Geochemistry of basalts from ODP Hole 113-690C ...

• Main Authors: Schandl, Eva S, Gorton, Michael P, Wicks, F J
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1990
• Subjects: Drilling/drill rig; Leg113; Joides Resolution; Ocean Drilling Program ODP; Antarc*; Antarctica; Weddell Sea; Ocean Island
• Online Access: https://dx.doi.org/10.1594/pangaea.753879; https://doi.pangaea.de/10.1594/PANGAEA.753879

Basalts from Maud Rise, Weddell Sea, are vesicular and olivine-phyric. Major, trace, and rare earth element concentrations are similar to those of alkali basalts from ocean islands and seamounts. The rocks are low in MgO, Cr, Ni, and Sc, and high in TiO2, K2O, P2O5, Zr, and LREE contents. The abundance of "primary" biotite and apatite in the matrix indicates the melting of a hydrous mantle. Prevalence of olivine and absence of plagioclase in the rocks suggests that the volatile in the melt was an H2O-CO2 mixture, where H2O was <0.5.Mantle derived xenocrysts in the basalt include corroded orthopyroxene, chromite, apatite, and olivine. Olivine (Fo90) is too magnesian to be in equilibrium with the basalts, as they contain only 5-6 wt% MgO.Based on the presence of mantle xenocrysts, the high concentration of incompatible elements, the spatial and chemical affinity with other ocean island basalts from the area, and the relative age of the basalt (overlain by late Campanian sediments), it is suggested that Maud ... : Supplement to: Schandl, Eva S; Gorton, Michael P; Wicks, F J (1990): Mineralogy and geochemistry of alkali basalts from Maud Rise, Weddell Sea, Antarctica. In: Barker, PF; Kennett, JP; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 113, 5-14 ...