Palaeomagnetism of Mesoproterozoic dykes from the Protogine Zone, southern Sweden and the enigmatic Sveconorwegian Loop

A palaeomagnetic study of samples from dykes in the Protogine Zone (PZ) south of Lake Vattern has yielded two characteristic magnetic components, A and B. A comparison with previous data and the Sveconorwegian Loop of the Fennoscandian Apparent Polar Wander Path (APWP) make it possible to estimate the age of the corresponding palaeomagnetic poles. They are situated close to the "Loop", which indicates ages between ca 1100 and 850 Ma. The Loop is based mainly on three clusters of palaeopoles, two situated at low latitude and one at intermediate to high latitude. The possible configuration of the Loop is discussed.