Processes of MISS-formation in a modern siliciclastic tidal flat, Patagonia (Argentina)

Maisano, Lucía; Cuadrado, Diana Graciela; Gómez, Eduardo A.

doi:10.1016/j.sedgeo.2018.12.002

Cited by 23 publications

(13 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1; Trebino, 1987). A semi-closed area behind the barrier is categorized as a supratidal zone because it is flooded by seawater only during storms that may occur up to 43 times per year, but remains unaffected by daily flood tides (details in Maisano et al, 2019;Perillo et al, 2019). This alternation between quiescence and flooding events provides optimal conditions for an epibenthic microbial mat to form (Noffke, 2010), which covers a wide area of ca 1.8 km 2 in size.…”

Section: Study Areamentioning

confidence: 99%

“…The episodic inundation of the area displays hydrodynamic conditions characterized by a fast flood and slow ebb. These characteristics are enhanced by the coastal geomorphology of the confined and elongated tidal flat (Maisano et al, 2019;Perillo et al, 2019). The narrowing produces a current amplification and the water column reaches a maximum of 78 cm over the colonized flat.…”

Section: Study Areamentioning

confidence: 99%

“…The narrowing produces a current amplification and the water column reaches a maximum of 78 cm over the colonized flat. The fast flood currents are the primary factor in developing large microbial deformation structures such as roll-ups and folds, several metres in size (Cuadrado et al, 2015;Maisano et al, 2019). These huge structures form simultaneously with ripples during a storm.…”

Section: Study Areamentioning

confidence: 99%

“…The large flood in June 2018 (arrow 1 in Fig. 3B) created erosional pockets and several mat deformation structures (details in Maisano et al, 2019) due to the detachment of the microbial mat from the underlying sediment. Water currents deformed the mat into roll-ups, and flipped-over edges; microbial gas domes formed by gas migrating vertically through the sediment, most likely deriving from the gas-filled sponge pores beneath the microbial mat ( Fig.…”

Section: Sediment Transport and Rippled Bed Developmentmentioning

confidence: 99%

“…This study was carried out in the supratidal flats in Paso Seco (Argentina), characterized by a strong, erosion-resistant microbial mat, which persists even under intermittent high-energy hydrodynamic events (Cuadrado & Pan, 2018;Maisano et al, 2019). The study documents how the ripple marks created during storms become stabilized by microbial activity that starts colonizing the fresh deposits, so that a flaser bedding is developed.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Geobiological model of ripple genesis and preservation in a heterolithic sedimentary sequence for a supratidal area

Cuadrado

2020

Sedimentology

Self Cite

View full text Add to dashboard Cite

This study documents the processes involved in forming flaser and wavy bedding governed by microbial activity in sediments. It focuses on a modern marginal‐tidal system providing evidence of the role that biofilms play in the stabilization of ripples and their potential preservation. A combination of detailed field work, analysis of water level records and microscopic petrographic inspection were used to reply to the question: how fine‐grained and coarse‐grained sediments can sequentially be deposited and preserved in a coastal environment. The hydraulic energy was measured by water level sensors recording flooding events that inundate the colonized tidal flat. Changing surface morphologies were monitored after storms, revealing the importance of biological processes in the preservation of ripples. A mud drape over ripples was observed several days after the undulated surface formation, known as a sinoidal sedimentary structure, which is a thin biofilm covering the ripples, caused by the presence of a microbial mat. Because bedforms are essential predictors of palaeoenvironmental reconstruction, interpretation in the geological record should take into consideration the important effect that colonized sediments have on the preservation of ripples. A geobiological model explains the flaser sedimentation, common in depositional coastal environments, suggesting that the hydrodynamic conditions may not be directly reflected by the grain size at the time of deposition. The study reveals that flaser sedimentation involves an interaction with benthic organisms, reflected by the sequence of microbial mats with sand ripple marks. A detailed description of heterolithic sequences shows that the presence of microbial activity can drive ripple preservation. This suggests that hydraulic interpretation of the sedimentary record based only on physical processes might be erroneous.

show abstract

Section: Study Areamentioning

confidence: 99%

Section: Study Areamentioning

confidence: 99%

Section: Study Areamentioning

confidence: 99%

Section: Sediment Transport and Rippled Bed Developmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations