This dataset comprises the geochemical and mineralogical analysis of six samples of massive sulphide deposit. Three samples were obtained from seafloor massive sulphide (SMS) systems obtained during RV Celtic Explorer cruise CE11009 (Mid-Atlantic Ridge 45° N, 2011) and RRS James Cook cruises JC082 (Mid-Cayman Spreading Centre, 2013) and JC138 (Mid-Atlantic Ridge at 26° N, 2016). Three samples were obtained from land-based volcanogenic massive sulphide (VMS) deposits on Wetar Island, Indonesia. It is thought these samples were obtained in 2002 at Kali Kuning and Lerokis Zones 4 and 5, but users should be aware there is little to no metadata about the Wetar Island sample origins. The sample analyses includes: (1) bulk geochemical analysis of sulphide samples by inductively coupled plasma mass spectrometry (ICP-MS) for bulk and effluent analysis and inductively coupled plasma orbital emission spectrometry (ICP-OES), (2) petrographic descriptions of samples by reflective microscopy, (3) geochemical analysis of seawater samples during experiments by ICP-MS, (4) mineralogical analyses (X-ray Diffraction) of sulphide samples, (5) mineralogical analyses by Scanning Electron Microscope and energy dispersive X-ray spectroscopy (SEM-EDS) on sulphide grains, (6) SEM backscattered electron (BSE) images of reacted sulphide grains, and (7) surface areas determined by Brunauuer-Emmett-Teller (BET) surface area analysis. All analyses were undertaken as part of a PhD project which aimed to enhance understanding of sulphide oxidation kinetics, the formation of Fe-oxyhydroxide from sulphide oxidation, its capacity to retain metals that would otherwise be lost to seawater in SMS systems, and the implications for potential seafloor mining operations. Analyses took place at the University of Southampton and the National Oceanography Centre Southampton, funded under the Natural Environment Research Council (NERC) project Ultramafic-hosted mineral Resource Assessment (ULTRA) grant, NE/S004068/1. This collection consists only of the data collected under the PhD project and not all data associated with the ULTRA project.

The iGlass project (using Inter-GLacials to Assess future Sea-level Scenarios) data set will comprise: acquisition of new relative sea-level data (sediments and microfossils - diatoms and foraminifera) from estuarine environments, speleothems (cave deposits), corals as well as chemical composition of marine plankton shells (foraminifera) contained in sediment cores, from around the world; palaeodata synthesis of interglacial sea level and climate; and modelling of isostatic, climate and sea-level changes and interactions during past interglacials. The iGlass consortium aims to better understand the processes of ice-sheet and sea-level response to climatic forcing using data from the recent geological past. The data will cover the time period between 427 and 115 thousand years before present covering Marine Isotope Stages (MIS) 5, 7, 9 and 11. The dataset currently includes the synthesis of high-latitude air and sea surface temperature from the last Interglacial MIS5 between 115 and 130 thousand years before present. Sediment coring and the analysis of microfossils within these, will acquire new sea-level data. There will be geophysical modelling of vertical land movements and gravitational effects, which cause deviations of regional sea level from the global mean trend. Investigation of climate/ice-sheet/sea-level interactions using both observations and modelling, to reveal the underlying processes. Coring will take place in Norfolk and the Red Sea and speleothems will be investigated in Bermuda. Data synthesis and some model output will concentrate on the high northern and southern latitudes; other model output will be global. iGlass is funded by the UK Natural Environment Research Council and comprises the following research institutions; University of Southampton, National Oceanography Centre (NOC), University of York, University of Oxford, University of Durham, University of Bristol, University of Reading, University of Cambridge and British Antarctic Survey (BAS). It also includes two academic partners; University of Ottawa and Australian National University and three the non-academic partners; UKCIP, Environment Agency and Willis Ltd. There are also external researchers based at Oregon State University and National Center for Atmospheric Research. Currently the synthesis of high-latitude air and sea surface temperature from the last Interglacial MIS5 and the synthesis of coral indicators of past sea-level change are available from BODC. Other data will be added in due course.

This dataset comprises a variety of sediment core data from the Semenov Hydrothermal Field region of the Mid-Atlantic Ridge, collected during RRS James Cook cruises JC224 (March - April 2022) and JC254 (October - November 2023). A total of 29 gravity cores, 9 mega-cores, and 25 push cores were successfully recovered. Analysis of the sediment core samples was conducted at the British Ocean Sediment Core Research Facility (BOSCORF), where the cores are held for long term storage, and included: imaging, spectrometry, geophysical and geochemical measurements of sediment and porewaters, radiocarbon dating, and stable isotope analysis. The main coring equipment used during both cruises was a gravity corer to collect sediment cores of up to 3 m in length. For JC224, a mega-core, with a USBL transponder attached to the frame, was used to obtain undisturbed cores from the upper 40 cm of the sediment surface. For JC254, push cores were also collected during several Remotely Operated Vehicle (ROV) dives using the Isis vehicle. The key objectives of the sediment coring were: (1) to reconstruct the history of the hydrothermal activity by dating plume fallout layers in the sedimentary record, and (2) to assess the role of the sediment cover in the preservation of seafloor massive sulphide (SMS) deposits in an ultra-slow spreading scenario. The data were collected as part of a PhD project funded under the Natural Environment Research Council (NERC) project Ultramafic-hosted mineral Resource Assessment (ULTRA) grant, NE/S004068/1. This collection consists only of the data collected under the PhD project and not all data associated with the ULTRA project.

The data set comprises a diverse collection of physical, chemical and biological measurements, encompassing well over 1000 parameters. There are data from over 1000 conductivity-temperature-depth (CTD)/rosette stations, over 440 core profiles, over 180 sediment trap samples, over 140 net hauls and much, much more. The primary study area was a box extending to the base of the slope from Vigo to Cap Finistere. However, data are included from both further offshore (filament tracking) and from the Portuguese Margin. Measurements were taken from November 1996 to October 1999 during 33 cruise legs, involving research vessels from seven nations. Data were collected using a variety of equipment and techniques, including expendable bathythermographs (XBTs), turbulence probes, CTDs and oceanographic undulators with auxiliary sensors. These hydrographic profiles were accompanied by net hauls, plankton recorder deployments, sediment cores and a comprehensive water sampling programmes during which a wide variety of chemical and biological parameters were measured. The station data were supplemented by underway measurements of oceanographic and meteorological properties. Results from production and phosphate uptake experiments are also included in the dataset, as are bathymetric data from multibeam (swath) surveys, coastal upwelling measurements and data from moored instruments and benthic landers. The dataset also includes imagery from satellites, seabed photography and X-ray photographs of core samples. The aim of the project was study biogeochemical processes at the shelf break and to quantify the fluxes of material between the shelf and the open ocean. The project brought together over 100 scientists from 40 research centres and universities throughout Europe. The British Oceanographic Data Centre (BODC) is assembling the data sets collected during OMEX II into its project database system and the data set is also available on CD-ROM.

The data set comprises a diverse collection of physical, chemical and biological measurements, encompassing over 1000 parameters. There are data from over 1650 conductivity-temperature-depth (CTD)/rosette stations, over 300 core profiles, over 370 sediment trap samples and much, much more. Most of this effort was directed at the region of the east Atlantic margin between La Chapelle Bank and the Goban Spur (between France and Ireland). In addition, there were two secondary areas of interest: the Norwegian Shelf Break just off Tromso and the Iberian Margin, either off Vigo or in the vicinity of the Tagus estuary. Measurements were collected from April 1993 until the end of December 1995 during 55 research cruise legs. Data were collected using a variety of equipment and techniques, including expendable bathythermography (XBTs), CTDs and oceanographic undulators with auxiliary sensors. These hydrographic profiles were accompanied by net hauls, plankton recorder deployments, sediment cores and comprehensive water and air sampling programmes during which a wide variety of chemical and biological parameters were measured. The station data were supplemented by underway measurements of oceanographic and meteorological properties. Results from production and trace metal experiments are also included in the dataset, as are bathymetric data from the British Oceanographic Data Centre (BODC) GEBCO digital Atlas, air-sea flux measurements and data from moored instruments and benthic landers that were deployed for periods from a few weeks to a year. The dataset also includes imagery from satellites, water column and seabed photography, scanning electron micrographs and X-ray photographs. FORTRAN source code for biogeochemical models developed during OMEX I is also included. The aim of the project was to study biogeochemical processes at the shelf break and to quantify the fluxes of material between the shelf and the open ocean. OMEX I involved scientists from 30 institutions in 10 countries. BODC is assembling the data sets collected during OMEX I into its database system and the data are also available on CD-ROM.