Differentiationsgeschichte der Vulkanite der Marie Byrd Seamounts, Amundsen See, Südwestpazifik

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Basalts dredges at the flanks of the Hubert-MilIer-Seamount in the Marie-Byrd-Seamount volcanic field belong to the alkali basalt - trachybasalt differentiation series. Samples of higher crystallinity (dykes) and basalt-andesitic composition are proof for an igneous phase of higher si-saturation, cumulates including Ti-augites for an additional Si-undersaturated phase of magmatism. Xenocrystals of oligoclase indicate shallow magma plumbing of higher degrees of differentiation. Igneous clasts with greenshist metamorphic overprint are indiactions for flank collapses in order to expose these rocks from the volcanoes interior. Quartz sandstones with deformed quartz grains as major component and additional light mica clasts require continental crust as source rocks. The analyses will be extended to include the samples from all seamounts successfully dredged for igneous rocks. The discussion of the own analytical results, the combined interpretation including the data from the partner project as well as possibly resulting additional analyses will be main aspects.