the world > the earth > structure of the earth > structural features > volcanic formations > [adjective] > volcanic vent
solfataric1885
fumarolic1903
1885 Academy 3 Oct. 225 A legacy of former vulcanicity—the lingering relics of solfataric action.
1895 Physiographic Processes (National Geographic Monogr.) I. 18 This action of hot waters is known as solfataric action, and solfataric waters are quite common in volcanic regions.