Degassing in kimberlite: Oxygen isotope ratios in perovskites from explosive and hypabyssal kimberlites

► O isotopic composition of kimberlitic perovskites is reported for the first time. ► Geochemistry of perovskites from Orapa and Wesselton kimberlites is studied. ► Orapa perovskites have bimodal δ18O distribution while Wesselton δ18O is unimodal. ► Perovskites record the δ18O of uncontaminated mantle derived kimberlite magma. ► Effects of magma degassing during emplacement of kimberlite can also be identified.