Skip to main content

Research Repository

Advanced Search

Froude supercritical flow processes and sedimentary structures:New insights from experiments with a wide range of grain sizes

Ono, Kenya; Plink‐Björklund, Piret; Eggenhuisen, Joris T.; Cartigny, Matthieu J.B.

Froude supercritical flow processes and sedimentary structures:New insights from experiments with a wide range of grain sizes Thumbnail


Authors

Kenya Ono

Piret Plink‐Björklund

Joris T. Eggenhuisen



Abstract

Recognition of Froude supercritical flow deposits in environments that range from rivers to the ocean floor has triggered a surge of interest in their flow processes, bedforms and sedimentary structures. Interpreting these supercritical flow deposits is especially important because they often represent the most powerful flows in the geological record. Insights from experiments are key to reconstruct palaeo‐flow processes from the sedimentary record. So far, all experimentally produced supercritical flow deposits are of a narrow grain‐size range (fine to medium sand), while deposits in the rock record often consist of a much wider grain‐size distribution. This paper presents results of supercritical‐flow experiments with a grain‐size distribution from clay to gravel. These experiments show that cyclic step instabilities can produce more complex and a larger variety of sedimentary structures than the previously suggested backsets and ‘scour and fill’ structures. The sedimentary structures are composed of irregular lenses, mounds and wedges with backsets and foresets, as well as undulating planar to low‐angle upstream and downstream dipping laminae. The experiments also demonstrate that the Froude number is not the only control on the sedimentary structures formed by supercritical‐flow processes. Additional controls include the size and migration rate of the hydraulic jump and the substrate cohesion. This study further demonstrates that Froude supercritical flow promotes suspension transport of all grain sizes, including gravels. Surprisingly, it was observed that all grain sizes were rapidly deposited just downstream of hydraulic jumps, including silt and clay. These results expand the range of dynamic mud deposition into supercritical‐flow conditions, where local transient shear stress reduction rather than overall flow waning conditions allow for deposition of fines. Comparison of the experimental deposits with outcrop datasets composed of conglomerates to mudstones, shows significant similarities and highlights the role of hydraulic jumps, rather than overall flow condition changes, in producing lithologically and geometrically complex stratigraphy.

Citation

Ono, K., Plink‐Björklund, P., Eggenhuisen, J. T., & Cartigny, M. J. (2021). Froude supercritical flow processes and sedimentary structures:New insights from experiments with a wide range of grain sizes. Sedimentology, 68(4), 1328-1357. https://doi.org/10.1111/sed.12682

Journal Article Type Article
Acceptance Date Oct 29, 2019
Online Publication Date Nov 1, 2019
Publication Date May 24, 2021
Deposit Date Nov 6, 2019
Publicly Available Date Nov 6, 2019
Journal Sedimentology
Electronic ISSN 1365-3091
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 68
Issue 4
Pages 1328-1357
DOI https://doi.org/10.1111/sed.12682
Public URL https://durham-repository.worktribe.com/output/1284345

Files

Accepted Journal Article (10 Mb)
PDF

Copyright Statement
This is the accepted version of the following article: Ono, Kenya, Plink‐Björklund, Piret, Eggenhuisen, Joris T. & Cartigny, Matthieu J.B. (2019). Froude supercritical flow processes and sedimentary structures:New insights from experiments with a wide range of grain sizes. Sedimentology 68(4): 1328-1357, which has been published in final form at https://doi.org/10.1111/sed.12682.This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for self-archiving.






You might also like



Downloadable Citations