\Plu*ton"ic\, a. [Cf. F. plutonique. See {Pluto}.]
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.
{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}.