Publication details
Chemistry and Sr–Nd isotope signature of amphiboles of the magnesio-hastingsite-pargasite-kaersutite series in Cenozoic volcanic rocks: Insight into lithospheric mantle beneath the Bohemian Massif
| Authors | |
|---|---|
| Year of publication | 2018 |
| Type | Article in Periodical |
| Magazine / Source | Lithos |
| MU Faculty or unit | |
| Citation | |
| Web | ScienceDirect |
| Doi | http://dx.doi.org/10.1016/j.lithos.2018.05.017 |
| Keywords | Bohemian Massif; Cenozoic volcanic rocks; Ti-amphibole; Sr–Nd isotopes; Mantle metasomatism |
| Attached files | |
| Description | Amphibole phenocrysts and xenocrysts from Cenozoic volcanic rocks of the Bohemian Massif (BM) belong to the magnesio-hastingsite-pargasite-kaersutite series. Their host rocks are mostly basaltic lavas, dykes and breccia pipe fills, less commonly also felsic rocks from rift zones along lithospheric block boundaries of the BM. The calculated p–T conditions suggest that almost all amphiboles crystallized in a relatively narrow temperature range (1020–1100 °C) at depths of 20–45 km (0.7–1.2 GPa) during the magma ascent. The initial 143Nd/144Nd and 87Sr/86Sr ratios of amphiboles (0.51266–0.51281 and 0.70328–0.70407, respectively) are similar to those of their whole rocks (0.51266–0.51288 and 0.70341–0.70462, respectively). This testifies to locally elevated proportions of recycled Variscan crustal material during melting of mantle peridotites rich in clinopyroxene–amphibole veins. These veins were formed by metasomatic fluids enriched in High Field Strength Elements and are isotopically similar to EM-1 mantle type. |