ABSTRACT

Syndepositional marine cementation on carbonate platforms is a fundamental process that results in physical stabilization and lithification of sediments, as well as reduction in primary porosity and permeability which may affect the migration of later diagenetic fluids. Rapid submarine cementation is commonly invoked to explain various aspects of carbonate platform geometry, especially related to the preservation of steep slopes, but the rates typically reported for cementation in deeper parts of the platform are mostly conjectural. In an attempt to quantify the rates of syndepositional cementation in marginal platform environments, substrates containing samples of carbonate sand (ooids) suspended above the sea floor were emplaced at various depths across a modern platform in the Bahamas to evaluate the rates of cement growth through direct observation. Initial results indicate that cementation may lead to partial lithification of carbonate sands within a minimum of 8 months in water depths of up to 60 m. These results provide some of the first direct evidence for rates at which cementation can occur in deeper marginal environments, and confirms earlier hypotheses that very rapid, syndepositional marine cementation may not be limited to very shallow subtidal and intertidal environments.