About 20 genera and >30 coral species
5-8 M thick.

Age was Lower Miocene. Revised to latest Oligocene in ref. 2574

Abstract of ref. 1993:
During the middle Tertiary, the island of Jamaica was part of a large system of shallow carbonate platforms extending northeast along the Nicaraguan Rise.
Although these platforms undoubtedly supported a rich fauna of marine benthos, the coral communities of this region are poorly known. New exposures in Jamaica,
however, provide a clearer picture of the development of these Tertiary reefs, especially those spanning the Oligocene/Miocene transition, a time of significant
taxonomic turnover in Caribbean corals. 

Recent bauxite mining on the Manchester Plateau of central Jamaica exposed well-developed (5 - 8 m thick) patch reefs in the Lower Miocene of the Newport
Formation. Sections through these coral build-ups have been logged and extensively sampled. This material was compared with new data from similarly exposed
reefs in the Upper Oligocene Brown's Town Formation of north central Jamaica. Cluster analysis and ordination of coral occurrences has revealed similarities as well
as distinct differences between Oligocene and Miocene assemblages.

Both units contain coral assemblages dominated by massive, branching, or plate-shaped colonies. Coral diversity is also roughly the same in each formation
(approximately 20 genera and >30 species). There is some turnover of species between the late Oligocene and early Miocene, but perhaps the most significant
difference between the sampled assemblages is a change in the relative abundance of certain key taxa. Antiguastrea cellulosa, for instance, is the dominant massive coral in the Upper Oligocene assemblages but is much less common in Lower Miocene faunas.

Ecologically and sedimentologically, there appears to be little difference between the coral build-ups in the Brown's Town and Newport Formations. This suggests
that, in contrast to some other regions in the Caribbean, patch reef communities in Jamaica thrived throughout the Oligocene/Miocene transition. Changes in dominant
coral taxa, however, could suggest a complex shift in community structure during this turnover interval. 