Melilite-bearing igneous rocks are known to be derived from the partial melting of dolomitic garnet-bearing lherzolite under CO2-rich conditions at pressures between 27 and 40 kbar. However, there are still unresolved questions regarding their magma evolution. The Vogtland volcanic field is part of the Central European Cenozoic Igneous Province and hosts various olivine melilitite and melilite-bearing olivine-nephelinite diatremes, such as those at Bösenbrunn and Burkhardtsgrün.
The olivine melilitite and melilite-bearing rocks of these two locations are characterized by variable olivine content, often with skeletal or "hopper" morphology. They also contain clinopyroxene, melilite with a typical "pag" structure, magnetite, Cr-spinel, rare nepheline, apatite, zircon, and perovskite. Within some melilitites, the presence of reversely zoned melilite in clinopyroxene-bearing melilitites is probably the consequence of the co-precipitation of melilite with clinopyroxene. As clinopyroxene crystallization initiates, the Al/Mg ratio of the residual melt rises, causing a gradual depletion of åkermanite content from core to rim within the crystallizing melilites. Variations in major and trace elements, along with zoning patterns in coexisting minerals, may be influenced by their affiliation with either Ca-rich or -poor magma series. Trace-element fractionation during differentiation of these parental magmas suggests the existence of two mantle-derived magmas: (i) a melilite-bearing series formed at higher pressures (ca. 35 kbar), which was originally enriched in CO2, Sr, Nb, and REE (La, Ce, etc) and differentiated at shallower depths, while (ii) a Ca-poor magma began fractionating only at around 17 kbar during magma ascent.