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2024 International Symposium on Deep Earth Exploration and Practices, November 2024
Abstract:
Plume-lithosphere interactions are key in the coupling of
deep Earth and surface processes, impacting deformation
and evolution of sedimentary basins and continental
topography at different spatial scales (Cloetingh et al., 2022,
2023). The North Atlantic region is a prime example of the
interaction between plate tectonic movements and thermal
instabilities in the Earth’s mantle. The opening of the
Labrador Sea/Baffin Bay and the North Atlantic, the
widespread volcanism and the localized uplift of the
topography in Greenland and the North Atlantic are
traditionally attributed to the thermal effect of the Iceland
mantle plume. However, several prominent features of the
region―the temporal synchrony of magmatism and break-
up events, the symmetrical configuration of the Greenland–
Iceland–Faroe Ridge, and the diachronous domal uplift of
the North Atlantic rifted margins―have inspired
alternative, “non-plume” views. According to these, the
North Atlantic Igneous Province (NAIP) and Iceland
magmatism originate from plate tectonic processes sourced
in the shallow upper mantle, at odds with the unequivocal
presence of deep-seated low-velocity seismic anomalies
beneath Iceland and the isotopic signatures of plume-
derived melts in Cenozoic magmatic units.
We resolve apparent contradictions in the observations
and reconstructions and reconcile end-member concepts of
the Late Mesozoic-Cenozoic evolution of the North
Atlantic realm. We show that simultaneous Paleocene
(~62–58 Ma) magmatism in Western Greenland/Baffin
Island and the British Isles, which together form the
NAIP, is driven by two processes accidently coinciding in
time: 1) the propagation of the Labrador Sea/Baffin Bay
spreading axis has overlapped with the ~100–80 Ma dated
segment of the Iceland hotspot track near the West
Greenland margin, while 2) the actual tail of the Iceland
plume has reached the eastern continental margin of
Greenland, allowing a horizontal flow of hot plume
material along corridors of relatively thinned lithosphere
towards Southern Scandinavia and Scotland/Ireland. In
this framework, the subsequent formation of the
symmetrical Greenland–Iceland–Faroe Ridge can be
coherently explained by the continuous supply of hot
plume material through an established channel between
Eastern Greenland and the British Isles. In contrast to the
Scotland/Ireland region, the South Norway continental
lithosphere remains too thick to enable localized uplift of
the topography and melting immediately after plume lobe
emplacement at ~60 Ma. Therefore, the development of
topographic domes in Southern Scandinavia only started
~30 Myr later in the Oligocene because of increasing ridge-
push compression that built up during the opening of the
Norwegian-Greenland Sea.
The evolution of the North Atlantic region shows that a
thermal anomaly that has been hidden below a thick
lithosphere for tens of Myr without signs of excessive
magmatism can be re-initialized (or “re-awakened”) by the
lateral propagation of spreading ridges or by the tapping of
its source beneath thinner segments of the overlying
lithosphere due to horizontal plate movements. We dub
this type of Large Igneous Province (LIP) as LIP-
Dornröschen (LIP-Sleeping Beauty) (Koptev et al., 2021;
Koptev and Cloetingh, 2024). We hypothesise that the
term LIP-Dornröschen may be applicable to a broad
family of LIPs, including Precambrian and oceanic LIPs.
This means that the interpretation of the timing of LIP
formation from the perspective of mantle dynamics should
be treated with caution, as there may be delays between
the timing of upwelling in the mantle and detectable
magmatic manifestations at or near the Earth’s surfac
