Coarse-grained volcanic rock with rounded to subangular fragments. These fragments are mainly larger than 2 cm in size, but the mixture of fragments is typically ill sorted and the matrix may be fine grained. An agglomerate may be the product of a volcanic explosion and therefore a pyroclastic rock, but often the term ‘agglomerate’ is applied to brecciated volcanic rocks of uncertain origin. Those deposits may range from vent breccias to debris from mudflow or lahar deposits.