out on a Zeiss Sigma HD field emission gun scanning electron microscope (SEM) at Cardiff University, UK. Mineral trace element concentrations were measured by laser ablation–inductively coupled plasma–mass spectrometry (LA-ICPMS) (Applied Spectra Inc. RESOlution S-155 laser coupled to an Agilent 8900 ICP-QQQ). Nd concentrations were used to predetermine the sample volume needed to be recovered from micromilling. Typical Plagioclase and Clinopyroxene cores from each sample were drilled using a New Wave™ Research MicroMill. Milled powders were digested in HF and HNO3 prior to Nd separation by column chemistry. Mineral Isotopic analyses were performed on a Thermo Scientific TRITON Plus at the Vrije Universiteit, and whole-rock dike samples were measured on a Nu plasma II multicollector ICP-MS at Cardiff University.