Depleted subcontinental lithospheric mantle and its tholeiitic melt metasomatism beneath NE termination of the Eger Rift (Europe)
- Author(s)
- Anna Kukula, Jacek Puziewicz, Magdalena Matusiak-Malek, Theodoros Ntaflos, Joerg Buechner, Olaf Tietz
- Abstract
The ca. 30 Ma Steinberg basanite occurs at the NE termination of the Eger (Ohře) Rift in the NW Bohemian Massif, Central Europe, and belongs to the Cenozoic alkaline Central European Volcanic Province. The basanite hosts a suite of mantle xenoliths, most of which are harzburgites containing relatively magnesian olivine (Fo 90.5–91.6) and Al-poor (0.04–0.13 a pfu) orthopyroxene (mg# 0.90–0.92). Some of these harzburgites also contain volumetrically minor clinopyroxene (mg# 0.92–0.95, Al 0.03–0.13 a pfu) and have U-shaped LREE-enriched REE patterns. The Steinberg harzburgites are typical for the Lower Silesian - Upper Lusatian domain of the European subcontinental lithospheric mantle. They represent residual mantle that has undergone extensive partial melting and was subsequently affected by mantle metasomatism by mixed carbonatite-silicate melts. The Steinberg xenolith suite comprises also dunitic xenoliths affected by metasomatism by melt similar to the host basanite, which lowered the Fo content in olivine to 87.6 %. This metasomatism happened shortly before xenolith entrainment in the erupting lava. One of the xenoliths is a wehrlite (olivine Fo 73 %, clinopyroxene mg# 0.83–0.85, subordinate orthopyroxene mg# 0.76–0.77). Its clinopyroxene REE pattern is flat and slightly LREE-depleted. This wehrlite is considered to be a tholeiitic cumulate. One of the studied harzburgites contains clinopyroxene with similar trace element contents to those in wehrlite. This type of clinopyroxene records percolation of tholeiitic melt through harzburgite. The tholeiitic melt might be similar to Cenozoic continental tholeiites occurring in the Central European Volcanic Province (e.g., Vogelsberg, Germany).
- Organisation(s)
- Department of Lithospheric Research
- External organisation(s)
- University of Wrocław, Senckenberg Museum für Naturkunde Görlitz
- Journal
- Mineralogy and Petrology
- Volume
- 109
- Pages
- 761-787
- No. of pages
- 27
- ISSN
- 0930-0708
- DOI
- https://doi.org/10.1007/s00710-015-0405-3
- Publication date
- 12-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105105 Geochemistry, 105120 Petrology
- Keywords
- ASJC Scopus subject areas
- Geochemistry and Petrology, Geophysics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/depleted-subcontinental-lithospheric-mantle-and-its-tholeiitic-melt-metasomatism-beneath-ne-termination-of-the-eger-rift-europe(80d11fa3-0930-4940-811d-fa10514feab3).html