“…Mantle carbonatite melts with high-alkali contents have been reported by the studies of inclusions in fibrous diamonds (Navon, 1991;Sobolev et al, 1998;Zedgenizov et al, 2004;Hwang et al, 2006;Tomlinson et al, 2006;Klein-BenDavid et al, 2007). High pressure experiments on the partial melting of lithospheric mantle and subducted rocks indicate that near solidus melts of carbonated peridotite (Ghosh et al, 2009;Brey et al, 2011), carbonated eclogite (Dasgupta et al 2004;Yaxley and Brey 2004;Litasov and Ohtani, 2010;Kiseeva et al, 2013), and carbonated pelite Schmidt, 2011a, 2011b) show strong alkali enrichment. Chemical analyses of erupted products from Oldoinyo Lengai volcano also show high alkali content at 15-19 wt% and 4-5 wt% for Na 2 O and K 2 O, respectively (Keller et al, 2010).…”