Abstract
The geological literature states that fossil reefs are found in many parts of the world. Many reefs are reported from the Paleozoic era which includes the Silurian and Devonian periods. The fossil reefs of the Great Lakes region in Silurian and Devonian rocks have been studied fairly intensively for about 60 years. These Great Lakes reefs are composed of a central mound or core of massive dolostone (Silurian) or limestone (Devonian), surrounded by flank beds which dip away from the central core. The cores may be a few feet to many hundreds of feet across. Parts of such reef complexes can be observed in limestone quarries, roadcuts, and outcrops.