Carbonates Versus Siliciclastics in Sequence Stratigraphy
In chapter 4 we concluded that sea level fluctuations are but one of several ways to generate sequences and systems tracts. This claim is based on a sedimentologic evaluation of sequence anatomy. Where sea level does exert the dominant control on sequence stratigraphy, sedimentology must be called upon again, this time to assess the differences of the sea-level records of depositional systems. Siliciclastics and carbonates are the two most prominent examples that come to mind, but evaporites, too, have their specific ways of recording sea level. Depositional systems resemble newspapers that all report on the events of the day, but each with different editorial bias. It behooves the reader to learn about the editorial bias of his paper. Similarly, the geologist ought to know about the bias of depositional systems in recording changes of sea level (and other environmental factors). Below, we discuss some peculiarities of carbonates vis a vis siliciclastics.
Figures & Tables
Sedimentology and Sequence Stratigraphy of Reefs and Carbonate Platforms: A Short Course
Classical sequence stratigraphy has been developed primarily from siliciclastic systems. Application of the concept to carbonates has not been as straightforward as expected even though the basic tenets of sequence stratigraphy are supposed to be applicable to all depositional systems. Rather than force carbonate platforms into the straightjacket of a concept derived from another sediment family, this publication takes a different tack, starting out from the premise that sequence stratigraphy is a modern and sophisticated version of lithostratigraphy. It reviews sedimentologic principles governing the large-scale anatomy of reefs and platforms; looks at sequences and systems tracts from a sedimentologic point of view; assesses the differences between siliciclastics and carbonates in their response to sea level; evaluates processes that compete with sea level for control on carbonate sequences; and presents a set of guidelines for application of sequence stratigraphy to reefs and carbonate platforms.