What is a breccia in geology ?
Breccia : definition
This term is borrowed from the Italian breccia (broken stone), it designates a rock formed by more than 50% of angular fragments of a dimension greater than 2 mm, assembled by a cement. The brecciais said to be "monogenic" if all the elements which compose it are of the same nature and "polygenic" in the contrary case. A micro-breccia denotes a breccia formed of elements from 64 µm to 2 mm. Breccias can be of very varied origin : sedimentary, volcanic, plutonic, tectonic, hydrothermal...