Gravel Waves in an Ancient Canyon: Analogous Features and Formative Processes of Coarse-Grained Bedforms in a Submarine-Fan System, the Lower Pleistocene of the Boso Peninsula, Japan

Itô, Makoto; Saito, Takahiro

doi:10.2110/jsr.2006.093

Cited by 35 publications

(34 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Coarse-grained antidune bedforms have been described from several deep-marine channel outcrops (Ito and Saito, 2006;Ito, 2010;Lang et al, 2017), but were first described by Winn and Dott (1977) from the Lago Sofia conglomerates of the Cerro Toro, Formation. There, large gravel-bedforms, up to 4 m in height, with prominent backset bedding were interpreted to have developed under antidune flow conditions.…”

Section: Comparison To Other Overbank Sand Bars and Bedformsmentioning

confidence: 99%

“…These have been attributed to formation under Froude-subcritical flow conditions (densimetric Froude number <1, but see Huang et al, 2009) as internal lee waves (Flood, 1988;Kneller and Buckee, 2000;Lewis and Pantin, 2002), or to Froude-supercritical flow (Froude number >1), forming as antidunes (Normark et al, 1980;Wynn et al, 2000;Ercilla et al, 2002) or cyclic-steps (Cartigny et al, 2011;Kostic, 2011;Zhong et al, 2015). Beneath typical seismic resolution, smaller, coarser-grained overbank bedforms attributed to Froude-supercritical flow have been reported from seafloor channel-levee systems Wynn et al, 2002;Hughes Clarke, 2016;Hage et al, 2018) but only a few examples are known from outcrop studies (Winn and Dott, 1977;Ito and Saito, 2006;Lang et al, 2017), where high-resolution studies of the preserved sediments are possible.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Supercritical flows overspilling from bypass‐dominated submarine channels and the development of overbank bedforms

McArthur

Kane²,

Bozetti

et al. 2019

The Depositional Record

View full text Add to dashboard Cite

Overbank deposits of submarine channels are typically thin-bedded, fine-grained and predominantly characterized by a series of sedimentary structures interpreted to record a relatively simple history of waning flow. Here, a new type of bedform indicative of Froude-supercritical flow is reported from successions of thin-bedded turbidites interpreted as channel overbank deposits in the Upper Cretaceous Rosario Formation, Baja California, Mexico. A link is demonstrated between the development of overbank deposits in the form of depositional terraces or internal levees and contemporaneously active sediment transport, bypass and deposition of coarsergrained material in a channel. The overbank bedforms overlie an erosion surface and contain a suite of sedimentary structures indicative of initially Froude-supercritical flow conditions and a progressive waning of flow strength. In some cases, a stacked repetition of facies is interpreted to record a rejuvenation of flow energy. The characteristic sedimentary sequence observed is as follows: (a) long wavelength, low amplitude erosional surface with superimposed scours; (b) antidune backsets; (c) upper stage plane-parallel lamination; (d) subcritical climbing ripples; (e) supercritical climbing ripples; (f) lower stage planar laminated tops; (g) a sharp upper surface.The exact vertical sequence of sedimentary structures encountered varies depending on the point of observation with respect to the bedform crest and distance from the parent channel. The recognition of these distinctive bedforms allows for interpretation of sediment bypass and proximity to a channel thalweg. These bedforms have not hitherto been described and provide a further example of the range of flow processes operating in submarine channel-levee systems, which aids depositional environment interpretation in both subsurface and outcrop studies. K E Y W O R D SBaja California, deep-marine, Rosario Formation, slope channels, turbidity currents, Upper Cretaceous |McARTHUR eT Al.

show abstract

Section: Comparison To Other Overbank Sand Bars and Bedformsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Supercritical flows overspilling from bypass‐dominated submarine channels and the development of overbank bedforms

McArthur

Kane²,

Bozetti

et al. 2019

The Depositional Record

View full text Add to dashboard Cite

show abstract

“…These bedforms have a predictable internal layering and are usually interpreted as being produced by the combination of erosion and deposition caused by tractive forces. Submarine canyons are commonly viewed as the conduits through which turbidity currents fl ow, feeding the submarine fans below (Bouma, 2000;Ito and Saito, 2006).…”

Section: Formation Of Large Crescent-shaped Bedformsmentioning

confidence: 99%

Origins of large crescent-shaped bedforms within the axial channel of Monterey Canyon, offshore California

et al. 2010

View full text Add to dashboard Cite

Crescent-shaped bedforms with wavelengths from 20 to 80 m, amplitudes to 2.5 m, and concave down-canyon crests occur in the axial channel of Monterey Canyon (offshore California, USA) in water depths from 11 to more than 350 m. The existence of these features may be an important new clue as to how sediment moves through submarine canyons. Three complementary studies were initiated in 2007 to understand the origin and evolution of these bedforms. (1) Vibracoring. Three transects of closely spaced remotely operated vehicle-collected vibracores were obtained across these bedforms. The seafl oor underneath these features is composed of gravity-fl ow deposits. (2) Acoustic array. Three boulder-sized concrete monuments containing acoustic beacons were buried just below the surface of the canyon fl oor in ~290 m water depth and their locations were redetermined on 17 subsequent occasions. Although the beacons became more deeply buried >0.6 m below the seafl oor, they still could be tracked acoustically. Over a 26-month period the position of 1 or more of the beacons moved down-canyon during at least 6 discrete transport events for a total displacement of 994-1676 m. The movement and burial of the monuments suggest that the seabed was mobilized to >1 m depth during gravity-fl ow events. (3) Autonomous underwater vehicle (AUV) repeat mapping. AUV-acquired high-resolution multibeam mapping , and CHIRP (compressed highintensity radar pulse) subbottom profi ling surveys of the seafl oor in the active channel were repeated four times in the fi rst half of 2007. In addition, the movement of large instrument frames deployed in 2001-2003 within the axis of Monterey Canyon in the area now known to be associated with the crescent-shaped bedforms is documented.The fate of the frames has helped elucidate the frequency, transport potential, and processes occurring within the axis of Monterey Canyon associated with these bedforms. The crescent-shaped bedforms appear to be produced during brief gravity-fl ow events that occur multiple times each year, commonly coincident with times of large signifi cant wave heights. Whether the bedforms are generated by erosion associated with cyclic steps in turbidity fl ows or internal deformation associated with slumping during gravity-fl ow events remains unclear.

show abstract

“…Gently undulating waveforms observed in outcrop sections parallel to the paleoflow direction to the west are interpreted to be equivalent to those of coarse-grained sediment waves in the sense of Wynn et al (2002), which have also been documented in deepwater successions (Vicente Bravo and Robles, 1995;Ito and Saito, 2006;Ito, 2010;Ito et al, 2014). Although some ancient examples of coarse-grained sediment waves are interpreted to have formed as downstream-migrating three-dimensional antidunes (Ito, 2010), other modern and ancient coarse-grained sediment waves, consisting mainly of sandy deposits, indicate the upstream migration of bedforms (e.g., Smith et al, 2007;Ponce and Carmona, 2011;Symons et al, 2016).…”

Section: Discussionmentioning

confidence: 78%

Geometry and lithofacies of coarse-grained injectites and extrudites in a late Pliocene trench-slope basin on the southern Boso Peninsula, Japan

Itô

Ishimoto

Ito

et al. 2016

Sedimentary Geology

View full text Add to dashboard Cite

Gravel Waves in an Ancient Canyon: Analogous Features and Formative Processes of Coarse-Grained Bedforms in a Submarine-Fan System, the Lower Pleistocene of the Boso Peninsula, Japan

Cited by 35 publications

References 30 publications

Supercritical flows overspilling from bypass‐dominated submarine channels and the development of overbank bedforms

Supercritical flows overspilling from bypass‐dominated submarine channels and the development of overbank bedforms

Origins of large crescent-shaped bedforms within the axial channel of Monterey Canyon, offshore California

Geometry and lithofacies of coarse-grained injectites and extrudites in a late Pliocene trench-slope basin on the southern Boso Peninsula, Japan

Contact Info

Product

Resources

About