Breche

Breche is a term found in French that denotes a breach, gap, or opening in a barrier such as a wall, cliff, or natural formation. It can also refer to a mountain pass or a narrow gap through a ridge. In place names, the word appears in toponyms that describe geographic features like passes or breaks in terrain.

In geology, brèche (often anglicized as breccia) refers to a rock composed of angular fragments of older rocks held together by a finer-grained matrix. The fragments are typically of different lithologies and sizes, giving the rock a distinctive, fragmental texture. Breccias can form through rapid fragmentation during faulting or landslides, volcanic explosions, or diagenetic processes that cement broken pieces together. They are used by geologists to interpret past deformation, transport directions, and mineralizing events, and may host various ore deposits.

In historical and military contexts, a brèche denotes an artificial or natural opening created to breach defenses or to exploit a weakness in a fortification. The term can describe a gap in a siege line or a passage opened to allow troops or artillery to breach a defensive work.

The term brèche appears in several languages with related meanings tied to openings or fractures. When encountered in English-language geology or archaeology, it is usually linked to the French term and its English counterpart breccia.