Paleoproterozoic metamorphism in the northern Fennoscandian Shield: age constraints revealed by monazite ...
We have identified two contrasting styles of Paleoproterozoic metamorphism in the northern part of the Fennoscandian Shield. The Karelia and Lapland-Kola Provinces, comprising Archean and overlying Paleoproterozoic supracrustal rocks, show a typical medium pressure Barrovian-style metamorphism with...
| Main Authors: | , , , , , |
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| Format: | Dataset |
| Language: | unknown |
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Taylor & Francis
2020
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.6084/m9.figshare.11734173.v1 https://tandf.figshare.com/articles/dataset/Paleoproterozoic_metamorphism_in_the_northern_Fennoscandian_Shield_age_constraints_revealed_by_monazite/11734173/1 |
| Summary: | We have identified two contrasting styles of Paleoproterozoic metamorphism in the northern part of the Fennoscandian Shield. The Karelia and Lapland-Kola Provinces, comprising Archean and overlying Paleoproterozoic supracrustal rocks, show a typical medium pressure Barrovian-style metamorphism with commonly found kyanite-bearing mineral assemblages and ITD (isothermal decompression) PT paths. In the juxtaposed Svecofennia Province metamorphism represents low pressure-high temperature Buchan style with garnet-cordierite migmatites and intercalated andalusite-cordierite and andalusite-staurolite schists and sillimanite-muscovite gneisses. The retrograde PT paths show only a moderate uplift during cooling. U-Pb age determinations on monazite were made using the LA-ICP-MS from more than 80 samples from metasedimentary rocks. The sampling covered most parts of the Paleoproterozoic bedrock in Finland. The analyses reveal three peaks at c. 1.91 Ga, 1.86–1.88 Ga and at 1.79–1.81 Ga. The oldest, c. 1.91 Ga monazites ... |
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