Mantle reservoirs and mafic magmatism associated with the break-up of Gondwana : the Balleny Plume and the Australian-Antarctic discordance : U-Pb zircon dating of a Proterozoic mafic dyke swarm in the Vestfold Hills, East Antarctica ...

• Main Author: Lanyon, R
• Format: Thesis
• Language: unknown
• Published: University Of Tasmania 2023
• Subjects: Antarctic; Australian-Antarctic Discordance; East Antarctica; Vestfold; Vestfold Hills; Antarc*; Antarctica; Ocean Island
• Online Access: https://dx.doi.org/10.25959/23232377; https://figshare.utas.edu.au/articles/thesis/Mantle_reservoirs_and_mafic_magmatism_associated_with_the_break-up_of_Gondwana_the_Balleny_Plume_and_the_Australian-Antarctic_discordance_U-Pb_zircon_dating_of_a_Proterozoic_mafic_dyke_swarm_in_the_Vestfold_Hills_East_Antarctica/23232377

Part 1: Within the recent literature, the isotopic heterogeneity of ocean island basalts (OIB) is generally ascribed to mixing between any two or more of four isotopically distinct mantle end-member components - DMM, HIMU, EMI and EMU - the origin and precise location of which are still the subject of much debate. An attempt is made here to constrain the geochemical characteristics of these end-member components using literature-derived endmember OIB data. This has confirmed the presence of consistent trace element differences and also suggested certain major element distinctions, which are interpreted to reflect diverse end-member mantle source compositions rather than differences in the pressure and temperature of melting involved in OIB production. EMI basalts, which extend to the lowest \\(^{143}\\)Nd/\\(^{144}\\)Nd values of all OIB, were found to possess the most distinctive major element characteristics, the latter evident as higher SiO\\(_2\\) and lower FeO*, CaO, TiO\\(_2\\), P\\(_2\\)O\\(_5\\) and ...