Breccia consists of broken, sharp-edged rock fragments embedded in a finer-grained matrix or mineral cement. Unlike conglomerate, which contains rounded clasts, the angular pieces in breccia indicate that the material was deposited close to its source without significant transport. In mining, fault breccias are highly significant because their high porosity often traps valuable hydrothermal mineral deposits.
Heard on the job
The core sample shows a heavily mineralized fault breccia with visible copper sulfides in the matrix.