. "Andesitic pitchstone. Igneous intrusive bedrock. Occurs onshore. Emplaced during the Paleogene Period (66-23.04 Ma BP)."@en . . . "stable"@en . . "23.04"^^ . "Ben Hiant Pitchstone Sheet-Swarm"@en . "BHPI"@en . . "Andesitic pitchstone."@en . . . "66.0"^^ . "Ben Hiant Pitchstone Sheet-Swarm"@en .