Cargando…

Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating

In situ LA-MC-ICP-MS U-Pb zircon geochronology combined with cathodoluminescence imaging were carried out to determine protolith and metamorphic ages of orthogneisses from the Western Tatra Mountains (Central Western Carpathians). The metamorphic complex is subdivided into two units (the Lower Unit...

Descripción completa

Detalles Bibliográficos
Autores principales: Burda, Jolanta, Klötzli, Urs
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer Vienna 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4811099/
https://www.ncbi.nlm.nih.gov/pubmed/27069306
http://dx.doi.org/10.1007/s00710-011-0176-4
_version_ 1782423902203412480
author Burda, Jolanta
Klötzli, Urs
author_facet Burda, Jolanta
Klötzli, Urs
author_sort Burda, Jolanta
collection PubMed
description In situ LA-MC-ICP-MS U-Pb zircon geochronology combined with cathodoluminescence imaging were carried out to determine protolith and metamorphic ages of orthogneisses from the Western Tatra Mountains (Central Western Carpathians). The metamorphic complex is subdivided into two units (the Lower Unit and the Upper Unit). Orthogneisses of the Lower Unit are mostly banded, fine- to medium-grained rocks while in the Upper Unit varieties with augen structures predominate. Orthogneisses show a dynamically recrystallised mineral assemblage of Qz + Pl + Bt ± Grt with accessory zircon and apatite. They are peraluminous (ASI = 1.20–1.27) and interpreted to belong to a high-K calc-alkaline suite of a VAG–type tectonic setting. LA-MC-ICP-MS U-Pb zircon data from samples from both units, from crystals with oscillatory zoning and Th/U > 0.1, yield similar concordia ages of ca. 534 Ma. This is interpreted to reflect the magmatic crystallization age of igneous precursors. These oldest meta-magmatics so far dated in the Western Tatra Mountains could be linked to the fragmentation of the northern margin of Gondwana. In zircons from a gneiss from the Upper Unit, cores with well-developed oscillatory zoning are surrounded by weakly luminescent, low contrast rims (Th/U < 0.1). These yield a concordia age of ca. 387 Ma corresponding to a subsequent, Eo-Variscan, high-grade metamorphic event, connected with the formation of crustal-scale nappe structures and collision-related magmatism.
format Online
Article
Text
id pubmed-4811099
institution National Center for Biotechnology Information
language English
publishDate 2011
publisher Springer Vienna
record_format MEDLINE/PubMed
spelling pubmed-48110992016-04-09 Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating Burda, Jolanta Klötzli, Urs Mineral Petrol Special Issue Accessory Minerals In situ LA-MC-ICP-MS U-Pb zircon geochronology combined with cathodoluminescence imaging were carried out to determine protolith and metamorphic ages of orthogneisses from the Western Tatra Mountains (Central Western Carpathians). The metamorphic complex is subdivided into two units (the Lower Unit and the Upper Unit). Orthogneisses of the Lower Unit are mostly banded, fine- to medium-grained rocks while in the Upper Unit varieties with augen structures predominate. Orthogneisses show a dynamically recrystallised mineral assemblage of Qz + Pl + Bt ± Grt with accessory zircon and apatite. They are peraluminous (ASI = 1.20–1.27) and interpreted to belong to a high-K calc-alkaline suite of a VAG–type tectonic setting. LA-MC-ICP-MS U-Pb zircon data from samples from both units, from crystals with oscillatory zoning and Th/U > 0.1, yield similar concordia ages of ca. 534 Ma. This is interpreted to reflect the magmatic crystallization age of igneous precursors. These oldest meta-magmatics so far dated in the Western Tatra Mountains could be linked to the fragmentation of the northern margin of Gondwana. In zircons from a gneiss from the Upper Unit, cores with well-developed oscillatory zoning are surrounded by weakly luminescent, low contrast rims (Th/U < 0.1). These yield a concordia age of ca. 387 Ma corresponding to a subsequent, Eo-Variscan, high-grade metamorphic event, connected with the formation of crustal-scale nappe structures and collision-related magmatism. Springer Vienna 2011-09-27 2011 /pmc/articles/PMC4811099/ /pubmed/27069306 http://dx.doi.org/10.1007/s00710-011-0176-4 Text en © The Author(s) 2011 https://creativecommons.org/licenses/by-nc/4.0/ This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
spellingShingle Special Issue Accessory Minerals
Burda, Jolanta
Klötzli, Urs
Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating
title Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating
title_full Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating
title_fullStr Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating
title_full_unstemmed Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating
title_short Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating
title_sort pre-variscan evolution of the western tatra mountains: new insights from u-pb zircon dating
topic Special Issue Accessory Minerals
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4811099/
https://www.ncbi.nlm.nih.gov/pubmed/27069306
http://dx.doi.org/10.1007/s00710-011-0176-4
work_keys_str_mv AT burdajolanta prevariscanevolutionofthewesterntatramountainsnewinsightsfromupbzircondating
AT klotzliurs prevariscanevolutionofthewesterntatramountainsnewinsightsfromupbzircondating