plutonic

The mountain itself bears the most indubitable marks of plutonic origin.

Down to a comparatively recent period, it would seem to have been the theatre of plutonic phenomena of an extraordinary character.

The name Plutonic or Massive rocks is, however, now almost universally substituted for that of Primary.

Igneous rocks in great variety and in all forms incident to an extruded or volcanic and intruded or plutonic origin are present.

The intrusion may be essentially laccolitic in character, or it may represent the plutonic basis of a volcano.