Advanced

Zircon U–Pb-Hf isotope data in eclogite and metagabbro from southern Sweden reveal a common long-lived evolution and enriched source

Petersson, Andreas LU and Tual, Lorraine LU (2020) In GFF 142(4). p.253-266
Abstract

Several orogenies have shaped the bedrock of southern Sweden. While mafic intrusions represent significant sources of information for reconstructing geodynamics and crustal evolution, the characterization of the various generations of such intrusions in Sweden remains limited. We report in situ zircon U–Pb ages and Hf isotope data from a Fe-Ti eclogite and a coronitic metagabbro from the Eastern Segment in southern Sweden. Crystallisation ages at 1683 ± 17 Ma of the eclogite suggest affiliation with the surrounding 1730–1660 Ma Transscandinavian Igneous Belt intrusions that dominate the Eastern Segment. Secondary zircon growth and Pb-loss in the eclogite sample at 1459 ± 44 Ma and the crystallisation of the metagabbro at 1431 ± 26 Ma... (More)

Several orogenies have shaped the bedrock of southern Sweden. While mafic intrusions represent significant sources of information for reconstructing geodynamics and crustal evolution, the characterization of the various generations of such intrusions in Sweden remains limited. We report in situ zircon U–Pb ages and Hf isotope data from a Fe-Ti eclogite and a coronitic metagabbro from the Eastern Segment in southern Sweden. Crystallisation ages at 1683 ± 17 Ma of the eclogite suggest affiliation with the surrounding 1730–1660 Ma Transscandinavian Igneous Belt intrusions that dominate the Eastern Segment. Secondary zircon growth and Pb-loss in the eclogite sample at 1459 ± 44 Ma and the crystallisation of the metagabbro at 1431 ± 26 Ma overlap and are related to magmatic activity during the Hallandian orogeny. Zircon Hf isotope signatures with chondritic and sub-chondritic values at ~1683 Ma and ~1431 Ma, respectively, correspond to an enriched (or mildly depleted) source in line with a “Mixed Svecofennian Crustal Reservoir”. These isotope signatures are more enriched than those in the surrounding gneisses. Zircon isotope data from the herein analysed zircon grains indicate that the eclogite and metagabbro had an enriched mafic source in the mid to lower crust, or within the subcontinental lithospheric mantle below Fennoscandia.

(Less)
Please use this url to cite or link to this publication:
author
and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
eastern Segment, Eclogite, hallandian, lu–Hf, sveconorwegian, u–Pb, zircon
in
GFF
volume
142
issue
4
pages
14 pages
publisher
Taylor & Francis
external identifiers
  • scopus:85092328160
ISSN
1103-5897
DOI
10.1080/11035897.2020.1822438
language
English
LU publication?
yes
id
47b585ce-770d-47f9-99c6-bbb929d4a5ec
date added to LUP
2020-10-28 12:12:21
date last changed
2021-01-04 09:57:00
@article{47b585ce-770d-47f9-99c6-bbb929d4a5ec,
  abstract     = {<p>Several orogenies have shaped the bedrock of southern Sweden. While mafic intrusions represent significant sources of information for reconstructing geodynamics and crustal evolution, the characterization of the various generations of such intrusions in Sweden remains limited. We report in situ zircon U–Pb ages and Hf isotope data from a Fe-Ti eclogite and a coronitic metagabbro from the Eastern Segment in southern Sweden. Crystallisation ages at 1683 ± 17 Ma of the eclogite suggest affiliation with the surrounding 1730–1660 Ma Transscandinavian Igneous Belt intrusions that dominate the Eastern Segment. Secondary zircon growth and Pb-loss in the eclogite sample at 1459 ± 44 Ma and the crystallisation of the metagabbro at 1431 ± 26 Ma overlap and are related to magmatic activity during the Hallandian orogeny. Zircon Hf isotope signatures with chondritic and sub-chondritic values at ~1683 Ma and ~1431 Ma, respectively, correspond to an enriched (or mildly depleted) source in line with a “Mixed Svecofennian Crustal Reservoir”. These isotope signatures are more enriched than those in the surrounding gneisses. Zircon isotope data from the herein analysed zircon grains indicate that the eclogite and metagabbro had an enriched mafic source in the mid to lower crust, or within the subcontinental lithospheric mantle below Fennoscandia.</p>},
  author       = {Petersson, Andreas and Tual, Lorraine},
  issn         = {1103-5897},
  language     = {eng},
  number       = {4},
  pages        = {253--266},
  publisher    = {Taylor & Francis},
  series       = {GFF},
  title        = {Zircon U–Pb-Hf isotope data in eclogite and metagabbro from southern Sweden reveal a common long-lived evolution and enriched source},
  url          = {http://dx.doi.org/10.1080/11035897.2020.1822438},
  doi          = {10.1080/11035897.2020.1822438},
  volume       = {142},
  year         = {2020},
}