Publication detail

The 2023 Litli-Hrútur eruption of the Fagradalsfjall Fires, SW-Iceland: Insights from trace element compositions of olivine

KRMÍČEK, L. TROLL, V. R. THORDARSON, T. BRABEC, M. MORELAND, W. M. MAŤO, A.

Original Title

The 2023 Litli-Hrútur eruption of the Fagradalsfjall Fires, SW-Iceland: Insights from trace element compositions of olivine

Type

journal article in Web of Science

Language

English

Original Abstract

This study provides data on the trace element composition of olivine from olivine tholeiitic basalts sampled during the July-August 2023 Litli-Hrutur eruption of the Fagradalsfjall Fires in the Reykjanes Volcanic Belt. Chemistry of the Litli-Hrutur olivine is characteristic for volcanic olivine crystals that represent products of magmatic crystallisation. The investigated olivine megacrysts show forsterite (Fo) content in the range of 81 (rims) to 85 (cores) mole percent [defined as Fo = Mg/(Mg + Fe)]. Olivine Ni concentrations (1540-1840 ppm) correlate positively with the Fo contents. In addition, Ca contents show a range from 1890 to 2460 ppm at relatively low Ti concentrations. Olivine from the Litli-Hrutur samples shows an equilibrium with peridotitic mantle melts, yet the data show that the 2023 Litli-Hrutur and the 2022 Meradalir olivine populations crystallised from compositionally more evolved magma batches than olivine crystals from the 2021 Geldingadalir eruption of the Fagradalsfjall Fires. These results imply that magmatic differentiation has taken place between the initial 2021 events and the subsequent 2022 and 2023 eruptions as a result of crystal-liquid fractionation, shifting the overall magma chemistry towards more evolved compositions with time. This implies that fractional crystallisation in sub -alkaline magma reservoirs operates on the scale of years, which is a fundamental advance in our understanding of these common magmatic systems.

Keywords

olivine; Reykjanes Peninsula; Litli-Hrútur lava; peridotitic mantle; LA-ICP-MS

Authors

KRMÍČEK, L.; TROLL, V. R.; THORDARSON, T.; BRABEC, M.; MORELAND, W. M.; MAŤO, A.

Released

17. 3. 2024

Publisher

MASARYK UNIV PRESS

Location

Brno

ISBN

1805-0689

Periodical

Czech Polar Reports

Year of study

13

Number

2

State

Czech Republic

Pages from

257

Pages to

270

Pages count

14

URL

https://journals.muni.cz/CPR/article/view/38145/32443

BibTex

@article{BUT188335,
  author="Lukáš {Krmíček} and Valentin R. {Troll} and Thor {Thordarson} and Marek {Brabec} and William M. {Moreland} and Adam {Maťo}",
  title="The 2023 Litli-Hrútur eruption of the Fagradalsfjall Fires, SW-Iceland: Insights from trace element compositions of olivine",
  journal="Czech Polar Reports",
  year="2024",
  volume="13",
  number="2",
  pages="257--270",
  doi="10.5817/CPR2023-2-20",
  issn="1805-0689",
  url="https://journals.muni.cz/CPR/article/view/38145/32443"
}