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The role of biophysical cohesion on subaqueous bed form size
Author(s) -
Parsons Daniel R.,
Schindler Robert J.,
Hope Julie A.,
Malarkey Jonathan,
Baas Jaco H.,
Peakall Jeffrey,
Manning Andrew J.,
Ye Leiping,
Simmons Steve,
Paterson David M.,
Aspden Rebecca J.,
Bass Sarah J.,
Davies Alan G.,
Lichtman Ian D.,
Thorne Peter D.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl067667
Subject(s) - cohesion (chemistry) , geology , sedimentary rock , sediment , sedimentary structures , silt , sediment transport , geotechnical engineering , geomorphology , sedimentary depositional environment , geochemistry , chemistry , organic chemistry , structural basin
Biologically active, fine‐grained sediment forms abundant sedimentary deposits on Earth's surface, and mixed mud‐sand dominates many coasts, deltas, and estuaries. Our predictions of sediment transport and bed roughness in these environments presently rely on empirically based bed form predictors that are based exclusively on biologically inactive cohesionless silt, sand, and gravel. This approach underpins many paleoenvironmental reconstructions of sedimentary successions, which rely on analysis of cross‐stratification and bounding surfaces produced by migrating bed forms. Here we present controlled laboratory experiments that identify and quantify the influence of physical and biological cohesion on equilibrium bed form morphology. The results show the profound influence of biological cohesion on bed form size and identify how cohesive bonding mechanisms in different sediment mixtures govern the relationships. The findings highlight that existing bed form predictors require reformulation for combined biophysical cohesive effects in order to improve morphodynamic model predictions and to enhance the interpretations of these environments in the geological record.