Chapters authored
Late Cenozoic Collisional Volcanism in the Central Part of the Lesser Caucasus (Azerbaijan)
The chapter is devoted to petrogeochemical features of late Cenozoic collision volcanism of the Lesser Caucasus. It was determined that at the early and middle stages of crystallization of the rocks of the andesite-dacite-rhyolite association, amphibole fractionation played an important role in the formation of subsequent differentials. On the basis of computer modeling, it was found that when mixing andesite and rhyolite (taken as a contaminant) magma, it is possible to obtain a rock of dacitic composition. Under conditions of high water pressure, as a result of fractionation of olivine and pyroxene from primary high magnesian magma, high-alumina basalts are formed, which can be considered as the parent magma.Geochemical features of moderately alkaline olivine basalts indicate that the source of magma is metasomaticized, phlogopite-garnet-rutile containing lithospheric mantle. The evolution of moderately alkaline olivine basalts occurs due to changes in the composition of the main rock-forming and accessory minerals. Medium rock formations are formed by the assimilation of poorly differentiated primary magma by an acidic melt. The calculations have shown that proportion of melting rhyolitic melt separated from andesite substrate is close to 15%. After removal of the remaining melt, restite is entirely consistent with the composition of the lower earth crust.
Part of the book: Updates in Volcanology