TECTONOSTRATIGRAPHY OF THE CALEDONIAN BASEMENT OF MOSSELHALVØYA (NY FRIESLAND). RiS ID: 10101

This project is dedicated for fieldwork in the Caledonides of northern Svalbard. Main emphasis will be given to the metasedimentary rocks of the Planetfjella Group and ultramafic rocks occurring within the Atomfjella Complex in Ny Frieslan. The Planetfjella Group forms the uppermost tectonostratigraphic unit of the Lower Hecla Hoek of northern Ny Friesland and belongs to the Mosselhalvøya Nappe (Witt-Nilsson et al. 1998). Notably, the base of the Mosselhalvøya Thrust is underlined by numerous lenses of ultramafic rocks, which suggests that the contact between the Planetfjella Group and the underlying Polhem Group is a major discontinuity. Here we plan: 1) to profile in detail the Planetfejlla Group and sample several geographically and geologically (different metamorphic grades) varying set of samples for provenance and metamorphism dating; 2) to sample and study in detail somewhat enigmatic ultramafic rocks occurring beneath the Mosselhalvøya Thrust. The samples collected in frame of this project will be used for petrological and geochronological studies. The microprobe chemical analysis of minerals, whole rock chemistry as well as chemical and istopic dating of zircon and monazite are planned. Mineral chemistry data will be used for pressure-temperature estimates of the Planetfjella Group, based on the classical geothermobarometry and thermodynamic phase equilibrium modeling.