Vesicles and related structures in lavas

A review of certain late-stage textures in subaerial, submarine and lunar extrusive rocks is presented, together with a genetic classification of vesicles. The term paravesicle is introduced for hollows in lavas caused by the introduction of a gaseous phase into the lava after extrusion. Examples taken from the andesitic lavas of the Borrowdale Volcanic Series are used to illustrate the usefulness of studying such features.