Growth history of shallow-water carbonates: control of accommodation on ecological and depositional processes

We explore the role played on the growth of shallow-water carbonates by cha nges in accommodation using case studies from Late Quaternary to modern car bonate environments, i.e. coral reefs and carbonate platforms and ramps. Ac commodation appears not to influence either primary productivity or communi ty structure (K- versus r-strategists) as these are directly governed by nu trient supply; but it does control submarine depositional profiles and thei r stratigraphic expression (i.e. volumetric sedimentary partitioning). The growth of communities from incipient to senescent stages is dictated by rel ative rates of sea-level variations, although ambient temperatures and trop hic conditions may modify the community response. A decrease or stabilizati on of accommodation favours lateral migration, thus generating ecological a nd sedimentary innovations. Organic carbon production tends to be positivel y correlated to that of carbonate, both declining as accommodation decrease s. Shallow water carbonates develop as a result of the interplay of factors , including the types and rates of biological and physical processes. Apply ing depositional models of Recent shallow-water carbonates to the interpret ation of ancient carbonate platforms first needs to acknowledge the respect ive role of the two contrasting phases that operated during the post-glacia l sea-level rise (an earlier, fast-rising phase versus a later, slowly risi ng to stabilizing phase); the period of relative sea-level stabilization (i .e. the past 6,000 years) appears a relevant reference for still-stand-rela ted carbonate systems. Furthermore, the oligotrophic nutrient model, a domi nant feature of the modern shallow-water tropics, can be used as an analogu e in reconstructing carbonate growth histories during greenhouse episodes o f Earth history.