Matusiak-Malek M., Puziewicz J., Ntaflos T., Grégoire Michel, Benoit M., Klugel A. (2014). Two contrasting lithologies in off-rift subcontinental lithospheric mantle beneath central Europe-the Krzeniow (SW Poland) case study. Journal of Petrology, 55 (9), p. 1799-1828. ISSN 0022-3530.
Titre du document
Two contrasting lithologies in off-rift subcontinental lithospheric mantle beneath central Europe-the Krzeniow (SW Poland) case study
Matusiak-Malek M., Puziewicz J., Ntaflos T., Grégoire Michel, Benoit M., Klugel A.
Source
Journal of Petrology, 2014,
55 (9), p. 1799-1828 ISSN 0022-3530
Miocene basanite from Krzeniów (SW Poland, eastern part of CenKoic Central European Volcanic Province) contains scarce, small (usually <4 cm in diameter) spinel harzburgite and dunite mantle xenoliths. Woo groups are &fined based on the forsterite (Pb) content in olivine: group A (F0,90.4- 91.7) and group B bo88.0 89.8). Both group A and B rocks are either clinopyroxenefree or clinopyroxene-poor. The group A o)thoproxene (mg 0-91 0 92) is Al-poor and strongly light To-6 earth element (TREE) depleted The mg of group A clinop.yroxene varies from 0.92 to 0.94 and is negatively correlated with its Al content. The trace element compositions of clinopyroxene define two patterns: Al, U-shaped 1(La/Lu), almost linear LREE enriched [La/Lu)N=11.91-14.001. The group B orthopyroxene is also Al poor and LREE depleted /La/La) N = 0-030-047 but its mg is lower than that in group A orthopyrovene (0-900-92). 'The mg of group B clinopyrovene (0-900-927 is lower than that in group A, whereas the Al content is similar. The REE patterns of group 13 clinopyroxene mimic those of subgroup, N=5.64-11.5'07. The,youp A harzhargites and dunites represent spina:facies lilltospheric mantle that underwent metasumatism by CO,-bearing silicate melts subjected to chromalogn ic fractionation. Locally (arbor tile silicale immiscible melts were generated. The peridotites in the distal parts of the chromatographic system We're little affected by metasomatism and preserve much of their pre-metasomatic, depleted characteristics. The group B rocks are similar to those of group A except for the lower mg of orthopyroxene and olivine. They were age cted by percolating alkaline silicate melt unders-aturated in clinopyroxene which lowered the mg of the olivine and orthopyroxene (Fe metasomatism'). The A and B peridotites are representative of the Miocene lithospheric mantle close to the malgins of the neighbouring Eger Rift.
Plan de classement
Géologie et formations superficielles [064]
;
Géophysique interne [066]
