Detrital zircon U-Pb geochronology of a metasomatic calc-silicate in the Tsäkkok Lens, Scandinavian Caledonides

The Tsäkkok Lens of the Seve Nappe Complex in Scandinavian Caledonides comprises eclogite bodies hosted within metasedimentary rocks. These rocks are thought to be derived from outermost margin Baltica along periphery Iapetus Ocean, but detrital records sedimentary lacking.Many outcrops lens expose both well-foliated metapelitic and massive calc-silicates. contacts between these two lithologies irregular observed trend at all angles high-pressure foliation metapelites. Where folding is present metapelites, calc-silicate also locally folded. relationships suggest metasomatism metapelites during Caledonian orogenesis. Zircon U-Pb geochronology was conducted on sixty-one zircon grains a sample investigate if they recorded metasomatic event assess populations. predominantly show oscillatory zoning, sometimes with thin, homogeneous rims that have embayed oscillatory-zoned cores. cores yielded prominent early Stenian, Calymmian, Statherian populations subordinate number Tonian grains. exhibit dissolution-reprecipitation or new growth provide ages span similar time frames, indicating overprinting successive tectonic events. Altogether, record suggests may correlated Neoproterozoic basins preserved allochthonous positions northern extents Orogen.