- 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
The coralline Crag is the oldest known of the Crag beds of East Anglia, which have been studied over more than a century relative to the depth of the depositional basin and ecologic and climatic conditions during deposition. Many fossiliferous outcrops are now no longer available, but a new section in Suffolk, on the Butley river southwest of Orford, has been studied recently. It is thought that the previous theory of alternate breaching of land bridges is no longer needed to account for field evidence, and that the "Boytonian zone," proposed by Bell in 1911 to account for a mixed fauna actually does not exist. The Coralline Crag is correlated with the Astian (Pliocene) of the Mediterranean area.