Tomas Naeraa
Researcher
Seawater signatures in the supracrustal Lewisian Complex, Scotland
Author
Summary, in English
Marble in the supracrustal rocks of the Lewisian Complex, Tiree, includes chlorine-bearing amphiboles, chlorine-rich apatite, sulphur-rich scapolite, albite and phlogopite, all of which are regarded as evidence for evaporites in other metamorphosed sequences. Titanite yields U-Pb ages of ∼1.6 Ga, i.e. late Laxfordian, which excludes a younger imprint of sodium metasomatism. Traces of anhydrite, and isotopically heavy pyrite, also indicate deposition from seawater. Elsewhere in the Hebrides, tourmaline in Lewisian Complex marbles may represent seafloor exhalative deposits. Combined, the evidence suggests Lewisian Complex supracrustal marbles formed in an evaporative environment, like other Palaeoproterozoic successions across the North Atlantic region.
Department/s
- Lithosphere and Biosphere Science
Publishing year
2022-09-02
Language
English
Pages
1638-1646
Publication/Series
Geological Magazine
Volume
159
Issue
9
Document type
Journal article
Publisher
Cambridge University Press
Topic
- Geology
Keywords
- evaporites
- Lewisian
- marble
- Palaeoproterozoic
- scapolite
- Scotland
- Tiree
- titanite
Status
Published
ISBN/ISSN/Other
- ISSN: 0016-7568