Rock samples from Marie Byrd Seamounts were dredged for the first time during R/V Polarstern expedi­tion ANT-XXXIII/4 in spring 2006. The seamounts form a group of 8 submarine volcanic edifices located in the southern Amundsen Sea between 68°-72°S and 112°-132°W off the shelf of Marie Byrd Land. Basalts dredged at the flanks of the Hubert-Miller-Seamount belong to the alkali basalt – trachybasalt diffe­rentiation series. Cumulates including Ti-augites are proof for an additional more Si-undersaturated phase of magmatism, xenocrysts of oligoclase indicate shallow magma plum­bing of higher degrees of differentiation. Igneous clasts with sub-greenshist metamorphic overprint are indications for flank collapses. However, samples of yet uncertain origin are (1) Si-saturated coarse crystalline igneous clasts (dykes including lamprophyric texture) some with metamorphic overprint and (2) quartz sandstones and litharenites with grains of defor­med quartz as well as light mica which require continental crust as source rocks.