- Hacettepe University, Ankara, Türkiye (dihakonder@gmail.com)
Rifting-driven source melting and the origin of the alkaline magmatism located along the active fault segments in Southeastern Mediterranean, Türkiye
Rift-related extensive mafic magmatism was developed along the active segments of the East Anatolian zone in southeastern part of Anatolian lithosphere, since Quaternary times. These mafic and mainly basaltic rocks are widely distributed in Osmaniye - Ceyhan district and along the Karasu valley in Hatay. The mafic lavas from Toprakkale region are predominantly classified as alkaline basalts with SiO₂ and MgO contents ranging from 45.79-48.65 wt% and 7.99-8.88 wt%, respectively. Additionally, one sample is classified as basanite, with a SiO₂ content of 44.18 wt% and MgO content of 6.53 wt%.
The primitive mantle-normalized multi-element diagram exhibit enrichments in LILE relative to HFS elements, and these elemental patterns are similar to that those of OIB source but differ from OIB signature with relatively depleted LILE and HFSE contents. However, the basanite sample distinguishes itself by the enrichment in Nb, Ta, Sr, P and minor depletions in Zr, Hf contents relative to OIB source. The incompatible element ratios Nb/U (27.29-77.55), Nb/La (0.72-1.60), Zr/Ba (0.57-0.70) suggest that basaltic rocks were derived from OIB-like mantle source. The (Tb/Yb)(N) ratios of the lava products span from 1.89 to 2.68 that separates the melting from the Garnet - Spinel ((Tb/Yb)(N) >1.8; [1]) transition zone, accompanied with moderately to high (La/Yb)(N) ratios (9.92-14.37). Besides, Zn/Fe ratios of basaltic rocks range between 10.40-12.41 which separates the peridotite-derived (Zn/Fe <12; [2]) and pyroxenite-derived (Zn/Fe 13-20); [2]) melts.
Rifting process has a key role in magma generation where the stretching lithosphere leads to decompression melting, collectively, all these elemental ratios strongly suggest that basaltic rocks were derived from the melting of peridotite source domains within the region significantly affected by the active fault segments.
1.Wang et al., 2002, J.Geophys.Res.vol:107, ECV 5, 1-21
2.Le Roux, et al.,2011, EPSL, vol:307, 395-408
How to cite: Önder, D. A., Kürkcüoğlu, B., Yürür, M. T., Kahraman, B., and Külahcı, G. D. D.: Rifting-driven source melting and the origin of the alkaline magmatism located along the active fault segments in Southeastern Mediterranean, Türkiye, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-612, https://doi.org/10.5194/egusphere-egu25-612, 2025.
