Elastic thickness data for Tasmantid Seamounts determined from gravity modelling. Published paper, Richards, Fred & Kalnins, Lara & Watts, A. & Cohen, Benjamin & Beaman, Robin. (2018). The Morphology of the Tasmantid Seamounts: Interactions Between Tectonic Inheritance and Magmatic Evolution. Geochemistry, Geophysics, Geosystems. 10.1029/2018GC007821.

Zircon U-Pb data are presented for six plutonic rocks recovered from the Pacific oceanic crust (IODP Hole 1256D). These data constrain the age of the section, as well as the duration of crustal accretion. The data cover the bulk of the plutonic section recovered and were generated during post-cruise research for IODP Expedition 335 (2011-2013; PI Lissenberg). Data collection was done at the NERC Isotope Geosciences Laboratories at the British geological Survey. NERC Isotope Geosciences Facilities award IP-1276-1111. This work resulted from participation in IODP Expedition 335, NERC grant NE/J005592/1

The data set presents major and trace element geochemical data obtained from ICP-MS measurements on micro-drilled subsamples of ferromanganese (Fe-Mn) crusts from Tropic Seamount, north-east Atlantic Ocean. The data represent detailed stratigraphic analysis of Fe-Mn crust samples 078_019 and 085_004. These samples were collected at 3100 and 1100 meters beneath sea level, respectively, during the JC142 expedition of the RRS James Cook for the MarineE-Tech project in 2016.

Two published papers: Modelling the Lost City Hydrothermal Field: Influence of topography and Permeability structure. https://doi.org/10.1111/gfl.12151: and Rapid generation of reaction permeability in the roots of black smoker systems, Troodos ophiolite Cyprus. https://doi.org/10.1111/gfl.12117

The dataset includes abundances of phosphorus redox species (phosphate, phosphite, pyrophosphate) and metal abundances for a collection of mafic and ultramafic rocks. These include peridotites, komatiites and basalts from a variety of locations and ages. The results show that reduced and polymerized phosphorus is present in unaltered mafic and ultramafic rocks, in addition to phosphate. Therefore, oceanic crust can serve as a source of reactive phosphorus species.

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

Physical properties of four serpentinite and four gabbro samples acquired respectively at the Southern Wall (IODP leg 357) and at the Central Dome (IODP leg 304-305) of the Atlantis Massif have been measured and analysed in the frame of a NERC UK-IODP moratorium research. The physical property measurements included simultaneous ultra-sonic wave velocities (compressional and shear wave velocities), attenuation, electrical resistivity and permeability under increasing and decreasing effective pressure ranging between 5 and 45 Mpa. Measurements were carried out using the experimental physical property measurement rig of the rock Physics laboratory of the National Oceanography Centre, Southampton, UK. The porosity and the density of the samples were estimated using their wet dry weight difference and the volume of the samples, under atmospheric pressure and room temperature. The aim of this research project was to learn about the physical properties of oceanic lower crustal and upper-mantle rocks and to find a geophysical method that would allow to distinguish between these rocks, remotely. The dataset has been acquired and interpreted by a science party including researchers from the University of Southampton and the National Oceanography Centre. The ultrasonic wave velocities, attenuation and the electrical resistivity for each sample and for each effective pressure (increasing from 5 to 45 with an interval of 10 MPa and decreasing from 45 to 5 with an interval of 20 MPa) are reported in this dataset. Permeability measurements could have been carried out only on 6 samples for which the permeability was high enough to be measured with the experimental rig.

Zircon U-Pb isotope data are presented for eight plutonic rocks from the Masirah ophiolite and one plutonic rock from the Ra's Madrakah ophiolite (south east Oman). These data constrain the age of formation of the two ophiolite nappes exposed on Masirah Island (early Cretaceous), whereas two intrusions with younger ages (late Cretaceous) overlap with the proposed emplacement age of the ophiolite. The data cover two sites in the Masirah Lower Nappe, two sites in the Masirah Upper Nappe (on Masirah Island, off the SE coast of Oman) and one site on Ra's Madrakah (on the mainland of Oman). The interpretation and discussion of these data form part of a manuscript submitted to Geochemistry, Geophysics, Geosystems. Data collection was done using chemical abrasion isotope dilution thermal ionisation mass spectrometry (CA-ID-TIMS) at the NERC Isotope Geosciences Laboratories at the British geological Survey, supported by NERC Isotope Geosciences Facilities award IP-1919-0619. This work resulted from a PhD project funded by NERC GW4+ DTP grant NE/L002434/1.

Data produced from NERC Grant NE/L000059/1 - IODP Exp 335 report which is open access and includes all the observations and other data generated on the Expedition. http://publications.iodp.org/proceedings/335/335toc.htm