PALAEOMAGNETISM OF 935 MA MAFIC DYKES IN SOUTHERN SWEDEN AND IMPLICATIONS FOR THE SVECONORWEGIAN LOOP

Abstract

New palaeomagnetic results for the 935 Ma Göteborg-Slussen mafic dykes in southern Sweden provide a well-dated high-quality palaeomagnetic pole for Early Neoproterozoic Baltica. New U-Pb geochronological data for several palaeomagnetically studied mafic intrusions yield three additional well-dated palaeopoles and one virtual geomagnetic pole. This set of dated poles suggests minimal drift of Baltica in moderate latitudes between ~965 and 915 Ma. They also support the hypothesis of a post-900 Ma regional remagnetization event in SW Sweden and SW Norway. The positions of three distinct clusters of ~1100 to 850 Ma palaeopoles suggest a clockwise time progression of the Baltica apparent polar wander path (the Sveconorwegian Loop) during this time interval. New well-dated palaeomagnetic poles for ~970 to 900 Ma from Laurentia are required to verify the palaeogeographic reconstructions of Baltica and Laurentia. © 2006 The Authors Journal compilation © 2006 RAS.