Identifying time constraints and mechanisms of crust-mantle coupling in Central European continental lithosphere
Final Report Abstract
Although the original plan of the project did not work out for several reasons we believe that the project was successful and yielded several important new results: 1. The subcontinental lithospheric mantle beneath the Eger Rift is strongly depleted unlike most regions studied in the Earth's post-Archean lithosphere. 2. The subcontinental lithospheric mantle in Central Europe shows significant variation in its depletion that may be related to the different evolution of the Variscan terranes and thus not only the crust may differ but also the underlying mantle. 3. The youngest volcanism of the Eger Rift shows a complex magma formation and evolution by partial melting of metasomatized lithospheric mantle and polybaric crystallization during the ascent. 4. The depths of crystallization of the Quaternary magmas from the western Eger Rift agree with the depths of recent eartquake swarms and thus the seismic activity may be related to crustal magma reservoirs. 5. The lavas of the off-axis Loucna-Oberwiesenthal volcanic centre are significantly more enriched in some incompatible elements than those from the 20 km distant onaxis Doupovske hory volcanic complex suggesting different melting zones for the two neighbouring regions. 6. The magma evolution of the off- and on-axis magmas differs and thus the tectonic situation of the magma systems appears to play an importnat role for the depths of magma stagnation. 7. The composition of amphibole and apatite may yield insights into the magma evolution and the effects of magma differentiation on F and Cl contents.
Publications
- Magmatic Evidence for Carbonate Metasomatism in the Lithospheric Mantle underneath the Ohře (Eger) Rift. Journal of Petrology Volume 56, Issue 9, 1 September 2015, Pages 1743–1774
Brandl, P.A., F.S. Genske, C. Beier, K.M. Haase, P. Sprung, and S.H. Krumm
(See online at https://doi.org/10.1093/petrology/egv052)
