Many tephra layers were identified in sediment cores drilled during IODP Expedition 350. Here, 1092 glass shards from 76 tephra occurrences (layer or patch) were analysed using electron probe microanalyses (EPMA). Data are not averaged, nor normalised. Geochemistry data were collected for: SiO2, TiO2, Al2O3, Cr2O3, FeO, MnO, MgO, CaO, Na2O, K2O, P2O5, SO3, Cl and O. Secondary standard data are given, as well as beam setup conditions. The data were obtained using the instruments at the University of Bristol, over two sessions during October and November 2014.

Microstructural data for rocks in the Shiant Isles Main Sill, presented as a function of stratigraphic height in the sill. The data were published: Holness et al. (2017) Contributions to Mineralogy and Petrology, 172:7. OI 10.1007/s00410-016-1325-x

Mean grain size data in the sortable silt fraction (10-63 um) from 0- 8 meters composite depth in Ocean Drilling Program (ODP) site 980. Ocean Drilling Program (ODP) Site 980 was drilled in July 1995 in the North Atlantic Ocean, on the Feni Drift, off the eastern edge of the Rockall Plateau at 55.49°N, 14.70°W. Hole 980A Position: 55°29.087'N, 14°42.134'W. Hole 980B Position: 55°29.094'N, 14°42.137'W.

120 samples of 57 tephra layers identified at IODP Expedition 350 sites (U1436 and U1437) were used in grain size analysis. Some layers have one grain size measurement, others have multiple measurements throughout the tephra layer.

The BGS Seabed Sediments 250k dataset is vector data is vector data which reflects the distribution of seabed substrate types of the UK and some of its adjacent waters at 1:250,000 scale. This comprehensive product provides a digital compilation of the paper maps published by BGS at the same scale, as well as, additional re-interpretations from regional geological studies. The seabed is commonly covered by sediments that form a veneer or thicker superficial layer of unconsolidated material above the bedrock. These sediments are classified based on their grain size reflecting the environment in which were deposited. This information is important to a range of stakeholders, including marine habitat mappers, marine spatial planners, offshore industries (in particular, the dredging and aggregate industries). This dataset was primarily based on seabed grab samples of the top 0.1 m, combined with cores, dredge samples and sidescan sonar acquired during mapping surveys since the early 1970s. The variations in data density will be reflected in the detail of the mapping.