Look up: hornfels

1. hornfels
   [n] - a fine-grained metamorphic rock formed by the action of heat on clay rocks
   Found on http://www.webdictionary.co.uk/definitio
   
   
2. hornfels
   (from the article `metamorphic rock`) The hornfels are formed by contact metamorphism and typically show little sign of the action of directed pressure. They are fine-grained rocks in ...
   Found on http://www.britannica.com/eb/a-z/h/70
   
   
3. Hornfels
   Hornfels is a fine-grained metamorphic rock formed mainly from sedimentary rocks and volcanic tuff in zones of contact metamorphism surrounding igneous intrusions, especially granitic masses, at high temperature and extremely high pressures often at great depths within the Earth's crust. Various varieties of
   Found on http://www.probertencyclopaedia.com/brow
   
   
4. hornfels
   Metamorphic rock formed by rocks heated by contact with a hot igneous body. It is fine-grained, brittle, and lacks foliation (a planar structure). Hornfels may contain minerals only formed under conditions of great heat, such as andalusite, Al₂SiO₅, and cordierite, (Mg,Fe)₂Al&...
   Found on http://www.talktalk.co.uk/reference/ency
   
   
5. Hornfels
   `Hornfels` (German, meaning "hornstone," after its frequent association with glacial "horn peaks" in the Alps, being a very hard rock and thus more likely to resist glacial action and form horn-shaped peaks such as Matterhorn) is the group designation for a series of contact meta...
   Found on http://en.wikipedia.org/wiki/Hornfels