Sedimentary rocks can form both directly during eruptions and the destruction of effusive rocks. They can inherit the geochemical features of parent rocks. Therefore, the study of trace elements of the effusives is significant for the interpretation of the erosion source. This work provides information about trace element geochemistry of basalts from Vesuvius and Batur volcanoes, which are located at different ends of the Mediterranean-Alpine-Himalayan folded belt and represented by alkaline (subalkaline) type of magmas. The comparison of trace element concentration obtained by atomic emission spectral analysis and inductively coupled plasma mass spectrometry showed strong differences for a number of elements. Magma of Vesuvius, originating from a deep source, assimilated in its path the core material, which led to the eruption of lavas of the type EM I with high concentrations of Ba, Be, Cs, La, Rb, Mo, U, W, Zr. Batur relates to subduction arc volcanoes with the characteristic type of lavas HIMU, which are depleted of listed above chemical elements and enriched Bi. The basalts of these volcanoes have similar anomalies of the geochemical composition for most trace elements, suggesting that they have one close source that can be presented by subduction-modified oceanic lithosphere involved in generation of both HIMU and EM types.

In areas of active volcanic activity, sedimentary rocks can form both directly during eruptions and the destruction of effusive rocks. Therefore, the study of effusive parent rocks such as basalts is very important. This work provides information about the history of formation and geological structure of Vesuvius and Batur volcanoes, which are located at different ends of the Mediterranean-Alpine-Himalayan folded belt and have a similar layer-cone structure and they are represented by alkaline (subalkaline) type of magmas. Based on the research and literature data, it is found that modern basaltic samples from these volcanoes are mineralogically close. The basalt of Mount Batur was formed from lavas with higher aluminium content in the melt, higher viscosity, with strong degassing and rapid cooling. The formation of effusive rocks of Vesuvius, on the contrary, is associated with a lower viscosity of lava, a lower content of aluminium and its slower cooling. They underwent more significant secondary changes.