Université de Neuchâtel

Pyroxenite xenoliths from Marsabit (Northern Kenya): evidence for different magmatic events in the lithospheric mantle and interaction between peridotite and pyroxenite

Kaeser, Benjamin ; Olker, Bettina ; Kalt, Angelika ; Altherr, Rainer ; Pettke, Thomas

In: Contributions to Mineralogy and Petrology, 2009, vol. 157, no. 4, p. 453-472

Garnet-bearing and garnet-free pyroxenite xenoliths from Quaternary basanites of Marsabit, northern Kenya, were analysed for microstructures and mineral compositions (major and trace elements) to constrain the thermal and compositional evolution of the lithospheric mantle in this region. Garnet-bearing rocks are amphibole-bearing websterite with ~5–10 vol% orthopyroxene. Clinopyroxene is...

Université de Neuchâtel

Li, Be, and B abundances in minerals of peridotite xenoliths from Marsabit (Kenya): Disequilibrium processes and implications for subduction zone signatures

Kaeser, Benjamin ; Kalt, Angelika ; Ludwig, Thomas

In: Geochemistry Geophysics Geosystems (G3), 2007, vol. 8, no. 9, p. 1-25

The light elements Li, Be, and B have been analyzed in situ in minerals from three groups of peridotite xenoliths hosted in Quaternary basanites from the Marsabit volcanic field (northern Kenya). Group I and II are fertile lherzolites that experienced deformation, decompression, and cooling in the context of Mesozoic rifting (Group I), followed by heating, static recrystallization, and associated...