Level Mountain has experienced volcanic eruptions sporadically for the last 15 million years, making it the most persistent volcano of the NCVP. More than 20 eruptive centres are present on the summit and flanks of the complex. These have produced mainly felsic and mafic lavas, a chemical composition range typical of bimodal volcanism. Such volcanism commonly occurs at hotspots, continental rifts and leaky transform faults. The existence of olivine, orthopyroxene and spinel xenocrysts in Level Mountain basalt suggest that volcanism at the complex originated from the upper mantle. Hiatuses of up to a million years or more can be expected between periods of volcanic activity at Level Mountain.