Zircon U–Pb and Hf – isotopes from the eastern part of the Sveconorwegian Orogen, SW Sweden: implications for the growth of
Fennoscandia
Andreas Petersson
Anders Scherstén
Jenny Andersson
Charlotte Möller
10.6084/m9.figshare.3453425.v1
https://geolsoc.figshare.com/articles/dataset/Zircon_U_Pb_and_Hf_isotopes_from_the_eastern_part_of_the_Sveconorwegian_Orogen_SW_Sweden_implications_for_the_growth_of___Fennoscandia/3453425
<p>Current models for the growth of Fennoscandia, including the eastern part of the Sveconorwegian Province, are largely based
on U–Pb data and do not discriminate between juvenile and reworked crust. Here we present new combined U–Pb and Hf isotopic
data, from the Eastern Segment and the Idefjorden terrane of the Sveconorwegian Province, and suggest a revised model of crustal
growth. Most of the crystalline basement in this part of the shield formed by mixing of a 2.1–1.9 Ga juvenile component and
Archaean crust. Archaean reworking decreases between 1.9 and 1.7 Ga and a mixed Svecofennian crustal reservoir is generated.
Succeeding magmatism between 1.7 and 1.4 Ga indicates reworking of this reservoir with little or no crust generation. At <em>c.</em> 1.2 Ga, an influx of juvenile magma is recorded by granite to quartz-syenite magmatism with mildly depleted (ε<sub>Hf 1.18 Ga</sub> of <em>c.</em> 3) signatures. The amount of recycled crust in the 1.9–1.7 Ga arc system is in contrast to previously proposed models for
the growth of the southwestern part of the Fennoscandian Shield. This model agrees with long-term subduction along the western
margin of Fennoscandia, but suggests substantial reworking of existing crust and decreasing amounts of <1.9 Ga crustal growth.
</p>
2016-06-21 11:23:54
Svecofennian crustal reservoir
Fennoscandia
Sveconorwegian Province
Hf
Archaean reworking decreases
model
SW
Ga
Geology