Magma chambers beneath the Klyuchevskoy volcanic group (Kamchatka)

The classification of potassium basaltic trachyandesites that were discharged by the 2012–2013 parasitic eruption on Ploskii Tolbachik Volcano, Kamchatka using geochemical criteria

“…A model was proposed for melting of an undepleted mantle source of the lherzolite-harzburg ite series to explain the origin of the parent melts of the Klyuchevskoi moderate potassium magnesian basalts, with the melting being due to the water bearing compo nent of the subducted plate (Khubunaya and Sobolev, 1998). The results that were obtained here suggest that the melt separated from the mantle material at depths of 50-60 km (Khubunaya et al, 2007).…”

“…4). The geochemical and mineralogic features of these rocks have been described in sufficient detail in the appropriate literature (Ermakov and Vazheevskaya, 1973;Khubunaya et al, 1993Khubunaya et al, , 1998Khubunaya et al, , 2007Kersting and Arku lus, 1994;Ariskin et al, 1995;Volynets et al, 1999;Mironov, 2009, among others). All of these rocks possess similar petrographic characteristics, a similar list of rock forming minerals and their compositions, and similar concentrations of major elements and admixture ele ments ( Table 2).…”

“…The olivines are not in equilibrium with the chemical compositions of the rocks where they are found. At the same time, they can be in equilibrium in relation to the compositions of the parent mantle melts (Khubunaya et al, 1993(Khubunaya et al, , 2007 (Sun and McDonough, 1989). Results for compositions (2, 3, 4, 5) are from (Perepelov et al, 2007;Perepelov, 2014); The concentrations of admixture elements in rocks (g/t) were normalized by their concentrations in undepleted mantle after (Sun and McDonough, 1989).…”

Multiscale Seismic Tomography Imaging of Volcanic Complexes

“…The use of approximately equal numbers of P and S phases enables the determination of high quality source locations. Approximately same dataset has already been used by other authors in (Nizkous et al, 2006, Khubunaya et al, 2007 where they report the distribution of P velocity beneath the Kluchevskoy group. We have also performed the inversion for the full dataset and obtained rather similar results as in the previous studies.…”

“…The fissure type eruption of Tolbachik in 1975Tolbachik in -1976 appears to be the largest historical basalt eruption in Kamchatka (e.g., Fedotov et al, 2010). This diversity of composition and eruption regimes in volcanoes at distances of dozens of kilometers from each other shows that their feeding occurs both directly from mantle sources and through complex system of intermediate chambers in the crust (e.g., Khubunaya et al, 2007). Another feature of this region which is very important for tomographic inversion is the major part of seismic energy is released at great depths ( Figure 16B).…”