Similarly to conglomerate, breccias are siliciclastic rocks comprised of a framework of clasts (>2 mm)within a finer-grained matrix. Conglomerates and breccias are distinguished apart based on the angularity/roundness of the clasts in which breccias are characteristically angular with much sharper edges rather than smooth like that of a conglomerate (see Conglomerates samples). This sample can be classified as an oligomictic orthobreccia due to its grain-supported matrix of angular, pebble-sized (4-64 mm in diameter) chert clasts within a very fine-grained mud infill. The red colour of the matrix may be due to the presence of ferric oxides and could be indicative of depositional or transport environments.