Paleomagnetic studies of rapakivi complexes in the Fennoscandian shield – Implications to the origin of Proterozoic massif-type anorthosite magmatism

Paleomagnetic studies have been performed on five rapakivi related complexes in Sweden and Finland. Poles of varying quality defined the majority ?1640–1497 Ma poles are clustering low latitudinal positions. By combining data from ?1500 intrusions a new high-quality pole (Plat: 13°N; Plon: 190°E; A95: 11°, K: 14) for Baltica has defined. Tectonic reconstructions, basis previously published data, indicate that experienced stable latitude to equatorial positions during 1640–1470 Ma, temporally coinciding with globally pronounced rapakivi-anorthosite magmatism. Our study argues against single hotspot source ?1640–1620 ?1590–1520 1470–1410 rapakivi-anorthosites, but supports model large-scale superswell under stationary low-latitude position supercontinent Nuna origin However, possibility convergent tectonism as cannot be ruled out.