On the South-east tip of the Lizard the hornblende schist is "inter-bedded" with pale yellow/green veins and pods of epidosite. These bands can extend laterally for many metres and lie in line with the schistose foliations of the surrounding rock. It is unclear what the provenance of these bands is, but theories include that they are the remains of volcanic ash fall during the deposition of the schist protolith, or the calcic remains of thin beds of ocean floor material deposited during less active periods of emplacement of the protolith.