Seismic evidence of widespread mass transport deposits in the Rhône deep-sea fan: Their role in the fan construction

<p>It is hypothesized that submarine transport of sediments down a continental slope induce physical disintegration of pristine (non-broken) foraminifera shells, and thus mass transport deposits should include a significant percentage of fragmented shells. To validate this hypothesis, we studied two gravity-cores from the Eastern-Mediterranean continental slope, offshore Israel: AM113 sampled within a landslide lobe at 848 m water depth, and AM015 located away from a landslide at 1080 m. At least one interval, ~0.5 m thick, of massive sediments hosting mud-clasds (i.e. debrite) was identified within each core. The timing of these debrites, based on biostratigraphy, oxygen isotopes and total organic carbon data, predates sapropel S1 in both cores and is contemporaneous (AM113) or slightly predates (AM015) the most recent deglaciation.</p><p>We found a noticeable increase in benthic and planktic foraminiferal shells fragmentation through the last deglaciation and up to the base of S1. This strongly-fragmented sequence is located in the debrite of AM113 but it is overlaying the debrite of AM015. Accordingly, we suggest two possible mechanisms for the increased fragmentation of foraminiferal shells in both cores: Sediment transport and turbulence related to submarine mass-transport events, or geochemical changes in the lower water column properties at the transition from MIS-2 to the Holocene.</p>

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A deep subaqueous fan depositional model for the Palaeoarchaean (3.46 Ga) Marble Bar Cherts, Warrawoona Group, Western Australia

Geological Magazine ◽

10.1017/s0016756812000131 ◽

2012 ◽

Vol 149 (4) ◽

pp. 743-749 ◽

Cited By ~ 4

Author(s):

NICOLAS OLIVIER ◽

GILLES DROMART ◽

NICOLAS COLTICE ◽

NICOLAS FLAMENT ◽

PATRICE REY ◽

...

Keyword(s):

Mass Transport ◽

Western Australia ◽

Deep Sea ◽

High Density ◽

Turbidity Currents ◽

Low Density ◽

Depositional Model ◽

Sea Fan ◽

Pilbara Craton ◽

Channel Systems

AbstractThe 3.46 Ga Marble Bar Chert Member of the East Pilbara Craton, Western Australia, is one of the earliest and best-preserved sedimentary successions on Earth. Here, we interpret the finely laminated thin-bedded cherts, mixed conglomeratic beds, chert breccia beds and chert folded beds of the Marble Bar Chert Member as the product of low-density turbidity currents, high-density turbidity currents, mass transport complexes and slumps, respectively. Integrated into a channel-levee depositional model, the Marble Bar Chert Member constitutes the oldest documented deep-sea fan on Earth, with thin-bedded cherts, breccia beds and slumps composing the outer levee facies tracts, and scours and conglomeratic beds representing the channel systems.

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Mass-transport Deposits of the Upper Cretaceous Qingshankou Formation, Songliao Terrestrial Basin, Northeast China: Depositional Characteristics, Recognition Criteria and External Geometry

Acta Geologica Sinica - English Edition ◽

10.1111/1755-6724.12183 ◽

2014 ◽

Vol 88 (1) ◽

pp. 62-77 ◽

Cited By ~ 11

Author(s):

Shuxin PAN ◽

Pingsheng WEI ◽

Tianqi WANG ◽

Caiyan LIU ◽

Bintao CHEN ◽

...

Keyword(s):

Mass Transport ◽

Northeast China ◽

Upper Cretaceous ◽

Mass Transport Deposits

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Stratigraphic revision and reconstruction of the deep-sea fan of the Voirons Flysch (Voirons Nappe, Chablais Prealps)

Swiss Journal of Geosciences ◽

10.1186/s00015-020-00383-1 ◽

2021 ◽

Vol 114 (1) ◽

Author(s):

Jérémy Ragusa ◽

Lina Maria Ospina-Ostios ◽

Pascal Kindler ◽

Mario Sartori

Keyword(s):

Deep Sea ◽

Distal Part ◽

Accretionary Prism ◽

Proximal Part ◽

Late Eocene ◽

Lithostratigraphic Units ◽

Stratigraphic Record ◽

Sea Fan ◽

Stratigraphic Evolution ◽

Depositional Setting

AbstractThe Voirons Flysch (Caron in Eclogae Geologicae Helvetiae 69:297–308, 1976), is a flysch sequence aggregated into the sedimentary accretionary prism of the Chablais and Swiss Prealps. Its palaeogeographic location is still debated (South Piemont or Valais realm). We herein present a stratigraphic revision of the westernmost unit of the former Gurnigel Nappe sensu Caron (Eclogae Geologicae Helvetiae 69:297–308, 1976): the Voirons Flysch. This flysch is subdivided into three lithostratigraphic units at the formation level (the Voirons Sandstone, the Vouan Conglomerate, the Boëge Marl), with an additional unit (Bruant Sandstone) of uncertain attribution, ranging from the early Eocene to probably the late Eocene. We further propose a new model of the depositional setting of the deep-sea of the Voirons Flysch based on palaeocurrent directions, the overall geometry and sedimentary features. This model depicts an eastward deflected deep-sea fan. The stratigraphic record of the proximal part of this fan is fairly complete in the Voirons area, whereas its most distal part is only represented by one small exposure of thinly bedded sandstones in the Fenalet quarry. The stratigraphic evolution of the Voirons Flysch shows two major disruptions of the detrital sedimentation at the transition between Voirons Sandstone—Vouan Conglomerate and Vouan Conglomerate—Boëge Marl. The cause of these disturbances has to be constrained in the framework of the palaeogeographic location of the Voirons Flysch.

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