Whole rock geochemistry – major elements - from selected basalts dredged from seamounts in the south Tasman Sea during RV Investigator voyage IN2018_V08

XRF geochemical major and trace element data of whole rocks collected from submarine edifices in the southern Tasman Sea. Samples that did not show alteration were used for the analysis. Whole rocks were crushed in an agate mill and analysed at the University of Tasmania XRF Facilities. Instrument was a PANalytical Axios Advanced X-Ray Spectrometer. Major elements were analysed via 32mm fusion discs prepared at 1100 degrees C in 5%Au/95%Pt crucibles 0.500g sample, 4.500g 12-22 Flux (Lithium Tetraborate-Metaborate mix), 0.0606g LiNO3 for silicates. Platinum/5% gold moulds used for cooling. Sulphide bearing samples have a different mix with more LiNO3 as oxidising agent and the mix is pre-ignited at 700 degrees C for 10 minutes. Ore samples and ironstones use 12/22 flux and a higher flux/sample ratio. Dolomites and limestones need pure lithium tetraborate as a flux. Iodine vapour is used as a releasing agent to remove discs from the mould. For trace elements 32mm diameter pressed powder pills (10g, 3.5 tonnes/cm-2), Sample Binder PVP-MCCorrections for mass absorption are calculated using PANalytical Super-Q software with its Classic calibration model and alpha coefficients. In house inter-element corrections are also applied. PANalytical ProTrace and Compton scattering can also be used for many trace elements. For calibration, pure element oxide mixes in pure silica, along with International and Tasmanian reference rocks are used. Numerous checks of reference rocks and pure silica blanks are run with each program.