regional metamorphism

[rējə-nəl]
  1. A type of metamorphism in which the mineralogy and texture of rocks are changed over a wide area by deep burial and heating associated with the large-scale forces of plate tectonics. In regional metamorphism, rocks that form closer to the margin of the tectonic plates, where the heat and pressure are greatest, often differ in their minerals and texture from those that form farther away. Compare contact metamorphism.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.