Sublithospheric melt input in cratonic lamproites

Abstract Cratonic lamproites are diamondiferous ultrapotassic rocks that emplaced through thick continental lithosphere and thought to derive from melting of metasomatized (i.e., geochemically enriched) regions the subcontinental lithospheric mantle (SCLM). We explored alternative hypothesis melts sourced sublithospheric convective mantle) sources dominate genesis cratonic lamproites. Supporting evidence includes a robust linear correlation between Mg/Fe ratios xenocrystic magmatic olivine in worldwide, overlapping trend observed for kimberlite olivine. This indicates that, similar kimberlites, primary lamproite originate broadly before assimilating SCLM material variable composition. The also characterized by direct ratio bulk-lamproite K2O/Al2O3, an index potassium enrichment melt is independent mantle-xenocryst entrainment differentiation. Quantitative modeling this results interaction carbonate-bearing phlogopite-rich wall SCLM. Our data show kimberlites have mantle, with acquiring their peculiar K en route surface. Modification during transit might represent common process alkaline mafic/ultramafic magmas.