Agglomerate

The term agglomerate ( Latin: agglomerare - agglomerate, amass ) referred to in petrography a pyroclastic rock consisting of more than 75 % of volcanic bombs.

Definition

The volcanic agglomerate is defined by the components, the grain size and the modal fraction of component size. It consists of more than 75% of volcanic bombs, the rest may also consist lapilli or volcanic ash. Volcanic agglomerates are also often characterized by the absence of a matrix of fine-grained material, so that the rock has a high porosity. Volcanic bombs have a diameter of about 6.4 cm and have rounded shapes, which indicate that the material at the time of ejection was still molten. Are the components when striking the ground still largely molten, so sweat form slag.