Diagenetic priming of submarine landslides in ooze-rich substrates

Abstract

Oozes are the most widespread deep-sea sediment in the global ocean, but very little is known about how changes in their physical properties during burial impact slope stability and related geohazards. We used three-dimensional seismic reflection, geochemical, and petrophysical data acquired both within and adjacent to 13 large (in total ~6330 km2) submarine slides on the Exmouth Plateau, North West Shelf, Australia, to investigate how the pre-slide physical properties of oozes control slope failure and emplacement processes. Our integrated data set allows potential slide surfaces to be detected within ooze successions, a crucial advance for improved submarine geohazard assessment. Moreover, we demonstrate that the interplay of tectonics, ocean current activity, and silica diagenesis can prime multiple slides on very low-gradient slopes in tropical oceanic basins. Therefore, the diagenetic state of silica-rich sediments should be considered in future studies to improve slope stability assessments.