Minor intrusions surround the Ardara diapiric pluton, all of which are associated with intrusion breccias. One of these, a small pluglike body north of Dunmore hill, northwest Ireland, is described here. It is an elliptical intrusion, about 170 by 45 yards, and comprises a marginal breccia surrounding a ring of felsite which in turn encloses a breccia core. The breccia is completely local in character, none of it having travelled more than several yards. The origin is discussed, particularly the role of a gas phase.