Contourite facies and cyclicity: a geostatistical approach

The contourite depositional systems can vary widely in both composition and textures. Notable lithofacies changes from muds, through silts and sands then to silts and muds again are typified by the term bi-gradational sequences (sediment cycles). These sequences are described within the contourite depositional systems of Gulf of Cadiz with distribution patterns unique to each stage of the drift evolution.
This research focuses on the cyclicity patterns of the contourite sediments, as expressed by their lithological facies’ changes. Cores from Sites U1386 and U1387 were logged and sampled for their facies and mineralogical characteristics.
Clustering and geostatistical analyses including autocorrelation, cross-correlation and frequency analysis were applied to assess Site-to-Site correlation as well as connection to the Marine Isotope Stages (MIS), wirelog data and downhole magnetic susceptibility measurements. Significant changes to these the contourite cyclicity were triggered by major climatic events, such as warm and cold periods during the past million years.