Postvolcanic Processes

the combined metallogenic processes that occur after the extrusion of lava or emplacement of magma in a rock mass. The most important agents of postvolcanic processes are thermal waters and gases that separate from the magma and surface waters that have been heated by the magma. Postvolcanic processes include alunitization, zeolitization, chloritization, and opalization, which lead to the formation of various types of altered rocks, such as opal-alunite and zeolitecarbonate-chlorite. Volcanic phenomena such as fumaroles, solfataras, mofettes, and hot springs in the vicinity of volcanoes are also related to postvolcanic processes.