Continental crust beneath southeast Iceland

Trond H. Torsvik*, Hans E F Amundsen, Reidar G. Trønnes, Pavel V. Doubrovine, Carmen Gaina, Nick J. Kusznir, Bernhard Steinberger, Fernando Corfu, Lewis D. Ashwal, William L. Griffin, Stephanie C. Werner, Bjørn Jamtveit

*Corresponding author for this work

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

The magmatic activity (0-16 Ma) in Iceland is linked to a deep mantle plume that has been active for the past 62 My. Icelandic and northeast Atlantic basalts contain variable proportions of two enriched components, interpreted as recycled oceanic crust supplied by the plume, and subcontinental lithospheric mantle derived from the nearby continental margins. A restricted area in southeast Iceland - and especially the Öræfajökull volcano - is characterized by a unique enriched-mantle component (EM2-like) with elevated 87Sr/86Sr and 207Pb/204Pb. Here, we demonstrate through modeling of Sr-Nd- Pb abundances and isotope ratios that the primitive Öræfajökull melts could have assimilated 2-6% of underlying continental crust before differentiating to more evolved melts. From inversion of gravity anomaly data (crustal thickness), analysis of regional magnetic data, and plate reconstructions, we propose that continental crust beneath southeast Iceland is part of ∼350-km-long and 70-km-wide extension of the Jan Mayen Microcontinent (JMM). The extended JMM was marginal to East Greenland but detached in the Early Eocene (between 52 and 47 Mya); by the Oligocene (27 Mya), all parts of the JMM permanently became part of the Eurasian plate following a westward ridge jump in the direction of the Iceland plume.

Original languageEnglish
Pages (from-to)E1818-E1827
Number of pages10
JournalProceedings of the National Academy of Sciences of the United States of America
Volume112
Issue number15
DOIs
Publication statusPublished - 14 Apr 2015

Fingerprint Dive into the research topics of 'Continental crust beneath southeast Iceland'. Together they form a unique fingerprint.

Cite this