Worlds of David Darling
Encyclopedia of Science
   
Home > Encyclopedia of Science

laccolith





active and ancient volcanic features
Active and ancient volcanic features, including laccolith
A dome-like intrusion of igneous rock, usually arching the overlying strata and with an approximately flat base. They are generally less than 16 km (10 miles) in diameter with thickness of 30–900 m (100–3,000 ft). Laccoliths are formed of magma; they are smaller than batholiths.

Phacoliths are similar but lens-shaped, with a concave side facing downward and a convex side facing upward. See also dike and sill.


Related category

   • GEOLOGY AND PLANETARY SCIENCE