1998/09/01 by Joseph G. Meert, Trond H. Torsvik, Elizabeth A. Eide +1 · 3 citations
Earth and Planetary Sciences · Biochemistry, Genetics and Molecular Biology · #Geological and Geochemical Analysis #Geomagnetism and Paleomagnetism Studies #Paleontology and Stratigraphy of Fossils #Baltica #Laurentia #Geology #Paleomagnetism #Rodinia #Paleontology #Dike #Apparent polar wander #Paleozoic #Geochronology #Rift #Tectonics #Ordovician
paper · doi:10.1086/516041
openalex publication_date 1998/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
The Fen Central Complex (FCC) and associated satellite dikes of the Fen Province in southern Norway record a magnetization dating to 583 Ma. The paleomagnetic pole calculated from these rocks falls at 56° N, 150° E (dp = 7°, dm = 10°) and compares favorably with two previous investigations. The mean inclination in our study is slightly steeper than that of one of the earlier studies and we attribute this to the fact that previous investigators inadvertently sampled younger (late Paleozoic/early Mesozoic) dikes in the area. The age of the Fen paleomagnetic pole is constrained by two consistent 40Ar/39Ar ages from these rocks, which average 583 ± 15 Ma, along with previously published ages ranging from 523–601 Ma. The Fen Central Complex, along with associated intrusions, were emplaced during minor extensional activity that occurred after continental separation between Baltica and Laurentia. This interpretation is consistent with our 580 Ma paleoreconstruction, which shows that Baltica had rifted and rotated from its 615 Ma position adjacent to Greenland. We interpret the ages and the tectonics to reflect opening of an ocean basin from north to south during the latest Neoproterozoic to earliest Paleozoic time (615–540 Ma). The polarity option for the Fen pole remains an important and open question due to recent suggestions of a true polar wander event in the mid‐Cambrian; however, we consider that the south polarity option offers the simplest tectonic model for the rifting of Rodinia and opening of the Iapetus Ocean between Baltica and Laurentia. Finally, we note the similarity of the Fen paleomagnetic pole to paleomagnetic poles of Permo‐Triassic age in Baltica and urge caution in the unequivocal use of the Fen pole as primary until further substantiated by coeval poles from Baltica.