Trace Element Concentrations in Amphibole and/or Clinopyroxene from Composite Mantle Xenoliths of the West Eifel (Germany): An Ion-Microprobe Study

G. Witt-Eickschen
1994 Mineralogical magazine  
Geochemical studies of peridotite wall rocks adjacent to veins observed in composite mantle xenoliths and peridotite massifs, show that both the enrichment of incompatible elements in anhydrous peridotites (cryptic metasomatism) and the formation of amphibole (modal metasomatism) in the mantle lithosphere may sometimes be linked to a single event of peridotite-magma interaction, which can be modelled by chromatographic fractionation (e.g. Vasseur et aL, 1991; Nielson et al., 1993). In order to
more » ... 1993). In order to get more knowledge of the nature of the metasomatism beneath the West Eifel (Germany) ion-microprobe analyses of amphibole and/or clinopyroxene were performed for 25 composite xenoliths showing 0.5-3 cm broad veins crosscutting spinel lherzolite or harzburgite hosts. Two types of xenolith are distinguished: Type (I) is composed of amphibole-free, cryptically metasomatized, high temperature IN IL,m I ISm[ I-~-r ~a' t L-~-I
doi:10.1180/minmag.1994.58a.2.245 fatcat:vm34bb5vbzhcdloy2bm62tsqeu