BGS Rock Classification Scheme

Ultracataclasite - A type of cataclastic-rock. In the Rock Classification Scheme, it is one in which fragments significantly coarser than the matrix comprise less than 10% by volume of the rock. British Geological Survey Research Report RR/99/02, section 7.2 and table 4.

Code ULCAT
Description Ultracataclasite - A type of cataclastic-rock. In the Rock Classification Scheme, it is one in which fragments significantly coarser than the matrix comprise less than 10% by volume of the rock. British Geological Survey Research Report RR/99/02, section 7.2 and table 4.
Qualifiers No qualifiers currently exist.
Definition Deformed (brittle), unfoliated rock with primary cohesion (protolith unidentifiable) comprising <10% fragments, (porphyroclasts if monomineral), in a finer grained matrix, grain size reduction by mechanical fragmentation +/- recrystallisation of matrix.
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/ULCAT

CAVEAT

"Thumbnail" definitions attached to some of the table entries are an interim attempt to provide simple short descriptions of the "unqualified" rock types presented within the BGS Rock Classification Scheme. Every effort has been made to ensure accuracy and consistency but minor contradictions or omissions might be present. The BGS welcomes any feedback pointing out such minor imperfections and/or providing constructive comment and suggestions for improvement of the definitions. In the first instance such feedback should be directed to Dr Tim McCormick.