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  2. Late Neoproterozoic Amphibolite-Facies Metamorphism of a Pre-Caledonian Basement Block in Southwest Wedel Jarlsberg Land, Spitsbergen: New Evidence from U–Th–Pb Dating of Monazite
Author(s)
Abstract

Abstract Southwest Spitsbergen, Wedel Jarlsberg Land, consists of two Proterozoic crustal blocks with differing metamorphic histories. Both blocks experienced Caledonian greenschist-facies metamorphism, but only the southern block records an earlier pervasive M1 amphibolite-facies metamorphism and strong deformational fabric. In situ EMPA total-Pb monazite geochronology from both matrix and porphyroblast inclusion results indicate that the older M1 metamorphism occurred at 643 ± 9 Ma, consistent with published cooling ages of c. 620 Ma (hornblende) and 580 Ma (mica) obtained from these same rocks. This region thus contains a lithostratigraphic profile and metamorphic history which are unique within the Svalbard Archipelago. Documentation of a pervasive late Neoproterozoic Barrovian metamorphism is difficult to reconcile with a quiescent non-tectonic regime typically inferred for this region, based on the occurrence of rift-drift sequences on the Baltic and Laurentian passive margins. Instead, our new metamorphic age implies an exotic origin of the pre-Devonian basement exposed in SW Spitsbergen and supports models of terrane assembly postulated for the Svalbard Archipelago.
Format
Article
Identifier(s)
10.1017/S001675680800530X
Publication Date
2008-11-01
Publication Title
Cambridge University Press
Volume
145
Issue
6
First Page
822
Last Page
830
Keywords
Subject
Rights
http://rightsstatements.org/vocab/InC/1.0/
Community
Department of Earth Sciences
Permalink https://oaks.kent.edu/geolpubs/173
Majka, J., Mazur, S., Manecki, M., Czerny, J., & Holm, D. (2008). Late Neoproterozoic Amphibolite-Facies Metamorphism of a Pre-Caledonian Basement Block in Southwest Wedel Jarlsberg Land, Spitsbergen: New Evidence from U–Th–Pb Dating of Monazite (1–). Cambridge University Press. https://doi.org/10.1017/S001675680800530X
Majka, Jaroslaw, Stanislaw Mazur, Maciej Manecki, Jerzy Czerny, and Daniel Holm. 2008. “Late Neoproterozoic Amphibolite-Facies Metamorphism of a Pre-Caledonian Basement Block in Southwest Wedel Jarlsberg Land, Spitsbergen: New Evidence from U–Th–Pb Dating of Monazite”. Cambridge University Press. https://doi.org/10.1017/S001675680800530X.
Majka, Jaroslaw, et al. Late Neoproterozoic Amphibolite-Facies Metamorphism of a Pre-Caledonian Basement Block in Southwest Wedel Jarlsberg Land, Spitsbergen: New Evidence from U–Th–Pb Dating of Monazite. Cambridge University Press, 1 Nov. 2008, https://doi.org/10.1017/S001675680800530X.