Archean (>2.6 Ga) and Paleoproterozoic (2.5–1.8 Ga), pre- and syn-orogenic magmatism, sedimentation and mineralization in the Norrbotten and Överkalix lithotectonic units, Svecokarelian orogen
Lithotectonic Framework, Tectonic Evolution and Mineral Resources
Document identifier: oai:DiVA.org:ltu-77984
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10.1144/M50-2016-29Keyword: Natural Sciences,
Earth and Related Environmental Sciences,
Geology,
Naturvetenskap,
Geovetenskap och miljövetenskap,
Geologi,
Ore Geology,
MalmgeologiPublication year: 2020Abstract: Two lithotectonic units (the Norrbotten and Överkalix units) occur inside the Paleoproterozoic (2.0–1.8 Ga) Svecokarelian orogen in northernmost Sweden. Archean (2.8–2.6 Ga and possibly older) basement, affected by a relict Neoarchean tectonometamorphic event, and early Paleoproterozoic (2.5–2.0 Ga) cover rocks constitute the pre-orogenic components in the orogen that are unique in Sweden. Siliciclastic sedimentary rocks, predominantly felsic volcanic rocks, and both spatially and temporally linked intrusive rock suites, deposited and emplaced at 1.9–1.8 Ga, form the syn-orogenic component. These magmatic suites evolved from magnesian and calc-alkaline to alkali–calcic compositions to ferroan and alkali–calcic varieties in a subduction-related tectonic setting. Apatite–Fe oxide, including the world's two largest underground Fe ore mines (Kiruna and Malmberget), skarn-related Fe oxide, base metal sulphide, and epigenetic Cu–Au and Au deposits occur in the Norrbotten lithotectonic unit. Low- to medium-pressure and variable temperature metamorphic conditions and polyphase Svecokarelian ductile deformation prevailed. The general northwesterly or north-northeasterly structural grain is controlled by ductile shear zones. The Paleotectonic evolution after the Neoarchean involved three stages: (1) intracratonic rifting prior to 2.0 Ga; (2) tectonic juxtaposition of the lithotectonic units during crustal shortening prior to 1.89 Ga; and (3) accretionary tectonic evolution along an active continental margin at 1.9–1.8 Ga.
Authors
Stefan Bergman
Geological Survey of Sweden
Other publications
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Pär Weihed
Luleå tekniska universitet; Geovetenskap och miljöteknik
Other publications
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header:
identifier: oai:DiVA.org:ltu-77984
datestamp: 2021-04-19T12:49:08Z
setSpec: SwePub-ltu
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recordCreationDate: 2020-03-06
identifier:
http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-77984
10.1144/M50-2016-29
2-s2.0-85087114724
titleInfo:
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lang: eng
title: Archean (>2.6 Ga) and Paleoproterozoic (2.5–1.8 Ga) pre- and syn-orogenic magmatism sedimentation and mineralization in the Norrbotten and Överkalix lithotectonic units Svecokarelian orogen
abstract: Two lithotectonic units (the Norrbotten and Överkalix units) occur inside the Paleoproterozoic (2.0–1.8 Ga) Svecokarelian orogen in northernmost Sweden. Archean (2.8–2.6 Ga and possibly older) basement affected by a relict Neoarchean tectonometamorphic event and early Paleoproterozoic (2.5–2.0 Ga) cover rocks constitute the pre-orogenic components in the orogen that are unique in Sweden. Siliciclastic sedimentary rocks predominantly felsic volcanic rocks and both spatially and temporally linked intrusive rock suites deposited and emplaced at 1.9–1.8 Ga form the syn-orogenic component. These magmatic suites evolved from magnesian and calc-alkaline to alkali–calcic compositions to ferroan and alkali–calcic varieties in a subduction-related tectonic setting. Apatite–Fe oxide including the world's two largest underground Fe ore mines (Kiruna and Malmberget) skarn-related Fe oxide base metal sulphide and epigenetic Cu–Au and Au deposits occur in the Norrbotten lithotectonic unit. Low- to medium-pressure and variable temperature metamorphic conditions and polyphase Svecokarelian ductile deformation prevailed. The general northwesterly or north-northeasterly structural grain is controlled by ductile shear zones. The Paleotectonic evolution after the Neoarchean involved three stages: (1) intracratonic rifting prior to 2.0 Ga; (2) tectonic juxtaposition of the lithotectonic units during crustal shortening prior to 1.89 Ga; and (3) accretionary tectonic evolution along an active continental margin at 1.9–1.8 Ga.
subject:
@attributes:
lang: eng
authority: uka.se
topic:
Natural Sciences
Earth and Related Environmental Sciences
Geology
@attributes:
lang: swe
authority: uka.se
topic:
Naturvetenskap
Geovetenskap och miljövetenskap
Geologi
@attributes:
lang: eng
authority: ltu
topic: Ore Geology
genre: Research subject
@attributes:
lang: swe
authority: ltu
topic: Malmgeologi
genre: Research subject
language:
languageTerm: eng
genre:
publication/book-chapter
ref
note:
Published
2
name:
@attributes:
type: personal
namePart:
Bergman
Stefan
role:
roleTerm: aut
affiliation: Geological Survey of Sweden
@attributes:
type: personal
authority: ltu
namePart:
Weihed
Pär
role:
roleTerm: aut
affiliation:
Luleå tekniska universitet
Geovetenskap och miljöteknik
nameIdentifier:
pawe
0000-0003-3879-3897
originInfo:
dateIssued: 2020
publisher: Geological Society of London
relatedItem:
@attributes:
type: host
titleInfo:
title: Sweden
subTitle: Lithotectonic Framework Tectonic Evolution and Mineral Resources
part:
extent:
start: 27
end: 81
identifier: 978-1-78620-460-8
@attributes:
type: series
titleInfo:
title: Memoirs of the Geological Society of London
partNumber: 50
identifier: 0435-4052
physicalDescription:
form: print
typeOfResource: text