Porphyry

(See also: Melaphry, Rhyolite, Terroir, Volcanic, 7 Terroirs)

Although it has often been written that the bedrock in many of the 7 Terroirs or VDP Grosse Lagen / “Grand Crus” of Gut Hermannsberg is porphyry this is not technically correct. It would be better to say that they are volcanic rocks with a porphyritic structure (meaning composed of grains of widely differing size, unlike say granite with its mottled structure of even-sized grains). The most important of these are rhyolite, the bedrock in the Bastei, Rotenberg and Rossel Monopol sites and the melaphry in the Felsenberg and Kupfergrube sites,but there’s also the Lemberg Porphyry of the Steinberg site. The soils that weather from these rocks and all stony and quite acidic with a lot of minerals but low fertility.

g.