PROTERO-LITHO2
IPEV supported project, 2023-2025
The Geo-Ocean project PROTERO-LITHO2 supported by IPEV for 3 years aims to characterize the rheology of the Proterozoic continental lithosphere during the emplacement of the Gardar magmatic rift in SW Greenland ~1.2 billion years ago.
This rift is associated not only with large central mafic to alkaline magmatic intrusions -coveted for their uranium and rare earth contents- but also with very thick mafic planar intrusions, up to 500m (Cf. figure).
It is the mechanical conditions of injection of these dykes that are very intriguing. Current volcanic rift systems are associated with dykes only a few meters thick, both in the continental and oceanic domain. The giant Gardar dykes suggest that the mechanical properties of the lithosphere, and its thermicity, were very different in the Proterozoic than in the present.
Resources deployed
Methodology
- geophysical: receiver function method, gravimetry
- remote sensing: spectral analysis of compositional variations by in situ and satellite measurements
- geological: magma factories by ASM and EBSD
The objective is to characterize the dynamics of magma injection in these dykes as well as the structure of the crust and deeper lithosphere along 3 sections, 2 of which are orthogonal to the rift.
Team
The field and laboratory team will be composed of 8 international geologists, geophysicists and modelers, including 4 French.
The polar sailboat Vagabond will be used to install the instruments on land and as a field base.
The project will also include winter operations, with travel by boat and/or on the ice pack, for the maintenance of the seismic stations.
Contact :
Laurent Geoffroy, Université de Bretagne Occidentale, UMR 6538 Geo-Ocean