Glaser L, Grosche A, Voudouris PC, Haase K (2022)
Publication Type: Journal article
Publication year: 2022
Book Volume: 177
Journal Issue: 8
Genetic models for the formation of K-rich magmas in subduction-related settings range from partial melting of subduction-affected mantle sources to melting of crustal rocks depending on the local tectonic framework. The Miocene high-K calc-alkaline to shoshonitic rocks of Limnos Island reflect the magmatic activity in the northern Aegean, which migrated southwards in response to trench retreat and the collision of continental terranes in the Hellenic subduction system. New whole rock and mineral data of basaltic andesites, dacites and monzonites from Limnos indicate that the magmas underwent fractional crystallization of olivine, clinopyroxene, amphibole, apatite, and Fe-Ti oxides at 1100 to 700 degrees C and 0.5 to 0.1 GPa without significant assimilation of crustal rocks during the magma evolution. The strong enrichment of large ion lithophile elements and light rare-earth elements relative to depleted heavy rare earth and high-field strength elements points towards a mantle source that has been extensively hybridized by subducted sedimentary material. New Sr-Nd-Pb isotope data reveal a distinct isotopic composition of the Limnos rocks with high Pb-207/Pb-204 at low Pb-206/Pb-204 and Nd-143/Nd-144 ratios that is likely related to the subduction of the continental crustal succession of the Apulian block which was subducted prior to the onset of magmatism on Limnos. Partial melting models assuming a hybridized mantle source suggest that the primary melts of Limnos formed by melting of a phlogopite pyroxenite at melting degrees of 5 to 10%. Compositional differences between high-K calc-alkaline and shoshonitic magmas are explained by variable melting degrees and varying amounts of sediment supply to the mantle. The magmatic and tectonic evolution of Limnos island is typical for the Oligocene and Miocene volcanic centres of the migrating western Aegean arc front.
Glaser, L., Grosche, A., Voudouris, P.C., & Haase, K. (2022). The high-K calc-alkaline to shoshonitic volcanism of Limnos, Greece: implications for the geodynamic evolution of the northern Aegean. Contributions To Mineralogy and Petrology, 177(8). https://dx.doi.org/10.1007/s00410-022-01940-7
Glaser, Leon, et al. "The high-K calc-alkaline to shoshonitic volcanism of Limnos, Greece: implications for the geodynamic evolution of the northern Aegean." Contributions To Mineralogy and Petrology 177.8 (2022).