Plutonic rocks

Intrusive \In*tru"sive\, a.
   Apt to intrude; characterized by intrusion; entering without
   right or welcome.
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   {Intrusive rocks} (Geol.), rocks which have been forced,
      while in a plastic or melted state, into the cavities or
      between the cracks or layers of other rocks. The term is
      sometimes used as equivalent to {plutonic rocks}. It is
      then contrasted with effusive or volcanic rocks. --
      {In*tru"sive*ly}, adv. -- {In*tru"sive*ness}, n.
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Plutonic \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.
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   2. Of, pertaining to, or designating, the system of the
      Plutonists; igneous; as, the Plutonic theory.
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   {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}.
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