Publication Date:
2023-01-31
Description:
The upper crust of central Europe preserves a mosaic of tectonic blocks brought together by the Caledonian and Variscan Orogenies. The lower crust, in contrast, appears to have undergone extensive reworking: the flat Moho across broad areas and the absence of contrasts in seismic properties across tectonic boundaries suggest that the Moho and lower crust are, effectively, younger than the upper crust. The evolution of the mantle lithosphere below the Moho has been particularly difficult to constrain. In this paper, we use seismic, geological and geochemical evidence to show that central Europe's mantle lithosphere has evolved continuously throughout the Mesozoic and Cenozoic Eras, with episodes of lithospheric thinning causing surface uplift and volcanism and lithospheric thickening - subsidence and sedimentation. High-resolution surface wave tomography reveals a strong spatial correlation between locations of recent basaltic volcanism and currently thin lithosphere. We infer that intraplate volcanism further back in the geological past is also an indication of lithospheric thinning at the time. The north-central Europe's lithosphere was, thus, thinned at the time of the Permian volcanism, with its subsequent, Post-Permian cooling and thickening causing the subsidence and sedimentation in the North German and neighboring basins. This explains the presence of Permian volcanics atop presently thickened lithosphere. South of these basins, lithospheric thinning (evidenced by seismic data) is associated with the volcanism of the Central European Cenozoic Igneous Province and surface uplift. Thin lithosphere here also correlates spatially with high melting rates, high silica contents, high temperatures and shallow magma generation. This synthesis highlights the dynamic nature of the lithosphere-asthenosphere boundary beneath central Europe and, more generally, Phanerozoic continents. The boundary's depth varies in time; its deepening (lithospheric cooling and thickening) causes subsidence and sedimentation; its shallowing (lithospheric thinning by thermal erosion or delamination) is marked with uplift and intraplate volcanism.
Type:
Article
,
PeerReviewed
Format:
text
Permalink
