i. A
breccia with fine grained
clasts, difficult to identify by eye.
ii. A breccia within fragments of a coarser breccia.
iii. A well-indurated, massive rock that has been crushed to very fine grain size through cataclastic flow, commonly in detachment faults.
iv. A poorly sorted sandstone containing large angular particles of sand set in a fine silty or clayey matrix; e.g., a graywacke. It is somewhat less micaceous than a siltstone.
Ref: AGI