[met-uh-soh-muh-tiz-uh
m] 
| 1. | the series of metamorphic processes whereby chemical changes occur in minerals or rocks as a result of the introduction of material, often in hot aqueous solutions, from external sources. |
| 2. | replacement (def. 4). |
| met·a·so·ma·tism (mět'ə-sō'mə-tĭz'əm) n. The process by which the chemical composition of a rock is changed by interaction with fluids; replacement of one mineral by another without melting. met'a·so·mat'ic (-māt'ĭk) adj., met'a·so·mat'i·cal·ly adv. |
| metasomatism (mět'ə-sō'mə-tĭz'əm) also metasomatosis (mět'ə-sō'mə-tĭz'əm) Pronunciation Key
The process by which the chemical composition of a rock is changed through the introduction or extraction of chemicals dissolved in fluids that migrate through the rock's pores. Metasomatism often results in the formation of new minerals, especially metal ore deposits. |