Major and minor element compositions of ocean island olivine and spinel

The dataset consists of elemental compositions determined for olivine and spinel from 15 ocean islands, including Azores, Austral, Balleny, Cape Verde, Crozet, Fernando de Noronha, Galapagos, Gough, Juan Fernandez, Marquesas, Réunion, Society, St. Helena, Trindade, and Tristan da Cunha. These samples were loaned from Sedgwick Museum, University of Cambridge and National History Museum, London, except the Galapagos samples provided by D. Geist and the Réunion (Piton de la Fournaise) samples provided by J. Maclennan. Elemental compositions determined for three secondary standards (San Carlos olivine, MongOl olivine, and NHNM164905 augite) are also presented in the dataset. The data were acquired using a Cameca SX100 electron microscope at the Department of Earth Sciences, University of Cambridge, in four sessions between June and November 2021. The elements analysed include Mg, Si, Fe, Al, Ca, P, Cr, Mn, and Ni in olivine, and Mg, Si, Fe, Al, Ca, Cr, Mn, and Ti in spinel. The data were used to calculate olivine crystallisation temperatures and mantle potential temperatures based on an olivine-spinel thermometer and modelling of mantle melting. The data for olivine and spinel are presented separately in two spreadsheets.