Mineralogy, chemistry and spatial distribution of phyllomanganates, found in abundance at the bottom of thick Ni-laterite deposits, were established on dislocated vein-infillings showing banded and fibrous patterns (i.e. colloforms with rows of tiny boxwor ...
This study, which complements a first mineralogical work, presents detailed petrographic and chemical data on the sequences of clay infillings commonly found in serpentine veins of reactivated faults from the New Caledonian peridotite formation. Chemical t ...
Explosive silicic volcanism is driven by gas overpressure in systems that are inefficient at outgassing. The zone at the margin of a volcanic conduit-thought to play an important role in the outgassing of magma and therefore pore pressure changes and explo ...
Double perovskite oxides A(2)BB'O-6 combining 3d and 4d or 5d transition metal ions at the B and B' sites feature a variety of magnetic and magneto-electric properties. Targeting Ba2FeOsO6, we synthesized powder samples of nonstoichiometric Ba2Fe1.12Os0.88 ...
The unique achondrite NWA 7325 is an unusual olivine gabbro composed chiefly of calcic plagioclase (An(85-93)), diopsidic pyroxene (En(50.1-54.0) Wo(44.8-49.3) Fs(0.6-1.3)), and forsteritic olivine (Fo(97)). It is Al and Mg-rich and Fe and Na-poor and disp ...