[surfer]

been degassing for years...

http://www.geochemsoc.org/publications/geochemicalnews/gn134jan08/goldschmidt2007excursionth.htm

[Mike Darancette]

A visit to the Laacher See volcano is incomplete without descending down a stair case tunnel ( <120 steps) to the ancient underground excavations of the Mendig lava flow (a tephrite), which were used for the production of millstones since Roman times. More recently, the cellars were utilized by breweries, one of which still produces a delicious "Volcano Beer". The day ended cheerfully with beers and food in the patio of the brewery.

Field work can be a bitch!