Living Reefs and Paleozoic Bioherms

Arthur L. Bowsher

E. R. Cumings and R. R. Shrock applied the term "bioherm" in 1928 to carbonate mounds in the Silurian if Illinois and Indiana. Mississippian bioherms in the Sacramento Mountains of New Mexico were reported by L. R. Laudon and A. L. Bowsher in 1941. P. B. King published his classic study of the Permian Capitan reef in west Texas in 1942.

Coral reefs of the Bahama Islands and Campeche Bank of Mexico are linear thickets of Acropora, a scleractinian coral, growing upward from a shoal bottom lying about 12 ft (3.7 m) below mean low tide. These living reefs of the Atlantic seem only in part to be like the Paleozoic carbonate features.

The atolls of the Palau Islands of the southwest Pacific are very like the Permian Capitan Reef that King described. These broad limestone banks, more than 1 mi (1.6 km) wide, lie near mean low tide. An algal ridge is narrow and relatively weak at the outer edge.

Uplifted Miocene reefs of Palau are bioherms up to 700 ft (213.3 m) thick. These coral-algal limestone mounds are almost identical to some known in the Mississippian of the Sacramento Mountains of New Mexico. Thus, the reefs of Palau serve as models for ancient reefs of the Sacramento Mountains.

AAPG Search and Discovery Article #91034©1988 AAPG Southwest Section, El Paso, Texas, 21-23 February 1988.