noun. In geology, any change in the texture of rocks produced by fracturing and granulation, with recrystallization, whereby rocks become finer-grained and foliated, as the production of gneisses and schists from granites. Chamberlin and Salisbury, 1904.

noun. Any form of metamorphism that occurs near the Earth's surface

noun. metamorphism that occurs at or near the earth's surface; breaks down complex minerals into simpler ones

"The zone in which katamorphism is most active, usually near the surface, is called the _zone of katamorphism_."

zone of katamorphism  

metamorphism