- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
"Published descriptions and new field observations in Ireland and Canada confirm that strain-slip cleavage should not be classified with fracture cleavage. The term crenulation cleavage is proposed to replace the generic one of strain-slip cleavage. Crenulation cleavage differs essentially from slaty and fracture cleavage in that it only develops in laminated rocks and is consequently nearly always a secondary structure. Intense metamorphism converts crenulation cleavage into a new schistosity or cleavage with characteristics similar to slaty cleavage. Two fundamentally different types are recognized and it is suggested that crenulation cleavage is a valuable indicator of metamorphic conditions during the various phases of deformation."