The shell pavement below oceanic turbidites

Kuenen, Ph. H.

doi:10.1016/0025-3227(64)90041-6

Cited by 17 publications

(11 citation statements)

References 4 publications

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“…This relation rules out the variable current explanation. But the suggestion of stronger currents with a variable source is also excluded by the discovery of a thin shell pavement exclusively below fine-grained deep-sea sands ( NESTEROFF, 1963 ; see also KUENEN, 1964b). This shows that with coarse-grained beds deposition was preceded by a more competent current stage but not in the case of fine-grained ones.…”

Section: Loading Of the Currentmentioning

confidence: 99%

Emplacement of Flysch‐type Sand Beds

Kuenen

1967

Sedimentology

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SUMMARY Recently several attempts have been made to explain deep‐sea sands or flysch‐type sandstone beds by normal currents, instead of by turbidity currents. The arguments that are offered against turbidity currents and those in favour of normal currents are inconclusive. Current measurements and calculations indicate 1 m from the bottom on abyssal plains velocities are less than 30 cm/sec. The ubiquitous structures: sole markings, graded bedding, fine‐grained ripple mark between a lower and a covering set of horizontal laminae, and convolution, are shown each in turn to be inexplicable on the basis of normal traction currents and the same holds for the uniform bed thickness. On the other hand these features develop readily in a circular flume from overloaded suspension currents. These experiments show that to support a heavy charge of fine sand in a clay suspension a current must exceed 100 cm/sec, and in clear water double that amount is needed. The inadequacy of normal currents both in velocity and kind is thus established. This lends powerful support to the case for turbidity currents. Many authors claim to have found evidence for the deflection of turbidity currents or for currents flowing across the paleo‐slope. Explanations offered include the Coriolis force, normal currents, multiple turbidity currents, or surge waves. Analysis shows that all are open to serious doubts. The author suggests, quite tentatively, that the deflections may be only simulated by the development of lamination and grain orientation oblique and perpendicular to the current direction. Sagging of the trough floor may also play a part by confusing the determination of paleo‐slope. Another possibility is that the turbidity current deviated from its original direction by “internal slope”, by momentum, by centrifugal force, or by lack of space. Admittedly, a problem remains, for the swift deposition deduced from the climbing ripples is in contradiction with the supposed stretching of the turbidity current inferred from grading.

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Section: Loading Of the Currentmentioning

confidence: 99%

Emplacement of Flysch‐type Sand Beds

Kuenen

1967

Sedimentology

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“…The occurrence of both turbiditic and non-turbiditic layers among these fine-grained rocks is now generally acknowledged (Enos, 1969;Hesse, 1969Hesse, , 1972Hesse, , 1973Thomson & Thomasson, 1969;Roy, 1970;Weiler, 1970;Scholle, 1971;Hall & Stanley, 1972;Mutti & Ricci Lucchi, 1972;Piper, 1972Piper, , 1973Lajoie & Chagnon, 1973;Wezel, 1973;Rupke & Stanley, 1974. Earlier references are given by Kuenen, 1964). However, transport and deposition of both types of fine-grained deposits raises a number of unsolved problems.…”

Section: Introductionmentioning

confidence: 99%

“…the fine-grained material deposited from the tail of a turbidity current, and the hemipelagic or pelagic F-division representing the most common example of an interturbidite layer. (The term F-division proposed by Van der Lingen, 1969, is recommended here instead of the designations et and ep proposed by Kuenen, 1964.) Some progress has been made in this field since Bouma's original work, but much of it appears to have not yet become common knowledge, as shown by recent textbooks (e.g.…”

Section: Introductionmentioning

confidence: 99%

Turbiditic and non‐turbiditic mudstone of Cretaceous flysch sections of the East Alps and other basins

Hesse

1975

Sedimentology

105

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Recognition of the occurrence and extent of hemipelagic and pelagic deposits in turbidite sequences is of considerable importance for environmental analysis (palaeodepth, circulation, distance from land, hemipelagic or pelagic versus turbidite sedimentation rates) of ancient basins. Differentiation between the finegrained parts (E‐division) of turbidites and the (hemi‐) pelagic layers (F‐division of turbidite‐pelagite alternations) is facilitated in basins where carbonate turbidites were deposited below the carbonate compensation depth (CCD) such as the Flysch Zone of the East Alps but may be difficult in other basins where less compositional contrast is developed between the fine‐grained turbidites and hemipelagites. This difficulty pertains particularly in Palaeozoic and older basins. For Late Mesozoic‐Cenozoic oceans with a relatively deep calcite compensation level three other types of turbidite basins may be distinguished for which differentiation becomes increasingly more difficult in the sequence from (1) to (3): (1) terrigenous turbidite basins above the CCD; (2) carbonate turbidite basins above the CCD; (3) terrigenous turbidite basins below the CCD. Criteria and methods useful for the differentiation between turbiditic and hemipelagic mudstone in the Upper Cretaceous of the Flysch Zone of the East Alps include calcium carbonate content, colour, sequential analysis, distribution of bioturbation, and microfaunal content. In modern turbidite basins clay mineral content, organic matter content, plant fragments, and grain‐size (graded bedding, maximum grain diameter) have reportedly also been used as criteria (see Table 3). Deposition of muddy sediment by turbidity currents on weakly sloping sea bottoms such as the distal parts of deep‐sea fans or abyssal plains is not only feasible but may lead to the accumulation of thick layers. Contrary to earlier speculation it can be explained by the hydrodynamic theory of turbidity currents, if temperature differences between the turbidity current and the ambient deep water as well as relatively high current velocities for the deposition of turbiditic muds (an order of magnitude higher on mud surfaces than commonly assumed) are taken into consideration. The former add to the capacity of turbidity currents to carry muddy sediment without creating a driving force on a low slope.

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“…Van der Lingen (1969) divided this unit into a pelitic interval (E), deposited from the dilute suspension cloud left behind by the passing turbidity current, and the overlying pelagic interval (F) represented by sediment deposited between successive turbidity currents. Kuenen (1964) used the symbols et and e p to describe the same turbiditic and pelagic or hemipelagic units. However, as stated by Hesse (1975) 'the biggest problem is still, in many cases, the distinction between the turbiditic and the non-turbiditic sediments, as shown by the degree of uncertainty expressed with respect to this question in many published reports'.…”

Section: Introductionmentioning

confidence: 99%

Use of clay fabric to distinguish turbiditic and hemipelagic siltstones and silts

1980

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Pliocene and Holocene siltstones and silts in outcrops from the Boso Peninsula, Japan and in cores from the East China were studied to determine distinctive characteristics of the turbiditic (Bouma E‐Division) and hemipelagic siltstones and silts. Weathering characteristics, colour, grain size, and organic carbon‐organic nitrogen ratio, plus clay fabric proved valuable in characterizing each unit. Clay and non‐clay mineral content was uniform throughout. Clay fabric differences are pronounced. Random clay flake orientation prevails in the turbiditic interval while the hemipelagic unit has more preferred orientation. The fabric reflects different conditions of sedimentation. The turbiditic clay was deposited more rapidly in the flocculated state while the interturbidite hemipelagic clay may have formed from more slowly sedimented dominantly dispersed clay. Results suggest that clay fabric may be useful in combination with other sedimentary features in the study of mud‐turbidite sedimentation.

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The shell pavement below oceanic turbidites

Cited by 17 publications

References 4 publications

Emplacement of Flysch‐type Sand Beds

Emplacement of Flysch‐type Sand Beds

Turbiditic and non‐turbiditic mudstone of Cretaceous flysch sections of the East Alps and other basins

Use of clay fabric to distinguish turbiditic and hemipelagic siltstones and silts

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