New insights from field observations of the Younger giant dyke complex and mafic lamprophyres of the gardar province on Tuttutooq island, South Greenland

LK, RW, RC, LM and AM received funding from the Mining Institute of Scotland, Institute of Materials, Minerals and Mining, the Edinburgh Geological Society, the Augustine Courtauld Trust and the Scott Polar Research Institute. LK received funding from the Society of Economic Geology Hickok-Radford F...

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Bibliographic Details
Published in:GEUS Bulletin
Main Authors: Koopmans, Lot, Webster, Robert A., Changleng, Rory, Mathieson, Lucy, Murphy, Alasdair J., Finch, Adrian A., McCarthy, William
Other Authors: University of St Andrews. School of Earth & Environmental Sciences, University of St Andrews. Scottish Oceans Institute, University of St Andrews. St Andrews Isotope Geochemistry
Format: Article in Journal/Newspaper
Language:English
Published: 2021
Subjects:
GE
QE
Online Access:http://hdl.handle.net/10023/23544
https://doi.org/10.34194/geusb.v47.6526
https://geusbulletin.org/index.php/geusb/article/view/6526/14176
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Summary:LK, RW, RC, LM and AM received funding from the Mining Institute of Scotland, Institute of Materials, Minerals and Mining, the Edinburgh Geological Society, the Augustine Courtauld Trust and the Scott Polar Research Institute. LK received funding from the Society of Economic Geology Hickok-Radford Fund. The Gardar Province of south Greenland is defined by the products of alkaline igneous magmatism during the Mesoproterozoic. The most laterally extensive Gardar intrusions are a series of giant dyke complexes best exposed on the Tuttutooq archipelago. We present new field observations and a geological map of north-east Tuttutooq island that provide fresh insights into the temporal evolution of the Younger giant dyke complex and two associated ultramafic lamprophyres. Our data demonstrate that distinctive crystallisation regimes occurred in different sectors of the dyke complex, leading to the formation of marginal gabbros and ovoid pod-like domains displaying lamination, modal layering and/or more evolved differentiates. We infer that at least two pulses of magma contributed to the formation of the Younger giant dyke complex. In addition, the relative ages of two ultramafic lamprophyre diatremes are constrained and attributed to two distinct phases of rifting in the Gardar Province. Publisher PDF Peer reviewed