Solfataras 100 ° C up to 250 ° C hot fumarole , d. H. Post-volcanic exhalations (discharges) of gases mainly containing hydrogen sulphide (H 2 S), carbon dioxide (CO 2 ) and water vapor. The hydrogen sulfide gives off the unmistakable smell of rotten eggs.
On contact with atmospheric oxygen, the hydrogen sulfide oxidizes and forms elemental sulfur and sulfur dioxide , which dissolves in water and forms sulphurous acid (H 2 SO 3 ). This acid attacks the rock and the soil and, together with the hot water vapor, causes the mineral components to decompose. This decomposition and condensation of water vapor often forms sludge kettles in which the gases escape with the formation of bubbles.
It is named after the solfatara near Pozzuoli in the Phlegraean Fields (Italian Campi Flegrei) west of Naples ( type locality ). The gases are usually spoken of in the plural, the singular is the solfataras .
- S. de Luca: Ricerche sperimentali sulla Solfatara di Pozzuoli, Bibliobazaar, 120 p., ISBN 978-1117495170
- A. de Bylandt-Palstercamp: Théorie de Volcans , Volume 3, Adamant Media Corporation, 474 pp., ISBN 978-0543724984
- Solfatars. Entry in the spectrum lexicon of geosciences.