Metasomatism (from the Greek μετά metá "change" and σῶμα sôma "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is traditionally...

alunite, barite, dickite, kaolinite, pyrite and quartz are also found. Propylite-like degradation as well as veins contained inside of rock that has been...

Hydrothermal alteration has given rise to alunite, kaolinite, phengite, propylite and sericite. Potassium-argon (K-Ar) dating of the Miri summit has yielded...

favorable box rocks are metabasalts and metaandesites (green rocks and propylites); Gold is found mainly in the form of native gold in quartz veins and...

Huayna Porco hills, the tuff has been altered to varying degrees, forming propylite and sericite. A number of individual veins of ore rock cross-cut the Porco...