Abstract
This paper represents the first report on the peridotitic mantle xenoliths including spinel harzburgites and spinel lherzolites found in the Late Miocene-Pliocene basaltic rocks (Thracean alkaline basalts - TAB) of the Thrace region, northwestern Turkey. The lavas formed and extruded during the north-south extension of western Anatolia, are olivine basalts and basanites displaying within-plate affinity. The estimated modal mineralogy of the peridotite xenoliths is olivine (58-84 %) + orthopyroxene (12-35 %) + clinopyroxene (0-12 %) + spinel (1-5 %). They are characterized mainly by protogranular and also transitional protogranular to porphyroclastic and fine-grained equigranular textures. Melt pockets are recognized in only one sample. Deformation features in olivine and pyroxenes are zoning, twinning, including inclusions, kink banding, triple junction and undulatory extinction. Bulk-rock analyses indicate that the xenoliths are depleted in basaltic components (e.g. CaO - 0.39-1.50 wt. %, Al2O3 - 0.80 - 1.78 wt. %). Light rare-earth element (LREE) enrichment is significant (e.g. Lan 2-6), which suggests a cryptic metasomatic history.
Original language | English |
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Pages (from-to) | 359-368 |
Number of pages | 10 |
Journal | Geologica Carpathica |
Volume | 56 |
Issue number | 4 |
Publication status | Published - Aug 2005 |
Keywords
- Alkali basalt
- Geochemistry
- Mantle
- Northwestern Turkey
- Peridotite
- Petrology
- Xenolith