Plutonic

a.
  1. Of or pertaining to Pluto; Plutonian; hence, pertaining to the interior of the earth; subterranean.
  2. Of, pertaining to, or designating, the system of the Plutonists; igneous; as, the Plutonic theory.
    3. Plutonic action (Geol.),
    the influence of volcanic heat and other subterranean forces under pressure.
    Plutonic rocks (Geol.),
    granite, porphyry, and some other igneous rocks, supposed to have consolidated from a melted state at a great depth from the surface. Cf. Intrusive rocks, under Intrusive.
    Plutonic theory . (Geol.)
    See Plutonism.