The origin of multiphase solid inclusions in orogenic garnet peridotite: a case study of Plesovice peridotite in the Bohemian Massif

Abstract

Plešovice peridotite occurs as a lenticular body in the high-P type Gföhl granulite derived from crustal materials in the Bohemian Massif, Czech Republic. Plešovice peridotite was originally harzburgite and then suffered metasomatic enrichments resulting in the presence of phlogopite, apatite, monazite, U-Th oxide, ThSiO4, dolomite, and zircon. These metasomatic minerals occur not only as isolated phases in the matrix, but also as multiphase solid (MS) inclusions with negative crystal shapes in the chromian spinel. Ferrando et al. (2005) have proposed that such MS inclusions may be the frozen remnant of supercritical fluids or silicate melts. Thus it is plausible that MS inclusions in our study are fossils of metasomatic agents that have invaded into the Plešovice peridotites at the root zone of Variscan Orogen. We would like to introduce the nature of MS inclusions and the timing of the incorporation of metasomatic agents in the presentation.