The evolution of refertilized lithospheric mantle beneath the northeastern Siberian craton: Links between mantle metasomatism, thermal state and diamond potential

•The Bulkur garnets derived from the deep subcontinental mantle of northeastern Siberia.•Garnet megacrysts record large-scale melt metasomatism near LAB.•Diamondiferous harzburgites rare due to pervasive melt referzilization.•Refertilized lherzolites and eclogites compose SCLM in the diamond window.•Similar mantle sources of garnets and diamond placers of northeastern Siberia.