metamorphic zone
mass of metamorphic rock in which the formation pressure and temperature conditions can be established according to the minerals that compose it
en-GB/ˌmɛtəˈmɔːfɪk ˈzəʊn/
en-US/ˌmɛdəˈmɔɹfɪk ˈzoʊn/
mass of metamorphic rock in which the formation pressure and temperature conditions can be established according to the minerals that compose it