Chapter 13 Contourite Facies and the Facies Model

Abstract

This chapter reviews the historical context and describes the different contourite facies recognized. The contourite facies models are outlined and the interpretation of contourite sequences is discussed. Some hybrid contourite facies are considered and criteria for the distinction between contourites and associated facies in deep-water systems are focused on. The problems and controversy surrounding the recognition of fossil contourites in the ancient records arealso described. The range of recognized contourite facies, including the facies groups, are tabulated. . Muddy contourites are homogeneous and appear as thick featureless units. Silty contourites have a larger silt-sized component and potential for revealing some internal structure. Gravel-rich contourites and gravel-bearing contourites are common in drifts at high latitudes as a result of input from ice-rafted material. The facies models for both muddy and sandy contourites are originally based on data from many examples of contourites. Composite contourite facies model showing grain-size variation through the standard mud-silt-sand contourite sequence, linked to variation in contour-current velocity is diagrammatically represented.