metamorphism

metamorphism, in geology, process of change in the structure, texture, or composition of rocks caused by agents of heat, deforming pressure, shearing stress, hot, chemically active fluids, or a combination of these, acting while the rock being changed remains essentially in the solid state. Theoretically, rocks are formed when their constituents are in equilibrium with ambient physical conditions. If the conditions are changed by movements in the earth's crust or by igneous activity, metamorphism occurs to reestablish equilibrium and changes the physical character of the rock mass.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2007, Columbia University Press. All rights reserved.

• • Cite
  • Print
  • Email
  • Bookmark
    • Add bookmark
    • Add to del.icio.us
    • Digg It!
    • Add to Reddit