Ichnological analysis of contourites: Past, present and future

Contourite deposits are significant facies in deep-water sedimentary environments because they record critical paleoclimatological and paleoceanographic data. Contourite research also informs slope-stability/geological hazard assessment and petroleum exploration. Scientific consensus has not converged on several key aspects of contourite interpretation however. Some researchers interpret bioturbation as a diagnostic feature that differentiates contourites from associated facies (e.g., turbidites), while other researchers consider bioturbation to be of second order importance. This work reviews existing literature and relevant field data to better define the role of ichnological analysis in contourite research. Review of significant contributions by earlier studies, including formalization of terminology (bioturbation, burrow, etc.) can help constrain wider usage of ichnological concepts (e.g., ichnofacies) and ichnotaxonomic analysis. This paper also revisits ichnological data in paleoenvironmental interpretations, reservoir characterization, and the rare example of ichnofacies and ichnofabric analyses. Designation of diagnostic criteria can promote the use of ichnological information in contourite research. Regardless of consensus concerning bioturbation as a diagnostic criterion in contourite characterization, ichnological data can still inform interpretations and integrate with other techniques to advance understanding of contourite sedimentary facies for a broad range of applications.