English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Geochronological constraints for a two-stage history of the Sveconorwegian rare-element pegmatite province formation

Rosing-Schow, N., Romer, R. L., Müller, A., Corfu, F., Škoda, R., Friis, H. (2023): Geochronological constraints for a two-stage history of the Sveconorwegian rare-element pegmatite province formation. - Precambrian Research, 384, 106944.
https://doi.org/10.1016/j.precamres.2022.106944

Item is

Files

show Files
hide Files
:
5015810.pdf (Publisher version), 18MB
Name:
5015810.pdf
Description:
-
Visibility:
Public
MIME-Type / Checksum:
application/pdf / [MD5]
Technical Metadata:
Copyright Date:
-
Copyright Info:
-

Locators

show

Creators

show
hide
 Creators:
Rosing-Schow, N.1, Author
Romer, R. L.2, Author              
Müller, A.1, Author
Corfu, F.1, Author
Škoda, R.1, Author
Friis, H.1, Author
Affiliations:
1External Organizations, ou_persistent22              
23.1 Inorganic and Isotope Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum, ou_146040              

Content

show
hide
Free keywords: Pegmatite, U-Pb dating, Columbite group minerals, Monazite, Sveconorwegian orogen, Grenville orogen
 Abstract: Most pegmatites of southern Norway seem to be derived from anatectic melting of metamorphic rocks during the Sveconorwegian orogeny rather than to be highly evolved residual melts derived from granites. We test this hypothesis by providing new age data for thirteen pegmatites and one granite. Based on these new age data, we distinguish two age groups of Sveconorwegian pegmatites (>1,000 m3 in size); Group 1: 1100–1030 Ma and Group 2: 930–890 Ma. All pegmatites except those from the Østfold area crystallized significantly earlier or later than adjacent granites. The Tørdal granite, yielding an age of 946 ± 4 Ma, is about 40 Ma older than the adjacent pegmatites. Field evidence and the age difference between pegmatites and granites supports an anatectic origin for these pegmatites. Sources of these pegmatite melts are biotite- and biotite-amphibole gneisses and amphibolites. Group 1 pegmatites formed in transpressional regimes after peak metamorphism, whereas Group 2 pegmatites formed in an extensional regime and the required heat for partial melting was provided by mafic magma underplating. Differences in the rheological behavior of amphibolite and granitic gneiss during extensional tectonics are the major reason why Group 2 pegmatites occur preferentially in large amphibolite bodies. Under mid-crustal conditions, amphibolite reacts brittle to semi-brittle forming open structures in an extensional tectonic regime where partial melts drained into. Granitic gneisses react in a ductile manner and do not have the ability to drain partial melt. Pegmatite formation in the Grenville Province, i.e., the Laurentian part of the Grenville–Sveconorwegian orogenic belt, formed between ca. 1090 and 980 Ma peaking at 1010 to 980 Ma. Thus, the Grenville peak postdates the Sveconorwegian Group 1 peak by about 30 Ma. These pegmatites formed in similar orogenic settings, implying that similar tectono-metamorphic developments along the Grenville–Sveconorwegian orogenic belt were diachronous. We conclude that local anatexis is the major pegmatite-melt forming process in the Sveconorwegian as well as Grenville orogen. Local anatexis also may be important in other pegmatite provinces.

Details

show
hide
Language(s):
 Dates: 20222023
 Publication Status: Finally published
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: DOI: 10.1016/j.precamres.2022.106944
GFZPOF: p4 T8 Georesources
OATYPE: Hybrid Open Access
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Precambrian Research
Source Genre: Journal, SCI, Scopus
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 384 Sequence Number: 106944 Start / End Page: - Identifier: CoNE: https://gfzpublic.gfz-potsdam.de/cone/journals/resource/journals409
Publisher: Elsevier