Variable origin of clinopyroxene megacrysts carried by Cenozoic volcanic rocks from the eastern limb of Central European Volcanic Province (SE Germany and SW Poland)

Clinopyroxene megacrysts occurring in Cenozoic mafic alkaline volcanic rocks from the northern margin of Bohemian Massif (SW Poland, SE Germany) could be subdivided by colour and Mg# (Mg/(Mg + Fe tot )) three groups. Megacryst with highest = 90.0–91.5 (“high Mg#”, HMg#) is transparent strongly Light Rare Earth Element (LREE) depleted contains abundant orthopyroxene lamellae. The clinopyroxene “medium Mg#” (MMg#) values (76.8–83.4) are to light grey all LREE-enriched. group lowest (LMg#; 62.2–74.6) intensively coloured (from green) may enclose apatite, Ti-magnetite or pseudomorphs after amphibole. “low (LMg#) clinopyroxenes LREE-enriched, some display positive Zr–Hf anomalies. single HMg# megacryst records pressures ~1GPa temperature 1280 °C, pointing its mantle origin. It first described European lavas possibly worldwide, which shows affinity Depleted MORB Mantle (DMM). MMg# formed fractionating magmas at variable temperatures – those corresponding depths (>1 GPa, 1230–1350 °C) lower/middle crustal (0.5–0.9 1120–1150 °C). parental melts for this isotopically related Cenozic study area. LMg# crystallized melts, mostly lower- middle-crustal (0.4–1.0 GPa). Their were also volcanism, but their evolved nature resulted local, significant enrichment Zr Hf. localities Poland evidence magmatism north-easternmost part Volcanic Province. • studied. Megacrysts pressure-temperature conditions. intermediate magmas. Most volcanism. Single samples DMM domain