Modern areas of carbonate deposition illustrate the distribution of carbonate facies within an overall depositional setting, and therefore can play an integral part in a subsurface geological model by indicating the dimensions, trend, and interrelationships of facies that might be related to reservoir and non-reservoir distribution. Several modern carbonate areas depict the geological characteristics that can be expected in ancient reef settings like those of the Devonian in the Western Canada Sedimentary Basin. The generalized styles of reefs shown by the various modern areas are: Rimmed shelf/platform margin reefs - South Florida, Bahamas, Caicos Platform in the British West Indies, Belize, and the Great Barrier Reef of Australia Smaller isolated reefs within shallow shelves and lagoons (South Florida, the Bahamas, and Caicos) or broad, deep shelves and lagoons (Belize and the Great Barrier Reef) Isolated carbonate platforms or banks separated by deep water - Chinchorro Bank offshore of Yucatan, and the offshore Belize platforms The geological framework and distribution of reef facies as illustrated by these modern areas can be important in the development scale analysis of ancient reservoirs where reservoir quality is tied to facies changes and facies dimensions are required as input to reservoir models. The geological framework is also important at the exploration scale for reservoir facies prediction and stratigraphic play concepts which are related directly to depositional facies patterns.