Paleoproterozoic (1.9–1.8 Ga) syn-orogenic magmatism, sedimentation and mineralization in the Bergslagen lithotectonic unit, Svecokarelian orogen
Document identifier: oai:DiVA.org:ltu-77174
Access full text here:
10.1144/M50-2017-40Keyword: Natural Sciences,
Earth and Related Environmental Sciences,
Geology,
Naturvetenskap,
Geovetenskap och miljövetenskap,
Geologi,
Bergslagen,
Fennoscandian shield,
Svecokarelian orogen,
Ore Geology,
MalmgeologiPublication year: 2020Abstract: Felsic volcanic rocks (c. 1.91–1.89 Ga) and interlayered limestone, hosting Zn–Pb–Ag ± Cu ± Au ± Fe sulphide and Fe oxide deposits, characterize the Bergslagen lithotectonic unit, Svecokarelian orogen, south-central Sweden. Three sulphide mines are currently in operation. Siliciclastic sedimentary rocks stratigraphically envelop this volcanic succession and all the rocks are intruded by a dominant calc-alkaline, c. 1.91–1.87 Ga plutonic suite. Fabric development associated with folding and localized shear deformation followed at c. 1.87–1.86 Ga (D1) and was succeeded by strongly partitioned strain (D2). Dextral transpression along steeply dipping, WNW–ESE or NW–SE shear zones prevailed in the northern and southern domains, whereas major folding with east to northeasterly axial surface traces and shearing along limbs occurred in the central domain. Open folding (D3) subsequently affected the western areas. Polyphase metamorphism under low-pressure and variable temperature conditions included anatexis at c. 1.86 Ga (M1) and 1.84–1.80 Ga (M2). More alkali–calcic magmatic activity, combined with the emplacement of anatectic granite and pegmatite, overlapped and succeeded the M1 and M2 migmatization events at c. 1.87–1.83 Ga and c. 1.82–1.75 Ga, respectively. The younger granites are genetically linked in part to W skarn deposits and host Mo sulphide mineralization. Switching between retreating and advancing subduction systems during three separate tectonic cycles along a convergent, active continental plate margin is inferred.
Authors
Michael Stephens
Luleå tekniska universitet; Geovetenskap och miljöteknik; Ore Geology
Other publications
>>
Nils Jansson
Luleå tekniska universitet; Geovetenskap och miljöteknik; Luleå University of Technology; Ore Geology
Other publications
>>
Record metadata
Click to view metadata
header:
identifier: oai:DiVA.org:ltu-77174
datestamp: 2021-04-19T12:52:21Z
setSpec: SwePub-ltu
metadata:
mods:
@attributes:
version: 3.7
recordInfo:
recordContentSource: ltu
recordCreationDate: 2019-12-14
identifier:
http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-77174
10.1144/M50-2017-40
2-s2.0-85084971014
titleInfo:
@attributes:
lang: eng
title: Paleoproterozoic (1.9–1.8 Ga) syn-orogenic magmatism sedimentation and mineralization in the Bergslagen lithotectonic unit Svecokarelian orogen
abstract: Felsic volcanic rocks (c. 1.91–1.89 Ga) and interlayered limestone hosting Zn–Pb–Ag ± Cu ± Au ± Fe sulphide and Fe oxide deposits characterize the Bergslagen lithotectonic unit Svecokarelian orogen south-central Sweden. Three sulphide mines are currently in operation. Siliciclastic sedimentary rocks stratigraphically envelop this volcanic succession and all the rocks are intruded by a dominant calc-alkaline c. 1.91–1.87 Ga plutonic suite. Fabric development associated with folding and localized shear deformation followed at c. 1.87–1.86 Ga (D1) and was succeeded by strongly partitioned strain (D2). Dextral transpression along steeply dipping WNW–ESE or NW–SE shear zones prevailed in the northern and southern domains whereas major folding with east to northeasterly axial surface traces and shearing along limbs occurred in the central domain. Open folding (D3) subsequently affected the western areas. Polyphase metamorphism under low-pressure and variable temperature conditions included anatexis at c. 1.86 Ga (M1) and 1.84–1.80 Ga (M2). More alkali–calcic magmatic activity combined with the emplacement of anatectic granite and pegmatite overlapped and succeeded the M1 and M2 migmatization events at c. 1.87–1.83 Ga and c. 1.82–1.75 Ga respectively. The younger granites are genetically linked in part to W skarn deposits and host Mo sulphide mineralization. Switching between retreating and advancing subduction systems during three separate tectonic cycles along a convergent active continental plate margin is inferred.
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
topic: Bergslagen
@attributes:
lang: eng
topic: Fennoscandian shield
@attributes:
lang: eng
topic: Svecokarelian orogen
@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
authority: ltu
namePart:
Stephens
Michael
role:
roleTerm: aut
affiliation:
Luleå tekniska universitet
Geovetenskap och miljöteknik
Ore Geology
nameIdentifier: micste
@attributes:
type: personal
authority: ltu
namePart:
Jansson
Nils
role:
roleTerm: aut
affiliation:
Luleå tekniska universitet
Geovetenskap och miljöteknik
Luleå University of Technology
Ore Geology
nameIdentifier:
niljan
0000-0002-2634-6953
originInfo:
dateIssued: 2020
publisher: Geological Society of London
place:
placeTerm: London
edition: 1
relatedItem:
@attributes:
type: host
titleInfo:
title: Sweden: Lithotectonic framework tectonic evolution and mineral resources
part:
extent:
start: 155
end: 206
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