Comparison between compositions of phlogopite in the Bultfontein kimberlite and mantle xenoliths.

Kimberlite phlogopite macrocrysts show multiple concentric zoning with cores derived from disaggregation of mantle xenoliths.

Distinct pulses of kimberlite magma crystallize the macrocryst inner and outer rims in the mantle and crust.

Kimberlite ascent requires metasomatism of mantle wall rocks.

Mantle-derived phlogopite antecrysts are common in the kimberlite groundmass.