The Mesoproterozoic (1.47-1.44 Ga) orogenic magmatism in Fennoscandia; Baddeleyite U-Pb dating of a suite of massif-type anorthosites in S Sweden

Summary, in English

The Jonkoping Anorthositic Suite (JAS) in S. Sweden has characteristics typical for (Proterozoic) massif-type anorthosites. The interstitial liquid of these plagioclase-porphyritic rocks solidified at 1,455 +/- A 6 Ma, as determined by U-Pb isotope analysis of baddeleyite. The JAS developed during a regional 1.47-1.44 event in Fennoscandia that generated widespread mafic magmatism (basalts, and diabase dykes and sills) in the north and emplacement of felsic plutons in the south. The event of 1.47-1.44 Ga magmatism in Fennoscandia largely coincides in age with dynamic high-grade metamorphism in SW Sweden and was probably related to convergent active-margin processes during the Danopolonian orogeny.