phonolite conglomerate

Petrol.: Phonolite fragments with pieces of other rocks inclosed in a pulverulent phonolitic cement. phonolite-tuff, s . Petrol.: An earthy friable deposit, consisting of phonolitic materials with fragments and crystals of sanidine, hornblende, biotite, olivine, magnetite, . phonolite-wacke, s. Petrol.: An amygdaloidal phonolite, which has been altered, so that the ground ma has become quite earthy.