Morphometric signature of sediment particles reveals the source and emplacement mechanisms of submarine landslides

Abstract

The long travel distances recorded by most submarine landslides indicate that changes in particle attributes (shape and size) may occur during their movement. Yet, little is known about the magnitude of such changes, and their underlying physical drivers. In order to understand the failure characteristics of submarine landslides, a dynamic image analyzer was used to characterize the particle size(s), aspect ratio, sphericity and convexity of 200 samples recovered from two IODP sites (C0018 and C0021) offshore Nankai (SE Japan). The two IODP sites drilled a series of submarine landslides, and undisturbed slope sediment, previously characterized in detail on 3D seismic data. The results of this work reveal no perceptive differences for particle size and shape between landslide and undisturbed slope strata, suggesting that remobilized sediment, sourced from marine deposits accumulated on the upper slope of Nankai do not change through slope instability. This lack of particle attribute differences between remobilized (landslide) and undisturbed sediment, and between the two IODP Sites, suggests limited interaction between particles during their movement. A fluidization mechanism is therefore proposed whereby the soft and saturated state of deep-sea sediment leads to the development of excess pore water pressure. This mechanism maintains movement and inhibits particle-to-particle contact, limiting subsequent particle shape and size variations in the failed sediment.

Shelf-derived mass-transport deposits: origin and significance in the stratigraphic development of trench-slope basins

“…This process may explain why abrasion values compare well in the various size fractions of lithofacies DF. In contrast, the abundance of silty mudstone matrix and the low siliciclastic content in lithofacies MF, hence reducing en masse friction between grains and making crushing unlikely (e.g., Li et al 2019), may explain their limited abrasion and could indicate that abrasion and fragmentation were inherited.…”

Study on the geometry characteristics of soil primary mineral particles under cryogenic action

“…The shape and surface texture of the particles are closely related to the geological environment. As described in the introduction to the text, the shape and surface texture of the particles provide vital information regarding the origin, transport and deposition history [5][6][7][8][9][10][11] . In aeolian environment, there are three ways soil particles are moved by wind: surface creep, saltation, and suspension 15,[27][28][29] .…”

“…The freezing and thawing process will not only change the size of soil particles and affect the distribution of grain size, but also change the particle's shape. The particle's shape and surface texture provide vital information regarding the origin, transport and deposition history [5][6][7][8][9][10][11] . The initial shape of particles depends on rock parent material and weathering, and the final shape depends on the transport medium and transport mode.…”

Innovative Approaches for the Sedimentological Characterization of Fine Natural and Anthropogenic Sediments in Karst Systems: The Case of the Apuan Alps (Central Italy)

“…The morphometric analysis is presented only for particles falling in the fine to coarse silt size interval (0.0625 -0.0078 mm, ϕ = 4 -7). This specific grain size interval was selected because it comprises a considerable proportion of particles for all the samples in terms of both volume and number of grains, and because the analysis in narrow size intervals is more helpful for revealing characteristics for these kinds of material (Leibrandt and Le Pennec, 2015;Li et al, 2019). Grain size distributions (GSD) were calculated in volume fractions (V%) and in number of particles (n%) falling in CED intervals of 1 /2 ϕ (Folk and Ward, 1957;Blott and Pye, 2012).…”