Evidence of a Late Precambrian (637 Ma) deformational event in the Caledonides of northern Sweden

The Caledonian nappes in Scandinavia record two main phases of early Paleozoic metamorphism, but their pre-Caledonian tectonothermal history and paleogeographic position are largely unknown. Here we present a U-Pb age of 637+/-3 Ma for metamorphic titanite in the 1776+/-4 Ma (zircon age) Skarja gran...

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Bibliographic Details
Main Authors: Rehnström, Emma, Corfu, F, Torsvik, Trond H
Format: Article in Journal/Newspaper
Language:English
Published: University of Chicago Press 2002
Subjects:
Geology
Skarja
Northern Sweden
Online Access:https://lup.lub.lu.se/record/331654
Description
Summary:The Caledonian nappes in Scandinavia record two main phases of early Paleozoic metamorphism, but their pre-Caledonian tectonothermal history and paleogeographic position are largely unknown. Here we present a U-Pb age of 637+/-3 Ma for metamorphic titanite in the 1776+/-4 Ma (zircon age) Skarja granitic gneiss in northern Sweden. The titanite age is interpreted to represent a Neoproterozoic tectonometamorphic overprint. Geochronologic and paleogeographic considerations suggest that the gneiss was located at the outermost margin of pre-Caledonian (northwest) Baltica and was affected by Neoproterozoic tectonic activity related to terrane accretion, the Baikalian (or Timanian) orogeny, coincident with Cadomian terrane accretion along the Gondwanan margin of northern South America and northwest Africa.

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