Petrology of ultramafic lamprophyres from the Beaver Lake area of Eastern Antarctica and their relation to the breakup of Gondwanaland

• Published in: Mineralogy and Petrology
• Main Authors: Melzer, S., Andronikov, A. V., Foley, S. F.
• Other Authors: Department of Geological Sciences, University of Michigan, Ann Arbor, Mi, U.S.A., US, Projektbereich 4.1, Geoforschungszentrum Potsdam, Potsdam, Germany, DE, Institut für Geologische Wissenschaften, Universität Greifswald, Greifswald, Germany, DE, Ann Arbor
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer-Verlag; Springer-Verlag Wien 2002
• Subjects: Legacy; Geology and Earth Sciences; Chemistry; Science; Antarctic; Beaver Lake; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/2027.42/42462; https://doi.org/10.1007/s007100200011

Mesozoic melilite-bearing ultramafic lamprophyres are developed as sill, dyke and plug-like intrusive bodies in the East Antarctic Beaver Lake area. They consist of varying amounts of olivine, melilite, phlogopite, nepheline, titanomagnetite and perovskite as major phases, accompanied by minor amounts of apatite, carbonate, spinel, glass and, rarely, monticellite. The rocks are mineralogically and geochemically broadly similar to olivine melilitites, differing in higher CO 2 and modal phlogopite and carbonate contents. The ultramafic lamprophyres are MgO-rich (13.4–20.5 wt%) and SiO 2 -poor (32.8–37.2 wt%), indicative of a near-primary nature. Major and trace element features are consistent with minor fractionation of olivine and Cr-spinel from melts originating at depths of 130–140 km. Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/42462/1/710-74-2-4-361_20740361.pdf