Tracing the SW border of the Svecofennian Domain in the Baltic Sea region: evidence from petrology and geochronology from a granodioritic migmatite

Abstract Geological investigations of a part the crystalline basement in Baltic Sea have been performed on drill core collected from depth 1092–1093 m beneath Phanerozoic sedimentary cover offshore Latvian/Lithuanian border. The sample was analyzed for geochemistry and dated with SIMS U–Pb zircon method. Inherited cores this migmatized granodioritic orthogneiss an age 1854 ± 15 Ma. Its chemical composition are correlated oldest generation granitoids Transscandinavian Igneous Belt (TIB), which occur along southwestern margin Svecofennian Domain Fennoscandian Shield southern Gotland northwestern Lithuania. It is suggested that border located at short distance to SW investigated site. majority population shows migmatization occurred 1812 5 Ma, possible evidence disturbance during Sveconorwegian orogeny.